Estimation of net primary productivity using a process-based model in Gansu Province, Northwest China

Energy Technology Data Exchange (ETDEWEB)

Wang, Peijuan; Xie, Donghui; Zhou, Yuyu; E, Youhao; Zhu, Qijiang

2014-01-16

The ecological structure in the arid and semi-arid region of Northwest China with forest, grassland, agriculture, Gobi, and desert, is complex, vulnerable, and unstable. It is a challenging and sustaining job to keep the ecological structure and improve its ecological function. Net primary productivity (NPP) modeling can help to improve the understanding of the ecosystem, and therefore, improve ecological efficiency. The boreal ecosystem productivity simulator (BEPS) model provides the possibility of NPP modeling in terrestrial ecosystem, but it has some limitations for application in arid and semi-arid regions. In this paper we improve the BEPS model, in terms of its water cycle by adding the processes of infiltration and surface runoff, to be applicable in arid and semi-arid regions. We model the NPP of forest, grass, and crop in Gansu Province as an experimental area in Northwest China in 2003 using the improved BEPS model, parameterized with moderate resolution remote sensing imageries and meteorological data. The modeled NPP using improved BEPS agrees better with the ground measurements in Qilian Mountain than that with original BEPS, with a higher R2 of 0.746 and lower root mean square error (RMSE) of 46.53 gC/m2 compared to R2 of 0.662 and RMSE of 60.19 gC/m2 from original BEPS. The modeled NPP of three vegetation types using improved BEPS show evident differences compared to that using original BEPS, with the highest difference ratio of 9.21% in forest and the lowest value of 4.29% in crop. The difference ratios between different vegetation types lie on the dependence on natural water sources. The modeled NPP in five geographic zones using improved BEPS are higher than those with original BEPS, with higher difference ratio in dry zones and lower value in wet zones.

Correlation and SVD Analysis of Anomalous Spring Precipitation in Northwest China and Sea Surface Temperature in Key Region in Recent 50 Years

Institute of Scientific and Technical Information of China (English)

无

2011-01-01

[Objective] The aim was to study the relationship between spring precipitation anomaly in Northwest China and sea surface temperature anomaly (SSTA) in Key region in recent 50 years. [Method] Based on monthly average precipitation in Northwest China and global monthly sea surface temperature (SST) grid data, the effects of SSTA in equatorial central and eastern Pacific on spring precipitation in Northwest China were discussed by means of correlation and SVD analysis. [Result] For spring precipitation in Nor...

Modelling Snowmelt Runoff under Climate Change Scenarios in an Ungauged Mountainous Watershed, Northwest China

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Yonggang Ma

2013-01-01

Full Text Available An integrated modeling system has been developed for analyzing the impact of climate change on snowmelt runoff in Kaidu Watershed, Northwest China. The system couples Hadley Centre Coupled Model version 3 (HadCM3 outputs with Snowmelt Runoff Model (SRM. The SRM was verified against observed discharge for outlet hydrological station of the watershed during the period from April to September in 2001 and generally performed well for Nash-Sutcliffe coefficient (EF and water balance coefficient (RE. The EF is approximately over 0.8, and the water balance error is lower than ± 10%, indicating reasonable prediction accuracy. The Statistical Downscaling Model (SDSM was used to downscale coarse outputs of HadCM3, and then the downscaled future climate data were used as inputs of the SRM. Four scenarios were considered for analyzing the climate change impact on snowmelt flow in the Kaidu Watershed. And the results indicated that watershed hydrology would alter under different climate change scenarios. The stream flow in spring is likely to increase with the increased mean temperature; the discharge and peck flow in summer decrease with the decreased precipitation under Scenarios 1 and 2. Moreover, the consideration of the change in cryosphere area would intensify the variability of stream flow under Scenarios 3 and 4. The modeling results provide useful decision support for water resources management.

Community Service, Educational Performance and Social Responsibility in Northwest China

Science.gov (United States)

Luo, Renfu; Shi, Yaojiang; Zhang, Linxiu; Liu, Chengfang; Li, Hongbin; Rozelle, Scott; Sharbono, Brian

2011-01-01

The main goal of this paper is to analyse the effect of high school scholarships tied to community service on the development of secondary school students in Northwest China. Using data from three rounds of surveys of thousands of students in 298 classes in 75 high schools in Shaanxi province, the paper documents the implementation of the…

Spatio-temporal availability of field crop residues for biofuel production in Northwest and Southwest China

NARCIS (Netherlands)

Han, L.; Wang, X.; Spiertz, J.H.J.; Yang, L.; Zhou, Y.; Liu, J.; Xie, G.

2015-01-01

Developing bioenergy from plant feedstocks is considered an opportunity to reduce greenhouse gas emissions and secure biofuel supply. This study is an assessment of the availability of field crop residues for bioenergy feedstocks in northwest China (NWC) and southwest China (SWC). The amount of

Northwest disposal site for LLW and ILW in China radioactive impact assessment

International Nuclear Information System (INIS)

Wei Kuizi; He Chunying; Lu Baozhen; Li Tingjun

1993-01-01

This paper describes the studies and main conclusions in site selection, design, and radioactive impact assessment of the Northwest Disposal Site of China for intermediate- and low-level radioactive wastes. At the end of the paper, further works are proposed

Modelling the Effects of Temperature and Cloud Cover Change on Mountain Permafrost Distribution, Northwest Canada

Science.gov (United States)

Bonnaventure, P. P.; Lewkowicz, A. G.

2008-12-01

Spatial models of permafrost probability for three study areas in northwest Canada between 59°N and 61°N were perturbed to investigate climate change impacts. The models are empirical-statistical in nature, based on basal temperature of snow (BTS) measurements in winter, and summer ground-truthing of the presence or absence of frozen ground. Predictions of BTS values are made using independent variables of elevation and potential incoming solar radiation (PISR), both derived from a 30 m DEM. These are then transformed into the probability of the presence or absence of permafrost through logistic regression. Under present climate conditions, permafrost percentages in the study areas are 44% for Haines Summit, British Columbia, 38% for Wolf Creek, Yukon, and 69% for part of the Ruby Range, Yukon (Bonnaventure and Lewkowicz, 2008; Lewkowicz and Bonaventure, 2008). Scenarios of air temperature change from -2K (approximating Neoglacial conditions) to +5K (possible within the next century according to the IPCC) were examined for the three sites. Manipulations were carried out by lowering or raising the terrain within the DEM assuming a mean environmental lapse rate of 6.5K/km. Under a -2K scenario, permafrost extent increased by 22-43% in the three study areas. Under a +5K warming, permafrost essentially disappeared in Haines Summit and Wolf Creek, while in the Ruby Range less than 12% of the area remained perennially frozen. It should be emphasized that these model predictions are for equilibrium conditions which might not be attained for several decades or longer in areas of cold permafrost. Cloud cover changes of -10% to +10% were examined through adjusting the partitioning of direct beam and diffuse radiation in the PISR input field. Changes to permafrost extent were small, ranging from -2% to -4% for greater cloudiness with changes of the opposite magnitude for less cloud. The results show that air temperature change has a much greater potential to affect mountain

Registration and management of community patients with tuberculosis in north-west China

NARCIS (Netherlands)

Wang, X.; Cai, J.; Wang, D.; Wang, Q.; Liang, H.; Ma, A.; Schouten, E.G.; Kok, F.J.

2015-01-01

OBJECTIVES: To describe the registration, management and characteristics of patients with tuberculosis (TB) in north-west China, and investigate whether patients with TB were diagnosed and treated in a timely manner.STUDY DESIGN: Health-facility-based retrospective data were collected from district

Association of obesity with socioeconomic status among adults of ages 18 to 80?years in rural Northwest China

OpenAIRE

Pei, Leilei; Cheng, Yue; Kang, Yijun; Yuan, Shuyi; Yan, Hong

2015-01-01

Background Understanding social disparities in obesity are presently an essential element in establishing public health priorities. However, the association between socioeconomic status (SES) and obesity has not been assessed in rural Northwest China. This study aims to explore the effect of SES on overweight/obesity and abdominal obesity by gender and age in rural Northwest China. Methods A total of 3030 participants between the ages of 18 to 80?years from rural Hanzhong, Shaanxi province, N...

Rabies Outbreaks and Vaccination in Domestic Camels and Cattle in Northwest China.

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Ye Liu

2016-09-01

Full Text Available In contrast to many countries where rabies has been well controlled in humans and livestock, even in wildlife, rabies is still endemic in almost regions of China. In Northwest China, rabies transmitted by stray dogs and wild foxes has caused heavy economic losses to local herdsmen, as well as causing numbers of human cases. In this study, as part of an investigation of ways to prevent rabies epidemics in livestock, we report an analysis of domestic cattle and camel rabies cases in Ningxia Hui (NHAR and Inner Mongolia Autonomous Region (IMAR and the immune efficacy of canine inactivated rabies vaccines in these animals. We found that rabies viruses from these animals are closely related to dog-hosted China I and fox-associated China III lineages, respectively, indicating that the infections originated from two different sources (dogs and wild foxes. As well as the previously reported Arctic and Arctic-related China IV lineage in IMAR, at least three separate phylogenetic groups of rabies virus consistently exist and spread throughout Northwest China. Since there is no licensed oral vaccine for wild foxes and no inactivated vaccine for large livestock, local canine inactivated vaccine products were used for emergency immunization of beef and milk cattle and bactrian (two-humped camels in local farms. Compared with a single injection with one (low-efficacy or three doses (high-cost, a single injection of a double dose of canine vaccine provided low-price and convenience for local veterinarians while inducing levels of virus neutralizing antibodies indicative of protection against rabies for at least 1 year in the cattle and camels. However, licensed vaccines for wildlife and large domestic animals are still needed in China.

AHP 46: AN UNEXPECTED GIFT FROM THE GODS: BOYHOOD IN NORTHWEST CHINA

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Yang Jialiang 杨佳亮

2017-04-01

Full Text Available My name is Chao. I'm an ordinary person from a poor mountain village in northwest China. Like most other human beings, I often ponder: Why do I exist? How should I live? What is the meaning of my life? I believe my life is not worthless. Everyone should be appreciated and each of us should be valued as a wonderful individual. This is why I wrote this book - to share with others the narrative of my life; to allow others to know another human being's life story. My parents had two children. Brother was born in 1982 and 10 years later in 1992, I was born. Mother was then 38 and Father was 42. I was an accident. My parents had decided to give me away because they were afraid of violating the one-child policy and because they were so poor. They had decided to give me to a rich family who would in return give them a truck. However, at that time Brother was very attached to me. He cried a lot when he heard that my parents would give me away. My parents then decided to keep me no matter the difficulties they faced.

Potential Risk Assessment of Mountain Torrent Disasters on Sloping Fields in China

Science.gov (United States)

GAO, X.

2017-12-01

China's sloping fields have the problems of low production and serious soil erosion, and mountain torrent disasters will bring more serious soil and water loss to traditional extensive exploitation of sloping field resources. In this paper, China's sloping fields were classified into three grades, such as slightly steep, steep and very steep grade. According to the geological hazards prevention and control regulation, the historical data of China's mountain torrent disasters were spatially interpolated and divided into five classes, such as extremely low, low, middle, high and extremely high level. And the risk level map of mountain torrents was finished in ArcGIS. By using overlaying analysis on sloping fields and risk level map, the potential risk regionalization map of sloping fields in various slope grades was obtained finally. The results shows that the very steep and steep sloping fields are mainly distributed in the first or second stage terraces in China. With the increase of hazard risk level, the area of sloping fields decreases rapidly and the sloping fields in extremely low and low risk levels of mountain torrents reach 98.9%. With the increase of slope grade, the area of sloping fields in various risk levels also declines sharply. The sloping fields take up approximately 60 65% and 26 30% in slightly steep and steep grade areas separately at different risk level. The risk regionalization map can provide effective information for returning farmland to forests or grassland and reducing water and soil erosion of sloping fields in the future.

Emergy evaluation of agricultural sustainability of Northwest China before and after the grain-for-green policy

International Nuclear Information System (INIS)

Wang, Xiuhong; Shen, Jianxiu; Zhang, Wei

2014-01-01

China’s grain-for-green policy (GFGP) was implemented with the goal of improving ecological security. Consequently, agricultural energy and agrochemical inputs have been significantly increased to improve food security and to increase the income of farmers in the regions where the GFGP was implemented. In analysis of the sustainability of the agricultural system affected by the GFGP, it is essential to consider both economic profitability and environmental sustainability. Using Yanchi County as a case study area, this study used an emergy synthesis to examine the sustainability of the agricultural system before and after the GFGP in Northwest China. We found that the total emergy input and energy output of the agricultural system in the study area increased from 1991 to 2008; however, the sustainability of the system declined, and this decline was especially evident after the GFGP was launched in 2001. Increasing inputs of non-renewable purchased resources will not only reduce the effectiveness of the GFGP in Northwest China, but also hinder the implementation of the energy-saving and emission-reduction policy that China launched in 2005. We suggest that sustainable agricultural development in Northwest China should be based on effective use of renewable resources and development of a low-carbon agricultural economy. - Highlights: • The total emergy input and energy output of the study system increased from 1991 to 2008. • The change of each emergy index was more evident after the GFGP launched in 2001. • The increase in input of non-renewable purchased resources will gradually reduce the function of the GFGP in West China. • Agricultural development in West China should be based on organic agriculture

Distribution and migration mechanism of fluoride in groundwater in the Manas River Basin, Northwest China

Science.gov (United States)

Liu, Yalei; Jin, Menggui; Ma, Bin; Wang, Jianjun

2018-04-01

Elevated fluoride (F) concentration in groundwater is posing a public health risk in the Manas River Basin (MRB), Northwest China. Based on the characterization of regional groundwater flow, 90 groundwater samples from aquifers were analyzed, along with top-soil leachate and pore-water samples from aquitards. Stable oxygen (δ18O) and hydrogen isotopes, radiocarbon and hydrochemical analyses of the groundwater and pore-water samples were conducted to trace groundwater hydrological and hydrochemical processes and thereby understand the distribution and migration mechanism of F. The groundwater is recharged by meteoric precipitation through vapor condensation processes in the Tianshan Mountains. The F concentration in groundwater samples from this basin ranged from 0.11 to 48.15 mg/L (mean 2.56 mg/L). In 37 of the 90 groundwater samples, the F concentrations were above the safe level for drinking water. The F concentrations progressively increased with the residence time and well depths in the northwest of the alluvial-fluvial plain, where groundwater is overexploited for agricultural and domestic use. Positive correlations between F and sodium (Na)/calcium (Ca) indicate that the enrichment and migration of F are influenced by cation exchange processes under high-Na and alkaline pH conditions. The relationships between δ18O and F and chloride (Cl) concentrations were nonlinear due to leaching and mixing processes. This shows that vertical leaching by irrigation return flow and mixing with pore water are the dominant processes driving the migration of F in the groundwater flow system of MRB, in addition to geochemical processes.

Future Projection with an Extreme-Learning Machine and Support Vector Regression of Reference Evapotranspiration in a Mountainous Inland Watershed in North-West China

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Zhenliang Yin

2017-11-01

Full Text Available This study aims to project future variability of reference evapotranspiration (ET0 using artificial intelligence methods, constructed with an extreme-learning machine (ELM and support vector regression (SVR in a mountainous inland watershed in north-west China. Eight global climate model (GCM outputs retrieved from the Coupled Model Inter-comparison Project Phase 5 (CMIP5 were employed to downscale monthly ET0 for the historical period 1960–2005 as a validation approach and for the future period 2010–2099 as a projection of ET0 under the Representative Concentration Pathway (RCP 4.5 and 8.5 scenarios. The following conclusions can be drawn: the ELM and SVR methods demonstrate a very good performance in estimating Food and Agriculture Organization (FAO-56 Penman–Monteith ET0. Variation in future ET0 mainly occurs in the spring and autumn seasons, while the summer and winter ET0 changes are moderately small. Annually, the ET0 values were shown to increase at a rate of approximately 7.5 mm, 7.5 mm, 0.0 mm (8.2 mm, 15.0 mm, 15.0 mm decade−1, respectively, for the near-term projection (2010–2039, mid-term projection (2040–2069, and long-term projection (2070–2099 under the RCP4.5 (RCP8.5 scenario. Compared to the historical period, the relative changes in ET0 were found to be approximately 2%, 5% and 6% (2%, 7% and 13%, during the near, mid- and long-term periods, respectively, under the RCP4.5 (RCP8.5 warming scenarios. In accordance with the analyses, we aver that the opportunity to downscale monthly ET0 with artificial intelligence is useful in practice for water-management policies.

Tourism: an alternative to development?: reconsidering farming, tourism and conservation incentives in Northwest Yunnan mountainous communities

OpenAIRE

Yang, Mingyu; Hens, Luc; Ou, XiaoKun; De Wulf, Robert

2009-01-01

In the last decade, tourism has developed rapidly in the mountainous areas of northwest Yunnan. This growth has led to substantial economic and social changes, with resulting environmental consequences. This article uses a case study to illustrate how local farmers involved in tourism changed their agricultural practices as a result of the transformations that took place in the area. The aim was to examine tourism's expected benefits of poverty alleviation and conservation incentives. Tourism...

First report of Toxoplasma gondii infection in market-sold adult chickens, ducks and pigeons in northwest China

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Cong Wei

2012-06-01

Full Text Available Abstract Background Toxoplasma gondii infection is a global concern, affecting a wide range of warm-blooded animals and humans worldwide, including poultry. Domestic and companion birds are considered to play an important role in the transmission of T. gondii to humans and other animals. However, little information on T. gondii infection in domestic birds in Lanzhou, northwest China was available. Therefore, this study was performed to determine the seroprevalence of T. gondii infection in domestic birds in Lanzhou, northwest China. Methods In the present study, the seroprevalence of T. gondii antibodies in 413 (305 caged and 108 free-range adult chickens, 334 (111 caged and 223 free-range adult ducks and 312 adult pigeons in Lanzhou, northwest China, were examined using the modified agglutination test (MAT. Results 30 (7.26% chickens, 38 (11.38% ducks and 37 (11.86% pigeons were found to be positive for T. gondii antibodies at the cut-off of 1:5. The prevalences in caged and free-range chickens were 6.23% and 10.19% respectively, however, statistical analysis showed that the difference was not significant (P > 0.05. The seroprevalences in caged and free-range ducks were 6.31% and 13.90% respectively, but the difference was not statistically significant (P > 0.05. Conclusions The results of the present survey indicated the presence of T. gondii infection in adult chickens, ducks and pigeons sold for meat in poultry markets in Lanzhou, northwest China, which poses a potential risk for T. gondii infection in humans and other animals in this region. This is the first seroprevalence study of T. gondii infection in domestic birds in this region.

Prevalence and determinants of metabolic syndrome among adults in a rural area of Northwest China.

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Yaling Zhao

Full Text Available To evaluate the prevalence and determinants of metabolic syndrome (MetS among adults in a rural area of Northwest China.A population-based cross-sectional study was conducted in 2010 among adults aged 18 to 80 years in rural areas of Hanzhong, in Northwest China. Interview, physical and clinical examinations, and fasting blood glucose and lipid measurements were completed for 2990 adults. The definitions of MetS proposed by the Third Report of the National Cholesterol Education Program Expert Panel (Adults Treatment Panel III, ATP III and the International Diabetes Federation (IDF, and the modified ATP III definition for Asian population were used and compared. Proportions were adjusted for age and sex.The prevalence of MetS was 7.9%, 10.8% and 15.1% according to ATP III, IDF and modified ATP III criteria, respectively. Agreement between ATP III and IDF criteria and that between ATP III and modified ATP III criteria were moderate (Kappa = 0.52 and 0.64, respectively, whereas agreement between IDF and modified ATP III criteria was good (Kappa = 0.83. The prevalence of MetS increased with age, and was higher in women than in men (10.4% versus 5.4%, 13.6% versus 8.1% and 17.4% versus 12.8%, according to ATP III, IDF and modified ATP III criteria, respectively. The most common MetS component was high blood pressure. Having family history of hypertension, lack of physical activity, high economical level, overweight and obesity were positively associated with MetS.MetS is prevalent among rural adults in Northwest China and high blood pressure is the most common MetS component. Prevention and treatment of hypertension and MetS should be a public health priority to reduce cardiovascular diseases in rural areas of Northwest China. More attention should be given to the elderly, women, people with family history of hypertension and obese people who are at high risk of MetS.

Progress and prospects of climate change impacts on hydrology in the arid region of northwest China.

Science.gov (United States)

Chen, Yaning; Li, Zhi; Fan, Yuting; Wang, Huaijun; Deng, Haijun

2015-05-01

The arid region of Northwest China, located in the central Asia, responds sensitively to global climate change. Based on the newest research results, this paper analyzes the impacts of climate change on hydrology and the water cycle in the arid region of Northwest China. The analysis results show that: (1) In the northwest arid region, temperature and precipitation experienced "sharply" increasing in the past 50 years. The precipitation trend changed in 1987, and since then has been in a state of high volatility, during the 21st century, the increasing rate of precipitation was diminished. Temperature experienced a "sharply" increase in 1997; however, this sharp increasing trend has turned to an apparent hiatus since the 21st century. The dramatic rise in winter temperatures in the northwest arid region is an important reason for the rise in the average annual temperature, and substantial increases in extreme winter minimum temperature play an important role in the rising average winter temperature; (2) There was a significant turning point in the change of pan evaporation in the northwest arid area in 1993, i.e., in which a significant decline reversed to a significant upward trend. In the 21st century, the negative effects of global warming and increasing levels of evaporation on the ecology of the northwest arid region have been highlighted; (3) Glacier change has a significant impact on hydrology in the northwest arid area, and glacier inflection points have appeared in some rivers. The melting water supply of the Tarim River Basin possesses a large portion of water supplies (about 50%). In the future, the amount of surface water will probably remain at a high state of fluctuation. Copyright © 2015 Elsevier Inc. All rights reserved.

Projected land use changes impacts on water yields in the karst mountain areas of China

Science.gov (United States)

Lang, Yanqing; Song, Wei; Deng, Xiangzheng

2018-04-01

Human-induced land use changes over short time scales have significant impacts on water yield, especially in China because of the rapid social economic development. As the biggest developing country of the world, China's economy is expected to continuously grow with a high speed in the next few decades. Therefore, what kind of land use changes will occur in the future in China? How these changes will influence the water yields? To address this issue, we assessed the water yields in the karst mountain area of China during the periods of 1990-2010 and 2010-2030 by coupling an Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) model and a Conversion of Land Use and its Effects (CLUE) model. Three different land use scenarios i.e. natural growth, economic development, and ecological protection, were developed in 2030 using the CLUE model. It was concluded that, given land use changes between 1990 and 2010, total water yields in the karst mountain area are characterized by a trend towards fluctuating reduction. However, total water yields of 2030 in the economic development scenario revealed an increase of 1.25% compared to the actual water yields in 2010. The economy development in karst mountain areas of China in the future has a slight positive influence on water yields.

Genetic variation in yield and chemical composition of wide range of sorghum accessions grown in north-west China

NARCIS (Netherlands)

Wang, J.S.; Wang, M.L.; Spiertz, J.H.J.; Liu, Z.; Han, L.; Xie, G.H.

2013-01-01

Sorghum can be grown on marginal and waste lands as a versatile feedstock for biofuel production in the vast areas of north-west China. Fifty-six sorghum accessions were grown in 2009 at the experimental station of Xinjiang Agricultural University, located at Urumchi, Xinjiang, China. A total of 31

Groundwater quota versus tiered groundwater pricing : two cases of groundwater management in north-west China

NARCIS (Netherlands)

Aarnoudse, Eefje; Qu, Wei; Bluemling, B.; Herzfeld, Thomas

2017-01-01

Difficulties in monitoring groundwater extraction cause groundwater regulations to fail worldwide. In two counties in north-west China local water authorities have installed smart card machines to monitor and regulate farmers’ groundwater use. Data from a household survey and in-depth interviews are

Mesozoic and Cenozoic uplift and exhumation of the Bogda Mountain, NW China: Evidence from apatite fission track analysis

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Wenhao Tang

2015-07-01

Full Text Available Apatite fission track (AFT analysis on samples collected from a Paleozoic series is used to constrain the cooling history of the Bogda Mountain, northwest China. AFT ages range from 136.2 to 85.6 Ma and are younger than rock depositional ages and the mean confined track lengths (11.0–13.2 μm mostly showing unimodal distribution are shorten, indicating significant track-annealing. Thermal histories modeling based on the distribution of fission-track lengths combined with the regional geological data show that two rapid cooling phases occurred in the latest Jurassic–early Cretaceous and the Oligocene–Miocene. Those new data together with previous published data show that the AFT ages become younger from the southwest to northeast in the western Bogda Mountain and its adjacent areas. The fission-track ages of the southwest area are relatively older (>100 Ma, recording the earlier rapid uplift phase during the late Jurassic–Cretaceous, while the ages in the north piedmont of the Bogda Mountain (namely the northeast part are younger (<60 Ma, mainly reflecting the later rapid uplift phase in the Oligocene–Miocene. The trend of younger AFT ages towards the northeast might be explained by post-Cretaceous large-scale crustal tilting towards the southwest. In the thrust fault-dominated northern limbs of the Bogda Mountain, AFT ages reveal a discontinuous pattern with age-jumps across the major fault zones, showing a possible strata tilting across each thrust faults due to the thrust ramps during the Cenozoic. The two rapid uplift stages might be related to the accretion and collision in the southern margin of the Asian continent during the late Jurassic and late Cenozoic, respectively.

Advances on application of remote sensing technology to uranium prospecting in northwest of China

International Nuclear Information System (INIS)

Ye Fawang; Liu Dechang; Zhao Yingjun; Zhang Jielin; Fang Maolong

2012-01-01

Some advances on application of remote sensing technology to uranium prospecting in northwest of China since 21st century are presented in this paper. They included: (1) application of ETM multi-spectral remote sensing technology to identify the sandstone-type uranium ore-controlling structure in north of Ordos Basin and investigate the uranium metallogenetic geological conditions in Qiangtang Basin, Tibet, (2) application of ASTER multi-spectral and QuickBird high spatial resolution remote sensing technology to extract and analyze the oil-gas reduced alteration in Bashibulake uranium ore district, Xinjiang, (3) discovery of Salamubulake uranium metallogenetic belt in Keping, Xinjiang, using ASTER multi-spectral, QuickBird high spatial resolution, and CASI/SASI airborne hyper-spectral remote sensing comprehensively, and (4) application of CASI/SASI airborne hyper-spectral remote sensing technology to extract volcanicrock type uranium mineralization alteration in Baiyanghe area, Xinjiang. These application advances show the good application effects of remote sensing technology to uranium exploration in northwest of China, which provides important references for making further uranium prospecting using remote sensing technology. (authors)

Two new species of Neoperla (Plecoptera, Perlidae) from Dabie Mountains of China.

Science.gov (United States)

Li, Wei-Hai; Zhang, Sheng-Quan

2014-01-01

Two new species of the stonefly genus Neoperla, N. nigromarginata sp. n. and N. similiflavescens sp. n., are described from Dabie Mountains of Central China in the Liankangshan National Nature Reserve. The new species are compared with related congeners.

Influence of climate change and human activity on water resources in arid region of Northwest China: An overview

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Yu-Jie Wang

2017-12-01

Full Text Available This study reviews the latest progress in research on climate change and water resources in the arid region of Northwest China, analyzes the cause of water resource changes within the region from the perspective of climate change and human activities, and summarizes future likely changes in water resources and associated adaptation strategies. The research shows that the climate in the region has experienced warming and wetting with the most significant warming in winter and the highest increase in summer precipitation since 1961. Areas with the most significant warming trends include the Qaidam Basin, the Yili River Valley, and Tacheng. Spatially, the increasing trend in precipitation becomes increasingly significant from the southeast to the northwest, and northern Xinjiang experienced the highest increase. Studies have shown a decrease in headwater of Shiyang River because runoff is mainly based on precipitation which shows a decrease trend. But an increase in western rivers was observed such as Tarim River and Shule River as well as Heihe River due to rapid glacier shrinkage and snowmelt as well as precipitation increase in mountain area. Meanwhile unreasonable human activities resulted in decrease of runoff in the middle and lower reaches of Haihe River, Shiyang River and Kaidu River. Finally, recommendations for future studies are suggested that include characteristics of changes in extreme weather events and their impacts on water resources, projections of future climate and water resource changes, climate change attribution, the selection of adaptation strategies relating to climate change and social economic activities, and use of scientific methods to quantitatively determine water resource allocation.

Modeling Urban Spatial Growth in Mountainous Regions of Western China

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Guoping Huang

2017-08-01

Full Text Available The scale and speed of urbanization in the mountainous regions of western China have received little attention from researchers. These cities are facing rapid population growth and severe environmental degradation. This study analyzed historical urban growth trends in this mountainous region to better understand the interaction between the spatial growth pattern and the mountainous topography. Three major factors—slope, accessibility, and land use type—were studied in light of their relationships with urban spatial growth. With the analysis of historical data as the basis, a conceptual urban spatial growth model was devised. In this model, slope, accessibility, and land use type together create resistance to urban growth, while accessibility controls the sequence of urban development. The model was tested and evaluated using historical data. It serves as a potential tool for planners to envision and assess future urban growth scenarios and their potential environmental impacts to make informed decisions.

Global Warming: The Instability of Desert Climate is Enhancing in the Northwest Area in China: A Case Study in the Desert Area in Northwestern China

OpenAIRE

Zhao-Feng Chang; Shu-Juan Zhu; Fu-Gui Han; Sheng-Nnian Zhong; Qiang-Qiang Wang; Jian-Hui Zhang

2013-01-01

To disclose the relation between the sandstorms change and the temperature changes, a case study in the desert area in northwestern china is investigated. The results showed that: the instability of climate in Minqin desert area is enhancing in the arid desert region in northwest China. Mainly as follows: Variation the annual extreme maximum temperature increasing. Variation of extreme minimum temperature also an increasing trend. Average visibility of sandstorms significantly reduced and the...

Evaluation of Climate Change Impacts on Wetland Vegetation in the Dunhuang Yangguan National Nature Reserve in Northwest China Using Landsat Derived NDVI

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Feifei Pan

2018-05-01

Full Text Available Based on 541 Landsat images between 1988 and 2016, the normalized difference vegetation indices (NDVIs of the wetland vegetation at Xitugou (XTG and Wowachi (WWC inside the Dunhuang Yangguan National Nature Reserve (YNNR in northwest China were calculated for assessing the impacts of climate change on wetland vegetation in the YNNR. It was found that the wetland vegetation at the XTG and WWC had both shown a significant increasing trend in the past 20–30 years and the increase in both the annual mean temperature and annual peak snow depth over the Altun Mountains led to the increase of the wetland vegetation. The influence of the local precipitation on the XTG wetland vegetation was greater than on the WWC wetland vegetation, which demonstrates that in extremely arid regions, the major constraint to the wetland vegetation is the availability of water in soils, which is greatly related to the surface water detention and discharge of groundwater. At both XTG and WWC, the snowmelt from the Altun Mountains is the main contributor to the groundwater discharge, while the local precipitation plays a lesser role in influencing the wetland vegetation at the WWC than at the XTG, because the wetland vegetation grows on a relatively flat terrain at the WWC, while it grows on a stream channel at the XTG.

Phylogeographic patterns of the desert poplar in Northwest China shaped by both geology and climatic oscillations.

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Zeng, Yan-Fei; Zhang, Jian-Guo; Abuduhamiti, Bawerjan; Wang, Wen-Ting; Jia, Zhi-Qing

2018-05-25

The effects of historical geology and climatic events on the evolution of plants around the Qinghai-Tibetan Plateau region have been at the center of debate for years. To identify the influence of the uplift of the Tianshan Mountains and/or climatic oscillations on the evolution of plants in arid northwest China, we investigated the phylogeography of the Euphrates poplar (Populus euphratica) using chloroplast DNA (cpDNA) sequences and nuclear microsatellites, and estimated its historical distribution using Ecological Niche Modeling (ENM). We found that the Euphrates poplar differed from another desert poplar, P. pruinosa, in both nuclear and chloroplast DNA. The low clonal diversity in both populations reflected the low regeneration rate by seed/seedlings in many locations. Both cpDNA and nuclear markers demonstrated a clear divergence between the Euphrates poplar populations from northern and southern Xinjiang regions. The divergence time was estimated to be early Pleistocene based on cpDNA, and late Pleistocene using an Approximate Bayesian Computation analysis based on microsatellites. Estimated gene flow was low between these two regions, and the limited gene flow occurred mainly via dispersal from eastern regions. ENM analysis supported a wider distribution of the Euphrates poplar at 3 Ma, but a more constricted distribution during both the glacial period and the interglacial period. These results indicate that the deformation of the Tianshan Mountains has impeded gene flow of the Euphrates poplar populations from northern and southern Xinjiang, and the distribution constriction due to climatic oscillations further accelerated the divergence of populations from these regions. To protect the desert poplars, more effort is needed to encourage seed germination and seedling establishment, and to conserve endemic gene resources in the northern Xinjiang region.

The Local Residents’ Concerns about Environmental Issues in Northwest China

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Fanus A. Aregay

2016-03-01

Full Text Available This paper analyzes public awareness and perception about current issues of environmental and water resources in China in comparison to the socio-economic issues. The ranking, Likert scale, and ordered logit analysis were applied to data from 1773 sample residents in northwest China. The results show that the residents rank the degradation of the ecological environment and water resources as the most important issue, and education, political involvement, gender, employment, and residential location play significant roles in explaining the observed differences in concern. Of the possible environmental and water resource restoration policies, residents ranked water quantity and quality, agricultural and industrial water use, erosion control, vegetation restoration, wildlife habitat, animal brooding and migration services, biodiversity landscape, and eco-tourism from one to nine in order of importance, respectively. The results are relevant for policymaking and imply that environmental restoration is a high public demand. Welfare gains from investments in it would be higher or equal to gains from other socio-economic and livelihood activities. Thus, public policies must emphasize restoring and maintaining a sustainable ecological environment.

Two new species of Amphinemura (Plecoptera: Nemouridae) from the Gaoligong Mountains of Yunnan, China.

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Li, Weihai; Wang, Ying; Yang, Ding

2016-11-29

Two new species of the nemourid genus Amphinemura, A. apicilobata sp. nov. and A. bimaculata sp. nov. are described from the Gaoligong Mountains of Yunnan Province, China. The new species are compared with related congeners.

Assessing the Sustainability of the Built Environment in Mountainous Rural Villages in Southwest China

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Li Wan

2016-02-01

Full Text Available Mountainous rural areas such as those in southwest China are developing rapidly. This requires scientific understanding and a framework for assessing the sustainability of the built environment that is suitable to such areas. At present, no such framework exists. This lack of assessment options has contributed to the unsustainable development of these areas, which has caused a series of environmental, social, and economic problems. This article analyzes existing assessment frameworks, reviews the theory on sustainable rural development as it applies to rural southwest China, and proposes a new assessment framework that is more suitable to this region and others like it. This framework is based on a sustainable development model for rural areas that emphasizes endogenous development; addresses the environmental, social, and economic dimensions of sustainability; and takes the natural and social conditions of mountainous rural areas into account. Our study tested its applicability to rural southwest China and its sensitivity to local conditions and found them to be better than those of existing assessment frameworks.

Land degradation mapping based on hyperion data in desertification region of northwest China

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Cheng, Penggen; Wu, Jian; Ouyang, Ping; He, Ting

2008-10-01

Desertification is an alarming sign of land degradation in Henshan county of northwest china. Due to the considerable costs of detailed ground surveys of this phenomenon, remote sensing is an appropriate alternative for analyzing and evaluating the risks of the expansion of land degradation. Degradation features can be detected directly or indirectly by using image data. In this paper, based on the Hyperion images of Hengshan desertification region of northwest china, a new algorithm aimed at land degradation mapping, called Land Degradation Index (LDI), was put forward. This new algorithm is based on the classified process. We applied the linear spectral unmixing algorithm with the training samples derived from the formerly classified process so as to find out new endmembers in the RMS error imagine. After that, using neutral net mapping with new training samples, the classified result was gained. In addition, after applying mask processing, the soils were grouped to 3 types (Kappa =0.90): highly degraded soils, moderately degraded soils and slightly degraded soils. By analyzing 3 mapping methods: mixture-classification, the spectral angle mapper and mixturetuned matched filtering, the results suggest that the mixture-classification has the higher accuracy (Kappa=0.7075) than the spectral angle mapper (Kappa=0.5418) and the mixture-tuned matched filter (Kappa=0.6039). As a result, the mixture-classification is selected to carry out Land Degradation Index analysis.

Geology of the Saddle Mountains between Sentinel Gap and 119030' longitude

International Nuclear Information System (INIS)

Reidel, S.P.

1978-09-01

Members and flows of the Grande Ronde, Wanapum, and Saddle Mountains basalts of the Columbia River Basalt Group were mapped in the Saddle Mountains between Sentinel Gap and the eastern edge of Smyrna Bench. The Grande Ronde Basalt consists of the Schwana (low-MgO) and Sentinel Bluffs (high-MgO) members (informal names). The Wanapum Basalt consists of the aphyric and phyric units of the Frenchman Springs Member, the Roza-Like Member, and the Priest Rapids Member. The Saddle Mountains Basalt consists of the Wahluke, Huntzinger, Pomona, Mattawa, and Elephant Mountain basalts. The Wanapum and Saddle Mountains basalts are unevenly distributed across the Saddle Mountains. The Wanapum Basalt thins from south to north and across a northwest-southeast-trending axis at the west end of Smyrna Bench. The Priest Rapids, Roza-Like, and aphyric Frenchman Springs units are locally missing across this zone. The Saddle Mountains basalt has a more irregular distribution and, within an area between Sentinel Gap and Smyrna Bench, is devoid of the basalt. The Wahluke, Huntzinger, and Mattawa flows are locally present, but the Pomona is restricted to the southern flank west of Smyrna Bench, and the Elephant Mountain Basalt only occurs on the flanks and in three structurally controlled basins on the northwest side. The structure of the Saddle Mountains is dominated by an east-west trend and, to a lesser degree, controlled by a northwest-southeast and northeast-southwest trend. The geomorphological expression of the Saddle Mountains results from the east-west fold set and the Saddle Mountains fault along the north side. The oldest structures follow the northwest-southeast trend. The distribution of the flows, combined with the structural features, indicates a complex geologic history for the Saddel Mountains

Establishment and assessment of cataract surgery in Day-care Unit at northwest of China

OpenAIRE

Xiu-Li Zhang; Xing Yang; Juan-Juan Yang; Bao-Jian Yan; Jing-Ming Li; Cheng Pei; Li Qin

2018-01-01

AIM: To describe the protocol and economic cost of the Day-care Unit cataract surgery procedure in northwest of China.METHODS: Patients who received phacoemulcification and intraocular lens implantation in both Day-care Unit and regular Unit were recruited from January 2016 to December 2016. The baseline data and average cost were recorded and analyzed. Furthermore, satisfaction questionnaire of patients were collected.RESULTS: Patients with Day-care Unit showed shorter registration duration,...

A population-based study examining hepatitis B virus infection and immunization rates in Northwest China.

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Zhaohua Ji

Full Text Available BACKGROUND AND AIM: Current baseline data regarding the prevalence of hepatitis B virus (HBV infections and the immune status in hyperendemic areas is necessary in evaluating the effectiveness of ongoing HBV prevention and control programs in northwest China. This study aims to determine the prevalence of chronic HBV infections, past exposure rates, and immune response profiles in Wuwei City, northwest China in 2010. METHODS: Cross-sectional household survey representative of the Wuwei City population. 28,579 participants were interviewed in the seroepidemiological survey ≥1 year of age. House to house screening was conducted using a standard questionnaire. All serum samples were screened by enzyme-linked immunoassays for the presence of hepatitis B surface antigen, antibodies against HBV surface antigen, and antibodies to the hepatitis B core antigen. RESULTS: Among individuals ≥1 year of age, 7.2% (95%CI: 6.3-8.1% had chronic HBV infections, 43.9% (CI: 40.4-47.4% had been exposed to HBV, and 23.49% (CI: 21.6-25.3% had vaccine-induced immunity. Multi-factor weighted logistic regression analysis showed that having household contact with HBV carriers (OR = 2.6, 95%CI: 2.3-3.0 and beauty treatments in public places (OR = 1.2, 95%CI: 1.1-1.3 were the risk factors of HBV infection in whole population. Having household contact with HBV carriers (OR = 3.8, 95% CI: 2.2-6.5 and lack of hepatitis vaccination (OR = 2.0, 95% CI: 1.4-3.3 were the risk factors for HBV infection in children aged 1-14 years. CONCLUSIONS: Hepatitis B infection remains a serious public health problem in northwest China. Having household contact with HBV carriers and beauty treatments in public places represented HBV infection risk factors. Hepatitis B vaccine immunization strategies need further improvement, particularly by targeting the immunization of rural migrant workers.

White rice consumption and risk of esophageal cancer in Xinjiang Uyghur Autonomous Region, northwest China: a case-control study

OpenAIRE

Tang, Li; Xu, Fenglian; Zhang, Taotao; Lei, Jun; Binns, Colin W.; Lee, Andy H.

2015-01-01

This study investigated the association between white rice consumption and the risk of esophageal cancer in remote northwest China, where the cancer incidence is known to be high. A case-control study was conducted during 2008?2009 in Urumqi and Shihezi, Xinjiang Uyghur Autonomous Region of China. Participants were 359 incident esophageal cancer patients and 380 hospital-based controls. Information on habitual white rice consumption was obtained by personal interview using a validated semi-qu...

Spatiotemporal changes in vegetation net primary productivity in the arid region of Northwest China, 2001 to 2012

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Li, Zhen; Pan, Jinghu

2018-03-01

Net primary productivity (NPP) is recognized as an important index of ecosystem conditions and a key variable of the terrestrial carbon cycle. It also represents the comprehensive effects of climate change and anthropogenic activity on terrestrial vegetation. In this study, the temporal-spatial pattern of NPP for the period 2001-2012 was analyzed using a remote sensing-based carbon model (i.e., the Carnegie-Ames-Stanford Approach, CASA) in addition to other methods, such as linear trend analysis, standard deviation, and the Hurst index. Temporally, NPP showed a significant increasing trend for the arid region of Northwest China (ARNC), with an annual increase of 2.327 g C. Maximum and minimum productivity values appeared in July and December, respectively. Spatially, the NPP was relatively stable in the temperate and warm-temperate desert regions of Northwest China, while temporally, it showed an increasing trend. However, some attention should be given to the northwestern warm-temperate desert region, where there is severe continuous degradation and only a slight improvement trend.

Multi-tracer investigation of river and groundwater interactions: a case study in Nalenggele River basin, northwest China

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Xu, Wei; Su, Xiaosi; Dai, Zhenxue; Yang, Fengtian; Zhu, Pucheng; Huang, Yong

2017-11-01

Environmental tracers (such as major ions, stable and radiogenic isotopes, and heat) monitored in natural waters provide valuable information for understanding the processes of river-groundwater interactions in arid areas. An integrated framework is presented for interpreting multi-tracer data (major ions, stable isotopes (2H, 18O), the radioactive isotope 222Rn, and heat) for delineating the river-groundwater interactions in Nalenggele River basin, northwest China. Qualitative and quantitative analyses were undertaken to estimate the bidirectional water exchange associated with small-scale interactions between groundwater and surface water. Along the river stretch, groundwater and river water exchange readily. From the high mountain zone to the alluvial fan, groundwater discharge to the river is detected by tracer methods and end-member mixing models, but the river has also been identified as a losing river using discharge measurements, i.e. discharge is bidirectional. On the delta-front of the alluvial fan and in the alluvial plain, in the downstream area, the characteristics of total dissolved solids values, 222Rn concentrations and δ18O values in the surface water, and patterns derived from a heat-tracing method, indicate that groundwater discharges into the river. With the environmental tracers, the processes of river-groundwater interaction have been identified in detail for better understanding of overall hydrogeological processes and of the impacts on water allocation policies.

Long-term dynamic characterization of aeolian desertification in northwest Shanxi, China.

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Xue, Zhanjin; Qin, Zuodong; Cheng, Fangqin; Ding, Guangwei; Li, Hongjian

2017-07-01

Northwest Shanxi is located on the farming-pastoral ecotone of northern China, where aeolian desertification is one of the most serious environmental and socioeconomic issues. The remote sensing image and geostatistical approach were implemented to estimate aeolian desertified land (ADL) dynamic variations from 1975 to 2015. Results showed that the ADL covered 11,685.21 km 2 (82.29%) of the study area in 2015, the majority of which was classified as a light or moderate degree. The area of ADL gradually expanded at an increasing rate of 87.37 km 2 a -1 during the 1975-2000 periods. More specifically, the area of ADL has increased by 1259.23 km 2 from 1975 to 1990 and by 924.96 km 2 from 1990 to 2000, respectively. In contrast, spatial transfer of ADL areas has dwindled by 2365.85 km 2 with a net decrease of 157.72 km 2 a -1 , and the mitigated areas of aeolian desertification were 10,602.24 km 2 between 2000 and 2015. During the past 40 years, the gravity center of ADL migrated to southeast until 2000 and moved northwest in 2000-2015. From 1975 to 2000, the migration distance of severe ADL was the largest, migrated toward the northwest by 19.03 km in 1975-1990 and by 20.16 km in 1990-2000, respectively. From 2000 to 2015, the migration distance of light ADL was the largest, 27.54 km migrated to the northwest. Aeolian desertification rapidly expanded from 1975 to 2000 under the combination of climate change and intensive human activities. Since the year of 2000, ecological engineering strategy initiated by the governments has been the dominant contributor to the aeolian desertification severity reversal. Aeolian desertification prevention is a complicated process. Both the central and local government should play a critical role in the rehabilitation of ADL in the long term.

Early to Middle Jurassic tectonic evolution of the Bogda Mountains, Northwest China: Evidence from sedimentology and detrital zircon geochronology

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Ji, Hongjie; Tao, Huifei; Wang, Qi; Qiu, Zhen; Ma, Dongxu; Qiu, Junli; Liao, Peng

2018-03-01

The Bogda Mountains, as an important intracontinental orogenic belt, are situated in the southern part of the Central Asian Orogenic Belt (CAOB), and are a key area for understanding the Mesozoic evolution of the CAOB. However, the tectonic evolution of the Bogda Mountains remains controversial during the Mesozoic Era, especially the Early to Middle Jurassic Periods. The successive Lower to Middle Jurassic strata are well preserved and exposed along the northern flank of the Western Bogda Mountains and record the uplift processes of the Bogda Mountains. In this study, we analysed sedimentary facies combined with detrital zircon U-Pb geochronology at five sections of Lower to Middle Jurassic strata to detect the tectonic evolution and changes of provenance in the Bogda area. During Early to Middle Jurassic times, the fluvial, deltaic and lacustrine environments dominated in the western section of the Bogda area. The existence of Early Triassic peak age indicates that the Bogda Mountains did not experience uplift during the period of early Badaowan Formation deposition. The Early Triassic to Late Permian granitoid plutons and Carboniferous volcanic rocks from the Barkol and Santanghu areas were the main provenances. The significant change in the U-Pb age spectrum implies that the Eastern Bogda Mountains initiated uplift in the period of late Badaowan Formation deposition, and the Eastern Junggar Basin and the Turpan-Hami Basin were partially partitioned. The Eastern Bogda Mountains gradually became the major provenance. From the period of early Sangonghe to early Toutunhe Formations deposition, the provenance of the sediments and basin-range frame were similar to that of late Badaowan. However, the Eastern Bogda Mountains suffered intermittent uplift three times, and successive denudation. The uplifts respectively happened in early Sangonghe, late Sangonghe to early Xishanyao, and late Xishanyao to early Toutunhe. During the deposition stage of Toutunhe Formation, a

Effect of permafrost properties on gas hydrate petroleum system in the Qilian Mountains, Qinghai, Northwest China.

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Wang, Pingkang; Zhang, Xuhui; Zhu, Youhai; Li, Bing; Huang, Xia; Pang, Shouji; Zhang, Shuai; Lu, Cheng; Xiao, Rui

2014-12-01

The gas hydrate petroleum system in the permafrost of the Qilian Mountains, which exists as an epigenetic hydrocarbon reservoir above a deep-seated hydrocarbon reservoir, has been dynamic since the end of the Late Pleistocene because of climate change. The permafrost limits the occurrence of gas hydrate reservoirs by changing the pressure-temperature (P-T) conditions, and it affects the migration of the underlying hydrocarbon gas because of its strong sealing ability. In this study, we reconstructed the permafrost structure of the Qilian Mountains using a combination of methods and measured methane permeability in ice-bearing sediment permafrost. A relationship between the ice saturation of permafrost and methane permeability was established, which permitted the quantitative evaluation of the sealing ability of permafrost with regard to methane migration. The test results showed that when ice saturation is >80%, methane gas can be completely sealed within the permafrost. Based on the permafrost properties and genesis of shallow gas, we suggest that a shallow "gas pool" occurred in the gas hydrate petroleum system in the Qilian Mountains. Its formation was related to a metastable gas hydrate reservoir controlled by the P-T conditions, sealing ability of the permafrost, fault system, and climatic warming. From an energy perspective, the increasing volume of the gas pool means that it will likely become a shallow gas resource available for exploitation; however, for the environment, the gas pool is an underground "time bomb" that is a potential source of greenhouse gas.

Planning for Regional Water Resources in Northwest China Using a Dynamic Simulation Model

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Chen, C.; Kalra, A.; Ahmad, S.

2014-12-01

Problem of water scarcity is prominent in northwest China due to its typical desert climate. Exceedence of sustainable yield of groundwater resources has resulted in groundwater depletion, which has raised a series of issues such as drying wells, increasing pumping costs and environmental damage. With a rapid agricultural and economic development, population increase has added extra stress on available water resources by increasing municipal, agricultural and industrial demands. This necessitates efficient water resources management strategies with better understanding of the causes of water stress and options for sustainable development of economy and management of environment. This study focuses on simulating the water supply and demand, under the influence of changing climate, for Shanshan County, located in northwest of China. A dynamic simulation model is developed using the modeling tool Stella for monthly water balance for the period ranging from 2000-2030. Different future water demand and supply scenarios are developed to represent: (1) base scenario- with current practices; (2) change of the primary water source; (3) improvement of irrigation efficiency; (4) reduction of irrigation area; and (5) reduction of industrial water demand. The results indicate that besides growing demand, the low water use efficiency and low level of water reuse are the primary concerns for water scarcity. Groundwater recharge and abstraction could be balanced by 2030, by reducing industrial demand by 50% and using high efficiency irrigation for agriculture. The model provided a better understanding of the effect of different policies and can help in identifying water resources management strategies.

NPP estimation and seasonal change research of Gansu province in northwest China

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Han, Tao; Wang, Dawei; Hao, Xiaocui; Jiang, Youyan

2018-03-01

Based on GIS and remote sensing technology, this paper estimates the NPP of the 2015 year-round and every season of Gansu province in northwest China by using the CASA(Carnegie Ames Stanford Approach) light energy utilization model. The result shows that the total annual NPP of Gansu province gradually decline from southeast to northwest in the space, which is in accordance with the water and heat condition in Gansu province. The results show that the summer NPP in Gansu Province is the maximum in each season. The maximum value of summer NPP in Gansu Province reached 695 (gCm-2•season-1), and the maximum value was 473 in spring, and 288 in the autumn, and the NPP in the winter in Gansu province were under 60. The fluctuation range of NPP value is large, this is due to the diversity of ecosystem types in Gansu province, including desert, grassland, farmland and forest, among them, the grassland area is the largest, and the grassland type is very diverse, the grassland coverage is obviously different, especially the low coverage grassland growth is affected by precipitation and temperature and other meteorological factors obviously.

Ecosystem Evapotranspiration as a Response to Climate and Vegetation Coverage Changes in Northwest Yunnan, China.

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Yang, Hao; Luo, Peng; Wang, Jun; Mou, Chengxiang; Mo, Li; Wang, Zhiyuan; Fu, Yao; Lin, Honghui; Yang, Yongping; Bhatta, Laxmi Dutt

2015-01-01

Climate and human-driven changes play an important role in regional droughts. Northwest Yunnan Province is a key region for biodiversity conservation in China, and it has experienced severe droughts since the beginning of this century; however, the extent of the contributions from climate and human-driven changes remains unclear. We calculated the ecosystem evapotranspiration (ET) and water yield (WY) of northwest Yunnan Province, China from 2001 to 2013 using meteorological and remote sensing observation data and a Surface Energy Balance System (SEBS) model. Multivariate regression analyses were used to differentiate the contribution of climate and vegetation coverage to ET. The results showed that the annual average vegetation coverage significantly increased over time with a mean of 0.69 in spite of the precipitation fluctuation. Afforestation/reforestation and other management efforts attributed to vegetation coverage increase in NW Yunnan. Both ET and WY considerably fluctuated with the climate factors, which ranged from 623.29 mm to 893.8 mm and -51.88 mm to 384.40 mm over the time period. Spatially, ET in the southeast of NW Yunnan (mainly in Lijiang) increased significantly, which was in line with the spatial trend of vegetation coverage. Multivariate linear regression analysis indicated that climatic factors accounted for 85.18% of the ET variation, while vegetation coverage explained 14.82%. On the other hand, precipitation accounted for 67.5% of the WY. We conclude that the continuous droughts in northwest Yunnan were primarily climatically driven; however, man-made land cover and vegetation changes also increased the vulnerability of local populations to drought. Because of the high proportion of the water yield consumed for subsistence and poor infrastructure for water management, local populations have been highly vulnerable to climate drought conditions. We suggest that conservation of native vegetation and development of water

Soya and isoflavone intakes associated with reduced risk of oesophageal cancer in north-west China.

Science.gov (United States)

Tang, Li; Lee, Andy H; Xu, Fenglian; Zhang, Taotao; Lei, Jun; Binns, Colin W

2015-01-01

To ascertain the association between soya consumption, isoflavone intakes and oesophageal cancer risk in remote north-west China, where the incidence of oesophageal cancer is known to be high. Case-control study. Information on habitual consumption of soya foods and soya milk was obtained by personal interview. The intakes of isoflavones were then estimated using the US Department of Agriculture nutrient database. Logistic regression analyses were performed to assess the association between soya consumption, isoflavone intakes and oesophageal cancer risk. Urumqi and Shihezi, Xinjiang Uyghur Autonomous Region, China. Participants were 359 incident oesophageal cancer patients and 380 hospital-based controls. The oesophageal cancer patients consumed significantly less (P soya foods (mean 57·2 (sd 119·0) g/d) and soya milk (mean 18·8 (sd 51·7) ml/d) than the controls (mean 93·3 (sd 121·5) g/d and mean 35·7 (sd 73·0) ml/d). Logistic regression analyses showed an inverse association between intake of soya products and the risk of oesophageal cancer. The adjusted odds were OR = 0·33 (95 % CI 0·22, 0·49) and OR = 0·48 (95 % CI 0·31, 0·74) for consuming at least 97 g of soya foods and 60 ml of soya milk daily (the highest tertiles of consumption), respectively, relative to the lowest tertiles of consumption. Similarly, inverse associations with apparent dose-response relationships were found between isoflavone intakes and oesophageal cancer risk. Habitual consumption of soya products appears to be associated with reduced risk of oesophageal cancer in north-west China.

A Picea crassifolia Tree-Ring Width-Based Temperature Reconstruction for the Mt. Dongda Region, Northwest China, and Its Relationship to Large-Scale Climate Forcing.

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Yu Liu

Full Text Available The historical May-October mean temperature since 1831 was reconstructed based on tree-ring width of Qinghai spruce (Picea crassifolia Kom. collected on Mt. Dongda, North of the Hexi Corridor in Northwest China. The regression model explained 46.6% of the variance of the instrumentally observed temperature. The cold periods in the reconstruction were 1831-1889, 1894-1901, 1908-1934 and 1950-1952, and the warm periods were 1890-1893, 1902-1907, 1935-1949 and 1953-2011. During the instrumental period (1951-2011, an obvious warming trend appeared in the last twenty years. The reconstruction displayed similar patterns to a temperature reconstruction from the east-central Tibetan Plateau at the inter-decadal timescale, indicating that the temperature reconstruction in this study was a reliable proxy for Northwest China. It was also found that the reconstruction series had good consistency with the Northern Hemisphere temperature at a decadal timescale. Multi-taper method spectral analysis detected some low- and high-frequency cycles (2.3-2.4-year, 2.8-year, 3.4-3.6-year, 5.0-year, 9.9-year and 27.0-year. Combining these cycles, the relationship of the low-frequency change with the Pacific Decadal Oscillation (PDO, North Atlantic Oscillation (NAO and Southern Oscillation (SO suggested that the reconstructed temperature variations may be related to large-scale atmospheric-oceanic variations. Major volcanic eruptions were partly reflected in the reconstructed temperatures after high-pass filtering; these events promoted anomalous cooling in this region. The results of this study not only provide new information for assessing the long-term temperature changes in the Hexi Corridor of Northwest China, but also further demonstrate the effects of large-scale atmospheric-oceanic circulation on climate change in Northwest China.

Pleistocene climate change and the origin of two desert plant species, Pugionium cornutum and Pugionium dolabratum (Brassicaceae), in northwest China.

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Wang, Qian; Abbott, Richard J; Yu, Qiu-Shi; Lin, Kao; Liu, Jian-Quan

2013-07-01

Pleistocene climate change has had an important effect in shaping intraspecific genetic variation in many species; however, its role in driving speciation is less clear. We examined the possibility of a Pleistocene origin of the only two representatives of the genus Pugionium (Brassicaceae), Pugionium cornutum and Pugionium dolabratum, which occupy different desert habitats in northwest China. We surveyed sequence variation for internal transcribed spacer (ITS), three chloroplast (cp) DNA fragments, and eight low-copy nuclear genes among individuals sampled from 11 populations of each species across their geographic ranges. One ITS mutation distinguished the two species, whereas mutations in cpDNA and the eight low-copy nuclear gene sequences were not species-specific. Although interspecific divergence varied greatly among nuclear gene sequences, in each case divergence was estimated to have occurred within the Pleistocene when deserts expanded in northwest China. Our findings point to the importance of Pleistocene climate change, in this case an increase in aridity, as a cause of speciation in Pugionium as a result of divergence in different habitats that formed in association with the expansion of deserts in China. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

Five new species of Phintella Strand, 1906 (Araneae, Salticidae from the Wuling Mountains, China

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Yi Huang

2015-07-01

Full Text Available Five new species of Phintella are described from the Wuling Mountains, China: Phintella arcuata sp. n. (male and female, Phintella levii sp. n. (female, Phintella panda sp. n. (female, Phintella pulcherrima sp. n. (male and female, and Phintella wulingensis sp. n. (female. Distribution data, detailed morphological characteristics, and illustrations of body and genital organs are presented.

Plant biodiversity patterns on Helan Mountain, China

Science.gov (United States)

Jiang, Yuan; Kang, Muyi; Zhu, Yuan; Xu, Guangcai

2007-09-01

A case study was conducted to mountainous ecosystems in the east side of Helan Mountain, located in the transitional zone between steppe and desert regions of China, aiming to reveal the influences of four environmental factors on features of plant biodiversity—the spatial pattern of vegetation types, and the variation of α- and β-diversities in vegetation and flora. Field surveys on vegetation and flora and on environmental factors were conducted, and those field data were analyzed through CCA (Canonical Correspondence Analysis), and through Shannon-Weiner index for α-diversity and Sørensen index for β-diversity. The preliminary results are: (1) Ranked in terms of their impacts on spatial patterns of plant biodiversity, the four selected environmental factors would be: elevation > location > slope > exposure. (2) The variation of Shannon-Weiner index along the altitudinal gradient is similar to that of species amount within altitudinal belts spanning 200 m each, which suggests a unimodal relationship between the species richness and the environmental condition with regards to altitudinal factors. Both the Shannon-Weiner index and the species richness within each altitudinal belt reach their maximum at elevation range from about 1700 to 2000 m a.s.l. (3) The altitudinal extent with the highest Shannon-Weiner index is identical to the range, where both the deciduous broad-leaved forest, and the temperate evergreen coniferous and deciduous broad-leaved mixed forest distribute. The altitudinal range from 1700 to 2200 m a.s.l. is the sector with both high level of species richness and diversified vegetation types. (4) The variation of β-diversity along the altitude is consistent with the vegetation vertical zones. According to the Sørensen index between each pair of altitudinal belts, the transition of vegetation spectrum from one zone to another, as from the base horizontal zone, the desert steppe, to the first vertical zone, the mountain open forest and

Quantitative Analysis and Comparison of BMI among Han, Tibetan, and Uygur University Students in Northwest China

OpenAIRE

Jingya, Bai; Ye, He; Jing, Wang; Xi, Huanjiu; Tao, Hai

2013-01-01

Objectives. To fully analyze and compare BMI among Han, Tibetan, and Uygur university students, to discuss the differences in their physical properties and physical health, and thus to provide some theoretical suggestions for the improvement of students’ physical health. Methods. The cross-sectional random cluster sampling was used to investigate 10103 Han, Tibetan, and Uygur university students, aged 20–24 in Northwest China, and their height and weight were measured to calculate BMI. The BM...

Slingram survey at Yucca Mountain on the Nevada Test Site

International Nuclear Information System (INIS)

Flanigan, V.J.

1981-01-01

Electromagnetic (EM) data presented in this report is part of study by the US Geological Survey aimed at evaluating the Miocene and Pliocene Yucca Mountain Member of various units of the Paintbrush Tuff in the vicinity of Yucca Mountain as a possible repository for nuclear wastes. The survey area is located about 97 km northwest of Las Vegas, Nevada on the Nevada Test Site. Data contained in this report were taken along the eastern edge of Yucca Mountain. The specific purpose of this survey was to determine with EM methods, whether or not northwest-trending valleys in the Yucca Mountain area were fault controlled. Fault and fracture zones in the tuff units were expected to have a somewhat higher conductivity than the unfractured tuff. This is due to the greater porosity, clay and moisture content expected in the fault zones than in unfaulted rock. Depending upon a number of factors, such as the conductivity contrast between fault zones and unfaulted rock, and the depth and conductivity of the overburden, it may be possible to recognize fault zones from surface EM measurements. Several EM methods were tested to determine which one gave the best results in this environment. The methods tried included slingram, Turam and VLF (very low frequency). Slingram data proved to be most diagnostic in delineating a mapped fault on the east edge of Yucca Mountain, and hence was used in the survey traverses crossing the northwest valleys cutting into Yucca Mountain

Stoneflies of the genus Neoperla (Plecoptera, Perlidae) from Wuyi Mountain National Nature Reserve, Fujian of China.

Science.gov (United States)

Qin, Xue-Feng; Murányi, Dávid; Wang, Guo-Quan; Li, Wei-Hai

2013-01-01

The species of the genus Neoperla are reviewed from Wuyi Mountain National Nature Reserve located in the Fujian Province of southeastern China, including the description of a new species, Neoperla brevistyla sp. n. The new species is compared to similar taxa. The first records of five Neoperla species, Neoperla henana Li, Wu & Zhang, 2011, Neoperla similiserecta Wang & Li, 2012, Neoperla qingyuanensis Yang & Yang, 1995, Neoperla xuansongae Li & Li, 2013 and Neoperla tuberculata Wu, 1938 are given for the Wuyi Mountain. A provisional key is provided for facilitating the identification of these species.

Impact of Climate Change on Rain-fed Farming and Response Solutions in Semiarid Area of Northwest China

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WANG Hong-li

2015-12-01

Full Text Available The impact of climate change on the agriculture production in semi-arid areas of Northwest, the major drought-resistant technology, the mechanism of increasing grain production were analyzed to explore technical solutions to retort the future climate change, future development of rainfed agriculture, and provide reference for food security. The results showed that the impact of future climate change on crop growth had main three aspects: Firstly, higher temperatures resulted in lower crop yield and quality decline; Secondly, changes in precipitation and precipitation patterns resulted in drought/flooding problems; Thirdly, meteorological disasters caused by extreme weather lead to fluctuations of food production. To adapt or mitigate these adverse effects, increase use efficiency of limited rainfall, optimize soil structure, improve soil fertility, enhance withstanding environmental change ability of crop-soil system, mitigate the impact of future climate change on food production in semi-arid region of Northwest China, the mainly solutions were: (1 Covering gathered precipitation, improve the ability to accumulate soil moisture, change the distribution of soil moisture, regulate the migration and improve the infiltration of precipitation, thus “adjusting water” to adapt to precipitation changes; (2 Optimizing soil structure, physical and chemical properties by soil fertilization, thus “regulating soil” to improve the ability of crop-soil system against to environmental changes, in order to stabilize productivity of rainfed agriculture; (3 Integrate “adjusting water” and “regulating soil” technology, forming technical system of “coordination of water and soil” to comprehensively response to future climate change, mitigate the adverse impact of future climate change on food production in semi-arid region of Northwest, China.

A New Stonefly Species, Rhopalopsole tricuspis (Leuctridae: Plecoptera), and Three New Records of Stoneflies from the Qinling Mountains of Shaanxi, China

Science.gov (United States)

Qian, Yu-Han; Du, Yu-Zhou

2012-01-01

Plecopteran species (Leuctridae) were collected from the Qinling Mountains in southern Shaanxi Province, China. This mountain range is home to nine species of Leuctridae belonging to two genera, and the species identified in this work include one new species and three new records for the Qinling Mountains, all belonging to the genus Rhopalopsole. The new species is named R. tricuspis Qian and Du, sp. nov. A redescription of R. basinigra Yang and Yang 1995 is supplemented. A key is provided for the adult males of Leuctridae from the Qinling Mountains. PMID:22957649

Sources and characteristics of organochlorine pesticides in the soil and sediment along the Kaidu-Peacock River, Northwest of China

Science.gov (United States)

Chen, Wei; Qi, Shihua; Peng, Fei; Qu, Chengkai; Zhang, Yuan; Xing, Xinli; Zhang, Jiaquan

2016-04-01

Organochlorine pesticides (OCPs) are a sub-group of persistent organic pollutants (POPs), which have raised the concerns from researchers all around the world for several decades. But very little research has been conducted on POPs in the arid zone of Northwest China. More than 100 soil and sediment samples were collected from Kaidu-Peacock River of Xinjiang, Northwest of China, to investigate the organochlorine pesticides (OCPs) in this region analysed by the gas chromatograph equipped with a mass selective detector (GC-MSD). Our pre-study in 2006 (Chen et al. 2011) in the same region, showed that OCPs except o,p'-DDT were detected in sediments from the Peacock River. Similar results were found in the whole river catchment in this investigation. DDTs, HCHs, chlordanes and endosulfans were the dominant OCPs residual in the soil and sediments. This study confirmed that POPs, such as OCPs in this region were contributed to by both local emissions and long-term atmospheric transport and may pose risks to human health and the ecosystem. Chen, W., Jing, M., Bu, J., Ellis Burnet, J., Qi, S., Song, Q., Ke, Y., Miao, J., Liu, M. & Yang, C. (2011) Organochlorine pesticides in the surface water and sediments from the Peacock River Drainage Basin in Xinjiang, China: a study of an arid zone in Central Asia. Environmental Monitoring and Assessment, 177, 1-21.

State-Led Ecotourism Development and Nature Conservation: a Case Study of the Changbai Mountain Biosphere Reserve, China

OpenAIRE

Jianqiong Yuan; Limin Dai; Qingli Wang

2008-01-01

Faced with fiscal constraints and enormous population pressures, 80% of Chinese nature reserves have employed ecotourism as a support and development strategy. Assessing the actual effects of ecotourism at a nature reserve that has a relatively long history of ecotourism development experience may be instructive for other reserves. Therefore, we take Changbai Mountain Biosphere Reserve (CMBR) in northeastern China as a case study, for it is one of the pioneers in embracing ecotourism in China...

Energy investment and trade opportunities emerging in Central Asia, Northwest China

International Nuclear Information System (INIS)

Dorian, J.P.; Abbasovich, T.U.; Tonkopy, M.S.; Jumabekovich, O.A.; Qiu Daxiong

1998-01-01

Cooperation in the business of oil and natural gas among governments of Central Asia and Northwest China could help the countries overcome obstacles to development of their vast petroleum resources. The most important obstacle facing these countries is also the one most widely discussed: limited infrastructure for transporting energy. But there are other problems holding back oil and gas development. They include poor communications infrastructure, unstable government structures, political conflict, payments difficulties, and inadequate energy policies. For countries analyzed in a recent Asian Development Bank (ADB) study of economic cooperation in the region--Uzbekistan, Kazakhstan, the Kyrgyz Republic, and the Xinjiang autonomous region of the People's Republic of China (Xinjiang PRC)--oil and gas are the most abundant and valuable natural resources. While Central Asia is poised to become a major world supplier of energy, especially oil and gas, countries in the region emphasize energy self-sufficiency at the expense of developing new trading linkages. Governments thus tend to ignore the benefits of regional cooperation and remain reluctant to commit to area-wide trade and other forms of cooperation. The paper discusses oil and gas sectors; major energy trends, including restructuring, foreign investment, and energy diversification; opportunities for cooperation; impediments to cooperation; and models of cooperation

Epidermal characters of Tamarix L. (Tamaricaceae from Northwest China and their taxonomic and palaeogeographic implications

Directory of Open Access Journals (Sweden)

Jian-Wei Zhang

2018-04-01

implications of Tamarix in the Late Cenozoic of Northwest China are also discussed. Keywords: Anatomy, Arid region, Epidermis, Ecological adaptation, Phylogenetic evolution, Tamarix, Northwest China

Variations of Ecosystem Service Value in Response to Land-Use Change in the Kashgar Region, Northwest China

OpenAIRE

Aynur Mamat; Ümüt Halik; Aihemaitijiang Rouzi

2018-01-01

Increasing anthropogenic activities have significantly altered ecosystems in arid oasis regions. Estimating the impact on a wide range of ecosystem services is important for decision making and the sustainable development of these regions. This study analyzed time-series Landsat data to determine the influences of oasis land-use changes on the ecosystem services in the Kashgar region in Northwest China. The following results were found. The total value of the ecosystem services in the Kashgar...

Ecosystem Evapotranspiration as a Response to Climate and Vegetation Coverage Changes in Northwest Yunnan, China.

