The 2010-2015 megadrought in central Chile: impacts on regional hydroclimate and vegetation

Science.gov (United States)

Garreaud, René D.; Alvarez-Garreton, Camila; Barichivich, Jonathan; Boisier, Juan Pablo; Christie, Duncan; Galleguillos, Mauricio; LeQuesne, Carlos; McPhee, James; Zambrano-Bigiarini, Mauricio

2017-12-01

Since 2010 an uninterrupted sequence of dry years, with annual rainfall deficits ranging from 25 to 45 %, has prevailed in central Chile (western South America, 30-38° S). Although intense 1- or 2-year droughts are recurrent in this Mediterranean-like region, the ongoing event stands out because of its longevity and large extent. The extraordinary character of the so-called central Chile megadrought (MD) was established against century long historical records and a millennial tree-ring reconstruction of regional precipitation. The largest MD-averaged rainfall relative anomalies occurred in the northern, semi-arid sector of central Chile, but the event was unprecedented to the south of 35° S. ENSO-neutral conditions have prevailed since 2011 (except for the strong El Niño in 2015), contrasting with La Niña conditions that often accompanied past droughts. The precipitation deficit diminished the Andean snowpack and resulted in amplified declines (up to 90 %) of river flow, reservoir volumes and groundwater levels along central Chile and westernmost Argentina. In some semi-arid basins we found a decrease in the runoff-to-rainfall coefficient. A substantial decrease in vegetation productivity occurred in the shrubland-dominated, northern sector, but a mix of greening and browning patches occurred farther south, where irrigated croplands and exotic forest plantations dominate. The ongoing warming in central Chile, making the MD one of the warmest 6-year periods on record, may have also contributed to such complex vegetation changes by increasing potential evapotranspiration. We also report some of the measures taken by the central government to relieve the MD effects and the public perception of this event. The understanding of the nature and biophysical impacts of the MD helps as a foundation for preparedness efforts to confront a dry, warm future regional climate scenario.

Triassic volcanic units in coastal region of Antofagasta, northern Chile

International Nuclear Information System (INIS)

Basso, M.; Cortes, J.A.; Marinovic, N

2001-01-01

U-Pb geochronological evidence of a Middle to Late Triassic volcanic event was found in the coastal region of Antofagasta, northern Chile (23 o -23 o 30 ). Two new ages were obtained from rhyolitic tuffs and an associated dome, which have classically been attributed to the Jurassic La Negra Formation (au)

A New, Continuous 5400 Yr-long Paleotsunami Record from Lake Huelde, Chiloe Island, South Central Chile.

Science.gov (United States)

Kempf, P.; Moernaut, J.; Vandoorne, W.; Van Daele, M. E.; Pino, M.; Urrutia, R.; De Batist, M. A. O.

2014-12-01

After the last decade of extreme tsunami events with catastrophic damage to infrastructure and a horrendous amount of casualties, it is clear that more and better paleotsunami records are needed to improve our understanding of the recurrence intervals and intensities of large-scale tsunamis. Coastal lakes (e.g. Bradley Lake, Cascadia; Kelsey et al., 2005) have the potential to contain long and continuous sedimentary records, which is an important asset in view of the centennial- to millennial-scale recurrence times of great tsunami-triggering earthquakes. Lake Huelde on Chiloé Island (42.5°S), Chile, is a coastal lake located in the middle of the Valdivia segment, which is known for having produced the strongest ever instrumentally recorded earthquake in 1960 AD (MW: 9.5), and other large earthquakes prior to that: i.e. 1837 AD, 1737 AD (no report of a tsunami) and 1575 AD (Lomnitz, 1970, 2004, Cisternas et al., 2005). We present a new 5400 yr-long paleotsunami record with a Bayesian age-depth model based on 23 radiocarbon dates that exceeds all previous paleotsunami records from the Valdivia segment, both in terms of length and of continuity. 18 events are described and a semi-quantitative measure of the event intensity at the study area is given, revealing at least two predecessors of the 1960 AD event in the mid to late Holocene that are equal in intensity. The resulting implications from the age-depth model and from the semi-quantitative intensity reconstruction are discussed in this contribution.

Geotourizm marketing in Lake Constance’ region

Directory of Open Access Journals (Sweden)

Daniel Gerner

2009-09-01

Full Text Available Aim of this work is to evaluate factors responsible for these developments and to show chances for other regions by adopting thismarketing strategy. Besides marketing, interaction of tourism, industry and state was important. Many reasons can be found that shouldresult in a worse development of the region around the Lake of Constance . But instead, today this region has a higher populationgrowth than the average of Baden-Württemberg and is the best economic region outside of urban centers. Scientists spoke aboutan overheated economic growth during the last years that in 2008 comes to a normal but still high level. To attract high potentialworkers and engineers to support further growth, the region has one main advantage to many other regions – its environment. In caseof “Lake of Constance” region, different marketing strategies were used. The complexity of successful marketing for a region is highand finding the right combination of marketing strategies is difficult but can positively influence the development of a region, itseconomy and tourism. At the same time, the marketing for economy and tourism positively reflects degree of popularity in the region.

Geophysical study of the Clear Lake region, California

Energy Technology Data Exchange (ETDEWEB)

Chapman, R.H.

1975-01-01

Results of geophysical studies in the Clear Lake region of California, north of San Francisco, have revealed a prominent, nearly circular negative gravity anomaly with an amplitude of more than 25 milligals (mgal) and an areal extent of approximately 250 square miles and, in addition, a number of smaller positive and negative anomalies. The major negative gravity anomaly is closely associated with the Clear Lake volcanic field and with an area characterized by hot springs and geothermal fields. However, the anomaly cannot be explained by mapped surface geologic features of the area. Aeromagnetic data in the Clear Lake region show no apparent correlation with the major negative gravity anomaly; the local magnetic field is affected principally by serpentine. An electrical resistivity low marks the central part of the gravity minimum, and a concentration of earthquake epicenters characterizes the Clear Lake volcanic field area. The primary cause of the major negative gravity anomaly is believed to be a hot intrusive mass, possibly a magma chamber, that may underlie the Clear Lake volcanic field and vicinity. This mass may serve as a source of heat for the geothermal phenomena in the area. Other smaller gravity anomalies in the Clear Lake region are apparently caused by near-surface geologic features, including relatively dense units of the Franciscan Formation and less dense Cenozoic sedimentary and volcanic rock units.

Prediction of lake depth across a 17-state region in the United States

Science.gov (United States)

Oliver, Samantha K.; Soranno, Patricia A.; Fergus, C. Emi; Wagner, Tyler; Winslow, Luke A.; Scott, Caren E.; Webster, Katherine E.; Downing, John A.; Stanley, Emily H.

2016-01-01

Lake depth is an important characteristic for understanding many lake processes, yet it is unknown for the vast majority of lakes globally. Our objective was to develop a model that predicts lake depth using map-derived metrics of lake and terrestrial geomorphic features. Building on previous models that use local topography to predict lake depth, we hypothesized that regional differences in topography, lake shape, or sedimentation processes could lead to region-specific relationships between lake depth and the mapped features. We therefore used a mixed modeling approach that included region-specific model parameters. We built models using lake and map data from LAGOS, which includes 8164 lakes with maximum depth (Zmax) observations. The model was used to predict depth for all lakes ≥4 ha (n = 42 443) in the study extent. Lake surface area and maximum slope in a 100 m buffer were the best predictors of Zmax. Interactions between surface area and topography occurred at both the local and regional scale; surface area had a larger effect in steep terrain, so large lakes embedded in steep terrain were much deeper than those in flat terrain. Despite a large sample size and inclusion of regional variability, model performance (R2 = 0.29, RMSE = 7.1 m) was similar to other published models. The relative error varied by region, however, highlighting the importance of taking a regional approach to lake depth modeling. Additionally, we provide the largest known collection of observed and predicted lake depth values in the United States.

Glacialmorphological reconstruction of glacier advances and glacial lake outburst floods at the Cachapoal glacier in the Dry Central Andes of Chile (34°S)

Science.gov (United States)

Iturrizaga, Lasafam; Charrier, Reynaldo

2013-04-01

Throughout the Andes Mountain range of South America a general trend of glacier shrinkage has taken place in the last century. Only a few glaciers have shown a rather non-continuous trend of glacier retreat and temporally advanced or even surged during the mid-19th to 20th century. One of the earliest assumed glacier surges has occurred in the upper Cachapoal catchment area at the homonymous glacier. In climatic respect the Cachapoal glacier is located in the transition zone from the most southern part of the Dry Central Andes of Chile to the more humid zone of the Wet Andes. The region is affected mainly by winter precipitation deriving from the Westerlies. The debris-covered, 12 km-long Cachapoal glacier represents one of the largest valley glaciers in the Central Andes. It is an avalanche-fed glacier with an almost 1500 m-high head wall in its upper catchment area flowing down from Picos del Barroso (5180 m) and terminates at an elevation of 2630 m a.s.l. with a bifurcated glacier tongue. A large moraine complex, almost 2 km in length and 500 m in width, separates the two glacier lobes. During times of advanced glacier tongue positions the Ríos Molina and Cachapoal may be have blocked independently at two distinct localities which are situated about 2300 m apart from each other. A blockage with temporal lake formation has occurred at least in the years 1848, 1955 and 1981 (cf. Plagemann 1887, Peña 1981), from which the rupture of the earliest glacier barrier has been the most devastating. This event is locally reminded as "la gran avenida en seco" in the historical record. Geomorphological evidence of the past historical and modern glacier expansions is given in the proglacial area by a fresh dead-ice hummocky topography and glacial trimlines at the valley flanks. More down valley broad outwash plains and boulder clusters indicate past high energy floods produced by glacier lake outbursts. Regarding the small size of the catchment area of the Río Molina

The 2010–2015 megadrought in central Chile: impacts on regional hydroclimate and vegetation

Directory of Open Access Journals (Sweden)

R. D. Garreaud

2017-12-01

Full Text Available Since 2010 an uninterrupted sequence of dry years, with annual rainfall deficits ranging from 25 to 45 %, has prevailed in central Chile (western South America, 30–38° S. Although intense 1- or 2-year droughts are recurrent in this Mediterranean-like region, the ongoing event stands out because of its longevity and large extent. The extraordinary character of the so-called central Chile megadrought (MD was established against century long historical records and a millennial tree-ring reconstruction of regional precipitation. The largest MD-averaged rainfall relative anomalies occurred in the northern, semi-arid sector of central Chile, but the event was unprecedented to the south of 35° S. ENSO-neutral conditions have prevailed since 2011 (except for the strong El Niño in 2015, contrasting with La Niña conditions that often accompanied past droughts. The precipitation deficit diminished the Andean snowpack and resulted in amplified declines (up to 90 % of river flow, reservoir volumes and groundwater levels along central Chile and westernmost Argentina. In some semi-arid basins we found a decrease in the runoff-to-rainfall coefficient. A substantial decrease in vegetation productivity occurred in the shrubland-dominated, northern sector, but a mix of greening and browning patches occurred farther south, where irrigated croplands and exotic forest plantations dominate. The ongoing warming in central Chile, making the MD one of the warmest 6-year periods on record, may have also contributed to such complex vegetation changes by increasing potential evapotranspiration. We also report some of the measures taken by the central government to relieve the MD effects and the public perception of this event. The understanding of the nature and biophysical impacts of the MD helps as a foundation for preparedness efforts to confront a dry, warm future regional climate scenario.

Mercury contamination in the Laurentian Great Lakes region: Introduction and overview

International Nuclear Information System (INIS)

Wiener, James G.; Evers, David C.; Gay, David A.; Morrison, Heather A.; Williams, Kathryn A.

2012-01-01

The Laurentian Great Lakes region of North America contains substantial aquatic resources and mercury-contaminated landscapes, fish, and wildlife. This special issue emanated from a bi-national synthesis of data from monitoring programs and case studies of mercury in the region, here defined as including the Great Lakes, the eight U.S. states bordering the Great Lakes, the province of Ontario, and Lake Champlain. We provide a retrospective overview of the regional mercury problem and summarize new findings from the synthesis papers and case studies that follow. Papers in this issue examine the chronology of mercury accumulation in lakes, the importance of wet and dry atmospheric deposition and evasion to regional mercury budgets, the influence of land–water linkages on mercury contamination of surface waters, the bioaccumulation of methylmercury in aquatic foods webs; and ecological and health risks associated with methylmercury in a regionally important prey fish. - Highlights: ► We describe a bi-national synthesis of Hg data from the Great Lakes region. ► Emission controls have reduced Hg inputs to inland lakes about 20% since the 1980s. ► Wet and dry deposition and evasion are regionally important atmospheric Hg fluxes. ► Land use affects Hg inputs to surface waters and bioaccumulation of methylmercury. ► In some waters, Hg levels in yellow perch pose risks to fish, wildlife, and humans. - A synthesis of Hg data from the Great Lakes region reveals the chronology of contamination; the importance of wet and dry deposition and evasion to Hg budgets; the influence of land–water linkages; bioaccumulation in aquatic foods webs; and risks associated with Hg in an important prey fish.

Regional versus local influences on lead and cadmium loading to the Great Lakes region

Energy Technology Data Exchange (ETDEWEB)

Yohn, S.; Long, D.; Fett, J.; Patino, L. [Michigan State University, East Lansing, MI (United States). Dept. of Geological Science

2004-07-01

Environmental legislation has reduced the anthropogenic loadings of Pb and Cd to the Great Lakes region over the past 3 decades. However, the accumulation rates of these metals still remain above background values. Because environmental legislation was targeted at major sources (e.g., Pb in gasoline) whose influence on the environment was on a regional scale, local sources (e.g., watershed scale) for the metals may now play a more significant role. The relative importance of regional versus local scale influences on metal inputs to the environment is poorly understood. In this study, sediment chronologies of Pb and Cd were examined from 12 inland lakes that cover the broad geographic area of the State of Michigan. These chronologies were compared temporally and spatially and to watershed population densities and metal production records to gain an understanding of local and regional influences on metal inputs to the Great Lakes region. Results show that anthropogenic Pb loading during the 1930s and 1970s was dominated by regional sources. such as coal burning and use of leaded gasoline. Current loadings are now more related to local influences such as watershed population densities, rather than atmospheric deposition. Anthropogenic Cd loadings to the Great Lakes region have been dominated by both regional and local sources over time. Lead may also have shown the influence of local sources over time, if the influence of emissions from gasoline had not been present. This work shows that Pb and Cd loadings in the Great Lakes region are strongly related to watershed population densities; however, the specific sources and pathways for the metal cycling are unclear.

Hantavirus en roedores de la Octava Región de Chile Hantavirus in rodents of the VIII Region of Chile

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JUAN CARLOS ORTIZ

2004-06-01

Full Text Available La Octava Región de Chile corresponde a la segunda región con el mayor número de casos de Síndrome Cardiopulmonar por Hantavirus (SCPH. Por tal motivo se realizó un estudio para detectar la presencia de anticuerpos contra hantavirus en roedores y su distribución local en la Octava Región. El estudio comprendió las cuatro provincias de la región y consideró once sitios de muestreo. Se capturaron siete especies de roedores, Abrothrix olivaceus fue la más abundante seguida de Oligoryzomys longicaudatus. De los 300 roedores analizados, cinco ejemplares (1,66 % resultaron ser positivos a hantavirus y correspondieron a tres especies de sigmodontinos: a saber, Loxodontomys micropus, que corresponde al único registro de este tipo para la especie en Chile, Abrotrix longipilis y Oligoryzomys longicaudatusThe Eight Region has the second highest number of cases of Hantavirus Cardiopulmonary Syndrome (HCPS in humans for Chile. A study was performed to identify the number of rodents serologically positive to hantavirus and their local distribution in this region. To achieve this goal, we sampled eleven sites in the four provinces of the region. Seven rodents species were collected, with Abrothrix olivaceus presenting the largest number of captures followed by Oligoryzomys longicaudatus. Of the 300 rodents analyzed, five (1.66 % were sero-positives to hantavirus and belonged to three different sigmodontine species: Abrothrix longipilis, O. longicaudatus, and Loxodontomys micropus. No previous records of seropositive L. micropus existed.