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Hao Yang

Full Text Available Climate and human-driven changes play an important role in regional droughts. Northwest Yunnan Province is a key region for biodiversity conservation in China, and it has experienced severe droughts since the beginning of this century; however, the extent of the contributions from climate and human-driven changes remains unclear. We calculated the ecosystem evapotranspiration (ET and water yield (WY of northwest Yunnan Province, China from 2001 to 2013 using meteorological and remote sensing observation data and a Surface Energy Balance System (SEBS model. Multivariate regression analyses were used to differentiate the contribution of climate and vegetation coverage to ET. The results showed that the annual average vegetation coverage significantly increased over time with a mean of 0.69 in spite of the precipitation fluctuation. Afforestation/reforestation and other management efforts attributed to vegetation coverage increase in NW Yunnan. Both ET and WY considerably fluctuated with the climate factors, which ranged from 623.29 mm to 893.8 mm and -51.88 mm to 384.40 mm over the time period. Spatially, ET in the southeast of NW Yunnan (mainly in Lijiang increased significantly, which was in line with the spatial trend of vegetation coverage. Multivariate linear regression analysis indicated that climatic factors accounted for 85.18% of the ET variation, while vegetation coverage explained 14.82%. On the other hand, precipitation accounted for 67.5% of the WY. We conclude that the continuous droughts in northwest Yunnan were primarily climatically driven; however, man-made land cover and vegetation changes also increased the vulnerability of local populations to drought. Because of the high proportion of the water yield consumed for subsistence and poor infrastructure for water management, local populations have been highly vulnerable to climate drought conditions. We suggest that conservation of native vegetation and development of water

Accumulation, transfer, and potential sources of mercury in the soil-wheat system under field conditions over the Loess Plateau, northwest China

International Nuclear Information System (INIS)

Wang, Shengli; Nan, Zhongren; Prete, Daniel; Ma, Jianmin; Liao, Qin; Zhang, Qian

2016-01-01

There is limited information on accumulation, transfer, and source of mercury in wheats under field conditions over the Loess Plateau, northwest China. The present study collected 26 pairs of topsoil and whole wheat samples (roots, stems, leaves, shells, and grains) from Dongdagou stream watershed and upper Xidagou stream watershed, Baiyin City, northwest China. Hg concentrations from these samples were used to identify their relationships with soil properties, interactions with other metals, localization of Hg in the different wheat tissues, bio-concentration and transfer of Hg, and major sources of Hg in wheat. Results show that Hg levels in 11 out of 26 sampled soils (42.3% of soil samples) exceeded Hg limit of grade II soil environmental quality standards in China (1.0 mg·kg"− "1). Likewise, it was also found that Hg in over 50% of wheat grain samples reached or exceeded the maximum permissible food safety levels (0.02 mg·kg"− "1) according to the General Standard of Contaminants in Food in China (GB 2762-2012). The spatial distribution pattern of Hg in wheats grains was different from that in the sampled soils. Hg concentrations in different wheat tissues were highest in roots, followed by leaves, stalks, shells, and grains, respectively. Bio-concentration factors (BCF) of Hg in almost all grains samples were one or two orders of magnitude lower than that in roots, except for two wheat samples. The translocation factors (TF) of Hg in wheat tissues on average were leaves > stems > shells > grains. The spatial distribution of Hg and its correlation with other heavy metal detected simultaneously in the soil samples suggested that the Hg soil contamination was probably caused by past sewage irrigation practices and atmospheric deposition. Correlation analysis revealed that the principle source of Hg in wheat roots was very likely from Hg contaminated soils. - Highlights: • Hg concentrations in wheats and corresponding soils from loess plateau, northwest

Accumulation, transfer, and potential sources of mercury in the soil-wheat system under field conditions over the Loess Plateau, northwest China

Energy Technology Data Exchange (ETDEWEB)

Wang, Shengli [Key Laboratory for Environmental Pollution Prediction and Control, Gansu Province, College of Earth and Environmental Sciences, Lanzhou University, Lanzhou 730000 (China); Key Laboratory of Western China' s Environmental Systems (Ministry of Education), College of Earth and Environmental Sciences, Lanzhou University, Lanzhou 730000 (China); Nan, Zhongren, E-mail: nanzhongren@lzu.edu.cn [Key Laboratory for Environmental Pollution Prediction and Control, Gansu Province, College of Earth and Environmental Sciences, Lanzhou University, Lanzhou 730000 (China); Key Laboratory of Western China' s Environmental Systems (Ministry of Education), College of Earth and Environmental Sciences, Lanzhou University, Lanzhou 730000 (China); Prete, Daniel [Department of Chemistry and Biology, Ryerson University, Toronto M5B 2K3 (Canada); Ma, Jianmin; Liao, Qin; Zhang, Qian [Key Laboratory for Environmental Pollution Prediction and Control, Gansu Province, College of Earth and Environmental Sciences, Lanzhou University, Lanzhou 730000 (China)

2016-10-15

There is limited information on accumulation, transfer, and source of mercury in wheats under field conditions over the Loess Plateau, northwest China. The present study collected 26 pairs of topsoil and whole wheat samples (roots, stems, leaves, shells, and grains) from Dongdagou stream watershed and upper Xidagou stream watershed, Baiyin City, northwest China. Hg concentrations from these samples were used to identify their relationships with soil properties, interactions with other metals, localization of Hg in the different wheat tissues, bio-concentration and transfer of Hg, and major sources of Hg in wheat. Results show that Hg levels in 11 out of 26 sampled soils (42.3% of soil samples) exceeded Hg limit of grade II soil environmental quality standards in China (1.0 mg·kg{sup −} {sup 1}). Likewise, it was also found that Hg in over 50% of wheat grain samples reached or exceeded the maximum permissible food safety levels (0.02 mg·kg{sup −} {sup 1}) according to the General Standard of Contaminants in Food in China (GB 2762-2012). The spatial distribution pattern of Hg in wheats grains was different from that in the sampled soils. Hg concentrations in different wheat tissues were highest in roots, followed by leaves, stalks, shells, and grains, respectively. Bio-concentration factors (BCF) of Hg in almost all grains samples were one or two orders of magnitude lower than that in roots, except for two wheat samples. The translocation factors (TF) of Hg in wheat tissues on average were leaves > stems > shells > grains. The spatial distribution of Hg and its correlation with other heavy metal detected simultaneously in the soil samples suggested that the Hg soil contamination was probably caused by past sewage irrigation practices and atmospheric deposition. Correlation analysis revealed that the principle source of Hg in wheat roots was very likely from Hg contaminated soils. - Highlights: • Hg concentrations in wheats and corresponding soils from loess

Sichuan Snub-Nosed Monkeys (Rhinopithecus roxellana) Consume Cicadas in the Qinling Mountains, China.

Science.gov (United States)

Yang, Bin; Zhang, Peng; Garber, Paul A; Hedley, Richard; Li, Baoguo

2016-01-01

There is limited information on insectivory in folivorous primates. Here, we report that wild Sichuan snub-nosed monkeys (Rhinopithecus roxellana) consume cicadas (Karenia caelatata) in the Qinling Mountains of China. Our research suggests that snub-nosed monkeys expand their diet and prey on cicadas during summer and early autumn, possibly in response to increased availability of these insects and their relatively high protein and fat content relative to leaves. © 2016 S. Karger AG, Basel.

Characterization, Long-Range Transport and Source Identification of Carbonaceous Aerosols during Spring and Autumn Periods at a High Mountain Site in South China

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Hong-yan Jia

2016-09-01

Full Text Available PM10 (particulate matter samples were collected at Mount Lu, a high elevation mountain site in south China (August and September of 2011; and March, April and May of 2012. Eight carbonaceous fractions of particles were analyzed to characterize the possible carbonaceous emission sources. During the sampling events, daily average concentrations of PM10 at Mount Lu were 97.87 μg/m3 and 73.40 μg/m3 in spring and autumn, respectively. The observed mean organic carbon (OC and element carbon (EC concentrations during spring in PM10 were 10.58 μg/m3 and 2.58 μg/m3, respectively, and those in autumn were 6.89 μg/m3 and 2.40 μg/m3, respectively. Secondary organic carbon concentration was 4.77 μg/m3 and 2.93 μg/m3 on average, accounting for 28.0% and 31.0% of the total OC in spring and autumn, respectively. Relationships between carbonaceous species and results of principal component analysis showed that there were multiple sources contributing to the carbonaceous aerosols at the observation site. Through back trajectory analysis, it was found that air masses in autumn were mainly transported from the south of China, and these have the highest OC but lowest EC concentrations. Air masses in spring transported from northwest China bring 7.77 μg/m3 OC and 2.28 μg/m3 EC to the site, with lower levels coming from other sites. These air mass sources were featured by the effective carbon ratio (ECR.

Sphingomonas qilianensis sp. nov., Isolated from Surface Soil in the Permafrost Region of Qilian Mountains, China.

Science.gov (United States)

Piao, Ai-Lian; Feng, Xiao-Min; Nogi, Yuichi; Han, Lu; Li, Yonghong; Lv, Jie

2016-04-01

A Gram-stain-negative, strictly aerobic, non-motile and rod-shaped bacterial strain, designated X1(T), was isolated from the permafrost region of Qilian Mountains in northwest of China. Phylogenetic analyses of 16S rRNA gene sequence revealed that strain X1(T) was a member of the genus Sphingomonas and shared the highest 16S rRNA gene sequence similarity with Sphingomonas oligophenolica JCM 12082(T) (96.9%), followed by Sphingomonas glacialis CGMCC 1.8957(T) (96.7%) and Sphingomonas alpina DSM 22537(T) (96.4%). Strain X1(T) was able to grow at 15-30 °C, pH 6.0-10.0 and with 0-0.3% NaCl (w/v). The DNA G+C content of the isolate was 64.8 mol%. Strain X1(T)-contained Q-10 as the dominant ubiquinone and C(18:1)ω7c, C(16:1)ω7c, C(16:0) and C(14:0) 2-OH as the dominant fatty acids. The polar lipid profile of strain XI(T)-contained sphingoglycolipid, phosphatidylglycerol, phosphatidylethanolamine, one unidentified glycolipid and two unidentified phospholipid. Due to the phenotypic and genetic distinctiveness and other characteristic studied in this article, we consider X1(T) as a novel species of the genus Sphingomonas and propose to name it Sphingomonas qilianensis sp. nov. The type strain is X1(T) (=CGMCC 1.15349(T) = KCTC 42862(T)).

Stoneflies of the genus Neoperla (Plecoptera, Perlidae from Wuyi Mountain National Nature Reserve, Fujian of China

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Xue-Feng Qin

2013-08-01

Full Text Available The species of the genus Neoperla are reviewed from Wuyi Mountain National Nature Reserve located in the Fujian Province of southeastern China, including the description of a new species, Neoperla brevistyla sp. n. The new species is compared to similar taxa. The first records of five Neoperla species, N. henana Li, Wu & Zhang, 2011, N. similiserecta Wang & Li, 2012, N. qingyuanensis Yang & Yang, 1995, N. xuansongae Li & Li, 2013 and N. tuberculata Wu, 1938 are given for the Wuyi Mountain. A provisional key is provided for facilitating the identification of these species.

Characterizing dust aerosols in the atmospheric boundary layer over the deserts in Northwest China: monitoring network and field observation

Science.gov (United States)

He, Q.; Matimin, A.; Yang, X.

2016-12-01

TheTaklimakan, Gurbantunggut and BadainJaran Deserts with the total area of 43.8×104 km2 in Northwest China are the major dust emission sources in Central Asia. Understanding Central Asian dust emissions and the interaction with the atmospheric boundary layer has an important implication for regional and global climate and environment changes. In order to explore these scientific issues, a monitoring network of 63 sites was established over the vast deserts (Taklimakan Desert, Gurbantunggut Desert and Badain Jaran Desert) in Northwest China for the comprehensive measurements of dust aerosol emission, transport and deposition as well as the atmospheric boundary layer including the meteorological parameters of boundary layer, surface radiation, surface heat fluxes, soil parameters, dust aerosol properties, water vapor profiles, and dust emission. Based on the monitoring network, the field experiments have been conducted to characterize dust aerosols and the atmospheric boundary layer over the deserts. The experiment observation indicated that depth of the convective boundary layer can reach 5000m on summer afternoons. In desert regions, the diurnal mean net radiation was effected significantly by dust weather, and sensible heat was much greater than latent heat accounting about 40-50% in the heat balance of desert. The surface soil and dust size distributions of Northwest China Deserts were obtained through widely collecting samples, results showed that the dominant dust particle size was PM100within 80m height, on average accounting for 60-80% of the samples, with 0.9-2.5% for PM0-2.5, 3.5-7.0% for PM0-10 and 5.0-14.0% for PM0-20. The time dust emission of Taklimakan Desert, Gurbantunggut Desert and Badain Jaran Desert accounted for 0.48%, 7.3%×10-5and 1.9% of the total time within a year, and the threshold friction velocity for dust emission were 0.22-1.06m/s, 0.29-1.5m/s and 0.21-0.59m/s, respectively.

Sweet sorghum performance under irrigated conditions in northwest China : Biomass and its partitioning in inbred and hybrid cultivars at two nitrogen levels

NARCIS (Netherlands)

Fan, F.; Spiertz, J.H.J.; Han, L.P.; Liu, Z.X.; Xie, G.H.

2013-01-01

Effects of cultivar choice and nitrogen supply on biomass yield and dry matter partitioning of sweet sorghum [Sorghum bicolor (L.) Moench] were studied under irrigated conditions in the arid temperate climate of north-west China. Two hybrid cultivars, Zaoshu-1 (ZS 1) and Chuntian-2 (CT 2), and two

Investigating the Impact of Shading Effect on the Characteristics of a Large-Scale Grid-Connected PV Power Plant in Northwest China

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Yunlin Sun

2014-01-01

Full Text Available Northwest China is an ideal region for large-scale grid-connected PV system installation due to its abundant solar radiation and vast areas. For grid-connected PV systems in this region, one of the key issues is how to reduce the shading effect as much as possible to maximize their power generation. In this paper, a shading simulation model for PV modules is established and its reliability is verified under the standard testing condition (STC in laboratory. Based on the investigation result of a 20 MWp grid-connected PV plant in northwest China, the typical shading phenomena are classified and analyzed individually, such as power distribution buildings shading and wire poles shading, plants and birds droppings shading, and front-row PV arrays shading. A series of experiments is also conducted on-site to evaluate and compare the impacts of different typical shading forms. Finally, some feasible solutions are proposed to avoid or reduce the shading effect of PV system during operation in such region.

Analysis of economic burden for patients with cystic echinococcosis in five hospitals in northwest China.

Science.gov (United States)

Wang, Le; Wen, Hao; Feng, Xiaohui; Jiang, Xiaoming; Duan, Xinyu

2012-12-01

The direct and indirect economic burden of human cystic echinococcosis (CE) was investigated in the five specialist hydatid hospitals in Xinjiang, PR China, to provide information for health policy in the future. A total of 2018 CE patients (age range 2-88 years) attending the hospitals were studied between 2004 and 2008. The per-person direct medical cost was US$1493.12 (95% CI 1438.43-1547.80) and the per-person direct non-medical cost was US$19.67. The indirect economic cost was US$1435.96 per person, and the disability-adjusted life-years (DALY) lost was approximately 1.03 DALY/person. This study is the first to combine the human capital method with DALYs to analyse the indirect CE economic burden in northwest China. Factors such as age, occupation and hospital level should be considered when developing polices to reduce the economic burden of CE. Copyright © 2012 Royal Society of Tropical Medicine and Hygiene. Published by Elsevier Ltd. All rights reserved.

Miscellaneous investigations series: Bedrock geologic map of the Lone Mountain pluton area, Esmeralda County, Nevada

International Nuclear Information System (INIS)

Maldonado, F.

1984-01-01

The joint attitudes were measured in the field and plotted on aerial photos at a scale of 1:24,000. The pluton is intensely jointed, primarily as a result of cooling and movement of the magma within a northwest-trending stress field. Foliation, in general, is poorly developed, and quality varies from area to area, but it is best developed close to the contacts with the metasedimentary rocks. A prominent northwest foliation direction was observed that parallels the northwest elongation of the exposed pluton. Faults in the pluton are difficult to identify because of the homogeneity of the rock. Several faults were mapped in the northern part of the area where they have a northeast trend and intersect the northwest-trending lamprophyre dikes with little apparent displacement. A major fault that bounds the northern part of the pluton is downthrown to the north and strikes northeast. This fault offsets the alluvium, the metasedimentary rocks, and the pluton and forms fault scraps as high as 10 m. Aeromagnetic data (US Geological Survey, 1979) suggest the following: (1) the local magnetic highs in the central part of the Lone Mountain pluton are probably related to topographic highs (peaks) where the flight lines are closer to the pluton; (2) a magnetic low in the northeastern part of Lone Mountain coincides with the pluton-country rock contact, which may be very steep; (3) the contours for the southwestern part of the mapped area indicate that the pluton-country rock contact is not as steep as that in the northeastern part and that the pluton probably coalesces at depth with the Weepah pluton, a pluton exposed south of the mapped area; and (4) the contours for the area of the Lone Mountain pluton express a northwest-trending gradient that parallels the northwest elongation of the Lone Mountain pluton and the northwest-trending stress field. 10 refs

Analysis of Precipitation and Drought Data in Hexi Corridor, Northwest China

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Xinyang Yu

2017-05-01

Full Text Available Precipitation data from nine meteorological stations in arid oases of Hexi Corridor, northwest China during 1970–2012 were analyzed to detect trends in precipitation and Standardized Precipitation Index (SPI at multiple time scales using linear regression, Mann–Kendall and Spearman’s Rho tests. The results found that annual precipitation in the observed stations was rare and fell into the arid region category according to the aridity index analysis. The monthly analysis of precipitation found that three stations showed significant increasing trends in different months, while on the annual level, only Yongchang station had a significant increasing trend. The analysis of SPI-12 found three main drought intervals, i.e., 1984–1987, 1991–1992 and 2008–2011, and an extremely dry year among the stations was recorded in 1986; the southeast and middle portions of the study area are expected to have more precipitation and less dry conditions.

Effects of plant phenology and solar radiation on seasonal movement of golden takin in the Qinling Mountains, China

NARCIS (Netherlands)

Zeng, Z.G.; Beck, P.S.A.; Wang, T.; Skidmore, A.K.; Song, Y.L.; Gong, H.S.; Prins, H.H.T.

2010-01-01

The golden takin (Budorcas taxicolor bedfordi) is a large, forest-dwelling ungulate endemic to the Qinling Mountains, China. A recent study showed that golden takin move to different elevations depending on the season, remaining at high elevations in summer, intermediate elevations in winter, and at

Optical properties and source analysis of aerosols over a desert area in Dunhuang, Northwest china

Science.gov (United States)

Ma, Yongjing; Xin, Jinyuan; Ma, Yining; Kong, Lingbin; Zhang, Kequan; Zhang, Wenyu; Wang, Yuesi; Wang, Xiuqin; Zhu, Yongfeng

2017-08-01

Aerosol observational data for 2012 obtained from Dunhuang Station of CARE-China (Campaign on Atmospheric Aerosol Research Network of China) were analyzed to achieve in-depth knowledge of aerosol optical properties over Dunhuang region. The results showed that the annual average aerosol optical depth (AOD) at 500 nm was 0.32±0.06, and the Ångström exponent ( α) was 0.73 ± 0.27. Aerosol optical properties revealed significant seasonal characteristics. Frequent sandstorms in MAM (March-April-May) resulted in the seasonal maximum AOD, 0.41 ± 0.04, and a relatively smaller α value, 0.44±0.04. The tourism seasons, JJA (June-July-August) and SON (September-October-November) coincide with serious emissions of small anthropogenic aerosols. While in DJF (December-January-February), the composition of the atmosphere was a mixture of dust particles and polluted aerosols released by domestic heating; the average AOD and α were 0.29 ± 0.02 and 0.66 ± 0.17, respectively. Different air masses exhibited different degrees of influence on the aerosol concentration over Dunhuang in different seasons. During MAM, ranges of AOD (0.11-1.18) and α (0.06-0.82) were the largest under the dust influence of northwest-short-distance air mass in the four trajectories. Urban aerosols transported by northwest-short-distance air mass accounted for a very large proportion in JJA and the mixed aerosols observed in SON were mainly conveyed by air masses from the west. In DJF, the similar ranges of AOD and α under the three air mass demonstrated the analogous diffusion effects on regional pollutants over Dunhuang.

Atmospheric PAHs, NPAHs, and OPAHs at an urban, mountainous, and marine sites in Northern China: Molecular composition, sources, and ageing

Science.gov (United States)

Zhang, Junmei; Yang, Lingxiao; Mellouki, Abdelwahid; Chen, Jianmin; Chen, Xiangfeng; Gao, Ying; Jiang, Pan; Li, Yanyan; Yu, Hao; Wang, Wenxing

2018-01-01

18 gaseous and particulate polycyclic aromatic hydrocarbons (PAHs), 16 nitro-derivative (NPAHs), and 7 oxy-derivative (OPAHs) were analyzed by Gas Chromatography-Mass Spectrometry (GC-MS) at three locations in Northern China, an urban site (Jinan), a marine site (Tuoji island), and a mountain site (Mt. Tai). The combined gas and particulate concentrations of 18 PAHs, 16 NPAHs, and 7 OPAHs were highest at the urban site (305.91, 2.80, and 9.05 ng/m3, respectively) and lowest at the mountain location (37.83, 0.27, and 1.59 ng/m3, respectively). A noticeable increase in the high molecular weight PAHs was observed during polluted conditions compared to clean conditions. Diagnostic ratios clearly demonstrated that coal/biomass combustion was the major PAH source in Northern China. The particulate PAHs were the most aged at the mountain site due to long-distance atmospheric transport. The formation rate of NPAHs was most efficient at the mountain location and during heavily polluted days at the urban and marine sites. In addition, the main formation pathway for NPAHs was through the OH initiated secondary reaction. NO3 radicals most significantly contributed to the NPAHs formation at night, during clear weather, and at the mountain site. The logKp value was lowest at the urban site for most individual compounds and highest at the mountain site. Higher logKp was found for NPAHs and OPAHs compared with their corresponding parent PAHs. The linear regression of logKp vs logPL0 at the three sites suggested that the gas-particle partitioning of PAHs might be in non-equilibrium.

Land Use Changes of an Aeolian-Loessial Soil Area in Northwest China: Implications for Ecological Restoration

Institute of Scientific and Technical Information of China (English)

CHEN Yu-Fu; LIU Yan-Sui; WANG Jing; YAN Jian-Ping; GUO Xu-Dong

2009-01-01

China has experienced dramatic land use changes over recent decades,with marked environmental and socio-economic consequences.Hcngshan County,located in the aeolian-loessial area of Northwest China,was investigated to illustrate land use changes and their implications for environmental and long-term rural economic development.The farmland in Hengshan County significantly decreased during 1990-2003,whereas forest land and grassland increased.The conversion rates of farmland,orchard land,forest land and construction land varied markedly among different periods:1990-1995,1995-2000 and 2000-2003.Conversion of orchard land,grassland and construction land was dominant in 1990-1995,whereas the conversion of farmland to forest land mainly occurred in 2000-2003.The results suggested a profound transition in institutional policy and political economy of land management,including implementation of integrated soil erosion control projects,adoption of a market-oriented economy and the 'Grain-for-Green' policy,during this period in China.To achieve long-term sustainable land use in Hengshan County,efforts should aim at increasing off-farm income of rural families as well as establishing land-economizing mechanisms to promote land productivity,in addition to conservation measures.

Variations of Ecosystem Service Value in Response to Land-Use Change in the Kashgar Region, Northwest China

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Aynur Mamat

2018-01-01

Full Text Available Increasing anthropogenic activities have significantly altered ecosystems in arid oasis regions. Estimating the impact on a wide range of ecosystem services is important for decision making and the sustainable development of these regions. This study analyzed time-series Landsat data to determine the influences of oasis land-use changes on the ecosystem services in the Kashgar region in Northwest China. The following results were found. The total value of the ecosystem services in the Kashgar region were approximately $10,845.3, $11,218.6, $10,291.7, and $10,127.3 million in 1986, 1996, 2005, and 2015, respectively. The water supply, waste treatment, biodiversity protection, and recreation and cultural services were the four ecosystem services with the highest service value, contributing 77.05% of the total ecosystem services. The combined contribution rate of food production and raw material value was only about 4.02%, relatively small. The sensitivity analysis indicated that the estimated total ecosystem service value (ESV for this study area was relatively inelastic with respect to the value coefficients. The findings of this study will be crucial for maintaining the stability and sustainable development of the oasis region, where socio-economic development and the integrity of the natural ecosystem complement each other. Furthermore, the results provide a scientific basis for decision makers in land use management, and provide a reference for researchers in the Northwest China.

Bacterioplankton community composition along a salinity gradient of sixteen high-mountain lakes located on the Tibetan Plateau, China

NARCIS (Netherlands)

Wu, Q.L.; Zwart, G.; Schauer, M.; Kamst-van Agterveld, M.P.; Hahn, M.W.

2006-01-01

The influence of altitude and salinity on bacterioplankton community composition (BCC) in 16 high-mountain lakes located at altitudes of 2,817 to 5,134 m on the Eastern Qinghai-Xizang (Tibetan) Plateau, China, spanning a salinity gradient from 0.02% (freshwater) to 22.3% (hypersaline), was

Potential transport pathways of dust emanating from the playa of Ebinur Lake, Xinjiang, in arid northwest China

Science.gov (United States)

Ge, Yongxiao; Abuduwaili, Jilili; Ma, Long; Wu, Na; Liu, Dongwei

2016-09-01

In this paper, the HYSPLIT model, driven with reanalysis meteorological data from 1978 to 2013, was used to understand the potential transport characteristics of dust and salt dust emanating from the playa of Ebinur Lake in arid northwest China. Daily air parcel trajectories were computed forward for 8 days from an origin centered over Ebinur Lake at 100 m above ground level. Air parcel trajectory density plots were mapped for seven levels: 0-100 m agl., 100-500 m agl., 500-1000 m agl., 1000-1500 m agl., 1500-2000 m agl., 2000-3000 m agl., and 3000-5000 m agl. These show that potential dust transport pathways have clear seasonal differentiation. The potential transport distance of dust and salt dust is greatest in spring and summer. In autumn and winter, the potential transport of the high-density air trajectory is below 1000 m traveling a shorter distance. Potential dust transport pathways showed notifying directivity in different seasons and heights. Southeast in spring and summer, and north to northeast in autumn and winter are the two main potential transport channels of dust and salt dust. Accordingly, dust and salt dust from the playa of Ebinur Lake may influence the atmospheric processes and biogeochemical cycles of a vast region. The main area of influence of dust and salt dust is close to the source area, and will significantly accelerate the melting of snow and ice in the Tianshan Mountains. This highlights the urgent need to combine remote sensing, isotope and other methods to further research the transport characteristics of dust and salt dust from the playa of the Ebinur Lake.

Big mountains but small barriers: population genetic structure of the Chinese wood frog (Rana chensinensis) in the Tsinling and Daba Mountain region of northern China.

Science.gov (United States)

Zhan, Aibin; Li, Cheng; Fu, Jinzhong

2009-04-09

Amphibians in general are poor dispersers and highly philopatric, and landscape features often have important impacts on their population genetic structure and dispersal patterns. Numerous studies have suggested that genetic differentiation among amphibian populations are particularly pronounced for populations separated by mountain ridges. The Tsinling Mountain range of northern China is a major mountain chain that forms the boundary between the Oriental and Palearctic zoogeographic realms. We studied the population structure of the Chinese wood frog (Rana chensinensis) to test whether the Tsinling Mountains and the nearby Daba Mountains impose major barriers to gene flow. Using 13 polymorphic microsatellite DNA loci, 523 individuals from 12 breeding sites with geographical distances ranging from 2.6 to 422.8 kilometers were examined. Substantial genetic diversity was detected at all sites with an average of 25.5 alleles per locus and an expected heterozygosity ranging from 0.504 to 0.855, and two peripheral populations revealed significantly lower genetic diversity than the central populations. In addition, the genetic differentiation among the central populations was statistically significant, with pairwise FST values ranging from 0.0175 to 0.1625 with an average of 0.0878. Furthermore, hierarchical AMOVA analysis attributed most genetic variation to the within-population component, and the between-population variation can largely be explained by isolation-by-distance. None of the putative barriers detected from genetic data coincided with the location of the Tsinling Mountains. The Tsinling and Daba Mountains revealed no significant impact on the population genetic structure of R. chensinensis. High population connectivity and extensive juvenile dispersal may account for the significant, but moderate differentiation between populations. Chinese wood frogs are able to use streams as breeding sites at high elevations, which may significantly contribute to the

Establishment and assessment of cataract surgery in Day-care Unit at northwest of China

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Xiu-Li Zhang

2018-04-01

Full Text Available AIM: To describe the protocol and economic cost of the Day-care Unit cataract surgery procedure in northwest of China.METHODS: Patients who received phacoemulcification and intraocular lens implantation in both Day-care Unit and regular Unit were recruited from January 2016 to December 2016. The baseline data and average cost were recorded and analyzed. Furthermore, satisfaction questionnaire of patients were collected.RESULTS: Patients with Day-care Unit showed shorter registration duration, less cost including housing and nursing charge as well as higher rate of patient satisfaction. Meanwhile, Day-care Unit shorten the time the doctors and nurses spending on filling the medical charts.CONCLUSION:Day-care Unit cataract surgery procedure could benefit both patients and medical staffs and is worthy to generalize.

Geology of Gable Mountain-Gable Butte Area

International Nuclear Information System (INIS)

Fecht, K.R.

1978-09-01

Gable Mountain and Gable Butte are two ridges which form the only extensive outcrops of the Columbia River Basalt Group in the central portion of the Pasco Basin. The Saddle Mountains Basalt and two interbedded sedimentary units of the Ellensburg Formation crop out on the ridges. These include, from oldest to youngest, the Asotin Member (oldest), Esquatzel Member, Selah Interbed, Pomona Member, Rattlesnake Ridge Interbed, and Elephant Mountain Member (youngest). A fluvial plain composed of sediments from the Ringold and Hanford (informal) formations surrounds these ridges. The structure of Gable Mountain and Gable Butte is dominated by an east-west-trending major fold and northwest-southeast-trending parasitic folds. Two faults associated with the uplift of these structures were mapped on Gable Mountain. The geomorphic expression of the Gable Mountain-Gable Butte area resulted from the comlex folding and subsequent scouring by post-basalt fluvial systems

Toxoplasma gondii, Dirofilaria immitis, feline immunodeficiency virus (FIV), and feline leukemia virus (FeLV) infections in stray and pet cats (Felis catus) in northwest China: co-infections and risk factors.

Science.gov (United States)

Cong, Wei; Meng, Qing-Feng; Blaga, Radu; Villena, Isabelle; Zhu, Xing-Quan; Qian, Ai-Dong

2016-01-01

This study was conducted to estimate the prevalence of Toxoplasma gondii, Dirofilaria immitis, feline immunodeficiency virus (FIV), and feline leukemia virus (FeLV) infections among stray and pet cats in Lanzhou, northwest China, and to identify the influence of age, gender, and regions on seropositivity. T. gondii antibodies were examined in cat sera by the modified agglutination test (MAT). The circulating antigens of D. immitis and FeLV and specific antibodies to FIV were examined using kits commercially available. The overall prevalence of T. gondii, FIV, FeLV, and D. immitis was 19.34, 9.12, 11.33, and 3.04 %, respectively. For the genetic characterization of T. gondii genotypes in cats, genomic DNA was extracted from the seropositive cats and the T. gondii B1 gene was amplified using a semi-nested PCR. DNA samples giving positive B1 amplification were then genotyped using multilocus PCR-RFLP. Two T. gondii genotypes (ToxoDB#9 and ToxoDB#1) were identified. Results of the multivariate logistic regression analysis showed that older cats are more likely to be seropositive than juveniles for T. gondii, FIV, FeLV, and D. immitis. This is the first report of T. gondii genotypes in cats in northwest China. Moreover, the present study is the first study of retrovirus and D. immitis seroprevalence in cats in China. The results revealed that T. gondii, FIV, and FeLV infections are common in stray and pet cats in northwest China.

Heavy metal pollution assessment, source identification, and health risk evaluation in Aibi Lake of northwest China.

Science.gov (United States)

Zhaoyong, Zhang; Xiaodong, Yang; Shengtian, Yang

2018-01-08

This study sought to analyze heavy metal (Pb, Zn, Cu, Ni, Mn, and Fe) pollution status in the waters of Aibi Lake in northwest China through the use of an applied comprehensive pollution index, health risk model, and multivariate statistical analyses in combination with the lake's land use types. Results showed that (1) the maximum (average) values of the heavy metals Pb, Zn, Cu, Ni, Mn, and Fe were 0.0644 (0.0123), 0.0006 (0.0002), 0.0009 (0.0032), 0.1235 (0.0242), 0.0061 (0.0025), and 0.0222 (0.0080) μg/L, respectively. Among these, in all the samples, Pb and Ni exceeded the standard and acceptable values put forth by the World Health Organization by 21.13 and 25.67%, respectively. Ni also exceeded (30.16%) the third grade of the Environmental Quality Standards for Surface Water of China. The levels of the six heavy metals were all within the fishery and irrigation water quality standard ranges in China. (2) The average values for single pollution index of heavy metals Pb, Zn, Cu, Ni, Mn, and Fe were 1.000, 0.0006, 0.0009, 3.000, 0.060, and 0.070, respectively, among which Ni levels indicated moderate to significant pollution, while others indicated healthy levels. (3) Health risk evaluation showed that the R n values for Pb, Zn, Cu, Mn, and Fe were 1.8 × 10 -4 , 5.33 × 10 -9 , 4.80 × 10 -7 , 1.08 × 10 -6 , and 2.51 × 10 -7  a -1 , respectively, of which, in all samples, Pb and Ni contents all exceeded the maximum acceptable risk levels according to the International Commission on Radiological Protection (ICRP) as well as the U.S. Environment Protection Agency. (4) Combining with multivariate statistical analyses along with the land use distribution within the lake basin, Pb, Zn, Cu, Ni, and Mn were mainly influenced by the agriculture production and emission from urban lives and traffics, and Fe mainly originated from the natural environment. The results of this research can provide reference values for heavy metal pollution

Stratigraphic and structural framework of Yucca Mountain, Nevada

International Nuclear Information System (INIS)

Spengler, R.W.; Fox, K.F. Jr.

1988-01-01

Yucca Mountain is located within the southwestern Nevada volcanic field, ∼140 km northwest of Las Vegas, Nevada, and 50 km northeast of Death Valley, California. The mountain consist of a series of long, linear, north-trending volcanic ridges that approach an 1800-m maximum elevation near The Prow. The broad intermontane alluviated valleys of Crater Flat, the Amargosa Desert, and Jackass Flats, averaging 800 to 1100 m in elevation, form the western, southern, and eastern margins of Yucca Mountain, respectively. North of The Prow, Yucca Mountain merges with other volcanic highlands that flank the southern rim of the Timber Mountain-Oasis Valley caldera complex. The stratigraphy and structure of the area are discussed. Future geologic studies will attempt to determine if faults extend beneath Yucca Mountain, and, if present, their potential effects on the hydrologic and tectonic regimes

Chemical, Mechanical, and Durability Properties of Concrete with Local Mineral Admixtures under Sulfate Environment in Northwest China.

Science.gov (United States)

Nie, Qingke; Zhou, Changjun; Shu, Xiang; He, Qiang; Huang, Baoshan

2014-05-13

Over the vast Northwest China, arid desert contains high concentrations of sulfate, chloride, and other chemicals in the ground water, which poses serious challenges to infrastructure construction that routinely utilizes portland cement concrete. Rapid industrialization in the region has been generating huge amounts of mineral admixtures, such as fly ash and slags from energy and metallurgical industries. These industrial by-products would turn into waste materials if not utilized in time. The present study evaluated the suitability of utilizing local mineral admixtures in significant quantities for producing quality concrete mixtures that can withstand the harsh chemical environment without compromising the essential mechanical properties. Comprehensive chemical, mechanical, and durability tests were conducted in the laboratory to characterize the properties of the local cementitious mineral admixtures, cement mortar and portland cement concrete mixtures containing these admixtures. The results from this study indicated that the sulfate resistance of concrete was effectively improved by adding local class F fly ash and slag, or by applying sulfate resistance cement to the mixtures. It is noteworthy that concrete containing local mineral admixtures exhibited much lower permeability (in terms of chloride ion penetration) than ordinary portland cement concrete while retaining the same mechanical properties; whereas concrete mixtures made with sulfate resistance cement had significantly reduced strength and much increased chloride penetration comparing to the other mixtures. Hence, the use of local mineral admixtures in Northwest China in concrete mixtures would be beneficial to the performance of concrete, as well as to the protection of environment.

Quantitative Analysis and Comparison of BMI among Han, Tibetan, and Uygur University Students in Northwest China

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Bai Jingya

2013-01-01

Full Text Available Objectives. To fully analyze and compare BMI among Han, Tibetan, and Uygur university students, to discuss the differences in their physical properties and physical health, and thus to provide some theoretical suggestions for the improvement of students’ physical health. Methods. The cross-sectional random cluster sampling was used to investigate 10103 Han, Tibetan, and Uygur university students, aged 20–24 in Northwest China, and their height and weight were measured to calculate BMI. The BMI classification criteria for Chinese established by Work Group on Obesity in China (WGOC were used for screening. Results. Han, Tibetan, and Uygur university students show low obesity rates but high overweight rates. Han, Tibetan, and Uygur university students present a high rate of underweight, normal weight, and overweight, respectively. Female Han students show higher underweight and normal weight rates, but lower overweight and obesity rates, than male Han students. Female Tibetan students show higher normal weight rate, but lower overweight and obesity rates, than male Tibetan students. BMI increases with age for male students but decreases with age for female students. Male Uygur students show higher obesity rate than female Uygur students. Tibetan and Uygur university students have higher BMI than other minorities in South China.

Quantitative Analysis and Comparison of BMI among Han, Tibetan, and Uygur University Students in Northwest China

Science.gov (United States)

Jingya, Bai; Ye, He; Jing, Wang; Xi, Huanjiu; Tao, Hai

2013-01-01

Objectives. To fully analyze and compare BMI among Han, Tibetan, and Uygur university students, to discuss the differences in their physical properties and physical health, and thus to provide some theoretical suggestions for the improvement of students' physical health. Methods. The cross-sectional random cluster sampling was used to investigate 10103 Han, Tibetan, and Uygur university students, aged 20–24 in Northwest China, and their height and weight were measured to calculate BMI. The BMI classification criteria for Chinese established by Work Group on Obesity in China (WGOC) were used for screening. Results. Han, Tibetan, and Uygur university students show low obesity rates but high overweight rates. Han, Tibetan, and Uygur university students present a high rate of underweight, normal weight, and overweight, respectively. Female Han students show higher underweight and normal weight rates, but lower overweight and obesity rates, than male Han students. Female Tibetan students show higher normal weight rate, but lower overweight and obesity rates, than male Tibetan students. BMI increases with age for male students but decreases with age for female students. Male Uygur students show higher obesity rate than female Uygur students. Tibetan and Uygur university students have higher BMI than other minorities in South China. PMID:24453807

Assessing Dryland Ecosystem Services in Xinjiang, Northwest China

Science.gov (United States)

Siew, T. F.; Brauman, K. A.; Zuo, L.; Doll, P. M.

2014-12-01

Dryland ecosystems, including grassland, forest, and irrigated cropland, cover about 41% of earth's land area and are inhabited by over two billion people. In drylands, particularly arid and semiarid areas, the production of ecosystem services is primarily constrained by freshwater availability. Often, water allocated to production by one ecosystem or of one ecosystem service negatively impacts other ecosystems or ecosystem services (ESS). The challenge is to determine how much water should be allocated to which ecosystems (natural and manmade) such that multiple ESS are maximized, thus improving overall well-being. This strategic management decision must be supported by knowledge about spatial and temporal availability of water and its relationship to production (location and scale) of ESS that people receive. We assess the spatial and temporal relationships between water availability and ESS production in Xinjiang, Northwest China. We address four questions: (1) What services are produced by which ecosystems with water available? (2) Where are these services produced? (3) Who uses the services produced? (4) How the production of services changes with variability of water available? Using existing global, national, and regional spatial and statistical data, we assess food, fiber, livestock, and wood production as well as unique forest landscapes (as a proxy for aesthetic appreciation and habitats for unique animals and plants) and protection from dust storms. Irrigation is necessary for crop production in Xinjiang. The production of about 4.2 million tons of wheat and 500,000 tons of cotton requires more than 2 km3 of water each year. This is an important source of food and income for local residents, but the diverted water has negative and potentially costly impacts on downstream forests that potentially provide aesthetic services and protection from dust. Our analyses also show that cropland had increased by about 1.6 million ha from 1987 to 2010, while

Slope Controls Grain Yield and Climatic Yield in Mountainous Yunnan province, China

Science.gov (United States)

Duan, X.; Rong, L.; Gu, Z.; Feng, D.

2017-12-01

Mountainous regions are increasingly vulnerable to food insecurity because of limited arable land, growing population pressure, and climate change. Development of sustainable mountain agriculture will require an increased understanding of the effects of environmental factors on grain and climatic yields. The objective of this study was to explore the relationships between actual grain yield, climatic yield, and environmental factors in a mountainous region in China. We collected data on the average grain yield per unit area in 119 counties in Yunnan province from 1985 to 2012, and chose 17 environmental factors for the same period. Our results showed that actual grain yield ranged from 1.43 to 6.92 t·ha-1, and the climatic yield ranged from -0.15 to -0.01 t·ha-1. Lower climatic yield but higher grain yield was generally found in central areas and at lower slopes and elevations in the western and southwestern counties of Yunnan province. Higher climatic yield but lower grain yield were found in northwestern parts of Yunnan province on steep slopes. Annual precipation and temperature had a weak influence on the climatic yield. Slope explained 44.62 and 26.29% of the variation in grain yield and climatic yield. The effects of topography on grain and climatic yields were greater than climatic factors. Slope was the most important environmental variable for the variability in climatic and grain yields in the mountainous Yunnan province due to the highly heterogeneous topographic conditions. Conversion of slopes to terraces in areas with higher climatic yields is an effective way to maintain grain production in response to climate variability. Additionally, soil amendments and soil and water conservation measures should be considered to maintain soil fertility and aid in sustainable development in central areas, and in counties at lower slopes and elevations in western and southwestern Yunnan province.

Big mountains but small barriers: Population genetic structure of the Chinese wood frog (Rana chensinensis in the Tsinling and Daba Mountain region of northern China

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Li Cheng

2009-04-01

Full Text Available Abstract Background Amphibians in general are poor dispersers and highly philopatric, and landscape features often have important impacts on their population genetic structure and dispersal patterns. Numerous studies have suggested that genetic differentiation among amphibian populations are particularly pronounced for populations separated by mountain ridges. The Tsinling Mountain range of northern China is a major mountain chain that forms the boundary between the Oriental and Palearctic zoogeographic realms. We studied the population structure of the Chinese wood frog (Rana chensinensis to test whether the Tsinling Mountains and the nearby Daba Mountains impose major barriers to gene flow. Results Using 13 polymorphic microsatellite DNA loci, 523 individuals from 12 breeding sites with geographical distances ranging from 2.6 to 422.8 kilometers were examined. Substantial genetic diversity was detected at all sites with an average of 25.5 alleles per locus and an expected heterozygosity ranging from 0.504 to 0.855, and two peripheral populations revealed significantly lower genetic diversity than the central populations. In addition, the genetic differentiation among the central populations was statistically significant, with pairwise FST values ranging from 0.0175 to 0.1625 with an average of 0.0878. Furthermore, hierarchical AMOVA analysis attributed most genetic variation to the within-population component, and the between-population variation can largely be explained by isolation-by-distance. None of the putative barriers detected from genetic data coincided with the location of the Tsinling Mountains. Conclusion The Tsinling and Daba Mountains revealed no significant impact on the population genetic structure of R. chensinensis. High population connectivity and extensive juvenile dispersal may account for the significant, but moderate differentiation between populations. Chinese wood frogs are able to use streams as breeding sites at high

Changes in precipitating snow chemistry with seasonality in the remote Laohugou glacier basin, western Qilian Mountains.

Science.gov (United States)

Dong, Zhiwen; Qin, Dahe; Qin, Xiang; Cui, Jianyong; Kang, Shichang

2017-04-01

Trace elements in the atmosphere could provide information about regional atmospheric pollution. This study presented a whole year of precipitation observation data regarding the concentrations of trace metals (e.g., Cr, Ni, Cu, Mn, Cd, Mo, Pb, Sb, Ti, and Zn), and a TEM-EDX (transmission electron microscope-energy dispersive X-ray spectrometer) analysis from June 2014 to September 2015 at a remote alpine glacier basin in Northwest China, the Laohugou (LHG) basin (4200 m a.s.l.), to determine the regional scale of atmospheric conditions and chemical processing in the free troposphere in the region. The results of the concentrations of trace metals showed that, although the concentrations generally were lower compared with that of surrounding rural areas (and cities), they showed an obviously higher concentration and higher EFs in winter (DJF) and a relatively lower concentration and lower EFs in summer (JJA) and autumn (SON), implying clearly enhanced winter pollution of the regional atmosphere in Northwest China. The TEM observed residue in precipitation that was mainly composed of types of dust, salt-dust, BC-fly ash-soot, and organic particles in precipitation, which also showed remarked seasonal change, showing an especially high ratio of BC-soot-fly ash particles in winter precipitation compared with that of other seasons (while organic particles were higher in the summer), indicating significant increased anthropogenic particles in the winter atmosphere. The source of increased winter anthropogenic pollutants mainly originated from emissions from coal combustion, e.g., the regional winter heating supply for residents and cement factories in urban and rural regions of Northwest China. Moderate Resolution Imaging Spectroradiometer (MODIS) atmospheric optical depth (AOD) also showed a significant influence of regional atmospheric pollutant emissions over the region in winter. In total, this work indicated that the atmospheric environment in western Qilian

How to help woody plants to overcome drought stress?-a control study of four tree species in Northwest China.

Science.gov (United States)

Liu, Xiaozhen; Zhang, Shuoxin

2010-05-01

Water is essential for plants and involves most physical and chemical processes within their lifecycles. Drought stress is a crucial limiting factor for plant growth and production. 48% of the land in China is arid and semi-arid, and non-irrigated land occupies approximately 51.9% of the total cultivated areas. Therefore, studies on plant drought resistant mechanisms have great significance for improving water use efficiency and thus increasing productivity of economical plants. Prior research has shown that the application of nitrogenous fertilizer affects the drought-resistant characteristics of plants. This study aimed to reveal the effect of nitrogenous fertilizer on physiological aspects and its impact on the drought resistance of four tree species (Robinia pseudoacacia L., Ligustrum lucidum Ait., Acer truncatum Bge. and Ulmus pumila L. ) in northwest China. Three levels of nitrogen fertilization (46% N based of urea adjusted to: 5g/15g soil, 15g/15g soil and 25g/15g soil) and an additional control study were applied to 2-year-old well-grown seedlings under drought conditions (30% field moisture capacity). Stomatal conductance, transpiration rate and net photosynthetic rate were measured by a LI-6400 photosynthesis system, while water use efficiency was calculated from net photosynthesis rate and transpiration rate. The results revealed that as the amount of urea applied was raised, stomatal conductance, transpiration rate and net photosynthetic rate decreased significantly, and thus water use efficiency significantly increased. It is therefore concluded that the application of nitrogenous fertilizer regulated physiological parameters by reducing stomata conductance to improve water use efficiency. In addition, among the four tree species, U. pumila had the maximum value of water use efficiency under the same drought condition. The outcome of this study provides a guided option for forest management in arid and semi-arid areas of northwest China.

Relationship between tourism development and vegetated landscapes in Luya Mountain Nature Reserve, Shanxi, China.

Science.gov (United States)

Cheng, Zhan-Hong; Zhang, Jin-Tun

2005-09-01

The relationship between tourism development and vegetated landscapes is analyzed for the Luya Mountain Nature Reserve (LMNR), Shanxi, China, in this study. Indices such as Sensitive Level (SL), Landscape Importance Value (LIV), information index of biodiversity (H'), Shade-tolerant Species Proportion (SSP), and Tourism Influencing Index (TII) are used to characterize vegetated landscapes, the impact of tourism, and their relationship. Their relationship is studied by Two-Way Indicator Species Analysis (TWINSPAN) and Detrended Correspondence Analysis (DCA). TWINSPAN gives correct and rapid partition to the classification, and DCA ordination shows the changing tendency of all vegetation types based on tourism development. These results reflect the ecological relationship between tourism development and vegetated landscapes. In Luya Mountain Nature Reserve, most plant communities are in good or medium condition, which shows that these vegetated landscapes can support more tourism. However, the occurrence of the bad condition shows that there is a severe contradiction between tourism development and vegetated landscapes.

Biomass and carbon dynamics of a tropical mountain rain forest in China.

Science.gov (United States)

Chen, DeXiang; Li, YiDe; Liu, HePing; Xu, Han; Xiao, WenFa; Luo, TuShou; Zhou, Zhang; Lin, MingXian

2010-07-01

Biometric inventories for 25 years, from 1983 to 2005, indicated that the Jianfengling tropical mountain rain forest in Hainan, China, was either a source or a modest sink of carbon. Overall, this forest was a small carbon sink with an accumulation rate of (0.56+/-0.22) Mg C ha(-1)yr(-1), integrated from the long-term measurement data of two plots (P9201 and P8302). These findings were similar to those for African and American rain forests ((0.62+/-0.23) Mg C ha(-1)yr(-1)). The carbon density varied between (201.43+/-29.38) Mg C ha(-1) and (229.16+/-39.2) Mg C ha(-1), and averaged (214.17+/-32.42) Mg C ha(-1) for plot P9201. Plot P8302, however, varied between (223.95+/-45.92) Mg C ha(-1) and (254.85+/-48.86) Mg C ha(-1), and averaged (243.35+/-47.64) Mg C ha(-1). Quadratic relationships were found between the strength of carbon sequestration and heavy rainstorms and dry months. Precipitation and evapotranspiration are two major factors controlling carbon sequestration in the tropical mountain rain forest.

Linear and nonlinear characteristics of the runoff response to regional climate factors in the Qira River basin, Xinjiang, Northwest China.

Science.gov (United States)

Xue, Jie; Gui, Dongwei

2015-01-01

The inland river watersheds of arid Northwest China represent an example of how, in recent times, climatic warming has increased the complexity of Earth's hydrological processes. In the present study, the linear and nonlinear characteristics of the runoff response to temperature and precipitation were investigated in the Qira River basin, located on the northern slope of the Kunlun Mountains. The results showed that average temperature on annual and seasonal scales has displayed a significantly increasing trend, but this has not been reflected in accumulated precipitation and runoff. Using path analysis, a positive link between precipitation and runoff was found both annually and in the summer season. Conversely, it was found that the impact of temperature on runoff has been negative since the 1960s, attributable to higher evaporation and infiltration in the Qira River basin. Over the past 50 years, abrupt changes in annual temperature, precipitation and runoff occurred in 1997, 1987 and 1995, respectively. Combined with analysis using the correlation dimension method, it was found that the temperature, precipitation and runoff, both annually and seasonally, possessed chaotic dynamic characteristics, implying that complex hydro-climatic processes must be introduced into other variables within models to describe the dynamics. In addition, as determined via rescaled range analysis, a consistent annual and seasonal decreasing trend in runoff under increasing temperature and precipitation conditions in the future should be taken into account. This work may provide a theoretical perspective that can be applied to the proper use and management of oasis water resources in the lower reaches of river basins like that of the Qira River.

Paleogene Sediment Character of Mountain Front Central Sumatra Basin

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P. A. Suandhi

2014-07-01

Full Text Available DOI: 10.17014/ijog.v8i3.164The SE-NW trending Mountain Front of Central Sumatra Basin is located in the southern part of the basin. The Mountain Front is elongated parallel to the Bukit Barisan Mountain, extending from the Regencies of North Padang Lawas (Gunung Tua in the northwest, Rokan Hulu, Kampar, Kuantan Singingi, and Inderagiri Hulu Regency in the southeast. The Palaeogene sediments also represent potential exploration objectives in Central Sumatra Basin, especially in the mountain front area. Limited detailed Palaeogene sedimentology information cause difficulties in hydrocarbon exploration in this area. Latest age information and attractive sediment characters based on recent geological fieldwork (by chaining method infer Palaeogene sediment potential of the area. The Palaeogene sedimentary rock of the mountain front is elongated from northwest to southeast. Thickness of the sedimentary unit varies between 240 - 900 m. Palynology samples collected recently indicate that the oldest sedimentary unit is Middle Eocene and the youngest one is Late Oligocene. This latest age information will certainly cause significant changes to the existing surface geological map of the mountain front area. Generally, the Palaeogene sediments of the mountain front area are syn-rift sediments. The lower part of the Palaeogene deposit consists of fluvial facies of alluvial fan and braided river facies sediments. The middle part consists of fluvial meandering facies, lacustrine delta facies, and turbidity lacustrine facies sediments. The upper part consists of fluvial braided facies and transitional marine facies sediments. Volcanism in the area is detected from the occurrence of volcanic material as lithic material and spotted bentonite layers in the middle part of the mountain front area. Late rifting phase is indicated by the presence of transitional marine facies in the upper part of the Palaeogene sediments.

Description of two new Capnia species (Plecoptera: Capniidae) from the Hengduan Mountains of southwestern China.

Science.gov (United States)

Chen, Zhi-Teng; DU, Yu-Zhou

2017-06-07

Two new species of the genus Capnia from the Hengduan Mountains of southwestern China, C. oblata sp. nov. and C. xiei sp. nov. are described and illustrated as new members of the C. cordata Kimmins species group. Capnia oblata sp. nov. is characterized by posteromedial process of tergum 9 connecting antecosta with the medial sclerite bar. Capnia xiei sp. nov. is characterized by main epiproct sclerite bifurcate apically and basally with a bilamellar structure. The new species are compared with similar taxa.

Effects of smoking and alcohol consumption on lipid profile in male adults in northwest rural China.

Science.gov (United States)

Li, X X; Zhao, Y; Huang, L X; Xu, H X; Liu, X Y; Yang, J J; Zhang, P J; Zhang, Y H

2018-04-01

To determine the individual and combined influences of smoking and alcohol consumption on lipid profile in male adults in northwest rural China. Cross-sectional study. In total, 4614 subjects were enrolled in the cross-sectional study, performed between 2008 and 2012. The present study examined males aged ≥18 years from northwest rural China (n = 707). Data on current smoking and drinking status were collected. Logistic regression was used to estimate the individual and combined influences of smoking and alcohol consumption on lipid profile. Age, ethnic group, educational background, smoking (or alcohol consumption), waist circumference, body mass index, blood pressure and fasting blood glucose were adjusted as confounders. Total cholesterol (TC)/high-density lipoprotein cholesterol (HDL-C) ratio, triglycerides (TG)/HDL-C ratio, low-density lipoprotein cholesterol (LDL-C)/HDL-C ratio and visceral adiposity index (VAI) were significantly higher in smokers than in non-smokers, whereas HDL-C was lower in smokers. TG/HDL-C ratio, LDL-C/HDL-C ratio, TG, lipid accumulation product and VAI were significantly higher in drinkers than non-drinkers. After adjustment for confounders, significant relationships were observed between smoking status and any dyslipidemia, low HDL-C and high VAI (odds ratios [ORs]: 2.53 [95% confidence interval {CI}: 1.25-5.15], 6.13 [95% CI: 2.84-13.25] and 4.39 [95% CI: 2.02-9.54], respectively). The OR for any dyslipidaemia was 1.94 (95% CI: 1.09-3.48) for subjects who smoke and drank alcohol compared with subjects who did not smoke or drink alcohol. Abnormalities in lipid profile are correlated with smoking and alcohol consumption, which calls for intervention strategies to prevent dyslipidaemia and control risk factors for cardiovascular disease. Copyright © 2018 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

Chemical composition, sources and secondary processes of aerosols in Baoji city of northwest China

Science.gov (United States)

Wang, Y. C.; Huang, R.-J.; Ni, H. Y.; Chen, Y.; Wang, Q. Y.; Li, G. H.; Tie, X. X.; Shen, Z. X.; Huang, Y.; Liu, S. X.; Dong, W. M.; Xue, P.; Fröhlich, R.; Canonaco, F.; Elser, M.; Daellenbach, K. R.; Bozzetti, C.; El Haddad, I.; Prévôt, A. S. H.; Canagaratna, M. R.; Worsnop, D. R.; Cao, J. J.

2017-06-01

Particulate air pollution is a severe environmental problem in China, affecting visibility, air quality, climate and human health. However, previous studies focus mainly on large cities such as Beijing, Shanghai, and Guangzhou. In this study, an Aerodyne Aerosol Chemical Speciation Monitor was deployed in Baoji, a middle size inland city in northwest China from 26 February to 27 March 2014. The non-refractory submicron aerosol (NR-PM1) was dominated by organics (55%), followed by sulfate (16%), nitrate (15%), ammonium (11%) and chloride (3%). A source apportionment of the organic aerosol (OA) was performed with the Sofi (Source Finder) interface of ME-2 (Multilinear Engine), and six main sources/factors were identified and classified as hydrocarbon-like OA (HOA), cooking OA (COA), biomass burning OA (BBOA), coal combustion OA (CCOA), less oxidized oxygenated OA (LO-OOA) and more oxidized oxygenated OA (MO-OOA), which contributed 20%, 14%, 13%, 9%, 23% and 21% of total OA, respectively. The contribution of secondary components shows increasing trends from clean days to polluted days, indicating the importance of secondary aerosol formation processes in driving particulate air pollution. The formation of LO-OOA and MO-OOA is mainly driven by photochemical reactions, but significantly influenced by aqueous-phase chemistry during periods of low atmospheric oxidative capacity.

Evidence of climate change impact on stream low flow from the tropical mountain rainforest watershed in Hainan Island, China

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Z. Zhou; Y. Ouyang; Z. Qiu; G. Zhou; M. Lin; Y. Li

2017-01-01

Stream low flow estimates are central to assessing climate change impact, water resource management, and ecosystem restoration. This study investigated the impacts of climate change upon stream low flows from a rainforest watershed in Jianfengling (JFL) Mountain, Hainan Island, China, using the low flow selection method as well as the frequency and probability analysis...

The Implication of Climate Signal for Precipitation in the Heihe River Basin, Northwest China

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Fei Wang

2016-01-01

Full Text Available This paper studies the stochastic dynamic variability of precipitation, for the upper, middle, and lower reaches of the Heihe River basin in Northwest China, by employing Mann-Kendall statistic, Pettitt test, and wavelet transform methods. The possible associations with three prominent climatic patterns, El Niño-Southern Oscillation (ENSO, Artic Oscillation (AO, and Indian Ocean Dipole (IOD, are examined by using multiscale wavelet coherence method. No significant trend is identified for the interannual precipitation variability. However, about 2-year significant variability is detected for the lower reach of the Heihe River basin, and this dominating precipitation variability is essentially depicted by AO. The possible influences of ENSO are exerted on long-term timescale, 8–16 years. The obtained knowledge is helpful for the predications of extreme hydroclimatological events and better reservoir operations for regional water resources.

Roles of scholars in the practice of combating-desertification: a case study in northwest China.

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Yang, Lihua; Lan, Zhiyong; Wu, Jianguo

2010-08-01

This study investigated the perceived importance of scholars' participation in combating-desertification programs in northwest China and analyzed the underlying factors and mechanisms. Our results show that, while various experts, professors, and researchers have participated in combating-desertification programs, their actions were often not effective. Only those scholars who understood the local situations adequately had important and positive impacts. These scholars served as information brokers between the governments and other stakeholders, entrepreneurial activity organizers for farmers, governmental representatives, or advocators for local affairs themselves. They played indispensible roles in facilitating efforts in combating desertification. The study also identified key factors that led to the success of scholars' participation in combating-desertification activities. Our findings have practical implications for improving the effectiveness of scholars' participation in land restoration and environmental management.

Sustainability of Water Resources in Arid Ecosystems: A View from Hei River Basin, China (Invited)

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Zheng, C.; Cheng, G.; Xiao, H.; Ma, R.

2009-12-01

The northwest of China is characterized by an arid climate and fragile ecosystems. With irrigated agriculture, the region is a prolific producer of cotton, wheat, and maize with some of the highest output per acre in the country. The region is also rich in ore deposits, with the reserves of numerous minerals ranked at or near the top in the country. However, the sustainability of irrigated agriculture and economic development in the region is threaten by severe eco-environmental problems resulting from both global changes and human activities, such as desertification, salinization, groundwater depletion, and dust storms. All these problems are a direct consequence of water scarcity. As global warming accelerates and rapid economic growth continues, the water shortage crisis is expected to worsen. To improve the bleak outlook for the health of ecosystem and environment in northwest China, the Chinese government has invested heavily in ecosystem restoration and watershed management in recent years. However, the effectiveness of such measures and actions depends on scientific understanding of the complex interplays among ecological, hydrological and socioeconomic factors. This presentation is intended to provide an overview of a major new research initiative supported by the National Natural Science Foundation of China to study the integration of ecological principles, hydrological processes and socioeconomic considerations toward more sustainable exploitation of surface water and groundwater resources in the Hei River Basin in northwest China. The Hei River Basin is an inland watershed located at the center of the arid region in East Asia, stretching from Qilianshan Mountains in the south to the desert in the north bordering China’s Inner Mongolia Autonomous Region and Mongolia. The total area of Hei River Basin is approximately 130,000 km2. The research initiative builds on existing research infrastructure and ecohydrological data and seeks to reveal complex

Simulating Crop Evapotranspiration Response under Different Planting Scenarios by Modified SWAT Model in an Irrigation District, Northwest China.

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Liu, Xin; Wang, Sufen; Xue, Han; Singh, Vijay P

2015-01-01

Modelling crop evapotranspiration (ET) response to different planting scenarios in an irrigation district plays a significant role in optimizing crop planting patterns, resolving agricultural water scarcity and facilitating the sustainable use of water resources. In this study, the SWAT model was improved by transforming the evapotranspiration module. Then, the improved model was applied in Qingyuan Irrigation District of northwest China as a case study. Land use, soil, meteorology, irrigation scheduling and crop coefficient were considered as input data, and the irrigation district was divided into subdivisions based on the DEM and local canal systems. On the basis of model calibration and verification, the improved model showed better simulation efficiency than did the original model. Therefore, the improved model was used to simulate the crop evapotranspiration response under different planting scenarios in the irrigation district. Results indicated that crop evapotranspiration decreased by 2.94% and 6.01% under the scenarios of reducing the planting proportion of spring wheat (scenario 1) and summer maize (scenario 2) by keeping the total cultivated area unchanged. However, the total net output values presented an opposite trend under different scenarios. The values decreased by 3.28% under scenario 1, while it increased by 7.79% under scenario 2, compared with the current situation. This study presents a novel method to estimate crop evapotranspiration response under different planting scenarios using the SWAT model, and makes recommendations for strategic agricultural water management planning for the rational utilization of water resources and development of local economy by studying the impact of planting scenario changes on crop evapotranspiration and output values in the irrigation district of northwest China.

Phylogeographic patterns of Lygus pratensis (Hemiptera: Miridae): Evidence for weak genetic structure and recent expansion in northwest China.

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Zhang, Li-Juan; Cai, Wan-Zhi; Luo, Jun-Yu; Zhang, Shuai; Wang, Chun-Yi; Lv, Li-Min; Zhu, Xiang-Zhen; Wang, Li; Cui, Jin-Jie

2017-01-01

Lygus pratensis (L.) is an important cotton pest in China, especially in the northwest region. Nymphs and adults cause serious quality and yield losses. However, the genetic structure and geographic distribution of L. pratensis is not well known. We analyzed genetic diversity, geographical structure, gene flow, and population dynamics of L. pratensis in northwest China using mitochondrial and nuclear sequence datasets to study phylogeographical patterns and demographic history. L. pratensis (n = 286) were collected at sites across an area spanning 2,180,000 km2, including the Xinjiang and Gansu-Ningxia regions. Populations in the two regions could be distinguished based on mitochondrial criteria but the overall genetic structure was weak. The nuclear dataset revealed a lack of diagnostic genetic structure across sample areas. Phylogenetic analysis indicated a lack of population level monophyly that may have been caused by incomplete lineage sorting. The Mantel test showed a significant correlation between genetic and geographic distances among the populations based on the mtDNA data. However the nuclear dataset did not show significant correlation. A high level of gene flow among populations was indicated by migration analysis; human activities may have also facilitated insect movement. The availability of irrigation water and ample cotton hosts makes the Xinjiang region well suited for L. pratensis reproduction. Bayesian skyline plot analysis, star-shaped network, and neutrality tests all indicated that L. pratensis has experienced recent population expansion. Climatic changes and extensive areas occupied by host plants have led to population expansion of L. pratensis. In conclusion, the present distribution and phylogeographic pattern of L. pratensis was influenced by climate, human activities, and availability of plant hosts.

Simulating Crop Evapotranspiration Response under Different Planting Scenarios by Modified SWAT Model in an Irrigation District, Northwest China.

Directory of Open Access Journals (Sweden)

Xin Liu

Full Text Available Modelling crop evapotranspiration (ET response to different planting scenarios in an irrigation district plays a significant role in optimizing crop planting patterns, resolving agricultural water scarcity and facilitating the sustainable use of water resources. In this study, the SWAT model was improved by transforming the evapotranspiration module. Then, the improved model was applied in Qingyuan Irrigation District of northwest China as a case study. Land use, soil, meteorology, irrigation scheduling and crop coefficient were considered as input data, and the irrigation district was divided into subdivisions based on the DEM and local canal systems. On the basis of model calibration and verification, the improved model showed better simulation efficiency than did the original model. Therefore, the improved model was used to simulate the crop evapotranspiration response under different planting scenarios in the irrigation district. Results indicated that crop evapotranspiration decreased by 2.94% and 6.01% under the scenarios of reducing the planting proportion of spring wheat (scenario 1 and summer maize (scenario 2 by keeping the total cultivated area unchanged. However, the total net output values presented an opposite trend under different scenarios. The values decreased by 3.28% under scenario 1, while it increased by 7.79% under scenario 2, compared with the current situation. This study presents a novel method to estimate crop evapotranspiration response under different planting scenarios using the SWAT model, and makes recommendations for strategic agricultural water management planning for the rational utilization of water resources and development of local economy by studying the impact of planting scenario changes on crop evapotranspiration and output values in the irrigation district of northwest China.

Linear and nonlinear characteristics of the runoff response to regional climate factors in the Qira River basin, Xinjiang, Northwest China

Directory of Open Access Journals (Sweden)

Jie Xue

2015-07-01

Full Text Available The inland river watersheds of arid Northwest China represent an example of how, in recent times, climatic warming has increased the complexity of Earth’s hydrological processes. In the present study, the linear and nonlinear characteristics of the runoff response to temperature and precipitation were investigated in the Qira River basin, located on the northern slope of the Kunlun Mountains. The results showed that average temperature on annual and seasonal scales has displayed a significantly increasing trend, but this has not been reflected in accumulated precipitation and runoff. Using path analysis, a positive link between precipitation and runoff was found both annually and in the summer season. Conversely, it was found that the impact of temperature on runoff has been negative since the 1960s, attributable to higher evaporation and infiltration in the Qira River basin. Over the past 50 years, abrupt changes in annual temperature, precipitation and runoff occurred in 1997, 1987 and 1995, respectively. Combined with analysis using the correlation dimension method, it was found that the temperature, precipitation and runoff, both annually and seasonally, possessed chaotic dynamic characteristics, implying that complex hydro-climatic processes must be introduced into other variables within models to describe the dynamics. In addition, as determined via rescaled range analysis, a consistent annual and seasonal decreasing trend in runoff under increasing temperature and precipitation conditions in the future should be taken into account. This work may provide a theoretical perspective that can be applied to the proper use and management of oasis water resources in the lower reaches of river basins like that of the Qira River.

Allele frequencies of 18 autosomal STR loci in the Uyghur population living in Kashgar Prefecture, Northwest China.

Science.gov (United States)

Zhang, Jian; Li, Zhenghui; Mo, Xiaoting; Ma, Wenhua; Zhang, Hantao; Lin, Ziqing; Ye, Jian

2018-03-10

There is currently no large population data-based data set in Kashgar Prefecture Uyghur. The allele frequencies of 18 autosomal short tandem repeat (STR) loci included in the DNATyper™ 19 kit were evaluated in 2600 Uyghur individuals living in Kashgar Prefecture, Northwest China. The values of combined power of discrimination (CPD) and combined probability of exclusion (CPE) of all 18 autosomal STR loci were 0.99999999999999999998235 and 0.99999998670, respectively. Phylogenetic analyses revealed that the Uyghur population has a closer relationship with the Xinjiang-Kazakh, Inner Mongolia-Mongolian, and other three Uyghur populations. In addition, our results are consistent with the hypothesis that Uyghur population is an admixture of Eastern Asian and European populations.

Loess Thickness Variations Across the Loess Plateau of China

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Zhu, Yuanjun; Jia, Xiaoxu; Shao, Mingan

2018-01-01

The soil thickness is very important for investigating and modeling soil-water processes, especially on the Loess Plateau of China with its deep loess deposit and limited water resources. A digital elevation map (DEM) of the Loess Plateau and neighborhood analysis in ArcGIS software were used to generate a map of loess thickness, which was then validated by 162 observations across the plateau. The generated loess thickness map has a high resolution of 100 m × 100 m. The map indicates that loess is thick in the central part of the plateau and becomes gradually shallower in the southeast and northwest directions. The areas near mountains and river basins have the shallowest loess deposit. The mean loess thickness is the deepest in the zones with 400-600-mm precipitation and decreases gradually as precipitation varies beyond this range. Our validation indicates that the map just slightly overestimates loess thickness and is reliable. The loess thickness is mostly between 0 and 350 m in the Loess Plateau region. The calculated mean loess thickness is 105.7 m, with the calibrated value being 92.2 m over the plateau exclusive of the mountain areas. Our findings provide very basic data of loess thickness and demonstrate great progress in mapping the loess thickness distribution for the plateau, which are valuable for a better study of soil-water processes and for more accurate estimations of soil water, carbon, and solute reservoirs in the Loess Plateau of China.

Floristic analysis of the wanda mountain in north eastern china

International Nuclear Information System (INIS)

Wang, H.; Xu, L.; Zhang, Z.

2016-01-01

The plants of the Wanda Mountain area were investigated between 2009 to 2013. The results show that Wanda Mountain has 95 families of seed plants distributed in 334 genera and 705 species. A geographical component analysis shows that in addition to a small number of cosmopolitan species, cold, temperate and tropical species account for 14.9%, 77.3% and 4.4% of the total species, respectively, indicating that the flora of the Wanda Mountains exhibits a significant temperate nature and includes a small number of tropical components and certain cold components. In addition, the Wanda Mountains show a remarkable level of endemism and are geographically related to other regions in East Asia, particularly Japan. Furthermore, the Wanda Mountains present a complicated species composition, with a total of 14 distribution patterns and 10 variants. The coefficient of similarity between the flora of the Wanda Mountain area and the flora of the Changbai Mountain area is 43.1%, and the coefficient of similarity between the flora of the Wanda Mountain area and the flora of the Lesser Xingan Mountain area is 49.2%, indicating that the plants of the Wanda Mountain area are more common to those of the Lesser Xingan Mountain area. (author)

Patrilineal background of the She minority population from Chaoshan Fenghuang Mountain, an isolated mountain region, in China.

Science.gov (United States)

Liu, Shuhui; Chen, Guangcan; Huang, Haihua; Lin, Wenting; Guo, Dan; Zhao, Shukun; Tian, Dongping; Su, Min

2017-07-01

The She ethnic minority population is distributed in southern China. The origin of the She population has been controversial. The purpose of this work was to investigate the genomic diversity of She. The Chaoshan She population living in the Chaoshan Fenghuang mountain is a relatively isolated population. We detected 14 Y chromosome biallelic markers (Y-SNPs) and 6 Y chromosome short tandem repeat (Y-STR) loci in Chaoshan She people. Y-SNP analysis showed the Chaoshan She was closely related to the Chaoshan Hakka, Chaoshanese, Tujia and Gaoshan national minority. Compared with the Fujian She, the Chaoshan She maintained a more southern native genetic structure. Y-STR analysis revealed the Chaoshan She population was more closely related to the Hakka population than the other Hans. We concluded the Chaoshan She population had a closer genetic relationship with the southern national minority and Hakka Han and it may be representative of She ancestors' patrilineal genetic structure. Copyright © 2017 Elsevier Inc. All rights reserved.

[Estimation of carbonaceous gases emission from forest fires in Xiao Xing'an Mountains of Northeast China in 1953-2011].

Science.gov (United States)

Hu, Hai-Qing; Luo, Bi-Zhen; Wei, Shu-Jing; Sun, Long; Wei, Shu-Wei; Wen, Zheng-Min

2013-11-01

Based on the forest resources investigation data and the forest fire inventory in 1953-2011, in combining with our field research in burned areas and our laboratory experiments, this paper estimated the carbonaceous gases carbon dioxide (CO2), carbon monoxide (CO), methane (CH4), and nonmethane hydrocarbons (NMHC) emission from the forest fires in Xiao Xing' an Mountains of Heilongjiang Province, Northeast China in 1953-2011. The total carbon emission from the forest fires in the Xiao Xing'an Mountains in 1953-2011 was 1.12 x 10(7) t, and the annual emission was averagely 1.90 x10(5) t, accounting for 1.7% of the annual average total carbon emission from the forest fires in China. The emission of CO2, CO, CH4, and NMHC was 3.39 x 10(7), 1.94 x 10(5), 1.09 x 10(5), and 7.46 x 10(4) t, respectively, and the corresponding annual average emission was 5.74 x 10(5), 3.29 x 10(4), 1.85 x 10(3), and 1.27 x 10(3) t, accounting for 1.4%, 1.2%, 1.7%, and 1.1% of the annual carbonaceous gases emitted from the forest fires in China, respectively. The combustion efficiency and the carbon emission per unit burned area of different forest types decreased in order of coniferous forest > broad-leaved forest > coniferous broadleaved mixed forest. Some rational forest fire management measures were put forward.

Runoff and soil erosion of field plots in a subtropical mountainous region of China

Science.gov (United States)

Fang, N. F.; Wang, L.; Shi, Z. H.