Regionalization of precipitation characteristics in Iran's Lake Urmia basin

Science.gov (United States)

Fazel, Nasim; Berndtsson, Ronny; Uvo, Cintia Bertacchi; Madani, Kaveh; Kløve, Bjørn

2018-04-01

Lake Urmia in northwest Iran, once one of the largest hypersaline lakes in the world, has shrunk by almost 90% in area and 80% in volume during the last four decades. To improve the understanding of regional differences in water availability throughout the region and to refine the existing information on precipitation variability, this study investigated the spatial pattern of precipitation for the Lake Urmia basin. Daily rainfall time series from 122 precipitation stations with different record lengths were used to extract 15 statistical descriptors comprising 25th percentile, 75th percentile, and coefficient of variation for annual and seasonal total precipitation. Principal component analysis in association with cluster analysis identified three main homogeneous precipitation groups in the lake basin. The first sub-region (group 1) includes stations located in the center and southeast; the second sub-region (group 2) covers mostly northern and northeastern part of the basin, and the third sub-region (group 3) covers the western and southern edges of the basin. Results of principal component (PC) and clustering analyses showed that seasonal precipitation variation is the most important feature controlling the spatial pattern of precipitation in the lake basin. The 25th and 75th percentiles of winter and autumn are the most important variables controlling the spatial pattern of the first rotated principal component explaining about 32% of the total variance. Summer and spring precipitation variations are the most important variables in the second and third rotated principal components, respectively. Seasonal variation in precipitation amount and seasonality are explained by topography and influenced by the lake and westerly winds that are related to the strength of the North Atlantic Oscillation. Despite using incomplete time series with different lengths, the identified sub-regions are physically meaningful.

40 CFR 81.67 - Lake Michigan Intrastate Air Quality Control Region.

Science.gov (United States)

2010-07-01

... Quality Control Regions § 81.67 Lake Michigan Intrastate Air Quality Control Region. The Menominee-Escanaba (Michigan)-Marinette (Wisconsin) Interstate Air Quality Control Region has been renamed the Lake Michigan Intrastate Air Quality Control Region (Wisconsin) and revised to consist of the territorial area...

Identifying Watershed Regions Sensitive to Soil Erosion and Contributing to Lake Eutrophication—A Case Study in the Taihu Lake Basin (China)

Science.gov (United States)

Lin, Chen; Ma, Ronghua; He, Bin

2015-01-01

Taihu Lake in China is suffering from severe eutrophication partly due to non-point pollution from the watershed. There is an increasing need to identify the regions within the watershed that most contribute to lake water degradation. The selection of appropriate temporal scales and lake indicators is important to identify sensitive watershed regions. This study selected three eutrophic lake areas, including Meiliang Bay (ML), Zhushan Bay (ZS), and the Western Coastal region (WC), as well as multiple buffer zones next to the lake boundary as the study sites. Soil erosion intensity was designated as a watershed indicator, and the lake algae area was designated as a lake quality indicator. The sensitive watershed region was identified based on the relationship between these two indicators among different lake divisions for a temporal sequence from 2000 to 2012. The results show that the relationship between soil erosion modulus and lake quality varied among different lake areas. Soil erosion from the two bay areas was more closely correlated with water quality than soil erosion from the WC region. This was most apparent at distances of 5 km to 10 km from the lake, where the r2 was as high as 0.764. Results indicate that soil erosion could be used as an indicator for identifying key watershed protection areas. Different lake areas need to be considered separately due to differences in geographical features, land use, and the corresponding effects on lake water quality. PMID:26712772

Identifying Watershed Regions Sensitive to Soil Erosion and Contributing to Lake Eutrophication--A Case Study in the Taihu Lake Basin (China).

Science.gov (United States)

Lin, Chen; Ma, Ronghua; He, Bin

2015-12-24

Taihu Lake in China is suffering from severe eutrophication partly due to non-point pollution from the watershed. There is an increasing need to identify the regions within the watershed that most contribute to lake water degradation. The selection of appropriate temporal scales and lake indicators is important to identify sensitive watershed regions. This study selected three eutrophic lake areas, including Meiliang Bay (ML), Zhushan Bay (ZS), and the Western Coastal region (WC), as well as multiple buffer zones next to the lake boundary as the study sites. Soil erosion intensity was designated as a watershed indicator, and the lake algae area was designated as a lake quality indicator. The sensitive watershed region was identified based on the relationship between these two indicators among different lake divisions for a temporal sequence from 2000 to 2012. The results show that the relationship between soil erosion modulus and lake quality varied among different lake areas. Soil erosion from the two bay areas was more closely correlated with water quality than soil erosion from the WC region. This was most apparent at distances of 5 km to 10 km from the lake, where the r² was as high as 0.764. Results indicate that soil erosion could be used as an indicator for identifying key watershed protection areas. Different lake areas need to be considered separately due to differences in geographical features, land use, and the corresponding effects on lake water quality.

Regional variability among nonlinear chlorophyll-phosphorus relationships in lakes

Science.gov (United States)

Filstrup, Christopher T.; Wagner, Tyler; Soranno, Patricia A.; Stanley, Emily H.; Stow, Craig A.; Webster, Katherine E.; Downing, John A.

2014-01-01

The relationship between chlorophyll a (Chl a) and total phosphorus (TP) is a fundamental relationship in lakes that reflects multiple aspects of ecosystem function and is also used in the regulation and management of inland waters. The exact form of this relationship has substantial implications on its meaning and its use. We assembled a spatially extensive data set to examine whether nonlinear models are a better fit for Chl a—TP relationships than traditional log-linear models, whether there were regional differences in the form of the relationships, and, if so, which regional factors were related to these differences. We analyzed a data set from 2105 temperate lakes across 35 ecoregions by fitting and comparing two different nonlinear models and one log-linear model. The two nonlinear models fit the data better than the log-linear model. In addition, the parameters for the best-fitting model varied among regions: the maximum and lower Chl aasymptotes were positively and negatively related to percent regional pasture land use, respectively, and the rate at which chlorophyll increased with TP was negatively related to percent regional wetland cover. Lakes in regions with more pasture fields had higher maximum chlorophyll concentrations at high TP concentrations but lower minimum chlorophyll concentrations at low TP concentrations. Lakes in regions with less wetland cover showed a steeper Chl a—TP relationship than wetland-rich regions. Interpretation of Chl a—TP relationships depends on regional differences, and theory and management based on a monolithic relationship may be inaccurate.

The influence of carbon exchange of a large lake on regional tracer-transport inversions: results from Lake Superior

International Nuclear Information System (INIS)

Vasys, Victoria N; Desai, Ankur R; McKinley, Galen A; Bennington, Val; Michalak, Anna M; Andrews, Arlyn E

2011-01-01

Large lakes may constitute a significant component of regional surface-atmosphere fluxes, but few efforts have been made to quantify these fluxes. Tracer-transport inverse models that infer the CO 2 flux from the atmospheric concentration typically assume that the influence from large lakes is negligible. CO 2 observations from a tall tower in Wisconsin segregated by wind direction suggested a CO 2 signature from Lake Superior. To further investigate this difference, source-receptor influence functions derived using a mesoscale transport model were applied and results revealed that air masses sampled by the tower have a transit time over the lake, primarily in winter when the total lake influence on the tower can exceed 20% of the total influence of the regional domain. When the influence functions were convolved with air-lake fluxes estimated from a physical-biogeochemical lake model, the overall total contribution of lake fluxes to the tall tower CO 2 were mostly negligible, but potentially detectable in certain periods of fall and winter when lake carbon exchange can be strong and land carbon efflux weak. These findings suggest that large oligotrophic lakes would not significantly influence inverse models that incorporate tall tower CO 2 .

Effects of lake trout refuges on lake whitefish and cisco in the Apostle Islands Region of Lake Superior

Science.gov (United States)

Zuccarino-Crowe , Chiara M.; Taylor, William W.; Hansen, Michael J.; Seider, Michael J.; Krueger, Charles C.

2016-01-01

Lake trout refuges in the Apostle Islands region of Lake Superior are analogous to the concept of marine protected areas. These refuges, established specifically for lake trout (Salvelinus namaycush) and closed to most forms of recreational and commercial fishing, were implicated as one of several management actions leading to successful rehabilitation of Lake Superior lake trout. To investigate the potential significance of Gull Island Shoal and Devils Island Shoal refuges for populations of not only lake trout but also other fish species, relative abundances of lake trout, lake whitefish (Coregonus clupeaformis), and cisco (Coregonus artedi) were compared between areas sampled inside versus outside of refuge boundaries. During 1982–2010, lake trout relative abundance was higher and increased faster inside the refuges, where lake trout fishing was prohibited, than outside the refuges. Over the same period, lake whitefish relative abundance increased faster inside than outside the refuges. Both evaluations provided clear evidence that refuges protected these species. In contrast, trends in relative abundance of cisco, a prey item of lake trout, did not differ significantly between areas inside and outside the refuges. This result did not suggest indirect or cascading refuge effects due to changes in predator levels. Overall, this study highlights the potential of species-specific refuges to benefit other fish species beyond those that were the refuges' original target. Improved understanding of refuge effects on multiple species of Great Lakes fishes can be valuable for developing rationales for refuge establishment and predicting associated fish community-level effects.

Acordos bilaterais de comércio como estratégia de inserção regional e internacional do Chile Bilateral trade agreements as Chile's strategy for regional and international insertion

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Renata Rossetto Lopes

2010-12-01

Full Text Available O trabalho analisa a mudança na estratégia de inserção regional e internacional do Chile no começo dos anos 1990, com ênfase em acordos comerciais bilaterais, depois de ter praticado a abertura comercial generalizada desde meados da década de 1970. A opção por acordos bilaterais foi adotada pelo primeiro governo democrático, como parte da orientação de manter e aprofundar a abertura externa empreendida pela ditadura, e conseguiu ampliar as vendas externas e diversificar produtos e destinos. As exportações têm papel decisivo na economia chilena, aberta e pequena, e os 24 acordos bilaterais de comércio com diferentes países e regiões, além de outros em negociação, podem ser explicados pelo esgotamento das possibilidades de ampliar o comércio por meio de reduções adicionais da tarifa externa unilateral, hoje em 6% para quase todos os produtos. A formação de uma rede de acordos bilaterais ampla e diversificada, contudo, tem também interesses políticos, estratégicos e de segurança em relação a vizinhos e a países próximos, além de evitar que o Chile precise se integrar, como membro pleno, a blocos regionais para garantir seus interesses, o que amplia as possibilidades de lidar com diferentes e importantes parceiros no âmbito internacional.The paper analysis the change of Chile's regional and international strategy of insertion through bilateral trade agreements in the beginning of the 90s, after a generalized trade opening since the middle of the 70s. The bilateral trade agreements strategy was set up by the democratic governments as part of the direction of maintaining and deepening the unilateral trade liberalization undertaken by the dictatorship, enlarging exports and diversifying products and markets. Exports have a decisive role in Chile's economy, open and small. The 24 bilateral trade agreements already signed with different countries and regions (besides others under negotiation can be explained by the

Quaternary lacustrine braid deltas on Lake General Carrera in southern Chile Deltas entrelazados lacustres del Cuaternario en el lago General Carrera, sur de Chile

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C. Mike Bell

2009-01-01

Full Text Available A series of Quaternary lacustrine braid deltas on the shores of Lake General Carrera in southern Chile formed as a result of falls in lake level. Each delta comprises two components, the delta fan and the beach embayment, each in turn comprising an onshore subaerial and an offshore subaqueous element. The delta fans have a classic Gilbert form with a braided delta top and a steeply inclined delta front. Adjacent to the fans are concave beach embayments that formed parallel with the deltas as they prograded into the lake. The delta sediments consist predominantly of matrix- and clast-supported gravéis to a total composite thickness exceeding 400 m. The depositional environments are dominated by ephemeral river flooding and by storm-driven waves. Beach sediment is sorted, rounded, winnowed and transported alongshore by waves to fill the beach embayment with ridges of very well sorted and well-rounded gravel. A gently-dipping shoreface platform occurs up to 100 m offshore between the beach and the brink point. From the brink point, in water depth of about 8 m, sediment cascades down the steep delta front slope to form long foresets extending to the lake floor. The sedimentary successions therefore wedge in the opposite direction from those of tectonically controlled basin margins where fan growth keeps pace with basin subsidence.Una serie de deltas entrelazados lacustres, pertenecientes al Cuaternario, ubicados en las costas del lago General Carrera, en el sur de Chile, se formaron como resultado de caídas en el nivel del lago. Cada delta consta de dos componentes: el abanico deltaico y la zona de embahiamiento. Cada uno de ellos tiene, a su vez, un elemento subaéreo costero y un elemento subacuático. Los abanicos deltaicos tienen una forma Gilbert clásica con una parte superior de ríos entrelazados y un frente deltaico empinado. Adyacente a los abanicos aluviales existen bahías cóncavas de playa que se formaron de manera paralela a los

Decadal oscillation of lakes and aquifers in the upper Great Lakes region of North America: hydroclimatic implications

Science.gov (United States)

Watras, C.J.; Read, J.S.; Holman, K.D.; Liu, Z.; Song, Y.-Y.; Watras, A.J.; Morgan, S.; Stanley, E.H.

2014-01-01

We report a unique hydrologic time-series which indicates that water levels in lakes and aquifers across the upper Great Lakes region of North America have been dominated by a climatically-driven, near-decadal oscillation for at least 70 years. The historical oscillation (~13y) is remarkably consistent among small seepage lakes, groundwater tables and the two largest Laurentian Great Lakes despite substantial differences in hydrology. Hydrologic analyses indicate that the oscillation has been governed primarily by changes in the net atmospheric flux of water (P-E) and stage-dependent outflow. The oscillation is hypothetically connected to large-scale atmospheric circulation patterns originating in the mid-latitude North Pacific that support the flux of moisture into the region from the Gulf of Mexico. Recent data indicate an apparent change in the historical oscillation characterized by a ~12y downward trend beginning in 1998. Record low water levels region-wide may mark the onset of a new hydroclimatic regime.

Lake Urmia (Iran): can future socio-ecologically motivated river basin management restore lake water levels in an arid region with extensive agricultural development?

Science.gov (United States)

Fazel, Nasim; Berndtsson, Ronny; Bertacchi Uvo, Cintia; Klove, Bjorn; Madani, Kaveh

2015-04-01

Lake Urmia, one of the world's largest hyper saline lakes located in northwest of Iran, is a UNESCO Biosphere Reserve and Ramsar site, protected as a national park and, supports invaluable and unique biodiversity and related ecosystem services for the region's 6.5 million inhabitants. Due to increased development of the region's water resources for agriculture and industry and to a certain extent climate change, the lake has started to shrink dramatically since 1995 and now is holding less than 30 percent of its volume. Rapid development in agricultural sector and land-use changes has resulted in immense construction of dams and water diversions in almost all lake feeding rivers, intensifying lake shrinking, increasing salinity and degrading its ecosystem. Recently, lake's cultural and environmental importance and social pressure has raised concerns and brought government attention to the lake restoration plans. Along with poor management, low yield agriculture as the most water consuming activity in the region with, rapid, insufficient development is one of the most influential drivers in the lake desiccation. Part of the lake restoration plans in agricultural sector is to restrict the agricultural areas in the main feeding river basins flowing mostly in the southern part of the lake and decreasing the agricultural water use in this area. This study assess the efficiency and effectiveness of the proposed plans and its influence on the lake level rise and its impacts on economy in the region using a system dynamics model developed for the Lake consist of hydrological and agro-economical sub-systems. The effect of decrease in agricultural area in the region on GDP and region economy was evaluated and compared with released water contribution in lake level rise for a five year simulation period.

The emerging architecture of a regional security complex in the Lake ...

African Journals Online (AJOL)

This article explores the emerging regional security architecture to fight terrorism and insurgency in the Lake Chad Basin (LCB). It diagnoses the evolution of the Lake Chad Basin Commission (LCBC) as a sub-regional organization that unites Chad, Cameroon, Niger and Nigeria. In particular, the article critically investigates ...

Quality of drinking water from ponds in villages of Kolleru Lake region.

Science.gov (United States)

Rao, A S; Rao, P R; Rao, N S

2001-01-01

Kolleru Lake is the largest natural freshwater lake in the districts of East and West Godavari of Andhra Pradesh. The major population centres in the Kolleru Lake region are the 148 villages of which 50 bed villages and 98 belt villages. All bed and belt villages in lake region have at least one drinking water pond. Drinking water ponds are filled with lake water during monsoon season and directly supplied to the public throughout the year. The water samples were collected from village drinking water ponds in a year by covering three seasons and analysed for different physico-chemical parameters to assess the quality of drinking water.

Climate Change Assessments for Lakes Region of Turkey

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Ayten Erol

2012-07-01

Full Text Available Climate change is one of the most important challenges for forestry. Forests are known to be most efficient natural tools to ensure availability and quality of water in many regions. Besides, planning of forest resources towards water quality and quantity is essential in countries that are expected to face with more frequent drought periods in the next decades due to climate change. Watershed management concept has been supposed as the primary tool to plan natural resources in a more efficient and sustainable way by both academicians and practitioners to mitigate and adapt climate change. Forest cover among other land use types provides the best regulating mechanism to mitigate erosion, sedimentation, desertification, and pollution. In addition, climate change can potentially affect forest stand dynamics by influencing the availability of water resources. Therefore, the amount of forest cover in a watershed is an indicator of climate change mitigation and adaptation. Climate change is a concern and risk for the sustainability of water resources in Lakes Region of Turkey. The objective of this study is to make a comprehensive assessment in lake watersheds of the Lakes region considering the forest cover. For this purpose, the study gives a general view of trends in climatic parameters using Mann Kendall trend test. The results showed that Mann Kendall trend test for temperature and precipitation data is not enough to evaluate the magnitude of potential changes of climate in terms of forest cover. Understanding impacts of changes in temperature and precipitation on forest cover, runoff data should be evaluated with temperature and precipitation for watersheds of forest areas in Lakes Region.

Registro nuevo de Amphipyrinae en Chile A new record of Amphipyrinae from Chile

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Tania S. Olivares

2006-12-01

Full Text Available Se registra por primera vez en Chile la especie Agrotisia subhyalina Hampson, entre las latitudes 18° 29' S 70° 20' O hasta 29° 54' S 71° 16' O (I-IV regiones en Chile. Se redescriben los genitales del macho y de la hembra y se presentan algunos aspectos taxonómicos de la especie.The species Agrotisia subhyalina Hampson is recorded for the first time from Chile (18° 29' S 70° 20' W to 29° 54' S 71° 16' W, I to IV Chilean regions. Redescriptions of male and female are presented, along with some taxonomic aspects of the species.

Ecosystem evolution of Lake Gusinoe (Transbaikal region, Russia)

Energy Technology Data Exchange (ETDEWEB)

Pisarsky, B.L.; Hardina, A.M.; Naganawa, H. [Russian Academy of Science, Irkutsk (Russian Federation). Siberian Division

2005-12-01

Lake Gusinoe is situated on a basin originating from Paleozoic and Mesozoic deposits. The recorded history of the lake's ecosystem evolution is no more than 300 years. The present lake drainage basin was formed mainly in the Cenozoic era, but during the past century, major anthropogenic impacts on the lake have occurred. The human-influenced evolution of the ecosystem began in the 1940s with the development of opencut coal mining nearby the lake. Population increase and the building of the Gusinoozersk State Regional Power Plant, the TransMongolian Railroad and an associated station, and military installations were the major sources of anthropogenic impacts. Since the early 1950s about five species of fish have been introduced into Lake Gusinoe or have invaded the lake, and at least six of the native species have disappeared or are in danger of extinction. From our recent investigations, the present environment of the Lake Gusinoe Basin (Gusinoozersk Basin) is divided into four zones hydro-geochemically: (1) ultrafreshwater, (2) freshwater, (3) mineralized water, and (4) hyposaline and saltwater. Some additional data on changes of the chemical components of the drainage basin waters, as well as on the transition of zooplankton and zoobenthic fauna, are presented in consideration of the risk of industrial development, and the perspectives are discussed.

Analysis of the dynamic of underground water in Agua Verde, Quebrada de Taltal, region of Antofagasta, Chile

International Nuclear Information System (INIS)

Rojas, Luis; Lillo, Adrian; Salazar, Carlos; Aguirre, Evelyn

2003-01-01

The extreme aridity and geological situation in northern. Chile requires an exhaustive investigation on water resources for supporting rational usage. The Direccion General de Aguas and Comision Chilena de Energia Nuclear have performed studies in arid zones in northern Chile using isotopic and hydrochemical tools. In Quebrada de Taltal's basin, located in one of the must arid arid zones of Chile (Segunda Region de Antofagasta), was studies groundwater dynamics and recharge process from a geochemical approach in terms of water quality, temperature and isotopic composition ( 2 H, 18 O, 3 H, 14 C). The recharge generated above 3000 m a.s.t has a slow dynamics and involve little flow (author)

Topoclimatic modeling for minimum temperature prediction at a regional scale in the Central Valley of Chile

International Nuclear Information System (INIS)

Santibáñez, F.; Morales, L.; Fuente, J. de la; Cellier, P.; Huete, A.

1997-01-01

Spring frost may strongly affect fruit production in the Central Valley of Chile. Minimum temperatures are spatially variable owing to topography and soil conditions. A methodology for forecasting minimum temperature at a regional scale in the Central Valley of Chile, integrating spatial variability of temperature under radiative frost conditions, has been developed. It uses simultaneously a model for forecasting minimum temperatures at a reference station using air temperature and humidity measured at 6 pm, and topoclimatic models, based on satellite infra-red imagery (NOAA/AVHRR) and a digital elevation model, to extend the prediction at a regional scale. The methodological developments were integrated in a geographic information system for geo referencing of a meteorological station with satellite imagery and modeled output. This approach proved to be a useful tool for short range (12 h) minimum temperature prediction by generating thermal images over the Central Valley of Chile. It may also be used as a tool for frost risk assessment, in order to adapt production to local climatological conditions. (author)

Wildlife in the Upper Great Lakes Region: a community profile.

Science.gov (United States)

Janine M. Benyus; Richard R. Buech; Mark D. Nelson

1992-01-01

Wildlife habitat data from seven Great Lakes National Forests were combined into a wildlife-habitat matrix named NORTHWOODS. The composite NORTHWOODS data base is summarized. Multiple queries of NORTHWOODS were used to profile the wildlife community of the Upper Great Lakes region.

Simulation of Lake Surface Heat Fluxes by the Canadian Small Lake Model: Offline Performance Assessment for Future Coupling with a Regional Climate Model

Science.gov (United States)

Pernica, P.; Guerrero, J. L.; MacKay, M.; Wheater, H. S.

2014-12-01

Lakes strongly influence local and regional climate especially in regions where they are abundant. Development of a lake model for the purpose of integration within a regional climate model is therefore a subject of scientific interest. Of particular importance are the heat flux predictions provided by the lake model since they function as key forcings in a fully coupled atmosphere-land-lake system. The first step towards a coupled model is to validate and characterize the accuracy of the lake model over a range of conditions and to identify limitations. In this work, validation results from offline tests of the Canadian Small Lake Model; a deterministic, computationally efficient, 1D integral model, are presented. Heat fluxes (sensible and latent) and surface water temperatures simulated by the model are compared with in situ observations from two lakes; Landing Lake (NWT, Canada) and L239 (ELA, Canada) for the 2007-2009 period. Sensitivity analysis is performed to identify key parameters important for heat flux predictions. The results demonstrate the ability of the 1-D lake model to reproduce both diurnal and seasonal variations in heat fluxes and surface temperatures for the open water period. These results, in context of regional climate modelling are also discussed.

El Chile de las regiones: una historia inconclusa

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Arenas, Federico

2009-06-01

Full Text Available The Chilean regions have a history that dates back several decades since the first attempts to establish regionalization in the fifties, until the Regional Governments were installed in 1993. Nevertheless, the critical reading of the regionalization process and decentralization show that beyond many advances, we are still far from representing a country with a unitary decentralized state model. In this work, the most important milestones of the Chilean institutional development are revised at a regional scale, in order to establish the level of advance and the overdue challenges on this subject in the country.

Las regiones chilenas tienen una historia que se remonta a varias décadas, desde los primeros intentos de establecer una regionalización en Chile en los años cincuenta, hasta la instalación de los denominados Gobiernos Regionales el año 1993. Sin embargo, la lectura crítica del proceso de regionalización y sobre todo de la descentralización, muestra que más allá de los innumerables avances, todavía estamos lejos de representar como país, un modelo de estado unitario desconcentrado. En este trabajo se revisan los hitos más importantes del desarrollo institucional chileno a la escala regional, con el fin de establecer el nivel de avance y los desafíos pendientes del país en esta materia.

Critical pathways of change in fruit export regions at desert margin (Chile)

DEFF Research Database (Denmark)

Frederiksen, Peter

The purpose is to elucidate how critical pathways function in a fruit export region at the desert margin in Chile. The region was investigated at the system level as an open land system with managed fruit plantations in a geographically complex valley. Data collection procedures included total...... change changed pathways. Pathways resulted from a combination of global value chains, the adoption of innovations, past climate change, and regional conditions at different scales. Main pathways of change were upgrade and downgrade of the fruit export region and irrigation systems, whereas the breaking...... areas and not in others. The probable future is expected to be increased separation of intraregional pathways and a more imbalanced region. The conclusion is that openness is the main property responsible for critical pathways of change in the region....

Propensity of University Students in the Region of Antofagasta, Chile to Create Enterprise

Science.gov (United States)

Romani, Gianni; Didonet, Simone; Contuliano, Sue-Hellen; Portilla, Rodrigo

2013-01-01

The authors aim to discuss the propensity or intention to create enterprise among university students in the region of Antofagasta, Chile, and to analyze the factors that influence the step from desire to intention. 681 students were surveyed. The data were analyzed by binary logistical regression. The results show that curriculum is among the…

The shallow-water chitons (Mollusca, Polyplacophora of Caldera, Region of Atacama, northern Chile

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Juan Francisco Araya

2015-03-01

Full Text Available The Molluscan species of the northern littoral of Chile have been sparsely studied. This work reviews for the first time the diversity of polyplacophoran molluscs around the port of Caldera, in the Region of Atacama (26°45’49”S; 70°45’17”W to 27°20’23”S; 70°56’46”W, northern Chile. Eleven species were found in this study: Acanthopleura echinata (Barnes, 1824; Callistochiton pulchellus (Gray, 1828; Calloplax vivipara (Plate, 1899, Chaetopleura peruviana (Lamarck, 1819; Chiton cumingsii Frembly, 1827; Chiton granosus Frembly, 1827; Chiton magnificus Deshayes, 1827; Enoplochiton niger (Barnes, 1824, Radsia barnesii (Gray, 1828, Tonicia atrata (G. B. Sowerby II, 1840 and Tonicia chilensis (Frembly, 1827. All of the species occurring in the area have distributions in the southeastern Pacific Ocean, from Ecuador to central Chile, and three of them are species endemic to the Chilean coasts (Calloplax vivipara, Radsia barnesii, and Tonicia atrata. This diversity of species is comparable to that of better surveyed faunas of central and southern Chile or Patagonia. Of the eleven species recorded, the geographic distribution records for Callistochiton pulchellus, Radsia barnesii and Tonicia atrata are extended, and Calloplax vivipara is found alive again after 40 years, filling a gap in its known distribution. Illustrations of living specimens in their habitat, distribution records and a taxonomic key for all the studied taxa are also provided.

Ecological risk of methylmercury to piscivorous fish of the Great Lakes region.

Science.gov (United States)

Sandheinrich, Mark B; Bhavsar, Satyendra P; Bodaly, R A; Drevnick, Paul E; Paul, Eric A

2011-10-01

Contamination of fish populations with methylmercury is common in the region of the Laurentian Great Lakes as a result of atmospheric deposition and methylation of inorganic mercury. Using fish mercury monitoring data from natural resource agencies and information on tissue concentrations injurious to fish, we conducted a screening-level risk assessment of mercury to sexually mature female walleye (Sander vitreus), northern pike (Esox lucius), smallmouth bass (Micropterus dolomieu), and largemouth bass (Micropterus salmoides) in the Great Lakes and in interior lakes, impoundments, and rivers of the Great Lakes region. The assessment included more than 43,000 measurements of mercury in fish from more than 2000 locations. Sexually mature female fish that exceeded threshold-effect tissue concentrations of 0.20 μg g(-1) wet weight in the whole body occurred at 8% (largemouth bass) to 43% (walleye) of sites. Fish at 3% to 18% of sites were at risk of injury and exceeded 0.30 μg g(-1) where an alteration in reproduction or survival is predicted to occur. Most fish at increased risk were from interior lakes and impoundments. In the Great Lakes, no sites had sexually mature fish that exceeded threshold-effect concentrations. Results of this screening-level assessment indicate that fish at a substantive number of locations within the Great Lakes region are potentially at risk from methylmercury contamination and would benefit from reduction in mercury concentrations.

Reaching Regional and Local Learners via a Great Lakes MOOC

Science.gov (United States)

Mooney, M. E.; Ackerman, S. A.

2015-12-01

The Cooperative Institute of Meteorological Satellite Studies (CIMSS) took a regional approach to climate change education in a 4-week MOOC (Massive Open On-line Course) on the Changing Weather and Climate in the Great Lakes Region launched in February 2015. Featuring a different season each week, this Great Lakes MOOC includes lectures about seasonal weather conditions, observed changes, and societal impacts of regional climate change, as well as actions with co-benefits to slow future climate change. To better connect with learners, CIMSS facilitated 21 discussion groups at public libraries around Wisconsin each week. Participants discussed climate change impacts in their communities as well as strategies to mitigate climate change. Not surprisingly, initial survey results show library participants were more committed, engaged, climate literate, and community minded. This session will share lessons learned and survey results from the Great Lakes MOOC which remains open and accessible on Coursera through February 2016 at https://www.coursera.org/course/greatlakesclimate.

Use of high-resolution satellite images for characterization of geothermal reservoirs in the Tarapaca Region, Chile

Science.gov (United States)

Arellano-Baeza, A. A.; Montenegro A., C.

2010-12-01

The use of renewable and clean sources of energy is becoming crucial for sustainable development of all countries, including Chile. Chilean Government plays special attention to the exploration and exploitation of geothermal energy, total electrical power capacity of which could reach 16.000 MW. In Chile the main geothermal fields are located in the Central Andean Volcanic Chain in the North, between the Central valley and the border with Argentina in the center, and in the fault system Liquiñe-Ofqui in the South of the country. High resolution images from the Lansat satellite have been used to characterize the geothermal field in the region of the Puchuldiza geysers, Colchane, Region of Tarapaca, North of Chile, located at the altitude of 4000 m. Structure of lineaments associated to the geothermal field have been extracted from the images using the lineament detection technique developed by authors. These structures have been compared with the distribution of main geological structures obtained in the field. It was found that the lineament analysis is a power tool for the detection of faults and joint zones associated to the geothermal fields.