2017-09-01

Anthropogenic pressure coupled with strong precipitation events and a mountainous landscape have led to serious soil erosion and associated problems in the subtropical climate zone of China. This study analyzes 1576 rainfall-runoff-soil loss events at 36 experimental plots (a total of 148 plot-years of data) under a wide range of conditions in subtropical mountainous areas of China where slope farming is commonly practiced. The plots, which have standardized dimensions, represent five common types of land use and have four different slopes. Event-based analyses show that almost half of the total rainfall caused soil erosion in the study area. The dominant factor controlling the runoff coefficient is the slope gradient rather than the land use type. The maximum soil lossfor crop plots under steep tillage (35°) is 5004 t km-2 for a single event. Among the common local crops, the average soil loss values increase in the following order: buckwheat soil loss increase in the following order: red clover soil loss is caused by a small number of extreme events. The annual average soil loss of the 44 plots ranges from 19 to 4090 t km-2 year-1. The annual soil loss of plots of different land use types decrease in the following order: bare land (1533 t km-2 year-1) > cropland (1179 t km-2 year-1) > terraced cropland (1083 t km-2 year-1) > orchard land (1020 t km-2 year-1) > grassland (762 t km-2 year-1) > terraced orchard land (297 t km-2 year-1) > forest and grassland (281 t km-2 year-1).

Aeromagnetic map of northwest Utah and adjacent parts of Nevada and Idaho

Science.gov (United States)

Langenheim, Victoria

2016-01-01

Two aeromagnetic surveys were flown to promote further understanding of the geology and structure in northwest Utah and adjacent parts of Nevada and Idaho by serving as a basis for geophysical interpretations and by supporting geological mapping, water and mineral resource investigations, and other topical studies. Although this area is in general sparsely populated, (except for cities and towns along the Wasatch Front such as Ogden and Brigham City), it encompasses metamorphic core complexes in the Grouse Creek and Raft River Mountains (figure 1) of interest to earth scientists studying Cenozoic extension. The region was shaken in 1909 and 1934 by M6+ earthquakes east of the Hansel Mountains (Doser, 1989; Arabasz and others, 1994); damage from the 1934 earthquake occurred as far east as Logan, Utah (http:// www.seis.utah.edu/lqthreat/nehrp_htm/1934hans/n1934ha1. shtml#urbse). The presence of Quaternary shield volcanoes and bimodal Pleistocene volcanism in Curlew Valley (Miller and others, 1995; Felger and others, 2016) as well as relatively high temperature gradients encountered in the Indian Cove drillhole in the north arm of Great Salt Lake (Blackett and others, 2014) may indicate some potential for geothermal energy development in the area (Miller and others, 1995). The area also hosts four significant mining districts, in the northern Pilot Range, the Goose Creek Mountains in the northwest corner of the map, the southern end of the Promontory Mountains, and the southwest part of the Raft River Mountains, although production notably waned after World War II (Doelling, 1980). Other prospects of interest include those in the southern Grouse Creek Mountains, Silver Island, and the northern Newfoundland Mountains.Large areas of northwest Utah are covered by young, surficial deposits or by Great Salt Lake or are down-dropped into deep Cenozoic basins, making extrapolation of bedrock geology from widely spaced exposures difficult or tenuous (figure 1). Local spatial

Petrogenesis of Cretaceous shoshonitic rocks in the northern Wuyi Mountains, South China: A result of the roll-back of a flat-slab?

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Li, Wu-Xian; Li, Xian-Hua; Wang, Xuan-Ce; Yang, Dong-Sheng

2017-09-01

Potassic magmatism is commonly linked to post-/late-orogenic environments, such as foundering or convection thinning of continental lithosphere. Their petrogenesis is crucial for constraining the chemical and physical properties of the remnant sub-continental lithospheric mantle. Here we report new SHRIMP zircon U-Pb ages, whole rock geochemical results and Sr-Nd and zircon Hf isotope data from four potassic plutons (the Da'an, Yingcheng, Zixi and Honggong plutons) in the northern Wuyi Mountains, South China. SHRIMP U-Pb zircon analyses indicate that these potassic rocks formed at 139-126 Ma. They are characterized by high SiO2 (56-73%) and K2O (3.8-6.7%), with a K2O/Na2O ratio of 2.18-2.04, plotting within the field of high-SiO2 shoshonites. Their ISr and εNd(t) values vary from 0.7077 to 0.7162 and - 5.66 to - 10.52, respectively. The initial zircon εHf(t) values range from 2.3 to - 13.1, corresponding to TDM modal ages between 707 and 1330 Ma. These geochemical and isotope characteristics indicate that these shoshonites derived from a subduction-modified ancient subcontinental lithospheric mantle, and then underwent significantly fractional crystallization of K-feldspar, plagioclase, and accessory minerals, such as apatite and Fe-Ti oxides during magma ascent. We interpret that asthenospheric mantle upwelling (caused by eastward roll-back of a flat-slab?) triggered partial melting of the metasomatized lithospheric mantle to result in the Early Cretaceous shoshonitic magmatism in the northern Wuyi Mountains. An integration of our new results with compiled data from the interior of the South China Block reveals that the arc-like geochemical signature is confined to the Wuyi Mountains region, but becomes little or even invisible toward inland in South China. This implies that the far-field effects of the early Mesozoic subduction only reached the Wuyi Mountains, ca. 500 km away from the trench, consistent with flat or shallow subduction models.

Impact of region on the composition of milk fatty acids in China.

Science.gov (United States)

Yang, Yongxin; Wang, Jiaqi; Yuan, Tingjie; Bu, Dengpan; Yang, Jinhui; Zhou, Lingyun; Sun, Peng; Zhang, Juanxia

2013-08-30

Milk composition and its fatty acid profile have received much attention with respect to improving human health. However, limited work has been conducted to assess the composition of milk fat in China, which is the third largest producer of milk in the world. In this study the effects of geographical region and seasonal changes (spring and summer) on the fatty acid composition of milk samples collected from six Chinese farms were investigated. Milk fat and protein contents, as well as some individual fatty acids and five fatty acid groups, were found to be unaffected by season, but they did show significant differences by geographical region. Levels of milk cis-9, trans-11 conjugated linoleic acid decreased in summer and increased in spring, increased in north (Hohhot), northeast (Harbin), north centre (Beijing) and northwest (Xi'an) China and decreased in far northwest (Urumqi) and east (Chuzhou) China. Monounsaturated fatty acids increased in east and northwest China and decreased in northeast China, while polyunsaturated fatty acids increased in far northwest and north centre China and decreased in northeast China. This study provides relevent information that contributes to the understanding of parameters affecting variability of milk fatty acid profiles. © 2012 Society of Chemical Industry.

Area selection for a geological repository of high level radioactive waste in China

International Nuclear Information System (INIS)

Jin Yuanxin; Wang Ju; Chen Weiming; Guo Yonghai; Su Rui; Zhao Honggang; Xu Guoqing

2012-01-01

China started research on HLW disposal in 1985 and 6 areas, including Northwest, Southwest, East China, South China, Inner Mongolia and Xinjiang area, are selected. The results show that the Northwest area has obvious comprehensive advantages, which can be considered as the first area for site selection, while site characterization and comparison research in the area should be continued. (authors)

Land surface temperature retrieval from MODIS and VIRR data in northwest China

International Nuclear Information System (INIS)

Wang, L J; Zuo, H C; Ren, P C; Qiang, B

2014-01-01

By using the Gulang Heterogeneous Underlying Surface Layer Experiment (GHUSLE) data, the accuracy of land surface temperature (LST) in Northwest China retrieved by the Moderate-Resolution Imaging Spectroradiometer(MODIS) and Visible and InfraRed Radiometer(VIRR) data is verified. Furthermore, a new LST algorithm for heterogeneous underlying surface is developed and the LST retrieved by the two remote sensing data using three algorithms are compared with the observed data. Results suggest that the new algorithm is the best one in the case of heterogeneous underlying surface, Kerr algorithm accuracy is not satisfying and Becker algorithm is ranked just ahead Kerr algorithm. Especially, the differences in retrieval accuracy among them are more obvious when using the VIRR data. Compared with the observed LST, the root mean square errors of the LST retrieved by MODIS and VIRR data are the least when using the new algorithm, the specific values are 2.55 K and 3.78 K, respectively. The LST retrieved by MODIS data are closer to observed values and higher than its counterpart retrieved by VIRR data. When the new LST retrieval algorithm used, the LST retrieved by MODIS and VIRR data are the closest

Effects of Urbanization on Landscape Patterns in a Mountainous Area: A Case Study in the Mentougou District, Beijing, China

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Yang Yi

2016-11-01

Full Text Available We explored the process of urbanization in a mountainous area to seek a sustainable urbanization strategy. Previous urbanization research has mainly focused on flat terrain and coastal areas, and urbanization in mountainous areas remains poorly understood. This study integrated geographic information systems, remote sensing, and statistical analysis to quantify landscape patterns dynamics in response to urbanization, with a case study of Mentougou District in Beijing, China from 1985 to 2014. We found that the total built-up area increased along with the population and economic indicators. The built-up area increased by one-third over the study period, with 73.38% of the increase from converted cropland and 12.22% from converted orchard. The urban expansion area was concentrated in the plain sub-region (<200 m elevation, comprising 68.85% of the expansion area. The landscape patterns varied over this period. For the whole region, the low mountain sub-region and the high mountain sub-region, landscape patterns gradually became more heterogeneous and fragmented, but they showed the opposite trend in the plain sub-region. None of the urbanization indicators (population, economic and built-up land area were significantly correlated with landscape metrics for the whole region, but they were significantly correlated in the plain sub-region. The impacts of urbanization on landscape patterns were mainly focused on the plain sub-region, and the effects in the low mountain and high mountain sub-regions were weak. Future urban development in mountainous areas should focus on the protection of cropland and local industries as part of a sustainable development strategy for the whole region.

Review of the comb-tailed spider genus Hahnia C.L. Koch 1841 (Hahniidae) from Gaoligong Mountains in Yunnan, China.

Science.gov (United States)

Huang, Gui-Qiang; Zhang, Zhi-Sheng; Liu, Ying-Hong

2017-11-08

Gaoligong Mountains in Yunnan, China are famous for the biodiversity and are part of Indo-Burmese hotspot. We present a review on the comb-tailed spider genus Hahnia C.L. Koch 1841 based on newly collected specimens. Four new species of Hahnia are described: H. biapophysis sp. nov. (male), H. dongi sp. nov. (male), H. subsaccata sp. nov. (male, female) and H. wangi sp. nov. (male, female). Two additional known species are redescribed: H. himalayaensis Hu & Zhang, 1990 and H. musica Brignoli, 1978. Hahnia musica previously known from Bhutan is recorded from China for the first time. Photos of habitus and genitalia of all species and additionally illustrations of new species are given.

A Study of the Time–Space Evolution Characteristics of Urban–Rural Integration Development in a Mountainous Area Based on ESDA-GIS: The Case of the Qinling-Daba Mountains in China

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Xin Wu

2016-10-01

Full Text Available The multi-index comprehensive evaluation method is used in this paper to estimate the urban–rural integration development level of the Qinling-Daba Mountains in China and build an evaluation index system that is composed by five subsystems and 18 basic indexes. The integration of the indexes is conducted through linear weight sum method and the weight of each index is determined through analytic network process to get the urban–rural integration development coordination indexes of each county in the Qinling-Daba Mountains. Meanwhile, the time–space evolution characteristic of urban–rural integration development in the Qinling-Daba Mountains in the past 10 years is studied through exploratory spatial data analysis and GIS technology. The results indicate that urban–rural integration displays a spatial imbalance, with a situation of polarization, i.e., high–level counties gathering with each other; the spatial aggregation rule of west–high, east–low is coupled with land conditions, industrial activity, and the transportation situation to affect the urban–rural development. Finally, we propose that development priorities should be circular industry, eco-agriculture, and tourism to accelerate urban–rural development and work towards a comprehensive modern transportation system and other infrastructure in the Qinling-Daba Mountains.

Species diversity and drivers of arbuscular mycorrhizal fungal communities in a semi-arid mountain in China

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He Zhao

2017-12-01

Full Text Available Arbuscular mycorrhizal fungi (AMF play an essential role in complex ecosystems. However, the species diversity and composition of AMF communities remain unclear in semi-arid mountains. Further, it is not well understood if the characteristics of AMF community assemblies differ for different habitat types, e.g., agricultural arable land, artificial forest land, natural grassland, and bush/wood land. Here, using the high-throughput technology by Illumina sequencing on the MiSeq platform, we explored the species diversity and composition of soil AMF communities among different habitat types in a semi-arid mountain (Taihang Mountain, Mid-western region of China. Then, we analyzed the effect of nutrient composition and soil texture on AMF community assembly. Our results showed that members of the Glomus genera were predominated in all soil types. The distance-based redundancy analysis indicated that the content of water, available phosphorus, and available potassium were the most crucial geochemical factors that significantly affected AMF communities (p < 0.05. The analysis of the soil texture confirmed that AMF diversity was negatively correlated with soil clay content. The comparison of AMF diversity among the various habitat types revealed that the artificial forest land had the lowest AMF diversity in comparison with other land types. Our findings suggest that there were differences in species diversity and composition of soil AMF communities among different habitat types. These findings shed new light on the characteristics of community structure and drivers of community assembly in AMF in semi-arid mountains, and point to the potential importance of different habitat types on AMF communities.

An Andean-type retro-arc foreland system beneath northwest South China revealed by SINOPROBE profiling

Science.gov (United States)

Li, Jianhua; Dong, Shuwen; Cawood, Peter A.; Zhao, Guochun; Johnston, Stephen T.; Zhang, Yueqiao; Xin, Yujia

2018-05-01

In the Mesozoic, South China was situated along the convergent margin between the Asian and Pacific plates, providing an excellent laboratory to understand the interactions between deformation, sedimentation and magmatism in a retroarc environment. The crustal architecture of northwest South China is displayed along the ∼600-km-long SINOPROBE deep seismic reflection profiles and reveals from east to west: (1) highly folded and truncated reflectors in the upper crust of the Yangtze Fold Zone, which correspond to thin- and thick-skinned thrust systems, and document large-scale intraplate structural imbrication and shortening; (2) a crustal-scale flat-ramp-flat structure, termed the Main Yangtze decollement, which forms a weak, viscous layer to accommodate strain decoupling and material transport in the thin- and thick-skinned systems; and (3) nearly flat-lying reflectors in the Sichuan Basin, which support interpretation of the basin as a weakly deformed depocentre. The Yangtze Fold Zone and the Sichuan Basin represent a retro-arc foreland basin system that is >800 km away from the continental-margin magmatic arc. We suggest that tectonic processes across the arc and retro-arc systems, including arc magma flare-up, basin sedimentation, retroarc thrust propagation, lithosphere underthrusting, root foundering, and extension-related magmatism were interrelated and governed mass transfer. Age data and geological relations link the tectonic processes to evolving geodynamics of the subducting Paleo-Pacific plate.

The status of Yucca Mountain site characterization activities

International Nuclear Information System (INIS)

Gertz, Carl P.; Larkin, Erin L.; Hamner, Melissa

1992-01-01

The U.S. Department of Energy (DOE) Office of Civilian Radioactive Waste Management (OCRWM) is continuing its studies to determine if Yucca Mountain, Nevada, can safely isolate high-level nuclear waste for the next ten thousand years. As mandated by Congress in 1987, DOE is studying the rocks, the climate, and the water table at Yucca Mountain to ensure that the site is suitable before building a repository adopt 305 meters below the surface. Yucca Mountain, located 160.9 kilometers northwest of Las Vegas, lies on the western edge of the Nevada Test Site. Nevada and DOE have been in litigation over environmental permits needed to conduct studies, but recent court decisions have allowed limited new work to begin. This paper will examine progress made on the Yucca Mountain Site Characterization Project (YMP) during 1991 and continuing into 1992, discuss the complex legal issues and describe new site drilling work. Design work on the underground exploratory studies facility (ESF) will also be discussed. (author)

Remotely Sensed Estimation of Net Primary Productivity (NPP and Its Spatial and Temporal Variations in the Greater Khingan Mountain Region, China

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Qiang Zhu

2017-07-01

Full Text Available We improved the CASA model based on differences in the types of land use, the values of the maximum light use efficiency, and the calculation methods of solar radiation. Then, the parameters of the model were examined and recombined into 16 cases. We estimated the net primary productivity (NPP using the NDVI3g dataset, meteorological data, and vegetation classification data from the Greater Khingan Mountain region, China. We assessed the accuracy and temporal-spatial distribution characteristics of NPP in the Greater Khingan Mountain region from 1982 to 2013. Based on a comparison of the results of the 16 cases, we found that different values of maximum light use efficiency affect the estimation more than differences in the fraction of photosynthetically active radiation (FPAR. However, the FPARmax and the constant Tε2 values did not show marked effects. Different schemes were used to assess different model combinations. Models using a combination of parameters established by scholars from China and the United States produced different results and had large errors. These ideas are meaningful references for the estimation of NPP in other regions. The results reveal that the annual average NPP in the Greater Khingan Mountain region was 760 g C/m2·a in 1982–2013 and that the inter-annual fluctuations were not dramatic. The NPP estimation results of the 16 cases exhibit an increasing trend. In terms of the spatial distribution of the changes, the model indicated that the values in 75% of this area seldom or never increased. Prominent growth occurred in the areas of Taipingling, Genhe, and the Oroqen Autonomous Banner. Notably, NPP decreased in the southeastern region of the Greater Khingan Mountains, the Hulunbuir Pasture Land, and Holingol.

Seasonal habitat selection of the red deer (Cervus elaphus alxaicus in the Helan Mountains, China

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Mingming Zhang

2013-02-01

Full Text Available We studied the seasonal habitat selection of the red deer, Cervus elaphus alxaicus Bobrinskii & Flerov, 1935, in the Helan Mountains, China, from December 2007 to December 2008. Habitat selection varied widely by season. Seasonal movements between high and low elevations were attributed to changes in forage availability, alpine topography, the arid climate of the Helan Mountains, and potential competition with blue sheep, Pseudois nayaur (Hodgson, 1833. The use of vegetation types varied seasonally according to food availability and ambient temperature. Red deer used montane coniferous forest and alpine shrub and meadow zones distributed above 2,000 m and 3,000 m in summer, alpine shrub and meadows above 3,000 m in autumn, being restricted to lower elevation habitats in spring and winter. The winter habitat of C. elaphus alxaicus was dominated by Ulmus glaucescens Franch. and Juglans regia Linnaeus, deciduous trees, and differed from the habitats selected by other subspecies of red deer. Cervus elaphus alxaicus preferred habitats with abundant vegetation coverage to open habitats in winter, but the reverse pattern was observed in summer and autumn. Red deer preferred gentle slopes (<10° but the use of slope gradient categories varied seasonally. Red deer avoidance of human disturbance in the Helan Mountains varied significantly by season. Information on red deer habitat selection can help understand the factors affecting seasonal movements and also support decision making in the management and conservation of red deer and their habitats.

Study on site selection of cold chain logistics in northwest territories

Science.gov (United States)

Liu, Yubin; Ren, Zongwei

2017-08-01

In this research, we mainly studied the Site selection problem of cold chain logistics in northwest of China. In the first place, we counted the demands of cold chain products in northwest territories, and then classified it into the Site selection problem in five provinces in northwest territories(Xinjiang, Qinghai, Gansu, Ningxia, Shanxi); Next, we used the Center of gravity Method to select initial location; Finally, we established the location of distribution by using Analytic Hierarchy Process (AHP)and fuzzy comprehensive evaluation method. Comparing with the traditional method, this method not only considered the cost of transportation and distance, but also deliberated the physical condition, social environment and economics condition which associated with Site selection problem.

Onychiurid species from Wanda Mountains in China, with descriptions of two new species (Collembola, Onychiuridae)

Science.gov (United States)

Sun, Xin; Wu, Donghui

2014-01-01

Abstract A checklist of onychiurid species from the Wanda Mountains in China is presented. Eighteen species belonging to twelve genera have been found, including two new species. Bionychiurus qinglongensis sp. n. can be easily distinguished from other known species of the genus by the absence of pseudocelli on Th. I tergum and fewer number of vesicles in postantennal organ. Onychiurus heilongjiangensis sp. n. is diagnosed by pseudocellar formulae as 32/133/33352 dorsally and 3/011/31120 ventrally, parapseudocellar formula as 0/000/111001+1m, ratio of anal spine/unguis as 0.6, unguiculus without inner basal lamella, and male ventral organ absent. PMID:25147452

A closure study of aerosol optical properties at a regional background mountainous site in Eastern China

International Nuclear Information System (INIS)

Yuan, Liang; Yin, Yan; Xiao, Hui; Yu, Xingna; Hao, Jian; Chen, Kui

2016-01-01

There is a large uncertainty in evaluating the radiative forcing from aerosol–radiation and aerosol–cloud interactions due to the limited knowledge on aerosol properties. In-situ measurements of aerosol physical and chemical properties were carried out in 2012 at Mt. Huang (the Yellow Mountain), a continental background mountainous site in eastern China. An aerosol optical closure study was performed to verify the model outputs by using the measured aerosol optical properties, in which a spherical Mie model with assumptions of external and core–shell mixtures on the basis of a two-component optical aerosol model and high size-segregated element carbon (EC) ratio was applied. Although the spherical Mie model would underestimate the real scattering with increasing particle diameters, excellent agreement between the calculated and measured values was achieved with correlation coefficients above 0.98. Sensitivity experiments showed that the EC ratio had a negligible effect on the calculated scattering coefficient, but largely influenced the calculated absorption coefficient. The high size-segregated EC ratio averaged over the study period in the closure was enough to reconstruct the aerosol absorption coefficient in the Mie model, indicating EC size resolution was more important than time resolution in retrieving the absorption coefficient in the model. The uncertainties of calculated scattering and absorption coefficients due to the uncertainties of measurements and model assumptions yielded by a Monte Carlo simulation were ± 6% and ± 14% for external mixture and ± 9% and ± 31% for core–shell mixture, respectively. This study provided an insight into the inherent relationship between aerosol optical properties and physicochemical characteristics in eastern China, which could supplement the database of aerosol optical properties for background sites in eastern China and provide a method for regions with similar climate. - Highlights: • A spherical Mie

A closure study of aerosol optical properties at a regional background mountainous site in Eastern China

Energy Technology Data Exchange (ETDEWEB)

Yuan, Liang [Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Nanjing University of Information Science & Technology, Nanjing 210044 (China); Key Laboratory for Aerosol–Cloud–Precipitation of China Meteorological Administration, School of Atmospheric Physics, Nanjing University of Information Science and Technology, Nanjing 210044 (China); Yin, Yan, E-mail: yinyan@nuist.edu.cn [Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Nanjing University of Information Science & Technology, Nanjing 210044 (China); Key Laboratory for Aerosol–Cloud–Precipitation of China Meteorological Administration, School of Atmospheric Physics, Nanjing University of Information Science and Technology, Nanjing 210044 (China); Xiao, Hui [Key Laboratory for Aerosol–Cloud–Precipitation of China Meteorological Administration, School of Atmospheric Physics, Nanjing University of Information Science and Technology, Nanjing 210044 (China); Yu, Xingna [Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Nanjing University of Information Science & Technology, Nanjing 210044 (China); Key Laboratory for Aerosol–Cloud–Precipitation of China Meteorological Administration, School of Atmospheric Physics, Nanjing University of Information Science and Technology, Nanjing 210044 (China); Hao, Jian; Chen, Kui [Key Laboratory for Aerosol–Cloud–Precipitation of China Meteorological Administration, School of Atmospheric Physics, Nanjing University of Information Science and Technology, Nanjing 210044 (China); and others

2016-04-15

There is a large uncertainty in evaluating the radiative forcing from aerosol–radiation and aerosol–cloud interactions due to the limited knowledge on aerosol properties. In-situ measurements of aerosol physical and chemical properties were carried out in 2012 at Mt. Huang (the Yellow Mountain), a continental background mountainous site in eastern China. An aerosol optical closure study was performed to verify the model outputs by using the measured aerosol optical properties, in which a spherical Mie model with assumptions of external and core–shell mixtures on the basis of a two-component optical aerosol model and high size-segregated element carbon (EC) ratio was applied. Although the spherical Mie model would underestimate the real scattering with increasing particle diameters, excellent agreement between the calculated and measured values was achieved with correlation coefficients above 0.98. Sensitivity experiments showed that the EC ratio had a negligible effect on the calculated scattering coefficient, but largely influenced the calculated absorption coefficient. The high size-segregated EC ratio averaged over the study period in the closure was enough to reconstruct the aerosol absorption coefficient in the Mie model, indicating EC size resolution was more important than time resolution in retrieving the absorption coefficient in the model. The uncertainties of calculated scattering and absorption coefficients due to the uncertainties of measurements and model assumptions yielded by a Monte Carlo simulation were ± 6% and ± 14% for external mixture and ± 9% and ± 31% for core–shell mixture, respectively. This study provided an insight into the inherent relationship between aerosol optical properties and physicochemical characteristics in eastern China, which could supplement the database of aerosol optical properties for background sites in eastern China and provide a method for regions with similar climate. - Highlights: • A spherical Mie

Vertical zonation of soil fungal community structure in a Korean pine forest on Changbai Mountain, China.

Science.gov (United States)

Ping, Yuan; Han, Dongxue; Wang, Ning; Hu, Yanbo; Mu, Liqiang; Feng, Fujuan

2017-01-01

Changbai Mountain, with intact montane vertical vegetation belts, is located at a sensitive area of global climate change and a central distribution area of Korean pine forest. Broad-leaved Korean pine mixed forest (Pinus koraiensis as an edificator) is the most representative zonal climax vegetation in the humid region of northeastern China; their vertical zonation is the most intact and representative on Changbai Mountain. In this study, we analyzed the composition and diversity of soil fungal communities in the Korean pine forest on Changbai Mountain at elevations ranging from 699 to 1177 m using Illumina High-throughput sequencing. We obtained a total 186,663 optimized sequences, with an average length of 268.81 bp. We found soil fungal diversity index was decreased with increasing elevation from 699 to 937 m and began to rise after reaching 1044 m; the richness and evenness indices were decreased with an increase in elevation. Soil fungal compositions at the phylum, class and genus levels varied significantly at different elevations, but with the same dominant fungi. Beta-diversity analysis indicated that the similarity of fungal communities decreased with an increased vertical distance between the sample plots, showing a distance-decay relationship. Variation partition analysis showed that geographic distance (mainly elevation gradient) only explained 20.53 % of the total variation of fungal community structure, while soil physicochemical factors explained 69.78 %.

Application of snowmelt runoff model (SRM in mountainous watersheds: A review

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Shalamu Abudu

2012-06-01

Full Text Available The snowmelt runoff model (SRM has been widely used in simulation and forecast of streamflow in snow-dominated mountainous basins around the world. This paper presents an overall review of worldwide applications of SRM in mountainous watersheds, particularly in data-sparse watersheds of northwestern China. Issues related to proper selection of input climate variables and parameters, and determination of the snow cover area (SCA using remote sensing data in snowmelt runoff modeling are discussed through extensive review of literature. Preliminary applications of SRM in northwestern China have shown that the model accuracies are relatively acceptable although most of the watersheds lack measured hydro-meteorological data. Future research could explore the feasibility of modeling snowmelt runoff in data-sparse mountainous watersheds in northwestern China by utilizing snow and glacier cover remote sensing data, geographic information system (GIS tools, field measurements, and innovative ways of model parameterization.

HYDROLOGIC CHARACTERISTICS OF FAULTS AT YUCCA MOUNTAIN, NEVADA

International Nuclear Information System (INIS)

R.P. Dickerson

2000-01-01

Yucca Mountain comprises a series of north-trending ridges composed of tuffs within the southwest Nevada volcanic field, 120 km northwest of Las Vegas, Nevada. These ridges are formed of east-dipping blocks of interbedded welded and nonwelded tuff that are offset along steep, mostly west-dipping faults that have tens to hundreds of meters of vertical separation. Yucca Mountain is currently under study as a potential site for underground storage of high-level radioactive waste, with the principle goal being the safe isolation of the waste from the accessible environment. To this end, an understanding of the behavior of ground-water flow through the mountain in the unsaturated zone and beneath the mountain in the saturated zone is critical. The percolation of water through the mountain and into the ground-water flow system beneath the potential repository site is predicated on: (1) the amount of water available at the surface as a result of the climatic conditions, (2) the hydrogeologic characteristics of the volcanic strata that compose the mountain. and (3) the hydrogeologic characteristics of the structures, particularly fault zones and fracture networks, that disrupt these strata. This paper addresses the hydrogeologic characteristics of the fault zones at Yucca Mountain, focusing primarily on the central part of the mountain where the potential repository block is located

Groundwater Recharge and Flow Processes in Taihang Mountains, a Semi-humid Region, North China

Science.gov (United States)

Sakakibara, Koichi; Tsujimura, Maki; Song, Xianfang; Zhang, Jie

2015-04-01

Groundwater flow/recharge variations in time and space are crucial for effective water management especially in semi-arid and semi-humid regions. In order to reveal comprehensive groundwater flow/recharge processes in a catchment with a large topographical relief and seasonal hydrological variations, intensive field surveys were undertaken at 4 times in different seasons (June 2011, August 2012, November 2012, February 2014) in the Wangkuai watershed, Taihang mountains, which is a main groundwater recharge area of the North China Plain. The groundwater, spring, stream water and reservoir water were taken, and inorganic solute constituents and stable isotopes of oxygen-18 and deuterium were determined on all water samples. Also, the stream flow rate and the depth of groundwater table were observed. The stable isotopic compositions and inorganic solute constituents in the groundwater are depleted and shown similar values as those of the surface water at the mountain-plain transitional area. Additionally, the groundwater in the vicinity of the Wangkuai Reservoir presents clearly higher stable isotopic compositions and lower d-excess than those of the stream water, indicating the groundwater around the reservoir is affected by evaporation same as the Wangkuai Reservoir itself. Hence, the surface water in the mountain-plain transitional area and Wangkuai Reservoir are principal groundwater recharge sources. An inversion analysis and simple mixing model were applied in the Wangkuai watershed using stable isotopes of oxygen-18 and deuterium to construct a groundwater flow model. The model shows that multi-originated groundwater flows from upstream to downstream along topography with certain mixing. In addition, the groundwater recharge occurs dominantly at the altitude from 421 m to 953 m, and the groundwater recharge rate by the Wangkuai Reservoir is estimated to be 2.4 % of the total groundwater recharge in the Wangkuai watershed. Therefore, the stream water and

Integration of aspect and slope in snowmelt runoff modeling in a mountain watershed

Directory of Open Access Journals (Sweden)

Shalamu Abudu

2016-10-01

Full Text Available This study assessed the performances of the traditional temperature-index snowmelt runoff model (SRM and an SRM model with a finer zonation based on aspect and slope (SRM + AS model in a data-scarce mountain watershed in the Urumqi River Basin, in Northwest China. The proposed SRM + AS model was used to estimate the melt rate with the degree-day factor (DDF through the division of watershed elevation zones based on aspect and slope. The simulation results of the SRM + AS model were compared with those of the traditional SRM model to identify the improvements of the SRM + AS model's performance with consideration of topographic features of the watershed. The results show that the performance of the SRM + AS model has improved slightly compared to that of the SRM model. The coefficients of determination increased from 0.73, 0.69, and 0.79 with the SRM model to 0.76, 0.76, and 0.81 with the SRM + AS model during the simulation and validation periods in 2005, 2006, and 2007, respectively. The proposed SRM + AS model that considers aspect and slope can improve the accuracy of snowmelt runoff simulation compared to the traditional SRM model in mountain watersheds in arid regions by proper parameterization, careful input data selection, and data preparation.

Studying groundwater and surface water interactions using airborne remote sensing in Heihe River basin, northwest China

Science.gov (United States)

Liu, C.; Liu, J.; Hu, Y.; Zheng, C.

2015-05-01

Managing surface water and groundwater as a unified system is important for water resource exploitation and aquatic ecosystem conservation. The unified approach to water management needs accurate characterization of surface water and groundwater interactions. Temperature is a natural tracer for identifying surface water and groundwater interactions, and the use of remote sensing techniques facilitates basin-scale temperature measurement. This study focuses on the Heihe River basin, the second largest inland river basin in the arid and semi-arid northwest of China where surface water and groundwater undergoes dynamic exchanges. The spatially continuous river-surface temperature of the midstream section of the Heihe River was obtained by using an airborne pushbroom hyperspectral thermal sensor system. By using the hot spot analysis toolkit in the ArcGIS software, abnormally cold water zones were identified as indicators of the spatial pattern of groundwater discharge to the river.

Studying groundwater and surface water interactions using airborne remote sensing in Heihe River basin, northwest China

Directory of Open Access Journals (Sweden)

C. Liu

2015-05-01

Full Text Available Managing surface water and groundwater as a unified system is important for water resource exploitation and aquatic ecosystem conservation. The unified approach to water management needs accurate characterization of surface water and groundwater interactions. Temperature is a natural tracer for identifying surface water and groundwater interactions, and the use of remote sensing techniques facilitates basin-scale temperature measurement. This study focuses on the Heihe River basin, the second largest inland river basin in the arid and semi-arid northwest of China where surface water and groundwater undergoes dynamic exchanges. The spatially continuous river-surface temperature of the midstream section of the Heihe River was obtained by using an airborne pushbroom hyperspectral thermal sensor system. By using the hot spot analysis toolkit in the ArcGIS software, abnormally cold water zones were identified as indicators of the spatial pattern of groundwater discharge to the river.

[Climatic suitability of citrus in subtropical China].

Science.gov (United States)

Duan, Hai-Lai; Qian, Huai-Sui; Li, Ming-Xia; Du, Yao-Dong

2010-08-01

By applying the theories of ecological suitability and the methods of fuzzy mathematics, this paper established a climatic suitability model for citrus, calculated and evaluated the climatic suitability and its spatiotemporal differences for citrus production in subtropical China, and analyzed the climatic suitability of citrus at its different growth stages and the mean climatic suitability of citrus in different regions of subtropical China. The results showed that the citrus in subtropical China had a lower climatic suitability and a higher risk at its flower bud differentiation stage, budding stage, and fruit maturity stage, but a higher climatic suitability and a lower risk at other growth stages. Cold damage and summer drought were the key issues affecting the citrus production in subtropical China. The citrus temperature suitability represented a latitudinal zonal pattern, i. e., decreased with increasing latitude; its precipitation suitability was high in the line of "Sheyang-Napo", medium in the southeast of the line, low in the northwest of the line, and non in high mountainous area; while the sunlight suitability was in line with the actual duration of sunshine, namely, higher in high-latitude areas than in low-latitude areas, and higher in high-altitude areas than in plain areas. Limited by temperature factor, the climatic suitability was in accordance with temperature suitability, i. e., south parts had a higher suitability than north parts, basically representing latitudinal zonal pattern. From the analysis of the inter-annual changes of citrus climatic suitability, it could be seen that the citrus climatic suitability in subtropical China was decreasing, and had obvious regional differences, suggesting that climate change could bring about the changes in the regions suitable for citrus production and in the key stages of citrus growth.

Genomic analyses of metal resistance genes in three plant growth promoting bacteria of legume plants in Northwest mine tailings, China.

Science.gov (United States)

Xie, Pin; Hao, Xiuli; Herzberg, Martin; Luo, Yantao; Nies, Dietrich H; Wei, Gehong

2015-01-01

To better understand the diversity of metal resistance genetic determinant from microbes that survived at metal tailings in northwest of China, a highly elevated level of heavy metal containing region, genomic analyses was conducted using genome sequence of three native metal-resistant plant growth promoting bacteria (PGPB). It shows that: Mesorhizobium amorphae CCNWGS0123 contains metal transporters from P-type ATPase, CDF (Cation Diffusion Facilitator), HupE/UreJ and CHR (chromate ion transporter) family involved in copper, zinc, nickel as well as chromate resistance and homeostasis. Meanwhile, the putative CopA/CueO system is expected to mediate copper resistance in Sinorhizobium meliloti CCNWSX0020 while ZntA transporter, assisted with putative CzcD, determines zinc tolerance in Agrobacterium tumefaciens CCNWGS0286. The greenhouse experiment provides the consistent evidence of the plant growth promoting effects of these microbes on their hosts by nitrogen fixation and/or indoleacetic acid (IAA) secretion, indicating a potential in-site phytoremediation usage in the mining tailing regions of China. Copyright © 2014. Published by Elsevier B.V.

Bedrock geologic map of the Yucca Mountain area, Nye County, Nevada

International Nuclear Information System (INIS)

Day, W.C.; Potter, C.J.; Sweetkind, D.S.; Fridrich, C.J.; Dickerson, R.P.; San Juan, C.A.; Drake, R.M. II

1998-01-01

Yucca Mountain, Nye County, Nevada, has been identified as a potential site for underground storage of high-level radioactive nuclear waste. Detailed bedrock geologic maps form an integral part of the site characterization program by providing the fundamental framework for research into the geologic hazards and hydrologic behavior of the mountain. This bedrock geologic map provides the geologic framework and structural setting for the area in and adjacent to the site of the potential repository. The study area comprises the northern and central parts of Yucca Mountain, located on the southern flank of the Timber Mountain-Oasis Valley caldera complex, which was the source for many of the volcanic units in the area. The Timber Mountain-Oasis Valley caldera complex is part of the Miocene southwestern Nevada volcanic field, which is within the Walker Lane belt. This tectonic belt is a northwest-striking megastructure lying between the more active Inyo-Mono and Basin-and-Range subsections of the southwestern Great Basin

Bedrock geologic map of the Yucca Mountain area, Nye County, Nevada

Energy Technology Data Exchange (ETDEWEB)

Day, W.C.; Potter, C.J.; Sweetkind, D.S.; Fridrich, C.J. [Geological Survey, Denver, CO (US); Dickerson, R.P.; San Juan, C.A.; Drake, R.M. II [Pacific Western Technologies, Inc., Denver, CO (US)

1998-11-01

Yucca Mountain, Nye County, Nevada, has been identified as a potential site for underground storage of high-level radioactive nuclear waste. Detailed bedrock geologic maps form an integral part of the site characterization program by providing the fundamental framework for research into the geologic hazards and hydrologic behavior of the mountain. This bedrock geologic map provides the geologic framework and structural setting for the area in and adjacent to the site of the potential repository. The study area comprises the northern and central parts of Yucca Mountain, located on the southern flank of the Timber Mountain-Oasis Valley caldera complex, which was the source for many of the volcanic units in the area. The Timber Mountain-Oasis Valley caldera complex is part of the Miocene southwestern Nevada volcanic field, which is within the Walker Lane belt. This tectonic belt is a northwest-striking megastructure lying between the more active Inyo-Mono and Basin-and-Range subsections o f the southwestern Great Basin.

Fire history and climate characteristics during the last millennium of the Great Hinggan Mountains at the monsoon margin in northeastern China

Science.gov (United States)

Gao, Chuanyu; He, Jiabao; Zhang, Yan; Cong, Jinxin; Han, Dongxue; Wang, Guoping

2018-03-01

The northeastern region of China, at the limit of the summer monsoon, is characterized by the presence of mountains that influenced by the Asian summer monsoon on one side and the westerlies on the other; however, few studies have compared the environmental characteristics on the two sides of these mountains. In this study, two peatland cores from the western and eastern sides of the Great Hinggan Mountains were investigated to better understand the climatic and environmental conditions and the measurements of black carbon (BC) and δ13C-BC were used to reconstruct the fire history and environmental characteristics during the last millennium. Our results showed that the variations in the δ13C-BC values are more sensitive to climate changes than the BC fluxes, and the climate forcing mechanisms differed between the two sides of the mountains. Lower δ13C-BC values around 500 cal yr BP on the western side of the mountains indicated climate conditions were wetter than that on the eastern side, and were influenced by low sea surface temperatures in the North Atlantic Ocean. The region east of the mountains was mainly influenced by the strong Asian summer monsoon, and the decreasing of δ13C-BC values indicated climate conditions became wetter from 250 cal yr BP to the present and were wetter than that on the western side after 150 cal yr BP. Moreover, when one of these two forcing factors weakened and the other strengthened (e.g. from 400 to 150 cal yr BP), climate conditions in these two sides were similar.

A new vision of the intracontinental evolution of the eastern Kunlun Mountains, Northern Qinghai-Tibet plateau, China

International Nuclear Information System (INIS)

Yuan, W.-M.; Zhang, X.-T.; Dong, J.-Q.; Tang, Y.-H.; Yu, F.-S.; Wang, S.-C.

2003-01-01

Based on apatite fission track ages (FTA) of 41 samples collected from a south-north transect of the eastern Kunlun mountains, Qinghai-Tibet Plateau, China, this paper shows that (1) the FTA in different blocks increases with the distance from the South-Kunlun fault and Mid-Kunlun faults, respectively, indicating the control of the main faults on the tectonic evolution of this region; and (2) the thermal histories are characterized by slow cooling from ∼160 deg. C to ∼80 deg. C at ∼240 to ∼20 Ma, followed by rather rapid cooling to surface temperatures

Phylogeographical structure inferred from cpDNA sequence variation of Zygophyllum xanthoxylon across north-west China.

Science.gov (United States)

Shi, Xiao-Jun; Zhang, Ming-Li

2015-03-01

Zygophyllum xanthoxylon, a desert species, displaying a broad east-west continuous distribution pattern in arid Northwestern China, can be considered as a model species to investigate the biogeographical history of this region. We sequenced two chloroplast DNA spacers (psbK-psbI and rpl32-trnL) in 226 individuals from 31 populations to explore the phylogeographical structure. Median-joining network was constructed and analysis of AMOVA, SMOVA, neutrality tests and distribution analysis were used to examine genetic structure and potential range expansion. Using species distribution modeling, the geographical distribution of Z. xanthoxylon was modeled during the present and at the Last Glacial Maximum (LGM). Among 26 haplotypes, one was widely distributed, but most was restricted to either the eastern or western region. The populations with the highest levels of haplotype diversity were found in the Tianshan Mountains and its surroundings in the west, and the Helan Mountains and Alxa Plateau in the east. AMOVA and SAMOVA showed that over all populations, the species lacks phylogeographical structure, which is speculated to be the result of its specific biology. Neutrality tests and mismatch distribution analysis support past range expansions of the species. Comparing the current distribution to those cold and dry conditions in LGM, Z. xanthoxylon had a shrunken and more fragmented range during LGM. Based on the evidences from phylogeographical patterns, distribution of genetic variability, and paleodistribution modeling, Z. xanthoxylon is speculated most likely to have originated from the east and migrated westward via the Hexi Corridor.

Assessing and adapting to climate change in the Blue Mountains, Oregon (USA: Overview, biogeography, and climate

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Jessica E. Halofsky

2018-04-01

Full Text Available The Blue Mountains Adaptation Partnership (BMAP was established to increase climate change awareness, assess vulnerability to climate change, and develop science-based adaptation strategies for national forest lands in the Blue Mountains region of northeast Oregon and southeast Washington (USA. The BMAP process included (1 development of a science-management partnership, (2 a vulnerability assessment of the effects of climate change on natural resources and infrastructure, (3 development of adaptation options that will help reduce negative effects of climate change and assist the transition of biological systems and management to a changing climate, and (4 ongoing dialogue and activities related to climate change in the Blue Mountains region. This special issue of Climate Services describes social context and climate change vulnerability assessments for water use and infrastructure, vegetation, and riparian ecosystems of the Blue Mountains region, as well as adaptation options for natural resource management. This manuscript introduces the special issue, describing the management, biogeographic, and climatic context for the Blue Mountains region; the climate change vulnerability assessment and adaptation process used in BMAP; and the potential applications of the information described in the special issue. Although the institutional focus of information in the special issue is U.S. Forest Service lands (Malheur, Umatilla, and Wallowa-Whitman National Forests, the broader social context and adaptation options should be applicable to other lands throughout this region and the Pacific Northwest. Keywords: Climate change adaptation, Pacific Northwest, Resource management, Vulnerability assessment, Blue Mountains

Behavior of Agricultural water users induced hydro-climatic cycle change in Heihe River Basin, in the northwest of china

Science.gov (United States)

Wu, F.; Deng, X.; Cai, X.; Zhang, X.; Zhang, Q.

2017-12-01

Water allocation unbalance is the most important driving force of ecological degradation in the Heihe River Basin, where it seems the lifeblood of environment and human society. Water commute complex and frequent in soil, atmosphere, surface and ground face. The balance analysis of Water's transformation based on the WRF (Weather Research Forecasting) and SWAT (Soil and Water Assessment Tool) simulations, puts forward the application of land governance in arid and semi-arid region. In this study, we designed an irrigation scheme using local field experiences and incorporated the irrigation scheme into WRF/Noah-MP model. Then, to test the effects of irrigation scheme on performance of WRF/Noah-MP model, we carried out two simulations with the Heihe watershed, Northwest China, as a case study area. Firstly, the irrigation simulation is meanly about 860 mm across all of 671 cropland grid cells within the Heihe watershed and gradually increases from about 500 mm nearby the foot of Qilian Mountain to the maximum about 1500 mm in the middle and lower reach of Heihe River. Both of regional mean value and spatial heterogeneity are close to ground measurements. Secondly, the irrigation simulation dramatically reduced the mean bias of specified humidity to -0.47 g kg-1 (accounting for 6.0% of observation) and RMSE of temperature to 0.47 °C, respectively, since the irrigation enhanced the surface latent heat and weakened sensible heat to atmosphere. Thirdly, Across the 8 agricultural sites, the correlation coefficient and RMSE increased from 0.75 to 0.80. Finally, we found the surface runoff will increase by 0.46% with SWAT model at irrigation months. Therefore, the irrigation may led to expansion of cultivated land through transformation from groundwater to surface water at some degree. Water authorities should strengthen the tough water management measures to implement measures of total quantity control and raise the efficiency of water resources.

A review of research on ecosystem of arid area using RS-GIS in China

Science.gov (United States)

Han, Hongling

2007-06-01

Arid area is classical mountain-oasis-desert ecosystem in North-west China. As the ecosystem has its nature geography character obviously, it has superior to research with remote-sensing and geography information system. The study on arid ecosystem in RS-GIS' way is focused on that the landscape spatial pattern of complex MODS ecosystem, the dynamic development of Land use/land cover, the security of ecological environment of eco-tone and so on. At the same time, the research on the single system is more and more, which has provided more ways and deeper fields of arid area using RS-GIS. Through the use of RS-GIS, desertification, oasis' development, urbanization etc. can be known, which would provide precaution for human-being and suitable ways to adjust the problems.

Field occurrences and petrology of eclogites from the Dabie Mountains, Anhui, central China

Science.gov (United States)

Wang, X.; Jing, Y.; Liou, J. G.; Pan, G.; Liang, W.; Xia, M.; Maruyama, S.

1990-11-01

Four distinct types of eclogites are recognized according to their field occurrences and mineral parageneses in a gneiss terrane of the Dabie Mountains, a collision zone between the Sino-Korean and Yangtze cratons in central China. Some eclogites contain coesite and its quartz pseudomorphs enclosed in garnet and omphacite. Type I eclogites occur as layers in serpentinites and contain garnet, clinopyroxene, orthopyroxene, phengite, rutile, and coesite pseudomorph. Type II eclogites occur as lenticular bodies inside serpentinites and contain garnet, clinopyroxene, quartz, rutile, and edenitic hornblende. Type III eclogites occur as blocks of 2 cm to 20 m in size in a matrix of hornblende gneiss and biotite gneiss, and Type IV eclogites occur as thin layers interbedded with amphibolites. P- T estimates for these different eclogites indicate that they were formed under different physical conditions. All the eclogites were affected by later regional metamorphism for which the P- T conditions are estimated. This paper provides an introduction to the abundant eclogites from central China which have not been reported previously in Western literature. Specifically, the mode of field occurrence, petrography, mineral chemistry and formation conditions of the four types of eclogites are described. The paper is thus designed to establish a petrological framework for future detailed studies of the eclogites and their country rocks in an ancient zone of collision.

The mountain Cer: Potentials for tourism development

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Grčić Mirko D.

2003-01-01

Full Text Available In northwest of Serbia in the meridians directions an elongated mountain range of Cer with Iverak and Vlašić stretches itself. On the north it goes down to Mačva and Posavina, on the west to Podrinje, on the east to the valley of Kolubara, on the south to the basins and valleys of Jadar and upper Kolubara, which separate it from the mountains of Valjevo and Podrinje area. Cer mountain offers extremely good condition for development of eco-tourism. The variety of relief with gorgeous see-sites, natural rarities, convenient bio-climatic conditions, significant water resources, forest complexes, medieval fortresses, cultural-historic monuments, richness of flora and fauna, preserved rural environment, traditions and customs of local population, were all neglected as strategic factors in the development of tourism. This mountain’s potentials are quite satisfactory for the needs of eco-tourism, similar to the National Park of Fruška Gora, but it has lacked an adequate ecotourist strategy so far. This study aims to pointing to the potential and possibilities of ecotourist valorization of this mountain.

Influence of different topographic correction strategies on mountain vegetation classification accuracy in the Lancang Watershed, China

Science.gov (United States)

Zhang, Zhiming; de Wulf, Robert R.; van Coillie, Frieke M. B.; Verbeke, Lieven P. C.; de Clercq, Eva M.; Ou, Xiaokun

2011-01-01

Mapping of vegetation using remote sensing in mountainous areas is considerably hampered by topographic effects on the spectral response pattern. A variety of topographic normalization techniques have been proposed to correct these illumination effects due to topography. The purpose of this study was to compare six different topographic normalization methods (Cosine correction, Minnaert correction, C-correction, Sun-canopy-sensor correction, two-stage topographic normalization, and slope matching technique) for their effectiveness in enhancing vegetation classification in mountainous environments. Since most of the vegetation classes in the rugged terrain of the Lancang Watershed (China) did not feature a normal distribution, artificial neural networks (ANNs) were employed as a classifier. Comparing the ANN classifications, none of the topographic correction methods could significantly improve ETM+ image classification overall accuracy. Nevertheless, at the class level, the accuracy of pine forest could be increased by using topographically corrected images. On the contrary, oak forest and mixed forest accuracies were significantly decreased by using corrected images. The results also showed that none of the topographic normalization strategies was satisfactorily able to correct for the topographic effects in severely shadowed areas.

A deep water turbidity origin for the Altuda Formation (Capitanian, Permian), Northwest Glass Mountains, Texas

Science.gov (United States)

Haneef, Mohammad; Rohr, D.M.; Wardlaw, B.R.

2000-01-01

The Altuda Formation (Capitanian) in the northwestern Glass Mountains is comprised of thin, even bedded limestones, dolostones, mixed clastic-carbonates, and silt/sandstones interbedded with basin-ward dipping wedge-shaped clinoforms of the Captian Limestone. The formation is characterized by graded bedding, planar laminations, flame structures, contorted/convolute bedding, horizontal branching burrows, and shelf-derived normal marine fauna. A detailed study of the Altuda Formation north of Old Blue Mountain, Glass Mountains, reveals that the formation in this area was deposited by turbidity currents in slope to basinal settings.

Validation and Spatiotemporal Distribution of GEOS-5-Based Planetary Boundary Layer Height and Relative Humidity in China

Science.gov (United States)

Si, Yidan; Li, Shenshen; Chen, Liangfu; Yu, Chao; Wang, Zifeng; Wang, Yang; Wang, Hongmei

2018-04-01

Few studies have specifically focused on the validation and spatiotemporal distribution of planetary boundary layer height (PBLH) and relative humidity (RH) data in China. In this analysis, continuous PBLH and surface-level RH data simulated from GEOS-5 between 2004 and 2012, were validated against ground-based observations. Overall, the simulated RH was consistent with the statistical data from meteorological stations, with a correlation coefficient of 0.78 and a slope of 0.9. However, the simulated PBLH was underestimated compared to LIDAR data by a factor of approximately two, which was primarily because of poor simulation in late summer and early autumn. We further examined the spatiotemporal distribution characteristics of two factors in four regions—North China, South China, Northwest China, and the Tibetan Plateau. The results showed that the annual PBLH trends in all regions were fairly moderate but sensitive to solar radiation and precipitation, which explains why the PBLH values were ranked in order from largest to smallest as follows: Tibetan Plateau, Northwest China, North China, and South China. Strong seasonal variation of the PBLH exhibited high values in summer and low values in winter, which was also consistent with the turbulent vertical exchange. Not surprisingly, the highest RH in South China and the lowest RH in desert areas of Northwest China (less than 30%). Seasonally, South China exhibited little variation, whereas Northwest China exhibited its highest humidity in winter and lowest humidity in spring, the maximum values in the other regions were obtained from July to September.

Research on Fluid Viscous Damper Parameters of Cable-Stayed Bridge in Northwest China

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Xiongjun He

2017-01-01

Full Text Available To optimize the aseismic performance of nonlinear fluid viscous dampers (FVD of cable-stayed bridge in the highly seismic zone, Xigu Yellow River Bridge in northwest China is taken as an example. Nonlinear time-history analysis method is used to research on the relation among the internal forces, displacements, and damping parameters of the 650 tonnage FVD. The method of getting the minimum of binary functions is used to obtain the optimal parameters of FVD. Also, the 1 : 1 full-scale FVD model is made and used in the constitutive relation test. Then the test result of the damping parameters can be got by normal equation method. The optimized method to obtain the damping parameters is further verified. The results indicate that seismic response in key positions of the cable-stayed bridge can be reduced by installing longitudinal nonlinear FVD between the towers and girders if choosing reasonable damping parameters C and ξ. The optimal damping parameters can be calculated accurately by the proposed method of optimizing damping parameters of nonlinear FVD, and the constitutive relation test verifies the correctness of the optimization analysis method. Conclusions concerned can be applied to the design of nonlinear FVD for cable-stayed bridges.

Experimental Study on Productivity Performance of Household Combined Thermal Power and Biogas System in Northwest China

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Jian Kang

2018-01-01

Full Text Available Ample quantities of solar and local biomass energy are available in the rural regions of northwest China to satisfy the energy needs of farmers. In this work, low-temperature solar thermal collectors, photovoltaic solar power generators, and solar-powered thermostatic biogas digesters were combined to create a heat, electricity, and biogas cogeneration system and were experimentally studied through two buildings in a farming village in northwestern China. The results indicated that the floor heater had the best heating effect. And the fraction of the energy produced by the solar elements of the system was 60.3%. The photovoltaic power-generation system achieved photovoltaic (PV conversion efficiencies of 8.3% and 8.1% during the first and second season, respectively. The intrinsic power consumption of the system was 143.4 kW·h, and 115.7 kW·h of electrical power was generated by the system in each season. The average volume of biogas produced daily was approximately 1.0 m3. Even though the ambient temperature reached −25°C, the temperature of the biogas digester was maintained at 27°C ± 2 for thermostatic fermentation. After optimization, the energy-saving rate improved from 66.2% to 85.5%. The installation reduced CO2 emissions by approximately 27.03 t, and the static payback period was 3.1 yr. Therefore, the system is highly economical, energy efficient, and beneficial for the environment.

Experimental Study on Productivity Performance of Household Combined Thermal Power and Biogas System in Northwest China

Science.gov (United States)

Zhen, Xiaofei; Osman, Yassir Idris Abdalla; Feng, Rong; Si, Zetian

2018-01-01

Ample quantities of solar and local biomass energy are available in the rural regions of northwest China to satisfy the energy needs of farmers. In this work, low-temperature solar thermal collectors, photovoltaic solar power generators, and solar-powered thermostatic biogas digesters were combined to create a heat, electricity, and biogas cogeneration system and were experimentally studied through two buildings in a farming village in northwestern China. The results indicated that the floor heater had the best heating effect. And the fraction of the energy produced by the solar elements of the system was 60.3%. The photovoltaic power-generation system achieved photovoltaic (PV) conversion efficiencies of 8.3% and 8.1% during the first and second season, respectively. The intrinsic power consumption of the system was 143.4 kW·h, and 115.7 kW·h of electrical power was generated by the system in each season. The average volume of biogas produced daily was approximately 1.0 m3. Even though the ambient temperature reached −25°C, the temperature of the biogas digester was maintained at 27°C ± 2 for thermostatic fermentation. After optimization, the energy-saving rate improved from 66.2% to 85.5%. The installation reduced CO2 emissions by approximately 27.03 t, and the static payback period was 3.1 yr. Therefore, the system is highly economical, energy efficient, and beneficial for the environment. PMID:29862289

Extensional tectonics and sedimentary response of the Early–Middle Cambrian passive continental margin, Tarim Basin, Northwest China

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Zhiqian Gao

2012-09-01

Full Text Available The fact that several half-grabens and normal faults developed in the Lower–Middle Cambrian of Tazhong (central Tarim Basin and Bachu areas in Tarim Basin, northwest China, indicates that Tarim Basin was under extensional tectonic setting at this time. The half-grabens occur within a linear zone and the normal faults are arranged in en echelon patterns with gradually increasing displacement eastward. Extensional tectonics resulted in the formation of a passive continental margin in the southwest and a cratonic margin depression in the east, and most importantly, influenced the development of a three-pronged rift in the northeast margin of the Tarim Basin. The fault system controlled the development of platform – slope – bathyal facies sedimentation of mainly limestone-dolomite-gypsum rock-saline rock-red beds in the half-grabens. The NW-SE trending half-grabens reflect the distribution of buried basement faults.

Evaluation of the tourism climate in the Hexi Corridor of northwest China's Gansu Province during 1980-2012

Science.gov (United States)

Zhang, Fuxian; Zhang, Mingjun; Wang, Shengjie; Qiang, Fang; Che, Yanjun; Wang, Jie

2017-08-01

As a pivotal section of the Silk Road in northwest China, the Hexi Corridor is a popular tourist destination. In this study, the tourism climate conditions in this region were discussed using the Physiologically Equivalent Temperature (PET) and the Climate-Tourism/Transfer-information-Scheme (CTIS) from 1980 to 2012. Overall, cold or cool stress was prevalent in the area, and the optimal travel period was from May to September. With global warming, the annual numbers of cumulative days with relatively cold conditions decreased, and the annual numbers of cumulative days with comfortable and relatively hot conditions increased. Two typical stations, Wushaoling and Dunhuang, were compared and analysed for their tourism climate information according to the frequency of PET and CTIS conditions, respectively. In addition, regional variations in the tourism climate conditions based on geographic information systems (GIS) were investigated during the optimal travel period.

Multi-element characterization and source identification of trace metal in road dust from an industrial city in semi-humid area of Northwest China

International Nuclear Information System (INIS)

Mengmeng Zhang; Xinwei Lu; Hao Chen; Panpan Gao; Yi Fu

2015-01-01

Concentrations and sources of multi-elements in road dusts from an industrial city of northwest China were determined. Dust samples have elevated concentrations of Co, Cr, Cu, Pb, Zn, Sr and Ba. The dusts were mainly moderate enrichment by Co and Pb, minimal enrichment to moderate enrichment by Sr and Zn, and deficiency to minimal enrichment by other trace metals. Mn, V, Y, La, Hf, Th and U originated from soil. Cu, Pb, Cr, Ba and Sr mainly derived from traffic. Co, Zr, Ni, Ga, As and Zn have mixed sources of nature, industry and traffic. (author)

Main types and metallogenetic characteristics of sandstone-type uranium deposits in central asian mobile belt and its neighbouring area, and the study on prospecting direction of northwest China

International Nuclear Information System (INIS)

Fu Chengming

2007-01-01

Based on the study of geotectonic setting, formation evolution model and metallogenic characteristics of uranium productive basins, important sandstone-type uranium deposits in Central Asian mobile belt and neighbouring area are divided into five types. The statial distribution pattern of different sandstone-type uranium deposits is analyzed in detail. Geotectonic setting and metallogenetic characteristics are discussed. Finally, the characteristics of basin geodynamics, prospecting type and ore-bearing stratigraphy in Northwest China have been proposed. (authors)

Trends in population blood pressure and prevalence, awareness, treatment, and control of hypertension among middle-aged and older adults in a rural area of Northwest China from 1982 to 2010.

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Yaling Zhao

Full Text Available OBJECTIVES: To assess trends in average blood pressure levels and prevalence, awareness, treatment, and control of hypertension among adults in a rural area of Northwest China, and to determine associated risk factors. METHODS: Four cross-sectional population-based surveys were conducted between 1982 and 2010 among randomly selected adults in rural areas of Hanzhong, in Northwest China. Data on blood pressure, body mass index, family history of hypertension, and socio-demographic and lifestyle characteristics were collected in similar way by trained investigators in four surveys. Data of 8575 participants aged 35-64 years was analyzed. Averages and proportions were adjusted for age and sex. RESULTS: Average blood pressure in the population has increased since 1982 from 76.9 mm Hg to 79.6 mm Hg in 2010 (diastolic and from 120.9 to 129.7 mm Hg (systolic. Prevalence of hypertension increased from 18.4% in 1982 to 30.5% in 2010, and awareness of hypertension increased from 16.8% to 38.4% in 2010. Treatment of hypertension increased from 1.0% in 1982 to 17.4% in 2010, and control of hypertension increased from 0.1% in 1982 to 3.5% in 2010. All these gradients were statistically significant (P<0.01 for trend. Population blood pressure and prevalence, awareness and treatment of hypertension were positively associated with increasing age, body mass index and having family history of hypertension. CONCLUSIONS: Average blood pressure levels and the prevalence, awareness, treatment and control of hypertension among adults in rural areas of Hanzhong have increased since 1982. However, awareness, treatment and control rates remain low. Public health programs and practical strategies are required to improve prevention and control of hypertension in rural Northwest China. In particular, attention should be given to the elderly and obese, and to those with a family history of hypertension, while raising awareness and treatment among younger adults.

Distribution and speciation of mercury in the peat bog of Xiaoxing'an Mountain, northeastern China

International Nuclear Information System (INIS)

Liu Ruhai; Wang Qichao; Lu Xianguo; Fang Fengman; Wang Yan

2003-01-01

Peat bogs in northeastern China contain high levels of mercury from atmospheric deposition. - Most reports on mercury (Hg) in boreal ecosystems are from the Nordic countries and North America. Comparatively little information is available on Hg in wetlands in China. We present here a study on Hg in the Tangwang River forested catchment of the Xiaoxing'an Mountain in the northeast of China. The average total Hg (THg) in peat profile ranged from 65.8 to 186.6 ng g -1 dry wt with the highest at the depth of 5-10 cm. THg in the peat surface was higher than the background in Heilongjiang province, the Florida Everglades, and Birkeness in Sweden. MethylHg (MeHg) concentration ranged from 0.16 to 1.86 ng g -1 dry wt, with the highest amount at 10-15 cm depth. MeHg content was 0.2-1.2% of THg. THg and MeHg all decreased with the depth. THg in upland layer of soil (0-20 cm) was comparable to the peat surface, but in deeper layers THg concentration in peat was much higher than that in the forested mineral soil. THg in the peat bog increased, but MeHg decreased after it was drained. THg content in plant was different; THg contents in moss (119 ng g -1 dry wt, n=12) were much higher than in the herbage, the arbor, and the shrubs. The peat bog has mainly been contaminated by Hg deposition from the atmosphere

Oasis Irrigation-Induced Hydro-Climatic Effects: A Case Study in the Hyper-Arid Region of Northwest China

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Nan Shan

2018-04-01

Full Text Available The response of potential evapotranspiration (ET0 to widespread irrigation is important to fully understand future regional climate changes and to infer adaptive management of agricultural water resources. The quantitative impact of irrigation on ET0 from 1960 to 2013 was evaluated using historical time series data of daily meteorological observations in the hyper-arid region of northwest China. The decreasing trends in ET0 were accelerated for meteorological stations in regions with oasis agriculture, especially in the summer and during the growing season. Irrigation led to a cooling effect on temperature, increased relative humidity and precipitation. All of these changes contributed to a larger decrease of ET0 trend. The findings of this study advance our insight into the effects of irrigation on dynamics in ET0 and meteorological factors. Further investigations to understand how ET0 responds to climate change and agricultural irrigation could provide guidance for determining effective measures of water resources for adapting to global change.

Radioactivity of soils from north-west side of Stara planina mountain

International Nuclear Information System (INIS)

Momcilovic, M.; Dragovic, S.

2007-01-01

In this paper specific activities of 238U, 232Th, 40K and 137Cs in soil samples collected from north-west side of Stara planina in 2006 are presented. Specific activities varied between 15.1 and 34.0 Bq/kg for 238U; 16.8 and 44.6 Bq/kg for 232Th; 358 and 765 Bq/kg for 40K and 3.89 and 58.7 Bq/kg for 137Cs. The wide ranges of specific activities are influenced by a variety of geological and ecological features of the investigated area. (author) [sr

Peat δ13Ccelluose-recorded wetting trend during the past 8000 years in the southern Altai Mountains, northern Xinjiang, NW China

Science.gov (United States)

Zhang, Dongliang; Feng, Zhaodong; Yang, Yunpeng; Lan, Bo; Ran, Min; Mu, Guijin

2018-05-01

There have been large discrepancies in the proposed mechanisms accounting for the wetting trend since ∼8.0 cal. kyr BP in the Altai Mountains and the surrounding areas. To validate or invalidate the widely reported wetting trend, we obtained a carbon isotope of cellulose (δ13Ccelluose)-recorded warm-season moisture history from a Narenxia (NRX) peat core in the southern Altai Mountains, northern Xinjiang, NW China. The δ13Ccelluose-recorded warm-season moisture reconstruction of the NRX peat core provides a strong support to the widely-reported proposition that the climate was generally dry before ∼8.0 cal. kyr BP and was changed to a wetting trend during the past ∼8000 years in the Altai Mountains and the surrounding areas. The wetting trend since ∼8.0 cal. kyr BP well resembles the increasing trend of the reconnaissance drought index (RDI) that was calculated on the basis of pollen-inferred temperature and precipitation data from the same core. The resemblance implies that the wetting trend during the past ∼8000 years resulted from the combined effect of temperature and precipitation.

Reflections on the exploration of paramilitary management in Northwest Regional Office

International Nuclear Information System (INIS)

Ye Herui; Wang Fuquan; Zhang Zijie

2013-01-01

This article aims to reflect on the exploration of paramilitary management in Northwest Regional Office of Nuclear and Radiation Safety Inspection, MEP, China under current situation, so as to the improve the working style construction of the regulatory team, strengthening consciousness on nuclear safety, and to promote the level of nuclear safety regulation. (authors)

The potential drivers in forming avian biodiversity hotspots in the East Himalaya Mountains of Southwest China.

Science.gov (United States)

Lei, Fumin; Qu, Yanhua; Song, Gang; Alström, Per; Fjeldså, Jon

2015-03-01

Little has been published to describe or interpret Asian biodiversity hotspots, including those in the East Himalayan Mountains of Southwest China (HMSC), thus making necessary a review of the current knowledge. The Pliocene and Pleistocene geological and glacial histories of the Asian continent differ from those of Europe and North America, suggesting different mechanisms of speciation and extinction, and, thus, different responses to climate changes during the Quaternary glaciations. This short review summarizes potential drivers in shaping and maintaining high species richness and endemism of birds in the HMSC. The geographical location at the junction of different biogeographical realms, the wide range of habitats and climates along the extensive elevational range, the complex topography and the distinct geological history of this region have probably contributed to the evolution of an exceptionally species-rich and endemic-rich, specialized montane avian fauna. The Mountain systems in the HMSC may have provided refugia where species survived during the glacial periods and barriers for preventing species dispersal after the glacial periods. More studies are required to further test this refugia hypothesis by comparing more cold-tolerent and warm-tolerent species. © 2014 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and Wiley Publishing Asia Pty Ltd.

Neotectonic inversion of the Hindu Kush-Pamir mountain region

Science.gov (United States)

Ruleman, C.A.

2011-01-01

The Hindu Kush-Pamir region of southern Asia is one of Earth's most rapidly deforming regions and it is poorly understood. This study develops a kinematic model based on active faulting in this part of the Trans-Himalayan orogenic belt. Previous studies have described north-verging thrust faults and some strike-slip faults, reflected in the northward-convex geomorphologic and structural grain of the Pamir Mountains. However, this structural analysis suggests that contemporary tectonics are changing the style of deformation from north-verging thrusts formed during the initial contraction of the Himalayan orogeny to south-verging thrusts and a series of northwest-trending, dextral strike-slip faults in the modern transpressional regime. These northwest-trending fault zones are linked to the major right-lateral Karakoram fault, located to the east, as synthetic, conjugate shears that form a right-stepping en echelon pattern. Northwest-trending lineaments with dextral displacements extend continuously westward across the Hindu Kush-Pamir region indicating a pattern of systematic shearing of multiple blocks to the northwest as the deformation effects from Indian plate collision expands to the north-northwest. Locally, east-northeast- and northwest-trending faults display sinistral and dextral displacement, respectively, yielding conjugate shear pairs developed in a northwest-southeast compressional stress field. Geodetic measurements and focal mechanisms from historical seismicity support these surficial, tectono-morphic observations. The conjugate shear pairs may be structurally linked subsidiary faults and co-seismically slip during single large magnitude (> M7) earthquakes that occur on major south-verging thrust faults. This kinematic model provides a potential context for prehistoric, historic, and future patterns of faulting and earthquakes.

Seroprevalence and risk factors of Chlamydia abortus infection in Tibetan sheep in Gansu province, northwest China.

Science.gov (United States)

Qin, Si-Yuan; Yin, Ming-Yang; Cong, Wei; Zhou, Dong-Hui; Zhang, Xiao-Xuan; Zhao, Quan; Zhu, Xing-Quan; Zhou, Ji-Zhang; Qian, Ai-Dong

2014-01-01

Chlamydia abortus, an important pathogen in a variety of animals, is associated with abortion in sheep. In the present study, 1732 blood samples, collected from Tibetan sheep between June 2013 and April 2014, were examined by the indirect hemagglutination (IHA) test, aiming to evaluate the seroprevalence and risk factors of C. abortus infection in Tibetan sheep. 323 of 1732 (18.65%) samples were seropositive for C. abortus antibodies at the cut-off of 1:16. A multivariate logistic regression analysis was used to evaluate the risk factors associated with seroprevalence, which could provide foundation to prevent and control C. abortus infection in Tibetan sheep. Gender of Tibetan sheep was left out of the final model because it is not significant in the logistic regression analysis (P > 0.05). Region, season, and age were considered as major risk factors associated with C. abortus infection in Tibetan sheep. Our study revealed a widespread and high prevalence of C. abortus infection in Tibetan sheep in Gansu province, northwest China, with higher exposure risk in different seasons and ages and distinct geographical distribution.

Evaluation of the pollution and human health risks posed by heavy metals in the atmospheric dust in Ebinur Basin in Northwest China.

Science.gov (United States)

Abuduwailil, Jilili; Zhaoyong, Zhang; Fengqing, Jiang

2015-09-01

Recently, a large amount of research assessing pollution levels and the related health risks posed by atmosphere dust has been undertaken worldwide. However, little work has been done in the oases of the arid regions of Northwest China. In this paper, we studied the pollution and health risks over a year of seven heavy metals in the atmospheric dust of Ebinur Basin, a typical oasis in Northwest China. The results showed the following: (1) The annual amount of atmospheric deposition in Ebinur Basin was 298.23 g m(-2) and the average monthly atmospheric deposition was 25.06 g m(-2). The average and maximum values of the seven heavy metals measured were all below the National Soil Environmental Quality Standards (2nd). (2) Heavy metals of Cu, Cr, and As in the atmospheric deposition mainly originated from the natural geological background, while Zn came from human activity. This study also showed that among the seven measured heavy metals, the ratios of the no-pollution status of Pb, Cd, and Hg were higher than those of others with moderate degrees of pollution also accounting for a certain ratio. (3) The carcinogenic risks from As, Cd, and Cr were all lower than the corresponding standard limit values, and these metals are considered not harmful to the health of the basin. However, there is a relatively high risk of exposure for children from hand-to-mouth intake, which is worthy of attention. This research showed that both human activity and natural factors, such as wind and altitude, influenced the heavy metal contents in the atmospheric dust of the study area. Furthermore, recent human activity in the study area had the most negative influence on the accumulation of the heavy metals and the corresponding health risks, especially for Hg, Pb, and Cd, which is worthy of attention.

Estimation of wind erosion from construction of a railway in arid Northwest China

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Benli Liu

2017-06-01

Full Text Available A state-of-the-art wind erosion simulation model, the Wind Erosion Prediction System and the United States Environmental Protection Agency's AP 42 emission factors formula, were combined together to evaluate wind-blown dust emissions from various construction units from a railway construction project in the dry Gobi land in Northwest China. The influence of the climatic factors: temperature, precipitation, wind speed and direction, soil condition, protective measures, and construction disturbance were taken into account. Driven by daily and sub-daily climate data and using specific detailed management files, the process-based WEPS model was able to express the beginning, active, and ending phases of construction, as well as the degree of disturbance for the entire scope of a construction project. The Lanzhou-Xinjiang High-speed Railway was selected as a representative study because of the diversities of different climates, soil, and working schedule conditions that could be analyzed. Wind erosion from different working units included the building of roadbeds, bridges, plants, temporary houses, earth spoil and barrow pit areas, and vehicle transportation were calculated. The total wind erosion emissions, 7406 t, for the first construction area of section LXS-15 with a 14.877 km length was obtained for quantitative analysis. The method used is applicable for evaluating wind erosion from other complex surface disturbance projects.

Application of UTCI in China from tourism perspective

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Ge, Quansheng; Kong, Qinqin; Xi, Jianchao; Zheng, Jingyun

2017-05-01

This study uses ERA-Interim reanalysis data and the Universal Thermal Climate Index (UTCI) to investigate the spatial pattern of thermal bioclimatic conditions in China. Our results show that the annual UTCI increases with decreasing latitude throughout most of China. Areas that experience "no thermal stress" are located southeast of the line formed by the Yanshan Mountains, Taihang Mountains, the southern edge of the Loess Plateau, and the eastern edge of the Qinghai-Tibet Plateau, with an area of 312.83e4 km2. During spring and autumn, the UTCI distribution is similar to the annual distribution. During summer, areas with "no thermal stress" cover the largest area (563.55e4 km2), including northern and southwestern China; in contrast, during winter, areas with "no thermal stress" only occur south of the Nanling Mountains. The annual number of days with "no thermal stress" increases from north to south in central and eastern China, exceeding 200 days in the Sichuan Basin, the southeastern coastal regions and the Yungui Plateau. The minimum and maximum values occur on the Qinghai-Tibet Plateau (≤10 days) and the southern Yungui Plateau (>280 days). Seasonal analysis indicates that there are over 70 days with "no thermal stress" in the Sichuan Basin, the Yungui Plateau and the middle and lower reaches of the Yangtze River during spring and autumn, while there are more than 80 days in northern and southwestern China during summer and over 80 days in areas south of the Nanling Mountains during winter. The results of this study can be helpful for optimization of the tourism industry and tourism destinations development in China.

Contingency table analysis of pebble lithology and roundness: A case study of Huangshui River, China and comparison to rivers in the Rocky Mountains, USA

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Miao, X.; Lindsey, D.A.; Lai, Z.; Liu, Xiuying

2010-01-01

Contingency table analysis of pebble lithology and roundness is an effective way to identify the source terrane of a drainage basin and to distinguish changes in basin size, piracy, tectonism, and other events. First, the analysis to terrace gravel deposited by the Huangshui River, northeastern Tibet Plateau, China, shows statistically contrasting pebble populations for the oldest terrace (T7, Dadongling, 1.2. Ma) and the youngest terraces (T0-T3, ?. 0.15. Ma). Two fluvial processes are considered to explain the contrast in correlation between lithology and roundness in T7 gravel versus T0-T3 gravel: 1) reworking of T7 gravel into T0-T3 gravel and 2) growth in the size of the river basin between T7 and T0-T3 times. We favor growth in basin size as the dominant process, from comparison of pebble counts and contingency tables. Second, comparison of results from Huangshui River of China to three piedmont streams of the Rocky Mountains, USA highlights major differences in source terrane and history. Like Rocky Mountain piedmont gravel from Colorado examples, the Huangshui gravels show a preference (observed versus expected frequency) for rounded granite. But unlike Rocky Mountain gravel, Huangshui gravel shows a preference for angular quartzite and for rounded sandstone. In conclusion, contrasting behavior of lithologies during transport, not always apparent in raw pebble counts, is readily analyzed using contingency tables to identify the provenance of individual lithologies, including recycled clasts. Results of the analysis may help unravel river history, including changes in basin size and lithology. ?? 2009.

Trace metal concentration in Great Tit (Parus major) and Greenfinch (Carduelis sinica) at the Western Mountains of Beijing, China

International Nuclear Information System (INIS)

Deng Haili; Zhang Zhengwang; Chang Chongyan; Wang Yong

2007-01-01

We examined the concentrations of 11 trace metals in tissues from 10 body parts of Great Tits and Greenfinches collected at Badachu Park in the Western Mountains of Beijing, China to assess the metal accumulation level, distribution among body parts, and species and gender related variations. The highest concentrations of Hg, Ni, Zn, and Mn were found in the feather; Pb and Co in the bone; Cd, Cr, and Se in the kidney, and Cu in the liver and heart. Metal concentrations had substantial interspecific variation with Great Tits showing higher levels of Hg, Cr, Ni, and Mn than Greenfinches in tissues of most body parts. Gender related variations were body part and species specific. Meta-analyses using data from this study and other studies suggested that metal concentrations of Great Tits at our study site were relatively low and below the toxic levels. - Trace metal concentrations of Great Tits and Greenfinches from Beijing, China, varied by body part, gender, and species, and were below toxic levels

Impacts of cwd on understory biodiversity in forest ecosystems in the qinling mountains, china

International Nuclear Information System (INIS)

Yuan, J.; Wei, X.; Shang, Z.; Cheng, F.; Hu, Z.; Zheng, X.; Zhang, S.

2015-01-01

The stocks and characteristics of coarse woody debris (CWD) are expected to reflect forest stand features. However, despite their importance, there have been no reports of CWD stocks and characteristics in the Qinling Mountains. We measured the CWD stocks in different CWD types, decay classes and diameter classes of the five forest types in the Qinling Mountains. The highest biomass of CWD was the Pinus tabulaeformis forest (12.57 t-hm /sup -2/), occupied 5.66 percentage in the biomass of this forest, the lowest occupied 1.03 percentage in Betula albo-sinensis forest (1.82 t-hm /sup -2/). Our results revealed that there was a strong correlation between CWD and forest biomass. When the CWD biomass were 9.9 t-hm /sup -2/ and 11.6 hm /sup -2/, the biomass of Pinus armandi forest and P. tabulaeformis forest reached maximum, respectively. CWD is particularly important for biodiversity, but the importance of CWD in the control of diversity in forest systems has not been fully appreciated and certainly has not been evaluated intensively within China, especially in Qinling forests. In our research, we used species richness (S), Shannon-Wiener index (H), Simpson index (D) and Pielou evenness index (J) to assess the diversity of plant community. According to our analysis, we found 1) the effect of CWD biomass on these a diversity index was dependent on tree, shrub and herb in the five forest types, 2) the impacts of CWD biomass on understory biodiversity were more obvious, 3) With the increase of CWD biomass, the species richness (S), Shannon-Wiener index (H) and Simpson index (D) of understory increased significantly. Our results suggested that there was a relatively lower CWD biomass in the Qinling Mountains, but it had significant effects on forest biomass and diversity of plant community. Reserving CWD was important for eco-forestry, but how many and how characteristic of CWD should be retained need further research. Development of CWD reasonable strategies was

Significance and effect of ecological rehabilitation project in inland river basins in northwest China.

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Wang, Yu; Feng, Qi; Chen, Lijuan; Yu, Tengfei

2013-07-01

The Ecological Water Transfer and Rehabilitation Project in the arid inland area of northwest China is an important measure in restoring a deteriorated ecosystem. However, the sustainability of the project is affected by many socio-economic factors. This article examines the attitudes of the local populace toward the project, its impact on the livelihood of the people, and the positive effects of water-efficient agricultural practices in Ejina County. Related data were collected through questionnaire surveys and group discussions. The results identified three critical issues that may influence the sustainability of the project in the study area. The first issue relates to the impact of the project on the livelihood of local herdsmen. The potential for the sustainability of the project is compromised because the livelihood of the herdsmen greatly depends on the compensation awarded by the project. The second issue is that the project did not raise the water resource utilization ratio, which may undermine its final purpose. Finally, the compensation provided by the project considers losses in agriculture, but neglects the externalities and public benefit of eco-water. Thus, appropriate compensation mechanisms should be established and adopted according to local economic, environmental, and social conditions. Some recommendations for improving the sustainability of the project are provided based on the results of this study.

Co-occurrence of arseniasis and fluorosis due to indoor combustion of high fluorine and arsenic content coal in a rural township in northwest China: epidemiological and toxicological aspects

Energy Technology Data Exchange (ETDEWEB)

Lin, Guo-fang; Shen, Jian-hua [Chinese Academy of Sciences, Shanghai Institutes for Biological Sciences, Institute of Plant Physiology and Ecology, Shanghai (China); Gong, Shi-you [County Center for Disease Control and Prevention of Ziyang, Ziyang, Shaanxi (China); Wei, Cheng [Township Clinics of Haoping, Ziyang, Shaanxi (China); Chen, Ji-gang [Municipal Center for Disease Prevention and Control of Shanghai, Shanghai (China); Golka, Klaus [Leibniz Research Centre for Working Environment and Human Factors (IfADo), Dortmund (Germany)

2012-06-15

A large number of fluorosis and arseniasis cases appeared in a mountainous area in northwest China. The residents relied on local inferior coal (''bone coal'') of high fluorine and arsenic content for domestic heating and cooking. For deep-inside information about this rare case of co-endemia of fluorosis and arseniasis in the population in this special exposure scenario, a field investigation in one of the hyperendemic townships was conducted. The resident population registered (n = 27,713) was enrolled in the investigation. All cases were diagnosed and assigned to three symptom severity groups, that is severe, medium, and mild according to Chinese National Standard Criteria GB 16396-96 and to the technical guideline WS/T208-01 or WS/T211-01 issued by the Chinese Ministry of Health. Gender difference was analyzed by standardized incidence ratio. Age trend and severity trend were tested by {chi}{sup 2} analysis. Fluorosis was diagnosed in 56.7% of the residents. Over 95% of the diagnosed arseniasis cases were simultaneously diagnosed with fluorosis symptoms. Combined fluorosis-arseniasis represented 11.9% of the total fluorosis cases and 6.7% of the local population. No gender-related differences in the prevalence of skeletal, dental, or dermal symptoms inside all severity groups were detected. Symptom severity increased with age. The high frequency of superposition of arseniasis with fluorosis might be due to the fact that the local resident population has been exposed to very high levels of fluorine and arsenic via the same exposure route. (orig.)

Development of rail access to the proposed repository site at Yucca Mountain

International Nuclear Information System (INIS)

Standish, P.N.; Seidler, P.E.; Andrews, W.B.; Shearin, G.

1991-01-01

In accordance with the Nuclear Waste Policy Amendment Act of 1987, Yucca Mountain was designated as the initial site to be investigated as a potential repository for the disposal of high-level radioactive waste. The Yucca Mountain site is an undeveloped area located on the southwestern edge of the Nevada Test Site (NTS), about 100 miles northwest of Las Vegas. The site currently lacks rail service or an existing right-of-way. If the Yucca Mountain site is found suitable for the repository, rail service is considered desirable by the Office of Civilian Radioactive Waste Management (OCRWM) program because of the potential of rail transportation to reduce (1) costs and (2) number of shipments, relative to highway transportation. Therefore, it is necessary to conduct a study to determine (1) that there are alignments for a potential rail line from existing mainline railroads to Yucca Mountain and (2) that these are consistent with present rail design standards and are acceptable relative to environmental and land access considerations

A long-term simulation of forest carbon fluxes over the Qilian Mountains

Science.gov (United States)

Yan, Min; Tian, Xin; Li, Zengyuan; Chen, Erxue; Li, Chunmei; Fan, Wenwu

2016-10-01

In this work, we integrated a remote-sensing-based (the MODIS MOD_17 Gross Primary Productivity (GPP) model (MOD_17)) and a process-based (the Biome-BioGeochemical Cycles (Biome-BGC) model) ecological model in order to estimate long-term (from 2000 to 2012) forest carbon fluxes over the Qilian Mountains in northwest China, a cold and arid forest ecosystem. Our goal was to obtain an accurate and quantitative simulation of spatial GPP patterns using the MOD_17 model and a temporal description of forest processes using the Biome-BGC model. The original MOD_17 model was first optimized using a biome-specific parameter, observed meteorological data, and reproduced fPAR at the eddy covariance site. The optimized MOD_17 model performed much better (R2 = 0.91, RMSE = 5.19 gC/m2/8d) than the original model (R2 = 0.47, RMSE = 20.27 gC/m2/8d). The Biome-BGC model was then calibrated using GPP for 30 representative forest plots selected from the optimized MOD_17 model. The calibrated Biome-BGC model was then driven in order to estimate forest GPP, net primary productivity (NPP), and net ecosystem exchange (NEE). GPP and NEE were validated against two-year (2010 and 2011) EC measurements (R2 = 0.79, RMSE = 1.15 gC/m2/d for GPP; and R2 = 0.69, RMSE = 1.087 gC/m2/d for NEE). NPP estimates from 2000 to 2012 were then compared to dendrochronological measurements (R2 = 0.73, RMSE = 24.46 gC/m2/yr). Our results indicated that integration of the two models can be used for estimating carbon fluxes with good accuracy and a high temporal and spatial resolution. Overall, NPP displayed a downward trend, with an average rate of 0.39 gC/m2/yr, from 2000 and 2012 over the Qilian Mountains. Simulated average annual NPP yielded higher values for the southeast as compared to the northwest. The most positive correlative climatic factor to average annual NPP was downward shortwave radiation. The vapor pressure deficit, and mean temperature and precipitation yielded negative correlations to average

The Evaluation of Land Use Status in Mountainous Counties of Southwest China Based on Comprehensive Evaluation Models: A Case Study of Baoxing County, Sichuan Province

Science.gov (United States)

Cao, Mengtian; Shen, Jundi; Chen, Zhehua

2018-06-01

In mountainous areas of Southwest China, the land resources are scarce, and the ecological environment is fragile, so it is particularly important to carry out the evaluation of land use status for the sustainability of land development. Taking Baoxing County in Sichuan Province, the typical mountainous county in Southwest China, as an instance, this study refers to the existing research frameworks to establish the evaluation system of land use status. Meanwhile, the comprehensive evaluation models are used to evaluate land use status. As indicated from the results, in Baoxing County, the comprehensive evaluation score of the overall status of land use, the evaluation score of the development degree of land, the evaluation score of the intensive management degree of land and the evaluation score of the comprehensive benefits of land were 83.5, 108.24, 72.25 and 80.77, respectively. Land use status is generally at the relatively rational use stage, and the main problems are the lack of land investment and the low mechanization level of agricultural production. It is suggested to increase the financial investment in land and enhance the intensive degree and comprehensive benefits of land in the future.

Misty Mountains and Mountain Movers: Using Art and Literature in Teaching About Old and New China.

Science.gov (United States)

Haimes, Barbara

These learning activities can be used to show secondary level students how contemporary art and literature reflect the main trends of thought and values of the People's Republic of China. Students learn about two of the most important philosophies in old China--Confucianism and Taoism. They also learn about new China (China since 1949). Students…

Regional difference of the start time of the recent warming in Eastern China: prompted by a 165-year temperature record deduced from tree rings in the Dabie Mountains

Science.gov (United States)

Cai, Qiufang; Liu, Yu; Duan, Bingchuang; Sun, Changfeng

2018-03-01

Tree-ring studies from tropical to subtropical regions are rarer than that from extratropical regions, which greatly limit our understanding of some critical climate change issues. Based on the tree-ring-width chronology of samples collected from the Dabie Mountains, we reconstructed the April-June mean temperature for this region with an explained variance of 46.8%. Five cold (1861-1869, 1889-1899, 1913-1920, 1936-1942 and 1952-1990) and three warm (1870-1888, 1922-1934 and 2000-2005) periods were identified in the reconstruction. The reconstruction not only agreed well with the instrumental records in and around the study area, but also showed good resemblance to previous temperature reconstructions from nearby regions, indicating its spatial and temporal representativeness of the temperature variation in the central part of eastern China. Although no secular warming trend was found, the warming trend since 1970 was unambiguous in the Dabie Mountains (0.064 °C/year). Further temperature comparison indicated that the start time of the recent warming in eastern China was regional different. It delayed gradually from north to south, starting at least around 1940 AD in the north part, around 1970 AD in the central part and around 1980s in the south part. This work enriches the high-resolution temperature reconstructions in eastern China. We expect that climate warming in the future would promote the radial growth of alpine Pinus taiwanensis in the subtropical areas of China, therefore promote the carbon capture and carbon storage in the Pinus taiwanensis forest. It also helps to clarify the regional characteristic of recent warming in eastern China.

Common and Privatized: Conditions for Wise Management of Matsutake Mushrooms in Northwest Yunnan Province, China

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Xuefei Yang

2009-12-01

Full Text Available Since Hardin's (1968 paper on the "Tragedy of the Commons," property rights of common-pool resources have been a central concern for natural resource management scholars. Matsutake, a common-pool resource, is an economically important mushroom in several locations around the world. Driven by growing international demand over the last few decades, matsutake management is a relatively new practice both for local communities and government agencies. In Northwest Yunnan, China, one of the most productive areas for matsutake globally, numerous local practices and systems have emerged in the last two to three decades. In this study, we investigate the differences between management systems in eight communities and the factors associated with them. The methods used for field research included key-informant interviews, household surveys, and questionnaires. Three main management patterns were identified through use of statistical clustering based on indicators such as physical environment, resource characteristics, tenure arrangements, regulations and implementation, harvesting behavior, income, and market regulation. It was found that private access - the principal characteristic of which is the exclusive use of resources - results in more income at lower labor cost per household than either of the other open-access management patterns. Even though under the context of ongoing Second Forest Tenure Reform in China - in which collective forest privatization is the key task - application of private-access regimes is limited because of site conditions including physical, institutional, and market environments. Common-access management systems have advantages in terms of managing conflict and balancing equity needs. No matter the type of access right, the key issue for wise matsutake management is institutional. Locally rooted innovative strategies should be encouraged, and institutional capacity building should be carried out to support innovations in

Current strain accumulation in the hinterland of the northwest Himalaya constrained by landscape analyses, basin-wide denudation rates, and low temperature thermochronology

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Morell, Kristin D.; Sandiford, Mike; Kohn, Barry; Codilean, Alexandru; Fülöp, Réka-H.; Ahmad, Talat

2017-11-01

Rupture associated with the 25 April 2015 Mw 7.8 Gorkha (Nepal) earthquake highlighted our incomplete understanding of the structural architecture and seismic cycle processes that lead to Himalayan mountain building in Central Nepal. In this paper we investigate the style and kinematics of active mountain building in the Himalayan hinterland of Northwest India, approximately 400 km to the west of the hypocenter of the Nepal earthquake, via a combination of landscape metrics and long- (Ma) and short-term (ka) erosion rate estimates (from low temperature thermochronometry and basin-wide denudation rate estimates from 10Be concentrations). We focus our analysis on the area straddling the PT2, the physiographic transition between the Lesser and High Himalaya that has yielded important insights into the nature of hinterland deformation across much of the Himalaya. Our results from Northwest India reveal a distinctive PT2 that separates a Lesser Himalaya region with moderate relief (∼1000 m) and relatively slow erosion (400 km distance between them, similar spatiotemporal patterns of erosion and deformation observed in Northwest India and Central Nepal suggest both regions experience similar styles of active strain accumulation and both are susceptible to large seismic events.

Validation of a Process-Based Agro-Ecosystem Model (Agro-IBIS for Maize in Xinjiang, Northwest China

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Tureniguli Amuti

2018-03-01

Full Text Available Agricultural oasis expansion and intensive management practices have occurred in arid and semiarid regions of China during the last few decades. Accordingly, regional carbon and water budgets have been profoundly impacted by agroecosystems in these regions. Therefore, study on the methods used to accurately estimate energy, water, and carbon exchanges is becoming increasingly important. Process-based models can represent the complex processes between land and atmosphere among agricultural ecosystems. However, before the models can be applied they must be validated under different environmental and climatic conditions. In this study, a process-based agricultural ecosystem model (Agro-IBIS was validated for maize crops using 3 years of soil and biometric measurements at Wulanwusu agrometeorological site (WAS located in the Shihezi oasis in Xinjiang, northwest China. The model satisfactorily represented leaf area index (LAI during the growing season, simulating its peak values within the magnitude of 0–10%. The total biomass carbon was overestimated by 15%, 8%, and 16% in 2004, 2005, and 2006, respectively. The model satisfactorily simulated the soil temperature (0–10 cm and volumetric water content (VWC (0–25 cm of farmland during the growing season. However, it overestimated soil temperature approximately by 4 °C and VWC by 15–30% during the winter, coinciding with the period of no vegetation cover in Xinjiang. Overall, the results indicate that the model could represent crop growth, and seems to be applicable in multiple sites in arid oases agroecosystems of Xinjiang. Future application of the model will impose more comprehensive validation using eddy covariance flux data, and consider including dynamics of crop residue and improving characterization of the final stage of leaf development.

Geologic map of the Paintbrush Canyon Area, Yucca Mountain, Nevada

International Nuclear Information System (INIS)

Dickerson, R.P.; Drake, R.M. II

1998-01-01

This geologic map is produced to support site characterization studies of Yucca Mountain, Nevada, site of a potential nuclear waste storage facility. The area encompassed by this map lies between Yucca Wash and Fortymile Canyon, northeast of Yucca Mountain. It is on the southern flank of the Timber Mountain caldera complex within the southwest Nevada volcanic field. Miocene tuffs and lavas of the Calico Hills Formation, the Paintbrush Group, and the Timber Mountain Group crop out in the area of this map. The source vents of the tuff cones and lava domes commonly are located beneath the thickest deposits of pyroclastic ejecta and lava flows. The rocks within the mapped area have been deformed by north- and northwest-striking, dominantly west-dipping normal faults and a few east-dipping normal faults. Faults commonly are characterized by well developed fault scarps, thick breccia zones, and hanging-wall grabens. Latest movement as preserved by slickensides on west-dipping fault scarps is oblique down towards the southwest. Two of these faults, the Paintbrush Canyon fault and the Bow Ridge fault, are major block-bounding faults here and to the south at Yucca Mountain. Offset of stratigraphic units across faults indicates that faulting occurred throughout the time these volcanic units were deposited

Geologic map of the Paintbrush Canyon Area, Yucca Mountain, Nevada

Energy Technology Data Exchange (ETDEWEB)

Dickerson, R.P. [Geological Survey, Denver, CO (United States); Drake, R.M. II [Pacific Western Technologies, Ltd., Lakewood, CO (United States)

1998-11-01

This geologic map is produced to support site characterization studies of Yucca Mountain, Nevada, site of a potential nuclear waste storage facility. The area encompassed by this map lies between Yucca Wash and Fortymile Canyon, northeast of Yucca Mountain. It is on the southern flank of the Timber Mountain caldera complex within the southwest Nevada volcanic field. Miocene tuffs and lavas of the Calico Hills Formation, the Paintbrush Group, and the Timber Mountain Group crop out in the area of this map. The source vents of the tuff cones and lava domes commonly are located beneath the thickest deposits of pyroclastic ejecta and lava flows. The rocks within the mapped area have been deformed by north- and northwest-striking, dominantly west-dipping normal faults and a few east-dipping normal faults. Faults commonly are characterized by well developed fault scarps, thick breccia zones, and hanging-wall grabens. Latest movement as preserved by slickensides on west-dipping fault scarps is oblique down towards the southwest. Two of these faults, the Paintbrush Canyon fault and the Bow Ridge fault, are major block-bounding faults here and to the south at Yucca Mountain. Offset of stratigraphic units across faults indicates that faulting occurred throughout the time these volcanic units were deposited.

Runoff Effect Evaluation of LID through SWMM in Typical Mountainous, Low-Lying Urban Areas: A Case Study in China

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Qinghua Luan

2017-06-01

Full Text Available Urban flooding occurs frequently in many regions of China. To reduce the losses caused by urban flooding, sponge city (SPC and low-impact development (LID have been carried out in many Chinese cities. However, urban flooding is influenced by various factors, such as climate, land cover characteristics and nearby river networks, so it is necessary to evaluate the effectiveness of LID measures. In this study, the Storm Water Management Model (SWMM was adopted to simulate historical urban storm processes in the mountainous Fragrance Hills region of Beijing, China. Subsequently, numerical simulations were performed to evaluate how various LID measures (concave greenbelt, permeable pavement, bio-retention, vegetative swales, and comprehensive measures influenced urban runoff reduction. The results showed that the LID measures are effective in controlling the surface runoff of the storm events with return periods shorter than five years, in particular, for one-year events. Furthermore, the effectiveness on traffic congestion mitigation of several LID measures (concave greenbelt, vegetative swales, and comprehensive measures was evaluated. However, the effective return periods of storm events are shorter than two years if the effectiveness on traffic congestion relief is considered. In all evaluated aspects, comprehensive measures and concave greenbelts are the most effective, and vegetative swale is the least effective. This indicated that LID measures are less effective for removing ponding from most storm events in a mountainous, low-lying and backward pipeline infrastructure region with pressures from interval flooding and urban waterlogging. The engineering measures including water conservancy projects and pipeline infrastructure construction combined with the non-engineering measures were suggested to effectively control severe urban storms.

[Climate-growth relationships of Picea koraiensis and causes of its recent decline in Xiaoxing' an Mountains, China].

Science.gov (United States)

Yao, Qi-chao; Wang, Xiao-chun; Xiao, Xing-wei

2015-07-01

Two tree-ring width chronologies of Picea koraiensis at two altitudes in Fenglin National Nature Reserve of Xiaoxing'an Mountains, China were developed by using dendrochronological methods. To identify main limiting factors of P. koraiensis radial growth at the two altitudes, the relationships between the chronologies and local temperature, precipitation, Palmer drought severity index (PDSI), and large-scale climatic factors were investigated. Meanwhile, the reasons of P. koraiensis growth decline in recent years were also explored. Results showed that radial growth of P. koraiensis in Xiaoxing'an Mountains was mainly limited by temperatures, especially by the minimum temperature in growing season, while the limiting effect of precipitation was relatively weak. Climate responses of P. koraiensis growth at the different altitudes showed significant differences. Radial growths of P. koraiensis at the low altitude were positively correlated with precipitation in the current growth season (June-September) and whole year, and negatively correlated with soil temperatures at different depths, especially at 80 cm depth in growing season. Meanwhile, it was signi-ficantly positively correlated with PDSI in growing season. However, the relationships between radial growth of P. koraiensis at the high altitude and precipitation, air and soil temperatures, and PDSI were not significant as that at the low altitude. Growth decline of P. koraiensis in Xiaoxing'an Mountains could be related to the phase changes in Atlantic multidecadal oscillation (AMO) and Pacific decadal oscillation (PDO) and the significant global warming since 1980. The coupling effects of the above changes might result in increased soil evaporation and exacerbated warming and drying phenomena, consequently causing the growth decline of P. koraiensis at the low altitude.

Extreme ground motions and Yucca Mountain

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Hanks, Thomas C.; Abrahamson, Norman A.; Baker, Jack W.; Boore, David M.; Board, Mark; Brune, James N.; Cornell, C. Allin; Whitney, John W.

2013-01-01

Yucca Mountain is the designated site of the underground repository for the United States' high-level radioactive waste (HLW), consisting of commercial and military spent nuclear fuel, HLW derived from reprocessing of uranium and plutonium, surplus plutonium, and other nuclear-weapons materials. Yucca Mountain straddles the western boundary of the Nevada Test Site, where the United States has tested nuclear devices since the 1950s, and is situated in an arid, remote, and thinly populated region of Nevada, ~100 miles northwest of Las Vegas. Yucca Mountain was originally considered as a potential underground repository of HLW because of its thick units of unsaturated rocks, with the repository horizon being not only ~300 m above the water table but also ~300 m below the Yucca Mountain crest. The fundamental rationale for a geologic (underground) repository for HLW is to securely isolate these materials from the environment and its inhabitants to the greatest extent possible and for very long periods of time. Given the present climate conditions and what is known about the current hydrologic system and conditions around and in the mountain itself, one would anticipate that the rates of infiltration, corrosion, and transport would be very low—except for the possibility that repository integrity might be compromised by low-probability disruptive events, which include earthquakes, strong ground motion, and (or) a repository-piercing volcanic intrusion/eruption. Extreme ground motions (ExGM), as we use the phrase in this report, refer to the extremely large amplitudes of earthquake ground motion that arise at extremely low probabilities of exceedance (hazard). They first came to our attention when the 1998 probabilistic seismic hazard analysis for Yucca Mountain was extended to a hazard level of 10-8/yr (a 10-4/yr probability for a 104-year repository “lifetime”). The primary purpose of this report is to summarize the principal results of the ExGM research program

Hydrologic comparison between a lowland catchment (Kielstau, Germany and a mountainous catchment (XitaoXi, China using KIDS model in PCRaster

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N. Fohrer

2009-08-01

Full Text Available The KIDS model (Kielstau Discharge Simulation model is a simple rainfall-runoff model developed originally for the Kielstau catchment. To extend its range of application we applied it to a completely different catchment, the XitaoXi catchment in China. Kielstau is a small (51 km² lowland basin in Northern Germany, with large proportion of wetland area. And XitaoXi is a mesoscale (2271 km² mountainous basin in the south of China. Both catchments differ greatly in size, topography, landuse, soil properties, and weather conditions. We compared two catchments in these features and stress on the analysis how the specific catchment characteristics could guide the adaptation of KIDS model and the parameter estimation for streamflow simulation. The Nash and Sutcliffe coefficient was 0.73 for Kielstau and 0.65 for XitaoXi. The results suggest that the application of KIDS model may require adjustments according to the specific physical background of the study basin.

3D Tomographic SAR Imaging in Densely Vegetated Mountainous Rural Areas in China and Sweden

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Feng, L.; Muller, J. P., , Prof

2017-12-01

3D SAR Tomography (TomoSAR) and 4D SAR Differential Tomography (Diff-TomoSAR) exploit multi-baseline SAR data stacks to create an important new innovation of SAR Interferometry, to unscramble complex scenes with multiple scatterers mapped into the same SAR cell. In addition to this 3-D shape reconstruction and deformation solution in complex urban/infrastructure areas, and recent cryospheric ice investigations, emerging tomographic remote sensing applications include forest applications, e.g. tree height and biomass estimation, sub-canopy topographic mapping, and even search, rescue and surveillance. However, these scenes are characterized by temporal decorrelation of scatterers, orbital, tropospheric and ionospheric phase distortion and an open issue regarding possible height blurring and accuracy losses for TomoSAR applications particularly in densely vegetated mountainous rural areas. Thus, it is important to develop solutions for temporal decorrelation, orbital, tropospheric and ionospheric phase distortion.We report here on 3D imaging (especially in vertical layers) over densely vegetated mountainous rural areas using 3-D SAR imaging (SAR tomography) derived from data stacks of X-band COSMO-SkyMed Spotlight and L band ALOS-1 PALSAR data stacks over Dujiangyan Dam, Sichuan, China and L and P band airborne SAR data (BioSAR 2008 - ESA) in the Krycklan river catchment, Northern Sweden. The new TanDEM-X 12m DEM is used to assist co - registration of all the data stacks over China first. Then, atmospheric correction is being assessed using weather model data such as ERA-I, MERRA, MERRA-2, WRF; linear phase-topography correction and MODIS spectrometer correction will be compared and ionospheric correction methods are discussed to remove tropospheric and ionospheric delay. Then the new TomoSAR method with the TanDEM-X 12m DEM is described to obtain the number of scatterers inside each pixel, the scattering amplitude and phase of each scatterer and finally extract

An Integrative Approach to Understand the Climatic-Hydrological Process: A Case Study of Yarkand River, Northwest China

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Jianhua Xu

2013-01-01

Full Text Available Taking the Yarkand River as an example, this paper conducted an integrative approach combining the Durbin-Watson statistic test (DWST, multiple linear regression (MLR, wavelet analysis (WA, coefficient of determination (CD, and Akaike information criterion (AIC to analyze the climatic-hydrological process of inland river, Northwest China from a multitime scale perspective. The main findings are as follows. (1 The hydrologic and climatic variables, that is, annual runoff (AR, annual average temperature, (AAT and annual precipitation (AP, are stochastic and, no significant autocorrelation. (2 The variation patterns of runoff, temperature, and precipitation were scale dependent in time. AR, AAT, and AP basically present linear trends at 16-year and 32-year scales, but they show nonlinear fluctuations at 2-year and 4-year scales. (3 The relationship between AR with AAT and AP was simulated by the multiple linear regression equation (MLRE based on wavelet analysis at each time scale. But the simulated effect at a larger time scale is better than that at a smaller time scale.

Long-range atmospheric transport and the distribution of polycyclic aromatic hydrocarbons in Changbai Mountain.

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Zhao, Xiangai; Kim, Seung-Kyu; Zhu, Weihong; Kannan, Narayanan; Li, Donghao

2015-01-01

The Changbai (also known as "Baekdu") Mountain, on the border between China and North Korea, is the highest mountain (2750 m) in northeastern China. Recently, this mountain region has experienced a dramatic increase in air pollution, not only because of increasing volumes of tourism-derived traffic but also because of the long-range transport of polluted westerly winds passing through major industrial and urban cities in the eastern region of China. To assess the relative importance of the two sources of pollution, 16 polycyclic aromatic hydrocarbons (PAHs) as model substances were determined in the mountain soil. A total of 32 soil samples were collected from different sides of the mountain at different latitudes between July and August of 2009. The ∑PAH concentrations were within the range 38.5-190.1 ng g(-1) on the northern side, 117.7-443.6 ng g(-1) on the southern side, and 75.3-437.3 ng g(-1) on the western side. A progressive increase in the level of ∑PAHs with latitude was observed on the southern and western sides that face the westerly wind with abundant precipitation. However, a similar concentration gradient was not observed on the northern side that receives less rain and is on the leeward direction of the wind. The high-molecular-weight PAH compounds were predominant in the soils on the southern and western sides, while low-molecular-weight PAHs dominated the northern side soils. These findings show that the distribution of PAHs in the mountain soil is strongly influenced by the atmospheric long-range transport and cold trapping. Copyright © 2014 Elsevier Ltd. All rights reserved.

Mountain pastures of Qilian Shan: plant communities, grazing impact and degradation status (Gansu province, NW China)

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Baranova, Alina; Schickhoff, Udo; Shunli, Wang; Ming, Jin

2015-04-01

Qilian Mountains are the water source region for the low arid reaches of HeiHe river basin (Gansu province, NW China). Due to overstocking and overgrazing during the last decades adverse ecological ef¬fects, in particular on soil properties and hydrological cycle, are to be expected in growing land areas. Vegetation cover is very important to prevent erosion process and to sustain stable subsurface runoff and ground water flow. The aim of this research is to identify plant communities, detecting grazing-induced and spatially differentiated changes in vegetation patterns, and to evaluate status of pasture land degradation.The study area is located in the spring/autumn pasture area of South Qilian Mountains between 2600-3600 m a.s.l., covering five main vegetation types: spruce forest, alpine shrubland, shrubby grassland, mountain grassland, degraded mountain grassland. In order to analyze gradual changes in vegetation patterns along altitudinal and grazing gradients and to classify related plant communities, quantitative and qualitative relevé data were collected (coverage, species composition, abundance of unpalatable plants, plant functional types, etc.). Vegetation was classified using hierarchical cluster analyses. Indirect Detrended Correspondence Analysis (DCA) was used to analyze variation in relationships between vegetation, environmental factors, and grazing impact. According to DCA results, distribution of the plant communities was strongly affected by altitude and exposition. Grassland floristic gradients showed greater dependence on grazing impact, which correlated contrarily with soil organic content, soil moisture and pH. Highest numbers of species richness and alpha diversity were detected in alpine shrubland vegetation type. Comparing the monitoring data for the recent nine years, a trend of deterioration, species successions and shift in dominant species becomes obvious. Species indicating degrading site environmental conditions were identified

Stratigraphy and paleogeographic significance of the Pennsylvanian-Permian Bird Spring Formation in the Ship Mountains, southeastern California

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Stone, Paul; Stevens, Calvin H.; Howard, Keith A.; Hoisch, Thomas D.

2013-01-01

A thick sequence of limestone, dolomite, and minor sandstone assigned to the Pennsylvanian and lower Permian Bird Spring Formation is exposed in the Ship Mountains about 85 kilometers (km) southwest of Needles, California, in the eastern Mojave Desert. These strata provide a valuable reference section of the Bird Spring Formation in a region where rocks of this age are not extensively exposed. This section, which is about 900 meters (m) thick, is divided into five informal members. Strata of the Bird Spring Formation in the Ship Mountains originated as shallow-water marine deposits on the broad, southwest-trending continental shelf of western North America. Perpendicular to the shelf, the paleogeographic position of the Ship Mountains section is intermediate between those of the thicker, less terrigenous, more seaward section of the Bird Spring Formation in the Providence Mountains, 55 km to the northwest, and the thinner, more terrigenous, more landward sections of the Supai Group near Blythe, 100 km to the southeast. Parallel to the shelf, the Ship Mountains section is comparable in lithofacies and inferred paleogeographic position to sections assigned to the Callville Limestone and overlying Pakoon Limestone in northwestern Arizona and southeastern Nevada, 250 km to the northeast. Deposition of the Bird Spring Formation followed a major rise in eustatic sea level at about the Mississippian- Pennsylvanian boundary. The subsequent depositional history was controlled by episodic changes in eustatic sea level, shelf subsidence rates, and sediment supply. Subsidence rates could have been influenced by coeval continental-margin tectonism to the northwest.

Understanding Educational Leadership in North-West China

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Militello, Matthew; Berger, Joseph B.

2010-01-01

The purpose of this study was to develop greater depth of understanding regarding educational leadership development in the five north-western provinces (Shaanxi, Xinjiang, Gansu, Qinghai and Ningxia) of the People's Republic of China. The researchers used a mixed method approach of surveys and focus group interviews to gather data regarding the…

Pore Effect on the Occurrence and Formation of Gas Hydrate in Permafrost of Qilian Mountain, Qinghai-Tibet Plateau, China

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Gao, H.; Lu, H.; Lu, Z.

2014-12-01

Gas hydrates were found in the permafrost of Qilian Mountain, Qinghai- Tibet Plateau, China in 2008. It has been found that gas hydrates occur in Jurassic sedimentary rocks, and the hydrated gases are mainly thermogenic. Different from the gas hydrates existing in loose sands in Mallik, Mackenzie Delta, Canada and North Slope, Alaska, USA, the gas hydrates in Qilian Mountain occurred in hard rocks. For understanding the occurrence and formation mechanism of gas hydrate in hard rcok, extensive experimental investigations have been conducted to study the pore features and hydrate formation in the rocks recovered from the hydrate layers in Qilian Mountain. The structures of sedimentary rock were observed by high-resolution X-ray CT, and pore size distribution of a rock specimen was measured with the mercury-injection method. Methane hydrate was synthesized in water-saturated rocks, and the saturations of hydrate in sedimentary rocks of various types were estimated from the amount of gas released from certain volume of rock. X-ray CT observation revealed that fractures were developed in the rocks associated with faults, while those away from faults were generally with massive structure. The mercury-injection analysis of pore features found that the porosities of the hydrate-existing rocks were generally less than 3%, and the pore sizes were generally smaller than 100 nm. The synthesizing experiments found that the saturation of methane hydrate were generally lower than 6% of pore space in rocks, but up to 16% when fractures developed. The low hydrate saturation in Qilian sedimentary rocks has been found mainly due to the small pore size of rock. The low hydrate saturation in the rocks might be the reason for the failure of regional seismic and logging detections of gas hydrates in Qilian Mountain.

Comparative analysis of essential oil components of two Pinus species from Taibai Mountain in China.

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Zhang, Yuan; Wang, Zhezhi

2010-08-01

Gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) were used to compare between the essential oil components from needles of Pinus armandii Franch versus P. tabulaeformis Carr., growing on the same site at Taibai Mountain, China. Under optimum extraction and analysis conditions, 65 and 66 constituents each were identified in P. armandii and P. tabulaeformis, which accounted for 87.9% and 87.1%, respectively, of their oils. Based on their terpene compositions, we concluded that these species belong to a high-caryophyllene chemotype, with sesquiterpenes comprising 54.4% to 54.8% of the total contents. We also determined minor qualitative and major quantitative variations in some compounds. Compared with that from P. tabulaeformis, P. armandii oil had more gamma-muurolene (7.5%), terpinolene (5.8%), and longifolene (5.7%). In contrast, alpha-pinene (8.6%) and caryophyllene oxide (7.4%) were the dominant compounds in P. tabulaeformis.

Seroprevalence and Risk Factors of Chlamydia abortus Infection in Tibetan Sheep in Gansu Province, Northwest China

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Si-Yuan Qin

2014-01-01

Full Text Available Chlamydia abortus, an important pathogen in a variety of animals, is associated with abortion in sheep. In the present study, 1732 blood samples, collected from Tibetan sheep between June 2013 and April 2014, were examined by the indirect hemagglutination (IHA test, aiming to evaluate the seroprevalence and risk factors of C. abortus infection in Tibetan sheep. 323 of 1732 (18.65% samples were seropositive for C. abortus antibodies at the cut-off of 1 : 16. A multivariate logistic regression analysis was used to evaluate the risk factors associated with seroprevalence, which could provide foundation to prevent and control C. abortus infection in Tibetan sheep. Gender of Tibetan sheep was left out of the final model because it is not significant in the logistic regression analysis (P>0.05. Region, season, and age were considered as major risk factors associated with C. abortus infection in Tibetan sheep. Our study revealed a widespread and high prevalence of C. abortus infection in Tibetan sheep in Gansu province, northwest China, with higher exposure risk in different seasons and ages and distinct geographical distribution.

Variation of NEE and its affecting factors in a vineyard of arid region of northwest China

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Guo, W. H.; Kang, S. Z.; Li, F. S.; Li, S. E.

2014-02-01

To understand the variation of net ecosystem CO2 exchange (NEE) in orchard ecosystem and it's affecting factors, carbon flux was measured using eddy covariance system in a wine vineyard in arid northwest China during 2008-2010. Results show that vineyard NEE was positive value at the early growth stage, higher negative value at the mid-growth stage, and lower negative value at the later growth stage. Diurnal variation of NEE was "W" shaped curve in sunny day, but "U" shaped curve in cloudy day. Irrigation and pruning did not affect diurnal variation shape of NEE, however, irrigation reduced the difference between maximal and minimal value of NEE and pruning reduced the carbon sink capacity. The main factors affecting hourly NEE were canopy conductance (gc) and net radiation (Rn). The hourly NEE increased with the increase of gc or Rn when gc was less than 0.02 m·s-1 or Rn was between 0 and 200 W·m-2. The main factors affecting both daily and seasonal NEE were gc, air temperature (Ta), atmospheric CO2 density, vapour pressure deficit (VPD) and soil moisture content.

Direct regional quasi-geoid determination using EGM2008 and DEM: A case study for Mainland China and its vicinity areas

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Jin Li

2015-11-01

Full Text Available Earth's gravity model (EGM helps people better determine the figure of Earth, which is generally represented by a global geoid. For a considerable amount of practical applications, people use quasi-geoid to approximate the geoid, thus the quasi-geoid is also treated as an important height datum. In this study we revisit the method to directly determine regional quasi-geoid using EGM and digital elevation model (DEM, on the basis of Molodensky theory. According to the method we obtain a 5′ × 5′ quasi-geoid for Mainland China and its vicinity areas, based on the EGM2008 gravitational potential model and the Shuttle Radar Topography Mission (SRTM DEM model. By comparing height anomalies derived from EGM2008 with observations at 70 GPS/leveling points in areas including northwest, mid-west, mid-east and southeast of China, we find that the 5′ × 5′ EGM2008 quasi-geoid well fits the GPS/leveling results, with average deviations less than 10 cm for the selected areas in east China (with mainly plain topography and ∼20 cm for the selected areas in west China (highland or mountainous areas. We also discuss a few technical issues for directly determining height anomalies based on EGM and DEM, under the frame of Molodensky theory.

The origin of high hydrocarbon groundwater in shallow Triassic aquifer in Northwest Guizhou, China.

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Liu, Shan; Qi, Shihua; Luo, Zhaohui; Liu, Fangzhi; Ding, Yang; Huang, Huanfang; Chen, Zhihua; Cheng, Shenggao

2018-02-01

Original high hydrocarbon groundwater represents a kind of groundwater in which hydrocarbon concentration exceeds 0.05 mg/L. The original high hydrocarbon will significantly reduce the environment capacity of hydrocarbon and lead environmental problems. For the past 5 years, we have carried out for a long-term monitoring of groundwater in shallow Triassic aquifer in Northwest Guizhou, China. We found the concentration of petroleum hydrocarbon was always above 0.05 mg/L. The low-level anthropogenic contamination cannot produce high hydrocarbon groundwater in the area. By using hydrocarbon potential, geochemistry and biomarker characteristic in rocks and shallow groundwater, we carried out a comprehensive study in Dalongjing (DLJ) groundwater system to determine the hydrocarbon source. We found a simplex hydrogeology setting, high-level water-rock-hydrocarbon interaction and obviously original hydrocarbon groundwater in DLJ system. The concentration of petroleum hydrocarbon in shallow aquifer was found to increase with the strong water-rock interaction. Higher hydrocarbon potential was found in the upper of Guanling formation (T 2 g 3 ) and upper of Yongningzhen formation (T 1 yn 4 ). Heavily saturated carbon was observed from shallow groundwater, which presented similar distribution to those from rocks, especially from the deeper groundwater. These results indicated that the high concentrations of original hydrocarbon in groundwater could be due to the hydrocarbon release from corrosion and extraction out of strata over time.

Astragalus kongrensis Benth. Ex Baker (Fabaceae, a New Record for Central and North-West Himalayas

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Lal Babu Chaudhary

2006-09-01

Full Text Available Astragalus kongrensis Benth. Ex Baker is reported for the first time from Central (Nepal and North-West Himalayas (India. Earlier the species was known from East Himalaya (Sikkim-India, Bhutan and China. The description and illustrations of the species are provided.

Dynamics of Coarse Woody Debris Characteristics in the Qinling Mountain Forests in China

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Jie Yuan

2017-10-01

Full Text Available Coarse woody debris (CWD is an essential component in defining the structure and function of forest ecosystems. Long-term dynamics of CWD characteristics not only affect the release rates of chemical elements from CWD, but also the species diversity of inhabiting plants, animals, insects, and microorganisms as well as the overall health of ecosystems. However, few quantitative studies have been done on the long-term dynamics of CWD characteristics in forest ecosystems in China. In this study, we conducted nine tree censuses between 1996 and 2016 at the Huoditang Experimental Forest in the Qinling Mountains of China. We quantified forest biomass including CWD and CWD characteristics such as decay states and diameter classes during this period and correlated with stand, site, and climatic variables. The forest biomass was dominated by live tree biomass (88%; followed by CWD mass (6%–10%. Understory biomass contributed only a small portion (1%–4% of the overall biomass. Significant differences in average annual increment of CWD mass were found among forest stands of different species (p < 0.0001. Forest biomass, stand age, forest type, aspect, slope, stand density, annual average temperature, and precipitation were all significantly correlated with CWD mass (p < 0.05, with forest type exhibiting the strongest correlation (r2 = 0.8256. Over time, the annual mass of different CWD characteristics increased linearly from 1996–2016 across all forest types. Our study revealed that forest biomass, including CWD characteristics, varied by forest type. Stand and site characteristics (forest biomass, forest type, aspect, slope and stand density along with temperature and precipitation played a major role in the dynamics of CWD in the studied forest ecosystems.

How Universities Work: Understanding Higher Education Organization in Northwest China

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Berger, Joseph B.; Hudson, Katherine E.; Ramirez, Gerardo Blanco

2013-01-01

This study explores models of educational management used in postsecondary institutions in the five northwestern provinces of the People's Republic of China (Gansu, Ningxia, Qinghai, Shaanxi, and Xinjiang). As higher education in the People's Republic of China expands and undergoes significant changes, a nuanced understanding of the organizational…

Genetic diversity of Haemonchus contortus isolated from sympatric wild blue sheep (Pseudois nayaur) and sheep in Helan Mountains, China.

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Shen, Dong-Dong; Wang, Ji-Fei; Zhang, Dan-Yu; Peng, Zhi-Wei; Yang, Tian-Yun; Wang, Zhao-Ding; Bowman, Dwight D; Hou, Zhi-Jun; Liu, Zhen-Sheng

2017-09-19

Haemonchus contortus is known among parasitic nematodes as one of the major veterinary pathogens of small ruminants and results in great economic losses worldwide. Human activities, such as the sympatric grazing of wild with domestic animals, may place susceptible wildlife hosts at risk of increased prevalence and infection intensity with this common small ruminant parasite. Studies on phylogenetic factors of H. contortus should assist in defining the amount of the impact of anthropogenic factors on the extent of sharing of agents such as this nematode between domestic animals and wildlife. H. contortus specimens (n = 57) were isolated from wild blue sheep (Pseudois nayaur) inhabiting Helan Mountains (HM), China and additional H. contortus specimens (n = 20) were isolated from domestic sheep that were grazed near the natural habitat of the blue sheep. Complete ITS2 (second internal transcribed spacer) sequences and partial sequences of the nad4 (nicotinamide dehydrogenase subunit 4 gene) gene were amplified to determine the sequence variations and population genetic diversities between these two populations. Also, 142 nad4 haplotype sequences of H. contortus from seven other geographical regions of China were retrieved from database to further examine the H. contortus population structure. Sequence analysis revealed 10 genotypes (ITS2) and 73 haplotypes (nad4) among the 77 specimens, with nucleotide diversities of 0.007 and 0.021, respectively, similar to previous studies in other countries, such as Pakistan, Malaysia and Yemen. Phylogenetic analyses (BI, MP, NJ) of nad4 sequences showed that there were no noticeable boundaries among H. contortus populations from different geographical origin and population genetic analyses revealed that most of the variation (94.21%) occurred within H. contortus populations. All phylogenetic analyses indicated that there was little genetic differentiation but a high degree of gene flow among the H. contortus populations among

Relations between red beds times and uranic mineralization at the area of north-west China, Shaanxi and Inner Mongolia

International Nuclear Information System (INIS)

Zhou Qiaosheng; Quan Zhigao

1989-04-01

Rad beds played an important role in the uranic mineralization. After analyzing the geological evolution in North-West China, Saanxi and Inner Mongolia the red beds is divided into six periods. The evolution rules at each period are studied. The authors found that the time of uranic mineralication and formation of red beds (basin) is simultaneously, the uranic deposits and red beds are accompanying minerals in all places existing deposits. Uranic mineralization is bound up with the continental red beds which was formed under dry and hot climate, but has no relations with the marine red beds. The place where the deposits exist, the red beds must exist, conversely it is not true. In the section, a big uranic deposit is generated only under or above the red beds. The relations between red beds and rich deposit are also explored. The mineralization theory and the model of uranic mineralization in red beds times are presented

Quaternary tectonic evolution of the Pamir-Tian Shan convergence zone, Northwest China

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Thompson Jobe, Jessica Ann; Li, Tao; Chen, Jie; Burbank, Douglas W.; Bufe, Aaron

2017-12-01

The Pamir-Tian Shan collision zone in the western Tarim Basin, northwest China, formed from rapid and ongoing convergence in response to the Indo-Eurasian collision. The arid landscape preserves suites of fluvial terraces crossing structures active since the late Neogene that create fault and fold scarps recording Quaternary deformation. Using geologic and geomorphic mapping, differential GPS surveys of deformed terraces, and optically stimulated luminescence dating, we create a synthesis of the active structures that delineate the timing, rate, and migration of Quaternary deformation during ongoing convergence. New deformation rates on eight faults and folds, when combined with previous studies, highlight the spatial and temporal patterns of deformation within the Pamir-Tian Shan convergence zone during the Quaternary. Terraces spanning 130 to 8 ka record deformation rates between 0.1 and 5.6 mm/yr on individual structures. In the westernmost Tarim Basin, where the Pamir and Tian Shan are already juxtaposed, the fastest rates occur on actively deforming structures at the interface of the Pamir-Tian Shan orogens. Farther east, as the separation between the Pamir-Tian Shan orogens increases, the deformation has not been concentrated on a single structure, but rather has been concurrently distributed across a zone of faults and folds in the Kashi-Atushi fold-and-thrust belt and along the NE Pamir margin, where shortening rates vary on individual structures during the Quaternary. Although numerous structures accommodate the shortening and the locus of deformation shifts during the Quaternary, the total shortening across the western Tarim Basin has remained steady and approximately matches the current geodetic rate of 6-9 mm/yr.

State-Led Ecotourism Development and Nature Conservation: a Case Study of the Changbai Mountain Biosphere Reserve, China

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Jianqiong Yuan

2008-12-01

Full Text Available Faced with fiscal constraints and enormous population pressures, 80% of Chinese nature reserves have employed ecotourism as a support and development strategy. Assessing the actual effects of ecotourism at a nature reserve that has a relatively long history of ecotourism development experience may be instructive for other reserves. Therefore, we take Changbai Mountain Biosphere Reserve (CMBR in northeastern China as a case study, for it is one of the pioneers in embracing ecotourism in China. Personal interviews and informal group discussions were employed to understand local residents' attitudes toward conservation. Factors affecting their attitudes were then analyzed using logistic regression. Results indicate that attitudes held by most farmers are not favorable toward the conservation of the CMBR. It is not ecotourism but rather income from collection of forest products, household crop lands, and migrant labor that actually influences their attitudes. We found that the 1-day-sightseeing tour style, the limited tourism period, and the low level of education and extreme poverty of the local residents, together with existing institutions and lagging regulations make it very difficult for ecotourism to engender local residents' support. We concluded that institutional measures to guarantee local people's sharing in the revenue generated by the reserve, as well as regulations to ensure involvement of the local community in the decision-making process are preconditions for ecotourism to engender local support in China. Providing educational opportunities for children and vocational training for young local residents can also contribute indirectly to enhanced conservation.

Recent atmospheric lead deposition recorded in an ombrotrophic peat bog of Great Hinggan Mountains, Northeast China, from 210Pb and 137Cs dating

International Nuclear Information System (INIS)

Bao, K.; Xia, W.; Lu, X.; Wang, G.

2010-01-01

Radioactive markers are useful in dating lead deposition patterns from industrialization in peat archive. Peat cores were collected in an ombrotrophic peat bog in the Great Hinggan Mountains in Northeast China in September 2008 and dated using 210 Pb and 137 Cs radiometric techniques. The mosses in both cores were examined systematically for dry bulk density, water and ash content. Lead also was measured using atomic emission spectroscopy with inductively coupled plasma (ICP-AES). Both patterned peat profiles were preserved well without evident anthropogenic disturbance. Unsupported 210 Pb and 137 Cs decreased with the depth in both of the two sample cores. The 210 Pb chronologies were established using the constant rate of supply model (CRS) and are in good agreement with the 137 Cs time marker. Recent atmospheric 210 Pb flux in Great Hinggan Mountains peat bog was estimated to be 337 Bq m -2 y -1 , which is consistent with published data for the region. Lead deposition rate in this region was also derived from these two peat cores and ranged from 24.6 to 55.8 mg m -2 y -1 with a range of Pb concentration of 14-262 μg g -1 . The Pb deposition patterns were consistent with increasing industrialization over the last 135-170 y, with a peak of production and coal burning in the last 50 y in Northeast China. This work presents a first estimation of atmospheric Pb deposition rate in peatlands in China and suggests an increasing trend of environmental pollution due to anthropogenic contaminants in the atmosphere. More attention should be paid to current local pollution problems, and society should take actions to seek a balance between economic development and environmental protection.

Pollution of intensively managed greenhouse soils by nutrients and heavy metals in the Yellow River Irrigation Region, Northwest China.

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Kong, Xiaole; Cao, Jing; Tang, Rangyun; Zhang, Shengqiang; Dong, Fang

2014-11-01

The present study aimed to assess the potential ecological risk of heavy metals and nutrient accumulation in polytunnel greenhouse soils in the Yellow River irrigation region (YRIR), Northwest China, and to identify the potential sources of these heavy metals using principal component analysis. Contents of available nitrogen (AN), phosphorus (AP), and potassium (AK) in the surface polytunnel greenhouse soils (0-20 cm) varied from 13.42 to 486.78, from 39.10 to 566.97, and from 21.64 to 1,156.40 mg kg(-1), respectively, as well as AP, soil organic matter (SOM) and AK contents tended to increase significantly at the 0-20- and 20-40-cm soil layers. Heavy metal accumulations occurred in the polytunnel greenhouse soils as compared to arable soils, especially at a depth of 20 cm where Cd, Zn and Cu contents were significantly higher than arable soil. Cd and As were found to be the two main polluting elements in the greenhouse soils because their contents exceeded the thresholds established for greenhouse vegetable production HJ333-2006 in China and the background of Gansu province. It has been shown that Cd, Cu, Pb and Zn at the 0-20-cm soil layer were derived mainly from agricultural production activities, whereas contents of Cr and Ni at the same soil layer were determined by 'natural' factors and As originated from natural sources, deposition and irrigation water.

[Ecological and economic harmony evaluation and spatial evolution of the Hexi corridor, northwest China].

Science.gov (United States)

Liu, Hai-long; Shi, Pei-ji; Li, Sheng-mei; Tong, Hua-li; Nie, Xiao-ying; Wei, Wei

2014-12-01

The relationship between economic development and environment and the evolution characteristics of spatial pattern in Hexi Corridor of Northwest China were analyzed based on Landsat images in 1985, 1995, 2000 and 2011 with twenty counties in Hexi Corridor chosen as the basic research units. The ecological economic harmony during 1985-2011 was estimated according to ESV (ecosystem services value) and EEH (ecological and economic harmony) index with the ecosystem services value estimation methods. The results showed that the land type of the study area dramatically changed during the study period, the grassland decreased badly, and the construction land and cultivated land increased quickly. The ESV showed an overall downward trend, especially in the Shiyang River basin and the middle of Heihe River. The ESV in the Shule River basin in this period. After 2000, the economic growth speeded up visibly in the study area. The economic development concentrated in the resource-based cities and regional central cities, and declined from the center of corridor to the both sides. The ecological-economic relation in Hexi Corridor experienced a transformation of "preliminary deterioration--further deterioration--low grade coordination". The EEH had large changes in the Shiyang River basin and the middle of Heihe River, which experienced a transformation of "conflict--more conflicts--less conflicts", however, there was little change in Shule River basin. The development mode and the comprehensive reclamation of Shiyang River basin and Heihe River basin had a significant influence on the regional ecological and economic harmony.

Development of a Severe Sand-dust Storm Model and its Application to Northwest China

International Nuclear Information System (INIS)

Zhang Xiaoling; Cheng, Linsheng; Chung, Yong-Seung

2003-01-01

A very strong sand-dust storm occurred on 5 May, 1993 in Northwest China. In order to give a detailed description of the evolution of a mesoscale system along with the heavy sand-dust storm, a complex model including improved physical processes and a radiation parameterization scheme was developed based on a simulation model. The improved model introduced a sand-dust transport equation as well as a lifting transport model, sand-dust aerosols and radiation parameterization scheme.Using this model, the super sand-dust storm case on 5 May was simulated. Results indicated that the coupled mesoscale model successfully simulated the mesoscale vortex, its strong upward movement and the warm core structure of PBL. The generation and development of these structures were consistent with that of the sand-dust storm and dry squall-line (which was different with normal squall-line). Simulated sand-dust concentration and its radiative effect corresponded with observation data. The radiative effect of sand-dust aerosols caused the air to heat on the top of aerosol layer with a heating rate amounting to 2 K hr -1 . As a result, solar radiation flux that reached the surface, net radiation flux and surface temperature all suddenly went down. The temperature gradient across the cold front became obviously larger. Therefore, enhancing the development of the mesoscale system. The simulation generally reflected features during the squall-line passage of this strong sand-dust storm

The red bed-type and sandstone-type uranium deposits in the inland basins of the northwest China

International Nuclear Information System (INIS)

Wang Zhilong.

1988-01-01

On the basis of the study on the relationship between the red bed-type and sandstone-type uranium deposits in the inland basins of the northwest China, a classification of red beds based on sedimentary facies and redding origin is presented. Red beds in the inland badins can be divided into six types: 1. alluvial plain and 2. shallow lake red beds formed at the stage of continental disintegration; 3. fluvial alluvial red bed, 4. delta plain and 5. desert red beds formed at the diagenetic-epigenetic stage; 6. spattered red (secondaty red beds) formed at the hypergenic weathering stage. According to the characteristics, structural environments of these six types of red beds, and changes of various geochemical characteristic values (Eh, pH, Th/U, Fe 3+ /Fe 2+ , Sr/Ba, etc.) from host rocks to different kinds of red beds , the relationship between these values and sandstone-type uranium deposits was determined. it is an open system, the mobile uranium is easily leached, thus it is unfavoutable for mineralization; but when the rock reddens at the diagenetic epigenetic stage (closed system) that is favourable for mineraizaltion, the mobile uranium can be concentrated to form uranium deposits

Regional Disparities in Emissions of Rural Household Energy Consumption: A Case Study of Northwest China

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Wenheng Wu

2017-05-01

Full Text Available The purpose of this paper is to present the emissions status of multiple rural areas from the perspective of a field survey and make up for the defects of the traditional emission cognition of single type of area. The basic data in the lower reaches of the Weihe River of Northwest China were collected through household questionnaire surveys, and emissions from rural household energy consumption were calculated in the paper. In addition, the grey relational analysis method was used to identify influential factors of emission disparities. The results show that the total emissions of the plain, loess tableland, and Qinling piedmont areas are 1863.20, 1850.43, and 2556.68 kg, respectively. Regional disparities in emissions of rural household energy consumption vary greatly. CO2 emissions are highest in the Qinling piedmont area, followed by the loess tableland area. For other emissions, there is no fixed order of the three areas, which suggests that disparities in emissions are connected with the dominant type of energy consumption. Diversification of energy use might not necessarily produce higher emissions, but the traditional biomass energy pattern does generate more emissions. The regional supply capacity of household energy is the original influence factor of disparities in emissions, and factors that influence these disparities are directly related to differences among farmers, followed by the age structure, educational background, income level, occupation, and so on.

Simulating the Effect of Climate Change on Vegetation Zone Distribution on the Loess Plateau, Northwest China

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Guoqing Li

2015-06-01

Full Text Available A risk assessment of vegetation zone responses to climate change was conducted using the classical Holdridge life zone model on the Loess Plateau of Northwest China. The results show that there are currently ten vegetation zones occurring on the Loess Plateau (1950–2000, including alvar desert, alpine wet tundra, alpine rain tundra, boreal moist forest, boreal wet forest, cool temperate desert, cool temperate desert scrub, cool temperate steppe, cool temperate moist forest, warm temperate desert scrub, warm temperate thorn steppe, and warm temperate dry forest. Seventy years later (2070S, the alvar desert, the alpine wet tundra and the cool temperate desert will disappear, while warm temperate desert scrub and warm temperate thorn steppe will emerge. The area proportion of warm temperate dry forest will expand from 12.2% to 22.8%–37.2%, while that of cool temperate moist forest will decrease from 18.5% to 6.9%–9.5%. The area proportion of cool temperate steppe will decrease from 51.8% to 34.5%–51.6%. Our results suggest that future climate change will be conducive to the growth and expansion of forest zones on the Loess Plateau, which can provide valuable reference information for regional vegetation restoration planning and adaptive strategies in this region.

From a Yunnan mountain to a Tibetan highland-the story of a hundred years of cosmic ray research in China

International Nuclear Information System (INIS)

Tan Youheng

2013-01-01

The discovery of cosmic rays a hundred years ago opened a new field of view to the universe and the mysterious particle world, leading to the birth of particle physics. Cosmic ray research in China was started in the early 50's of the last century by several senior scientists who had already distinguished themselves abroad in this subject. The first cosmic ray observatory in China was built on a mountain in Yunnan province, and many high level results were obtained in the ensuing ten years. Then after almost twenty years of political unrest, the national 'Reform and Opening up' policy provided a good opportunity to stimulate development and to narrow the wide gap caused by long term stagnation. The second generation of Chinese cosmic ray researchers chose high altitude extensive air showers as their new target of observation, and embarked on twenty years of hard work to build a modern international cosmic ray experimental station at Yangbajing in Tibet, 4300 m above sea level. The manually operated cloud chamber was transformed into a large-scale high-technology facility , capable of performing various international research programs with its unique low threshold energy, high trigger rate and wide field of view. The Yanbajing Observatory symbolizes that China's cosmic ray research has started on a new march towards excellence. (author)

Genetic variation of the endangered Gentiana lutea L. var. aurantiaca (Gentianaceae) in populations from the Northwest Iberian Peninsula.

Science.gov (United States)

González-López, Oscar; Polanco, Carlos; György, Zsuzsanna; Pedryc, Andrzej; Casquero, Pedro A

2014-06-05

Gentiana lutea L. (G. lutea L.) is an endangered plant, patchily distributed along the mountains of Central and Southern Europe. In this study, inter-simple sequence repeat (ISSR) markers were used to investigate the genetic variation in this species within and among populations of G. lutea L. var. aurantiaca of the Cantabrian Mountains (Northwest Iberian Peninsula). Samples of G. lutea L. collected at different locations of the Pyrenees and samples of G. lutea L. subsp. vardjanii of the Dolomites Alps were also analyzed for comparison. Using nine ISSR primers, 106 bands were generated, and 89.6% of those were polymorphic. The populations from the Northwest Iberian Peninsula were clustered in three different groups, with a significant correlation between genetic and geographic distances. Gentiana lutea L. var. aurantiaca showed 19.8% private loci and demonstrated a remarkable level of genetic variation, both among populations and within populations; those populations with the highest level of isolation show the lowest genetic variation within populations. The low number of individuals, as well as the observed genetic structure of the analyzed populations makes it necessary to protect them to ensure their survival before they are too small to persist naturally.

Genetic Variation of the Endangered Gentiana lutea L. var. aurantiaca (Gentianaceae in Populations from the Northwest Iberian Peninsula

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Oscar González-López

2014-06-01

Full Text Available Gentiana lutea L. (G. lutea L. is an endangered plant, patchily distributed along the mountains of Central and Southern Europe. In this study, inter-simple sequence repeat (ISSR markers were used to investigate the genetic variation in this species within and among populations of G. lutea L. var. aurantiaca of the Cantabrian Mountains (Northwest Iberian Peninsula. Samples of G. lutea L. collected at different locations of the Pyrenees and samples of G. lutea L. subsp. vardjanii of the Dolomites Alps were also analyzed for comparison. Using nine ISSR primers, 106 bands were generated, and 89.6% of those were polymorphic. The populations from the Northwest Iberian Peninsula were clustered in three different groups, with a significant correlation between genetic and geographic distances. Gentiana lutea L. var. aurantiaca showed 19.8% private loci and demonstrated a remarkable level of genetic variation, both among populations and within populations; those populations with the highest level of isolation show the lowest genetic variation within populations. The low number of individuals, as well as the observed genetic structure of the analyzed populations makes it necessary to protect them to ensure their survival before they are too small to persist naturally.

[Predicting the impact of global warming on the geographical distribution pattern of Quercus variabilis in China].

Science.gov (United States)

Li, Yao; Zhang, Xing-wang; Fang, Yan-ming

2014-12-01

The geographical distribution of Quercus variabilis in China with its climate characteristics was analyzed based on DIVA-GIS which was also used to estimate the response of future potential distribution to global warming by Bioclim and Domain models. Analysis results showed the geographical distribution of Q. variabilis could be divided into 7 subregions: Henduan Mountains, Yunnan-Guizhou Plateau, North China, East China, Liaodong-Shandong Peninsula, Taiwan Island, and Qinling-Daba Mountains. These subregions are across 7 temperature zones, 2 moisture regions and 17 climatic subregions, including 8 climate types. The modern abundance center of Q. variabilis is Qinling, Daba and Funiu mountains. The condition of mean annual temperature 7.5-19.8 degrees C annual precipitation 471-1511 mm, is suitable for Q. variabilis. Areas under the receiver operating characteristic curve (AUC values), of Domain and Boiclim models were 0.910, 0.779; the former predicted that the potential regions of high suitability for Q. variabilis are Qinling, Daba, Funiu, Tongbai, and Dabie mountains, eastern and western Yunnan-Guizhou Plateau, hills of southern Jiangsu and Anhui, part of the mountains in North China. Global warming might lead to the shrinking in suitable region and retreating from the south for Q. variabilis.

Human settlement and its influencing factors during the historicalperiod in an oasis-desert transition zone of Dunhuang, Hexi Corridor,northwest China

Science.gov (United States)

Li, H.; Dong, G.; Zhang, S.

2017-12-01

Many ancient cities and settlement sites have been found in Lucaogou, an ancient oasis near Dunhuangcity in northwest China. These settlements indicate that humans inhabited this area during the historicalperiod. However, the chronology and subsistence practices of this area remain unclear. Based on newdata from radiocarbon dating, macrobotanical analysis, and the synthesis of historical documents andhigh-resolution paleoclimatic records, we discuss the inter-relationship between human settlements andplant resource utilization strategies at Lucaogou ancient oasis during historical period. Our resultsindicate that these ancient sites in Lucaogou area were built between the Han dynasty (202 BC-AD 220)and the Ming dynasty (AD 1368-AD 1644). People mainly used foxtail millet, broomcorn millet, barleyand three types of wood (Tamarix, Salix, Populus), probably as fuel for cooking. Human settlement intensityin the area during the historical period was primarily influenced by political situations, whichmight also have been affected by fluctuations in precipitation.

Factors affecting soil erosion in Beijing mountain forestlands | Zhang ...

African Journals Online (AJOL)

The role of regions, vegetation types and forest stand density in controlling soil erosion were investigated in Beijing mountain forest, China. The main objective was to develop some models to estimate soil erosion under different forest conditions including regions, vegetation type, and stand density as influenced by artificial ...

Responses of terrestrial ecosystems' net primary productivity to future regional climate change in China.

Science.gov (United States)

Zhao, Dongsheng; Wu, Shaohong; Yin, Yunhe

2013-01-01

The impact of regional climate change on net primary productivity (NPP) is an important aspect in the study of ecosystems' response to global climate change. China's ecosystems are very sensitive to climate change owing to the influence of the East Asian monsoon. The Lund-Potsdam-Jena Dynamic Global Vegetation Model for China (LPJ-CN), a global dynamical vegetation model developed for China's terrestrial ecosystems, was applied in this study to simulate the NPP changes affected by future climate change. As the LPJ-CN model is based on natural vegetation, the simulation in this study did not consider the influence of anthropogenic activities. Results suggest that future climate change would have adverse effects on natural ecosystems, with NPP tending to decrease in eastern China, particularly in the temperate and warm temperate regions. NPP would increase in western China, with a concentration in the Tibetan Plateau and the northwest arid regions. The increasing trend in NPP in western China and the decreasing trend in eastern China would be further enhanced by the warming climate. The spatial distribution of NPP, which declines from the southeast coast to the northwest inland, would have minimal variation under scenarios of climate change.

Responses of terrestrial ecosystems' net primary productivity to future regional climate change in China.

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Dongsheng Zhao

Full Text Available The impact of regional climate change on net primary productivity (NPP is an important aspect in the study of ecosystems' response to global climate change. China's ecosystems are very sensitive to climate change owing to the influence of the East Asian monsoon. The Lund-Potsdam-Jena Dynamic Global Vegetation Model for China (LPJ-CN, a global dynamical vegetation model developed for China's terrestrial ecosystems, was applied in this study to simulate the NPP changes affected by future climate change. As the LPJ-CN model is based on natural vegetation, the simulation in this study did not consider the influence of anthropogenic activities. Results suggest that future climate change would have adverse effects on natural ecosystems, with NPP tending to decrease in eastern China, particularly in the temperate and warm temperate regions. NPP would increase in western China, with a concentration in the Tibetan Plateau and the northwest arid regions. The increasing trend in NPP in western China and the decreasing trend in eastern China would be further enhanced by the warming climate. The spatial distribution of NPP, which declines from the southeast coast to the northwest inland, would have minimal variation under scenarios of climate change.

Late Quaternary palaeoecological and palaeoclimatological reconstruction in the Gutaiului Mountains, northwest Romania

Science.gov (United States)

Feurdean, Angelica; Bennike, Ole

2004-12-01

Macrofossil, pollen, lithostratigraphy, mineral magnetic measurements (SIRM and magnetic susceptibility), loss-on-ignition, and AMS radiocarbon dating on sediments from two former crater lakes, situated at moderate altitudes in the Gutaiului Mountains of northwest Romania, allow reconstruction of Late Quaternary climate and environment. Shrubs and herbs with steppe and montane affinities along with stands of Betula and Pinus, colonised the surroundings of the sites prior to 14 700 cal. yr BP and the inferred climatic conditions were cold and dry. The gradual transition to open Pinus-Betula forests, slightly higher lake water temperatures, and higher lake productivity, indicate more stable environmental conditions between 14 700 and 14 100 cal. yr BP. This development was interrupted by cooler and drier climatic conditions between 14 100 and 13 800 cal. yr BP, as inferred from a reduction of open forests to patches, or stands, of Pinus, Betula, Larix, Salix and Populus. The expansion of a denser boreal forest, dominated by Picea, but including Pinus, Larix, Betula, Salix, and Ulmus started at 13 800 cal. yr BP, although the forest density seems to have been reduced between 13400 and 13200cal.yrBP. Air temperature and moisture availability gradually increased, but a change towards drier conditions is seen at 13400cal.yrBP. A distinct decrease in temperature and humidity between 12900 and 11500cal.yrBP led to a return of open vegetation, with patches of Betula, Larix, Salix, Pinus and Alnus and individuals of Picea. Macrofossils and pollen of aquatic plants indicate rising lake water temperatures and increased aquatic productivity already by ca. 11800cal.yrBP, 300 years earlier than documented by the terrestrial plant communities. At the onset of the Holocene, 11500cal.yrBP, forests dominated by Betula, Pinus and Larix expanded and were followed by dense Ulmus forests with Picea, Betula and Pinus at 11250cal.yrBP. Larix pollen was not found, but macrofossil evidence

Tectonic uplift-influenced monsoonal changes promoted hominin occupation of the Luonan Basin: Insights from a loess-paleosol sequence, eastern Qinling Mountains, central China

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Fang, Qian; Hong, Hanlie; Zhao, Lulu; Furnes, Harald; Lu, Huayu; Han, Wen; Liu, Yao; Jia, Zhuoyue; Wang, Chaowen; Yin, Ke; Algeo, Thomas J.