Challenges in Developing Ecotourism in The Region of Lake Sentani Papua

Directory of Open Access Journals (Sweden)

Yannice Luma Marnala Sitorus

2017-03-01

Full Text Available The concept of community-based ecotourism is one of the sustainable development concepts suitable to be applied to traditional regions with nature tourism potential. Differences in culture between traditional communities and the outside world are not an obstacle in developing the region because with their local wisdom traditional communities can participate in protecting and managing their natural surrounding and at the same time become an attraction for other communities. However, outside societies can influence the culture of the traditional communities that originally tends to be oriented on biocentrism to shift towards anthropocentrism. This can eventually hamper the continuity of ecotourism development. This can be seen from the traditional communities at Lake Sentani, the case study of the author. The study is based on literature and secondary data and used descriptive analysis. The traditional communities of Sentani do not yet fully participate in the development of tourism in its surroundings. Their involvement in tourism development is more focused on ceremonial activities such as can be seen at the Lake Sentani Festival which is organized every year by the government. Besides this, after coming into contact with modern life the traditional communities of Lake Sentani rarely perform their daily activities based on local wisdom aimed at natural conservation of the lake. The development of urban areas in the surroundings also influences changes in land use in the Lake Sentani region which then causes among others erosion, sedimentation, and pollution of the lake water. Socio-economic and cultural changes in the traditional communities of Sentani and the growth of development also contribute towards ecological change in the area of Lake Sentani, the place they live in.

PAH fluxes in the Laja Lake of south central Chile Andes over the last 50 years: Evidence from a dated sediment core

International Nuclear Information System (INIS)

Quiroz, Roberto; Popp, Peter; Urrutia, Roberto; Bauer, Coretta; Araneda, Alberto; Treutler, Hanns-Christian; Barra, Ricardo

2005-01-01

This paper reports the occurrence of polyaromatic hydrocarbons (PAHs) deposition inferred from a sediment core of an Andean lake in south central Chile. Sediments were carefully collected from one of the deepest section of the lake and sliced every 1 cm. The samples were analyzed for PAHs, 137 Cs, 210 Pb, organic carbon and grain-size. The stratigraphic chronology and the sedimentation rates were estimated using the sedimentary signature left by the 137 Cs and 210 Pb fallout as temporal markers. PAHs were quantified by HPLC-fluorescence detection (HPLC-Fluorescence). 15 priority EPA PAHs were analyzed in this study. Based on these results, PAH deposition over the last 50 years was estimated (a period characterized by an important intervention in the area). PAH concentration ranged from 226 to 620 ng g -1 d.w. The highest concentrations of PAHs were found in the core's bottom. The PAH profile is dominated by the presence of perylene indicating a natural source of PAH. In addition, two clear PAH deposition periods could be determined: the most recent with two-four rings PAHs, the older one with five-seven rings predomination. Determined fluxes where 71 to 972 μg m -2 year -1 , dominated by perylene deposition. PAH levels and fluxes are lower compared to the levels found in sediments from remote lakes in Europe and North America. It is concluded that the main source of PAHs into the Laja Lake sediments are of natural origin

The Oligochaeta (Annelida, Clitellata) of the St. Lawrence Great Lakes region: An update

Science.gov (United States)

Spencer, Douglas R.; Hudson, Patrick L.

2003-01-01

An updated oligochaete species list for the Great Lakes region is provided. The list was developed through the reexamination of the taxa reported in a previous report in 1980, addition of new taxa or records collected from the region since 1980, and an update of taxonomy commensurate with systematic and nomenclatural changes over the intervening years since the last review. The authors found 74 papers mentioning Great Lakes oligochaete species. The majority of these papers were published in the 1980s. The literature review and additional collections resulted in 15 species being added to the previous list. Nine taxa were removed from the previous list due to misidentification, synonymies, level of identification, or inability to confirm the identity. Based on this review, 101 species of Oligochaeta are now known from the St. Lawrence Great Lakes watershed. Of these, 95 species are known from the St. Lawrence Great Lakes proper, with an additional 6 species recorded from the inland waters of the watershed. The greatest diversity of oligochaete species was found in the inland waters of the region (81) followed by Lake Huron (72), Lake Ontario (65), Lake Erie (64), Lake Superior (63), Lake Michigan (62), St. Marys River (60), Niagara River (49), Saginaw Bay (44), St. Clair River (37), Lake St. Clair (36), St. Lawrence River (27), and the Detroit River (21). Three species are suspected of being introduced, Branchiura sowerbyi, Gianius aquaedulcisand Ripistes parasita, and two are believed to be endemic, Thalassodrilus hallae andTeneridrilus flexus.

A SIMULATION STUDY ON THE SHRUNK WETLAND AROUND QINGHAI LAKE AND REGIONAL CLIMATE

Institute of Scientific and Technical Information of China (English)

WANG HanJie; JING Li; GAO YunXiao

2005-01-01

Because of the increasing concerns about global climate change, it has been known by more and more peoples that there is a close relationship between wetland and/or peatland resources and climate change. This paper presents a new methodology to study the local climate variation caused by wetland shrinking around Qinghai Lake, the largest in-land salty lake in China, by use of a regional climate model (RCM) that commonly used in climate change study. The objective focuses on the regional climate effect of the shrunk wetland coverage in recent years. The results of numerical experiment showed that if the wetland coverage around Qinhai Lake were recovered as if in early 50s of last century,the regional climate in this area could be better with more cloud covers, higher relative humidity and more precipitation. In the other word, the area of wetland reduced is one of the most important reasons that caused regional climate aridification,eco-environmental deterioration and even desertification around Qinhai Lake.

Effects of land use on lake nutrients: The importance of scale, hydrologic connectivity, and region

Science.gov (United States)

Soranno, Patricia A.; Cheruvelil, Kendra Spence; Wagner, Tyler; Webster, Katherine E.; Bremigan, Mary Tate

2015-01-01

Catchment land uses, particularly agriculture and urban uses, have long been recognized as major drivers of nutrient concentrations in surface waters. However, few simple models have been developed that relate the amount of catchment land use to downstream freshwater nutrients. Nor are existing models applicable to large numbers of freshwaters across broad spatial extents such as regions or continents. This research aims to increase model performance by exploring three factors that affect the relationship between land use and downstream nutrients in freshwater: the spatial extent for measuring land use, hydrologic connectivity, and the regional differences in both the amount of nutrients and effects of land use on them. We quantified the effects of these three factors that relate land use to lake total phosphorus (TP) and total nitrogen (TN) in 346 north temperate lakes in 7 regions in Michigan, USA. We used a linear mixed modeling framework to examine the importance of spatial extent, lake hydrologic class, and region on models with individual lake nutrients as the response variable, and individual land use types as the predictor variables. Our modeling approach was chosen to avoid problems of multi-collinearity among predictor variables and a lack of independence of lakes within regions, both of which are common problems in broad-scale analyses of freshwaters. We found that all three factors influence land use-lake nutrient relationships. The strongest evidence was for the effect of lake hydrologic connectivity, followed by region, and finally, the spatial extent of land use measurements. Incorporating these three factors into relatively simple models of land use effects on lake nutrients should help to improve predictions and understanding of land use-lake nutrient interactions at broad scales.

Regional pattern of snow characteristics around Antarctic Lake Vostok

Science.gov (United States)

Vladimirova, Diana; Ekaykin, Alexey; Popov, Sergey; Shibaev, Yuriy; Kozachek, Anna; Lipenkov, Vladimir

2015-04-01

Since 1998 Russian Antarctic Expedition has organized several scientific traverses in the region of subglacial Lake Vostok mainly devoted to the radar echo and seismic sounding of the glacier and water (the results have been published elsewhere). Along with the geophysical studies, a number of glaciological investigations have been carried out: snow pit digging, installation of accumulation stakes, snow sampling to study the stable water isotope content. Here we for the first time present a synthesis of these works and demonstrate a series of maps that characterize the snow density, isotope content and accumulation rate the studied region. A general tendency of the snow accumulation rate and isotope content is a significant increase from south (south-west) to north (north-east) from 35 to 23 mm w.e. per year and from -53,3 ‰ to -57,3 ‰ for delta oxygen-18 respectively, which likely reflects the continental-scale pattern, i.e., increase from inland to the coast. Deuterium excess varies from 11,7 ‰ to 16,3 ‰ is negatively correlated with the isotope content, which is typical for central Antarctica. The snow density demonstrate different pattern: higher values offshore the lake (up to 0,356 g/cm^3), and lower values within the lake's shoreline (lower limit is 0,328 g/cm^3). We suggest that this is related to the katabatic wind activity: very flat nearly horizontal surface of the glacier above the lake is not favorable for the strong winds, which leads to lower surface snow density. Superimposed on the main trend is the regional pattern, namely, curved contour lines in the middle part of the lake. We suggest that it may be related to the local anomalies of the snow drift by wind. Indeed, on the satellite images of the lake one can easily see a snowdrift stretching from the lake's western shore downwind in the middle part of the lake. The isolines of delta oxygen-18 and deuterium excess become perpendicular to each other in the north part of the lake which also

Estructura comunitaria de diatomeas presentes en los sedimentos superficiales de ocho lagos andinos de Chile central Diatoms community structure in superficial sediments of eight Andean lakes of central Chile

Directory of Open Access Journals (Sweden)

INGRID E ALVIAL

2008-03-01

Full Text Available En este trabajo se analizó la estructura comunitaria de diatomeas depositadas en los sedimentos superficiales de ocho lagos andinos chilenos ubicados entre los 32°49' y 38°48' S. Se encontró un total de 99 taxa de diatomeas, distribuidos en 48 géneros. Del total de taxa, 74 fueron identificados a nivel de especie siendo todos ellos cosmopolitas a excepción de Eunotia andinofrequens, Gomphonema punae, Pinnularia araucanensis y Pinnularia acidicola, entre otras, que están descritos solo para el Hemisferio Sur. Por otro lado, las muestras analizadas presentaron distinta composición florística de diatomeas. De esta manera, en los ensambles diatomológicos depositados en los sedimentos de las lagunas de altura Ocho, Huifa, Ensueño y Negra ubicadas sobre los 2.860 m del nivel del mar, abundaron especies bentónicas, típicas de aguas oligotróficas y acidas como Achnanthidium exiguum, Achnanthidium minutissimum, Encyonema minutum, Pinnularia acidicola y Planothidium lanceolatum. En los ensambles diatomológicos de los lagos Galletué, Icalma y Laja, ubicados bajo los 1.360 m del nivel del mar, abundaron diatomeas planctónicas, características de aguas alcalinas y mesotróficas como Asterionella formosa, Aulacoseira distans, Aulacoseira granulata, Cyclotella stelligera y Rhopalodia gibbaIn this research the taxonomic structure of diatoms in sediments of high mountain lakes was studied. These lakes are located in Chile between 32°49' and 38°48' S in the Andean Cordillera. A total of 99 diatom taxa distributed in 48 genera were identified and all this taxa are cosmopolitan excepting a Eunotia andinofrequens, Gomphonema punae, Pinnularia araucanensis and Pinnularia acidicola, which are know only for the Southern Hemisphere. The assemblages of diatoms were different in the studied lakes. So the high mountain lakes Ocho, Huifa, Ensueño and Negra, dominated benthic diatoms which are typical of oligotrophic and acid waters as Achnanthidium

PeRL: a circum-Arctic Permafrost Region Pond and Lake database

Science.gov (United States)

Muster, Sina; Roth, Kurt; Langer, Moritz; Lange, Stephan; Cresto Aleina, Fabio; Bartsch, Annett; Morgenstern, Anne; Grosse, Guido; Jones, Benjamin; Sannel, A. Britta K.; Sjöberg, Ylva; Günther, Frank; Andresen, Christian; Veremeeva, Alexandra; Lindgren, Prajna R.; Bouchard, Frédéric; Lara, Mark J.; Fortier, Daniel; Charbonneau, Simon; Virtanen, Tarmo A.; Hugelius, Gustaf; Palmtag, Juri; Siewert, Matthias B.; Riley, William J.; Koven, Charles D.; Boike, Julia

2017-06-01

Ponds and lakes are abundant in Arctic permafrost lowlands. They play an important role in Arctic wetland ecosystems by regulating carbon, water, and energy fluxes and providing freshwater habitats. However, ponds, i.e., waterbodies with surface areas smaller than 1. 0 × 104 m2, have not been inventoried on global and regional scales. The Permafrost Region Pond and Lake (PeRL) database presents the results of a circum-Arctic effort to map ponds and lakes from modern (2002-2013) high-resolution aerial and satellite imagery with a resolution of 5 m or better. The database also includes historical imagery from 1948 to 1965 with a resolution of 6 m or better. PeRL includes 69 maps covering a wide range of environmental conditions from tundra to boreal regions and from continuous to discontinuous permafrost zones. Waterbody maps are linked to regional permafrost landscape maps which provide information on permafrost extent, ground ice volume, geology, and lithology. This paper describes waterbody classification and accuracy, and presents statistics of waterbody distribution for each site. Maps of permafrost landscapes in Alaska, Canada, and Russia are used to extrapolate waterbody statistics from the site level to regional landscape units. PeRL presents pond and lake estimates for a total area of 1. 4 × 106 km2 across the Arctic, about 17 % of the Arctic lowland ( pangaea.de/10.1594/PANGAEA.868349" target="_blank">https://doi.pangaea.de/10.1594/PANGAEA.868349.

[Ecological compensation standard in Dongting Lake region of returning cropland to lake based on emergy analysis].

Science.gov (United States)

Mao, De-Hua; Hu, Guang-Wei; Liu, Hui-Jie; Li, Zheng-Zui; Li, Zhi-Long; Tan, Zi-Fang

2014-02-01

The annual emergy and currency value of the main ecological service value of returning cropland to lake in Dongting Lake region from 1999 to 2010 was calculated based on emergy analysis. The calculation method of ecological compensation standard was established by calculating annual total emergy of ecological service function increment since the starting year of returning cropland to lake, and the annual ecological compensation standard and compensation area were analyzed from 1999 to 2010. The results indicated that ecological compensation standard from 1999 to 2010 was 40.31-86.48 yuan x m(-2) with the mean of 57.33 yuan x m(-2). The ecological compensation standard presented an increase trend year by year due to the effect of eco-recovery of returning cropland to lake. The ecological compensation standard in the research area presented a swift and steady growth trend after 2005 mainly due to the intensive economy development of Hunan Province, suggesting the value of natural ecological resources would increase along with the development of society and economy. Appling the emergy analysis to research the ecological compensation standard could reveal the dynamics of annual ecological compensation standard, solve the abutment problem of matter flow, energy flow and economic flow, and overcome the subjective and arbitrary of environment economic methods. The empirical research of ecological compensation standard in Dongting Lake region showed that the emergy analysis was feasible and advanced.

Hydrogeochemical evaluation of conventional and hot dry rock geothermal resource potential in the Clear Lake region, California

Energy Technology Data Exchange (ETDEWEB)

Goff, F.; Adams, A.I.; Trujillo, P.E.; Counce, D.

1993-05-01

Chemistry, stable isotope, and tritium contents of thermal/mineral waters in the Clear Lake region were used to evaluate conventional and hot dry rock (HDR) geothermal potential for electrical generation. Thermal/mineral waters of the Clear Lake region are broadly classified as thermal meteoric and connate types based on chemical and isotopic criteria. Ratios of conservative components such as B/Cl are extremely different among all thermal/mineral waters of the Clear Lake region except for clusters of waters emerging from specific areas such as the Wilbur Springs district and the Agricultural Park area south of Mt. Konocti. In contrast ratios of conservative components in large, homogeneous geothermal reservoirs are constant. Stable isotope values of Clear Lake region waters show a mixing trend between thermal meteoric and connate (generic) end-members. The latter end-member has enriched {delta}D as well as enriched {delta}{sup 18}O, from typical high-temperature geothermal reservoir waters. Tritium data indicate most Clear Lake region waters are mixtures of old and young fluid components. Subsurface equilibration temperature of most thermal/mineral waters of the Clear Lake region is {le}150{degree}C based on chemical geothermometers but it is recognized that Clear Lake region waters are not typical geothermal fluids and that they violate rules of application of many geothermometers. The combined data indicate that no large geothermal reservoir underlies the Clear Lake region and that small localized reservoirs have equilibration temperatures {le}150{degree}C (except for Sulphur Bank mine). HDR technologies are probably the best way to commercially exploit the known high-temperatures existing beneath the Clear Lake region particularly within and near the main Clear Lake volcanic field.