2017-08-01

Quaternary soil deposits from northern and southern China are distinctly different, reflecting variability of the East Asian monsoon north and south of the Qinling Mountains. Coeval sediments from the transitional climatic zone of central China, which are little studied to date, have the potential to improve our understanding of Quaternary monsoon changes and associated influences on hominin occupation of this region. Here, we investigate in detail a well-preserved and continuous Quaternary loess-paleosol sequence (Shangbaichuan) from the Luonan Basin, using a variety of weathering indices including major and trace element ratios, clay mineralogy, and Fe-oxide mineralogy. The whole-rock samples display similar rare earth element patterns characterized by upper continental crustal ratios: (La/Yb)N ≈ 9.5 and Eu/Eu* ≈ 0.65. Elemental data such as (La/Yb)N, La/Th and Eu/Eu* ratios show a high degree of homogeneity, suggesting that dust in the source region may have been thoroughly mixed and recycled, resulting in all samples having a uniform initial composition. Indices for pedogenic weathering such as Na/K, Ba/Sr, Rb/Sr, CIA, CIW, CPA, PIA, kaolinite/illite, (kaolinite + smectite)/illite, and hematite/(hematite + goethite) exhibit similar secular trends and reveal a four-stage accumulation history. The indices also indicate that the climate was warmer and wetter during the most recent interglacial stage, compared with coeval environments of the Chinese Loess Plateau. Secular changes in weathering intensity can be related to stepwise uplift of the Qinling Mountains and variation in East Asian monsoon intensity, both of which played significant roles in controlling climate evolution in the Luonan Basin. Furthermore, intensified aridity and winter monsoon strength in dust source areas, as evidenced by mineralogic and geochemical changes, may have been due to the mid-Pleistocene climate transition. Based on temporal correlation of warmer and wetter climatic conditions

Riverine CO2 supersaturation and outgassing in a subtropical monsoonal mountainous area (Three Gorges Reservoir Region) of China

Science.gov (United States)

Li, Siyue; Ni, Maofei; Mao, Rong; Bush, Richard T.

2018-03-01

Rivers are an important source of CO2 to the atmosphere, however, mountainous rivers and streams with high emission rates are not well studied particularly in China. We report the first detailed investigation on monsoonal mountainous rivers in the Three Gorges Reservoir (TGR) region, with a focus on the riverine CO2 partial pressure (pCO2), CO2 degassing and their potential controls. The pCO2 levels ranged from 50 to 6019 μatm with averages of 1573 (SD. ±1060) in dry Autumn and 1276 (SD. ±1166) μatm in wet Summer seasons. 94% of samples were supersaturated with CO2 with respect to the atmospheric equilibrium (410 μatm). Monsoonal precipitation controlled pCO2 seasonality, with both the maximal and minimal levels occurring in the wet season, and showing the overall effects of dilution. Riverine pCO2 could be predicted better in the dry season using pH, DO% and DTP, whereas pH and DOC were better predictors in the wet season. We conclude that in-situ respiration of allochthonous organic carbon, rather than photosynthesis, resulted in negative relationships between pCO2 and DO and pH, and thus CO2 supersaturation. Photosynthetic primary production was effectively limited by rapid flow velocity and short residence time. The estimated water-to-air CO2 emission rate in the TGR rivers was 350 ± 319 in the Autumn and lower, yet more variable at 326 ± 439 mmol/m2/d in Summer. Our calculated CO2 areal fluxes were in the upper-level magnitude of published data, demonstrating the importance of mountainous rivers and streams as a global greenhouse gas source, and urgency for more detailed studies on CO2 degassing, to address a global data gap for these environments.

An Analysis of Rural Household Livelihood Change and the Regional Effect in a Western Impoverished Mountainous Area of China

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Chuansheng Wang

2018-05-01

Full Text Available Taking Longnan, in the western Qinling Mountains region of Gansu province, China, as our study area, and using the Sixth National Population Census alongside household survey data, we analyze changes in household livelihoods, and consequent regional effects, following the instigation of the “Grain for Green” program in 1999. Our results show rural livelihood changes with respect to natural assets (e.g., reduction of arable land, planting structure changes, human assets (e.g., labor quality improvement, fluidity of population, financial assets (e.g., income channels widening, income increasing, physical assets (e.g., optimized production tools, and social assets (e.g., information network development, increased outreach opportunities. We suggest that increased household livelihoods play an important role in improving land space utilization efficiency, resource conservation and use, and the ecological environment. However, owing to the natural environment, there are also some problems, such as “hollows” in rural production and living spaces, as well as local environmental degradation. To address these issues, regions such as the western, mountainous, impoverished area of our study should establish a policy of using ecosystems, as well as agriculture, for development in order to improve household livelihoods, build an efficient spatial structure, and providing support for the creation of a resource-saving societal system.

Effects of dripper discharge and irrigation frequency on growth and yield of maize in loess plateau of northwest china

International Nuclear Information System (INIS)

Xiukang, W.; Zhanbin, L.; Yingying, X.

2014-01-01

A field experiment was conducted at the Changwu Experimental Station in Changwu County, Shaanxi Province, in northwestern China from 2010 to 2011 with four treatments and six replicates in a randomized complete block design to determine appropriate dripper discharge and irrigation frequency for maize (Zea mays, L.) irrigated by drip irrigated system. Dripper discharge was applied to maize 1L/h of dripper discharge, 2 days irrigation frequency and 100% of evaporation from a class a pan (T1), 2, 3 and 4 L/h corresponding to 4, 6 and 8 days irrigation frequency, and deficit irrigation water levels was 90%, 80% and 70% of evaporation (T2, T3 and T4), respectively. The results indicated that longest root, root activity, plant height, leaf area, biomass and grain yields values were highest in T1 in both years. The highest grain yield was obtained of 8.78 and 8.84 t ha-1 under T1 in both years, and the minimum yield was obtained with 8.15 and 7.78 t ha-1 under T4 in 2010 and 2011, respectively. The maximum irrigation water use efficiency (IWUE) was 3.247 and 3.283 kg m-3 in both years under T4. Despite the reduction of growth and grain yield in T3, the dripper discharge was 3L/h, 6 days irrigation frequency and 80% of evaporation was still high and acceptable for maize production and irrigation water use efficiency in Loess Plateau of Northwest China. (author)

Species diversity, vegetation pattern and conservation of Gentiana macrophylla Pall. communities in Dongling mountain meadow, Beijing, China

International Nuclear Information System (INIS)

Sadia, S.; Zhang, J.T.; Bai, X.; Shedayi, A.A.; Tariq, A.

2017-01-01

Gentiana macrophylla, native to mountainous areas of Central and Southern Asia, is most popular remedy for rheumatism and pains in Traditional Chinese Medicine with an extensive demand in local market. Our study aimed to classify G. macrophylla communities and to find out the impact of topographic and soil factors on their diversity and distribution in Dongling mountain meadow, Beijing, China. Seventy five samples in 15 transects separated by 50m distance in altitude along an elevation gradient (1592-2298m) were established by quadrate method. TWINSAPN and CCA were used for classification and ordination, respectively. Six diversity indices (Species richness, Shannon-Weiner heterogeneity, Simpson’s index, Hill’s index, Pielou evenness and McIntosh evenness) were used to analyze the pattern of species diversity and polynomial regression analysis was used to establish their relationship with environmental variables. TWINSPAN classified G. macrophylla communities into 8 types and CCA indicated that soil pH, soil temperature, soil type, disturbance, total N, total K, Mg and Zn were significantly related to these communities. Elevation was the most significant factor that affecting the diversity and distribution of G. macrophylla communities. Significant effect of environment, topography and disturbance to meadow communities of G. macrophylla highly suggests some important measures such as uprooting restriction, tourism limitation in meadow area, monitoring of functional diversity, fertilization, irrigation, cloning and cultivation to protect and conserve it and its communities to be used in medicine industry. (author)

Temporal-Spatial Pattern of Carbon Stocks in Forest Ecosystems in Shaanxi, Northwest China.

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Gaoyang Cui

Full Text Available The precise and accurate quantitative evaluation of the temporal and spatial pattern of carbon (C storage in forest ecosystems is critical for understanding the role of forests in the global terrestrial C cycle and is essential for formulating forest management policies to combat climate change. In this study, we examined the C dynamics of forest ecosystems in Shaanxi, northwest China, based on four forest inventories (1989-1993, 1994-1998, 1999-2003, and 2004-2008 and field-sampling measurements (2012. The results indicate that the total C storage of forest ecosystems in Shaanxi increased by approximately 29.3%, from 611.72 Tg in 1993 to 790.75 Tg in 2008, partially as a result of ecological restoration projects. The spatial pattern of C storage in forest ecosystems mainly exhibited a latitude-zonal distribution across the province, increasing from north (high latitude to south (low latitude generally, which signifies the effect of environmental conditions, chiefly water and heat related factors, on forest growth and C sequestration. In addition, different data sources and estimation methods had a significant effect on the results obtained, with the C stocks in 2008 being considerably overestimated (864.55 Tg and slightly underestimated (778.07 Tg when measured using the mean C density method and integrated method, respectively. Overall, our results demonstrated that the forest ecosystem in Shaanxi acted as a C sink over the last few decades. However, further studies should be carried out with a focus on adaption of plants to environmental factors along with forest management for vegetation restoration to maximize the C sequestration potential and to better cope with climate change.

Cooling effect of agricultural irrigation over Xinjiang, Northwest China from 1959 to 2006

International Nuclear Information System (INIS)

Han Songjun; Yang Zhiyong

2013-01-01

The influences of agricultural irrigation on trends in surface air temperature from 1959 to 2006 over Xinjiang, Northwest China are evaluated using data from 90 meteorological stations. The 90 stations are located in landscapes with markedly different cultivated land uses. The increasing trends in daily average temperature (T a ), maximum temperature (T max ), and minimum temperature (T min ) for May–September (the main growing season) are negatively correlated with cultivated land proportions within 4 km of the meteorological stations, as indicated by year 2000 land use data. The correlations between the trends in T max and cultivated land proportions are the most significant. The trends in T a , T max , and T min for May–September are expected to decrease by −0.018, −0.014, and −0.016 ° C per decade, respectively, along with a 10% increase in cultivated land proportion. As irrigated cultivated land occupies over 90% of total cultivated land, the dependence of temperature trends on cultivated area is attributed to irrigation. The cooling effects on stations with cultivated land proportion larger than 50% are compared to temperature trends in a reference group with cultivated land proportion smaller than 10%. The irrigation expansion from 1959 to 2006 over Xinjiang is found to be associated with cooling of May–September T a , T max , and T min by around −0.15 ° C to −0.10 ° C/decade in the station group with extensive irrigation. Short periods of rapid irrigation expansion co-occurred with the significant cooling of the May–September temperature. (letter)

Multiple cooling episodes in the Central Tarim (Northwest China) revealed by apatite fission track analysis and vitrinite reflectance data

Science.gov (United States)

Chang, Jian; Qiu, Nansheng; Song, Xinying; Li, Huili

2016-06-01

Apatite fission track and vitrinite reflectance are integrated for the first time to study the cooling history in the Central Tarim, northwest China. The paleo-temperature profiles from vitrinite reflectance data of the Z1 and Z11 wells showed a linear relationship with depth, suggesting an approximately 24.8 °C/km paleo-geothermal gradient and 2700-3900 m of erosion during the Early Mesozoic. The measured apatite fission track ages from well Z2 in the Central Tarim range from 39 to 159 Ma and effectively record the Meso-Cenozoic cooling events that occurred in Central Tarim. Moreover, two cooling events at 190-140 Ma in the Early Jurassic-Early Cretaceous and 80-45 Ma in the Late Cretaceous-Paleocene revealed by measured AFT data and thermal modeling results are related to the collisions of the Qiangtang-Lhasa terranes and the Greater India Plate with the southern margin of the Eurasian Plate, respectively. This study provides new insights into the tectonic evolution of the Tarim Basin (and more broadly Central Asia) and for hydrocarbon generation and exploration in the Central Tarim.

LONG-TERM REMOTE MONITORING OF THREE TYPICAL LAKE AREA VARIATIONS IN THE NORTHWEST CHINA OVER THE PAST 40 YEARS

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Y. Liu

2018-04-01

Full Text Available water resources management and sustainable development strategy, but also provide reference for assessing the impact of climate change and human activities. This paper selects three inland lakes in Northwest China, using Landsat MSS/TM/ETM+/OLI data from 1970 to 2015, Normalized Difference Water Index (NDWI and Modified Normalized Difference Water Index (MNDWI were used to extract lake area and analysed the dynamic trends. Meteorological station rainfall, evaporation and other meteorological data of the lakes were used to analyse reasons for the area change. The results showed that area of Hongjiannao Lake in the past 40 a was reduced, the groundwater impoundment and underground coal mining are the main cause of area reduction; the area of Bosten Lake in recent 40 a showed a decreasing trend after the first increase, the area was mainly affected by the surface runoff and snowmelt; the area of Qinghai Lake in the past 40 a shows a trend of decreasing first and then increasing, the change of its area is mainly affected by regional precipitation and the inflow.

Long-Term Remote Monitoring of Three Typical Lake Area Variations in the Northwest China Over the Past 40 Years

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Liu, Y.; Lu, Y.; Li, Y.; Yue, H.

2018-04-01

water resources management and sustainable development strategy, but also provide reference for assessing the impact of climate change and human activities. This paper selects three inland lakes in Northwest China, using Landsat MSS/TM/ETM+/OLI data from 1970 to 2015, Normalized Difference Water Index (NDWI) and Modified Normalized Difference Water Index (MNDWI) were used to extract lake area and analysed the dynamic trends. Meteorological station rainfall, evaporation and other meteorological data of the lakes were used to analyse reasons for the area change. The results showed that area of Hongjiannao Lake in the past 40 a was reduced, the groundwater impoundment and underground coal mining are the main cause of area reduction; the area of Bosten Lake in recent 40 a showed a decreasing trend after the first increase, the area was mainly affected by the surface runoff and snowmelt; the area of Qinghai Lake in the past 40 a shows a trend of decreasing first and then increasing, the change of its area is mainly affected by regional precipitation and the inflow.

Viable contribution of Tibetan sacred mountains in southwestern China to forest conservation.

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Shen, Xiaoli; Li, Sheng; Wang, Dajun; Lu, Zhi

2015-12-01

The Tibetan sacred mountains (TSMs) cover a large area and may represent a landscape-scale conservation opportunity. We compared the conservation value of forests in these mountains with the conservation value of government-established nature reserves and unmanaged open-access areas in Danba County, southwestern China. We used Landsat satellite images to map forest cover and to estimate forest loss in 1974-1989, 1989-1999, and 1999-2013. The TSMs (n = 41) and nature reserves (n = 4) accounted for 21.6% and 29.7% of the county's land area, respectively. Remaining land was open-access areas (i.e., areas without any restrictions on resource use) (56.2%) and farmlands (2.2%). Within the elevation range suitable for forests, forest cover did not differ significantly between nature reserves (58.8%) and open-access areas (58.4%), but was significantly higher in TSMs (65.5%) after controlling for environmental factors such as aspect, slope, and elevation. The TSMs of great cultural importance had higher forest cover, but patrols by monastery staff were not necessarily associated with increased forest cover. The annual deforestation rate in nonsacred areas almost tripled in 1989-1999 (111.4 ha/year) relative to 1974-1989 (40.4 ha/year), whereas the rate in TSMs decreased in the later period (19.7 ha/year vs. 17.2 ha/year). The reduced forest loss in TSMs in 1989-1999 was possibly due to the renaissance of TSM worship and strengthened management by the local Buddhist community since late 1980s. The annual deforestation rate in Danba decreased dramatically to 4.4 ha/year in 1999-2013, which coincided with the implementation of a national ban on logging in 1998. As the only form of protected area across the Tibetan region during much of its history, TSMs have positively contributed to conserving forest at a landscape scale. Conservation of TSM forests largely relied on the strength of local religious institutions. Integrating community-based conservation of TSMs within the

Wind speed change regionalization in China (1961–2012

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Pei-Jun Shi

2015-06-01

Full Text Available This research quantitatively recognized the wind speed change using wind speed trend and trend of wind speed variability from 1961 to 2012 and regionalized the wind speed change on a county-level basis. The mean wind speed observation data and linear fitting method were used. The findings suggested that level-I regionalization includes six zones according to wind speed trend value in different regions, viz. Northeast China–North China substantial declining zone, East–Central China declining zone, Southeast China slightly declining zone, Southwest China very slightly declining zone, Northwest China declining zone, and Qinghai–Tibetan Plateau slightly declining zone. Level-II regionalization divides China into twelve regions based on trend of wind speed variability and the level-I regionalization results.

Natural radioactivity measurements in rock samples of Cuihua Mountain National Geological Park (China))

International Nuclear Information System (INIS)

Lu, X.; Zhang, X.

2008-01-01

The concentrations of the natural radionuclides namely 40 K, 232 Th and 226 Ra in rock samples collected from Cuihua Mountain National Geological Park of China have been determined using a NaI(Tl) detector. The concentrations of 226 Ra, 232 Th and 40 K in the studied rock samples range from 10.7 to 34.8, 19.9 to 53.6 and 642.7 to 1609.9 Bq kg -1 with an average of 20.4, 30.1 and 1009.5 Bq kg -1 , respectively. The concentrations of these radionuclides are compared with the typical world values. To evaluate the radiological hazard of the natural radioactivity, the radium equivalent activity, the air absorbed dose rate, the annual effective dose rate, the representative level index and the values of both external and internal hazard indices were evaluated and compared with the internationally approved values. The radium equivalent activity values of all rock samples are lower than the limit of 370 Bq kg -1 . The values of H ex and H in are less than unity. The mean outdoor air absorbed dose rate is 69.7 nGy h -1 , and the corresponding outdoor effective dose rate is 0.086 mSv y -1 . (authors)

Spatiotemporal variation of the surface water effect on the groundwater recharge in a low-precipitation region: Application of the multi-tracer approach to the Taihang Mountains, North China

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Sakakibara, Koichi; Tsujimura, Maki; Song, Xianfang; Zhang, Jie

2017-02-01

Groundwater recharge variations in time and space are crucial for effective water management, especially in low-precipitation regions. To determine comprehensive groundwater recharge processes in a catchment with large seasonal hydrological variations, intensive field surveys were conducted in the Wangkuai Reservoir watershed located in the Taihang Mountains, North China, during three different times of the year: beginning of the rainy season (June 2011), mid-rainy season (August 2012), and dry season (November 2012). Oxygen and hydrogen isotope and chemical analyses were conducted on the groundwater, spring water, stream water, and reservoir water of the Wangkuai Reservoir watershed. The results were processed using endmember mixing analysis to determine the amount of contribution of the groundwater recharging processes. Similar isotopic and chemical signatures between the surface water and groundwater in the target area indicate that the surface water in the mountain-plain transitional area and the Wangkuai Reservoir are the principal groundwater recharge sources, which result from the highly permeable geological structure of the target area and perennial large-scale surface water, respectively. Additionally, the widespread and significant effect of the diffuse groundwater recharge on the Wangkuai Reservoir was confirmed with the deuterium (d) excess indicator and the high contribution throughout the year, calculated using endmember mixing analysis. Conversely, the contribution of the stream water to the groundwater recharge in the mountain-plain transitional area clearly decreases from the beginning of the rainy season to the mid-rainy season, whereas that of the precipitation increases. This suggests that the main groundwater recharge source shifts from stream water to episodic/continuous heavy precipitation in the mid-rainy season. In other words, the surface water and precipitation commonly affect the groundwater recharge in the rainy season, whereas the

Plant invasions in mountains: Global lessons for better management

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McDougall, K.L.; Khuroo, A.A.; Loope, L.L.; Parks, C.G.; Pauchard, A.; Reshi, Z.A.; Rushworth, I.; Kueffer, C.

2011-01-01

Mountains are one of few ecosystems little affected by plant invasions. However, the threat of invasion is likely to increase because of climate change, greater anthropogenic land use, and continuing novel introductions. Preventive management, therefore, will be crucial but can be difficult to promote when more pressing problems are unresolved and predictions are uncertain. In this essay, we use management case studies from 7 mountain regions to identify common lessons for effective preventive action. The degree of plant invasion in mountains was variable in the 7 regions as was the response to invasion, which ranged from lack of awareness by land managers of the potential impact in Chile and Kashmir to well-organized programs of prevention and containment in the United States (Hawaii and the Pacific Northwest), including prevention at low altitude. In Australia, awareness of the threat grew only after disruptive invasions. In South Africa, the economic benefits of removing alien plants are well recognized and funded in the form of employment programs. In the European Alps, there is little need for active management because no invasive species pose an immediate threat. From these case studies, we identify lessons for management of plant invasions in mountain ecosystems: (i) prevention is especially important in mountains because of their rugged terrain, where invasions can quickly become unmanageable; (ii) networks at local to global levels can assist with awareness raising and better prioritization of management actions; (iii) the economic importance of management should be identified and articulated; (iv) public acceptance of management programs will make them more effective; and (v) climate change needs to be considered. We suggest that comparisons of local case studies, such as those we have presented, have a pivotal place in the proactive solution of global change issues. ?? International Mountain Society.

Impacts of Mining and Urbanization on the Qin-Ba Mountainous Environment, China

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Xinliang Xu

2016-05-01

Full Text Available The Qin-Ba Ecological Functional Zone is a component of China’s ecological security pattern designed to protect the regional ecosystem and maintain biodiversity. However, due to the impact of mining and urban encroachment, the plight of a sustainable ecosystem in the Qin-Ba mountainous area is deteriorating. This paper has used a remote sensing and geographic information system (GIS to examine the impacts of mining and urban encroachment on the environment in the Qin-Ba mountainous area. The results indicate that the total mined area in 2013 was 22 km2 and is predicted to escalate. Results also show that the ecosystems in Fengxian County, Shaanxi Province and Baokang County, Hubei Province were most severely affected by mining. Urbanization in the Qin-Ba mountainous area has seen an increase of 85.58 km2 in urban land use from 2010 to 2013. In addition, infrastructure development including airport construction, tourism resorts and real estate development in the Qin-Ba mountainous area has intensified environmental and biodiversity disturbances since large areas of forest have been cleared. Our results should provide insight and assistance to city planners and government officials in making informed decisions.

A synthesis of mineralization styles and geodynamic settings of the Paleozoic and Mesozoic metallic ore deposits in the Altay Mountains, NW China

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Yang, Fuquan; Geng, Xinxia; Wang, Rui; Zhang, Zhixin; Guo, Xuji

2018-06-01

The Altay Mountains within the Xinjiang region of northwestern China hosts major metallic ore deposits. Here we review the geological characteristics, metallogenic features and tectonic settings of these deposits. The metallic ore deposits in the Altay Mountains occur mainly within four regions: North Altay, Central Altay, South Altay and Erqis. We recognize seven types of metallic ore deposits in the Altay Mountains: VMS, submarine volcanogenic iron, magmatic, skarn, pegmatite, hydrothermal vein (Cu-Zn, Fe) and orogenic gold. Among these types, the VMS, pegmatite, orogenic gold and skarn deposits are the most common. Most of the rare metal pegmatite deposits are distributed in Central Altay, with only a few in South Altay. The VMS, submarine volcanogenic type iron and skarn-type deposits are distributed in South Altay, whereas the orogenic-type gold deposits are distributed in the Erqis Fault belt. The hydrothermal vein-type deposits occur in the Erqis Fault belt and Chonghu'er Basin in South Altay. Magmatic-type deposits are mostly in the Erqis Fault belt and Central Altay. Based on isotopic age data, the VMS, submarine volcanogenic-type Fe and skarn-type Cu, Pb, Zn, Fe mineralization occurred during Early-Middle Devonian (∼410-377 Ma), orogenic-type Au, magmatic-type Cu-Ni, and a small number of skarn-type Fe, hydrothermal vein-type Cu-Zn, pegmatite-type rare-metal deposits in Early-Middle Permian (293-261 Ma), pegmatite-type rare-metal deposits, few skarn-type Fe deposit in Early-Middle Triassic (248-232 Ma), and dominantly represented by pegmatite-type rare-metal deposits in Late Triassic-Early Jurassic (223-180 Ma). The metallic ore deposits in the Altay Mountains formed in various tectonic settings, such as the Early-Middle Devonian continental arc and oceanic island arc, Early-Middle Permian post-collisional extensional setting, and Triassic-Early Jurassic intracontinental setting.

Pattern and change of soil organic carbon storage in China: 1960s-1980s

International Nuclear Information System (INIS)

Shaoqiang Wang; Hanqin Tian; Jiyuan Liu; Shufen Pan

2003-01-01

Soils, an important component of the global carbon cycle, can be either net sources or net sinks of atmospheric carbon dioxide (CO 2 ). In this study, we use the first and second national soil surveys of China to investigate patterns and changes in soil organic carbon storage (SOC) during the period from the 1960s to the 1980s. Our results show that there is a large amount of variability in SOC density among different soil types and land uses in the 1980s. The SOC density in the wetlands of Southwest China was the highest (45 kg/m 2 ), followed by meadow soils in the South (26 kg/m 2 ), forest and woodlands in the Northwest (19 kg/m 2 ), steppe and grassland in the Northwest (15 kg/m 2 ), shrubs in the Northwest (12 kg/m 2 ), paddy lands in the Northwest (13 kg/m 2 ), and drylands in the Northwest (11 kg/m 2 ). The desert soils of the Western region ranked the lowest (1 kg/m 2 ). The density of SOC was generally higher in the west than other regions. Eastern China had the lowest SOC density, which was associated with a long history of extensive land use in the region. The estimation of SOC storage for the entire nation was 93 Pg C in the 1960s and 92 Pg C in the 1980s. SOC storage decreased about 1 Pg C during the 1960s-1980s. This amount of decrease in SOC for the entire nation is small and statistically insignificant. To adequately characterize spatial variations in SOC, larger sampling sizes of soil profiles will be required in the future analyses

Trekking through the ’Garden in the Clouds’ on Changbai Mountain

Institute of Scientific and Technical Information of China (English)

2005-01-01

<正>On the Changbai Mountain Nature Reserve (established in 1960) in Northeast China there lies some pure land unspoiled by human activity. This is an invaluable heritage left by our ancestors. Yet in our generation human interference is threatening its purity. When I climbed up the mountain in 1975 for the first time, I was fascinated by the profusion of flowers of all colours, luxuriant forests and large tracts of green meadows. From that moment on, these pictures were vividly engraved in my memory, and they often appear in my dreams. Now, almost twenty years have passed, in which mass tourism has been developing at a fast pace. Is my dream mountain still as charming as it was before? What

Hopes and challenges for giant panda conservation under climate change in the Qinling Mountains of China.

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Gong, Minghao; Guan, Tianpei; Hou, Meng; Liu, Gang; Zhou, Tianyuan

2017-01-01

One way that climate change will impact animal distributions is by altering habitat suitability and habitat fragmentation. Understanding the impacts of climate change on currently threatened species is of immediate importance because complex conservation planning will be required. Here, we mapped changes to the distribution, suitability, and fragmentation of giant panda habitat under climate change and quantified the direction and elevation of habitat shift and fragmentation patterns. These data were used to develop a series of new conservation strategies for the giant panda. Qinling Mountains, Shaanxi, China. Data from the most recent giant panda census, habitat factors, anthropogenic disturbance, climate variables, and climate predictions for the year 2050 (averaged across four general circulation models) were used to project giant panda habitat in Maxent. Differences in habitat patches were compared between now and 2050. While climate change will cause a 9.1% increase in suitable habitat and 9% reduction in subsuitable habitat by 2050, no significant net variation in the proportion of suitable and subsuitable habitat was found. However, a distinct climate change-induced habitat shift of 11 km eastward by 2050 is predicted firstly. Climate change will reduce the fragmentation of suitable habitat at high elevations and exacerbate the fragmentation of subsuitable habitat below 1,900 m above sea level. Reduced fragmentation at higher elevations and worsening fragmentation at lower elevations have the potential to cause overcrowding of giant pandas at higher altitudes, further exacerbating habitat shortage in the central Qinling Mountains. The habitat shift to the east due to climate change may provide new areas for giant pandas but poses severe challenges for future conservation.

Evaluation of body weight-based vancomycin therapy and the incidence of nephrotoxicity: a retrospective study in the northwest of China.

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Dong, Mo-Han; Wang, Jing-Wen; Wu, Yin; Chen, Bei-Yu; Yu, Min; Wen, Ai-Dong

2015-08-01

To identify specific risk factors of vancomycin-induced nephrotoxicity in China, as the relationship between vancomycin therapy (dosing and trough concentration monitoring) and nephrotoxicity has been the subject of critical debate. The cases of 90 critically ill patients who received vancomycin therapy in Xijing Hospital in the northwest of China between March 2014 and January 2015 were reviewed retrospectively. Vancomycin dosing, blood serum trough concentration, and other independent risk factors associated with nephrotoxicity were evaluated in a multivariable model. Among the 90 critically ill patients, 59 were males; mean age was 46.3 years. The indications for vancomycin use were methicillin-resistant Staphylococcus aureus-associated pneumonia, central nervous system infection, and bacteremia. Clinical pharmacists prescribed weight-based dosing, ranging from 20 to 45mg/kg/day. Fourteen (15.6%) patients developed nephrotoxicity, with serum creatinine elevated significantly from a mean (standard deviation) of 90.0 (18.8) μmol/l to 133.8 (63.2) μmol/l (p = 0.015). It was found that those with a vancomycin dosage >38mg/kg/day (50.0% vs. 11.3%, p = 0.004) and a vancomycin serum trough concentration >20mg/l (57.1% vs. 12.0%, p = 0.01) were more likely to develop nephrotoxicity. The data from this study indicate that a vancomycin dosage >38mg/kg/day and a serum trough level >20mg/l are both independent factors associated with the development of nephrotoxicity, suggesting that renal function should be monitored closely during vancomycin treatment. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Examining the impacts of disaster resettlement from a livelihood perspective: a case study of Qinling Mountains, China.

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Guo, Xuesong; Kapucu, Naim

2018-04-01

Disaster resettlement, as a mitigation and preparedness measure, entails significant economic, physical, and social impacts, which continue to challenge understanding of recovery from major events, especially regarding the extent of the context and environmental efforts to rebuild livelihoods. Based on a case study of Qinling Mountains, China, this research investigates the effects of disaster resettlement from a livelihoods perspective. Methodologically, it proposes a framework that combines the pressure-state-response framework and the sustainable livelihoods approach, and it employs a structural equation model to examine how specific factors affect disaster resettlement. The results indicate that conflicts may occur during and after resettlement owing to the difference or disparity between the concerns of resettled peasants and those of the government. Consequently, the risks related to livelihoods need to be taken seriously. Effective risk communication is critical to bridge the gap between different stakeholders. The paper concludes with some practical and policy recommendations. © 2018 The Author(s). Disasters © Overseas Development Institute, 2018.

Factors related to the distribution and prevalence of the fungal pathogen Batrachochytrium dentrobatidis in Rana cascadae and other amphibians in the Klamath Mountains

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Jonah Piovia-Scott; Karen L. Pope; Sharon P. Lawler; Esther M. Cole; Janet E. Foley

2011-01-01

The fungal pathogen Batrachochytrium dendrobatidis (Bd), which causes the disease chytridiomycosis, has been associated with declines and extinctions of montane amphibians worldwide. To gain insight into factors affecting its distribution and prevalence we focus on the amphibian community of the Klamath Mountains in northwest...

Post-Triassic thermal history of the Tazhong Uplift Zone in the Tarim Basin, Northwest China: Evidence from apatite fission-track thermochronology

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Caifu Xiang

2013-11-01

Full Text Available The Tarim Basin is a representative example of the basins developed in the northwest China that are characterized by multiple stages of heating and cooling. In order to better understand its complex thermal history, apatite fission track (AFT thermochronology was applied to borehole samples from the Tazhong Uplift Zone (TUZ. Twelve sedimentary samples of Silurian to Triassic depositional ages were analyzed from depths coinciding with the apatite partial annealing zone (∼60–120 °C. The AFT ages, ranging from 132 ± 7 Ma (from a Triassic sample to 25 ± 2 Ma (from a Carboniferous sample, are clearly younger than their depositional ages and demonstrate a total resetting of the AFT thermometer after deposition. The AFT ages vary among different tectonic belts and decrease from the No. Ten Faulted Zone (133–105 Ma in the northwest, the Central Horst Zone in the middle (108–37 Ma, to the East Buried Hill Zone in the south (51–25 Ma. Given the low magnitude of post-Triassic burial heating evidenced by low vitrinite reflectance values (Ro < 0.7%, the total resetting of the AFT system is speculated to result from the hot fluid flow along the faults. Thermal effects along the faults are well documented by younger AFT ages and unimodal single grain age distributions in the vicinity of the faults. Permian–early Triassic basaltic volcanism may be responsible for the early Triassic total annealing of those samples lacking connectivity with the fault. The above arguments are supported by thermal modeling results.

A decade of change in breastfeeding in China's far north-west

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Xiao Cuiqin

2006-11-01

Full Text Available Abstract Background There have been considerable changes in breastfeeding practices in China over the past forty years. However China is a very large country, and breastfeeding rates in different parts of China vary considerably. The objective of this paper is to identify and compare breastfeeding types and rates between 1994–1996 and 2003–2004 in Shihezi, Xinjiang Uygur Autonomous Region, PR China. Methods In 1994–1996, a study of breastfeeding (n = 2197 was undertaken in Shihezi, Xinjiang, PR China. A decade later in 2003–2004, a longitudinal study (n = 545 of infant feeding practices was undertaken in the same area. Results The 'any breastfeeding' rates at 1, 4 and 6 months were 94%, 82% and 78% respectively in the early 1990s. A decade later, breastfeeding at 1 month was lower, but rates at 4 and 6 months remained the same. In 2004 the 'full breastfeeding' rate at one month was significantly higher (57% than a decade earlier (38%, but after 3 months there was a rapid decline. This reflected a shift in the way complementary foods are introduced: the initial introduction was later, but by a higher proportion of mothers. Conclusion The rate of breastfeeding at one month is significantly lower in 2003–2004 when compared to 1994–1996. The 'full breastfeeding' rates were initially higher, but after 3 months were then lower. The Chinese national breastfeeding targets were not reached in either period of the study. These studies show the need to further promote full or exclusive breastfeeding and further longitudinal studies are necessary to provide the detailed knowledge about risk factors required for health promotion programs.

Habitat assessment for giant pandas in the Qinling Mountain region of China

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Feng, Tian-Tian; Van Manen, Frank T.; Zhao, Na-Xun; Li, Ming; Wei, Fu-Wen

2009-01-01

Because habitat loss and fragmentation threaten giant pandas (Ailuropoda melanoleuca), habitat protection and restoration are important conservation measures for this endangered species. However, distribution and value of potential habitat to giant pandas on a regional scale are not fully known. Therefore, we identified and ranked giant panda habitat in Foping Nature Reserve, Guanyinshan Nature Reserve, and adjacent areas in the Qinling Mountains of China. We used Mahalanobis distance and 11 digital habitat layers to develop a multivariate habitat signature associated with 247 surveyed giant panda locations, which we then applied to the study region. We identified approximately 128 km2 of giant panda habitat in Foping Nature Reserve (43.6% of the reserve) and 49 km2 in Guanyinshan Nature Reserve (33.6% of the reserve). We defined core habitat areas by incorporating a minimum patch-size criterion (5.5 km2) based on home-range size. Percentage of core habitat area was higher in Foping Nature Reserve (41.8% of the reserve) than Guanyinshan Nature Reserve (26.3% of the reserve). Within the larger analysis region, Foping Nature Reserve contained 32.7% of all core habitat areas we identified, indicating regional importance of the reserve. We observed a negative relationship between distribution of core areas and presence of roads and small villages. Protection of giant panda habitat at lower elevations and improvement of habitat linkages among core habitat areas are important in a regional approach to giant panda conservation.

Prevalence and associated factors of corneal blindness in Ningxia in northwest China

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Xun-Lun Sheng

2014-06-01

Full Text Available AIM:To describe the prevalence and demographic characteristics of corneal blindness in an urban and rural region of Ningxia, located in the northwest part of China.METHODS:A stratified, randomized sampling procedure was employed in the study, including urban and rural area of all age group. Visual acuity, anterior segment and ocular fundus were checked. Related factor of corneal disease, including age, gender, education status, ethnic group, location and occupation, were identified according to uniform customized protocol. An eye was defined to be corneal blindness if the visual acuity was <20/400 due to a corneal disease.RESULTS:Three thousand individuals (1290 from urban area and 1710 from rural area participated in the investigation, with a response rate of 80.380%. The prevalence of corneal blindness was 0.023% in both eyes and 0.733% in at least one eye. The blindness in at least one eye with varied causes was present in 106 participants (3.533% and in bilateral eyes in 34 participants (1.133%. The corneal diseases accounted for 20.754% of blindness in at least one eye and 20.588% of bilateral blindness. The prevalence of corneal disease was higher in older and Han ethnic group, especially those who occupied in agriculture and outdoor work. People with corneal blindness were more likely to be older and lower education. Rural population were more likely to suffer from bilateral corneal blindness than the urban population in ≥59-year group (χ2=6.716, P=0.019. Infectious, trauma and immune corneal disease were the three leading causes of corneal disease. Trauma corneal disease was more likely leading to blindness in one eye. However, infectious and immune corneal diseases make more contribution to the bilateral corneal blindness.CONCLUSION: Corneal blindness is a significant burden of in Ningxia population, encompassing a variety of corneal infections and trauma; the majority of those were avoidable. Health promotion strategies and good

Features and risk factors of nonfatal injury among the rural children: a survey of seven schools in a mountain area in Southwest China.

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Xiu-Quan Shi

Full Text Available We aimed to investigate the patterns and risk factors of nonfatal injuries among rural mountain-area children in southwest China.A stratified sampling method was used to recruit rural children aged 8 to 17 years (mainly 9-14 years from 7 schools. Self-reported injuries during the past 12 months and relevant concerns were collected from June to December 2012 by using a structured questionnaire in a class interview.The mean age of the 2,854 children was 12.2 ± 1.5 years. The probability of annual injury was 16.7% (95% confidence interval [95% CI] 15.3-18.1%, with slightly higher injury risk for boys than girls (17.7% vs. 16.0%; P>0.05. The top 3 causes of injuries were falls (37.3%, animal-related incidents (20.6%, and burns (14.9%. The main injury risk factors included being involved in a violent episode (odds ratio [OR] 1.34, 95% CI 1.08-1.66, P = 0.007, maltreatment by parents or guardians (1.42, 1.17-1.72, P<0.001, and being from a single-child family (1.30, 1.10-1.66, P = 0.039. Older age was a protective factor (0.81, 0.76-0.87, P<0.001.The incidence of nonfatal injury among rural children was high, and falls were the leading cause. Younger children and boys from poor-care and poor-living environments were at increased risk of injury, which requires urgent attention. Injury prevention programs targeting these issues are needed in this mountain area and similar rural regions of China.

International Briefing 29: Training and Development in Kazakhstan

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Mahmood, Monowar; Baimukhamedova, Aizhan

2013-01-01

The Republic of Kazakhstan is located in Central Asia, to the south of Russia and to the north-west of China. It occupies an area equal to 2724.9 thousand sq. km. and stretches east from the Caspian Sea and Volga plains to the Altai Mountains, from the foothills of Tien Shan in the south and southeast to the Western Siberian lowland in the north.…

Hot food and beverage consumption and the risk of esophageal squamous cell carcinoma: A case-control study in a northwest area in China.

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Tai, Wei-Ping; Nie, Guo-Ji; Chen, Meng-Jie; Yaz, Tajigul Yiminni; Guli, Arzi; Wuxur, Arzigul; Huang, Qing-Qing; Lin, Zhi-Gang; Wu, Jing

2017-12-01

This study was trying to investigate the association of hot food and beverage consumption and the risk of esophageal squamous cell carcinoma in Hotan, a northwest area of China with high risk of esophageal squmous cell carcinoma. A population-based case-control study was designed. For the study, 167 patients diagnosed with esophageal squamous cell carcinoma were selected from Hotan during 2014 to 2015, and 167 community-based controls were selected from the same area, matched with age and sex. Information involved of temperature of food and beverage intake was obtained by face-to-face interview. Logistic regression analyses were performed to investigate the association between temperature of food and beverage intake and the risk of esophageal squamous cell carcinoma. The temperature of the food and beverage consumed by the esophageal squamous cell carcinoma patients was significantly higher than the controls. High temperature of tea, water, and food intake significantly increased the risk of esophageal squamous cell carcinoma by more than 2-fold, with adjusted odds ratio 2.23 (1.45-2.90), 2.13 (1.53-2.66), and 2.98 (1.89-4.12). Intake of food and beverage with high temperature was positively associated with the incidence of esophageal squamous cell carcinoma in Northwestern China. Copyright © 2017 The Authors. Published by Wolters Kluwer Health, Inc. All rights reserved.

Glacial vicariance in the Pacific Northwest: evidence from a lodgepole pine mitochondrial DNA minisatellite for multiple genetically distinct and widely separated refugia.

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Godbout, Julie; Fazekas, Aron; Newton, Craig H; Yeh, Francis C; Bousquet, Jean

2008-05-01

The Canadian side of the Pacific Northwest was almost entirely covered by ice during the last glacial maximum, which has induced vicariance and genetic population structure for several plant and animal taxa. Lodgepole pine (Pinus contorta Dougl. ex. Loud.) has a wide latitudinal and longitudinal distribution in the Pacific Northwest. Our main objective was to identify relictual signatures of glacial vicariance in the population structure of the species and search for evidence of distinct glacial refugia in the Pacific Northwest. A maternally inherited mitochondrial DNA minisatellite-like marker was used to decipher haplotype diversity in 91 populations of lodgepole pine located across the natural range. Overall population differentiation was sizeable (G(ST) = 0.365 and R(ST) = 0.568). Four relatively homogeneous groups of populations, possibly representative of as many genetically distinct glacial populations, were identified for the two main subspecies, ssp. latifolia and ssp. contorta. For ssp. contorta, one glacial lineage is suggested to have been located at high latitudes and possibly off the coast of mainland British Columbia (BC), while the other is considered to have been located south of the ice sheet along the Pacific coast. For ssp. latifolia, two genetically distinct glacial populations probably occurred south of the ice sheet: in the area bounded by the Cascades and Rocky Mountains ranges, and on the eastern side of the Rockies. A possible fifth refugium located in the Yukon may have also been present for ssp. latifolia. Zones of contact between these ancestral lineages were also apparent in interior and northern BC. These results indicate the role of the Queen Charlotte Islands and the Alexander Archipelago as a refugial zone for some Pacific Northwest species and the vicariant role played by the Cascades and the American Rocky Mountains during glaciation.

Land tenure security and land investments in Northwest China

NARCIS (Netherlands)

Ma Xian lei, Xianlei; Heerink, N.; Ierland, van E.C.; Berg, van den M.; Shi, X.

2013-01-01

Purpose - The purpose of this paper is to examine the effect of perceived land tenure security in China on farmers' decisions to invest in relatively long-term land quality improvement measures, taking into account the potential endogeneity of tenure security. Design/methodology/approach – Data from

Distribution and Variability of Satellite-Derived Signals of Isolated Convection Initiation Events Over Central Eastern China

Science.gov (United States)

Huang, Yipeng; Meng, Zhiyong; Li, Jing; Li, Wanbiao; Bai, Lanqiang; Zhang, Murong; Wang, Xi

2017-11-01

This study combined measurements from the Chinese operational geostationary satellite Fengyun-2E (FY-2E) and ground-based weather radars to conduct a statistical survey of isolated convection initiation (CI) over central eastern China (CEC). The convective environment in CEC is modulated by the complex topography and monsoon climate. From May to August 2010, a total of 1,630 isolated CI signals were derived from FY-2E using a semiautomated method. The formation of these satellite-derived CI signals peaks in the early afternoon and occurs with high frequency in areas with remarkable terrain inhomogeneity (e.g., mountain, water, and mountain-water areas). The high signal frequency areas shift from northwest CEC (dry, high altitude) in early summer to southeast CEC (humid, low altitude) in midsummer along with an increasing monthly mean frequency. The satellite-derived CI signals tend to have longer lead times (the time difference between satellite-derived signal formation and radar-based CI) in the late morning and afternoon than in the early morning and night. During the early morning and night, the distinction between cloud top signatures and background terrestrial radiation becomes less apparent, resulting in delayed identification of the signals and thus short and even negative lead times. A decline in the lead time is observed from May to August, likely due to the increasing cloud growth rate and warm-rain processes. Results show increasing lead times with increasing landscape elevation, likely due to more warm-rain processes over the coastal sea and plain, along with a decreasing cloud growth rate from hill and mountain to the plateau.

Climate-driven speedup of alpine treeline forest growth in the Tianshan Mountains, Northwestern China.

Science.gov (United States)

Qi, Zhaohuan; Liu, Hongyan; Wu, Xiuchen; Hao, Qian

2015-02-01

Forest growth is sensitive to interannual climatic change in the alpine treeline ecotone (ATE). Whether the alpine treeline ecotone shares a similar pattern of forest growth with lower elevational closed forest belt (CFB) under changing climate remains unclear. Here, we reported an unprecedented acceleration of Picea schrenkiana forest growth since 1960s in the ATE of Tianshan Mountains, northwestern China by a stand-total sampling along six altitudinal transects with three plots in each transect: one from the ATE between the treeline and the forest line, and the other two from the CFB. All the sampled P. schrenkiana forest patches show a higher growth speed after 1960 and, comparatively, forest growth in the CFB has sped up much slower than that in the ATE. The speedup of forest growth at the ATE is mainly accounted for by climate factors, with increasing temperature suggested to be the primary driver. Stronger water deficit as well as more competition within the CFB might have restricted forest growth there more than that within the ATE, implying biotic factors were also significant for the accelerated forest growth in the ATE, which should be excluded from simulations and predictions of warming-induced treeline dynamics. © 2014 John Wiley & Sons Ltd.

Diurnal variation in soil respiration under different land uses on Taihang Mountain, North China

Science.gov (United States)

Liu, Xiuping; Zhang, Wanjun; Zhang, Bin; Yang, Qihong; Chang, Jianguo; Hou, Ke

2016-01-01

The aim of this paper is to evaluate the diurnal variation in soil respiration under different land use types on Taihang Mountain, North China, and to understand its response to environmental factors (e.g., soil temperature and moisture) and forest management. Diurnal variations in soil respiration from plantations (Robinia pseudoacacia, Punica granatum, and Ziziphus jujuba), naturally regenerated forests (Vitex negundo var. heterophylla), grasslands (Bothriochloa ischaemum), and farmlands (winter wheat/summer maize) were measured using an LI-8100 automated soil CO2 flux system from May 2012 to April 2013. The results indicated that land use type had a significant effect on the diurnal variation of soil respiration. The diurnal soil respiration from farmlands was highest, followed by Ziziphus jujube, R. pseudoacacia, P. granatum, the lower soil CO2 efflux was found from B. ischaemum and V. negundo var. heterophylla. The diurnal soil respiration across different land use types was significantly affected by soil temperature and moisture, and their interaction. Precipitation-stimulated soil respiration increased more in soil with low water content and less in soil with high water content. The lower diurnal soil respiration from naturally regenerated forests suggests that naturally regenerated vegetation is the optimal vegetation type for reducing global warming.

The Role of Biodiversity, Traditional Knowledge and Participatory Plant Breeding in Climate Change Adaptation in Karst Mountain Areas in SW China

Energy Technology Data Exchange (ETDEWEB)

Song, Yiching; Li, Jingsong [Center for Chinese Agricultural Policy (China)

2011-07-15

This is a report of a country case study on the impacts of climate change and local people's adaptation. The research sites are located in the karst mountainous region in 3 SW China provinces - Guangxi, Guizhou and Yunnan – an area inhabited by 33 ethnic groups of small farmers and the poor, with rich Plant Genetic Resources (PGR) and culture. Climate change is exacerbating already harsh natural conditions and impacting on biodiversity of remote farmers living in extreme poverty, with very limited arable land. Genetic diversity has also suffered from the adoption of high yielding hybrids. Yet traditional varieties, related TK and Participatory Plant Breeding (PPB) for maize and rice are showing real potential for resilience and adaptation.

Spatial and Decadal Variations in Potential Evapotranspiration of China Based on Reanalysis Datasets during 1982–2010

Directory of Open Access Journals (Sweden)

Yunjun Yao

2014-10-01

Full Text Available Potential evapotranspiration (PET is an important indicator of atmospheric evaporation demand and has been widely used to characterize hydrological change. However, sparse observations of pan evaporation (EP prohibit the accurate characterization of the spatial and temporal patterns of PET over large spatial scales. In this study, we have estimated PET of China using the Penman-Monteith (PM method driven by gridded reanalysis datasets to analyze the spatial and decadal variations of PET in China during 1982–2010. The results show that the estimated PET has decreased on average by 3.3 mm per year (p < 0.05 over China during 1982–1993, while PET began to increase since 1994 by 3.4 mm per year (p < 0.05. The spatial pattern of the linear trend in PET of China illustrates that a widely significant increasing trend in PET appears during 1982–2010 in Northwest China, Central China, Northeast China and South China while there are no obvious variations of PET in other regions. Our findings illustrate that incident solar radiation (Rs is the largest contributor to the variation of PET in China, followed by vapor pressure deficit (VPD, air temperature (Tair and wind speed (WS. However, WS is the primary factor controlling inter-annual variation of PET over Northwest China.

The Olympic Mountains Experiment for GPM (OLYMPEX)

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Houze, R.; McMurdie, L. A.; Petersen, W. A.; Schwaller, M.

2016-12-01

The GPM satellite has made it possible to observe the amount and nature of precipitation in remote areas of midlatitudes, including oceans and mountain ranges. OLYMPEX conducted over the Olympic Mountains on the northwest coast of Washington State was designed to provide the means for evaluating the physical basis of the algorithms used to convert GPM satellite measurements to determine the amount and nature of precipitation in midlatitude extratropical cyclones. Microphysical processes producing precipitation are highly sensitive to the vertical profile of temperature. In the tropics, the domain of the TRMM satellite, the temperature profile varies only slightly. GPM algorithms, however, must account for the strong horizontal variation of temperature profiles in baroclinic storms systems of midlatitudes and for the variations of precipitation mechanisms caused by passage of these storms over mountains. The OLYMPEX scientific strategy was: 1) collect a statistically robust set of measurements in midlatitude cyclones upstream of, over, and downstream of a midlatitude mountain range that can be used to improve GPM satellite algorithms; 2) determine how the physics and dynamics of the mechanisms affecting precipitation formation in relation to storm structure and terrain. To accomplish these goals 3 aircraft, 4 scanning dual polarization Doppler radars, supplemental soundings, and sophisticated surface instruments were deployed on the Olympic Peninsula of Washington, where Pacific frontal systems produce seasonal precipitation of 2000-4000 mm. 13 storms were observed. 3 of these were atmospheric rivers. The NASA DC-8 and ER-2 aircraft overflew the storms with instruments similar to those on GPM. The U. North Dakota Citation sampled hydrometeors in situ. Preliminary analysis indicates that one of the primary modes of orographic enhancement is low-level moist flow rising over the lower windward slopes and producing many very small drops. Ice-phase processes producing

Diversity and Spatial-Temporal Distribution of Soil Macrofauna Communities Along Elevation in the Changbai Mountain, China.

Science.gov (United States)

Yin, Xiuqin; Qiu, Lili; Jiang, Yunfeng; Wang, Yeqiao

2017-06-01

The understanding of patterns of vertical variation and diversity of flora and fauna along elevational change has been well established over the past century. However, it is unclear whether there is an elevational distribution pattern for soil fauna. This study revealed the diversity and spatial-temporal distribution of soil macrofauna communities in different vegetation zones from forest to alpine tundra along elevation of the Changbai Mountain, China. The abundance, richness, and Shannon-Wiener diversity index of soil macrofauna communities were compared in four distinguished vegetation zones including the coniferous and broadleaved mixed forest zone, the coniferous forest zone, the subalpine dwarf birch (Betula ermanii) forest zone, and the alpine tundra zone. Soil macrofauna were extracted in May, July, and September of 2009. In each season, the abundance and richness of the soil macrofauna decreased with the ascending elevation. The Shannon-Wiener diversity indices of the soil macrofauna were higher in the vegetation zones of lower elevation than of higher elevation. Significant differences were observed in the abundance, richness, and Shannon-Wiener diversity index for the studied vegetation zones. Soil macrofauna congregated mainly to the litter layer in the low-elevation areas and in the 0-5 cm soil layer of the higher elevation areas. The results emphasized that the diversity of soil macrofauna communities decreased as the elevation increased and possess the distinct characteristics of zonation in the mountain ecosystem. The diversity and distribution of soil macrofauna communities were influenced by mean annual precipitation, altitude, annual radiation quantity, and mean annual temperature. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Groundwater and surface-water interactions and impacts of human activities in the Hailiutu catchment, northwest China

Science.gov (United States)

Yang, Zhi; Zhou, Yangxiao; Wenninger, Jochen; Uhlenbrook, Stefan; Wang, Xusheng; Wan, Li

2017-08-01

The interactions between groundwater and surface water have been significantly affected by human activities in the semi-arid Hailiutu catchment, northwest China. Several methods were used to investigate the spatial and temporal interactions between groundwater and surface water. Isotopic and chemical analyses of water samples determined that groundwater discharges to the Hailiutu River, and mass balance equations were employed to estimate groundwater seepage rates along the river using chemical profiles. The hydrograph separation method was used to estimate temporal variations of groundwater discharges to the river. A numerical groundwater model was constructed to simulate groundwater discharges along the river and to analyze effects of water use in the catchment. The simulated seepage rates along the river compare reasonably well with the seepage estimates derived from a chemical profile in 2012. The impacts of human activities (river-water diversion and groundwater abstraction) on the river discharge were analyzed by calculating the differences between the simulated natural groundwater discharge and the measured river discharge. Water use associated with the Hailiutu River increased from 1986 to 1991, reached its highest level from 1992 to 2000, and decreased from 2001 onwards. The reduction of river discharge might have negative impacts on the riparian ecosystem and the water availability for downstream users. The interactions between groundwater and surface water as well as the consequences of human activities should be taken into account when implementing sustainable water resources management in the Hailiutu catchment.

Observation of water and heat fluxes in the Badain Jaran desert, China

NARCIS (Netherlands)

Zhang, T.; Wen, J.; Su, Z.; Tian, H.; Zeng, Y.

Badain Jaran Desert lie in the northwest of the Alashan plateau in western Inner Mongolia of China, between39o20'N to 41o30'N and 100oE to 104oE. It is the 4th largest desert in the world and the second largest desert in China, with an area of 49000 square kilometers and an altitude between 900 and

Glacier change in the Gangdise Mountains, southern Tibet, since the Little Ice Age

Science.gov (United States)

Zhang, Qian; Yi, Chaolu; Fu, Ping; Wu, Yubin; Liu, Jinhua; Wang, Ninglian

2018-04-01

Delineating glacier change during the Little Ice Age (LIA) is of great importance when attempting to understand regional climatic changes and can also help to improve the understanding of any predictions of future glacial changes. However, such knowledge is still lacking for some critical regions of the Tibetan Plateau (TP). In this study, we mapped 4188 contemporary glaciers and reconstructed 1216 LIA areas of glacial coverage in the Gangdise Mountains to the north of the Himalaya using Google Earth satellite imagery. We estimated their paleoglacial areas and equilibrium line altitudes (ELAs) based on the toe-to-headwall altitude ratio (THAR) method. Results show that most glaciers are small (ELA ranges from 5516 to 6337 m asl; the LIA ELA ranged from 5476 to 6329 m asl. Contemporary and LIA ELA values rise from southeast to northwest. As a general rule, the rise in the ELA value decreases from the eastern to the central Gangdise Mountains and then increases westward, with a mean ELA rise of 45 m. Multiple regression models suggest that 46.8% of the glacier area loss can be explained by glacier elevation, area, and slope. However, only 15.5% of the rise in ELA values can be explained by glacial geometric, topographic, or locational parameters. The spatial pattern of modern ELA values in this region appears inversely related to precipitation, which decreases from southeast to northwest, implying that precipitation is one of the key controls of ELAs. This is also consistent with results from elsewhere in High Asia. In contrast to the Gangdise Mountains' eastern and western sectors, glaciers in the central sector have undergone less change, i.e., in terms of reductions in length, area loss, and rises in ELA. Topography can of course also influence glacial change by creating shielding and/or rainshadow effects and by affecting local temperatures.

A closer looking at dimming and brightening in China during 1961-2005

Energy Technology Data Exchange (ETDEWEB)

Xia, X. [Chinese Academy of Sciences, Beijing (China). LAGEO, Inst. of Atmospheric Physics

2010-07-01

This study investigates dimming and brightening of surface solar radiation (SSR) during 1961-2005 in China as well as its relationships to total cloud cover (TCC). This is inferred from daily ground-based observational records at 45 pyranometer stations. A statistical method is introduced to study contributions of changes in the frequency of TCC categories and their atmospheric transparency to the secular SSR trend. The surface records suggest a renewed dimming beyond 2000 in North China after the stabilization in the 1990s; however, a slight brightening appears beyond 2000 in South China. Inter-annual variability of SSR is negatively correlated with that of TCC, but there is a positive correlation between decadal variability of SSR and TCC in most cases. The dimming during 1961-1990 is exclusively attributable to decreased atmospheric transparency, a portion of which is offset by TCC frequency changes in Northeast and Southwest China. The dimming during 1961-1990 in Northwest and Southeast China primarily results from decreased atmospheric transparency under all sky conditions and the percentage of dimming stemming from TCC frequency changes is 11% in Northwest and 2% in Southeast China. Decreased atmospheric transparencies during 1991- 2005 in North China in most cases lead to the dimming. TCC frequency changes also contribute to the dimming during this period in North China. This feature is more pronounced in summer and winter when TCC frequency changes can account for more than 80% of dimming. In South China, increased atmospheric transparencies lead to the brightening during 1991-2005. A substantial contribution by TCC frequency changes to the brightening is also evident in spring and autumn. (orig.)

Methane-metabolizing microbial communities in sediments of the Haima cold seep area, northwest slope of the South China Sea.

Science.gov (United States)

Niu, Mingyang; Fan, Xibei; Zhuang, Guangchao; Liang, Qianyong; Wang, Fengping

2017-09-01

Cold seeps are widespread chemosynthetic ecosystems in the deep-sea environment, and cold seep microbial communities of the South China Sea are poorly constrained. Here we report on the archaeal communities, particularly those involved in methane metabolization, in sediments of a newly discovered cold seep (named 'Haima') on the northwest slope of the South China Sea. Archaeal diversity, abundance and distribution were investigated in two piston cores collected from a seep area (QDN-14B) and a non-seep control site (QDN-31B). Geochemical investigation of the QDN-14B core identified an estimated sulfate-methane transition zone (Estimated SMTZ) at 300-400 cm below sea floor (cmbsf), where a high abundance of anaerobic methane-oxidizing archaea (ANME) occurred, as revealed by analysis of the 16S rRNA gene and the gene (mcrA) encoding the α-subunit of the key enzyme methyl-coenzyme M reductase. ANME-2a/b was predominant in the upper and middle layers of the estimated SMTZ, whereas ANME-1b outcompeted ANME-2 in the sulfate-depleted bottom layers of the estimated SMTZ and the methanogenic zone. Fine-scale phylogenetic analysis further divided the ANME-1b group into three subgroups with different distribution patterns: ANME-1bI, ANME-1bII and ANME-1bIII. Multivariate analyses indicated that dissolved inorganic carbon and sulfate may be important factors controlling the composition of the methane-metabolizing community. Our study on ANME niche separation and interactions with other archaeal groups improves our understanding of the metabolic diversity and flexibility of ANME, and the findings further suggest that ANME subgroups may have evolved diversified/specified metabolic capabilities other than syntrophic anaerobic oxidation of methane coupled with sulfate reduction in marine sediments. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

[Source identification and potential ecological hazards assessment of trace metalloid/heavy metals in the soil of Tianshan Mountains, Xinjiang, China].

Science.gov (United States)

Zhang, Zhao-Yong; Jilili, Abuduwailil; Jiang, Feng-Qing

2014-11-01

In this study, the contents of ten metalloid/heavy metals (As, Pb, Ni, Cd, Co, Hg, Cu, Mn, Zn and Cr) in soil samples collected from three sections including the central Urumqi-Akesu, eastern Blikun-Yiwu and western Zhaosu-Tekesi in Tianshan Mountains were determined, and their sources were identified by using typical statistical and multivariate statistical methods. The potential ecological risks of these heavy metals were assessed by employing pollution index method, potential ecological risk index and the background values of Tianshan Mountains, and Xinjiang, and also the Second National Standard of the Soil Qualities of China. The results showed that the contents of the heavy metals (Pb, Ni, Cd, Co, Hg, Cu, Mn Zn and Cr) and metalloid As were all higher than the soil background values of the Tianshan Mountain or Xinjiang, and their variation co- efficients belonged to the medium variation. In general, the contents of the ten metalloid/heavy metals in the soil of Tianshan Mountains were low. Principal component analysis showed that the ten metalloid/heavy metals could be identified as two principal components, among which PC1 (Cd, Pb, Hg, Mn and Zn) could be seen as 'human influence sources factor', PC2 (Cu, Ni, Cr, Co and As) as 'natural sources factor'. Mn and As had larger loads both in PC1 and PC2, and they could be co-influenced by human and natural sources. The pollution assessment showed that Hg and Cd in central Urumuqi-Akesu section and As in western Zhaosu-Tekesi section were all at alert level, while the other heavy metals in other sections were all at security level. From the comprehensive pollution indices (P(z)) of heavy metals, it was found that the ten metalloid/heavy metals in the soils of central Urumqi-Akesu section were at low pollution level, but those in the other two sections were at clean level. The potential ecological risk assessment showed that the potential ecological risk coefficient (E(i)r) and the ecological damage index (RI) of Hg

Mental health and burnout in primary and secondary school teachers in the remote mountain areas of Guangdong Province in the People's Republic of China

Directory of Open Access Journals (Sweden)

Zhang L

2014-01-01

Full Text Available Lulu Zhang,1 Jingping Zhao,1 Huaqing Xiao,3 Hongbo Zheng,2 Yaonan Xiao,3 Miaoyang Chen,3 Dingling Chen31Mental Health Institute of the Second Xiangya Hospital, Key Laboratory of Psychiatry and Mental Health of Hunan Province, Central South University, Changsha, Hunan, 2Department of Psychiatry, Guangzhou Brain Hospital, Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, 3Department of Psychiatry, Luoding Dagang Hospital, Luoding, Guangdong, People's Republic of ChinaBackground: A growing number of studies have shown that education is a work context in which professionals (teachers seem likely to suffer from burnout that may be associated with low levels of mental health. Although there is a demonstrated need to improve the mental health and burnout levels among teachers, little is known about their mental health status, particularly with respect to graduating class teachers in remote mountain areas with undeveloped economies. The purpose of this study was to survey mental health and burnout among graduating class teachers in remote mountain areas and to examine the influence of moderating variables.Methods: We conducted a multilevel analysis of 590 graduating class teachers from 42 primary and secondary schools in remote mountain areas of Guangdong province in the People's Republic of China. The outcome variable of self-reported mental health was measured by the Symptom Checklist-90 (SCL-90, and burnout was measured by the Chinese Maslach Burnout Inventory for primary and secondary school teachers.Results: The status of both mental health and burnout among the respondents was significantly more troubling than the national norm used as a reference (P<0.05 or P<0.01. Each factor in the SCL-90 had a significant correlation with burnout (P<0.01. All factors of the SCL-90 were entered into the regression equation for each dimension of burnout (P<0.01. The factor having the greatest impact on emotional exhaustion and

Trends and sensitivities of low streamflow extremes to discharge timing and magnitude in Pacific Northwest mountain streams

Science.gov (United States)

Patrick R. Kormos; Charlie Luce; Seth J. Wenger; Wouter R. Berghuijs

2016-01-01

Path analyses of historical streamflow data from the Pacific Northwest indicate that the precipitation amount has been the dominant control on the magnitude of low streamflow extremes compared to the air temperature-affected timing of snowmelt runoff. The relative sensitivities of low streamflow to precipitation and temperature changes have important...

Land tenure in China: Legal, actual and perceived security

NARCIS (Netherlands)

Ma, Xianlei; Heerink, N.; Feng, S.; Shi, X.

2015-01-01

This paper examines the magnitudes of legal security, actual security and perceived security of farmland tenure, and the causes of currently prevailing land tenure insecurity in rural China. Two farm household surveys conducted in the northwest of Gansu province in 2010 and in the northeast of

Timing and Spatial Distribution of Loess in Xinjiang, NW China.

Directory of Open Access Journals (Sweden)

Yun Li

Full Text Available Central Asia is one of the most significant loess regions on Earth, with an important role in understanding Quaternary climate and environmental change. However, in contrast to the widely investigated loess deposits in the Chinese Loess Plateau, the Central Asian loess-paleosol sequences are still insufficiently known and poorly understood. Through field investigation and review of the previous literature, the authors have investigated the distribution, thickness and age of the Xinjiang loess, and analyzed factors that control these parameters in the Xinjiang in northwest China, Central Asia. The loess sediments cover river terraces, low uplands, the margins of deserts and the slopes of the Tianshan Mountains and Kunlun Mountains and are also present in the Ili Basin. The thickness of the Xinjiang loess deposits varies from several meters to 670 m. The variation trend of the sand fraction (>63 μm grain-size contour can indicate the local major wind directions, so we conclude that the NW and NE winds are the main wind directions in the North and South Xinjiang, and the westerly wind mainly transport dust into the Ili basin. We consider persistent drying, adequate regional wind energy and well-developed river terraces to be the main factors controlling the distribution, thickness and formation age of the Xinjiang loess. The well-outcropped loess sections have mainly developed since the middle Pleistocene in Xinjiang, reflecting the appearance of the persistent drying and the present air circulation system. However, the oldest loess deposits are as old as the beginning of the Pliocene in the Tarim Basin, which suggests that earlier aridification occurred in the Tarim Basin rather than in the Ili Basin and the Junggar Basin.

Assessment of diabetes care and the healthcare system in economically and transport underdeveloped rural mountain areas of western China: A cross-sectional survey.

Science.gov (United States)

Ke, Linqiu; Zhang, Yuwei; Wang, Xiaoqian; Li, Shengyong; Yang, Wei; Tong, Nanwei

2017-05-01

The aim of the present study was to assess the quality of diabetes care and characteristics of the healthcare system in underdeveloped rural mountain areas of western China. Questionnaires were used to collect data from 288 diabetic patients with a multistage cluster sampling method in Zhongjiang County (Sichuan Province) between October 2009 and April 2010. Sixty-two village clinics, 23 town health centers, and a county central hospital were included to assess the availability of diabetes-related medical resources, in addition to diabetes-related medical insurance, reimbursement policies, and manpower. Of 288 patients, 38.2 % monitored their blood glucose regularly. Targets for fasting blood glucose (≤7 mmol/L) and blood pressure (≤130/80 mmHg) were achieved by 7.6 % and 9.7 % of patients, respectively. On average, each patient paid US$120 out of pocket annually for out-patient diabetes care, with a maximum US$86 reimbursed. The county central hospital was the only healthcare facility in the county that could provide all essential diabetes-related drugs and process-of-care measures and tests, except measures of HbA1c and the urinary albumin: creatinine ratio. Insulin was not available at village clinics, and only 29 % of village clinics had glucometers. "Certified" doctors were not available to provide primary care in village clinics. The quality of diabetes care was quite poor in underdeveloped rural mountain areas of western China. Recommendations for further intervention research to improve diabetes healthcare include increasing investment in medical infrastructure, improving the availability of essential drugs and process measures, organizing regular diabetes patient education, and recruiting village doctors. © 2016 Ruijin Hospital, Shanghai Jiaotong University School of Medicine and John Wiley & Sons Australia, Ltd.

The tectonic and stratigraphic history of the Cardaño area, Cantabrian mountains, Northwest Spain

NARCIS (Netherlands)

Veen, van J.

1965-01-01

The Devonian and Carboniferous rock-sequence in the Cantabrian Mountains is developed in two different facies which are separated by an E-W tectonic line, the León Line, and called the Leonide and Palentian facies, respectively to the S and N. The Leonide facies is widely exposed throughout the

Observed and Projected Changes in Thermal Growing Degree-Days and Growing Season and Their Divergent Responses to Warming over China

Science.gov (United States)

Deng, H.

2017-12-01

Vegetation growth and phenology are largely regulated by the growing degree-days (GDD) and growing season (GS). By choosing 0°C, 5°C and 10°C, three key based temperatures (Tb) for vegetation growth, the GDD and GS in China during the observed period (1960-2011) were developed using homogenized daily mean temperatures (Td) in 536 meteorological stations. In addition, the GDD10 and GS10 in China were projected under the representative concentration pathway scenarios (RCPs) during 1961-2099, using the Td (0.5°×0.5°) derived from five general circulation models (GCMs), after model evaluation. Advance in the start of the growing season (SOS; 4.86-6.71 days; SOS0 > SOS5 > SOS10) and delay in the end of the growing season (EOS; 4.32-6.19 days; EOS0 GDD5 > GDD10), in China as a whole. Each observed variation has a substantial acceleration mostly in 1987 or 1996, and a speed reduction or a trend reversal in the early 2000s. Increases in the GDD10 and GS10 would continue in the 21st century, causing northward shifts in the temperature zones. Finally in the long-term (2071-2099), the nationally average GDD10 and GS10 would be 279.1°C·d higher and 16.5 d longer for RCP 2.6, and 964.4°C·d higher and 50.3 d longer for RCP 8.5, relative to 1981-2010. Regionally, the GDD enhancement were stronger in the tropics, east, northeast and northwest China during the observed period, and tend to be in southern China in the future. The largest GS extensions are consistently in the eastern and southern parts of the Tibetan Alpine zone, particularly in the future. During the observed period, advance in SOS and delay in EOS drove the GS extensions in the eastern monsoon zone and northwest arid/semi-arid zone respectively. In the future, an advanced SOS drives the GS extension in the northern (> ca. 33°N) Tibetan Alpine zone, the mountainous areas in northeast China, and south of the Tropic of Cancer. The GDD and GS showed positive sensitivity to the temperature (GDD0 > GDD5 > GDD10

Does migration benefit the schooling of children left behind?: Evidence from rural northwest China

Directory of Open Access Journals (Sweden)

Feng Hu

2013-07-01

Full Text Available BACKGROUND While many studies have found that migration can benefit home communities and family members left behind by increasing household income, thus easing liquidity constraints on investment; less is known about how "internal" migration and remittances affect the educational performance of the children who are left behind in the source communities. OBJECTIVE My aim in this paper is to examine the effects of migration on the educational attainment of left-behind rural children in northwest China. To gain a better understanding of whether the educational performance of these children improves or suffers when adult family members migrate, I attempt to disentangle the effects of remittances from the effects of migration. METHODS The data used in this study come from the 2004 wave of the Gansu Survey of Children and Families. To account for the possible endogeneity of migration-related variables, I use the migration network variables to instrument for different migration strategies. RESULTS The results show that the absence of adult household members, including parents, has a negative effect on the educational performance of the children left behind, but that remittances can partially compensate for this loss. Boys' educational performance does not seem to be greatly affected by the migration of adult household members. By contrast, the absence of adult household members is shown to have a large negative effect on girls' educational performance, and the positive effect of remittances is also found to be significant for girls. CONCLUSIONS The findings may be of interest to other developing countries with large internal migration flows and to the relevant policy makers, as the results suggest that remittances sent home by out-migrants may serve as a channel for investing in human capital in the migrants' regions of origin, and especially for investing in the human capital of girls.

A tunnel runs through it: an inside view of the Tualatin Mountains, Oregon

Science.gov (United States)

Walsh, Ken; Peterson, Gary L.; Beeson, Marvin H.; Wells, Ray E.; Fleck, Robert J.; Evarts, Russell C.; Duvall, Alison; Blakely, Richard J.; Burns, Scott

2011-01-01

The Tualatin Mountains form a northwest-striking ridge about 350 m high that separates Portland, Oregon, from the cities of the Tualatin Valley to the west. Known informally as the Portland Hills, the ridge is a late Cenozoic anticline, bounded by reverse faults that dip toward the anticlinal axis. The anticline is a broad, open fold consisting chiefly of Miocene Columbia River Basalt Group, with remnants of Miocene-Pliocene Troutdale Formation and Pleistocene basalt of the Boring Volcanic Field on the flanks of the anticline. Anticlinal structures similar to the Tualatin Mountains are characteristic of the northern Willamette Valley, where the structures accommodate margin-parallel shortening of the Cascadia fore arc. Global Positioning System (GPS) results indicate that the shortening is due to the northward motion of Oregon at several millimeters per year with respect to stable North America. Some of the uplifts may contain active faults, but the structures are poorly exposed and are overlain by thick Pleistocene loess and Missoula flood deposits. Between 1993 and 1998, construction of the 3-mile-long (4500-m-long) TriMet MAX Light Rail tunnel through the Tualatin Mountains provided an unusual opportunity to investigate the geological structure and history of the Tualatin Mountains. This report is a collaborative effort among the tunnel geologists and the U.S. Geological Survey (USGS) to document the geologic story and quantify late Cenozoic and Quaternary deformation rates of the Tualatin Mountains.

Stair-Step Pattern of Soil Bacterial Diversity Mainly Driven by pH and Vegetation Types Along the Elevational Gradients of Gongga Mountain, China.

Science.gov (United States)

Li, Jiabao; Shen, Zehao; Li, Chaonan; Kou, Yongping; Wang, Yansu; Tu, Bo; Zhang, Shiheng; Li, Xiangzhen

2018-01-01

Ecological understandings of soil bacterial community succession and assembly mechanism along elevational gradients in mountains remain not well understood. Here, by employing the high-throughput sequencing technique, we systematically examined soil bacterial diversity patterns, the driving factors, and community assembly mechanisms along the elevational gradients of 1800-4100 m on Gongga Mountain in China. Soil bacterial diversity showed an extraordinary stair-step pattern along the elevational gradients. There was an abrupt decrease of bacterial diversity between 2600 and 2800 m, while no significant change at either lower (1800-2600 m) or higher (2800-4100 m) elevations, which coincided with the variation in soil pH. In addition, the community structure differed significantly between the lower and higher elevations, which could be primarily attributed to shifts in soil pH and vegetation types. Although there was no direct effect of MAP and MAT on bacterial community structure, our partial least squares path modeling analysis indicated that bacterial communities were indirectly influenced by climate via the effect on vegetation and the derived effect on soil properties. As for bacterial community assembly mechanisms, the null model analysis suggested that environmental filtering played an overwhelming role in the assembly of bacterial communities in this region. In addition, variation partition analysis indicated that, at lower elevations, environmental attributes explained much larger fraction of the β-deviation than spatial attributes, while spatial attributes increased their contributions at higher elevations. Our results highlight the importance of environmental filtering, as well as elevation-related spatial attributes in structuring soil bacterial communities in mountain ecosystems.

Effect of Aspect on Climate Variation in Mountain Ranges of Shen-nongjia Massif, Central China

Institute of Scientific and Technical Information of China (English)

ZHANG Yi

2018-01-01

The aim of this study was to better understand the mechanisms of regional climate variation in mountain ranges with con-trasting aspects as mediated by changes in global climate. It may help predict trends of vegetation variations in native ecosystems in natural reserves. As measures of climate response, temperature and precipitation data from the north, east, and south-facing mountain ranges of Shennongjia Massif in the coldest and hottest months (January and July), different seasons (spring, summer, autumn, and win-ter) and each year were analyzed from a long-term dataset (1960 to 2003) to tested variations characteristics, temporal and spatial quan-titative relationships of climates. The results showed that the average seasonal temperatures and precipitation in the north, east, and south aspects of the mountain ranges changed at different rates. The average seasonal temperatures change rate ranges in the north, east, and south-facing mountain ranges were from –0.0210℃ /yr to 0.0143℃ /yr,–0.0166℃ /yr to 0.0311℃ /yr, and –0.0290℃ /yr to 0.0084℃ /yr, respectively,and seasonal precipitation variation magnitude were from –1.4940 mm/yr to 0.6217 mm/yr, –1.6833 mm/yr to 2.6182 mm/yr, and –0.8567 mm/yr to 1.4077 mm/yr, respectively. The climates variation trend among the three mountain ranges were different in magnitude and direction, showing a complicated change of the climates in mountain ranges and some inconsistency with general trends in global climate change. The climate variations were significantly different and positively correlated cross mountain ranges, revealing that aspects significantly affected on climate variations and these variations resulted from a larger air circulation sys-tem, which were sensitive to global climate change. We conclude that location and terrain of aspect are the main factors affecting dif-ferences in climate variation among the mountain ranges with contrasting aspects.

Land tenure insecurity and rural-urban migration in rural China

NARCIS (Netherlands)

Ma Xian lei, Xianlei; Heerink, N.B.M.; Ierland, van E.C.; Shi Xiaoping, X.

2016-01-01

This paper examines the impact of land tenure security perceptions on rural-urban migration decisions of rural households, using data collected in Minle County in Northwest China. We find that tenure security perceptions play a significant role in household migration decisions in villages without

Regional air-sea coupled model simulation for two types of extreme heat in North China

Science.gov (United States)

Li, Donghuan; Zou, Liwei; Zhou, Tianjun

2018-03-01

Extreme heat (EH) over North China (NC) is affected by both large scale circulations and local topography, and could be categorized into foehn favorable and no-foehn types. In this study, the performance of a regional coupled model in simulating EH over NC was examined. The effects of regional air-sea coupling were also investigated by comparing the results with the corresponding atmosphere-alone regional model. On foehn favorable (no-foehn) EH days, a barotropic cyclonic (anticyclonic) anomaly is located to the northeast (northwest) of NC, while anomalous northwesterlies (southeasterlies) prevail over NC in the lower troposphere. In the uncoupled simulation, barotropic anticyclonic bias occurs over China on both foehn favorable and no-foehn EH days, and the northwesterlies in the lower troposphere on foehn favorable EH days are not obvious. These biases are significantly reduced in the regional coupled simulation, especially on foehn favorable EH days with wind anomalies skill scores improving from 0.38 to 0.47, 0.47 to 0.61 and 0.38 to 0.56 for horizontal winds at 250, 500 and 850 hPa, respectively. Compared with the uncoupled simulation, the reproduction of the longitudinal position of Northwest Pacific subtropical high (NPSH) and the spatial pattern of the low-level monsoon flow over East Asia are improved in the coupled simulation. Therefore, the anticyclonic bias over China is obviously reduced, and the proportion of EH days characterized by anticyclonic anomaly is more appropriate. The improvements in the regional coupled model indicate that it is a promising choice for the future projection of EH over NC.

A closer looking at dimming and brightening in China during 1961–2005

Directory of Open Access Journals (Sweden)

X. Xia

2010-05-01

Full Text Available This study investigates dimming and brightening of surface solar radiation (SSR during 1961–2005 in China as well as its relationships to total cloud cover (TCC. This is inferred from daily ground-based observational records at 45 pyranometer stations. A statistical method is introduced to study contributions of changes in the frequency of TCC categories and their atmospheric transparency to the secular SSR trend. The surface records suggest a renewed dimming beyond 2000 in North China after the stabilization in the 1990s; however, a slight brightening appears beyond 2000 in South China. Inter-annual variability of SSR is negatively correlated with that of TCC, but there is a positive correlation between decadal variability of SSR and TCC in most cases. The dimming during 1961–1990 is exclusively attributable to decreased atmospheric transparency, a portion of which is offset by TCC frequency changes in Northeast and Southwest China. The dimming during 1961–1990 in Northwest and Southeast China primarily results from decreased atmospheric transparency under all sky conditions and the percentage of dimming stemming from TCC frequency changes is 11% in Northwest and 2% in Southeast China. Decreased atmospheric transparencies during 1991–2005 in North China in most cases lead to the dimming. TCC frequency changes also contribute to the dimming during this period in North China. This feature is more pronounced in summer and winter when TCC frequency changes can account for more than 80% of dimming. In South China, increased atmospheric transparencies lead to the brightening during 1991–2005. A substantial contribution by TCC frequency changes to the brightening is also evident in spring and autumn.

Responses of Terrestrial Ecosystems’ Net Primary Productivity to Future Regional Climate Change in China

Science.gov (United States)

Zhao, Dongsheng; Wu, Shaohong; Yin, Yunhe

2013-01-01

The impact of regional climate change on net primary productivity (NPP) is an important aspect in the study of ecosystems’ response to global climate change. China’s ecosystems are very sensitive to climate change owing to the influence of the East Asian monsoon. The Lund–Potsdam–Jena Dynamic Global Vegetation Model for China (LPJ-CN), a global dynamical vegetation model developed for China’s terrestrial ecosystems, was applied in this study to simulate the NPP changes affected by future climate change. As the LPJ-CN model is based on natural vegetation, the simulation in this study did not consider the influence of anthropogenic activities. Results suggest that future climate change would have adverse effects on natural ecosystems, with NPP tending to decrease in eastern China, particularly in the temperate and warm temperate regions. NPP would increase in western China, with a concentration in the Tibetan Plateau and the northwest arid regions. The increasing trend in NPP in western China and the decreasing trend in eastern China would be further enhanced by the warming climate. The spatial distribution of NPP, which declines from the southeast coast to the northwest inland, would have minimal variation under scenarios of climate change. PMID:23593325

Changes in "hotter and wetter" events across China

Science.gov (United States)

Liu, C.; Deng, H.; Lu, Y.; Qiu, X.; Wang, D.

2017-12-01

As global warming intensifies, efforts to understand the changes in extreme climate events have increased in recent years. A combined analysis of the changes in extreme temperature and precipitation events is presented in this paper. Using observational data from 1961 to 2015, a set of hotter and wetter (HW) events is defined, and we examine the changes in these events across China. The results show that more HW events occur in Central and Eastern China than in other subregions, especially in South China (SC). The rate of increase in HW events is 2.7 and 1.9 per decade in SC and East China (EC), respectively. In China, most HW events occurred in the last 20 years of the study period, indicating that China entered a period of high-frequency HW events. Indeed, the range in anomalies in the torrential rain days is greater than that of the high-temperature days in Northwest China (NWC), Central China (CC), and EC after the mid- to late 1990s. The opposite pattern is found in Northeast China (NEC), Southwest China-region 1 (SWC1), Southwest China-region 2 (SWC2), and SC. Finally, the increase in HW events in most regions of China is closely associated with warming.

A New Zincian Greenockite Occurrence in the Saishitang Cu Skarn Deposit, Qinghai Province, Northwest China

Directory of Open Access Journals (Sweden)

Jianping Liu

2017-07-01

Full Text Available Zn-Cd-S series minerals not only comprise industrial resources for Zn and Cd, but are also significant mineralogical indicators for hydrothermal ore-forming processes. Due to its unique formation conditions and rare occurrence, our understanding of the formation of zincian greenockite in natural systems is limited. Zincian greenockite was discovered during mineralogical studies in the Saishitang Cu skarn deposit, Qinghai Province, Northwest China. This provided an ideal opportunity to assess the occurrence and formation of zincian greenockite in skarn-type deposits. Ore minerals were observed using reflected-light microscopy, and the zincian greenockite was further analyzed using electron-probe microanalysis (EPMA and X-ray diffraction (XRD. The zincian greenockite occurs in the bornite–chalcopyrite ores and is composed of subhedral to anhedral grains approximately 50 × 150 μm2 to 200 × 300 μm2 in size, replaces the bornite, and is replaced by native silver. Two phases (I and II were identified based on back-scattered electron images, X-ray element-distributions maps, and EPMA data. The textural relationship indicated that Phase I was replaced by Phase II. Phase I contained high Zn (14.6 to 21.7 mol % ZnS and low Cd (72.4 to 82.2 mol % CdS, while Phase II contained low Zn (5.6 to 9.1 mol % ZnS and high Cd (85.4 to 89.9 mol % CdS. The zincian greenockite was formed at temperature of 300~270 °C during the transformation from a reducing environment to an oxidizing one in the late stage of the mineralization process in the Saishitang deposit.

Long-Term Effect of Manure and Fertilizer on Soil Organic Carbon Pools in Dryland Farming in Northwest China

Science.gov (United States)

Liu, Enke; Yan, Changrong; Mei, Xurong; Zhang, Yanqing; Fan, Tinglu

2013-01-01

An understanding of the dynamics of soil organic carbon (SOC) as affected by farming practices is imperative for maintaining soil productivity and mitigating global warming. The objectives of this study were to investigate the effects of long-term fertilization on SOC and SOC fractions for the whole soil profile (0–100 cm) in northwest China. The study was initiated in 1979 in Gansu, China and included six treatments: unfertilized control (CK), nitrogen fertilizer (N), nitrogen and phosphorus (P) fertilizers (NP), straw plus N and P fertilizers (NP+S), farmyard manure (FYM), and farmyard manure plus N and P fertilizers (NP+FYM). Results showed that SOC concentration in the 0–20 cm soil layer increased with time except in the CK and N treatments. Long-term fertilization significantly influenced SOC concentrations and storage to 60 cm depth. Below 60 cm, SOC concentrations and storages were statistically not significant between all treatments. The concentration of SOC at different depths in 0–60 cm soil profile was higher under NP+FYM follow by under NP+S, compared to under CK. The SOC storage in 0–60 cm in NP+FYM, NP+S, FYM and NP treatments were increased by 41.3%, 32.9%, 28.1% and 17.9%, respectively, as compared to the CK treatment. Organic manure plus inorganic fertilizer application also increased labile soil organic carbon pools in 0–60 cm depth. The average concentration of particulate organic carbon (POC), dissolved organic carbon (DOC) and microbial biomass carbon (MBC) in organic manure plus inorganic fertilizer treatments (NP+S and NP+FYM) in 0–60 cm depth were increased by 64.9–91.9%, 42.5–56.9%, and 74.7–99.4%, respectively, over the CK treatment. The POC, MBC and DOC concentrations increased linearly with increasing SOC content. These results indicate that long-term additions of organic manure have the most beneficial effects in building carbon pools among the investigated types of fertilization. PMID:23437161

Strategy and plan for siting and licensing a Rocky Mountain low-level radioactive waste facility

International Nuclear Information System (INIS)

Whitman, M.

1983-09-01

In 1979, the States of Nevada and Washington temporarily closed their commercial low-level radioactive waste (LLW) disposal facilities and South Carolina, the only other state hosting such a facility, restricted the amount of waste it would accept. All three states then announced that they did not intend to continue the status quo of accepting all of the country's commercial low-level radioactive waste. Faced with this situation, other states began considering alternative LLW management and disposal options. In the Rocky Mountain region, this evolved into discussions for the development of an interstate compact to manage low-level waste. Inherent in this management plan was a strategy to site and license a new LLW disposal facility for the Rocky Mountain region. The Rocky Mountain Low-Level Radioactive Waste Compact was negotiated over the course of a year, with final agreement on the language of the compact agreed to in early 1982. States eligible to join the compact are Arizona, Colorado, Nevada, New Mexico, Utah, and Wyoming. Colorado adopted the compact into law in 1982, and Nevada, New Mexico and Wyoming adopted it in 1983. Utah has joined the Northwest Compact, although it may decide to join the Rocky Mountain Compact after a new disposal facility is developed for the region. Arizona has taken no action on the Rocky Mountain Compact

Evaluation of Climate Change in northeastern China by means of d13C in tree-rings in the Great Xiang'An mountains region

Science.gov (United States)

Zhang, Qiqin; Lopez Caceres, Maximo Larry; Sugimoto, Atsuko; Wang, Xiaochun; Liu, Binhui

2017-04-01

The northeastern forest region of China represents one of the southern boundary of the Asian boreal forest and also represents the boundary between humid- semi humid area and arid- semi arid area of China. These forests are mainly dominated by larch (Larix gmelinii) stands with small areas covered by birch and pine forests. Increases in air temperature and precipitation caused by climate change are expected to have a great effect on forest ecosystems boundaries. Accordingly, from 1963-2006, air temperature has increased 1.5℃ in this region. Tree-ring chronologies are commonly used as indicator of climate changes and in recent decades the combination with carbon stable isotopes has shown a higher resolution in the results. Since this combine technique has not been used in northeastern China, we applied this combined technique to reconstruct the climate in the Great Xing'an mountains of northeastern China. Preliminary results showed that tree growth has increased in the middle and southernmost site in the last century while in the northernmost site it decreased for the same period which is in agreement with the mean air temperature increase from south to north in this region under negligible changes in precipitation regime. In contrast, tree-ring δ13C shows a gradual but steady increase along the three sites selected for our study, however the highest being observed in the middle site which experience the largest increased in air temperature in the last decade. This appears to indicate that increases in air temperature produced a stress in the stomatal conductance that so far has translated into tree ring growth decline.

Assessing vulnerability of giant pandas to climate change in the Qinling Mountains of China.

Science.gov (United States)

Li, Jia; Liu, Fang; Xue, Yadong; Zhang, Yu; Li, Diqiang

2017-06-01

Climate change might pose an additional threat to the already vulnerable giant panda ( Ailuropoda melanoleuca ). Effective conservation efforts require projections of vulnerability of the giant panda in facing climate change and proactive strategies to reduce emerging climate-related threats. We used the maximum entropy model to assess the vulnerability of giant panda to climate change in the Qinling Mountains of China. The results of modeling included the following findings: (1) the area of suitable habitat for giant pandas was projected to decrease by 281 km 2 from climate change by the 2050s; (2) the mean elevation of suitable habitat of giant panda was predicted to shift 30 m higher due to climate change over this period; (3) the network of nature reserves protect 61.73% of current suitable habitat for the species, and 59.23% of future suitable habitat; (4) current suitable habitat mainly located in Chenggu, Taibai, and Yangxian counties (with a total area of 987 km 2 ) was predicted to be vulnerable. Assessing the vulnerability of giant panda provided adaptive strategies for conservation programs and national park construction. We proposed adaptation strategies to ameliorate the predicted impacts of climate change on giant panda, including establishing and adjusting reserves, establishing habitat corridors, improving adaptive capacity to climate change, and strengthening monitoring of giant panda.

Warming-induced upward migration of the alpine treeline in the Changbai Mountains, northeast China.

Science.gov (United States)

Du, Haibo; Liu, Jie; Li, Mai-He; Büntgen, Ulf; Yang, Yue; Wang, Lei; Wu, Zhengfang; He, Hong S

2018-03-01

Treeline responses to environmental changes describe an important phenomenon in global change research. Often conflicting results and generally too short observations are, however, still challenging our understanding of climate-induced treeline dynamics. Here, we use a state-of-the-art dendroecological approach to reconstruct long-term changes in the position of the alpine treeline in relation to air temperature at two sides in the Changbai Mountains in northeast China. Over the past 160 years, the treeline increased by around 80 m, a process that can be divided into three phases of different rates and drives. The first phase was mainly influenced by vegetation recovery after an eruption of the Tianchi volcano in 1702. The slowly upward shift in the second phase was consistent with the slowly increasing temperature. The last phase coincided with rapid warming since 1985, and shows with 33 m per 1°C, the most intense upward shift. The spatial distribution and age structure of trees beyond the current treeline confirm the latest, warming-induced upward shift. Our results suggest that the alpine treeline will continue to rise, and that the alpine tundra may disappear if temperatures will increase further. This study not only enhances mechanistic understanding of long-term treeline dynamics, but also highlights the effects of rising temperatures on high-elevation vegetation dynamics. © 2017 John Wiley & Sons Ltd.

Evapotranspiration and water yield over China's landmass from 2000 to 2010

Science.gov (United States)

Liu, Y.; Zhou, Y.; Ju, W.; Chen, J.; Wang, S.; He, H.; Wang, H.; Guan, D.; Zhao, F.; Li, Y.; Hao, Y.

2013-12-01

Terrestrial carbon and water cycles are interactively linked at various spatial and temporal scales. Evapotranspiration (ET) plays a key role in the terrestrial water cycle, altering carbon sequestration of terrestrial ecosystems. The study of ET and its response to climate and vegetation changes is critical in China because water availability is a limiting factor for the functioning of terrestrial ecosystems in vast arid and semiarid regions. To constrain uncertainties in ET estimation, the process-based Boreal Ecosystem Productivity Simulator (BEPS) model was employed in conjunction with a newly developed leaf area index (LAI) data set, MODIS land cover, meteorological, and soil data to simulate daily ET and water yield at a spatial resolution of 500 m over China for the period from 2000 to 2010. The spatial and temporal variations of ET and water yield were analyzed. The influences of climatic factors (temperature and precipitation) and vegetation (land cover types and LAI) on these variations were assessed. Validations against ET measured at five ChinaFLUX sites showed that the BEPS model was able to simulate daily and annual ET well at site scales. Simulated annual ET exhibited a distinguishable southeast to northwest decreasing gradient, corresponding to climate conditions and vegetation types. It increased with the increase of LAI in 74% of China's landmass and was positively correlated with temperature in most areas of southwest, south, east, and central China. The correlation between annual ET and precipitation was positive in the arid and semiarid areas of northwest and north China, but negative in the Tibetan Plateau and humid southeast China. The national annual ET varied from 345.5 mm in 2001 to 387.8 mm in 2005, with an average of 369.8 mm during the study period. The overall rate of increase, 1.7 mm yr-1 (R2 = 0.18, p = 0.19), was mainly driven by the increase of total ET in forests. During 2006-2009, precipitation and LAI decreased widely and

Soil Susceptibility to Macropore Flow Across a Desert-Oasis Ecotone of the Hexi Corridor, Northwest China

Science.gov (United States)

Zhang, Yongyong; Zhao, Wenzhi; He, Jianhua; Fu, Li

2018-02-01

Macropore flow not only provides a fast pathway for water and solute transport and increases the risks of water and nutrient loss but also enhances soil aeration and groundwater recharge. However, macropore flow characteristics in irrigated oasis soils subject to continuous crop cultivation are poorly understood. This study was to investigate the effect of continuous cultivation on soil properties and macropore flow and to quantify the changes in macropore flow characteristics in an old oasis field (>50 years of cultivation, OOF), young oasis field (20 years, YOF), and adjacent uncultivated sandy area (0 year, USL) in Northwest China. Triplicate soil samples were collected from each site to investigate soil properties. Dye tracer experiments with also three replicates were conducted at each site. The degree of macropore flow (i.e., parameters of macropore flow) was highest at the OOF, intermediate at the YOF, and minimal at the USL. The macropore flow fraction (i.e., fraction of total infiltration flows through macropore flow pathways) at the OOF was 3.4 times greater than at the USL. The heterogeneous infiltration pattern at the OOF was dominated by macropore flow, while funnel flow was predominant at the USL. Long-term irrigation with silt-laden river water has increased silt + clay contents of the oasis soils. Irrigation and high-input crop cultivation also increased organic matter. These changes in soil properties contributed to the interaggregate voids formation. The conversion of native desert soils to irrigated croplands increases the degree of macropore flow, which might enhance groundwater recharge in the desert-oasis ecotone.

Human paleodiet and animal utilization strategies during the Bronze Age in northwest Yunnan Province, southwest China.

Directory of Open Access Journals (Sweden)

Lele Ren

Full Text Available Reconstructing ancient diets and the use of animals and plants augment our understanding of how humans adapted to different environments. Yunnan Province in southwest China is ecologically and environmentally diverse. During the Neolithic and Bronze Age periods, this region was occupied by a variety of local culture groups with diverse subsistence systems and material culture. In this paper, we obtained carbon (δ13C and nitrogen (δ15N isotopic ratios from human and faunal remains in order to reconstruct human paleodiets and strategies for animal exploitation at the Bronze Age site of Shilinggang (ca. 2500 Cal BP in northwest Yunnan Province. The δ13C results for human samples from Shilinggang demonstrate that people's diets were mainly dominated by C3-based foodstuffs, probably due to both direct consumption of C3 food and as a result of C3 foddering of consumed animals. Auxiliary C4 food signals can also be detected. High δ15N values indicate that meat was an important component of the diet. Analysis of faunal samples indicates that people primarily fed pigs and dogs with human food waste, while sheep/goats and cattle were foddered with other food sources. We compare stable isotope and archaeobotanical data from Shilinggang with data from other Bronze Age sites in Yunnan to explore potential regional variation in subsistence strategies. Our work suggests that people adopted different animal utilization and subsistence strategies in different parts of Yunnan during the Bronze Age period, probably as local adaptations to the highly diversified and isolated environments in the region.

Land desertification monitoring and assessment in Yulin of Northwest China using remote sensing and geographic information systems (GIS).

Science.gov (United States)

Zhang, Yuanzhi; Chen, Zhengyi; Zhu, Boqin; Luo, Xiuyue; Guan, Yanning; Guo, Shan; Nie, Yueping

2008-12-01

The objective of this study is to develop techniques for assessing and analysing land desertification in Yulin of Northwest China, as a typical monitoring region through the use of remotely sensed data and geographic information systems (GIS). The methodology included the use of Landsat TM data from 1987, 1996 and 2006, supplemented by aerial photos in 1960, topographic maps, field work and use of other existing data. From this, land cover, the Normalised Difference Vegetation Index (NDVI), farmland, woodland and grassland maps at 1:100,000 were prepared for land desertification monitoring in the area. In the study, all data was entered into a GIS using ILWIS software to perform land desertification monitoring. The results indicate that land desertification in the area has been developing rapidly during the past 40 years. Although land desertification has to some extent been controlled in the area by planting grasses and trees, the issue of land desertification is still serious. The study also demonstrates an example of why the integration of remote sensing with GIS is critical for the monitoring of environmental changes in arid and semi-arid regions, e.g. in land desertification monitoring in the Yulin pilot area. However, land desertification monitoring using remote sensing and GIS still needs to be continued and also refined for the purpose of long-term monitoring and the management of fragile ecosystems in the area.

Mapping of wind energy potential over the Gobi Desert in Northwest China based on multiple sources of data

Science.gov (United States)

Li, Li; Wang, Xinyuan; Luo, Lei; Zhao, Yanchuang; Zong, Xin; Bachagha, Nabil

2018-06-01

In recent years, wind energy has been a fastgrowing alternative source of electrical power due to its sustainability. In this paper, the wind energy potential over the Gobi Desert in Northwest China is assessed at the patch scale using geographic information systems (GIS). Data on land cover, topography, and administrative boundaries and 11 years (2000‒2010) of wind speed measurements were collected and used to map and estimate the region's wind energy potential. Based on the results, it was found that continuous regions of geographical potential (GeoP) are located in the middle of the research area (RA), with scattered areas of similar GeoP found in other regions. The results also show that the technical potential (TecP) levels are about 1.72‒2.67 times (2.20 times on average) higher than the actual levels. It was found that the GeoP patches can be divided into four classes: unsuitable regions, suitable regions, more suitable regions, and the most suitable regions. The GeoP estimation shows that 0.41 billion kW of wind energy are potentially available in the RA. The suitable regions account for 25.49%, the more suitable regions 24.45%, and the most suitable regions for more than half of the RA. It is also shown that Xinjiang and Gansu are more suitable for wind power development than Ningxia.

Explaining the species richness of birds along a subtropical elevational gradient in the Hengduan Mountains

DEFF Research Database (Denmark)

Wu, Yongjie; Colwell, Robert K.; Rahbek, Carsten

2013-01-01

AimTo document the species richness pattern of birds in the Hengduan Mountains and to understand its causes. LocationHengduan Mountains, China. MethodsSpecies richness of 738 breeding bird species was calculated for each 100-m elevational band along a gradient from 100 to 6000m a.s.l. Climate data...... were compiled based on monthly records from 182 meteorological stations in the Hengduan Mountains from 1959 to 2004. We calculated the planimetric area, predicted richness under geometric constraints, three-year average NDVI (normalized difference vegetation index) and EVI (enhanced vegetation index...... that climatic and energy factors correlate well with the richness pattern of birds, and that on the surveyed subtropical mountain, the elevational bands with highest seasonality harbour fewer species than areas with less seasonal variation in temperature. The results, however, vary somewhat among taxonomic...

Performance analysis of conventional and sloped solar chimney power plants in China

International Nuclear Information System (INIS)

Cao Fei; Zhao Liang; Li Huashan; Guo Liejin

2013-01-01

The solar chimney power plant (SCPP) has been accepted as one of the most promising approaches for future large-scale solar energy applications. This paper reports on a heat transfer model that is used to compare the performance of a conventional solar chimney power plant (CSCPP) and two sloped solar chimney power plants (SSCPPs) with the collector oriented at 30° and 60°, respectively. The power generation from SCPPs at different latitudes in China is also analyzed. Results indicate that the larger solar collector angle leads to improved performance in winter but results in lower performance in summer. It is found that the optimal collector angle to achieve the maximum power in Lanzhou, China, is around 60°. Main factors that influence the performance of SCPPs also include the system height and the air thermophysical characteristics. The ground energy loss, reflected solar radiation, and kinetic loss at the chimney outlet are the main energy losses in SCPPs. The studies also show SSCPPs are more suitable for high latitude regions in Northwest China, but CSCPPs are suggested to be built in southeastern and eastern parts of China with the combination to the local agriculture. - Highlights: ► The optimum collector angle for maximum power generation is 60° in Lanzhou. ► Main parameters influencing performances are the system height and air property. ► Ground loss, reflected loss and outlet kinetic loss are the main energy losses. ► The sloped styles are suitable for Northwest China. ► The conventional styles are suitable for Southeast and East China.

Climate Change and Neotectonic History of Northwestern China

Science.gov (United States)

Farr, Tom G.; Chadwick, Oliver; Evans, Diane; Gillespie, Alan; Peltzer, Gilles; Tapponnier, Paul

1996-01-01

The progress, results and future plans for the following objectives are presented: (1) To compare the types, rates, and magnitudes of surficial modification processes that have operated in Northwest China and the Southwestern U.S.; (2) To quantify and understand the basis of the remote sensing signatures of these processes to allow extrapolation from field sites to regional maps and to allow comparisons between widely separated arid regions; (3) To use the resulting chronologies to help define the temporal and spatial distribution of continental climate changes; and (4) Determine the ages of movements on some of the active faults in Northwestern China.

Understanding snow-transport processes shaping the mountain snow-cover

Directory of Open Access Journals (Sweden)

R. Mott

2010-12-01

Full Text Available Mountain snow-cover is normally heterogeneously distributed due to wind and precipitation interacting with the snow cover on various scales. The aim of this study was to investigate snow deposition and wind-induced snow-transport processes on different scales and to analyze some major drift events caused by north-west storms during two consecutive accumulation periods. In particular, we distinguish between the individual processes that cause specific drifts using a physically based model approach. Very high resolution wind fields (5 m were computed with the atmospheric model Advanced Regional Prediction System (ARPS and used as input for a model of snow-surface processes (Alpine3D to calculate saltation, suspension and preferential deposition of precipitation. Several flow features during north-west storms were identified with input from a high-density network of permanent and mobile weather stations and indirect estimations of wind directions from snow-surface structures, such as snow dunes and sastrugis. We also used Terrestrial and Airborne Laser Scanning measurements to investigate snow-deposition patterns and to validate the model. The model results suggest that the in-slope deposition patterns, particularly two huge cross-slope cornice-like drifts, developed only when the prevailing wind direction was northwesterly and were formed mainly due to snow redistribution processes (saltation-driven. In contrast, more homogeneous deposition patterns on a ridge scale were formed during the same periods mainly due to preferential deposition of precipitation. The numerical analysis showed that snow-transport processes were sensitive to the changing topography due to the smoothing effect of the snow cover.

Vegetation and Climate Change during the Last Deglaciation in the Great Khingan Mountain, Northeastern China.

Science.gov (United States)

Wu, Jing; Liu, Qiang; Wang, Luo; Chu, Guo-qiang; Liu, Jia-qi

2016-01-01

The Great Khingan Mountain range, Northeast China, is located on the northern limit of modern East Asian Summer Monsoon (EASM) and thus highly sensitive to the extension of the EASM from glacial to interglacial modes. Here, we present a high-resolution pollen record covering the last glacial maximum and the early Holocene from a closed crater Lake Moon to reconstruct vegetation history during the glacial-interglacial transition and thus register the evolution of the EASM during the last deglaciation. The vegetation history has gone through distinct changes from subalpine meadow in the last glacial maximum to dry steppe dominated by Artemisia from 20.3 to 17.4 ka BP, subalpine meadow dominated by Cyperaceae and Artemisia between 17.4 and 14.4 ka BP, and forest steppe dominated by Betula and Artemisia after 14.4 ka BP. The pollen-based temperature index demonstrates a gradual warming trend started at around 20.3 ka BP with interruptions of several brief events. Two cold conditions occurred around at 17.2-16.6 ka BP and 12.8-11.8 ka BP, temporally correlating to the Henrich 1 and the Younger Dryas events respectively, 1and abrupt warming events occurred around at 14.4 ka BP and 11.8 ka BP, probably relevant to the beginning of the Bølling-Allerød stages and the Holocene. The pollen-based moisture proxy shows distinct drought condition during the last glacial maximum (20.3-18.0 ka BP) and the Younger Dryas. The climate history based on pollen record of Lake Moon suggests that the regional temperature variability was coherent with the classical climate in the North Atlantic, implying the dominance of the high latitude processes on the EASM evolution from the Last Glacial Maximum (LGM) to early Holocene. The local humidity variability was influenced by the EASM limitedly before the Bølling-Allerød warming, which is mainly controlled by the summer rainfall due to the EASM front covering the Northeast China after that.

Vegetation and Climate Change during the Last Deglaciation in the Great Khingan Mountain, Northeastern China.

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Jing Wu

Full Text Available The Great Khingan Mountain range, Northeast China, is located on the northern limit of modern East Asian Summer Monsoon (EASM and thus highly sensitive to the extension of the EASM from glacial to interglacial modes. Here, we present a high-resolution pollen record covering the last glacial maximum and the early Holocene from a closed crater Lake Moon to reconstruct vegetation history during the glacial-interglacial transition and thus register the evolution of the EASM during the last deglaciation. The vegetation history has gone through distinct changes from subalpine meadow in the last glacial maximum to dry steppe dominated by Artemisia from 20.3 to 17.4 ka BP, subalpine meadow dominated by Cyperaceae and Artemisia between 17.4 and 14.4 ka BP, and forest steppe dominated by Betula and Artemisia after 14.4 ka BP. The pollen-based temperature index demonstrates a gradual warming trend started at around 20.3 ka BP with interruptions of several brief events. Two cold conditions occurred around at 17.2-16.6 ka BP and 12.8-11.8 ka BP, temporally correlating to the Henrich 1 and the Younger Dryas events respectively, 1and abrupt warming events occurred around at 14.4 ka BP and 11.8 ka BP, probably relevant to the beginning of the Bølling-Allerød stages and the Holocene. The pollen-based moisture proxy shows distinct drought condition during the last glacial maximum (20.3-18.0 ka BP and the Younger Dryas. The climate history based on pollen record of Lake Moon suggests that the regional temperature variability was coherent with the classical climate in the North Atlantic, implying the dominance of the high latitude processes on the EASM evolution from the Last Glacial Maximum (LGM to early Holocene. The local humidity variability was influenced by the EASM limitedly before the Bølling-Allerød warming, which is mainly controlled by the summer rainfall due to the EASM front covering the Northeast China after that.

Changes of evapotranspiration and water yield in China's terrestrial ecosystems during the period from 2000 to 2010

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Liu, Y.; Zhou, Y.; Ju, W.; Chen, J.; Wang, S.; He, H.; Wang, H.; Guan, D.; Zhao, F.; Li, Y.; Hao, Y.

2013-04-01

Terrestrial carbon and water cycles are interactively linked at various spatial and temporal scales. Evapotranspiration (ET) plays a key role in the terrestrial water cycle and altering carbon sequestration of terrestrial ecosystems. The study of ET and its response to climate and vegetation changes is critical in China since water availability is a limiting factor for the functioning of terrestrial ecosystems in vast arid and semiarid regions. In this study, the process-based Boreal Ecosystem Productivity Simulator (BEPS) model was employed in conjunction with a newly developed leaf area index (LAI) dataset and other spatial data to simulate daily ET and water yield at a spatial resolution of 500 m over China for the period from 2000 to 2010. The spatial and temporal variations of ET and water yield and influences of temperature, precipitation, land cover types, and LAI on ET were analyzed. The validations with ET measured at 5 typical ChinaFLUX sites and inferred using statistical hydrological data in 10 basins showed that the BEPS model was able to simulate daily and annual ET well at site and basin scales. Simulated annual ET exhibited a distinguishable southeast to northwest decreasing gradient, corresponding to climate conditions and vegetation types. It increased with the increase of LAI in 74% of China's landmass and was positively correlated with temperature in most areas of southwest, south, east, and central China and with precipitation in the arid and semiarid areas of northwest and north China. In the Tibet Plateau and humid southeast China, the increase in precipitation might cause ET to decrease. The national mean annual ET varied from 345.5 mm yr-1 in 2001 to 387.8 mm yr-1 in 2005, with an average of 369.8 mm yr-1 during the study period. The overall increase rate of 1.7 mm yr-2 (r = 0.43 p = 0.19) was mainly driven by the increase of total ET in forests. During the period from 2006 to 2009, precipitation and LAI decreased widely and consequently

Modeling flash floods in ungauged mountain catchments of China: A decision tree learning approach for parameter regionalization

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Ragettli, S.; Zhou, J.; Wang, H.; Liu, C.

2017-12-01

Flash floods in small mountain catchments are one of the most frequent causes of loss of life and property from natural hazards in China. Hydrological models can be a useful tool for the anticipation of these events and the issuing of timely warnings. Since sub-daily streamflow information is unavailable for most small basins in China, one of the main challenges is finding appropriate parameter values for simulating flash floods in ungauged catchments. In this study, we use decision tree learning to explore parameter set transferability between different catchments. For this purpose, the physically-based, semi-distributed rainfall-runoff model PRMS-OMS is set up for 35 catchments in ten Chinese provinces. Hourly data from more than 800 storm runoff events are used to calibrate the model and evaluate the performance of parameter set transfers between catchments. For each catchment, 58 catchment attributes are extracted from several data sets available for whole China. We then use a data mining technique (decision tree learning) to identify catchment similarities that can be related to good transfer performance. Finally, we use the splitting rules of decision trees for finding suitable donor catchments for ungauged target catchments. We show that decision tree learning allows to optimally utilize the information content of available catchment descriptors and outperforms regionalization based on a conventional measure of physiographic-climatic similarity by 15%-20%. Similar performance can be achieved with a regionalization method based on spatial proximity, but decision trees offer flexible rules for selecting suitable donor catchments, not relying on the vicinity of gauged catchments. This flexibility makes the method particularly suitable for implementation in sparsely gauged environments. We evaluate the probability to detect flood events exceeding a given return period, considering measured discharge and PRMS-OMS simulated flows with regionalized parameters

New Energy Villages in Taiwan and China

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Lee, C. S.; Wang, S. C.

2015-12-01

Taiwan locates in the active tectonic subdution and collision belts, therefore, the geothermal gradient is very high and have found 128 sites of high geothermal areas; 20% of them have the temperature between 75 - 200 degree C in which they can be directly used for the electricity generation; 50% of them are in 50 - 74 degree C and the rest 30% are below 50 degree C. These areas need the deep drillings to get into higher temperature for power energy. The first 20% high temperature areas are mostly located in the coastal or mountain regions. The government is interesting to develop these areas as the "New Energy Villages" so that they can not only become self-energy sufficient sites, but also to protect themself from being the loss of electricity and water during the typhoon and earthquake hazards. The multiple usages of hot water (such as the first power generation and then the hot spring utilization) have its merits. China, in the other hand, is not within the present-day active tectonic zone. However, the recent Sino Probe Experiments (Deep Exploration in China) have mapped the Cetaceous plate boundaries in the coast of China. The heat is still possibly migrating to near the surface through the existing structures. For example, the Feng Shun Geothermal Power Station in north of Guangzhou, Guangdong Province, used the 96 degree C hot water from a well of 800 m producing a small amount of 300 KW power since 1984. The Guangdong Province is located in the edge of Mesozoic South China Plate. Further in land, the Huang Mountain, one of the world heritage sites, is located at the boundary of another Mesozoic Yangtze River Plate. There is not a geothermal power plant; however, a number of hot springs are in a booming tour business at the foot hill of the mountain. The electricity has to come from a long way of net working. If China develops the local, small, but sufficient power plants by using the modern geothermal exploration and drilling techniques. The "New Energy

Waves in the Red Sea: Response to monsoonal and mountain gap winds

KAUST Repository

Ralston, David K.

2013-08-01

An unstructured grid, phase-averaged wave model forced with winds from a high resolution atmospheric model is used to evaluate wind wave conditions in the Red Sea over an approximately 2-year period. The Red Sea lies in a narrow rift valley, and the steep topography surrounding the basin steers the dominant wind patterns and consequently the wave climate. At large scales, the model results indicated that the primary seasonal variability in waves was due to the monsoonal wind reversal. During the winter, monsoon winds from the southeast generated waves with mean significant wave heights in excess of 2. m and mean periods of 8. s in the southern Red Sea, while in the northern part of the basin waves were smaller, shorter period, and from northwest. The zone of convergence of winds and waves typically occurred around 19-20°N, but the location varied between 15 and 21.5°N. During the summer, waves were generally smaller and from the northwest over most of the basin. While the seasonal winds oriented along the axis of the Red Sea drove much of the variability in the waves, the maximum wave heights in the simulations were not due to the monsoonal winds but instead were generated by localized mountain wind jets oriented across the basin (roughly east-west). During the summer, a mountain wind jet from the Tokar Gap enhanced the waves in the region of 18 and 20°N, with monthly mean wave heights exceeding 2. m and maximum wave heights of 14. m during a period when the rest of the Red Sea was relatively calm. Smaller mountain gap wind jets along the northeast coast created large waves during the fall and winter, with a series of jets providing a dominant source of wave energy during these periods. Evaluation of the wave model results against observations from a buoy and satellites found that the spatial resolution of the wind model significantly affected the quality of the wave model results. Wind forcing from a 10-km grid produced higher skills for waves than winds from a

Geological Factors and Reservoir Properties Affecting the Gas Content of Coal Seams in the Gujiao Area, Northwest Qinshui Basin, China

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Zhuo Zou

2018-04-01

Full Text Available Coalbed methane (CBM well drilling and logging data together with geological data were adopted to provide insights into controlling mechanism of gas content in major coal seams and establish gas accumulation models in the Gujiao area, Northwest Qinshui Basin, China. Gas content of targeted coals is various in the Gujiao area with their burial depth ranging from 295 to 859 m. Highly variable gas content of coals should be derived from the differences among tectonism, magmatism, hydrodynamism, and sedimentation. Gas content preserved in the Gujiao area is divided into two parts by the geological structure. Gas tends to accumulate in the groundwater stagnant zone with a total dissolved solids (TDS value of 1300–1700 ppm due to water pressure in the Gujiao area. Reservoir properties including moisture content, minerals, and pore structure also significantly result in gas content variability. Subsequently, the gray correlation statistic method was adopted to determine the most important factors controlling gas content. Coal metamorphism and geological structure had marked control on gas content for the targeted coals. Finally, the favorable CBM exploitation areas were comprehensively evaluated in the Gujiao area. The results showed that the most favorable CBM exploitation areas were in the mid-south part of the Gujiao area (Block I.

Successive monitoring surveys of selected banned and restricted pesticide residues in vegetables from the northwest region of China from 2011 to 2013.

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Yu, Yan; Hu, Senke; Yang, Yuxuan; Zhao, Xiaodan; Xue, Jianjun; Zhang, Jinghua; Gao, Song; Yang, Aimin

2017-08-02

A wide range of pesticides is applied for crop protection in vegetable cultivation in China. Regulation of pesticide maximum residue limits (MRLs) in vegetables is established but not fully enforced. And pesticide residues in vegetables were not well monitored. This study conducted the monitoring surveys from 2011 to 2013 to investigate the pesticides in vegetables in the northwest region of China. A multi-residue gas chromatography/mass spectrometry method (GC/MS) was used in determination of pesticides in vegetable samples. The χ 2 test was used to compare the concentration of pesticide residues. A total of 32 pesticide residues were detected in 518 samples from 20 types of vegetables in this study. 7.7% of the detected pesticide residues exceeded the MRLs. The percentages of residues that exceeded the MRLs for leafy, melon and fruit, and root vegetables were 11.2%, 5.1%, and 1.6%, respectively. There was no seasonal difference in the proportion of samples that exceeded the MRLs in different vegetables. A total of 84.3% (27/32) pesticides were detected at concentrations that exceeded MRLs. And of the 27 pesticides that exceeded the MRLs, 11 (40.7%) were banned for use in agriculture. The most frequently detected pesticides were Malathion (9.4%), Dichlorvos (8.7%), and Dimethoate (8.1%). The observed high rate of pesticides detected and high incidence of pesticide detection exceeding their MRLs in the commonly consumed vegetables indicated that the Good Agricultural Practices (GAP) may not be well followed. The management of pesticide use and control should be improved. Well-developed training programs should be initiated to improve pesticide application knowledge for farmers.

Forging Consensus for Implementing Youth Socialization Policy in Northwest China

Science.gov (United States)

Fairbrother, Gregory P.

2011-01-01

The goal of this article is to examine how the provincial education media in China play a role of forging consensus among local actors responsible for the implementation of new centrally-promulgated youth socialization policy. In doing so, it also explores the tension among three of the Chinese state's claims to legitimacy: economic development,…

[Natural regeneration of young Excentrodendron hsienmu in karst mountainous region in Southwest Guangxi, China].

Science.gov (United States)

Ou, Zhi-Yang; Su, Zhi-Yao; Peng, Yu-Hua; Hu, Qin-Fei; Huang, Xiao-Rong

2013-09-01

A field survey was conducted in the karst mountainous region in Pingguo County of Southwest Guangxi, China to explore the structural characteristics, spatial distribution pattern, and growth dynamics of young Excentrodendron hsienmu as well as the main environmental factors affecting the natural regeneration of the E. hsienmu population. In the study area, the population structure of the young E. hsienmu was stable, and exhibited a clumped spatial pattern for the seedlings and seedling sprouts. The ground diameter growth and height growth of the young E. hsienmu presented the same variation trend, i. e., the ground diameter increased with increasing height. The ground diameter growth and height growth of the E. hsienmu seedlings were limited by population density, i. e., decreased with increasing population density. The correlation analysis showed that the trees more than 2.5 m in height and the shrubs were the major stand factors affecting the natural regeneration of young E. hsienmu, while the herbs had no significant correlation with the regeneration. The percentage of covered rock also had no significant effects on the regeneration. Kruskal-Wallis ANOVA showed that there existed significant differences in the height and ground diameter of young E. hsienmu at different slope degrees and slope positions. The population density, height, and ground diameter had significant differences across slope aspects. The natural regeneration of young E. hsienmu was comprehensively affected by the species biological characteristics, intraspecific competition, interspecific competition, heterogeneous habitat, and anthropogenic disturbances.

Spatiotemporal pattern of bacillary dysentery in China from 1990 to 2009: what is the driver behind?

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Zhiwei Xu

Full Text Available Little is known about the spatiotemporal pattern of bacillary dysentery (BD in China. This study assessed the geographic distribution and seasonality of BD in China over the past two decades.Data on monthly BD cases in 31 provinces of China from January 1990 to December 2009 obtained from Chinese Center for Disease Control and Prevention, and data on demographic and geographic factors, as well as climatic factors, were compiled. The spatial distributions of BD in the four periods across different provinces were mapped, and heat maps were created to present the seasonality of BD by geography. A cosinor function combined with Poisson regression was used to quantify the seasonal parameters of BD, and a regression analysis was conducted to identify the potential drivers of morbidity and seasonality of BD.Although most regions of China have experienced considerable declines in BD morbidity over the past two decades, Beijing and Ningxia still had high BD morbidity in 2009. BD morbidity decreased more slowly in North-west China than other regions. BD in China mainly peaked from July to September, with heterogeneity in peak time between regions. Relative humidity was associated with BD morbidity and peak time, and latitude was the major predictor of BD amplitude.The transmission of BD was heterogeneous in China. Improved sanitation and hygiene in North-west China, and better access to clean water and food in the big floating population in some metropolises could be the focus of future preventive interventions against BD. BD control efforts should put more emphasis on those dry areas in summer.

Soils of Low-Mountain Landscapes of North Karelia

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Medvedeva, M. V.; Akhmetova, G. V.; Fedorets, N. G.; Yakovlev, A. S.; Raevskii, B. V.; Travin, V. V.

2018-02-01

Soils of low-mountain landscapes in the northwest of Karelia have been studied. The soil cover of the studied area is mainly represented by Al-Fe-humus soils (Podzols); thin soils (Leptosols) are widespread. Characteristic morphological features of all the studied soils are relatively shallow profiles, high stone content, and underlying by hard bedrock with fine earth material in crevices between large boulders. The studied soils have the high carbon and low nitrogen content, which points to unfavorable conditions of organic matter transformation. The content of most macro- and microelements is not high, which is typical for soils of the region; the content of copper and zinc exceeds the regional background two-three times. Regularities of the vertical zonality in the properties of soils of mountain ecosystems manifest themselves in decreasing thickness of the soil profile at higher altitude above sea level in parallel to decreasing thickness of the layer of loose rocks, while the stone content increases. In soils of the forest-tundra zone, the organomineral horizon with the high organic matter content is formed immediately under the forest litter. The litter horizon is the soils of this zone is characterized by increased concentrations of calcium, magnesium, phosphorus, and zinc.

Building information modelling review with potential applications in tunnel engineering of China

Science.gov (United States)

Zhou, Weihong; Qin, Haiyang; Qiu, Junling; Fan, Haobo; Lai, Jinxing; Wang, Ke; Wang, Lixin

2017-08-01

Building information modelling (BIM) can be applied to tunnel engineering to address a number of problems, including complex structure, extensive design, long construction cycle and increased security risks. To promote the development of tunnel engineering in China, this paper combines actual cases, including the Xingu mountain tunnel and the Shigu Mountain tunnel, to systematically analyse BIM applications in tunnel engineering in China. The results indicate that BIM technology in tunnel engineering is currently mainly applied during the design stage rather than during construction and operation stages. The application of BIM technology in tunnel engineering covers many problems, such as a lack of standards, incompatibility of different software, disorganized management, complex combination with GIS (Geographic Information System), low utilization rate and poor awareness. In this study, through summary of related research results and engineering cases, suggestions are introduced and an outlook for the BIM application in tunnel engineering in China is presented, which provides guidance for design optimization, construction standards and later operation maintenance.

Assessing Local and Surrounding Threats to the Protected Area Network in a Biodiversity Hotspot: The Hengduan Mountains of Southwest China.

Science.gov (United States)

Ye, Xin; Liu, Guohua; Li, Zongshan; Wang, Hao; Zeng, Yuan

2015-01-01

Protected areas (PAs) not only serve as refuges of biodiversity conservation but are also part of large ecosystems and are vulnerable to change caused by human activity from surrounding lands, especially in biodiversity hotspots. Assessing threats to PAs and surrounding areas is therefore a critical step in effective conservation planning. We apply a threat framework as a means of quantitatively assessing local and surrounding threats to different types of PAs with gradient buffers, and to main ecoregions in the Hengduan Mountain Hotspot of southwest China. Our findings show that national protected areas (NPAs) have lower and significantly lower threat values (pprotected areas (PPAs) and other protected areas (OPAs), respectively, which indicates that NPAs are lands with a lower threat level and higher levels of protection and management. PAs have clear edge effects, as the proportion of areas with low threat levels decline dramatically in the 5-kilometer buffers just outside the PAs. However, NPAs suffered greater declines (58.3%) than PPAs (34.8%) and OPAs (33.4%) in the 5-kilometer buffers. Moreover, a significant positive correlation was found between the size of PAs and the proportion of areas with low threat levels that they contained in both PAs and PA buffers (p<0.01). To control or mitigate current threats at the regional scale, PA managers often require quantitative information related to threat intensities and spatial distribution. The threat assessment in the Hengduan Mountain Hotspot will be useful to policy makers and managers in their efforts to establish effective plans and target-oriented management strategies.

In situ chemical composition measurement of individual cloud residue particles at a mountain site, southern China

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Q. Lin

2017-07-01

Full Text Available To investigate how atmospheric aerosol particles interact with chemical composition of cloud droplets, a ground-based counterflow virtual impactor (GCVI coupled with a real-time single-particle aerosol mass spectrometer (SPAMS was used to assess the chemical composition and mixing state of individual cloud residue particles in the Nanling Mountains (1690 m a. s. l. , southern China, in January 2016. The cloud residues were classified into nine particle types: aged elemental carbon (EC, potassium-rich (K-rich, amine, dust, Pb, Fe, organic carbon (OC, sodium-rich (Na-rich and Other. The largest fraction of the total cloud residues was the aged EC type (49.3 %, followed by the K-rich type (33.9 %. Abundant aged EC cloud residues that mixed internally with inorganic salts were found in air masses from northerly polluted areas. The number fraction (NF of the K-rich cloud residues increased within southwesterly air masses from fire activities in Southeast Asia. When air masses changed from northerly polluted areas to southwesterly ocean and livestock areas, the amine particles increased from 0.2 to 15.1 % of the total cloud residues. The dust, Fe, Pb, Na-rich and OC particle types had a low contribution (0.5–4.1 % to the total cloud residues. Higher fraction of nitrate (88–89 % was found in the dust and Na-rich cloud residues relative to sulfate (41–42 % and ammonium (15–23 %. Higher intensity of nitrate was found in the cloud residues relative to the ambient particles. Compared with nonactivated particles, nitrate intensity decreased in all cloud residues except for dust type. To our knowledge, this study is the first report on in situ observation of the chemical composition and mixing state of individual cloud residue particles in China.

Household photovoltaic market in Xining, Qingha province, China: the role of local PV business

International Nuclear Information System (INIS)

Ling, S.; Boardman, B.

2002-01-01

This paper assesses the present and future market for household photovoltaic (PV) systems in rural Northwest China, especially from the PV commerce at Xining, Qinghai Province. This unsubsidised free market is now met by the emerging PV industry in China, which includes cell and module manufacturers, and PV system distributors and assemblers. For widespread deployment of such a renewable energy technology, the development of a local free market seems more successful than donor- or 'government subsidy'-driven programmes. Presently, there is a thriving infant PV industry in Northwest China, mostly centred in Xining. Xining-based PV sales companies have extensive networks for selling, marketing and servicing household PV systems for rural farmers and nomads. Small systems are now ordinary items on sale in local shops. Based on interviews and fieldwork observations with seven major PV sales companies in Xining, the household PV market is assessed from the present business operations of these companies. Detail of primary sources is given with the aim of archiving seminal progress in the history of photovoltaic power. The results suggest that although the household PV market will continue to grow, current government and international sponsored PV programmes can create both opportunities and barriers for the infant PV market an industry in China. (author)

Topography and Data Mining Based Methods for Improving Satellite Precipitation in Mountainous Areas of China

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Ting Xia

2015-07-01

Full Text Available Topography is a significant factor influencing the spatial distribution of precipitation. This study developed a new methodology to evaluate and calibrate the Tropical Rainfall Measuring Mission Multi-satellite Precipitation Analysis (TMPA products by merging geographic and topographic information. In the proposed method, firstly, the consistency rule was introduced to evaluate the fitness of satellite rainfall with measurements on the grids with and without ground gauges. Secondly, in order to improve the consistency rate of satellite rainfall, genetic programming was introduced to mine the relationship between the gauge rainfall and location, elevation and TMPA rainfall. The proof experiment and analysis for the mean annual satellite precipitation from 2001–2012, 3B43 (V7 of TMPA rainfall product, was carried out in eight mountainous areas of China. The result shows that the proposed method is significant and efficient both for the assessment and improvement of satellite precipitation. It is found that the satellite rainfall consistency rates in the gauged and ungauged grids are different in the study area. In addition, the mined correlation of location-elevation-TMPA rainfall can noticeably improve the satellite precipitation, both in the context of the new criterion of the consistency rate and the existing criteria such as Bias and RMSD. The proposed method is also efficient for correcting the monthly and mean monthly rainfall of 3B43 and 3B42RT.

Natural regeneration of trees in three types of afforested stands in the Taihang Mountains, China.

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Xitian Yang

Full Text Available Natural regeneration is the natural process by which plants replace themselves. It is a cost-effective way to re-establish vegetation, and it helps to preserve genetic identity and diversity. In this study, we investigated the natural regeneration of trees in three types of afforested stands in the Taihang Mountains, China, which were dominated by Robinia pseudoacacia (black locust, Quercus variabilis (Chinese cork oak and Platycladus orientalis (Chinese arborvitae respectively. A consistent pattern was found among the three types of stands, being that the density of seedlings was positively correlated with the overstory canopy cover and negatively correlated with the covers of shrub, herb and litter layers. While a positive correlation between the density of seedlings and stand age was found for the conifer stands, negative correlations were found for the two types of broadleaf stands. Correlations between the density of saplings and the stand attributes were not consistent among the three types of stands. The two types of broadleaf stands had higher densities of seedlings and saplings than the conifer stands. While the broadleaf stands had adequate recruits for regeneration, the conifer stands did not have enough recruits. Our findings suggest that the overstory canopy should be prevented from being disturbed, any reduction of the canopy cover will decrease the recruits and affect the regeneration.

Spatiotemporal Variation of Karst Ecosystem Service Values and Its Correlation with Environmental Factors in Northwest Guangxi, China

Science.gov (United States)

Zhang, Mingyang; Zhang, Chunhua; Wang, Kelin; Yue, Yuemin; Qi, Xiangkun; Fan, Feide

2011-11-01

In this investigation we analyzed the spatiotemporal variation of ecosystem service values (ESVs) and its correlation with numerous environmental factors (EFs) for the karst region of Northwest Guangxi, China, from 1985 to 2005 using remote sensing, geographic information systems (GIS) and statistical techniques. The results indicate that historically ESVs for this karst region decreased from 1985 (109.652 billion Yuan) to 1990 (88.789 billion Yuan) and then increased at the turn of the twenty-first century. However, the ESVs in both 2000 (103.384 billion Yuan) and 2005 (106.257 billion Yuan) never achieved the level recorded in 1985. The total of nutrient cycling, organic production and gas regulation combined were 72.69, 64.57, 70.18 and 72.10% of ESVs in 1985, 1990, 2000 and 2005, respectively. In contrast, the ESVs of water conservation, soil reservation, recreation and culture were determined to be relatively low contributing only 17.44, 23.82, 19.26 and 24.76% of total ESVs, respectively, during these four years. With regards to the spatial distribution of ESVs, larger values were recorded in the west and smaller ones recorded in the east. The most significant factors that were deemed to influence ESVs are annual rainfall, per capita cropland, slope and vegetation coverage. Annual rainfall and slope exert a negative force, whereas per capita cropland and vegetation coverage exert a positive force on ESVs. The results of the study would suggest that ecosystem conditions of this important karst region have been improved as the result of the implementation of rocky desertification control policies.

[Soil sandy desertification and salinization and their interrelationships in Yanghuang irrigated area of Hongsipu, Ningxia of northwest China].

Science.gov (United States)

Yang, Xin-guo; Song, Nai-ping

2011-09-01

By the methods of controlled and typical sampling, this paper analyzed the texture, salinization characteristics, cation exchange capacity (CEC), and their correlations in the 0-40 cm soil profiles of corn land, medlar land, and non-utilized land in Yanghuang irrigated area of Hongsipu, Northwest China. Under controlled sampling, the salt content in the soil profiles was 0.69-1.30 g x kg(-1) (except in non-utilized land where the 0-10 cm soil salt content was up to 1.74 g x kg(-1)), with no obvious salinization. The sodium adsorption ratio and exchangeable sodium percentage in the 20-40 cm soil layer of medlar land were 12.18 and 14.1%, respectively, and the total content of clay and silt in the 0-40 cm soil profile of medlar land was up to 37.3% whereas that in the 0-20 cm soil layer of corn land was only 13.5%. In the 20-40 cm soil layer of corn land, the indices of sandy desertification and salinization had significant correlations under controlled sampling but no correlations under typical sampling, while the CEC and the sandy desertification and salinization indices had significant correlations under typical sampling. In different land use types in the study area, soil sandy desertification and salinization had complicated interrelationships, and CEC could be used as the indicator for the changes in soil environmental quality.

Chemical characterization of aerosols at the summit of Mountain Tai in Central East China

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C. Deng

2011-07-01

Full Text Available PM_2.5 and TSP samples were collected at the summit of Mountain Tai (MT (1534 m a.s.l. in spring 2006/2007 and summer 2006 to investigate the characteristics of aerosols over central eastern China. For comparison, aerosol samples were also collected at Tazhong, Urumqi, and Tianchi in Xinjiang in northwestern China, Duolun and Yulin in northern China, and two urban sites in the megacities, Beijing and Shanghai, in 2007. Daily mass concentrations of TSP and PM_2.5 ranged from 39.6–287.6 μg m⁻³ and 17.2–235.7 μg m⁻³ respectively at the summit of MT. Averaged concentrations of PM_2.5 showed a pronounced seasonal variation with higher concentration in summer than spring. 17 water-soluble ions (SO₄²⁻, NO₃⁻, Cl⁻, F⁻, PO₄³⁻, NO₂⁻, CH₃COO⁻, CH₂C₂O₄²⁻, C₂H₄C₂O₄²⁻, HCOO⁻, MSA, C₂O₄²⁻, NH₄⁺, Ca²⁺, K⁺, Mg²⁺, Na⁺, and 19 elements of all samples were measured. SO₄²⁻, NO₃⁻, and NH₄⁺ were the major water-soluble species in PM_2.5, accounting for 61.50 % and 72.65 % of the total measured ions in spring and summer, respectively. The average ratio of PM_2.5/TSP was 0.37(2006 and 0.49(2007 in spring, while up to 0.91 in summer, suggesting that aerosol particles were primarily comprised of fine particles in summer and of considerable coarse particles in spring. Crustal elements (e.g., Ca, Mg, Al, Fe, etc. showed higher concentration in spring than summer, while most of the pollution species (SO₄²⁻, NO₃⁻, K

Effects of Ethnic Settlements and Land Management Status on Species Distribution Patterns: A Case Study of Endangered Musk Deer (Moschus spp.) in Northwest Yunnan, China.

Science.gov (United States)

Li, Xueyou; Bleisch, William V; Jiang, Xuelong

2016-01-01

Understanding the status and spatial distribution of endangered species in biologically and ethnologically diverse areas is important to address correlates of cultural and biological diversity. We developed models for endangered musk deer (Moschus spp.) abundance indices in and around protected areas inhabited by different ethnic groups in northwest Yunnan China to address different anthropogenic and management-related questions. We found that prediction of relative abundance of musk deer was best accomplished using ethnicity of settlements, conservation status and poaching pressure in an area. Musk deer were around 5 times more abundant in Tibetan regions relative to Lisu regions. We found no significant negative correlates of gathering and transhumance activities on musk deer abundance. Hunting pressure showed no significant differences between protected and non-protected areas, but showed significant differences among ethnic groups. Hunting pressures in areas adjacent to Lisu settlements was 7.1 times more than in areas adjacent to Tibetan settlements. Our findings indicate protected areas in southwest China are not fully effective in deterring human disturbance caused by traditional practices. We suggest that conservation and management strategies should engage traditional culture and practices with a positive conservation impact. Better understanding of indigenous culture may open up new opportunities for species conservation in much wider tracts of unprotected and human-dominated lands. Traditional practices that are not destructive to biodiversity should be allowed as a way of providing a link between the local communities and protected areas thereby creating incentives for conservation.

Inter-Comparison and Evaluation of Remote Sensing Precipitation Products over China from 2005 to 2013

Directory of Open Access Journals (Sweden)

Qiaolin Zeng

2018-01-01

Full Text Available Precipitation is a key aspect of the climate system. In this paper, the dependability of five satellite precipitation products (TRMM [Tropical Rainfall Measuring Mission] 3BV42, PERSIANN [Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks] CDR, GSMaP [Global Satellite Mapping of Precipitation] RENALYSIS, CMORPH [Climate Prediction Center’s morphing technique] BLD and CMORPH_RAW were compared with in situ measurements over China for the period of 2005 to 2013. To completely evaluate these precipitation products, the annual, seasonal and monthly precipitation averages were calculated. Overall, the Huaihe River and Qinlin mountains are shown to have heavy precipitation to the southeast and lighter precipitation to the northwest. The comparison results indicate that Gauge correction (CMORPH_BLD improves the quality of the original satellite products (CMORPH_RAW, resulting in the higher correlation coefficient (CC, the low relative bias (BIAS and root mean square error (RMSE. Over China, the GSMaP_RENALYSIS outperforms other products and shows the highest CC (0.91 and lowest RMSE (0.85 mm/day and all products except for PERSIANN_CDR exhibit underestimation. GSMaP_RENALYSIS gives the highest of probability of detection (81%, critical success index (63% and lowest false alarm ratio (36% while TRMM3BV42 gives the highest of frequency bias index (1.00. Over Tibetan Plateau, CMORPH_RAW demonstrates the poorest performance with the biggest BIAS (4.2 mm/month and lowest CC (0.22 in December 2013. GSMaP_RENALYSIS displays quite consistent with in situ measurements in summer. However, GSMaP_RENALYSIS and CMORPH_RAW underestimate precipitation over South China. CMORPH_BLD and TRMM3BV42 show consistent with high CC (>0.8 but relatively large RMSE in summer.

Current re-vegetation patterns and restoration issues in degraded geological phosphorus-rich mountain areas: A synthetic analysis of Central Yunnan, SW China

Directory of Open Access Journals (Sweden)

Kai Yan

2017-06-01

Full Text Available China has the largest area of inland geological phosphorus-rich (GPR mountains in the world, where vegetation restoration is key to safeguarding the environment. We reviewed the published literature and collected new data in order to analyze re-vegetation patterns and the status of plant communities in central Yunnan. The aim of our analysis was to suggest future improvements to restoration strategies in GPR mountain regions. Our results showed that spontaneous recovery was the most widespread type of restoration. N-fixing species such as Coriaria nepalensis and Alnus nepalensis play a vital role in succession. In the past, monoculture tree plantation was the primary method used in afforestation activities in central Yunnan; in recent years however, several different methods of restoration have been introduced including the use of agroforestry systems. For practical restoration, we found that spontaneous recovery was capable of delivering the best results, but that during its early stages, restoration results were affected by several factors including erosion risk, the origin of propagates and environmental variation. In contrast, methods employing human-made communities performed better in their early stages, but were constrained by higher costs and vulnerability to degradation and erosion. The use of N-fixing species such as A. nepalensis and Acacia mearnsii in plantations were unsuccessful in restoring full ecosystem functions. The success of restoration activities in GPR mountain regions could be improved through the following measures: (1 developing a better understanding of the respective advantages and disadvantages of current natural and human-engineered restoration approaches; (2 elucidating the feedback mechanism between phosphorus-rich soil and species selected for restoration, especially N-fixing species; (3 introducing market incentives aimed at encouraging specific restoration activities such as agroforestry, and improving the

Aquatic studies of Gable Mountain Pond

International Nuclear Information System (INIS)

Cushing, C.E.; Watson, D.G.

1974-12-01

Studies of the biotic and abiotic components of the Gable Mountain Pond (HAPO cooling water disposal pond) ecosystem were undertaken to determine if there was a potential problem for off-site transfer of radioactivity to man originating with the aquatic food web. Most of the 137 Cs in the pond is associated with the sediments which are probably the main source of 137 Cs for uptake by the biota. Generally, highest concentrations of 137 Cs and other radioisotopes were found in the upper two inches of sediments in the northwest end of the pond and in the deeper areas along the long-axis of the pond. Native goldfish had maximum and average 137 Cs concentrations of about 340 and 170 pCi/g dry wt, respectively. Algae, macrophytes, and detritus comprised the main food items of the goldfish, and the 137 Cs levels in the plants were usually higher than the 137 Cs concentration in the fish. The 137 Cs concentrations of wild experimental ducks restricted to Gable Mountain Pond were approximately the same as resident coots, but significantly higher than transient wild ducks. Neither the goldfish nor the waterfowl inhabiting the pond attained concentrations of 137 Cs exceeding acceptable limits. Sediment, however, could be a source of high concentrations of radioactivity or radioactive contamination concern if the concentration of radiocontaminants increased and/or the pond dries up, and the contaminated sediments become windborne. (U.S.)

Application of Telemedicine in Gansu Province of China

Science.gov (United States)

Cai, Hui; Wang, Hongjing

2016-01-01

Telemedicine has become an increasingly popular option for long-distance health care and continuing education. As information and communication technology is underdeveloped in China, telemedicine develops slowly. At present, telemedicine consultation centers are situated mainly in developed cities, such as Beijing, Shanghai, and Guangzhou. In many less developed regions, such as northwest China, the conditions or related facilities are not available for the application of a better medical service. Accordingly, the aim of this paper was to introduce the construction and application of a telemedicine consultation center in Gansu Province in the northwest of China. In addition, the function of Gansu Provincial Telemedicine Consultation Center on emergency public events was introduced. As a whole, there was a great demand for telemedicine service in the local medical institutions. In the telemedicine consultation center, the telemedicine equipments and regulations were needed to be improved. The function of telemedicine service was not fully used, there was a large space to be applied and the publicity of telemedicine service was important. What is important was that telemedicine played a significance role in promoting the medical policy reform, improving the medical environment and launching the remote rescue in the emergency public events. This paper emphasizes the health care challenges of poor regions, and indicates how to share the high-quality medical service of provincial hospitals effectively and how to help residents in resource-poor environments. PMID:27332894

Preparing to Submit a License Application for Yucca Mountain

International Nuclear Information System (INIS)

W.J. Arthur; M.D. Voegele

2005-01-01

of the United States, approximately 100 miles (160 kilometers) northwest of Las Vegas (Figure 1). The location is remote from population centers, and there are no permanent residents within approximately 14 miles (23 km) of the site. Overall, Nye County has a population density of about two persons per square mile (two persons per 2.5 square km); in the vicinity of Yucca Mountain, it is significantly less. Yucca Mountain is a series of north-south-trending ridges extending approximately 25 miles (40 km), and consists of successive layers of fine-grained volcanic tuffs, millions of years old, underlain by older carbonate rocks. The alternating layers of welded and nonwelded volcanic tuffs have differing hydrologic properties that significantly impact the manner in which water moves through the mountain. The repository horizon will be in welded tuff located in the unsaturated zone, more than 1,000 feet (300 meters) above the water table in the present-day climate, and is expected to remain well above the water table during wetter future climate conditions. Future meteorology and climatology at Yucca Mountain are important elements in understanding the amount of water available to potentially interact with the waste

Carbon balance of a plastic mulch and drip irrigated cotton field in an arid oasis of Northwest China

Science.gov (United States)

Ming, G.

2017-12-01

Carbon balance of a plastic mulch and drip irrigated cotton field in an arid oasis of Northwest ChinaGuanghui Ming1, Fuqiang Tian1*, Hongchang Hu11State Key Laboratory of Hydroscience and Engineering, Department of Hydraulic Engineering, Tsinghua University, Beijing, China,Abstracts: Agricultural ecosystems have the potential to offset rising CO2 concentration in the atmosphere but the potential is often altered by agricultural management. Plastic film mulching and drip irrigation (PMDI) have been widespread for saving water and improving crop yield worldwide. To comprehensively assess the carbon balance and to detect the controlling factors of the carbon flux in a PMDI cotton field, experiments combining eddy covariance (EC) system, chamber method and crop sampling were implemented in an arid oasis of Xinjiang from the year 2012 to 2016. The annual net ecosystem exchange (NEE) was -250.18 ± 80.41 g C m-2 in the five years, which indicated that the filed was a much stronger carbon sink. After removal of the harvest of cotton as seed oil (Ch) of 108.81±7.57 g C m-2, the field was still a moderate carbon sink with net biome productivity (NBP) of 141.37±73.7 g C m-2. Soil temperature can explain 82% of seasonal variation of nighttime NEE while PAR can explain 36-81% of daytime NEE varying with crop development and photosynthetic activity. NEE was separated into total ecosystem respiration (Reco, 1214.20±144.42 g C m-2) and gross primary productivity (GPP, 1464.38±122.78 g C m-2). Interannual Reco changed more drastically than GPP and respiration may be the main determinant of carbon balance in the PMDI field. Seasonal NPP measured by cop sampling method (NPPCS) agreed well with NPP calculated with EC (NPPEC), with the annual NPP of 708.86 ± 52.26 g C m-2, which indicated that our carbon flux measurements and separating methods reasonable. The PMDI cotton field induced more GPP and Reco than other croplands with larger light use efficiency (LUE) but relatively

Long-range atmospheric transport of persistent organochlorinated compounds from south and mainland south-eastern Asia to a remote mountain site in south-western China.