Lake nutrient stoichiometry is less predictable than nutrient concentrations at regional and sub-continental scales.

Science.gov (United States)

Collins, Sarah M; Oliver, Samantha K; Lapierre, Jean-Francois; Stanley, Emily H; Jones, John R; Wagner, Tyler; Soranno, Patricia A

2017-07-01

Production in many ecosystems is co-limited by multiple elements. While a known suite of drivers associated with nutrient sources, nutrient transport, and internal processing controls concentrations of phosphorus (P) and nitrogen (N) in lakes, much less is known about whether the drivers of single nutrient concentrations can also explain spatial or temporal variation in lake N:P stoichiometry. Predicting stoichiometry might be more complex than predicting concentrations of individual elements because some drivers have similar relationships with N and P, leading to a weak relationship with their ratio. Further, the dominant controls on elemental concentrations likely vary across regions, resulting in context dependent relationships between drivers, lake nutrients and their ratios. Here, we examine whether known drivers of N and P concentrations can explain variation in N:P stoichiometry, and whether explaining variation in stoichiometry differs across regions. We examined drivers of N:P in ~2,700 lakes at a sub-continental scale and two large regions nested within the sub-continental study area that have contrasting ecological context, including differences in the dominant type of land cover (agriculture vs. forest). At the sub-continental scale, lake nutrient concentrations were correlated with nutrient loading and lake internal processing, but stoichiometry was only weakly correlated to drivers of lake nutrients. At the regional scale, drivers that explained variation in nutrients and stoichiometry differed between regions. In the Midwestern U.S. region, dominated by agricultural land use, lake depth and the percentage of row crop agriculture were strong predictors of stoichiometry because only phosphorus was related to lake depth and only nitrogen was related to the percentage of row crop agriculture. In contrast, all drivers were related to N and P in similar ways in the Northeastern U.S. region, leading to weak relationships between drivers and stoichiometry

Regional groundwater-flow model of the Lake Michigan Basin in support of Great Lakes Basin water availability and use studies

Science.gov (United States)

Feinstein, D.T.; Hunt, R.J.; Reeves, H.W.

2010-01-01

A regional groundwater-flow model of the Lake Michigan Basin and surrounding areas has been developed in support of the Great Lakes Basin Pilot project under the U.S. Geological Survey's National Water Availability and Use Program. The transient 2-million-cell model incorporates multiple aquifers and pumping centers that create water-level drawdown that extends into deep saline waters. The 20-layer model simulates the exchange between a dense surface-water network and heterogeneous glacial deposits overlying stratified bedrock of the Wisconsin/Kankakee Arches and Michigan Basin in the Lower and Upper Peninsulas of Michigan; eastern Wisconsin; northern Indiana; and northeastern Illinois. The model is used to quantify changes in the groundwater system in response to pumping and variations in recharge from 1864 to 2005. Model results quantify the sources of water to major pumping centers, illustrate the dynamics of the groundwater system, and yield measures of water availability useful for water-resources management in the region. This report is a complete description of the methods and datasets used to develop the regional model, the underlying conceptual model, and model inputs, including specified values of material properties and the assignment of external and internal boundary conditions. The report also documents the application of the SEAWAT-2000 program for variable-density flow; it details the approach, advanced methods, and results associated with calibration through nonlinear regression using the PEST program; presents the water-level, drawdown, and groundwater flows for various geographic subregions and aquifer systems; and provides analyses of the effects of pumping from shallow and deep wells on sources of water to wells, the migration of groundwater divides, and direct and indirect groundwater discharge to Lake Michigan. The report considers the role of unconfined conditions at the regional scale as well as the influence of salinity on groundwater flow

Ecomicrobiology and microbial assimilative capacity of the oligotrophic Andean Lake Laja, Chile Ecomicrobiología y capacidad asimilativa microbiana del lago oligotrófico andino Laja, Chile

Directory of Open Access Journals (Sweden)

BERNHARD KARRASCH

2011-09-01

Full Text Available A strong socio-economic development pressure in South Chile will more and more cause an impact to the present lakes and rivers. Nevertheless, our knowledge concerning the ecological structure and the microbial self-purification capabilities of these lacustrine water bodies is scant but essential for a future sustainable development of land and water use. We studied Lake Laja, a lake already heavily impacted by water diversions for hydropower generation and irrigation. Typical for the Andean region Lake Laja is an oligotrophic water body, limited by nitrogen nutrients. Only very low chlorophyll a and particulate organic carbon (POC concentrations and a small abundance and biomass of bacteria (mainly ultramicrobacteria and heterotrophic flagellates were encountered. Weak trophic interrelations were derived from a high bacteria-to-heterotrophic flagellate ratio. For the ten investigated extracellular enzymes (alkaline phosphatase, leucine, arginine-, glycine and tyrosine-aminopeptidase, α-, β-D-glucosidase, α-, β-D-galactosidase, N-acetyl-β-D-glucosaminidase, with the exception of α-D-glucosidase, a broad range of organic matter degradation activities was proven. Probably, due to the N-limitation, organic nitrogen hydrolysing extracellular enzymes reached activities on average of 45 % compared to other studies in oligotrophic waters. The possible effect of N-limitation on extracellular enzyme activities was more pronounced by cell specific extracellular enzymatic activity rates, which exceeded those of other oligotrophic water bodies on average by factor 2. The overall activities of all microbial extracellular enzymes studied proved to be dominated by the dissolved free external enzymes (up to 98 % over the ectoenzymes which are associated with particulate organic matter (bacterial cell walls, particles, and aggregates. It is concluded that future socio-economic changes, dealing with watershed human intervention (accelerating inorganic and

Evidence for regional nitrogen stress on chlorophyll a in lakes across large landscape and climate gradients

Science.gov (United States)

Filstrup, Christopher T.; Wagner, Tyler; Oliver, Samantha K.; Stow, Craig A.; Webster, Katherine E.; Stanley, Emily H.; Downing, John A.

2018-01-01

Nitrogen (N) and phosphorus (P) commonly stimulate phytoplankton production in lakes, but recent observations from lakes from an agricultural region suggest that nitrate may have a subsidy‐stress effect on chlorophyll a (Chl a). It is unclear, however, how generalizable this effect might be. Here, we analyzed a large water quality dataset of 2385 lakes spanning 60 regions across 17 states in the Northeastern and Midwestern U.S. to determine if N subsidy‐stress effects on phytoplankton are common and to identify regional landscape characteristics promoting N stress effects in lakes. We used a Bayesian hierarchical modeling framework to test our hypothesis that Chl a–total N (TN) threshold relationships would be common across the central agricultural region of the U.S. (“the Corn Belt”), where lake N and P concentrations are high. Data aggregated across all regions indicated that high TN concentrations had a negative effect on Chl a in lakes with concurrent high total P. This large‐scale pattern was driven by relationships within only a subset of regions, however. Eight regions were identified as having Chl a–TN threshold relationships, but only two of these regions located within the Corn Belt clearly demonstrated this subsidy‐stress relationship. N stress effects were not consistent across other intense agricultural regions, as we hypothesized. These findings suggest that interactions among regional land use and land cover, climate, and hydrogeology may be important in determining the synergistic conditions leading to N subsidy‐stress effects on lake phytoplankton.

Great Lakes Regional Biomass Energy Program

International Nuclear Information System (INIS)

Kuzel, F.

1993-01-01

The Great Lakes Regional Biomass Energy Program (GLRBEP) was initiated September, 1983, with a grant from the Office of Energy Efficiency and Renewable Energy of the US Department of Energy (DOE). The program provides resources to public and private organizations in the Great Lakes region to increase the utilization and production of biomass fuels. The objectives of the GLRBEP are to: (1) improve the capabilities and effectiveness of biomass energy programs in the state energy offices; (2) assess the availability of biomass resources for energy in light of other competing needs and uses; (3) encourage private sector investments in biomass energy technologies; (4) transfer the results of government-sponsored biomass research and development to the private sector; (5) eliminate or reduce barriers to private sector use of biomass fuels and technology; (6) prevent or substantially mitigate adverse environmental impacts of biomass energy use. The Program Director is responsible for the day-to-day activities of the GLRBEP and for implementing program mandates. A 40 member Technical Advisory Committee (TAC) sets priorities and recommends projects. The governor of each state in the region appoints a member to the Steering Council, which acts on recommendations of the TAC and sets basic program guidelines. The GLRBEP is divided into three separate operational elements. The State Grants component provides funds and direction to the seven state energy offices in the region to increase their capabilities in biomass energy. State-specific activities and interagency programs are emphasized. The Subcontractor component involves the issuance of solicitations to undertake projects that address regional needs, identified by the Technical Advisory Committee. The Technology Transfer component includes the development of nontechnical biomass energy publications and reports by Council staff and contractors, and the dissemination of information at conferences, workshops and other events

Hydrograph Predictions of Glacial Lake Outburst Floods From an Ice-Dammed Lake

Science.gov (United States)

McCoy, S. W.; Jacquet, J.; McGrath, D.; Koschitzki, R.; Okuinghttons, J.

2017-12-01

Understanding the time evolution of glacial lake outburst floods (GLOFs), and ultimately predicting peak discharge, is crucial to mitigating the impacts of GLOFs on downstream communities and understanding concomitant surface change. The dearth of in situ measurements taken during GLOFs has left many GLOF models currently in use untested. Here we present a dataset of 13 GLOFs from Lago Cachet Dos, Aysen Region, Chile in which we detail measurements of key environmental variables (total volume drained, lake temperature, and lake inflow rate) and high temporal resolution discharge measurements at the source lake, in addition to well-constrained ice thickness and bedrock topography. Using this dataset we test two common empirical equations as well as the physically-based model of Spring-Hutter-Clarke. We find that the commonly used empirical relationships based solely on a dataset of lake volume drained fail to predict the large variability in observed peak discharges from Lago Cachet Dos. This disagreement is likely because these equations do not consider additional environmental variables that we show also control peak discharge, primarily, lake water temperature and the rate of meltwater inflow to the source lake. We find that the Spring-Hutter-Clarke model can accurately simulate the exponentially rising hydrographs that are characteristic of ice-dammed GLOFs, as well as the order of magnitude variation in peak discharge between events if the hydraulic roughness parameter is allowed to be a free fitting parameter. However, the Spring-Hutter-Clarke model over predicts peak discharge in all cases by 10 to 35%. The systematic over prediction of peak discharge by the model is related to its abrupt flood termination that misses the observed steep falling limb of the flood hydrograph. Although satisfactory model fits are produced, the range in hydraulic roughness required to obtain these fits across all events was large, which suggests that current models do not

La negociación centro-región en Chile: realidad o mito - el caso de la región de Los Lagos Central-regional negotiation in Chile: reality or myth - the case of the Los Lagos region

Directory of Open Access Journals (Sweden)

Pablo Aurelio Monje Reyes

2007-08-01

Full Text Available A partir de la década de los 1990, la descentralización política-administrativa de Chile se ha profundizado en forma gradual. Ello se ha expresado, entre otros aspectos, en la creación de gobiernos regionales y en la disposición política del gobierno central de dejar en manos de estas instancias el manejo de recursos para la inversión regional. No obstante, la reconfiguración de la actual división de las regiones no se ha tomado como un tema prioritario dentro de la política descentralizadora en cuestión. Sin embargo, ello no ha implicado que se esté obviando el tema por completo; ya que a nivel extraoficial, y de parte tanto del gobierno central como regional, se plantea la necesidad de hacer una propuesta de reestructuración de la división política-administrativa del país. Este estudio de caso fija su atención en las demandas de reestructuración recién mencionadas, haciendo especial hincapié en la observación del fenómeno de demanda por la regionalización de la provincia de Valdivia, en la décima región de Los Lagos, Chile, durante los años 1995/96. Dicho trabajo se realizó bajo la óptica de la negociación centro-región, con los objetivos de describir los componentes del proceso y de reconocer las condicionantes de las acciones de los actores en el mismo. Los resultados del estudio están vinculados al rol que ejercen los actores en el conflicto y negociación centro-región. Se consiguió realizar una caracterización de ellos, además de constatar la relación de clientela política que se produce entre la elite nacional y regional, como factor determinante en el resultado de la negociación. De la misma manera, se comprobó que el diseño institucional del sistema político induce este tipo de vínculo entre las elites mencionadas. Finalmente, el estudio presenta una serie de recomendaciones para el fortalecimiento de la política pública de descentralización de Chile, que están en marco de aminorar los

Lake Morphometry for NHD Lakes in Great Lakes Region 4 HUC

Data.gov (United States)

U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

Understanding Obstacles to Peace in the Great Lakes Region ...

International Development Research Centre (IDRC) Digital Library (Canada)

Africa's Great Lakes region is home to violent and prolonged conflicts that cause a lot of suffering and block socioeconomic progress. Several initiatives are underway to bring peace to the region. But, most of these focus on specific countries and have not taken into account the interrelated and overlapping nature of the ...

How much acidification has occurred in Adirondack region lakes (New York, USA) since preindustrial times

International Nuclear Information System (INIS)

Cumming, B.F.; Smol, J.P.; Kingston, J.C.; Charles, D.F.; Birks, H.J.B.

1992-01-01

Preindustrial and present-day lake water pH, acid neutralizing capacity (ANC), total monomeric aluminum Al(sub m), and dissolved organic carbon (DOC) were inferred from the species composition of diatom and chrysophyte microfossils in the tops (present-day inferences) and bottoms (pre-1850 inferences) of sediment cores collected from a statistically selected set of Adirondack lakes. Results from the study lakes were extrapolated to a predefined target population of 675 low-alkalinity Adirondack region lakes. Estimates of preindustrial to present-day changes in lake water chemistry show that approximately 25-35% of the target population has acidified. The magnitude of acidification was greatest in the low-alkalinity lakes of the southwestern Adirondacks, an area with little geological ability to neutralize acidic deposition and receives the highest annual average rainfall in the region. The authors estimate that approximately 80% of the target population lakes with present-day measured pH = or < 5.2 and 30-45% of lakes with pH between 5.2 and 6.0 have undergone large declines in pH and ANC, and concomitant increases in Al(sub m). Estimated changes in (DOC) were small and show no consistent pattern in the acidified lakes. The study provides the first statistically based regional evaluation of the extent of lake acidification in the Adirondacks

Chile.

Science.gov (United States)

1992-05-01

The background notes on Chile provide a statistical summary of the population, geography, government, and the economy, and more descriptive text on the history, population, government, economy, defense, and foreign relations. In brief, Chile has 13.3 million Spanish Indian (Mestizos), European, and Indian inhabitants and an annual growth rate of 1.6%. 96% are literate. Infant mortality is 18/1000. 34% of the population are involved in industry and commerce, 30% in services, 19% in agriculture and forestry and fishing, 7% in construction, and 2% in mining. The major city is Santiago. The government, which gained independence in 1810, is a republic with executive, legislative, and judicial branches. There are 12 regions. There are 6 major political parties. Suffrage is universal at 18 years. Gross domestic product (GDP) is $29.2 billion. The annual growth rate is 5% and inflation is 19%. Copper, timber, fish, iron ore, nitrates, precious metals, and molybdenum are its natural resources. Agricultural products are 9% of GDP and include wheat, potatoes, corn, sugar beets, onions, beans, fruits, and livestock. Industry is 21% of GDP and includes mineral refining, metal manufacturing, food and fish processing, paper and wood products, and finished textiles. $8.3 billion is the value of exports and $7 billion of imports. Export markets are in Japan, the US, Germany, Brazil, and the United Kingdom. Chile received $3.5 billion in economic aid between 1949-85, but little in recent years. 83% live in urban centers, principally around Santiago. Congressional representation is made on the basis of elections by a unique binomial majority system. Principal government officials are identified. Chile has a diversified free market economy and is almost self-sufficient in food production. The US is a primary trading partner. 49% of Chile's exports are minerals. Chile maintains diplomatic relations with 70 countries, however, relations are strained with Argentina and Bolivia. Relations

Seasonal climatology of hydrographic conditions in the upwelling region off northern Chile

Science.gov (United States)

Blanco, J. L.; Thomas, A. C.; Carr, M.-E.; Strub, P. T.