Science.gov (United States)

Xu, Yue; Zhang, Gan; Li, Jun; Chakraborty, Paromita; Li, Hua; Liu, Xiang

2011-11-01

A range of organochlorinated compounds have been consumed in China, India and the countries of mainland southeast Asia (MSA). Considering their persistence in the environment and ability in long-range atmospheric transport (LRAT), the potential outflow of these compounds from this region is therefore of great concern in the context of the global distribution of toxic chemicals. As part of a monitoring campaign aimed at investigating the LRAT of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) from southern China, MSA and northern India, atmospheric levels of OCPs and PCBs were measured once a week from October 2005 through December 2006 at Tengchong Mountain (TM), a remote site located in south-western China. The average concentrations of OCPs were found to be higher than those in other remote stations in the Arctic and the Tibetan plateau, except for α-hexachlorocyclohexane (α-HCH). A high level of β-HCH and low α-HCH/β-HCH ratio was attributed to an accidental release of β-HCH from unknown sources, besides obvious evidence of lindane (γ-HCH) and technical HCH usage. Temporal variations of chlordanes and endosulfan were related to the usage pattern of these compounds, as well as LRAT. In contrast, dichlorodiphenyltrichloroethane (DDT) exhibited a relatively minor seasonal variation. The OCP levels at the monitoring site were found to be related to the air parcel back trajectories on the basis of four distinct clusters. Elevated levels of HCHs and DDTs were observed when air parcels originated from northern India where considerable OCP usage was reported recently, while high levels of γ-HCH and TC (trans-chlordane) were mainly associated with air masses from southern China and northern MSA. The study highlighted the high background level of OCPs as well as their temporal patterns of trans-boundary LRAT in the MSA region.

Rhododendron aureum Georgi formed a special soil microbial community and competed with above-ground plants on the tundra of the Changbai Mountain, China.

Science.gov (United States)

Wang, Xiaolong; Li, Lin; Zhao, Wei; Zhao, Jiaxin; Chen, Xia

2017-09-01

Rhododendron aureum Georgi is a perennial evergreen dwarf shrub that grows at all elevations within the alpine tundra of northern China. Previous research has investigated the plant communities of R. aureum ; however, little information is available regarding interspecific competition and underground soil microbial community composition. The objective of our study was to determine whether the presence of R. aureum creates a unique soil microbiome and to investigate the relationship between R. aureum and other plant species. Our study site ranged from 1,800 to 2,600 m above sea level on the northern slope of the Changbai Mountain. The results show that the soil from sites with an R. aureum community had a higher abundance of nitrogen-fixing bacteria and a higher resistance to pathogens than soils from sites without R. aureum . We emphasize that R. aureum promotes a unique soil microbial community structure that is distinct from those associated with other plants. Elevation and microbial biomass were the main influencing factors for plant community structure. Analysis of interspecific relationships reveals that R. aureum is negatively associated with most other dominant shrubs and herbs, suggesting interspecific competition. It is necessary to focus on other dominant species if protection and restoration of the R. aureum competition is to occur. In the future, more is needed to prove whether R. aureum decreases species diversity in the tundra ecosystems of Changbai Mountain.

1991 Pacific Northwest loads and resources study, Pacific Northwest economic and electricity use forecast

International Nuclear Information System (INIS)

1992-01-01

This publication provides detailed documentation of the load forecast scenarios and assumptions used in preparing BPA's 1991 Pacific Northwest Loads and Resources Study (the Study). This is one of two technical appendices to the Study; the other appendix details the utility-specific loads and resources used in the Study. The load forecasts and assumption were developed jointly by Bonneville Power Administration (BPA) and Northwest Power Planning Council (Council) staff. This forecast is also used in the Council's 1991 Northwest Conservation and Electric Power Plan (1991 Plan)

Reconstruction of March-June precipitation from tree rings in central Liaoning, China

Science.gov (United States)

Wang, Yanchao; Liu, Yu

2017-11-01

A dendrochronological profile was generated from Chinese pines ( Pinus tabulaeformis Carr.) in the Qianshan Mountains in northeastern China. Based on correlation analyses, the pattern of precipitation from March to June ( P 36 ) was reconstructed using a simple linear model, which explained 42.7% of the total variance in observed precipitation from 1951 to 2012. The reconstructed P 36 series revealed a consistently increasing trend in precipitation during the twentieth century in the Qianshan Mountains. The reconstructed data showed trends that were similar to those in the variation in trends for March-June precipitation observed at the Shenyang station, the reconstructed January-May precipitation trends in Shenyang City, and the reconstructed average June-September relative humidity for Yiwulü Mountain. The reconstructed data also showed good agreement with the droughts reported in historical documents and recorded by meteorological stations in Liaoning. Spatial correlation analyses show that the reconstructed data reflect the variability in precipitation that occurs over much of northeastern China. In addition, our reconstruction showed a significant periodicity. The significant correlations between the reconstructed P 36 and the El Niño-Southern Oscillation (ENSO), Pacific Decadal Oscillation (PDO) and sunspot numbers indicate that precipitation variability in the Qianshan Mountain region is probably driven by extensive atmosphere-sea interactions and solar activities.

Research progress of socio-economic water cycle in China

Institute of Scientific and Technical Information of China (English)

无

2002-01-01

China has made great progress in the study of socio-economic water cycle. She has completed national water resources appraisement and medium to long-term water supply planning. She has been engaging in study on water-deficient regions in North China and Northwest China for about half a century. For solving water shortage problem in northern China, she has put forward the famous South-to-North Water Transferring Projects, which has been set as one of the four biggest national projects in the Tenth Five-Year-Plan period although there are still debates. For promoting water use efficiency, China has been reforming her water management system, including water right system and water price system. There has already been a case of water right purchase. China has also done a lot of research on the interaction between human activity, water and ecosystem. For meeting the need of sustainability and coordinating water resources development and environmental protection, the study of ecological water requirement became very hot in recent years. There are three focuses of socio-economic water cycle study now in China: water transfer projects from the south to the north, water resources management and ecological water requirement.

Loess deposits since early Pleistocene in northeast China and implications for desert evolution in east China

Science.gov (United States)

Sun, Miao; Zhang, Xujiao; Tian, Mingzhong; Liu, Ru; He, Zexin; Qi, Lin; Qiao, Yansong

2018-04-01

Loess deposits and deserts are regarded as coupled geological systems and loess deposits on the periphery of deserts can often be used to reconstruct desert evolution. Previous studies of desert evolution in Asia are mainly concentrated in northwest China and the China Loess Plateau, and little is known about long-term desert evolution in east China. In this study, we selected the Sishijiazi loess section in the Chifeng area in northeast China to study the long-term evolution of the desert in east China. A high-resolution magnetostratigraphy combined with optically stimulated luminescence dating indicated that the age of the section base is approximately 1.02 Ma. The Brunhes-Matuyama boundary is at the depth of 39.8 m in loess unit L8, and the upper boundary of the Jaramillo Subchron is at the depth of 60.8 m in paleosol S10. The results of grain-size analysis indicate a coarsening grain-size trend in the past 1.0 Ma. In addition, based on grain-size variations, the desert evolution in east China since ∼1.0 Ma can be divided into three stages: stability from 1.0 to 0.8 Ma, desert recession from 0.8 to 0.5 Ma, and gradual expansion since 0.5 Ma. Our results further indicate that the evolution of desert in east China was mainly controlled by changes in global ice volume, and that the uplift of the Tibetan Plateau may have had an additional effect.

CASE STUDY: China — Bridging the Gap between Scientists and ...

International Development Research Centre (IDRC) Digital Library (Canada)

2011-01-05

Jan 5, 2011 ... CASE STUDY: China — Bridging the Gap between Scientists and ... the right inputs of water, fertilizer, and pesticides to maximize yields. ... Some are rare and unique to the area, such as black wax maize and mountain lily.

Bedrock geologic Map of the Central Block Area, Yucca Mountain, Nye County, Nevada

International Nuclear Information System (INIS)

W.C. Day; C. Potter; D. Sweetkind; R.P. Dickerson; C.A. San Juan

1998-01-01

Bedrock geologic maps form the foundation for investigations that characterize and assess the viability of the potential high-level radioactive waste repository at Yucca Mountain, Nevada. As such, this map focuses on the central block at Yucca Mountain, which contains the potential repository site. The central block is a structural block of Tertiary volcanic rocks bound on the west by the Solitario Canyon Fault, on the east by the Bow Ridge Fault, to the north by the northwest-striking Drill Hole Wash Fault, and on the south by Abandoned Wash. Earlier reconnaissance mapping by Lipman and McKay (1965) provided an overview of the structural setting of Yucca Mountain and formed the foundation for selecting Yucca Mountain as a site for further investigation. They delineated the main block-bounding faults and some of the intrablock faults and outlined the zoned compositional nature of the tuff units that underlie Yucca Mountain. Scott and Bonk (1984) provided a detailed reconnaissance geologic map of favorable area at Yucca Mountain in which to conduct further site-characterization studies. Of their many contributions, they presented a detailed stratigraphy for the volcanic units, defined several other block-bounding faults, and outlined numerous intrablock faults. This study was funded by the U.S. Department of Energy Yucca Mountain Project to provide a detailed (1:6,000-scale) bedrock geologic map for the area within and adjacent to the potential repository area at Yucca Mountain, Nye County, Nevada. Prior to this study, the 1:12,000-scale map of Scott and Bonk (1984) was the primary source of bedrock geologic data for the Yucca Mountain Project. However, targeted detailed mapping within the central block at Yucca Mountain revealed structural complexities along some of the intrablock faults that were not evident at 1:12,000 (Scott and Bonk, 1984). As a result, this study was undertaken to define the character and extent of the dominant structural features in the

Distinguishing between anthropogenic and climatic impacts on lake size: a modeling approach using data from Ebinur Lake in arid northwest China

Directory of Open Access Journals (Sweden)

Long Ma

2014-03-01

Full Text Available Evaluation of anthropogenic and climatic impacts on lake size variation is important for maintaining ecosystem integrity and sustaining societal development. We assumed that climate and human activity are the only drivers of lake-size variation and are independent of each other. We then evaluated anthropogenic and climatic effects on hydrological processes, using a multivariate linear model. Macro-economic data were used to describe the anthropogenic impact on lake surface area in our approach. Ebinur Lake is a shallow, closed, saline lake in arid northwest China; it has shrunk at a rapid rate over the past half century. Using our new method, we explored temporal trends of anthropogenic and climatic impacts on the lake over the past 50 years. Assessment indices indicate that the model represents observed data quite well. Compared with the reference period of 1955-1960, impacts of climate change across the catchment were generally positive with respect to lake area, except for the period from 1961 to 1970. Human activity was responsible for a reduction in lake surface area of 286.8 km2 over the last 50 years. Our approach, which uses economic variables to describe the anthropogenic impact on lake surface area, enables us to explain the lake responses to climate change and human activities quantitatively.

Techno-Orientalism with Chinese Characteristics: Maureen F. McHugh’s China Mountain Zhang

Directory of Open Access Journals (Sweden)

Christopher T. Fan

2015-03-01

Full Text Available Christopher T. Fan argues that McHugh’s award-winning 1992 science fiction novel perceives the twilight of the American Century by offering a “critical realism,” to use Georg Lukács’s phrase, of postsocialist US–China interdependency. In other words, it offers a form in which we perceive ourselves as subjects and objects of the twenty-first century world-system’s most important bilateral relationship. Moreover, as a novel about US–China interdependency, it implicitly critiques the binary Orientalism that structures the rapidly growing body of work on “techno-Orientalist” formations. Fan's analysis thus extends arguments about American Orientalism’s non-Manichean formations (Christina Klein, Melani McAlister, Colleen Lye into the postsocialist era.The novel’s near-future, China-centric world analogizes McHugh’s personal crises of professional desire as a precarious laborer in New York City, with the massive reorientation of desires from Maoist politics to market-directed individuality that she witnessed among her students when she taught in China from 1987–1988. Chinese racial form plays a crucial mediating role in the novel because it reflects the revival of Confucian humanist discourse in reform-era China as a way to focus a national project of rapidly generating capitalist desire. Finally, by describing US–China interdependency, this article also generates a theory of US–China neoliberalism that corrects for universalist, Euro-American accounts of neoliberal subject formation (Lauren Berlant, as well as insufficiently subject-sensitive accounts (Aihwa Ong.

Development of Education Programs in Mountainous Regions to Enhance the Culture and Knowledge of Minority Nationalities.

Science.gov (United States)

Wei, Shiyuan; Zhou, Guangda

1989-01-01

Describes the historical development of educational programs which could enhance the culture and knowledge of minorities in the mountainous regions of China. Identifies current major problems in minority education and lists statistical information for the school population. Provides guidelines for developing a minority education program. (KO)

Ecosystem Services and Related Sustainable Management of River Oases along the Tarim River in Northwest China

Science.gov (United States)

Disse, M.; Keilholz, P.; Rumbaur, C.; Thevs, N.

2011-12-01

Within the Taklimakan Desert of Northwestern China, an area renowned for its extreme climate and vulnerable ecosystems, lies one of the largest inland rivers in the world, the Tarim River. Because the Tarim River is located in a remote area from the oceans, rainfall is extremely rare (less than 50 mm per year) but potential evaporation is high (3000 mm). Thus, the major source of water discharge comes from snowmelt and glacier-melt in the mountains. Though the water discharge into the Tarim River has experienced an increase over the past ten years, global climate change forecasts predict this water supply to decline within the century. The Tarim River is the major source of water in Northwestern China, and has become the hub of many economic activities related to agriculture and urban life. Over the past 50 years increased activity in the area has led to a severe decline in river flow. Both human and natural ecosystems have been impacted by water diversions. Since rainfall is rare, the majority of vegetation in this area depends solely on groundwater for survival, and plants are experiencing stress caused by decreasing groundwater levels. Recently nearby cities have experienced severe dust storms caused by the shrinking of the vegetative region along the river. SuMaRiO (Sustainable Management of River Oases) is a bundle project between Germany and China working to contribute to a sustainable land management which explicitly takes into account ecosystem functions (ESF) and ecosystem services (ESS). In a transdisciplinary research process, SuMaRiO will identify realizable management strategies, considering social, economic and ecological criteria. SuMaRiO is developing tools to work with Chinese decision makers to implement sustainable land management strategies. In addition, research is being conducted to estimate climate change impacts, floodplain biodiversity, and water runoff characteristics. The overarching goal of SuMaRiO is to support oasis management along

Impacts of Spatial Climatic Representation on Hydrological Model Calibration and Prediction Uncertainty: A Mountainous Catchment of Three Gorges Reservoir Region, China

Directory of Open Access Journals (Sweden)

Yan Li

2016-02-01

Full Text Available Sparse climatic observations represent a major challenge for hydrological modeling of mountain catchments with implications for decision-making in water resources management. Employing elevation bands in the Soil and Water Assessment Tool-Sequential Uncertainty Fitting (SWAT2012-SUFI2 model enabled representation of precipitation and temperature variation with altitude in the Daning river catchment (Three Gorges Reservoir Region, China where meteorological inputs are limited in spatial extent and are derived from observations from relatively low lying locations. Inclusion of elevation bands produced better model performance for 1987–1993 with the Nash–Sutcliffe efficiency (NSE increasing by at least 0.11 prior to calibration. During calibration prediction uncertainty was greatly reduced. With similar R-factors from the earlier calibration iterations, a further 11% of observations were included within the 95% prediction uncertainty (95PPU compared to the model without elevation bands. For behavioral simulations defined in SWAT calibration using a NSE threshold of 0.3, an additional 3.9% of observations were within the 95PPU while the uncertainty reduced by 7.6% in the model with elevation bands. The calibrated model with elevation bands reproduced observed river discharges with the performance in the calibration period changing to “very good” from “poor” without elevation bands. The output uncertainty of calibrated model with elevation bands was satisfactory, having 85% of flow observations included within the 95PPU. These results clearly demonstrate the requirement to account for orographic effects on precipitation and temperature in hydrological models of mountainous catchments.

Genetic analysis of Asian longhorned beetle populations from Chicago, New York, and China using the RAPD technique

Science.gov (United States)

James M. Slavicek; Patricia De Graff

2003-01-01

Anoplophora glabripennis samples were collected in the Ravenswood area of Chicago, near the Mt. Zion cemetery in Queens, New York (provided by Leah Bauer) and the Gansu Province in northwest China (provided by Leah Bauer).

Assessment and the levels of radioactivity of natural radionuclides in drinking waters in China

International Nuclear Information System (INIS)

Liu Yulan

1989-03-01

In order to assess the levels of radioactivity of natural radionuclides in drinking waters and to estimate the internal doses of the population of China from ingestion, 1650 samples of waters were collected from normal radiation background areas of 28 provinces or autonomous regions of China. Radioactivity levels of U, Th, 226 Ra and 40 K in drinking waters were determined. The levels and the characteristics of distribution of 4 radionuclides are given. The results show that radioactivity levels in the southeast China are lower than in the north and northwest China. The average radioactivity levles of the 4 radionuclides in China close to the average levels given in UNSCEAR 1986 report. The result of estimation of internal doses from ingestion in the population of China is below the corresponding results given in UNSCEAR 1986 report, but near the result given by ICRP

Control of Eospalax baileyi (Plateau Zokor) with arrow traps in western China

NARCIS (Netherlands)

Kong, Yang; Xidong, Li; Gaowei, Xu; Wei, Liu; Meerburg, B.G.

2016-01-01

In order to manage Eospalax (Myospalax) baileyi (Plateau zokors) pests with physical method, the efficacy of four different arrow traps was tested to control the plateau zokor in Sichuan Northwest Prairie, China. Population densities of 39.7-42.1 ha-1 were found in the test plots. Such densities

Climate Change Impacts on the Potential Distribution of Eogystia hippophaecolus in China.

Science.gov (United States)

Li, Xue; Ge, Xuezhen; Chen, Linghong; Zhang, Linjing; Wang, Tao; Shixiang, Zong

2018-05-28

Seabuckthorn carpenter moth, Eogystia hippophaecolus (Hua, Chou, Fang, & Chen, 1990), is the most important boring pest of sea buckthorn (Hippophae rhamnoides L.) in the northwest of China. It is responsible for the death of large areas of H. rhamnoides forest, seriously affecting the ecological environment and economic development in northwestern China. To clarify the potential distribution of E. hippophaecolus in China, the present study used the CLIMEX 4.0.0 model to project the potential distribution of the pest using historical climate data (1981-2010) and simulated future climate data (2011-2100) for China. Under historical climate condition, E. hippophaecolus would be found to be distributed mainly between 27° N - 51° N and 74° E - 134° E, with favorable and highly favorable habitats accounting for 35.2% of the total potential distribution. Under future climate conditions, E. hippophaecolus would be distributed mainly between 27° N - 53° N and 74° E - 134° E, with the possibility of moving in a northwest direction. Under these conditions, the proportion of the total area providing a favorable and highly favorable habitat may decrease to about 33%. These results will help to identify the impact of climate change on the potential distribution of E. hippophaecolus, thereby providing a theoretical basis for monitoring and early forecasting of pest outbreaks. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Analysis on the Changing Spatial Patterns of China's Migration in 1985-2010

Science.gov (United States)

Zan, Q.; Bian, Y.

2014-11-01

Based on the data of China's fourth, fifth and sixth population census, taking the seven geographical zone as research units, the Changing Spatial Patterns of China's Migration in 1985-2010 is studied by the means of spatial analysis and mathematical statistics. The empirical results show that: (1) The migration population in China was increasing a lot in 1985-2010, and the main part of it is Provincial migration. (2) The total number of migration, immigration and emigration, the relative proportion of inter provincial and provincial migration have been positively correlated to the regional economic development level. (3) The emigrations from Hong Kong, Macao, Taiwan and overseas mainly moved to East and North China. (4) Central and west of China are the main area where people outflowed from, and most migration population moved to south-eastern coastal areas. The migration in Northeast and northwest of China is still relatively small. The main direction of population migration and flowing is from west to east and from north to south.

Selected hydrologic data from Fortymile Wash in the Yucca Mountain area, Nevada, water years 1993--94

Energy Technology Data Exchange (ETDEWEB)

Savard, C.S.

1996-09-01

The Yucca Mountain area is being evaluated by the US Department of Energy for its suitability to store high-level nuclear waste in a mined, underground repository. Hydrologic data are being collected by the US Geological Survey throughout a 150 Km{sup 2} study area about 15- Km northwest of Las Vegas in southern Nevada for site characterization studies. Ongoing hydrologic studies are investigating atmospheric precipitation, stream-flow, movement of water through the unsaturated zone, movement of water through the saturated zone, and paleohydrology. This study at Fortymile Wash involves some components of each of these studies. Fortymile Wash is an ephemeral stream near Yucca Mountain with tributaries draining the east side of Yucca Mountain and then forming a distributary system in the Amargosa Desert. An objective of the study is to determine the amount of recharge from Fortymile Wash to the ground-water flow system that has been proposed. Understanding the ground-water flow system is important because it is a possible mechanism for radionuclide migration from the repository to the accessible environment. An adequate understanding of the ground-water flow system is necessary for an evaluation of the safety issues involved in siting the potential repository.

Late Eocene white pines (Pinus subgenus Strobus) from southern China.

Science.gov (United States)

Xu, Qingqing; Zhou, Wenjun; Kodrul, Tatiana M; Naugolnykh, Serge V; Jin, Jianhua

2015-11-09

Fossil records indicate that the genus Pinus L. split into two subgenera by the Late Cretaceous, although subgenus Strobus (D. Don) Lemmon is less well documented than subgenus Pinus L., especially in eastern Asia. In this paper, Pinus maomingensis sp. nov. is established based on a compressed seed cone from the upper Eocene of the Maoming Basin of southern China. This species is attributed to genus Pinus, subgenus Strobus, section Quinquefoliae Duhamel, subsection Strobus Loudon based on the combination of morphological characters obtained from the cone scales, specifically from the terminal umbo, rhombic apophysis, and cuticle structure. Associated fascicles of needle leaves with deciduous sheaths and bulbous bases are recognized as Pinus sp. and also represent Pinus subgenus Strobus. This new discovery from the Maoming Basin constitutes the first megafossil record of subgenus Strobus from southern China and implies that the members of this subgenus arrived in the southern region of China by the late Eocene. The extant species of subgenus Strobus are mainly distributed in northern temperate and tropical to subtropical mountainous regions. We propose that the Maoming Basin was adjacent to a mountainous region during the late Eocene.

Effect of climatic change and afforestation on water yield in the Rocky Mountain Area of North China

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Yang Zhao

2015-04-01

Full Text Available Aim of study: We studied effects of climatic variability and afforestation on water yield to make a quantitative assessment of the hydrological effects of afforestation on basin water yield in the Rocky Mountain Area of North China. Area of study: Seven typical forest sub-watersheds in Chaobai River watershed, located near Beijing’s Miyun Reservoir, were selected as our study object. Material and methods: Annual water yield model and Separate evaluation method were applied to quantify the respective contributions of changes in climate and different vegetation types on variations in runoff. Main results: Statistical analysis indicated precipitation did not vary significantly whereas the annual runoff decreased significantly in the past decades. Although forest increased significantly in the late 20th century, climatic variations have the strongest contribution to the reductions in runoff, with the average contribution reaching 63.24%, while the remainder caused by human activities. Afforestation has a more positive impact on the reduction in runoff, with a contribution of 65.5%, which was more than the grassland of 17.6% and the farmland of 16.9%. Research highlights: Compared to the impact of climatic change, we believe the large-scale afforestation may not be the main reason for the reductions in basin water yield.

Topography- and Species-Dependent Climatic Responses in Radial Growth of Picea meyeri and Larix principis-rupprechtii in the Luyashan Mountains of North-Central China

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Wentao Zhang

2015-01-01

Full Text Available Dendroecological techniques were used to examine the relationships between topographic aspects, climate factors and radial growth of Picea meyeri and Larix principis-rupprechtii in Luyashan Mountains, North-Central China. Four sites were selected at timberline and totally 67 trees and 134 cores were collected. Pearson correlation and regression surface analysis were conducted to reveal the growth-climate relationships. The results indicated that the two species both showed significant negative correlations with temperature during preceding November on the two topographic aspects. On both slope aspects, growth of P. meyeri exhibited significant negative correlations with precipitation in current June, whereas growth of L. principis-rupprechtii showed significant negative correlations with precipitation in preceding September. On north-facing slope, tree growth was limited by low temperature in early growing season, which not shown on south-facing slope. If climate warming continues, L. principis-rupprechtii may be more favored and a reverse between relationships with temperature and precipitation maybe occur in growth of trees. Treeline position on the north-facing slope may possess a greater potential for elevation shifting than the south-facing slope. Our results supply useful information for discussing the potential effect of future climate on the forest growth in North-Central China.

Multiscale Spatio-Temporal Dynamics of Economic Development in an Interprovincial Boundary Region: Junction Area of Tibetan Plateau, Hengduan Mountain, Yungui Plateau and Sichuan Basin, Southwestern China Case

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Jifei Zhang

2016-02-01

Full Text Available An interprovincial boundary region is a new subject of economic disparity study in China. This study explored the multi-scale spatio-temporal dynamics of economic development from 1995 to 2010 in the interprovincial boundary region of Sichuan-Yunnan-Guizhou, a mountain area and also the junction area of Tibetan Plateau, Hengduan Mountain, Yungui Plateau and Sichuan Basin in southwestern China. A quantitative study on county GDP per capita for different scales of administrative regions was conducted using the Theil index, Markov chains, a geographic information system and exploratory spatial data analysis. Results indicated that the economic disparity was closely related with geographical unit scale in the study area: the smaller the unit, the bigger the disparity, and the regional inequality gradually weakened over time. Moreover, significant positive spatial autocorrelation and clustering of economic development were also found. The spatial pattern of economic development presented approximate circle structure with two cores in the southwest and northeast. The Panxi region in the southwest core and a part of Hilly Sichuan Basin in the northeast core were considered to be hot spots of economic development. Most areas in the east and central region were persistently trapped in the low level of a balanced development state, with a poverty trap being formed in the central and south part. Geographical conditions and location, administrative barriers and the lack of effective growth poles may be the main reasons for the entire low level of balanced development. Our findings suggest that in order to achieve a high level of balanced development, attention should be paid beyond developing transportation and other infrastructure. Breaking down the rigid shackles of administrative districts that hinder trans-provincial cooperation and promoting new regional poles in the Yunnan-Guizhou region may have great significance for the study area.

Heavy metals and polychlorinated biphenyls (PCBs) sedimentation in the Lianhua Mountain Reservoir, Pearl River Delta, China.

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Huang, Jingyu; Amuzu-Sefordzi, Basil; Li, Ming

2015-05-01

The Pearl River Delta is one of the biggest electronics manufacturing regions in the world. Due to the presence of abandoned industrial sites and the proliferation of large-scale electronics companies in the past four decades, it is therefore imperative to investigate the extent of heavy metals and polychlorinated biphenyls (PCBs) contamination in the region. Spatial and temporal distribution of heavy metals (Cr, Cu, Ni, Pb, and Zn) and PCBs (PCB28, PCB52, PCB101, PCB118, PCB138, PCB153, and PCB180) in the Lianhua Mountain reservoir in the Pearl River Delta, Dongguan City, China were examined based on a sedimentary profile analysis. Higher concentrations of the heavy metals detected were recorded in bottom sediments whereas 70% of the detected PCBs recorded maximum concentrations in top sediments. The geo-accumulation indices (Igeo) indicate that the study area is uncontaminated to moderately contaminated. Also, the integrated pollution indices (IPI) were above 1, except Pb, which shows that the study area is contaminated with heavy metals from anthropogenic sources. The concentrations of individual heavy metals and PCBs over a period of 60 years were also analyzed in order to establish a historical trend of pollution in the study area. This study provides baseline information on the level and historical trend of heavy metals and PCBs pollution in the study area.

Global warming: A Northwest perspective

Energy Technology Data Exchange (ETDEWEB)

Scott, M.J.; Counts, C.A. (eds.)

1990-02-01

The Northwest Power Planning Council convened a symposium in Olympia, Washington, on the subject of global climate change ( the greenhouse effect'') and its potential for affecting the Pacific Northwest. The symposium was organized in response to a need by the Power Council to understand global climate change and its potential impacts on resource planning and fish and wildlife planning for the region, as well as a need to understand national policy developing toward climate change and the Pacific Northwest's role in it. 40 figs., 15 tabs.

Phylogeographic study of Apodemus ilex (Rodentia: Muridae in Southwest China.

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Qi Liu

Full Text Available BACKGROUND: The Mountains of southwest China have complex river systems and a profoundly complex topography and are among the most important biodiversity hotspots in the world. However, only a few studies have shed light on how the mountains and river valleys promote genetic diversity. Apodemus ilex is a fine model for investigating this subject. METHODOLOGY/PRINCIPAL FINDINGS: To assess the genetic diversity and biogeographic patterns of Apodemus ilex, the complete cytochrome b gene sequences (1,140 bp were determined from 203 samples of A. draco/ilex that were collected from southwest China. The results obtained suggested that A. ilex and A. draco are sistergroups and diverged from each other approximately 2.25 million years ago. A. ilex could be divided into Eastern and Western phylogroups, each containing two sub-groups and being widespread in different geographical regions of the southern Hengduan Mountains and the western Yunnan - Guizhou Plateau. The population expansions of A. ilex were roughly from 0.089 Mya to 0.023 Mya. CONCLUSIONS: Our result suggested that A. ilex is a valid species rather than synonym of A. draco. As a middle-high elevation inhabitant, the phylogenetic pattern of A. ilex was strongly related to the complex geographical structures in southwest China, particularly the existence of deep river valley systems, such as the Mekong and Salween rivers. Also, it appears that the evolutionary history of A. ilex, such as lineage divergences and population expansions were strongly affected by climate fluctuation in the Late Pleistocene.

Family Sources of Educational Gender Inequality in Rural China: A Critical Assessment

Science.gov (United States)

Hannum, Emily; Kong, Peggy; Zhang, Yuping

2009-01-01

In this paper, we investigate the gender gap in education in rural northwest China. We first discuss parental perceptions of abilities and appropriate roles for girls and boys; parental concerns about old-age support; and parental perceptions of different labor market outcomes for girls' and boys' education. We then investigate gender disparities…

Development of a geoscience database for preselecting China's high level radioactive waste disposal sites

International Nuclear Information System (INIS)

Li Jun; Fan Ai; Huang Shutao; Wang Ju

1998-01-01

Taking the development of a geoscience database for China's high level waste disposal sites: Yumen Town, Gansu Province, northwest of China, as an example, the author introduces in detail the application of Geographical Information System (GIS) to high level waste disposal and analyses its application prospect in other fields. The development of GIS provides brand-new thinking for administrators and technicians at all levels. At the same time, the author also introduces the administration of maps and materials by using Geographical Information System

Establishment of nature reserves in administrative regions of mainland China.

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Ziliang Guo

Full Text Available Nature reserves are widely considered as one available strategy for protecting biodiversity, which is threatened by habitat fragmentation, and wildlife extinction. The Chinese government has established a goal of protecting 15% of its land area by 2015. We quantitated the characteristics and distribution of nature reserves in mainland China and evaluated the expansion process for national nature reserves. National nature reserves occupy 64.15% of the total area of nature reserves. Steppe and meadow ecosystem, ocean and seacoast ecosystem, and wild plant nature reserves represent lower percentages, particularly in national nature reserves, in which they comprised 0.76%, 0.54%, and 0.69%, respectively, of the area. Furthermore, medium and small nature reserves compose 92.32% of all nature reserves. The land area under any legal protection has reached 14.80%, although only 9.78% is strictly protected. However, if 9 super-large national nature reserves, located in Southwest and Northwest China were removed, the percentage of strictly protected area decreases to 2.66% of the land area of China. The areas contained in nature reserves in each province are not proportional to the areas of the provinces, particularly for national nature reserves, with higher protection rates in Southwest and Northwest China than in other regions. Of the 31 provinces, 22 provinces feature strict protection of less than 4% of their areas by national nature reserves; these provinces are mainly located in East, Central, South, and North China. Moreover, the unevenness indexes of the distribution of nature reserves and national nature reserves are 0.39 and 0.58, respectively. The construction of nature reserves has entered a steady development stage after a period of rapid expansion in mainland China. In recent years, the total area of national nature reserves has increased slowly, while the total area of nature reserves has not increased, although the number of nature

The Last Frontier: Catch Records of White Sharks (Carcharodon carcharias) in the Northwest Pacific Ocean

Science.gov (United States)

Christiansen, Heather M.; Lin, Victor; Tanaka, Sho; Velikanov, Anatoly; Mollet, Henry F.; Wintner, Sabine P.; Fordham, Sonja V.; Fisk, Aaron T.; Hussey, Nigel E.

2014-01-01

White sharks are highly migratory apex predators, globally distributed in temperate, sub-tropical, and tropical waters. Knowledge of white shark biology and ecology has increased recently based on research at known aggregation sites in the Indian, Atlantic, and Northeast Pacific Oceans; however, few data are available for the Northwest Pacific Ocean. This study provides a meta-analysis of 240 observations of white sharks from the Northwest Pacific Ocean between 1951 and 2012. Records comprise reports of bycatch in commercial fisheries, media accounts, personal communications, and documentation of shark-human interactions from Russia (n = 8), Republic of Korea (22), Japan (129), China (32), Taiwan (45), Philippines (1) and Vietnam (3). Observations occurred in all months, excluding October-January in the north (Russia and Republic of Korea) and July-August in the south (China, Taiwan, Philippines, and Vietnam). Population trend analysis indicated that the relative abundance of white sharks in the region has remained relatively stable, but parameterization of a 75% increase in observer effort found evidence of a minor decline since 2002. Reliably measured sharks ranged from 126–602 cm total length (TL) and 16–2530 kg total weight. The largest shark in this study (602 cm TL) represents the largest measured shark on record worldwide. For all countries combined the sex ratio was non-significantly biased towards females (1∶1.1; n = 113). Of 60 females examined, 11 were confirmed pregnant ranging from the beginning stages of pregnancy (egg cases) to near term (140 cm TL embryos). On average, 6.0±2.2 embryos were found per litter (maximum of 10) and gestation period was estimated to be 20 months. These observations confirm that white sharks are present in the Northwest Pacific Ocean year-round. While acknowledging the difficulties of studying little known populations of a naturally low abundance species, these results highlight the need for dedicated

The last frontier: catch records of white sharks (Carcharodon carcharias in the Northwest Pacific Ocean.

Directory of Open Access Journals (Sweden)

Heather M Christiansen

Full Text Available White sharks are highly migratory apex predators, globally distributed in temperate, sub-tropical, and tropical waters. Knowledge of white shark biology and ecology has increased recently based on research at known aggregation sites in the Indian, Atlantic, and Northeast Pacific Oceans; however, few data are available for the Northwest Pacific Ocean. This study provides a meta-analysis of 240 observations of white sharks from the Northwest Pacific Ocean between 1951 and 2012. Records comprise reports of bycatch in commercial fisheries, media accounts, personal communications, and documentation of shark-human interactions from Russia (n = 8, Republic of Korea (22, Japan (129, China (32, Taiwan (45, Philippines (1 and Vietnam (3. Observations occurred in all months, excluding October-January in the north (Russia and Republic of Korea and July-August in the south (China, Taiwan, Philippines, and Vietnam. Population trend analysis indicated that the relative abundance of white sharks in the region has remained relatively stable, but parameterization of a 75% increase in observer effort found evidence of a minor decline since 2002. Reliably measured sharks ranged from 126-602 cm total length (TL and 16-2530 kg total weight. The largest shark in this study (602 cm TL represents the largest measured shark on record worldwide. For all countries combined the sex ratio was non-significantly biased towards females (1∶1.1; n = 113. Of 60 females examined, 11 were confirmed pregnant ranging from the beginning stages of pregnancy (egg cases to near term (140 cm TL embryos. On average, 6.0±2.2 embryos were found per litter (maximum of 10 and gestation period was estimated to be 20 months. These observations confirm that white sharks are present in the Northwest Pacific Ocean year-round. While acknowledging the difficulties of studying little known populations of a naturally low abundance species, these results highlight the need for dedicated

The last frontier: catch records of white sharks (Carcharodon carcharias) in the Northwest Pacific Ocean.

Science.gov (United States)

Christiansen, Heather M; Lin, Victor; Tanaka, Sho; Velikanov, Anatoly; Mollet, Henry F; Wintner, Sabine P; Fordham, Sonja V; Fisk, Aaron T; Hussey, Nigel E

2014-01-01

White sharks are highly migratory apex predators, globally distributed in temperate, sub-tropical, and tropical waters. Knowledge of white shark biology and ecology has increased recently based on research at known aggregation sites in the Indian, Atlantic, and Northeast Pacific Oceans; however, few data are available for the Northwest Pacific Ocean. This study provides a meta-analysis of 240 observations of white sharks from the Northwest Pacific Ocean between 1951 and 2012. Records comprise reports of bycatch in commercial fisheries, media accounts, personal communications, and documentation of shark-human interactions from Russia (n = 8), Republic of Korea (22), Japan (129), China (32), Taiwan (45), Philippines (1) and Vietnam (3). Observations occurred in all months, excluding October-January in the north (Russia and Republic of Korea) and July-August in the south (China, Taiwan, Philippines, and Vietnam). Population trend analysis indicated that the relative abundance of white sharks in the region has remained relatively stable, but parameterization of a 75% increase in observer effort found evidence of a minor decline since 2002. Reliably measured sharks ranged from 126-602 cm total length (TL) and 16-2530 kg total weight. The largest shark in this study (602 cm TL) represents the largest measured shark on record worldwide. For all countries combined the sex ratio was non-significantly biased towards females (1∶1.1; n = 113). Of 60 females examined, 11 were confirmed pregnant ranging from the beginning stages of pregnancy (egg cases) to near term (140 cm TL embryos). On average, 6.0±2.2 embryos were found per litter (maximum of 10) and gestation period was estimated to be 20 months. These observations confirm that white sharks are present in the Northwest Pacific Ocean year-round. While acknowledging the difficulties of studying little known populations of a naturally low abundance species, these results highlight the need for dedicated research to

[Mechanisms of grass in slope erosion control in Loess sandy soil region of Northwest China].

Science.gov (United States)

Zhao, Chun-Hong; Gao, Jian-En; Xu, Zhen

2013-01-01

By adopting the method of simulated precipitation and from the viewpoint of slope hydrodynamics, in combining with the analysis of soil resistance to erosion, a quantitative study was made on the mechanisms of grass in controlling the slope erosion in the cross area of wind-water erosion in Loess Plateau of Northwest China under different combinations of rainfall intensity and slope gradient, aimed to provide basis to reveal the mechanisms of vegetation in controlling soil erosion and to select appropriate vegetation for the soil and water conservation in Loess Plateau. The grass Astragalus adsurgens with the coverage about 40% could effectively control the slope erosion. This grass had an efficiency of more than 70% in reducing sediment, and the grass root had a greater effect than grass canopy. On bare slope and on the slopes with the grass plant or only the grass root playing effect, there existed a functional relation between the flow velocity on the slopes and the rainfall intensity and slope gradient (V = DJ(0.33 i 0.5), where V is flow velocity, D is the comprehensive coefficient which varies with different underlying surfaces, i is rainfall intensity, and J is slope gradient). Both the grass root and the grass canopy could markedly decrease the flow velocity on the slopes, and increase the slope resistance, but the effect of grass root in decreasing flow velocity was greater while the effect in increasing resistance was smaller than that of grass canopy. The effect of grass root in increasing slope resistance was mainly achieved by increasing the sediment grain resistance, while the effect of canopy was mainly achieved by increasing the slope form resistance and wave resistance. The evaluation of the soil resistance to erosion by using a conceptual model of sediment generation by overland flow indicated that the critical shear stress value of bare slope and of the slopes with the grass plant or only the grass root playing effect was 0.533, 1.672 and 0

Spatial distribution and hazard degree of soil erosion of sloping croplands in northeast China

Science.gov (United States)

Zhang, T.

2017-12-01

Soil erosion is causing damage to the sloping croplands of northeast China and threatening the food security of the nation. However, little is known about the problem in macro scale. This study aims to investigate the area, slope gradient, soil erosion rate and year limit of erosion of the sloping croplands in whole northeast China and different geomorphologic regions, soil types, watersheds and administrative divisions of it, to estimate quantitatively the necessity and urgency of soil conservation and to offer advices. Meteorological data, topography data, geomorphology data, soil data and landuse data were collected. The China Soil Loss Equation was applied. The results indicated that: (1) Total area of the sloping croplands of northeast China is 195000 km2. They mainly distributed in Changbai mountainous region, eastern Songnen plain and Daxinganling mountainous region, with dark-brown earth, black soil and brown earth as main soil types. Total area of the sloping croplands steeper than 5 degree is 31000 km2. They mainly distributed in the mountain regions, with dark-brown earth and brown earth as main soil types. (2) The soil erosion rates of 92% of the sloping croplands have exceeded the soil loss tolerance in the national standard (0.15 mm/a). These croplands need to be conserved. The A horizon depths of 66% of the sloping croplands are less than 30 cm , while the year limit of A horizon erosion of 59% of the sloping croplands are less than 100 a. These croplands need to be conserved immediately. (3) Contour farming is suitable to 84% of the sloping croplands and deserves more attention. The sloping croplands steeper than 15 degree and those located in the aeolian sandy soil and some others soil types contributed little in grain production with high hazard degrees of erosion and should be reused for other purposes, as soon as possible. (4) The Changbai mountainous region, Daxinganling mountainous region, the dark-brown earth region and the brown earth region

How do two giant panda populations adapt to their habitats in the Qinling and Qionglai Mountains, China

NARCIS (Netherlands)

Liu, Xiaoji; Wang, Tiejun; Wang, Ting; Skidmore, A.K.; Songer, M.

2015-01-01

The spatial separation of the Qinling Mountains from the western mountains has caused morphological and genetic distinctions of giant pandas. Could this separation also cause the pandas’ behavior change? In this research, we focused on the pandas’ movement pattern and selected two wild panda groups

Reconstruction and analysis of the past five centuries of streamflow on northern slopes on Tianshan Mountains in Northern Xinjiang, China

Science.gov (United States)

Yang, Yuhui; Chen, Yaning; Wang, Minzhong; Sun, Huilan

2017-07-01

We examined the changes in streamflow on the northern slopes of the Tianshan Mountains in northern Xinjiang, China, over two time scales: the past 500 years, based on dendrochronology data; and the past 50 years, based on streamflow data from hydrological stations. The method of artificial neural networks built from the data of the 50-year period was used to reconstruct the streamflow of the 500-year period. The results indicate that streamflow has undergone seven high-flow periods and four low-flow periods during the past 500 years. To identify possible transition points in the streamflow, we applied the Mann-Kendall and running T tests to the 50- and 500-year periods, respectively. During the past 500 years, streamflow has changed significantly from low to high flow about three to four times, and from high to low flow about three to five times. Over the recent 50 years, there have been three phases of variation in river runoff, and the most distinct transition of streamflow occurred in 1996.

Growing Season Stem Water Status Assessment of Qinghai Spruce through the Sap Flow and Stem Radial Variations in the Qilian Mountains of China

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Quanyan Tian

2017-12-01

Full Text Available Global climate change is likely to change precipitation patterns with consequences for tree water use and growth in semi-arid areas. However, little is known about the effects of variability in precipitation on growth- and water-related physiological processes of native trees in dry areas of northwestern China. In this study, sap flow and stem radial variability in four Qinghai spruce trees (Picea crassifolia were monitored in the Qilian Mountains, China. Tree water deficit (ΔW and basal area increment (BAI were calculated using stem radial variation; water-use efficiency (WUE was then estimated as the ratio of BAI and sap flow (Jt. The results showed that sap flow density (Js increased logarithmically with increasing ΔW when ΔW < 50 μm, and then gradually stabilized. Multiple factor generalized additive models (GAM showed that Js was closely related to all measured environmental variables except for daily mean temperature and relative air humidity. ΔW was related to the minimum daily temperature and soil water content. WUE exhibited higher values in early July. Low WUE was observed under conditions of prolonged dry weather, but it quickly increased during rainy days. WUE decreased after precipitation events due to high transpiration. We concluded that, in these semi-arid areas, precipitation is the most important controlling factor in tree growth and transpiration.

Climate and glacier change in southwestern China during the past several decades

International Nuclear Information System (INIS)

Li Zongxing; He Yuanqing; An Wenling; Zhang Wei; Wang Yan; Wang Shijin; Liu Huancai; Cao Weihong; Wang Shuxin; Du Jiankuo; Song Linlin; Catto, Norm; Theakstone, Wilfred H

2011-01-01

Glaciers are distributed in the Nyainqntanglha Mountains, Himalayas, Tanggula Mountains, Gangdise Mountains and Hengduan Mountains in Southwestern China. Daily temperature and precipitation data from 111 stations, together with the records of glacier changes, indicate that temperature patterns during 1961–2008 were consistent with warming at a statistically significant level. Seasonal warming was greatest in autumn and winter. Temperature rise showed a significant relationship with sea surface temperature in the Western Pacific, net longwave radiation flux, altitude, sunshine hours, strengthening anticyclonic circulations in summer and anomalous cyclonic circulation in winter. The increase was more apparent in higher altitude areas than in lower ones. Precipitation variations were less marked than those of temperature, generally showing weak decreasing trends during 1961–2008. Increasing trends were apparent only in spring and winter, when regional trends of precipitation increases with altitude also were evident. The strengthening Western Pacific Subtropical Highs were related to precipitation variation. Against the background of increasing temperature, especially the increasing warming with altitude, the fronts of 32 glaciers and areas of 13 glacial basins have retreated, mass losses of 10 glaciers have been considerable, glacial lakes in six regions have expanded and melt water discharge of four basins has also increased, but these glaciers and basins in our study are only a fraction of the retreating glaciers over southwestern China.

Mineral resources of the Swasey Mountain and Howell Peak Wilderness Study Areas, Millard County, Utah

Energy Technology Data Exchange (ETDEWEB)

Lindsey, D.A.; Zimbelman, D.R.; Campbell, D.L.; Duval, J.S.; Cook, K.L.; Podwysocki, M.H.; Brickey, D.W.; Yambrick, R.A.; Tuftin, S.E.

1989-01-01

The Swasey Mountain and the Howell Peak Wilderness Study Areas are underlain by an east-dipping sequence of carbonate rocks, shale, and quartzite of Cambrian age. The Sand Pass mineralized area, immediately northwest of the Swasey Mountain Wilderness Study Area, contains numerous occurrences of jasperoid, small igneous intrusions of Tertiary age, and geochemical anomalies; the mineralized area has been explored for gold. Although no identified resources of metals are known in or near the wilderness study areas, the distribution of geologic structures and stream-sediment geochemical anomalies indicates there is a moderate potential for undiscovered resources of lead, zinc, copper, molybdenum, silver, and gold. An area of moderate potential for undiscovered resources of these metals extends south and east into the Swasey Mountain Wilderness Study Area from the Sand Pass mineralized area. A second area of moderate potential for undiscovered resources of these metals extends from the southern part of the Swasey Mountain Wilderness Study Area across the western part of the Howell Peak Wilderness Study Area. Both study areas contain inferred subeconomic resources of quartzite, high-purity limestone, and sand and gravel. Both areas have moderate resource potential for high-purity limestone and dolomite. Fossils, especially trilobites, of interest to collectors are present in both areas. The potential for undiscovered resources is moderate for oil and gas and is low for geothermal energy within the study areas. There is no potential for undiscovered resources of coal.

Flash Flood Type Identification within Catchments in Beijing Mountainous Area

Science.gov (United States)

Nan, W.

2017-12-01

Flash flood is a common type of disaster in mountainous area, Flash flood with the feature of large flow rate, strong flushing force, destructive power, has periodically caused loss to life and destruction to infrastructure in mountainous area. Beijing as China's political, economic and cultural center, the disaster prevention and control work in Beijing mountainous area has always been concerned widely. According to the transport mechanism, sediment concentration and density, the flash flood type identification within catchment can provide basis for making the hazards prevention and mitigation policy. Taking Beijing as the study area, this paper extracted parameters related to catchment morphological and topography features respectively. By using Bayes discriminant, Logistic regression and Random forest, the catchments in Beijing mountainous area were divided into water floods process, fluvial sediment transport process and debris flows process. The results found that Logistic regression analysis showed the highest accuracy, with the overall accuracy of 88.2%. Bayes discriminant and Random forest had poor prediction effects. This study confirmed the ability of morphological and topography features to identify flash flood process. The circularity ratio, elongation ratio and roughness index can be used to explain the flash flood types effectively, and the Melton ratio and elevation relief ratio also did a good job during the identification, whereas the drainage density seemed not to be an issue at this level of detail. Based on the analysis of spatial patterns of flash flood types, fluvial sediment transport process and debris flow process were the dominant hazards, while the pure water flood process was much less. The catchments dominated by fluvial sediment transport process were mainly distributed in the Yan Mountain region, where the fault belts were relatively dense. The debris flow process prone to occur in the Taihang Mountain region thanks to the abundant

The first commercial spent fuel shipment in China

International Nuclear Information System (INIS)

Meinert, N.M.; Xiaoqing Li

2004-01-01

In two and a half years, government regulatory agencies and contractors from three countries worked together to design, license, fabricate, and transport the first commercial spent fuel shipment in China. Their cooperative efforts helped avoid the loss of full core reserve at a nuclear power plant serving two of China's largest cities. In March 2001, Everclean Environmental Engineering Corporation (EEEC) selected NAC International (NAC) to supply two United States Nuclear Regulatory Commission (USNRC) licensed Storable Transport Casks (NACSTC) and technology support, to ensure that qualified Chinese operators would be ready to load the first cask in late 2003. EEEC is a subsidiary of China National Nuclear Corporation (CNNC), which sets nuclear policy in China. EEEC is responsible for implementing nuclear transportation policy set forth from its parent corporation. Timely implementation of EEEC's ambitious plan would avoid loss of full core reserve at Guangdong Nuclear Power Station (Daya Bay) Unit-1, which supplies power to Hong Kong and Schenzen. The spent fuel would be transported to the Lanzhou Nuclear Fuel Complex (LNFC), a reprocessing facility, approximately 4,000 kilometers Northwest of Daya Bay

The Anaximander Mountains linkages with the Florence Rise in the east and the Pliny-Strabo Trench in the west, eastern Mediterranean

Science.gov (United States)

Barnes, Melanie; Hall, Jeremy; Aksu, Ali; Çifçi, Günay

2014-05-01

Interpretation of ~4500 km of high-resolution multichannel seismic reflection profiles and correlation with complex multibeam bathymetric features allows us to assess the Neogene tectonics of this area of the Anaximander Mountains at the junction of the Hellenic and Cyprus Arcs. Three seiusmic stratigraphic units are observed in this region and are correlated with exploration wells drilled onland in the Antalya and Kasaba Basins, and DSDP holes 375 and 376: The uppermost Unit (1, Pliocene-Quaternary) is a strongly reflective laterally continuous package of high frequency reflections which extends from the seabed to the M-reflector. Beneath this, Unit 2 (Messinian) is a weakly reflective package displaying complex internal architecture with weak, discontinuous and often chaotic reflections bounded at their top and base by the M- and N-reflectors, respectively. Unit 3 (pre-Messinian Miocene) is a strongly reverberatory, high reflective package of low amplitude reflections with significant lateral continuity. The structural architecture of the Anaximander Mountains (sensu lato) at the junction of the Hellenic and Cyprus Arcs is characterised by two phases of deformation. A protracted interval of contraction in the Miocene created a series of broadly east-west trending and predominantly south-verging structures across the entire eastern Mediterranean. This phase culminated in the latest Miocene and was followed in the Pliocene-Quaternary by an interval of spatially-partitioned strain which resulted in the development of discrete domains characterized by extensional, contractional, transpressional and transtensional structures. The Anaximenes and Anaxagoras Mountains in the east and southeast exhibit contractional/transpressional deformation and form the linkage with the Florence Rise to the southeast. An arcuate and extensively faulted and folded region immediately northwest of the Anaximenes and Anaxagoras Mountains (i.e., the Sırrı Erinç Plateau) forms a 30-40 km

Spatial patterns of 137Cs inventories and soil erosion from earth-banked terraces in the Yimeng Mountains, China

International Nuclear Information System (INIS)

Zhang, Yunqi; Long, Yi; An, Juan; Yu, Xingxiu; Wang, Xiaoli

2014-01-01

The Yimeng Mountains is one of China's most susceptible regions to soil erosion. In this region, slopes are composed of granite- or gneiss-derived soils that are commonly cultivated using earth-banked terraces. Based on the 137 Cs measurement for nine reference cores, the present study analysed the spatial patterns of 137 Cs inventory and soil erosion using 105 sampling points in a seven-level earth-banked terrace system. The mean 137 Cs inventory, standard deviation, coefficient of variation, and allowable error for the nine reference cores were 987 Bq m −2 , 71 Bq m −2 , 7%, and 6%, respectively, values that may reflect the heterogeneity of the initial 137 Cs fallout deposit. Within each terrace, the 137 Cs inventory generally increases from the rear edge to the front edge, accompanied by a decrease in the erosion rate. This results from planation by tillage and rainfall runoff during the development of the earth-banked terraces. Across the entire seven-level terrace system, 137 Cs inventories decrease from the highest terrace downwards, but increase in the lower terraces, whereas erosion rate displays the opposite trend. These trends are the result of the combined effects of the earth-bank segmented hillslope, the limited protection of the earth banks, and rainfall runoff in combination with tillage. The high coefficients of variation of 137 Cs inventories for the 21 sampling rows, with a mean value of 44%, demonstrate the combined effects of variations in original microtopography, anthropogenic disturbance, the incohesive soils weathered from underlying granite, and the warm climate. Although earth-banked terraces can reduce soil erosion to some extent, the estimated erosion rates for the study area are still very high. - Highlights: • Earth-banked terraces are widely distributed in the Chinese Yimeng Mountains. • Spatial patterns of 137 Cs and erosion reflect terrace development processes. • Earth-banked terraces may limit soil erosion but rates

Environmental fate and behavior of persistent organic pollutants in Shergyla Mountain, southeast of the Tibetan Plateau of China

International Nuclear Information System (INIS)

Zhu, Nali; Schramm, Karl-Werner; Wang, Thanh; Henkelmann, Bernhard; Zheng, Xiaoyan; Fu, Jianjie; Gao, Yan

2014-01-01

Pristine mountains are ideal settings to study transport and behavior of persistent organic pollutants (POPs) along gradients of climate and land cover. The present work investigated the concentrations and patterns of 28 organochlorine pesticides (OCPs), 25 polychlorinated biphenyl (PCBs), 13 polybrominated diphenyl ethers (PBDEs), and 3 hexabromocyclododecane (HBCDs) isomers in the air of the Shergyla Mountain, southeastern Tibetan Plateau. Endosulfan I, hexachlorobenzene, pentachlorobenzene, hexachlorocyclohexanes and dichlorodibenzotrichloroethane and its degradation products (DDTs) were the predominant compounds while PBDEs and HBCDs showed the lowest background concentrations. Most of the target POPs had significantly higher concentrations in summer than those in winter. Increasing trends of the concentrations of DDTs and endosulfan were found with increasing altitude on the western slope in the Shergyla Mountain. Potential forest filter effect was observed based on the lower air concentrations of the target POPs in the forest than the ones out of the forest. - Highlights: • Concentrations of DDT and endosulfan increased with elevation in Shergyla Mountain. • Potential forest filter effect for some POPs was observed in summer in the Plateau. • Seasonal variations of POPs levels existed in atmosphere of the Plateau. • Different behavior of POPs was observed on the two slopes of the Shergyla Mountain. - Different behaviors of POPs were observed on the two slopes of the Shergyla Mountain, and potential forest filter effects for some POPs were observed in the summer

Giant Panda movement patterns in the Foping Nature Reserve, China

NARCIS (Netherlands)

Liu, X.; Skidmore, A.K.; Wang, T.; Yong, Y.; Prins, H.H.T.

2002-01-01

Observing the giant panda (Ailuropoda melanoleuca) in the remote mountains of Foping Nature Reserve (NR), China, is difficult due to the dense vegetation and steep terrain. Radiotracking is an effective way to study this animal and understand its behavior and habitat use. We used radiotracking data

Pacific Northwest Regional and Ecozone-scale Carbon Cycle Responses to 25 Years of Variation in Climate and Disturbance

Science.gov (United States)

Turner, D. P.; Ritts, W. D.; Kennedy, R. E.; Gray, A. N.; Yang, Z.

2015-12-01

Spatial variation in climate, soils, disturbance regime, and forest management - as well as temporal variation in weather - all influence terrestrial carbon sources and sinks. Spatially-distributed, process-based, carbon cycle simulation models provide a means to integrate information from these various influences to estimate carbon pools and flux over large domains. Here we apply the Biome-BGC model over the 4 state (OR, WA, ID, Western MT) Northwest U.S. region for the interval from 1986-2010. Landsat data was used to characterize disturbances and revealed that the overall disturbance rate on forest land across the region was 0.8 % yr-1, with 49 % as harvests, 28 % as fire, and 23 % as pest/pathogen. A large proportion of the harvested area was on private forestland (62 %) and a large proportion of total burned area was on public forestland (89 %). Net ecosystem production (NEP) for the 2006-2010 interval on forestland was predominantly positive (a carbon sink) throughout the region, with maximum values in the Coast Range, intermediate values in the Cascade Mountains, and relatively low values in the Inland Rocky Mountain ecoregions. Croplands throughout the region had consistently high NEP. Localized negative NEPs were mostly associated with recent disturbances. There was large interannual variation in regional NEP, with notably low values across the region in 2003. In all ecoregions there was a downward trend in NEP over the 25 year study period. The net ecosystem carbon balance was positive in OR, near neutral in ID and WA, and negative (a carbon source) MT. The Northwest region as a whole was a carbon sink in the 2006-2010 period.

An example postclosure risk assessment using the potential Yucca Mountain Site

International Nuclear Information System (INIS)

Doctor, P.G.; Eslinger, P.W.; Elwood, D.M.; Engel, D.W.; Freshley, M.D.; Liebetrau, A.M.; Reimus, P.W.; Strenge, D.L.; Tanner, J.E.; Van Luik, A.E.

1992-05-01

The risk analysis described in this document was performed for the US Department of Energy's (DOE) Office of Civilian Radioactive Waste Management (OCRWM) over a 2-year time period ending in June 1988. The objective of Pacific Northwest Laboratory's (PNL) task was to demonstrate an integrated, though preliminary, modeling approach for estimating the postclosure risk associated with a geologic repository for the disposal of high-level nuclear waste. The modeling study used published characterization data for the proposed candidate site at Yucca Mountain, Nevada, along with existing models and computer codes available at that time. Some of the site data and conceptual models reported in the Site Characterization Plan published in December 1988, however, were not yet available at the time that PNL conducted the modeling studies

The effect of conservation tillage on crop yield in China

Directory of Open Access Journals (Sweden)

Hongwen LI,Jin HE,Huanwen GAO,Ying CHEN,Zhiqiang ZHANG

2015-06-01

Full Text Available Traditional agricultural practices have resulted in decreased soil fertility, shortage of water resources and deterioration of agricultural ecological environment, which are seriously affecting grain production. Conservation tillage (CT research has been developed and applied in China since the 1960s and 1970s, and a series of development policies have been issued by the Chinese government. Recent research and application have shown that CT has positive effects on crop yields in China. According to the data from the Conservation Tillage Research Center (CTRC, Chinese Ministry of Agriculture (MOA, the mean crop yield increase can be at least 4% in double cropping systems in the North China Plain and 6% in single cropping systems in the dryland areas of North-east and North-west China. Crop yield increase was particularly significant in dryland areas and drought years. The mechanism for the yield increase in CT system can be attributed to enhanced soil water content and improved soil properties. Development strategies have been implemented to accelerate the adoption of CT in China.

Development of a geoscience database for preselecting China's high level radioactive waste disposal sites

International Nuclear Information System (INIS)

Li Jun; Fan Ai; Huang Shutao; Wang Ju

2004-01-01

Taking the development of a geoscience database for China's high level waste disposal sites: Yumen Town, Guansu province, northwest of China, as an example, this paper introduces in detail the application of Geographical Information System (GIS) to high level waste disposal and analyses its application prospect in other fields. The development of GIS provides brand-new thinking for administrators and technicians at all levels. At the same time, this paper also introduces the administration of maps and materials by using Geographical Information System. (author)

Effects of biochemical and physical processes on concentrations and size distributions of dimethylaminium and trimethylaminium in atmospheric particles from marginal seas of China to the northwest Pacific Ocean

Science.gov (United States)

Hu, Q.; Yao, X.; Qu, K.; Cui, Z.; Gao, H.; Xie, H.

2017-12-01

This study aim to assess the effects of concentrations and size distributions of aminium ions in atmospheric particles from offshore to open oceans. Size-segregated dimethylaminium (DMA+) and trimethylaminium (TMA+) in atmospheric particles were measured during March-May, 2014. One cruise was over marginal seas of China, in which the concentrations of DMA+ and TMA+ in PM0.056-10 varied from 0.08 nmol m-3 to 0.43 nmol m-3 and from 0.10 to 0.27 nmol m-3, respectively. The two ions both had good positive correlations with subsurface chlorophyll-a maximum and salinity, respectively. The highest concentrations of (DMA+ + TMA+) were observed during cyanobacteria bloom period which happened in subsurface water. The results implied that the concentrations of DMA+ (TMA+) in marine atmospheric particles might be influenced by phytoplankton quantities and species in subsurface seawater. Another cruise was carried out from marginal seas of China to the northwest Pacific Ocean (NWPO). The concentrations of DMA+ and TMA+ in PM0.056-1.8 varied from 0.19 nmol m-3 to 1.53 nmol m-3 and from 0.57 to 3.85 nmol m-3, respectively. The highest (lowest) concentrations of (DMA+ + TMA+) were observed near the cyclonic (anticyclonic) eddy, indicating that the cyclonic (anticyclonic) eddy with high (low) chlorophyll-a enhanced (suppressed) DMA+ (TMA+) production in atmospheric particles. In addition, the dominant particle modes less than 0.2 μm for DMA+ (TMA+) were observed, ie., 0.13±0.02 μm for DMA+ over marginal seas of China, and 0.08±0.00 μm for TMA+ in NWPO, but if they were emitted via bubble bursting needed to be further researched.

Uplifting model of the Longmenshan mountain in the eastern margin of Tibetan plateau

Science.gov (United States)

Zhang, S.; Ding, R.; Mao, C.

2010-12-01

Longmenshan mountain is a vivid manifestation of the Cenozoic orogenesis in the eastern margin of the Tibetan plateau, and a key to understand the geodynamics of eastward extending of the plateau. Thus the uplift mechanism of Longmenshan mountain became a hot spot issue of geosciences about the Tibetan plateau. Two entirely different hypotheses, i.e., crustal shortening and lower crustal channel flow, were put forward, but the solution is open. Further discussion need our deeper understanding about the uplifting features of the Longmenshan mountain. Fortunately, the uplifting processes were recorded objectively by peneplains and river landforms. We first analysed the peneplains and pediplanes of Longmenshan mountain and its surrounding areas, and surveyed the terraces of Dadu river running across the mountain. Then we studied the uplifting features of the study areas in late Cenozoic time on the basis of landform geometries. Finaly we discussed the possible mechanisms for the uplifting. There are two levels of peneplains whose peneplanations may begin in early Cenozoic time and end at late Miocene when the final fluctuations of elevations were possibly less than one kilometers. The valley of Dadu river is incised into the peneplains and has a staircase of no less than ten levels of terraces. The highest terrace is a strath which was contemporary with the pediplane in the piedmont formed in late Pliocene or in early Pleistocene. Due to their originally flat features, the peneplains and the strath terraces were used as datum planes for judging neotectonic deformations. Since late Miocene, the southeastern side of Longmenshan mountain has been dominated by thrust-faulting with a total vertical displacement of about 4500 m against the Sichuan basin, meantime the northwest side has been maintained flexural uplift with syncline hinge approximately following the Longriba fault. As a landform barrier between Tibetan plateau and Sichuan basin, the crest lines of the

Hydroclimate of the Spring Mountains and Sheep Range, Clark County, Nevada

Science.gov (United States)

Moreo, Michael T.; Senay, Gabriel B.; Flint, Alan L.; Damar, Nancy A.; Laczniak, Randell J.; Hurja, James

2014-01-01

Precipitation, potential evapotranspiration, and actual evapotranspiration often are used to characterize the hydroclimate of a region. Quantification of these parameters in mountainous terrains is difficult because limited access often hampers the collection of representative ground data. To fulfill a need to characterize ecological zones in the Spring Mountains and Sheep Range of southern Nevada, spatially and temporally explicit estimates of these hydroclimatic parameters are determined from remote-sensing and model-based methodologies. Parameter-elevation Regressions on Independent Slopes Model (PRISM) precipitation estimates for this area ranges from about 100 millimeters (mm) in the low elevations of the study area (700 meters [m]) to more than 700 mm in the high elevations of the Spring Mountains (> 2,800 m). The PRISM model underestimates precipitation by 7–15 percent based on a comparison with four high‑elevation precipitation gages having more than 20 years of record. Precipitation at 3,000-m elevation is 50 percent greater in the Spring Mountains than in the Sheep Range. The lesser amount of precipitation in the Sheep Range is attributed to partial moisture depletion by the Spring Mountains of eastward-moving, cool-season (October–April) storms. Cool-season storms account for 66–76 percent of annual precipitation. Potential evapotranspiration estimates by the Basin Characterization Model range from about 700 mm in the high elevations of the Spring Mountains to 1,600 mm in the low elevations of the study area. The model realistically simulates lower potential evapotranspiration on northeast-to-northwest facing slopes compared to adjacent southeast-to-southwest facing slopes. Actual evapotranspiration, estimated using a Moderate Resolution Imaging Spectroradiometer based water-balance model, ranges from about 100 to 600 mm. The magnitude and spatial variation of simulated, actual evapotranspiration was validated by comparison to PRISM precipitation

Mountain home known geothermal resource area: an environmental analysis

Energy Technology Data Exchange (ETDEWEB)

Spencer, S.G.; Russell, B.F. (eds.)

1979-09-01

The Mountain Home KGRA encompasses an area of 3853 hectares (ha) at the foot of the Mount Bennett Hills in Elmore County, Idaho. The site is associated with an arid climate and high winds that generate an acute dust problem. The KGRA lies adjacent to the northwest-southeast trending fault zone that reflects the northern boundary of the western Snake River Plain graben. Data indicate that a careful analysis of the subsidence potential is needed prior to extensive geothermal development. Surface water resources are confined to several small creeks. Lands are utilized for irrigated farmlands and rangeland for livestock. There are no apparent soil limitations to geothermal development. Sage grouse and mule deer are the major species of concern. The potential of locating significant heritage resources other than the Oregon Trail or the bathhouse debris appears to be relatively slight.

Scenario-Based Impact Assessment of Land Use/Cover and Climate Changes on Watershed Hydrology in Heihe River Basin of Northwest China

Directory of Open Access Journals (Sweden)

Feng Wu

2015-01-01

Full Text Available This study evaluated hydrological impacts of potential climate and land use changes in Heihe River Basin of Northwest China. The future climate data for the simulation with Soil and Water Assessment Tool (SWAT were prepared using a dynamical downscaling method. The future land uses were simulated with the Dynamic Land Use System (DLS model by establishing Multinomial Logistic Regression (MNL model for six land use types. In 2006–2030, land uses in the basin will experience a significant change with a prominent increase in urban areas, a moderate increase in grassland, and a great decrease in unused land. Besides, the simulation results showed that in comparison to those during 1981–2005 the temperature and precipitation during 2006–2030 will change by +0.8°C and +10.8%, respectively. The land use change and climate change will jointly make the water yield change by +8.5%, while they will separately make the water yield change by −1.8% and +9.8%, respectively. The predicted large increase in future precipitation and the corresponding decrease in unused land will have substantial impacts on the watershed hydrology, especially on the surface runoff and streamflow. Therefore, to mitigate negative hydrological impacts and utilize positive impacts, both land use and climate changes should be considered in water resource planning for the Heihe River Basin.

1993 Pacific Northwest Loads and Resources Study.

Energy Technology Data Exchange (ETDEWEB)

United States. Bonneville Power Administration.

1993-12-01

The Loads and Resources Study is presented in three documents: (1) this summary of Federal system and Pacific Northwest region loads and resources; (2) a technical appendix detailing forecasted Pacific Northwest economic trends and loads, and (3) a technical appendix detailing the loads and resources for each major Pacific Northwest generating utility. In this loads and resources study, resource availability is compared with a range of forecasted electricity consumption. The forecasted future electricity demands -- firm loads -- are subtracted from the projected capability of existing and {open_quotes}contracted for{close_quotes} resources to determine whether Bonneville Power Administration (BPA) and the region will be surplus or deficit. If resources are greater than loads in any particular year or month, there is a surplus of energy and/or capacity, which BPA can sell to increase revenues. Conversely, if firm loads exceed available resources, there is a deficit of energy and/or capacity, and additional conservation, contract purchases, or generating resources will be needed to meet load growth. The Pacific Northwest Loads and Resources Study analyzes the Pacific Northwest`s projected loads and available generating resources in two parts: (1) the loads and resources of the Federal system, for which BPA is the marketing agency; and (2) the larger Pacific Northwest regional power system, which includes loads and resource in addition to the Federal system. The loads and resources analysis in this study simulates the operation of the power system under the Pacific Northwest Coordination Agreement (PNCA) produced by the Pacific Northwest Coordinating Group. This study presents the Federal system and regional analyses for five load forecasts: high, medium-high, medium, medium-low, and low. This analysis projects the yearly average energy consumption and resource availability for Operating Years (OY) 1994--95 through 2003--04.

Exploring Northwest China's agricultural water-saving strategy: analysis of water use efficiency based on an SE-DEA model conducted in Xi'an, Shaanxi Province.

Science.gov (United States)

Mu, L; Fang, L; Wang, H; Chen, L; Yang, Y; Qu, X J; Wang, C Y; Yuan, Y; Wang, S B; Wang, Y N

Worldwide, water scarcity threatens delivery of water to urban centers. Increasing water use efficiency (WUE) is often recommended to reduce water demand, especially in water-scarce areas. In this paper, agricultural water use efficiency (AWUE) is examined using the super-efficient data envelopment analysis (DEA) approach in Xi'an in Northwest China at a temporal and spatial level. The grey systems analysis technique was then adopted to identify the factors that influenced the efficiency differentials under the shortage of water resources. From the perspective of temporal scales, the AWUE increased year by year during 2004-2012, and the highest (2.05) was obtained in 2009. Additionally, the AWUE was the best in the urban area at the spatial scale. Moreover, the key influencing factors of the AWUE are the financial situations and agricultural water-saving technology. Finally, we identified several knowledge gaps and proposed water-saving strategies for increasing AWUE and reducing its water demand by: (1) improving irrigation practices (timing and amounts) based on compatible water-saving techniques; (2) maximizing regional WUE by managing water resources and allocation at regional scales as well as enhancing coordination among Chinese water governance institutes.

Effects of Long-Term Dust Exposure on Human Respiratory System Health in Minqin County, China.

Science.gov (United States)

Wang, Jinyu; Li, Sheng; Wang, Shigong; Shang, Kezheng

2015-01-01

The aim of this study was to assess the effects of long-term sand dust exposure on human respiratory health. Dust events break out frequently in Minqin County, northwest China, whereas Pingliang City, northwest China, is rarely influenced by dust events. Therefore, Minqin and Pingliang were selected as sand dust exposure region and control area, respectively. The incidence of respiratory system diseases and symptoms was determined through a structured respiratory health questionnaire (ATS-DLD-78-A) and personal interviews. The subjects comprised 728 farmers (Minqin, 424; Pingliang, 304) aged 40 years or older, who had nondocumented occupational history to industrial dust exposure. Prevalences (odds ratio [OR], 95% confidence interval [CI]) of chronic rhinitis, chronic bronchitis, and chronic cough increased 9.6% (3.141, 1.776-5.555), 7.5% (2.468, 1.421-4.286), and 10.2% (1.787, 1.246-2.563) in Minqin comparison with Pingliang, respectively, and the differences were significant (p <.01).