2001-06-01

Over 30 years of hydrographic data from the northern Chile (18°S-24°S) upwelling region are used to calculate the surface and subsurface seasonal climatology extending 400 km offshore. The data are interpolated to a grid with sufficient spatial resolution to preserve cross-shelf gradients and then presented as means within four seasons: austral winter (July-September), spring (October-December), summer (January-March), and fall (April-June). Climatological monthly wind forcing, surface temperature, and sea level from three coastal stations indicate equatorward (upwelling favorable) winds throughout the year, weakest in the north. Seasonal maximum alongshore wind stress is in late spring and summer (December-March). Major water masses of the region are identified in climatological T-S plots and their sources and implied circulation discussed. Surface fields and vertical transects of temperature and salinity confirm that upwelling occurs year-round, strongest in summer and weakest in winter, bringing relatively fresh water to the surface nearshore. Surface geostrophic flow nearshore is equatorward throughout the year. During summer, an anticyclonic circulation feature in the north which extends to at least 200 m depth is evident in geopotential anomaly and in both temperature and geopotential variance fields. Subsurface fields indicate generally poleward flow throughout the year, strongest in an undercurrent near the coast. This undercurrent is strongest in summer and most persistent and organized in the south (south of 21°S). A subsurface oxygen minimum, centered at ˜250 m, is strongest at lower latitudes. Low-salinity subsurface water intrudes into the study area near 100 m, predominantly in offshore regions, strongest during summer and fall and in the southernmost portion of the region. The climatological fields are compared to features off Baja within the somewhat analogous California Current and to measurements from higher latitudes within the Chile

Heavy metals in bottom sediments of Lake Umbozero in Murmansk Region, Russia

DEFF Research Database (Denmark)

Jernström, Jussi; Lehto, J.; Dauvalter, A.

2010-01-01

Sediment cores collected from different locations of Lake Umbozero were studied with respect to concentration and mobility of trace and heavy metals Co, Cu, Fe, Mn, Ni, Pb, U, and Zn. Lake Umbozero is the second largest lake in the Murmansk Region and subjected to contamination by air......-borne emissions and river transportation from the nearby metallurgical and mining industries. Unlike its neighboring, more industry-prone Lake Imandra, Lake Umbozero is relatively unexplored with respect to its state of pollution. In our study, metal distribution in sediments was found to vary with respect...... in lakes of Kola Peninsula located further off from industrial pollutant sources. An exception was Pb the concentration of which was at the same level as in Lake Imandra, probably due to long-distance transport. Sediment layers were subjected to four-step sequential extraction procedure to reveal the metal...

Simulation of Lake Victoria Circulation Patterns Using the Regional Ocean Modeling System (ROMS.

Directory of Open Access Journals (Sweden)

Chrispine Nyamweya

Full Text Available Lake Victoria provides important ecosystem services including transport, water for domestic and industrial uses and fisheries to about 33 million inhabitants in three East African countries. The lake plays an important role in modulating regional climate. Its thermodynamics and hydrodynamics are also influenced by prevailing climatic and weather conditions on diel, seasonal and annual scales. However, information on water temperature and circulation in the lake is limited in space and time. We use a Regional Oceanographic Model System (ROMS to simulate these processes from 1st January 2000 to 31st December 2014. The model is based on real bathymetry, river runoff and atmospheric forcing data using the bulk flux algorithm. Simulations show that the water column exhibits annual cycles of thermo-stratification (September-May and mixing (June-August. Surface water currents take different patterns ranging from a lake-wide northward flow to gyres that vary in size and number. An under flow exists that leads to the formation of upwelling and downwelling regions. Current velocities are highest at the center of the lake and on the western inshore waters indicating enhanced water circulation in those areas. However, there is little exchange of water between the major gulfs (especially Nyanza and the open lake, a factor that could be responsible for the different water quality reported in those regions. Findings of the present study enhance understanding of the physical processes (temperature and currents that have an effect on diel, seasonal, and annual variations in stratification, vertical mixing, inshore-offshore exchanges and fluxes of nutrients that ultimately influence the biotic distribution and trophic structure. For instance information on areas/timing of upwelling and vertical mixing obtained from this study will help predict locations/seasons of high primary production and ultimately fisheries productivity in Lake Victoria.

Simulation of Lake Victoria Circulation Patterns Using the Regional Ocean Modeling System (ROMS).

Science.gov (United States)

Nyamweya, Chrispine; Desjardins, Christopher; Sigurdsson, Sven; Tomasson, Tumi; Taabu-Munyaho, Anthony; Sitoki, Lewis; Stefansson, Gunnar

2016-01-01

Lake Victoria provides important ecosystem services including transport, water for domestic and industrial uses and fisheries to about 33 million inhabitants in three East African countries. The lake plays an important role in modulating regional climate. Its thermodynamics and hydrodynamics are also influenced by prevailing climatic and weather conditions on diel, seasonal and annual scales. However, information on water temperature and circulation in the lake is limited in space and time. We use a Regional Oceanographic Model System (ROMS) to simulate these processes from 1st January 2000 to 31st December 2014. The model is based on real bathymetry, river runoff and atmospheric forcing data using the bulk flux algorithm. Simulations show that the water column exhibits annual cycles of thermo-stratification (September-May) and mixing (June-August). Surface water currents take different patterns ranging from a lake-wide northward flow to gyres that vary in size and number. An under flow exists that leads to the formation of upwelling and downwelling regions. Current velocities are highest at the center of the lake and on the western inshore waters indicating enhanced water circulation in those areas. However, there is little exchange of water between the major gulfs (especially Nyanza) and the open lake, a factor that could be responsible for the different water quality reported in those regions. Findings of the present study enhance understanding of the physical processes (temperature and currents) that have an effect on diel, seasonal, and annual variations in stratification, vertical mixing, inshore-offshore exchanges and fluxes of nutrients that ultimately influence the biotic distribution and trophic structure. For instance information on areas/timing of upwelling and vertical mixing obtained from this study will help predict locations/seasons of high primary production and ultimately fisheries productivity in Lake Victoria.

International Uranium Resources Evaluation Project (IUREP) national favourability studies: Chile

International Nuclear Information System (INIS)

1977-08-01

Chile has an area of 740,760 square kilometers. The capital is Santiago. The country is 4,183 km. long and ranges from 22.5 to about 354 km. in width. Its chief topographic features para]lei each other - the Coastal Range, Andes Mountains and Central Valley. The Coastal Range rises to 2,130 meters in the north, but averages from 610 to 700 meters high generally. The range plunges into the Pacific Ocean far south of Valparaiso and reappears in the southern archipelagic islands. The Andes extend along nearly the entire length of Chile and contain 100 volcanoes. Andean peaks range mostly from 3,000 to 6,700 meters in elevation. In southern Chile the Andes are lower, and contain about a dozen major lakes. The mountains disappear in Chilean Patagonia, but reappear at Cape Horn. The Central Valley lies between the Coastal Range and the Andes, being best defined in the midland region as a 64 to 72 km sloping plain. It is the Chilean heartland with three-quarters of the country's population. Salt basins are found over much of northern Chile in the very arid desert, while the region south of the Gulf of Reloncavi consists of unpopulated islands, fjords, channels and heavily forested mountains. The Strait of Magellan, the Tierra del Fuego archipelago and a flat grassland area make up the extreme southern end of the country. Much of Chile is subject to flash floods, earthquakes, volcanic eruptions, landslides and avalanches. In September 1976 the Comision Chilena de Energia Nuclear (CCEN) was given exclusive rights to negotiate contracts with private companies for the exploration, development and mining of uranium and other radioactive minerals. The new law provides the CCEN with considerable flexibility in the terms of the contracts. Pre-964 owners of uranium deposits may reach agreements with foreign companies to mine the uranium, but since 1964 all uranium has belonged to the state. Uranium produced in the country can only be exported after Chile's needs have been met. The

Hydroclimatic variability in the Lake Mondsee region and its relationships with large-scale climate anomaly patterns

Science.gov (United States)

Rimbu, Norel; Ionita, Monica; Swierczynski, Tina; Brauer, Achim; Kämpf, Lucas; Czymzik, Markus

2017-04-01

Flood triggered detrital layers in varved sediments of Lake Mondsee, located at the northern fringe of the European Alps (47°48'N,13°23'E), provide an important archive of regional hydroclimatic variability during the mid- to late Holocene. To improve the interpretation of the flood layer record in terms of large-scale climate variability, we investigate the relationships between observational hydrological records from the region, like the Mondsee lake level, the runoff of the lake's main inflow Griesler Ache, with observed precipitation and global climate patterns. The lake level shows a strong positive linear trend during the observational period in all seasons. Additionally, lake level presents important interannual to multidecadal variations. These variations are associated with distinct seasonal atmospheric circulation patterns. A pronounced anomalous anticyclonic center over the Iberian Peninsula is associated with high lake levels values during winter. This center moves southwestward during spring, summer and autumn. In the same time, a cyclonic anomaly center is recorded over central and western Europe. This anomalous circulation extends southwestward from winter to autumn. Similar atmospheric circulation patterns are associated with river runoff and precipitation variability from the region. High lake levels are associated with positive local precipitation anomalies in all seasons as well as with negative local temperature anomalies during spring, summer and autumn. A correlation analysis reveals that lake level, runoff and precipitation variability is related to large-scale sea surface temperature anomaly patterns in all seasons suggesting a possible impact of large-scale climatic modes, like the North Atlantic Oscillation and Atlantic Multidecadal Oscillation on hydroclimatic variability in the Lake Mondsee region. The results presented in this study can be used for a more robust interpretation of the long flood layer record from Lake Mondsee sediments

Evaluation of regional climate simulations over the Great Lakes region driven by three global data sets

Science.gov (United States)

Shiyuan Zhong; Xiuping Li; Xindi Bian; Warren E. Heilman; L. Ruby Leung; William I. Jr. Gustafson

2012-01-01

The performance of regional climate simulations is evaluated for the Great Lakes region. Three 10-year (1990-1999) current-climate simulations are performed using the MM5 regional climate model (RCM) with 36-km horizontal resolution. The simulations employed identical configuration and physical parameterizations, but different lateral boundary conditions and sea-...

Monitoring lake level changes by altimetry in the arid region of Central Asia

Science.gov (United States)

Zhao, Y.; Liao, J. J.; Shen, G. Z.; Zhang, X. L.

2017-07-01

The study of lake level changes in arid region of Central Asia not only has important significance for the management and sustainable development of inland water resources, but also provides the basis for further study on the response of lakes to climate change and human activities. Therefore, in this paper, eleven typical lakes in Central Asia were observed. The lake edges were obtained through image interpretation using the quasi-synchronous MODIS image, and then water level information with long period (2002-2015) was acquired using ENVISAT/RA-2 and Cryosat-2 satellite borne radar altimeter data. The results show that these 11 lakes all have obvious seasonal changes of water level in a year with a high peak at different month. During 2002 - 2015, their water levels present decreased trend generally except Sarygamysh Lake, Alakol Lake and North Aral Sea. The alpine lakes are most stables, while open lakes’ levels change the most violently and closed lakes change diversely among different lakes.

Paleogeography of the Austro-Hungarian Lake Neusiedl - Hansag region in historic times, based on 14C-dating

International Nuclear Information System (INIS)

Haeusler, H.; Sauermann, I.; Kovacs, G.; Wild, E.; Steiner, P.

2007-01-01

Full text: Based on calibrated 14 C-dating of several peat sections intercalating with fine-grained beds in the Hansag southeast of Lake Neusiedl we present a first approach of the paleogeography of the Austro-Hungarian border region during a time span when first settlements already existed and before the first detailed topographic maps of this region were drawn. About one hundred pits down to one metre were digged out in the Hansag region near Osli in 2003 for studying the recultivation of this regularly flooded area in an environmental geo-information system (GIS). Several sections clearly show an alternation of peat layers intersected by fine-grained fluvio-lacustrine sediments. 15 age determinations of samples from several sections underlying and overlying silty to clayey sediments allow for reconstructing the succession of longer stillwater deposits alternating with peat successions. Comparing the Hansag succession with historic records of the vicinity of Lake Neusiedl allows for a new insight in this unique development of the Lake Neusiedl - Hansag region, at present situated within the Austro-Hungarian national park. It should be recalled, that Lake Neusiedl is Central Europe's largest step lake and Austria's youngest UNESCO World Cultural Heritage site. The paleo-environment of the Lake Neusiedl - Hansag region basically can be designed in four steps by comparing the archaeological findings around Lake Neusiedl with our 14 C-dating of peat layers in the Hansag region: 1: the oldest settlements in the Lake Neusiedl region date about 3600 BC, and 1700 BC respectively. During this periods the lake probably was quite smaller than today. Our 14 C-dating of peat sections in the Hansag region corresponds with these findings, indicating that during a time span of approximately 2000 years until 30 Anno Domini (AD) no bigger lake existed in the Neusiedl- Hansag region. Small pieces of charcoal dating around 2300 BC can have been caused by bush fire and therefore be

Lake seasonality across the Tibetan Plateau and their varying relationship with regional mass changes and local hydrology

Science.gov (United States)

Lei, Yanbin; Yao, Tandong; Yang, Kun; Sheng, Yongwei; Kleinherenbrink, Marcel; Yi, Shuang; Bird, Broxton W.; Zhang, Xiaowen; Zhu, La; Zhang, Guoqing

2017-01-01

The recent growth and deepening of inland lakes in the Tibetan Plateau (TP) may be a salient indicator of the consequences of climate change. The seasonal dynamics of these lakes is poorly understood despite this being potentially crucial for disentangling contributions from glacier melt and precipitation, which are all sensitive to climate, to lake water budget. Using in situ observations, satellite altimetry and gravimetry data, we identified two patterns of lake level seasonality. In the central, northern, and northeastern TP, lake levels are characterized by considerable increases during warm seasons and decreases during cold seasons, which is consistent with regional mass changes related to monsoon precipitation and evaporation. In the northwestern TP, however, lake levels exhibit dramatic increases during both warm and cold seasons, which deviate from regional mass changes. This appears to be more connected with high spring snowfall and large summer glacier melt. The variable lake level response to different drivers indicates heterogeneous sensitivity to climate change between the northwestern TP and other regions.

ASTER measurement of supraglacial lakes in the Mount Everest region of the Himalaya

Science.gov (United States)

Wessels, R.L.; Kargel, J.S.; Kieffer, H.H.

2002-01-01

We demonstrate an application of Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) images to detect and monitor supraglacial lakes on glaciers in the Mount Everest region in Tibet (Xizang) and Nepal. ASTER offers powerful capabilities to monitor supraglacial lakes in terms of (1) surface area, growth and disappearance (spatial resolution = 15 m), (2) turbidity (15 m resolution), and (3) temperature (90 m resolution). Preliminary results show an overall similarity of supraglacial lakes on three glaciers. Lakes have widely varying turbidity as indicated by color in visible/near-infrared bands 1-3, the largest lakes being bright blue (highly turbid), cold (near 0??C) and hydrautically connected with other lakes and supraglacial streams, while small lakes are mostly dark blue (relatively clear water), warmer (>4??C), and appear hydrautically isolated. High levels of turbidity in supraglacial lakes indicate high rates of meltwater input from streams or erosion of ice cliffs, and thus are an indirect measure relating to the activity and hydraulic integration of the lake with respect to other lakes and streams in the glacier.

All projects related to chile | IDRC - International Development ...

International Development Research Centre (IDRC) Digital Library (Canada)

Strengthen the use of scientific evidence to inform climate policy, negotiations ... Evaluating the impact of digital tools to teach math and science in Chile ... Business Cooperation and Regional Productive Development in Chile, El Salvador, ...