Responses of Vegetation Growth to Climatic Factors in Shule River Basin in Northwest China: A Panel Analysis

Directory of Open Access Journals (Sweden)

Jinghui Qi

2017-03-01

Full Text Available The vegetation response to climatic factors is a hot topic in global change research. However, research on vegetation in Shule River Basin, which is a typical arid region in northwest China, is still limited, especially at micro scale. On the basis of Moderate-resolution Imaging Spectroradiometer (MODIS Normalized Difference Vegetation Index (NDVI data and daily meteorological data, employing panel data models and other mathematical models, the aim of this paper is to reveal the interactive relationship between vegetation variation and climatic factors in Shule River Basin. Results show that there is a widespread greening trend in the whole basin during 2000–2015, and 80.28% of greening areas (areas with vegetation improvement are distributed over upstream region, but the maximum vegetation variation appears in downstream area. The effects of climate change on NDVI lag about half to one month. The parameters estimated using panel data models indicate that precipitation and accumulated temperature have positive contribution to NDVI. With every 1-mm increase in rainfall, NDVI increases by around 0.223‰ in upstream area and 0.6‰ in downstream area. With every 1-°C increase in accumulated temperature, NDVI increases by around 0.241‰ in upstream area and 0.174‰ in downstream area. Responses of NDVI to climatic factors are more sensitive when these factors are limiting than when they are not limiting. NDVI variation has performance in two seasonal and inter-annual directions, and the range of seasonal change is far more than that of inter-annual change. The inverted U-shaped curve of the variable intercepts reflects the seasonal change. Our results might provide some scientific basis for the comprehensive basin management.

Two new species of Indonemoura (Plecoptera: Nemouridae) from Yunnan Province of southwestern China.

Science.gov (United States)

Li, Weihai; Wu, Limin; Yang, Ding

2017-02-09

Two new species of the nemourid genus Indonemoura are described, Indonemoura curvispina sp. nov. and I. spirocornua sp. nov., from the Gaoligong Mountains of Yunnan Province of southwestern China. The taxonomic relationships with related species are discussed.

Individual particle analysis of aerosols collected under haze and non-haze conditions at a high-elevation mountain site in the North China plain

Directory of Open Access Journals (Sweden)

W. J. Li

2011-11-01

Full Text Available The North China plain is a region with megacities and huge populations. Aerosols over the highly polluted area have a significant impact on the regional and global climate. In order to investigate the physical and chemical characteristics of aerosol particles in elevated layers there, observations were carried out at the summit of Mt. Tai (1534 m a.s.l. from 19 to 28 April, 2010, when the air masses were advected from the east (phase-I: 19–21 April, from the south (phase-II: 22–25 April, and from the northwest (phase-III: 26–28 April. Individual aerosol particles were identified with transmission electron microscopy (TEM, new particle formation (NPF and growth events were monitored by a wide-range particle spectrometer, and ion concentrations in PM_2.5 were analyzed. During phase-I and phase-II, haze layers caused by anthropogenic pollution were observed, and a high percentage of particles were sulfur-rich (47–49%. In phase-III, the haze disappeared due to the intrusion of cold air from the northwest, and mineral dust particles from deserts were dominant (43%. NPF followed by particle growth during daytime was more pronounced on hazy than on clear days. Particle growth during daytime resulted in an increase of particle geometric mean diameter from 10–22 nm in the morning to 56–96 nm in the evening. TEM analysis suggests that sulfuric acid and secondary organic compounds should be important factors for particle nucleation and growth. However, the presence of fine anthropogenic particles (e.g., soot, metal, and fly ash embedded within S-rich particles indicates that they could weaken NPF and enhance particle growth through condensation and coagulation. Abundant mineral particles in phase-III likely suppressed the NPF processes because they supplied sufficient area on which acidic gases or acids condensed.

Pacific Northwest Salmon Habitat Project Database

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — In the Pacific Northwest Salmon Habitat Project Database Across the Pacific Northwest, both public and private agents are working to improve riverine habitat for a...

Speciation, sources, and risk assessment of heavy metals in suburban vegetable garden soil in Xianyang City, Northwest China

Science.gov (United States)

Wang, Lijun; Tao, Wendong; Smardon, Richard C.; Xu, Xue; Lu, Xinwei

2018-06-01

Intensive anthropogenic activities can lead to soil heavy metal contamination resulting in potential risks to the environment and to human health. To reveal the concentrations, speciation, sources, pollution level, and ecological risk of heavy metals in vegetable garden soil, a total of 136 soil samples were collected from three vegetable production fields in the suburbs of Xianyang City, Northwest China. These samples were analyzed by inductively coupled plasma- atomic emission spectrometry and atomic fluorescence spectrometry. The results showed that the mean concentrations of Cd, Co, Cu, Mn, Pb, Zn, and Hg in vegetable garden soil were higher than the corresponding soil element background values of Shaanxi Province. The heavy metals studied in vegetable garden soil were primarily found in the residual fraction, averaging from 31.26% (Pb) to 90.23% (Cr). Considering the non-residual fractions, the mobility or potential risk was in the order of Pb (68.74%)>Co (60.54%)>Mn (59.28%) >Cd (53.54%) ≫Ni (23.36%) >Zn (22.73%)>Cu (14.93%)>V (11.81%)>Cr (9.78%). Cr, Mn, Ni, V, and As in the studied soil were related to soilforming parent materials, while Cu, Hg, Zn, Cd, Co, and Pb were associated with the application of plastic films, fertilizers, and pesticides, as well as traffic emissions and industrial fumes. Cr, Ni, V, and As presented low contamination levels, whereas Co, Cu, Mn, Pb, and Zn levels were moderate, and Cd and Hg were high. Ecological risk was low for Co, Cr, Cu, Mn, Pb, Zn, and As, with high risk observed for Cd and Hg. The overall pollution level and ecological risk of these heavy metals were high.

Speciation, sources, and risk assessment of heavy metals in suburban vegetable garden soil in Xianyang City, Northwest China

Science.gov (United States)

Wang, Lijun; Tao, Wendong; Smardon, Richard C.; Xu, Xue; Lu, Xinwei

2017-07-01

Intensive anthropogenic activities can lead to soil heavy metal contamination resulting in potential risks to the environment and to human health. To reveal the concentrations, speciation, sources, pollution level, and ecological risk of heavy metals in vegetable garden soil, a total of 136 soil samples were collected from three vegetable production fields in the suburbs of Xianyang City, Northwest China. These samples were analyzed by inductively coupled plasma- atomic emission spectrometry and atomic fluorescence spectrometry. The results showed that the mean concentrations of Cd, Co, Cu, Mn, Pb, Zn, and Hg in vegetable garden soil were higher than the corresponding soil element background values of Shaanxi Province. The heavy metals studied in vegetable garden soil were primarily found in the residual fraction, averaging from 31.26% (Pb) to 90.23% (Cr). Considering the non-residual fractions, the mobility or potential risk was in the order of Pb (68.74%)>Co (60.54%)>Mn (59.28%) >Cd (53.54%) ≫Ni (23.36%) >Zn (22.73%)>Cu (14.93%)>V (11.81%)>Cr (9.78%). Cr, Mn, Ni, V, and As in the studied soil were related to soilforming parent materials, while Cu, Hg, Zn, Cd, Co, and Pb were associated with the application of plastic films, fertilizers, and pesticides, as well as traffic emissions and industrial fumes. Cr, Ni, V, and As presented low contamination levels, whereas Co, Cu, Mn, Pb, and Zn levels were moderate, and Cd and Hg were high. Ecological risk was low for Co, Cr, Cu, Mn, Pb, Zn, and As, with high risk observed for Cd and Hg. The overall pollution level and ecological risk of these heavy metals were high.

Discrete wavelet transform-based investigation into the variability of standardized precipitation index in Northwest China during 1960-2014

Science.gov (United States)

Yang, Peng; Xia, Jun; Zhan, Chesheng; Zhang, Yongyong; Hu, Sheng

2018-04-01

In this study, the temporal variations of the standard precipitation index (SPI) were analyzed at different scales in Northwest China (NWC). Discrete wavelet transform (DWT) was used in conjunction with the Mann-Kendall (MK) test in this study. This study also investigated the relationships between original precipitation and different periodic components of SPI series with datasets spanning 55 years (1960-2014). The results showed that with the exception of the annual and summer SPI in the Inner Mongolia Inland Rivers Basin (IMIRB), spring SPI in the Qinghai Lake Rivers Basin (QLRB), and spring SPI in the Central Asia Rivers Basin (CARB), it had an increasing trend in other regions for other time series. In the spring, summer, and autumn series, though the MK trends test in most areas was at the insignificant level, they showed an increasing trend in precipitation. Meanwhile, the SPI series in most subbasins of NWC displayed a turning point in 1980-1990, with the significant increasing levels after 2000. Additionally, there was a significant difference between the trend of the original SPI series and the largest approximations. The annual and seasonal SPI series were composed of the short periodicities, which were less than a decade. The MK value would increase by adding the multiple D components (and approximations), and the MK value of the combined series was in harmony with that of the original series. Additionally, the major trend of the annual SPI in NWC was based on the four kinds of climate indices (e.g., Atlantic Oscillation [AO], North Atlantic Oscillation [NAO], Pacific Decadal Oscillation [PDO], and El Nino-Southern Oscillation index [ENSO/NINO]), especially the ENSO.

Management of radioactive wastes in China

International Nuclear Information System (INIS)

Pan Ziqiang

1994-01-01

The policy and principles on management of radioactive wastes are stipulated. Cement solidification and bituminization unit has come into trial run. Solid radioactive waste is stored in tentative storage vault built in each of nuclear facilities. Seventeen storages associated with applications of nuclear technology and radioisotopes have been built for provinces. Disposal of low and intermediate level radioactive wastes pursues the policy of 'regional disposal'. Four repositories have been planned to be built in northwest, southwest, south and east China respectively. A program for treatment and disposal of high level radioactive waste has been made

Irradiation of Northwest agricultural products

International Nuclear Information System (INIS)

Eakin, D.E.; Tingey, G.L.; Anderson, D.B.; Hungate, F.P.

1985-01-01

Irradiation of food for disinfestation and preservation is increasing in importance because of increasing resrictions on various chemical treatments. Irradiation treatment is of particular interest in the Northwest because of a growing supply of agricultural products and the need to develop new export markets. Several products have, or could potentially have, significant export markets if stringent insect control procedures are developed and followed. Due to the recognized potential benefits of irradiation, Pacific Northwest Laboratory (PNL) is conducting this program to evaluate the benefits of using irradiation on Northwest agricultural products under the US Department of Energy (DOE) Defense Byproducts Production and Utilization Program. Commodities currently included in the program are cherries, apples, asparagus, spices, hay, and hides

Irradiation of Northwest agricultural products

International Nuclear Information System (INIS)

Eakin, D.E.; Tingey, G.L.

1985-02-01

Irradiation of food for disinfestation and preservation is increasing in importance because of increasing restrictions on various chemical treatments. Irradiation treatment is of particular interest in the Northwest because of a growing supply of agricultural products and the need to develop new export markets. Several products have, or could potentially have, significant export markets if stringent insect control procedures are developed and followed. Due to the recognized potential benefits of irradiation, Pacific Northwest Laboratory (PNL) is conducting this program to evaluate the benefits of using irradiation on Northwest agricultural products under the US Department of Energy (DOE) Defense Byproducts Production and Utilization Program. Commodities currently included in the program are cherries, apples, asparagus, spices, hay, and hides

Abundance, distribution and conservation status of Siberian ibex, Marco Polo and Blue sheep in Karakoram-Pamir mountain area

Directory of Open Access Journals (Sweden)

Babar Khan

2016-07-01

Full Text Available This study was carried out to investigate abundance, distribution, structure and conservation status of three major ungulate species viz., Capra sibirica, Pseudois nayaur and Ovis ammon polii, in the Karakoram-Pamir mountain area between China and Pakistan. Results showed that the entire study area had a scattered but worthwhile population of Siberian ibex, Blue sheep and Marco Polo sheep, except Khunjerab Pass, Koksil-Pateshek and Barkhun areas of Khunjerab National Park (KNP. Large groups of Blue sheep were sighted in Shimshal and Barkhun valleys (KNP but it did not show up in the Muztagh part of Taxkorgan Nature Reserve (TNR in China. Despite scarcity of natural vegetation and extreme climate, estimated abundance of ibex and Marco Polo sheep was not different from that in Protected Areas of Nepal, China, and India, except for Blue sheep. Marco Polo sheep, Blue sheep and Snow leopard roam across international borders among China, Pakistan and other adjacent countries. Illegal hunting and poaching, removal of natural vegetation for fodder and firewood, and over grazing of pastures by livestock were main habitat issues whereas, border fencing for security reasons, has been a major impediment restricting free movement of the wildlife across international borders. A science based conservation and development strategy is proposed to restore viable wildlife populations and maintain ecological flows of Karakoram Pamir Mountains to benefit both the wild species and the local human communities.

A new species of Nemacerota Hampson, [1893] (Lepidoptera, Thyatiridae) from Tibet, China.

Science.gov (United States)

Pan, Zhao-Hui; Ronkay, Gábor; Ronkay, László; Han, Hui-Lin

2014-01-13

The genus Nemacerota Hampson, [1893] includes 14 species worldwide, which are mainly distributed from Pakistan along the main Himalayan chain, the eastern frontier of the Tibetan plateau and the Central Chinese mountains to the northern Pacific regions. Ten species have been recorded from China. Among them, only N. tancrei (Graeser, 1888) occurs in NE China, whereas all other taxa inhabit mountainous areas in Central China, the eastern frontier of the Tibetan plateau or Tibet. N. igorkostjuki Laszlo, Ronkay, Ronkay & Witt, 2007 is found only in the southern edge of Tibet (Nyalam = Nielamu); N. mandibulata Laszlo, Ronkay, Ronkay & Witt, 2007, N. taurina Laszlo, Ronkay, Ronkay & Witt, 2007, N. stueningi Laszlo, Ronkay, Ronkay & Witt, 2007, N. pectinata (Houlbert, 1921), N. inouei Laszlo, Ronkay, Ronkay & Witt, 2007 and N. owadai Laszlo, Ronkay, Ronkay & Witt, 2007 are known from Mt. Taibaishan, Shaanxi Province; N. griseobasalis (Sick, 1941), N. decorata (Sick, 1941) and N. pectinata (Houlbert, 1921) occur in the northwestern parts of Yunnan Province (and, possibly, also in southern Sichuan).        Here we describe a new species from the Linzhi area, Autonomous Region Xizang (Tibet), China. Specimens were dissected and examined using standard methods; adult photographs were photographed with a Nikon D700; genitalic slides were photographed using the Qcapture pro system, and processed in Adobe Photoshop CS5 software.

The Variations of Land Surface Phenology in Northeast China and Its Responses to Climate Change from 1982 to 2013

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Jianjun Zhao

2016-05-01

Full Text Available Northeast China is located at high northern latitudes and is a typical region of relatively high sensitivity to global climate change. Studies of the land surface phenology in Northeast China and its response to climate change are important for understanding global climate change. In this study, the land surface phenology parameters were calculated using the third generation dataset from the Global Inventory Modeling and Mapping Studies (GIMMS 3g that was collected from 1982 to 2013 were estimated to analyze the variations of the land surface phenology in Northeast China at different scales and to discuss the internal relationships between phenology and climate change. We examined the phonological changes of all ecoregions. The average start of the growing season (SOS did not exhibit a significant trend throughout the study area; however, the end of the growing season (EOS was significantly delayed by 4.1 days or 0.13 days/year (p < 0.05 over the past 32 years. The SOS for the Hulunbuir Plain, Greater Khingan Mountains and Lesser Khingan Mountains was earlier, and the SOS for the Sanjing, Songnen and Liaohe Plains was later. In addition, the EOS of the Greater Khingan Mountains, Lesser Khingan Mountains and Changbai Mountains was later than the EOS of the Liaohe Plain. The spring temperature had the greatest impact on the SOS. Precipitation had an insignificant impact on forest SOS and a relatively large impact on grassland SOS. The EOS was affected by both temperature and precipitation. Furthermore, although temperature had a lag effect on the EOS, no significant lag effect was observed for the SOS.

Current and Potential Tree Locations in Tree Line Ecotone of Changbai Mountains, Northeast China: The Controlling Effects of Topography

OpenAIRE

Zong, Shengwei; Wu, Zhengfang; Xu, Jiawei; Li, Ming; Gao, Xiaofeng; He, Hongshi; Du, Haibo; Wang, Lei

2014-01-01

Tree line ecotone in the Changbai Mountains has undergone large changes in the past decades. Tree locations show variations on the four sides of the mountains, especially on the northern and western sides, which has not been fully explained. Previous studies attributed such variations to the variations in temperature. However, in this study, we hypothesized that topographic controls were responsible for causing the variations in the tree locations in tree line ecotone of the Changbai Mountain...

Using the nonlinear aquifer storage–discharge relationship to simulate the base flow of glacier- and snowmelt-dominated basins in northwest China

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R. Gan

2013-09-01

Full Text Available Base flow is an important component in hydrological modeling. This process is usually modeled by using the linear aquifer storage–discharge relation approach, although the outflow from groundwater aquifers is nonlinear. To identify the accuracy of base flow estimates in rivers dominated by snowmelt and/or glacier melt in arid and cold northwestern China, a nonlinear storage–discharge relationship for use in SWAT (Soil Water Assessment Tool modeling was developed and applied to the Manas River basin in the Tian Shan Mountains. Linear reservoir models and a digital filter program were used for comparisons. Meanwhile, numerical analysis of recession curves from 78 river gauge stations revealed variation in the parameters of the nonlinear relationship. It was found that the nonlinear reservoir model can improve the streamflow simulation, especially for low-flow period. The higher Nash–Sutcliffe efficiency, logarithmic efficiency, and volumetric efficiency, and lower percent bias were obtained when compared to the one-linear reservoir approach. The parameter b of the aquifer storage–discharge function varied mostly between 0.0 and 0.1, which is much smaller than the suggested value of 0.5. The coefficient a of the function is related to catchment properties, primarily the basin and glacier areas.

Using the nonlinear aquifer storage-discharge relationship to simulate the base flow of glacier- and snowmelt-dominated basins in northwest China

Science.gov (United States)

Gan, R.; Luo, Y.

2013-09-01

Base flow is an important component in hydrological modeling. This process is usually modeled by using the linear aquifer storage-discharge relation approach, although the outflow from groundwater aquifers is nonlinear. To identify the accuracy of base flow estimates in rivers dominated by snowmelt and/or glacier melt in arid and cold northwestern China, a nonlinear storage-discharge relationship for use in SWAT (Soil Water Assessment Tool) modeling was developed and applied to the Manas River basin in the Tian Shan Mountains. Linear reservoir models and a digital filter program were used for comparisons. Meanwhile, numerical analysis of recession curves from 78 river gauge stations revealed variation in the parameters of the nonlinear relationship. It was found that the nonlinear reservoir model can improve the streamflow simulation, especially for low-flow period. The higher Nash-Sutcliffe efficiency, logarithmic efficiency, and volumetric efficiency, and lower percent bias were obtained when compared to the one-linear reservoir approach. The parameter b of the aquifer storage-discharge function varied mostly between 0.0 and 0.1, which is much smaller than the suggested value of 0.5. The coefficient a of the function is related to catchment properties, primarily the basin and glacier areas.

Precipitation alters plastic film mulching impacts on soil respiration in an arid area of northwest China

Science.gov (United States)

Ming, Guanghui; Hu, Hongchang; Tian, Fuqiang; Peng, Zhenyang; Yang, Pengju; Luo, Yiqi

2018-05-01

Plastic film mulching (PFM) has widely been used around the world to save water and improve crop yield. However, the effect of PFM on soil respiration (Rs) remains unclear and could be further confounded by irrigation and precipitation. To address these topics, controlled experiments were conducted in mulched and non-mulched fields under drip irrigation from 2014 to 2016 in an arid area of the Xinjiang Uygur Autonomous Region, northwest China. The spatio-temporal pattern of soil surface CO2 flux as an index of soil respiration under drip irrigation with PFM was investigated, and the confounded effects of PFM and irrigation/precipitation on soil respiration were explored. The main findings were as follows. (1) Furrows, planting holes, and plastic mulch are three important pathways of soil CO2 emissions in mulched fields, of which the planting hole efflux outweighs that from the furrow, with the largest values of 8.0 and 6.6 µmol m-2 s-1, respectively, and the plastic mulch itself can emit up to 3.6 µmol m-2 s-1 of CO2. (2) The frequent application of water (i.e. through irrigation and precipitation) elevates soil moisture and soil respiration and enhances their variation. The resultant higher variation of soil moisture further alleviates the sensitivity of soil respiration to soil temperature, leading to a weak correlation and lower Q10 values. (3) Soil CO2 effluxes from furrows and ridges in mulched fields outweigh the corresponding values in non-mulched fields in arid areas. However, this outweighing relation attenuates with increasing precipitation. Furthermore, by combining our results with those from the literature, we show that the difference in soil CO2 effluxes between non-mulched and mulched fields presents a linear relation with the amount of precipitation, which results in negative values in arid areas and positive values in humid areas. Therefore, whether PFM increases soil respiration or not depends on the amount of precipitation during the crop

Research on the spatial structure of crude oil flow and the characteristics of its flow field in China

International Nuclear Information System (INIS)

Zhao, Yuan; Hao, Li-Sha; Wan, Lu

2007-01-01

Crude oil flow is a sort of oil spatial movement, and in China, it is large scale and covers wide area with extensive social-economic effects. This paper analyses the spatial structure of crude oil flow in China, the characters of its flow field and the layout of its flow track. The results show that oil flow in China has a spatial characteristic of centralized output and decentralized input; its spatial structure is composed of Source System in the shape of right-angled triangle, Confluence System in the shape of right-angled trapezium and Multiplex System in the shape of obtuse-angled triangle, which are mutually nested, and on a whole, the presence of Multiplex System balances and optimizes the flow layout; oil flow field in China can be divided into four parts, i.e. the North, North-west, East and South Field, two or three of which overlap with each other, extending the oil flow and making the flow more flexible and maneuverable; oil flow track is a multi-objective decision-making route and in the decision-making process oil transportation cost is one of the essential factors, in China, oil flow track falls into the Northeast, North, East, Northwest and South five cluster regions, which connect with each other, and series-parallel connection between various kinds of transportation channels is widely seen in them, reinforcing the supply security of crude oil

Trend of extreme precipitation events over China in last 40 years

International Nuclear Information System (INIS)

Zhang Daquan; Hu Jingguo; Feng Guolin

2008-01-01

Using the daily precipitation data of 740 stations in China from 1960 to 2000, the analysis on the variations and distributions of the frequency and the percentage of extreme precipitation to the annual rainfall have been performed in this paper. Results indicate that the percentage of heavy rains (above 25mm/day) in the annual rainfall has increased, while on average the day number of heavy rains has slightly reduced during the past 40 years. In the end of 1970s and the beginning of 1980s, both the number of days with extreme precipitation and the percentage of extreme precipitation abruptly changed over China, especially in the northern China. By moving t test, the abrupt change year of extreme precipitation for each station and its spatial distribution over the whole country are also obtained. The abrupt change years concentrated in 1978–1982 for most regions of northern China while occurred at various stations in southern China in greatly different/diverse years. Besides the abrupt change years of extreme precipitation at part stations of Northwest China happened about 5 years later in comparison with that of the country's average

Genetic Structure and Eco-Geographical Differentiation of Wild Sheep Fescue (Festuca ovina L. in Xinjiang, Northwest China

Directory of Open Access Journals (Sweden)

Chenglin Zhang

2017-08-01

Full Text Available Glaciation and mountain orogeny have generated new ecologic opportunities for plants, favoring an increase in the speciation rate. Moreover, they also act as corridors or barriers for plant lineages and populations. High genetic diversity ensures that species are able to survive and adapt. Gene flow is one of the most important determinants of the genetic diversity and structure of out-crossed species, and it is easily affected by biotic and abiotic factors. The aim of this study was to characterize the genetic diversity and structure of an alpine species, Festuca ovina L., in Xinjiang, China. A total of 100 individuals from 10 populations were analyzed using six amplified fragment length polymorphism (AFLP primer pairs. A total of 583 clear bands were generated, of which 392 were polymorphic; thus, the percentage of polymorphic bands (PPB was 67.24%. The total and average genetic diversities were 0.2722 and 0.2006 (0.1686–0.2225, respectively. The unweighted group method with arithmetic mean (UPGMA tree, principal coordinates analysis (PCoA and Structure analyses revealed that these populations or individuals could be clustered into two groups. The analysis of molecular variance analysis (AMOVA suggested that most of the genetic variance existed within a population, and the genetic differentiation (Fst among populations was 20.71%. The Shannon differentiation coefficient (G’st among populations was 0.2350. Limited gene flow (Nm = 0.9571 was detected across all sampling sites. The Fst and Nm presented at different levels under the genetic barriers due to fragmentation. The population genetic diversity was significant relative to environmental factors such as temperature, altitude and precipitation.

Mountains

Science.gov (United States)

Regina M. Rochefort; Laurie L. Kurth; Tara W. Carolin; Robert R. Mierendorf; Kimberly Frappier; David L. Steenson

2006-01-01

This chapter concentrates on subalpine parklands and alpine meadows of southern British Columbia, Washington, Oregon, and western Montana. These areas lie on the flanks of several mountain ranges including the Olympics, the Cascades of Oregon and Washington, and the Coast Mountains in British Columbia.

Geological factors of disposal site selection for low-and intermediate-level solid radwastes in China

International Nuclear Information System (INIS)

Chen Zhangru

1993-01-01

For disposal of low- and intermediate-level solid radioactive wastes, shallow-ground disposal can provide adequate isolation of waste from human for a fairly long period of time. The objective of disposal site selection is to ensure that the natural properties of the site together with the engineered barrier site shall provide adequate isolation of radionuclides from the human beings and environment, so the whole disposal system can keep the radiological impact within an acceptable level. Since the early 1980's, complying with the national standards and the expert's conception as well as the related IAEA Criteria, geological selection of disposal sites for low-and intermediate-level solid radwastes has been carried out in East China, South China, Northwest China and Southwest China separately. Finally, 5 candidate sites were recommended to the CNNC

Quantitative analysis of agricultural land use change in China

Science.gov (United States)

Chou, Jieming; Dong, Wenjie; Wang, Shuyu; Fu, Yuqing

This article reviews the potential impacts of climate change on land use change in China. Crop sown area is used as index to quantitatively analyze the temporal-spatial changes and the utilization of the agricultural land. A new concept is defined as potential multiple cropping index to reflect the potential sowing ability. The impacting mechanism, land use status and its surplus capacity are investigated as well. The main conclusions are as following; During 1949-2010, the agricultural land was the greatest in amount in the middle of China, followed by that in the country's eastern and western regions. The most rapid increase and decrease of agricultural land were observed in Xinjiang and North China respectively, Northwest China and South China is also changed rapid. The variation trend before 1980 differed significantly from that after 1980. Agricultural land was affected by both natural and social factors, such as regional climate and environmental changes, population growth, economic development, and implementation of policies. In this paper, the effects of temperature and urbanization on the coverage of agriculture land are evaluated, and the results show that the urbanization can greatly affects the amount of agriculture land in South China, Northeast China, Xinjiang and Southwest China. From 1980 to 2009, the extent of agricultural land use had increased as the surplus capacity had decreased. Still, large remaining potential space is available, but the future utilization of agricultural land should be carried out with scientific planning and management for the sustainable development.

Variability of onset and retreat of the rainy season in mainland China and associations with atmospheric circulation and sea surface temperature

Science.gov (United States)

Cao, Qing; Hao, Zhenchun; Shao, Quanxi; Hao, Jie; Nyima, Tsring

2018-02-01

Precipitation plays an important role in both environment and human society and is a significant factor in many scientific researches such as water resources, agriculture and climate impact studies. The onset and retreat of rainy season are useful features to understand the variability of precipitation under the influence of climate change. In this study, the characteristics of onset and retreat in mainland China are investigated. The multi-scale moving t-test was applied to determine rainy season and K-means cluster analysis was used to divide China into sub-regions to better investigate rainy season features. The possible linkage of changing characteristics of onset and retreat to climate factors were also explored. Results show that: (1) the onset started from middle March in the southeast of China to early June in the northwest and rainy season ended earliest in the northwest and southeast while the central China had the latest retreat; (2) Delayed onset and advanced retreat over time were observed in many parts of China, together with overall stable or increased rainy-season precipitation, would likely lead to higher probability of flooding; (3) The onset (retreat) was associated with the increased (decreased) number of cyclones in eastern China and anticyclone near the South China Sea. Delayed onset, and advanced retreat were likely related to cold and warm sea surface temperature (SST) in the conventional El Niño-Southern Oscillation (ENSO) regions, respectively. These results suggest that predictability of rainy season can be improved through the atmospheric circulation and SST, and help water resources management and agricultural planning.

Preliminary postclosure risk assessment: Yucca Mountain, Nevada, candidate repository site

International Nuclear Information System (INIS)

Eslinger, P.W.; Elwood, D.M.; Freshley, M.D.; Reimus, P.W.; Tanner, J.E.; Doctor, P.G.; Engel, D.W.; Liebetrau, A.M.; Strenge, D.L.; Van Luik, A.E.

1989-10-01

A study was conducted by the Pacific Northwest Laboratory for the US Department of Energy, Office of Civilian Radioactive Waste Management, to estimate the postclosure risk, in terms of population health effects, of a proposed high-level nuclear waste repository at Yucca Mountain, Nevada. The risk estimates cover a time span of 1 million years following repository closure. Representative disruptive and intrusive events were selected and evaluated in addition to expected conditions. The estimates were generated assuming spent fuel as the waste form and included all important nuclides from inventory, half-life and dose perspectives. The base case results yield an estimate of 36 health effects over the first million years of repository operation. The doses attributed to the repository corresponds to about 0.1 percent of the doses received from natural background radiation. 16 refs., 1 fig

Flash flood disasters analysis and evaluation: a case study of Yiyang County in China

Science.gov (United States)

Li, Haichen; Zhang, Xiaolei; Li, Qing; Qin, Tao; Lei, Xiaohui

2018-03-01

Global climate change leads to the more extreme precipitation and more flash flood disasters, which is a serious threat to the mountain inhabitants. To prevent flash flood disasters, China started flash flood disaster control planning and other projects from 2006. Among those measures, non-engineering measures are effective and economical. This paper introduced the framework of flash flood disaster analysis and evaluation in China, followed by a case study of Yiyang County.

[Species-area and species-abundance relationships of arthropod community in various vegetation restoration areas in Zhifanggou watershed, Shaanxi province of Northwest China].

Science.gov (United States)

Zhang, Feng; Hong, Bo; Li, Ying-Mei; Chen, Zhi-Jie; Zhang, Shu-Lian; Zhao, Hui-Yan

2013-02-01

Taking the Zhifanggou watershed in Ansai, Shaanxi Province of Northwest China as a study unit, an investigation on the arthropods in 8 forest stands was conducted from 2006 to 2008, with the species-area and species-abundance relationships of the arthropods in these stands analyzed by various mathematical models. In these forest stands, the species-area relationship of the arthropods accorded with the formula S= CAm With the increase of investigation area, the species number approached to a constant, and the corresponding smallest investigation area was in the order of natural bush > natural forest > Populus davidiana+Robinia pseudoacacia forest > Hippaphae rhamnoides +Caragana mocrophylla forest> Periploca sepium forest > Hippaphae rhamnoides forest > Robinia pseudoacacia forest > Caragana mocrophylla forest, indicating that the more complex the stands, the larger the minimum area needed to be investigated. Based on sampling investigation, the species-abundance models of the arthropods in various stands were established. Lognormal distribution model (LN) was most suitable to fit the arthropod community in natural recovery stands, suggesting that in the arthropod community, there were more species with medial individual amount and fewer abundant species and rare species, and no obvious dominant species. LogCauchy distribution model (LC) was most suitable to fit the arthropod community in mixed and pure stands. As compared with natural recovery stand, mixed and pure stands had more abundant and rare species, and more dominant species.

The first commercial spent fuel shipment in China

Energy Technology Data Exchange (ETDEWEB)

Meinert, N.M. [NAC International, Norcross, GA (United States); Xiaoqing Li [Everclean Environmental Engineering Corp., Beijing, BJ (China)

2004-07-01

In two and a half years, government regulatory agencies and contractors from three countries worked together to design, license, fabricate, and transport the first commercial spent fuel shipment in China. Their cooperative efforts helped avoid the loss of full core reserve at a nuclear power plant serving two of China's largest cities. In March 2001, Everclean Environmental Engineering Corporation (EEEC) selected NAC International (NAC) to supply two United States Nuclear Regulatory Commission (USNRC) licensed Storable Transport Casks (NACSTC) and technology support, to ensure that qualified Chinese operators would be ready to load the first cask in late 2003. EEEC is a subsidiary of China National Nuclear Corporation (CNNC), which sets nuclear policy in China. EEEC is responsible for implementing nuclear transportation policy set forth from its parent corporation. Timely implementation of EEEC's ambitious plan would avoid loss of full core reserve at Guangdong Nuclear Power Station (Daya Bay) Unit-1, which supplies power to Hong Kong and Schenzen. The spent fuel would be transported to the Lanzhou Nuclear Fuel Complex (LNFC), a reprocessing facility, approximately 4,000 kilometers Northwest of Daya Bay.

Pacific Northwest regional assessment program

International Nuclear Information System (INIS)

Anon.

1976-01-01

The Pacific Northwest (comprised of the states of Alaska, Idaho, Montana, Oregon, Washington and Wyoming) can by several measures be regarded as a national warehouse of fossil energy resources. This condition coupled with an evolving national policy stressing utilization of fossil fuels in the near term prior to development of more advanced technologies for energy supply, could result in the imposition of major changes in the region's environmental, socioeconomic and possibly health status. The objective of the Pacific Northwest Regional Assessment Program is to establish and exercise an integrated analytical assessment program for evaluation of these potential changes that may result from various energy development or conservation scenarios. After consideration of a variety of approaches to integrated assessment at a regional level, Pacific Northwest Laboratories (PNL) has concluded that dynamic simulation techniques provide the best available approach to evaluating the issues pertinent to the Northwest. As a result, the PNW Regional Assessment Program has been structured in a framework involving ten sectors. Each of these sectors involve their own submodels that receive information either from outside the model as exogenous inputs or from other sector submodels

Brief Communication: Landslides triggered by the M_s =7.0 Lushan earthquake, China

OpenAIRE

X. L. Chen; L. Yu; M. M. Wang; J. Y. Li

2013-01-01

Earthquake-triggered landslide has drawn much attention in the world because of severe hazards it causes. The Ms =7.0 Lushan earthquake which occurred on 20 April 2013, China, in the Longmen Shan mountain region triggered more than 1000 landslides and really blocked many roads and exacerbated the overall transportation problems in the mountainous region. Preliminary landslides inventory is complied based on the high-resolution remote sensing images. Based on it, ...

Changing stakeholder relationships in nature reserve management: a case study on Snake Island-Laotie Mountain National Nature Reserve, Liaoning, China.

Science.gov (United States)

Zhou, Dan; Wang, Ziyan; Lassoie, James; Wang, Xiaoping; Sun, Lixin

2014-12-15

The number and total area of nature reserves in China has increased rapidly over the past couple of decades; however, the ability to effectively manage these reserves has not kept pace and conflicts between conservation efforts and economic development have emerged. The Snake Island-Laotie Mountain National Nature Reserve (SILMNNR) currently is experiencing the challenges of balancing conservation with local community development. This paper uses components analysis of human ecosystems (HEC) to examine conflicts arising from the management of the nature reserve and uses a stakeholder analysis to identify and better understand stakeholder inter-relationships in the SILMNNR-HEC. The goal of this study is to identify critical factors influencing stakeholder relationships in order to find ways of relieving conflicts between the reserve management and development. The stakeholder analysis revealed that the key stakeholders in the SILMNNR-HEC are natural resources, the Liaoning SILMNNR Authority, local residents, and enterprise developers; however, there was unequal power among stakeholders in the decision making process affecting the nature reserve. The paper evaluated the conditions and processes of SILMNNR-HEC through a framework of stakeholder relationships where critical factors, such as policy, finance, technology, and labor, and their respective strengths and feedbacks among stakeholders, were assessed and showed unequal flows of power among stakeholders. Two approaches are provided for transforming the unbalanced relationships into a stable and sustainable framework to sustainably manage the nature reserve: the first is by changing stakeholder relationships from opposition to cooperation; and the second by enhancing feedbacks and dynamics among stakeholders. The analysis used in this paper can be used as a model to assess conflicts around other protected areas in China and elsewhere. Copyright © 2014 Elsevier Ltd. All rights reserved.

Migration and Morphology of Asymmetric Barchans in the Central Hexi Corridor of Northwest China

Directory of Open Access Journals (Sweden)

Zhengcai Zhang

2018-06-01

Full Text Available Crescent-shaped barchan dunes often display an asymmetric shape, with one limb longer than the other. As shown in previous studies, asymmetric bimodal winds constitute one major cause of barchan asymmetry, but the heterogeneous conditions of sand availability or flux, as well as topographic influences, may be also important. Understanding the morphology and dynamics of asymmetric barchans may have an impact in a broad range of areas, particularly as these dunes may serve as a proxy for planetary wind regimes and soil conditions in extraterrestrial environments. However, in addition to the existing theories and numerical models that explain barchan asymmetry, direct measurements of migration rates and morphologic changes of real asymmetric barchans over a time span of several years would be beneficial. Therefore, here we report such measurements, which we have acquired by investigating asymmetric barchans in the Hexi Corridor, northwest of China. We have found that dune interactions and asymmetric influx conditions are the most important causes of barchan asymmetry in this field. Particle size distributions in the Hexi Corridor display strong variations over different parts of the asymmetric barchans, as well as over different dunes, with gravel particles being incorporated from the substrate as the dunes migrate. Our observations have shown that upwind sediment sources are important for dune formation in the Hexi Corridor, and that interdune interactions affect dune shape in different ways, depending on their offset. The asymmetric barchans in the Hexi Corridor are active, with an average migration rate (MR between 8 and 53 m year−1, in spite of the different asymmetric shapes. Our data for dune migration rates can be described well by a scaling of MR = A/(W + W0, where W is the barchan cross-wind width, A ≈ 2835 m2 s−1, and W0 ≈ 44 m. A similar scaling fits very well the migration rate as a function of dune along-wind width L, (i.e., MR

Incentives needed for foreign participation on China's natural gas sector

International Nuclear Information System (INIS)

Logan, J.; Chandler, W.

1998-01-01

This article summarizes the results of a workshop organized by Battelle Memorial Institute's Pacific Northwest National Laboratory, July 31, 1997, to identify ways to expand natural gas use in China. The workshop was attended by representatives from four natural gas companies active in China, the US Department of Energy, and the Natural Resources Defense Council. To ensure a frank discussion, it was agreed that none of the companies' comments would be made for attribution. However, the companies attending were all major firms with deep commitments to China. The workshop resulted in recommendations to the Chinese government for boosting the exploration and development activities of these companies and to the US government for supporting those efforts. This paper includes a section which summarizes the recommendations that came out of the workshop. After describing the gas resource base, the paper discusses gas trade and drivers of greater natural gas use

Quantifying the effects of climate variability and human activities on runoff for Kaidu River Basin in arid region of northwest China

Science.gov (United States)

Chen, Zhongsheng; Chen, Yaning; Li, Baofu

2013-02-01

Much attention has recently been focused on the effects that climate variability and human activities have had on runoff. In this study, data from the Kaidu River Basin in the arid region of northwest China were analyzed to investigate changes in annual runoff during the period of 1960-2009. The nonparametric Mann-Kendall test and the Mann-Kendall-Sneyers test were used to identify trend and step change point in the annual runoff. It was found that the basin had a significant increasing trend in annual runoff. Step change point in annual runoff was identified in the basin, which occurred in the year around 1993 dividing the long-term runoff series into a natural period (1960-1993) and a human-induced period (1994-2009). Then, the hydrologic sensitivity analysis method was employed to evaluate the effects of climate variability and human activities on mean annual runoff for the human-induced period based on precipitation and potential evapotranspiration. In 1994-2009, climate variability was the main factor that increased runoff with contribution of 90.5 %, while the increasing percentage due to human activities only accounted for 9.5 %, showing that runoff in the Kaidu River Basin is more sensitive to climate variability than human activities. This study quantitatively distinguishes the effects between climate variability and human activities on runoff, which can do duty for a reference for regional water resources assessment and management.

Bacillus methylotrophicus Strain NKG-1, Isolated from Changbai Mountain, China, Has Potential Applications as a Biofertilizer or Biocontrol Agent.

Science.gov (United States)

Ge, Beibei; Liu, Binghua; Nwet, Thinn Thinn; Zhao, Wenjun; Shi, Liming; Zhang, Kecheng

2016-01-01

Chemical pesticides are widely used in agriculture, which endangers both environmental health and food safety. Biocontrol is an environmentally-friendly and cost-effective green technique in environmental protection and agricultural production; it generally uses selected bioresources, including beneficial microorganisms. We isolated a novel bacterial strain (NKG-1) from the rare dormant volcanic soils of Changbai Mountain in China's Jilin Province. The strain was identified as Bacillus methylotrophicus using morphological, biochemical, physiological, and phylogenetic 16S rDNA sequencing data. This strain was able to suppress mycelial growth and conidial germination of numerous plant pathogenic fungi on solid media. A greenhouse experiment showed that application of NKG-1 fermentation broth prior to inoculation of Botrytis cinerea, the cause of gray tomato mold, inhibited growth of the mold by 60%. Furthermore, application of a 100× dilution of NKG-1 fermentation broth to tomato seedlings yielded a significant increase in seedling fresh weight (27.4%), seedling length (12.5%), and root length (57.7%) compared to the control. When the same dosage was applied in the field, we observed increases in tomato plant height (14.7%), stem diameter (12.7%), crown width (16.3%), and maximum fruit diameter (11.5%). These results suggest that NKG-1 has potential commercial application as a biofertilizer or biocontrol agent.

Effects of permafrost thaw on carbon emissions under aerobic and anaerobic environments in the Great Hing'an Mountains, China.

Science.gov (United States)

Song, Changchun; Wang, Xianwei; Miao, Yuqing; Wang, Jiaoyue; Mao, Rong; Song, Yanyu

2014-07-15

The carbon (C) pool of permafrost peatland is very important for the global C cycle. Little is known about how permafrost thaw could influence C emissions in the Great Hing'an Mountains of China. Through aerobic and anaerobic incubation experiments, we studied the effects of permafrost thaw on CH4 and CO2 emissions. The rates of CH4 and CO2 emissions were measured at -10, 0 and 10°C. Although there were still C emissions below 0°C, rates of CH4 and CO2 emissions significantly increased with permafrost thaw under aerobic and anaerobic conditions. The C release under aerobic conditions was greater than under anaerobic conditions, suggesting that permafrost thaw and resulting soil environment change should be important influences on C emissions. However, CH4 stored in permafrost soils could affect accurate estimation of CH4 emissions from microbial degradation. Calculated Q10 values in the permafrost soils were significantly higher than values in active-layer soils under aerobic conditions. Our results highlight that permafrost soils have greater potential decomposability than soils of the active layer, and such carbon decomposition would be more responsive to the aerobic environment. © 2013 Elsevier B.V. All rights reserved.

Monitoring of volatile organic compounds (VOCs) from an oil and gas station in northwest China for 1 year

Science.gov (United States)

Zheng, Huang; Kong, Shaofei; Xing, Xinli; Mao, Yao; Hu, Tianpeng; Ding, Yang; Li, Gang; Liu, Dantong; Li, Shuanglin; Qi, Shihua

2018-04-01

Oil and natural gas are important for energy supply around the world. The exploring, drilling, transportation and processing in oil and gas regions can release a lot of volatile organic compounds (VOCs). To understand the VOC levels, compositions and sources in such regions, an oil and gas station in northwest China was chosen as the research site and 57 VOCs designated as the photochemical precursors were continuously measured for an entire year (September 2014-August 2015) using an online monitoring system. The average concentration of total VOCs was 297 ± 372 ppbv and the main contributor was alkanes, accounting for 87.5 % of the total VOCs. According to the propylene-equivalent concentration and maximum incremental reactivity methods, alkanes were identified as the most important VOC groups for the ozone formation potential. Positive matrix factorization (PMF) analysis showed that the annual average contributions from natural gas, fuel evaporation, combustion sources, oil refining processes and asphalt (anthropogenic and natural sources) to the total VOCs were 62.6 ± 3.04, 21.5 ± .99, 10.9 ± 1.57, 3.8 ± 0.50 and 1.3 ± 0.69 %, respectively. The five identified VOC sources exhibited various diurnal patterns due to their different emission patterns and the impact of meteorological parameters. Potential source contribution function (PSCF) and concentration-weighted trajectory (CWT) models based on backward trajectory analysis indicated that the five identified sources had similar geographic origins. Raster analysis based on CWT analysis indicated that the local emissions contributed 48.4-74.6 % to the total VOCs. Based on the high-resolution observation data, this study clearly described and analyzed the temporal variation in VOC emission characteristics at a typical oil and gas field, which exhibited different VOC levels, compositions and origins compared with those in urban and industrial areas.

Model identification and control of development of deeply buried paleokarst reservoir in the central Tarim Basin, northwest China

Science.gov (United States)

Yu, Jingbo; Li, Zhong; Yang, Liu; Han, Yinxue

2018-04-01

The paleokarst reservoirs of the Ordovician Yingshan formation, rich in oil and gas, are deeply buried in the central Tarim Basin, northwest China. Dozens of imaging well-logs in this region reveal five typical paleokarst features, including solution vugs, solution-enlarged fractures, filled caves, unfilled caves and collapsed caves, as well as two typical paleokarst structures located in different paleotopographic sites, including paleokarst vadose and phreatic zones. For seismic data, the large wave impedance contrast between the paleocave system and the surrounding rocks leads to a strong seismic reflection, which is highlighted as a bead-like ‘bright spot’ in a seismic section. By quantitatively estimating the seismic resolution limits of deep seismic reflections, a single paleocave cannot be identified from a seismic profile, and the bead-like reflection represents an entire paleocave complex. The spectral decomposition technique was employed to depict the planar shape and semi-quantitatively measure the size of the paleocave complexes. The results indicate that the sizes of the paleokarst caves are all small, and most of the karst caves are nearly completely filled by clay and calcite. The small cave size and the effective support of cave fills for the overlying strata mean that some individual paleocaves in a paleocave complex are preserved at a burial depth of more than 6000 m. Paleotopography and faults strongly impact the distribution of paleokarst reservoirs. Well-developed paleokarst reservoirs are generally located in paleotopographic highlands and on slopes, and for a specific paleotopographic site, the distribution of paleokarst reservoirs is obviously controlled by NW-SE trending faults. The most favorable area for paleokarst development is the Tazhong No. 10 fault zone, a faulted anticline bounded by two NW-SE trending back thrusts.

Impact of anthropogenic emissions and open biomass burning on regional carbonaceous aerosols in South China

Energy Technology Data Exchange (ETDEWEB)

Zhang Gan, E-mail: zhanggan@gig.ac.c [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Li Jun [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Li Xiangdong [Department of Civil and Structural Engineering, Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong); Xu Yue; Guo Lingli [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Tang Jianhui [Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003 (China); Lee, Celine S.L. [Department of Civil and Structural Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong); Liu Xiang [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Chen Yingjun [Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003 (China)

2010-11-15

Carbonaceous aerosols were studied at three background sites in south and southwest China. Hok Tsui in Hong Kong had the highest concentrations of carbonaceous aerosols (OC = 8.7 {+-} 4.5 {mu}g/m{sup 3}, EC = 2.5 {+-} 1.9 {mu}g/m{sup 3}) among the three sites, and Jianfeng Mountains in Hainan Island (OC = 5.8 {+-} 2.6 {mu}g/m{sup 3}, EC = 0.8 {+-} 0.4 {mu}g/m{sup 3}) and Tengchong mountain over the east edge of the Tibetan Plateau (OC = 4.8 {+-} 4.0 {mu}g/m{sup 3}, EC = 0.5 {+-} 0.4 {mu}g/m{sup 3}) showed similar concentration levels. Distinct seasonal patterns with higher concentrations during the winter, and lower concentrations during the summertime were observed, which may be caused by the changes of the regional emissions, and monsoon effects. The industrial and vehicular emissions in East, Southeast and South China, and the regional open biomass burning in the Indo-Myanmar region of Asia were probably the two major potential sources for carbonaceous matters in this region. - Anthropogenic emissions in China and open biomass burning in the Indo-Myanmar region were the two major potential sources for carbonaceous matters in South China region.

Impact of anthropogenic emissions and open biomass burning on regional carbonaceous aerosols in South China

International Nuclear Information System (INIS)

Zhang Gan; Li Jun; Li Xiangdong; Xu Yue; Guo Lingli; Tang Jianhui; Lee, Celine S.L.; Liu Xiang; Chen Yingjun

2010-01-01

Carbonaceous aerosols were studied at three background sites in south and southwest China. Hok Tsui in Hong Kong had the highest concentrations of carbonaceous aerosols (OC = 8.7 ± 4.5 μg/m 3 , EC = 2.5 ± 1.9 μg/m 3 ) among the three sites, and Jianfeng Mountains in Hainan Island (OC = 5.8 ± 2.6 μg/m 3 , EC = 0.8 ± 0.4 μg/m 3 ) and Tengchong mountain over the east edge of the Tibetan Plateau (OC = 4.8 ± 4.0 μg/m 3 , EC = 0.5 ± 0.4 μg/m 3 ) showed similar concentration levels. Distinct seasonal patterns with higher concentrations during the winter, and lower concentrations during the summertime were observed, which may be caused by the changes of the regional emissions, and monsoon effects. The industrial and vehicular emissions in East, Southeast and South China, and the regional open biomass burning in the Indo-Myanmar region of Asia were probably the two major potential sources for carbonaceous matters in this region. - Anthropogenic emissions in China and open biomass burning in the Indo-Myanmar region were the two major potential sources for carbonaceous matters in South China region.

Quantification of Environmental Flow Requirements to Support Ecosystem Services of Oasis Areas: A Case Study in Tarim Basin, Northwest China

Directory of Open Access Journals (Sweden)

Jie Xue

2015-10-01

Full Text Available Recently, a wide range of quantitative research on the identification of environmental flow requirements (EFRs has been conducted. However, little focus is given to EFRs to maintain multiple ecosystem services in oasis areas. The present study quantifies the EFRs in oasis areas of Tarim Basin, Xinjiang, Northwest China on the basis of three ecosystem services: (1 maintenance of riverine ecosystem health, (2 assurance of the stability of oasis–desert ecotone and riparian (Tugai forests, and (3 restoration of oasis–desert ecotone groundwater. The identified consumptive and non-consumptive water requirements are used to quantify and determine the EFRs in Qira oasis by employing the summation and compatibility rules (maximum principle. Results indicate that the annual maximum, medium, and minimum EFRs are 0.752 × 108, 0.619 × 108, and 0.516 × 108 m3, respectively, which account for 58.75%, 48.36%, and 40.29% of the natural river runoff. The months between April and October are identified as the most important periods to maintain the EFRs. Moreover, the water requirement for groundwater restoration of the oasis–desert ecotone accounts for a large proportion, representing 48.27%, 42.32%, and 37.03% of the total EFRs at maximum, medium, and minimum levels, respectively. Therefore, to allocate the integrated EFRs, focus should be placed on the water demand of the desert vegetation’s groundwater restoration, which is crucial for maintaining desert vegetation to prevent sandstorms and soil erosion. This work provides a reference to quantify the EFRs of oasis areas in arid regions.

Epic landslide erosion from mountain roads in Yunnan, China – challenges for sustainable development

Science.gov (United States)

Expanding systems of mountain roads in developing countries significantly increase the risk of landslides and sedimentation in streams and rivers, as well as create vulnerabilities for residents and aquatic resources. However, neither government agencies nor external assistance o...

Geothermal constraints on enrichment of boron and lithium in salt lakes: An example from a river-salt lake system on the northern slope of the eastern Kunlun Mountains, China

Science.gov (United States)

Tan, Hongbing; Chen, Jun; Rao, Wenbo; Zhang, Wenjie; Zhou, Huifang

2012-06-01

Some rivers on the northern slope of the eastern Kunlun Mountains in the Qaidam Basin, China, show very high concentrations of boron and lithium. Correspondingly, the salt lakes fed by these rivers show an unusual enrichment of boron and lithium, and become an important economic resource. The origin of boron and lithium has long been debated. The aim of this study is to analyze the water chemistry and hydrogen and oxygen isotopic composition of river water to understand the unusual enrichment of boron and lithium in the salt lakes of the Qaidam Basin. Oxygen and hydrogen isotope data show that the source of river water in the winter and summer originates from the Kunlun Mountain ice and snow melt water, respectively. The water chemistry shows that boron and lithium contents are high but little variable with seasons in the Nalenggele River and Wutumeiren River waters. By contrast, other rivers have much lower lithium and boron contents. Moreover, the contents of B3+ and Li+ in the river loads or bed sands show little difference amongst the rivers. This indicates that removal by adsorption or input by surface rock weathering is not the main controlling factor of the B3+ and Li+ variation in the rivers. Rivers with high B3+ and Li+ content are chemically similar to geothermal waters in the Tibetan Plateau. In addition, the source area of the Nalenggele River is located in a collision zone of the Kunlun Mountains and Altun Mountains. Large and deep faults can serve as conduits for geothermal fluids. Thus, deep geothermal waters in the source area can easily migrate to the surface and discharge as springs feeding the rivers. They are an important source of B3+ and Li+ to the rivers. The abnormally high contents of B3+ and Li+ in the Nalenggele and Wutumeiren Rivers also suggest that the geothermal source area may be a future target for boron and lithium resources.

Influence of the Farmer’s Livelihood Assets on Livelihood Strategies in the Western Mountainous Area, China

Directory of Open Access Journals (Sweden)

Zhifei Liu

2018-03-01

Full Text Available The livelihood strategies of farm households depend on the conditions of their assets, and farm households cope with risks and shocks through portfolios consisting of different types of assets. Thus, discussing the relationship between the livelihood assets and the livelihood strategies of farm households helps in understanding their livelihood conditions and in formulating reasonable poverty reduction policies. Taking Zunyi City, which is located in a western, mountainous area of China, as the study region and using the framework of sustainability analysis, this study first tries to establish the mechanism of the influence of farm household livelihood assets on livelihood strategies, then evaluates different farm household livelihood assets by establishing an evaluation index system for them, and finally conducts an empirical analysis on the influence of farm household livelihood assets on livelihood strategies using a multinomial logit model. The research results indicate the following: (1 natural assets and material assets have a significant negative influence on farm households’ choice of livelihood strategies, that is, the more natural assets and material assets that farm households own, the more likely they are to choose livelihood strategies involving engaging in agricultural production; (2 Manpower assets and financial assets have a significant positive influence on farm households’ choice of livelihood strategy, namely, the more manpower assets and financial assets that farm households own, the more likely they are to choose livelihood strategies involving engaging in non-agricultural production; (3 Social assets have no significant influence on farm households’ choice of livelihood strategy.

Influence of shrubs on soil chemical properties in Alxa desert steppe, China

Science.gov (United States)

Hua Fu; Shifang Pei; Yaming Chen; Changgui Wan

2007-01-01

Alxa desert steppe is one of severely the degraded rangelands in the Northwest China. Shrubs, as the dominant life form in the desert steppe, play an important role in protecting this region from further desertification. Chemical properties of three soil layers (0 to 10, 10 to 20 and 20 to 30 cm) at three locations (the clump center [A], in the periphery of shrub...

[Pollution and Potential Ecology Risk Evaluation of Heavy Metals in River Water, Top Sediments on Bed and Soils Along Banks of Bortala River, Northwest China].

Science.gov (United States)

Zhang, Zhao-yong; Abuduwaili, Jilili; Jiang, Feng-qing

2015-07-01

This paper focuses on the sources, pollution status and potential ecology risks of heavy metals (Cr, Cu, Hg, As, Cd, Pb, and Zn) in the surface water, top sediment of river bed and soil along banks of Bortala River, which locates in the oasis region of Xinjiang, northwest China. Results showed that: (1) As a whole, contents of 7 tested heavy metals of Bortala River were low, while the maximum values of Hg, Cd, Pb, and Cr in the river water were significantly higher than those of Secondary Category of the Surface Water Quality Standards of People's Republic of China (GB 3838-2002) and Drinking Water Guideline from WHO. Analysis showed that the heavy metals contents of top sediment on river bed and soils along river banks were significantly higher than those of the river water. (Correlation analysis and enrichment factor (EF) calculation showed that in the river water, top sediment on river bed and soils along river banks, Hg, Cd, Pb, and Cr mainly originated from industrial emissions, urban and rural anthropogenic activities, transportation and agricultural production activities; While Cu, Zn, and As mainly originated from natural geological background and soil parent materials. (3) Pollution assessment showed that in three matrices, the single factor pollution index(Pi) and the integrated pollution index (Pz) of 7 heavy metals were all lower than 1, and they all belonged to safe and clean levels. (4) Potential ecology risk evaluation showed that as a whole the single factor potential ecological risk (Eir) and the integrated potential ecology risks (RI) of 7 heavy metals were relatively low, and would not cause threats to the health of water and soil environment of river basin, while the potential ecology risks of Cd, Hg, Pb, and Cr were significantly higher than those of other heavy metals.

7 CFR 319.8-13 - From Northwest Mexico.

Science.gov (United States)

2010-01-01

... 7 Agriculture 5 2010-01-01 2010-01-01 false From Northwest Mexico. 319.8-13 Section 319.8-13... for the Entry of Cotton and Covers from Mexico § 319.8-13 From Northwest Mexico. Contingent upon continued freedom of Northwest Mexico and of the West Coast of Mexico from infestations of the pink bollworm...

MANAGEMENT OF RADIOACTIVE WASTES IN CHINA

Institute of Scientific and Technical Information of China (English)

潘自强

1994-01-01

The policy and principles on management of radioactive wastes are stipulated.Cement solidification and bituminization unit has come into trial run.Solid radioactive waste is stored in tentative storage vault built in each of nuclear facilities.Seventeen storages associated with applications of nuclear technology and radioisotopes have been built for provinces.Disposal of low and intermediate level radioactive wastes pursues the policy of “regional disposal”.Four repositories have been planned to be built in northwest.southwest,south and east China respectively.A program for treatment and disposal of high level radioactive waste has been made.

Tree competition and species coexistence in a Quercus--Betula forest in the Dongling Mountains in northern China

Science.gov (United States)

Hou, Ji-hua; Mi, Xiang-cheng; Liu, Can-ran; Ma, Ke-ping

2006-09-01

The population size structure, growth dynamics and mode of competition among adult trees (≥ 4 cm DBH) of six abundant tree species in a 5 ha study plot of a temperate deciduous forest in the Dongling Mountains in northern China were investigated using diffusion and growth dynamics models. In the year of 2000, two dominant species, Quercus liaotungensis and Betula dahurica accounted for ca. 68.69% of the total basal area and 52.71% of the total density of adult plants. Q. liaotungensis, Populus davidiana and Acer mono exhibited inverse J-shaped DBH distributions whereas Betula dahurica, B. platyphylla and Salix caprea had unimodal DBH distributions. One-sided interspecific competition was detected between some species combinations at the scale of the 5 ha study plot, and the competitive effect was mainly size-dependent rather than from species-specific interactions with large individuals in the canopy layer out competing smaller individuals in the understory. Symmetric competition was found between Q. liaotungensis and A. mono only. However, considering the straight line relationship of G ( t, x) - √{D(t, x)}, which suggests that competitive asymmetry is very low or absent, combined with the relatively low mortality of trees with a DBH larger than 4 cm, we speculate that asymmetric interspecific competition was not important in structuring this tree community. Regeneration characteristics of each species are most likely important in regulating species coexistence and stand dynamics in this forest.

Different trends in extreme and median surface aerosol extinction coefficients over China inferred from quality-controlled visibility data

Science.gov (United States)

Li, Jing; Li, Chengcai; Zhao, Chunsheng

2018-03-01

Although the temporal changes in aerosol properties have been widely investigated, the majority of studies has focused on average conditions without much emphasis on the extremes. However, the latter can be more important in terms of human health and climate change. This study uses a previously validated, quality-controlled visibility dataset to investigate the long-term trends (expressed in terms of relative changes) in extreme surface aerosol extinction coefficient (AEC) over China and compares them with the median trends. Two methods are used to independently evaluate the trends, which arrive at consistent results. The signs of extreme and median trends are generally coherent, whereas their magnitudes show distinct spatial and temporal differences. In the 1980s, an overall positive trend is found throughout China with the extreme trend exceeding the mean trend, except for northwest China and the North China Plain. In the 1990s, AEC over northeast and northwest China started to decline while the rest of the country still exhibited an increase. The extreme trends continued to dominate in the south while they yielded to the mean trend in the north. After the year 2000, the extreme trend became weaker than the mean trend overall in terms of both the magnitude and significance level. The annual trend can be primarily attributed to winter and fall trends. The results suggest that the decadal changes in pollution in China may be governed by different mechanisms. Synoptic conditions that often result in extreme air quality changes might have dominated in the 1980s, whereas emission increase might have been the main factor for the 2000s.

Epidemiology of gastroesophageal reflux disease: A general population-based study in Xi’an of Northwest China

OpenAIRE

Wang, Jin-Hai; Luo, Jin-Yan; Dong, Lei; Gong, Jun; Tong, Ming

2004-01-01

AIM: Gastroesophageal reflux disease (GERD) is a common disorder in the Western population, but detailed population-based data in China are limited. The aim of this study was to understand the epidemiology of symptomatic gastroesophageal reflux (SGER) in adults of Xi’an, a northwestern city of China, and to explore the potential risk factors of GERD.

Recent population trends of mountain goats in the Olympic Mountains, Washington

Science.gov (United States)

Jenkins, Kurt J.; Happe, Patricia J.; Beirne, Katherine F.; Hoffman, Roger A.; Griffin, Paul C.; Baccus, William T.; Fieberg, John

2012-01-01

Mountain goats (Oreamnos americanus) were introduced in Washington's Olympic Mountains during the 1920s. The population subsequently increased in numbers and expanded in range, leading to concerns by the 1970s over the potential effects of non-native mountain goats on high-elevation plant communities in Olympic National Park. The National Park Service (NPS) transplanted mountain goats from the Olympic Mountains to other ranges between 1981 and 1989 as a means to manage overabundant populations, and began monitoring population trends of mountain goats in 1983. We estimated population abundance of mountain goats during 18–25 July 2011, the sixth survey of the time series, to assess current population status and responses of the population to past management. We surveyed 39 sample units, comprising 39% of the 59,615-ha survey area. We estimated a population of 344 ± 72 (90% confidence interval [CI]) mountain goats in the survey area. Retrospective analysis of the 2004 survey, accounting for differences in survey area boundaries and methods of estimating aerial detection biases, indicated that the population increased at an average annual rate of 4.9% since the last survey. That is the first population growth observed since the cessation of population control measures in 1990. We postulate that differences in population trends observed in western, eastern, and southern sections of the survey zone reflected, in part, a variable influence of climate change across the precipitation gradient in the Olympic Mountains.

Is air pollution causing landslides in China?

Science.gov (United States)

Zhang, Ming; McSaveney, Mauri J.

2018-01-01

Air pollution in China often exceeds "unhealthy" levels, but Chinese air is not only a threat from being breathed: the pollutants may also be causing fatal landslides. Very acid rain from severe air pollution falls widely in southwest China, where coal is a major energy source. We discuss where acid rain may provide an unsuspected link between mining and the fatal 2009 Jiweishan landslide in southwest China; it may have reduced the strength of a thin, calcareous, black sapropelic shale in Jiweishan Mountain by removing cementing carbonate minerals and sapropel matrix. Mining beneath the potential slide mass may not have directly triggered the landslide, but collapse of abandoned adits drained a perched aquifer above a regional black-shale aquiclude. Inflow of acid, oxygenated water and nutrients into the aquiclude may have accelerated the reduction of strength of the weakest rocks and consequently led to rapid sliding of a large rock mass on a layer of weathered shale left composed largely of soft, and slippery talc.

Taking the pulse of mountains: Ecosystem responses to climatic variability

Science.gov (United States)

Fagre, Daniel B.; Peterson, David L.; Hessl, Amy E.

2003-01-01

An integrated program of ecosystem modeling and field studies in the mountains of the Pacific Northwest (U.S.A.) has quantified many of the ecological processes affected by climatic variability. Paleoecological and contemporary ecological data in forest ecosystems provided model parameterization and validation at broad spatial and temporal scales for tree growth, tree regeneration and treeline movement. For subalpine tree species, winter precipitation has a strong negative correlation with growth; this relationship is stronger at higher elevations and west-side sites (which have more precipitation). Temperature affects tree growth at some locations with respect to length of growing season (spring) and severity of drought at drier sites (summer). Furthermore, variable but predictable climate-growth relationships across elevation gradients suggest that tree species respond differently to climate at different locations, making a uniform response of these species to future climatic change unlikely. Multi-decadal variability in climate also affects ecosystem processes. Mountain hemlock growth at high-elevation sites is negatively correlated with winter snow depth and positively correlated with the winter Pacific Decadal Oscillation (PDO) index. At low elevations, the reverse is true. Glacier mass balance and fire severity are also linked to PDO. Rapid establishment of trees in subalpine ecosystems during this century is increasing forest cover and reducing meadow cover at many subalpine locations in the western U.S.A. and precipitation (snow depth) is a critical variable regulating conifer expansion. Lastly, modeling potential future ecosystem conditions suggests that increased climatic variability will result in increasing forest fire size and frequency, and reduced net primary productivity in drier, east-side forest ecosystems. As additional empirical data and modeling output become available, we will improve our ability to predict the effects of climatic change

Northwest Territories Power Corporation annual report 1991/92

International Nuclear Information System (INIS)

1992-06-01

The Northwest Territories Power Corporation is a crown corporation of the government of the Northwest Territories. The Corporation operates diesel and hydroelectric production facilities to provide utility services on a self-sustaining basis in the Northwest Territories. Total revenue for 1991/92 amounted to $92,872,000 with $84,954,000 coming from the sale of power. Financial statements are presented. 3 figs

Northwest Territories Power Corporation annual report 1992/93

International Nuclear Information System (INIS)

1993-06-01

The Northwest Territories Power Corporation is a crown corporation of the government of the Northwest Territories. The Corporation operates diesel and hydroelectric production facilities to provide utility services on a self-sustaining basis in the Northwest Territories. Total revenue for 1992/93 amounted to $98,327,000 with $90,274,000 coming from the sale of power. Financial statements are presented. 3 figs

Delimiting communities in the Pacific Northwest.

Science.gov (United States)

Ellen M. Donoghue

2003-01-01

The paper presents an approach for delimiting communities in the Northwest Forest Plan (NWFP) region of the Pacific Northwest that responds to the need to assess impacts and issues associated with broad-scale ecosystem management. Census block groups are aggregated to provide an alternative to more commonly used geographic delimitations of communities, specifically...

Characterization of primary geochemical haloes for gold exploration at the Huanxiangwa gold deposit, China

NARCIS (Netherlands)

Wang, Changming; Carranza, E.J.M; Zhang, Shouting; Zhang, Jing; Liu, Xiaoji Liu; Zhang, Da; Sun, Xiang; Duan, Cunji

2013-01-01

Recognition of primary geochemical haloes is one of the most important tools for exploring undiscovered mineral resources. This tool is being routinely applied in exploration programs at the Huanxiangwa gold deposit, Xiong'er Mountains, China. Sampling of unweathered rock for multi-element analysis

Wandering saints : Chan eccentrics in the art and culture of Song and Yuan China

NARCIS (Netherlands)

Paul, Paramita

2009-01-01

In Chinese history, few personalities compare to the Chan eccentrics. These legendary, exceptional monks, including the friends Hanshan and Shide, their teacher Fenggan, and Budai, supposedly dwelled in the mountains and cities of southeast China between the seventh and tenth centuries. Dressed in

Climate, Air Quality, and Human Health Benefits of Various Solar Photovoltaic Development Scenarios in China in 2030

Science.gov (United States)

Yang, J.; Mauzerall, D. L.; Wagner, F.; Li, X.

2016-12-01

Solar photovoltaic (PV) technology can greatly reduce both air pollution and GHG emissions from the power sector. The Chinese government has plans to scale up solar PV installation between now and 2030. However, there is little analysis of how deployment strategies will influence the range of benefits. Here we conduct the first integrated assessment study that quantifies the climate, air quality, and related human health benefits of various solar PV development strategies in 2030 China. Our results indicate that both the location of PV deployment, which coal power plants are replaced, and the extent of inter-provincial transmission greatly influence the co-benefits. We compare CO2 and PM2.5 reductions from two PV installation scenarios both with the 2030 government target of 400 GW national installed capacity. First, we assume all solar PV is utilized within the province in which it is generated and that it can not exceed 30% of total provincial electricity generation. We find that deploying more solar PV in locations near load centers via distributed PV systems has larger benefits and could lead to approximately 20,500 (between 8000 - 32,400, high and low bounds) annual avoided premature deaths, 15% more than building utility-scale solar PV plants in the sunny, yet sparsely populated northwest. The difference occurs because in the northwest a lower population and cleaner air leads to smaller reductions in air pollution related premature mortalities. Also greater potential for PV curtailment exists in the west. In terms of CO2 reduction, deploying PV near load centers leads to 12% greater reductions in CO2 emissions from the power sector - approximately 5% of China's total CO2 emission in 2030. Second, we enable inter-provincial transmission of PV electricity within each of China's six regional grids which allows greater use of abundant sunlight in the northwest. Our results for 2030 show that by expanding to the regional grid, curtailment rates in the northwest

Advances in global mountain geomorphology

Science.gov (United States)

Slaymaker, Olav; Embleton-Hamann, Christine

2018-05-01

Three themes in global mountain geomorphology have been defined and reinforced over the past decade: (a) new ways of measuring, sensing, and analyzing mountain morphology; (b) a new emphasis on disconnectivity in mountain geomorphology; and (c) the emergence of concerns about the increasing influence of anthropogenic disturbance of the mountain geomorphic environment, especially in intertropical mountains where population densities are higher than in any other mountain region. Anthropogenically induced hydroclimate change increases geomorphic hazards and risks but also provides new opportunities for mountain landscape enhancement. Each theme is considered with respect to the distinctiveness of mountain geomorphology and in relation to important advances in research over the past decade. The traditional reliance on the high energy condition to define mountain geomorphology seems less important than the presence of unique mountain landforms and landscapes and the distinctive ways in which human activity and anthropogenically induced hydroclimate change are transforming mountain landscapes.

Preliminary gravity and magnetic models across Midway Valley and Yucca Wash, Yucca Mountain, Nevada

International Nuclear Information System (INIS)

Ponce, D.A.; Langenheim, V.E.

1994-01-01

Detailed gravity and ground magnetic data collected along ten traverses across Midway Valley and Yucca Wash on the eastern flank of Yucca Mountain in southwest Nevada are interpreted. These data were collected as part of an effort to evaluate faulting in the vicinity of proposed surface facilities for a potential nuclear waste repository at Yucca Mountain. Geophysical data show that Midway Valley is bounded by large gravity and magnetic anomalies associated with the Bow Ridge and Paintbrush Canyon faults, on the west side of Exile Hill and on the west flank of Fran Ridge, respectively. In addition, Midway Valley itself is characterized by a number of small-amplitude anomalies that probably reflect small-scale faulting beneath Midway Valley. Gravity and magnetic data across the northwest trending Yucca Wash and the inferred Yucca Wash fault indicate no major vertical offsets greater than 100 m using a density contrast of 0.2 to 0.3 g/cm 3 along the proposed Yucca Wash fault. In addition, a broad magnetic high coincides with the approximate location of the hydrologic gradient and probably reflects moderately magnetic Topopah Spring Tuff or lavas in the Calico Hills Formation

Reconnaissance geologic map of the Dubakella Mountain 15 quadrangle, Trinity, Shasta, and Tehama Counties, California