Sunshine-based estimation of global solar radiation on horizontal surface at Lake Van region (Turkey)

International Nuclear Information System (INIS)

Duzen, Hacer; Aydin, Harun

2012-01-01

Highlights: ► The global solar radiation at Lake Van region is estimated. ► This study is unique for the Lake Van region. ► Solar radiation around Lake Van has the highest value at the east-southeast region. ► The annual average solar energy potential is obtained as 750–2458 kWh/m 2 . ► Results can be used to estimate evaporation. - Abstract: In this study several sunshine-based regression models have been evaluated to estimate monthly average daily global solar radiation on horizontal surface of Lake Van region in the Eastern Anatolia region in Turkey by using data obtained from seven different meteorological stations. These models are derived from Angström–Prescott linear regression model and its derivatives such as quadratic, cubic, logarithmic and exponential. The performance of this regression models were evaluated by comparing the calculated clearness index and the measured clearness index. Several statistical tests were used to control the validation and goodness of the regression models in terms of the coefficient of determination, mean percent error, mean absolute percent error, mean biased error, mean absolute biased error, root mean square error and t-statistic. The results of all the regression models are within acceptable limits according to the statistical tests. However, the best performances are obtained by cubic regression model for Bitlis, Gevaş, Hakkari, Muş stations and by quadratic regression model for Malazgirt, Tatvan and Van stations to predict global solar radiation. The spatial distributions of the monthly average daily global solar radiation around the Lake Van region were obtained with interpolation of calculated solar radiation data that acquired from best fit models of the stations. The annual average solar energy potential for Lake Van region is obtained between 750 kWh/m 2 and 2485 kWh/m 2 with annual average of 1610 kWh/m 2 .

Oil and Gas Emergency Policy: Chile 2012 update

Energy Technology Data Exchange (ETDEWEB)

NONE

2012-09-06

Chile has experienced several serious energy supply incidents over the last decade, including major droughts, a sustained gas supply cut from Argentina (since 2004), and a major earthquake in early 2010 which affected electricity networks and refineries, and caused several black-outs. Due to Chile's unique and sinuous geography - it runs 4 300 kilometres from North to South and only 175 kms from East to West- the country's energy markets are regionally disjointed, particularly as the regional gas and electricity grids are not connected. In the arid North, energy demand is dominated by the mining industry, and operates based on a separate thermal-based Sistema Interconectado Norte Grande (SING) electricity grid. The more densely-populated central region (including Santiago) operates on the more hydro-dependent Sistema Interconectado Central (SIC) electricity grid. The southernmost, hydro-rich regions of the country are not connected to the rest of Chile in terms of electricity and gas. The following report is based on an IEA Emergency Response Assessment carried out in 2010 and 2011 which looked specifically at Chile's capacity to respond to short-term emergencies in oil, gas and electricity.

Oil and Gas Emergency Policy: Chile 2012 update

Energy Technology Data Exchange (ETDEWEB)

NONE

2012-09-06

Chile has experienced several serious energy supply incidents over the last decade, including major droughts, a sustained gas supply cut from Argentina (since 2004), and a major earthquake in early 2010 which affected electricity networks and refineries, and caused several black-outs. Due to Chile's unique and sinuous geography - it runs 4 300 kilometres from North to South and only 175 kms from East to West- the country's energy markets are regionally disjointed, particularly as the regional gas and electricity grids are not connected. In the arid North, energy demand is dominated by the mining industry, and operates based on a separate thermal-based Sistema Interconectado Norte Grande (SING) electricity grid. The more densely-populated central region (including Santiago) operates on the more hydro-dependent Sistema Interconectado Central (SIC) electricity grid. The southernmost, hydro-rich regions of the country are not connected to the rest of Chile in terms of electricity and gas. The following report is based on an IEA Emergency Response Assessment carried out in 2010 and 2011 which looked specifically at Chile's capacity to respond to short-term emergencies in oil, gas and electricity.

Land use impacts on lake water quality in Alytus region (Lithuania)

Science.gov (United States)

Pereira, Paulo; Laukonis, Rymvidas

2016-04-01

Land use has important impacts on soils, surface and ground water quality. Urban agricultural areas are an important source of pollutants, which can reach lakes through surface runoff and underground circulation. Human intervention in the landscape is one of the major causes pollution and land degradation, thus it is very important to understand the impacts of and use on environment and if they have some spatial pattern (Pereira et al., 2013, 2015; Brevik et al., 2016). The identification of the spatial pattern of lakes pollution is in Alytus area (Lithuania) is fundamental, since they provide an important range of ecosystem services to local communities, including food and recreational activities. Thus, the degradation of these environments can induce important economic losses. In this context, it is import to identify the areas with high pollutant accumulation and the environmental and human factors responsible for it. The objective of this work is to study identify the amount of some important nutrients resultant from human activities in lake water quality in Alytus region (Lithuania). Alytus region is located in southern part of Lithuania and has an approximate area of 40 km2. Inside this region we analyzed several water quality parameters of 55 lakes, including, pH, electrical conductivity (EC), suspended materials (SM), water clarity (WC) biochemical oxygen demand (BDO), total phosphorous (TP), total Nitrogen (TN), dissolved organic carbon (DOC), as other environmental variables as altitude, lake maximum deep (MD), lake area and land use according Corine land cover classification (CLC2006). Previous to data analysis, data normality and homogeneity of the variances, was assessed with the Shapiro-wilk and Leven's test, respectively. The majority of the data did not respect the Gaussian distribution and the heteroscedasticity, even after a logarithmic, and box-cox transformation. Thus, in this work we used the logarithmic transformed data to do a principal

Water resources of the Lake Erie shore region in Pennsylvania

Science.gov (United States)

Mangan, John William; Van Tuyl, Donald W.; White, Walter F.

1952-01-01

An abundant supply of water is available to the Lake Erie Shore region in Pennsylvania. Lake i£rie furnishes an almost inexhaustible supply of water of satisfactory chemical quality. Small quantities of water are available from small streams in the area and from the ground. A satisfactory water supply is one of the factors that affect the economic growth of a region. Cities and towns must have adequate amounts of pure water for human consumption. Industries must have suitable water ih sufficient quantities for all purposes. In order to assure. success and economy, the development of water resources should be based on adequate knowledge of the quantity and quality of the water. As a nation, we can not afford to run the risk of dissipating our resources, especially in times of national emergency, by building projects that are not founded on sound engineering and adequate water-resources information. The purpose of this report is to summarize and interpret all available water-resources information for the Lake Erie Shore region in Pennsylvania. The report will be useful for initial guidance in the location or expansion of water facilities for defense and nondefense industries and the municipalities upon which they are dependent. It will also be useful in evaluating the adequacy of the Geological Survey's part of the basic research necessary to plan the orderly development of the water resources of the Lake Erie Shore region. Most of the data contained inthis report have been obtained'by the U. S. Geological Survey in cooperation with the Pennsylvania Department of Forests and Waters, the Pennsylvania Department of Internal Affairs, and the Pennsylvania State Planning Board, Department of Commerce. The Pennsylv~nia Department of Health furnished information on water pollution. The report was prepared in the Water Resources Division of the U. S. Geological Survey b:y John W. Mangan (Surface Water). Donald W. VanTuyl (Ground Water). and Walter F. White, Jr. (Quality of

Geochemistry of thermal/mineral waters in the Clear Lake region, California, and implications for hot dry rock geothermal development

Energy Technology Data Exchange (ETDEWEB)

Goff, F.; Adams, A.I.; Trujillo, P.E.; Counce, D.; Mansfield, J.

1993-02-01

Thermal/mineral waters of the Clear Lake region are broadly classified as thermal meteoric and connote types based on chemical and isotopic criteria. Ratios of conservative components such as B/Cl are extremely different among all thermal/mineral waters of the Clear Lake region except for clusters of waters emerging from specific areas such as the Wilbur Springs district and the Agricultural Park area south of Mt. Konocti. In contrast, ratios of conservative components in large, homogeneous geothermal reservoirs are constant. Stable isotope values of Clear Lake region waters show a mixing trend between thermal meteoric and connote end-members. The latter end-member has enriched [delta]D as well as enriched d[sup l8]O, very different from typical high-temperature geothermal reservoir waters. Tritium data and modeling of ages indicate most Clear Lake region waters are 500 to > 10,000 yr., although mixing of old and young components is implied by the data. The age of end-member connate water is probably > 10,000 yr. Subsurface equilibration temperature of most thermal/mineral waters of the Clear Lake region is [le] 150[degrees]C based on chemical geothermometers but it is recognized that Clear Lake region waters are not typical geothermal fluids and that they violate rules of application of many geothermometers. The combined data indicate that no large geothermal reservoir underlies the Clear Lake region and that small localized reservoirs have equilibration temperatures [le] 150[degrees]C (except for Sulphur Bank Mine). Hot dry rock technologies are the best way to commercially exploit the known high temperatures existing beneath the Clear Lake region, particularly within the main Clear Lake volcanic field.

Regional Analysis of the Hazard Level of Glacial Lakes in the Cordillera Blanca, Peru

Science.gov (United States)

Chisolm, Rachel E.; Jhon Sanchez Leon, Walter; McKinney, Daene C.; Cochachin Rapre, Alejo

2016-04-01

The Cordillera Blanca mountain range is the highest in Peru and contains many of the world's tropical glaciers. This region is severely impacted by climate change causing accelerated glacier retreat. Secondary impacts of climate change on glacier retreat include stress on water resources and the risk of glacial lake outburst floods (GLOFs) from the many lakes that are forming and growing at the base of glaciers. A number of GLOFs originating from lakes in the Cordillera Blanca have occurred over the last century, several of which have had catastrophic impacts on cities and communities downstream. Glaciologists and engineers in Peru have been studying the lakes of the Cordillera Blanca for many years and have identified several lakes that are considered dangerous. However, a systematic analysis of all the lakes in the Cordillera Blanca has never before been attempted. Some methodologies for this type of systematic analysis have been proposed (eg. Emmer and Vilimek 2014; Wang, et al. 2011), but as yet they have only been applied to a few select lakes in the Cordillera Blanca. This study uses remotely sensed data to study all of the lakes of the Glacial Lake Inventory published by the Glaciology and Water Resources Unit of Peru's National Water Authority (UGRH 2011). The objective of this study is to assign a level of potential hazard to each glacial lake in the Cordillera Blanca and to ascertain if any of the lakes beyond those that have already been studied might pose a danger to nearby populations. A number of parameters of analysis, both quantitative and qualitative, have been selected to assess the hazard level of each glacial lake in the Cordillera Blanca using digital elevation models, satellite imagery, and glacier outlines. These parameters are then combined to come up with a preliminary assessment of the hazard level of each lake; the equation weighting each parameter draws on previously published methodologies but is tailored to the regional characteristics

Birth Outcomes across Three Rural-Urban Typologies in the Finger Lakes Region of New York

Science.gov (United States)

Strutz, Kelly L.; Dozier, Ann M.; van Wijngaarden, Edwin; Glantz, J. Christopher

2012-01-01

Purpose: The study is a descriptive, population-based analysis of birth outcomes in the New York State Finger Lakes region designed to determine whether perinatal outcomes differed across 3 rural typologies. Methods: Hospital birth data for the Finger Lakes region from 2006 to 2007 were used to identify births classified as low birthweight (LBW),…

Vivienda social periurbana en Santiago de Chile: la exclusión a escala regional del trasurbanita de Santiago de Chile

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César Cáceres-Seguel

2017-01-01

Full Text Available La localización periurbana de vivienda social en Santiago de Chile ha sido am-pliamente estudiada desde sus implicancias territoriales y políticas, sin embargo,poco sabemos del impacto de estas urbanizaciones en la calidad de vida delhabitante. Mediante entrevistas con residentes de proyectos localizados en Lampase sugiere el surgimiento detrasurbanitas, para ellos, el acceso a un bienestarbásico depende de habitar cotidianamente territorios fragmentados entre lavivienda periurbana y comunas centrales que albergan servicios urbanos elemen-tales. El subsidio de vivienda desencadena la exclusión a escala regional congrupos habitando bordes periurbanos carentes de transporte público eficiente yservicios básicos.

Effects of exotic fish farms on bird communities in lake and marine ecosystems

Science.gov (United States)

Jiménez, Jaime E.; Arriagada, Aldo M.; Fontúrbel, Francisco E.; Camus, Patricio A.; Ávila-Thieme, M. Isidora

2013-08-01

Salmon farming is a widespread activity around the world, also known to promote diverse environmental effects on aquatic ecosystems. However, information regarding the impact of salmon farming on bird assemblages is notably scarce. We hypothesize that salmon farming, by providing food subsidies and physical structures to birds, will change their local community structure. To test this hypothesis, we conducted a seasonal monitoring of bird richness, abundance, and composition at paired salmon pen and control plots in two marine and two lake sites in southern Chile, from fall 2002 to summer 2004. Overall, salmon farming had no significant effects on species richness, but bird abundance was significantly and noticeably higher in salmon pens than in controls. Such aggregation was mainly accounted for by the trophic guilds of omnivores, diving piscivores, carrion eaters, and perching piscivores, but not by invertebrate feeders, herbivores, and surface feeders. Species composition was also significantly and persistently different between salmon pens and controls within each lake or marine locality. The patterns described above remained consistent across environment types and seasons indicating that salmon farming is changing the community structure of birds in both lake and marine habitats by promoting functional and aggregation responses, particularly by favoring species with broader niches. Such local patterns may thus anticipate potential threats from the ongoing expansion of the salmon industry to neighboring areas in Chile, resulting in regional changes of bird communities, toward a less diverse one and dominated by opportunistic, common, and generalist species such as gulls, vultures, and cormorants.

[Gene geography of Chile: regional distribution of American, European and African genetic contributions].

Science.gov (United States)

Fuentes, Macarena; Pulgar, Iván; Gallo, Carla; Bortolini, María-Cátira; Canizales-Quinteros, Samuel; Bedoya, Gabriel; González-José, Rolando; Ruiz-Linares, Andrés; Rothhammer, Francisco

2014-03-01

The geographical distribution of genes plays a key role in genetic epidemiology. The Chilean population has three major stem groups (Native American, European and African). To estimate the regional rate of American, European and African admixture of the Chilean population. Forty single nucleotide polymorphisms (SNP´s) which exhibit substantially different frequencies between Amerindian populations (ancestry-informative markers or AIM´s), were genotyped in a sample of 923 Chilean participants to estimate individual genetic ancestry. The American, European and African individual average admixture estimates for the 15 Chilean Regions were relatively homogeneous and not statistically different. However, higher American components were found in northern and southern Chile and higher European components were found in central Chile. A negative correlation between African admixture and latitude was observed. On the average, American and European genetic contributions were similar and significantly higher than the African contribution. Weighted mean American, European and African genetic contributions of 44.34% ± 3 9%, 51.85% ± 5.44% and 3.81% ± 0.45%, were estimated. Fifty two percent of subjects harbor African genes. Individuals with Aymara and Mapuche surnames have an American admixture of 58.64% and 68.33%, respectively. Half of the Chilean population harbors African genes. Participants with Aymara and Mapuche surnames had a higher American genetic contribution than the general Chilean population. These results confirm the usefulness of surnames as a first approximation to determine genetic ancestry.

The mosses (Bryophyta) of Capitán Prat Province, Aisén Region, southern Chile.

Science.gov (United States)

Larraín, Juan

2016-01-01

The bryophytes of Capitán Prat province have remained one of the least explored in Chile. The eventual construction of several dams on the rivers Baker and Pascua required prospection of all groups of organisms including bryophytes, work that was facilitated by the recent construction of vehicular roads that now offer easy access to previously almost unaccessible locations. The results of intense bryophyte collecting during the austral summer of 2007 are here presented. A total of 260 moss taxa are reported for the province, corresponding to 256 species and four infraspecific taxa, of which 211 are new records for the province, 54 are new for Aisén Region, and two are new records for continental Chile ( Pohlia longicollis (Hedw.) Lindb. and Rigodium toxarion var. robustum (Broth.) Zomlefer). Twelve species extend their known distribution ranges to the north, whereas 49 extend them to the south.

The agropecuarian sector in Los Lagos region, and the paradigm "Chile power food": challenges for a national agrarian policy

Directory of Open Access Journals (Sweden)

Sandra Ríos Núñez

2014-08-01

Full Text Available The restructuring of the economic model in Chile in the mid- seventies hit all productive fields and the agropecuarian sector was no exception. Thus started the beginning of the "Agricultural export Age" that fostered productive guidelines with clear competitive advantages in international markets. The Chilean agricultural paradigm has been characterized by functioning on the basis of low wages, availability of labor and favorable exchange rate. In 2006, under this scenario, the public policy called "Chile Power Food 2020" was implemented, which seeks to reinforce the above formula. This initiative considers growth strategies which make bimodal agrarian structure, present in the country, invisible. To the above an added aggravating factor is that territories (such as Los Lagos Region in southern Chile with traditional productive orientations (specifically cattle have clearly vulnerable positions, especially in those producer groups which are characterized by different rationales to run business

Sustainability Assessment in Development Planning in Sub-National Territories: Regional Development Strategies in Chile

Directory of Open Access Journals (Sweden)

Iván Franchi-Arzola

2018-05-01

Full Text Available In Chile, the increasing occurrence of socio-environmental conflicts demonstrates that Regional Development Strategies—Estrategia Regional de Desarrollo (ERD—as the main development policy of subnational territories (Regions, must consider sustainability as a central objective. The Taxonomy of Sustainability constitutes an assessment method that allows us to determine the correlation between the definitions of these public policies and the strategies for transition to sustainable development. The ERD of the Antofagasta and Aysén regions are the ones presenting the highest Taxonomic Index; this indicates a higher strategic content for the promotion of sustainability. It is also noted that the political will that conditions the principles and values on which the ERD are based is strongly determined by investment projects and socio-environmental conflicts, which represent the tension between environmental protection and the capacity and interests of regional society in the development project.

Variaciones glaciales durante el Holoceno en Patagonia Central, Aisén, Chile: evidencias geomorfológicas Holocene glacial variations in Central Patagonia, Aisén, Chile: geomorphological evidences

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María Mardones

2011-07-01

en la temperatura y precipitación atmosférica.During the Holocene, the patagonian glaciers were characterized by geomorphologically registered advances and retreats. This paper presents the geomorphological evolution and evidences of Holocene glacial advances within a segment in Central Patagonia Cordillera. This area will be used as a reference for studying the postglacial paleoclimatic evolution in the southernmost part of South America. The study area is the río Blanco basin (45°30'S, located in Central Patagonia (Aisén Region, Chile. Radiometric dating of organic sediments, within terminal moraines, provides preliminary data of two glacial advances. The first one is represented by the Lake Elizalde frontal moraine, which yielded a 14C age of 9.370±50 years BP (10,700 to 10,480 cal. yr BP. According to this chronological age, this glacial event took place in the Early Holocene. This glacial advance, being 100 to 200 years older than that observed immediately south of the study area, on the eastern edge of General Carrera Lake (or Buenos Aires Lake, in Argentina and approximately 100 years younger than the event recorded in the Puerto Banderas I moraine (Argentino Lake, 50°S. These results show that the behavior patterns of the Central Patagonia glaciers differ from that observed both in the Lake District (41°S, Chile and in the Magallanes District (54°S, Chile, where there are no traces of glacial readvancement recorded during the Early Holocene. After a major retreat to the west, a more recent glacial advance occurred in the Quetro river valley (a tributary river of the Blanco river, at an age prior to 2.250±40 BP (2.340 to 2.150 cal. yr BP, comparable to the cold stage of the Middle Neoglacial, interpreted to have occurred in different parts of Patagonia. Confronting these results with previously published pollen records, we postulate that the cause of both glacier fluctuations are regional variations in the atmospheric temperature and precipitations.

Register of the last 1000 years of environmental, climatic and anthropogenic change in Isla Grande de Chiloé, inferred through a multi-proxy approach: Lake Pastahué, Chile-South Center (42°S)

Science.gov (United States)

Troncoso, Jose; Alvarez, Denisse; Díaz, Gustavo; Fierro, Pablo; Araneda, Alberto; Torrejón, Fernando; Rondanelli, Mauricio; Fagel, Nathalie; Urrutia, Roberto

2017-04-01

Knowledge of the past environmental and climatic conditions of the lake ecosystems of the Isla Grande de Chiloé and its relationship with the anthropic effect, on a high temporal resolution scale, is scarcely known. Specifically, multi-proxy studies provide a better understanding of the context in which changes occurred in the past. This insular region is particularly interesting because environmental conditions (pre and post-Hispanic) and knowledge about the impacts generated in the ecosystems during the Spanish colonization process have so far been little studied, compared to the rest of Chile continental. This research is a new contribution to the scarce information existing for the last millennium of the Isla Grande de Chiloé. The objective of this work was to reconstruct the environmental and climatic history of the last 1000 years, from the Lake Pastahué, in the Isla Grande de Chiloé through a multi-proxy analysis and compare them with other records for the region. The core sediment was sub-sampled to perform sedimentological analysis (organic matter, carbonates, magnetic susceptibility and granulometry) and biological indicators (pollen, chironomids). The age model was constructed from the activity of 210Pb,137Cs and 14C. The pollen results reveal a composition of nordpatagónico forest represented by Nothofagus, Weinmannia, Drimys, Tepualia, Myrtaceae, Poaceae and Pteridophyta, while the anthropic effect for the last cm of the profile is represented by Rumex and Pinus. The results show a significant increase in magnetic susceptibility since the middle of the 20th century, suggesting an increase in allochthonous material to the lake. The sedimentological parameters and the chironomid assembly show similar variations along the profile, which also shows changes in the trophic state of the lake. The changes recorded in lake Pastahue are directly related to past climatic phenomena occurring in the last millennium, such as the medieval climatic anomaly (MCA

Lake Morphometry for NHD Lakes in California Region 18 HUC

Data.gov (United States)

U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

Lake Morphometry for NHD Lakes in Tennessee Region 6 HUC

Data.gov (United States)

U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

Lake Morphometry for NHD Lakes in Ohio Region 5 HUC

Data.gov (United States)

U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

Characteristics of commuters in Chile: an insight into the future creation of a new region

Directory of Open Access Journals (Sweden)

Gary Concha Murua

2017-06-01

Full Text Available The study analyzes information found in the New National Employment Survey (NENE about the main dimensions and characteristics of inter-regional residence-work mobility in Ñuble, Chile, for the 2014 period. Using an autonomy model of supply and demand, a hypothetical scenario was created that characterizes the future Ñuble region according to its status as a provider or net claimant, incorporating an analysis of the main socio-economic characteristics of the region´s population such as gender, educational level, occupational field and economic activity. It should be highlighted as a main result that more than 80% of commuters are men with a low level of education who work in low-level technical improvement.

Great Lakes O shore Wind Project: Utility and Regional Integration Study

Energy Technology Data Exchange (ETDEWEB)

Sajadi, Amirhossein [Case Western Reserve Univ., Cleveland, OH (United States); Loparo, Kenneth A. [Case Western Reserve Univ., Cleveland, OH (United States); D' Aquila, Robert [General Electric (GE), Albany, NY (United States); Clark, Kara [National Renewable Energy Lab. (NREL), Golden, CO (United States); Waligorski, Joseph G. [FirstEnergy, Akron, OH (United States); Baker, Scott [PJM Interconnection, Audubon, PA (United States)

2016-06-30

This project aims to identify transmission system upgrades needed to facilitate offshore wind projects as well as operational impacts of offshore generation on operation of the regional transmission system in the Great Lakes region. A simulation model of the US Eastern Interconnection was used as the test system as a case study for investigating the impact of the integration of a 1000MW offshore wind farm operating in Lake Erie into FirstEnergy/PJM service territory. The findings of this research provide recommendations on offshore wind integration scenarios, the locations of points of interconnection, wind profile modeling and simulation, and computational methods to quantify performance, along with operating changes and equipment upgrades needed to mitigate system performance issues introduced by an offshore wind project.

Tendencies of ecological changes in the region of Ignalina NPP and in Lake Drukshiai

International Nuclear Information System (INIS)

Pashkauskas, R.; Mazeika, J.; Baubinas, R.

1999-01-01

Since 1979, when the construction of the Ignalina Nuclear Power Plant started, a group of specialists from Lithuania research and academic institutions began to investigate both Lake Drukshiai - the cooler of the Ignalina NPP and the neighbouring area. The investigations were aimed not only at monitoring the environmental consequences of the Ignalina NPP impact but also at forecasting changes of the ecosystems. The State Scientific Program 'Ignalina Nuclear Power Plant and the Environment' was the result of final stage of complex investigations. This conference paper contains data on the changes of thermal state and water balance of Lake Drukshiai, the effect of permanent thermal and chemical pollution on the chemical composition and hydrochemical regime, the pollution of the lake water, the geochemical-contaminated state, the condition, dynamics and the changes of hydrobiont communities in Lake Drukshiai. Radioecological and eco toxicological state of Ignalina NPP region and Lake Drukshiai is estimated as well as changes in Lake Drukshiai and Ignalina NPP surrounding area ecosystems under the combine anthropogenic impact of the plant influence are elucidated. The findings on medical and biological studies in the Ignalina NPP influence population zone and the evidence of impact of Ignalina NPP on social-territorial processes in the region are presented as well

Viabilidad económica de la producción de espárrago en la Región del Maule, Chile Economic viability of asparagus production in the Maule Region, Chile

Directory of Open Access Journals (Sweden)

Germán L Andrade

2006-06-01

Full Text Available En esta investigación se estimaron indicadores de viabilidad y de eficiencia económica de la producción de espárrago (Asparagus officinalis L. en Chile. Los coeficientes técnicos fueron tomados de los registros históricos de un predio localizado en la zona de Linares, Región del Maule, Chile. Los indicadores de viabilidad calculados fueron el valor actual neto (VAN, tasa interna de retorno (TIR, índice de valor actual neto (IVAN, razón beneficio-costo (RBC, y período de recuperación del capital (PRC. Los indicadores de eficiencia económica fueron el costo medio total (CMET, margen unitario ponderado (MUP y la rentabilidad sobre capital (RSC. Como unidad de análisis se consideró una hectárea. Para productores con tierra, los resultados obtenidos en la situación estándar fueron: Ch$1,52 millones (VAN, 12,1% (TIR, 0,3 (IVAN, 1,1 (RBC y 10 años (PRC. Para la etapa de producción se proyectó un CMET mínimo de Ch $317,8 kg-1, un MUP máximo de Ch$407 kg-1 y una RSC de 20,3%. La principal conclusión es que el cultivo de espárrago en la región del Maule, en Chile, es viable para los productores con tierra.Viability and economic efficiency indicators for asparagus (Asparagus officinalis L. production in Chile were evaluated. Technical parameters were obtained from an historical farm located in Linares area, Maule Region, Chile. Viability was assessed by means of net present value (VAN, internal rate of return (TIR, net present value index (IVAN, cost-benefit ratio (RBC, and investment recovery period (PRC. Economic efficiency was assessed through production average cost (CMET, weighted unit margin (MUP, and return on equity (RSC. The analysis was based upon one hectare. Results for producers who own their land were US$ 2,529 ha-1 (VAN, 12.14% (TIR, 0.25 (IVAN, and 1.1 (RBC. The minimum CMET was estimated at US$ 0.53 kg-1 the maximum MUP at US$ 0.68 kg-1, and RSC until 20.3%. The main conclusion is that asparagus production in the

Regional Photonics Initiative at the College of Lake County

Science.gov (United States)

Dulmes, Steven; Kellerhals, William

2017-01-01

The College of Lake County Regional Photonics Initiative project was motivated in part by the hiring of out-of-state technicians for local Photonics industry positions. Fifteen high paying employment opportunities during the recent recession could not be filled from the locally available workforce. Research on the current demand and future growth…

Variability of 14C reservoir age and air-sea flux of CO2 in the Peru-Chile upwelling region during the past 12,000 years

Science.gov (United States)

Carré, Matthieu; Jackson, Donald; Maldonado, Antonio; Chase, Brian M.; Sachs, Julian P.

2016-01-01

The variability of radiocarbon marine reservoir age through time and space limits the accuracy of chronologies in marine paleo-environmental archives. We report here new radiocarbon reservoir ages (ΔR) from the central coast of Chile ( 32°S) for the Holocene period and compare these values to existing reservoir age reconstructions from southern Peru and northern Chile. Late Holocene ΔR values show little variability from central Chile to Peru. Prior to 6000 cal yr BP, however, ΔR values were markedly increased in southern Peru and northern Chile, while similar or slightly lower-than-modern ΔR values were observed in central Chile. This extended dataset suggests that the early Holocene was characterized by a substantial increase in the latitudinal gradient of marine reservoir age between central and northern Chile. This change in the marine reservoir ages indicates that the early Holocene air-sea flux of CO2 could have been up to five times more intense than in the late Holocene in the Peruvian upwelling, while slightly reduced in central Chile. Our results show that oceanic circulation changes in the Humboldt system during the Holocene have substantially modified the air-sea carbon flux in this region.

Innovative potential of small and medium-sized enterprises in the Antofagasta-Chile region: an exploratory study

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Gianni A. Romani Chocce

2006-10-01

Full Text Available The aim of this research is to analyze the innovative potential of Small and Medium Enterprises (SMEs in the Region of Antofagasta - Chile. The paper makes a detailed bibliographic revision on regional innovation processes and presents the results of a questionnaire applied to SMEs, considered as innovative according to the Organization for Economic Co-operation and Development (OCDE criteria. Although these results have to be carefully considered, due to the size of the sample it is possible to observe that there is an increasing awareness of the importance of innovation in the region while, at the same time, many obstacles to innovate are recognized.

Late Holocene vegetation dynamics and lake geochemistry at Laguna Miranda, XI Region, Chile Dinámica vegetaciónal y geoquímica lacustre del Holoceno tardío en Laguna Miranda, XI Región, Chile

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S. G. HABERLE

2000-12-01

Full Text Available Palynological and geochemical analysis of late Holocene lake sediments and dendrochronological analysis of Pilgerodendron in a volcanically active region of southern Chile reveal the long-term impact of a series of tephra fall events and tectonic activity on lake sedimentation and local vegetation. An upper 0,75 m core overlaps with a 4,35 m long Livingstone piston core to give a 4,60 m long sediment record, extending back to 4800 yr BP. Geochemical data shows the shift from allogenic dominance to authigenic and biogenic dominance as waterlogged soils developed within the catchment. This is presumed to have occurred under the influence of continued addition of nutrients to the catchment from tephra deposition and the associated high sedimentation rates. The palynological record from this site is dominated by Nothofagus dombeyi-type and Filicales. The most prominent changes in the pollen record, however, are the gradual decline in Podocarpus nubigena pollen throughout the last 4800 yr; the appearance and increase of Gramineae pollen during the past 2100 yr; and the rapid increase in the pollen of Pilgerodendron uviferum within the past 300-400 yr. Pilgerodendron tree-ring analysis and the pollen results over the last 400 years show that the most recent expansion of Pilgerodendron at the northern and eastern margins of this site is a response to either, periodic tectonic induced watertable changes, or is part of a long-term trend in gymnosperm growth around a shallowing lake margin. The decline of shade-intolerant trees such as Weinmannia and Podocarpus within a Nothofagus-rich forest community towards an increased presence of Pilgerodendron and Gramineae (likely Chusquea bamboo, that began over 2100 yr BP, may have been due as much to autogenic processes such as a change in the disturbance regime resulting in the development of waterlogged soils, rather than to an episode of climate change. It is important to recognise the potential effects of

Vegetation Index, Lake Vegetation Index Regions.This layer describes the spatial extent of the North and South Lake Vegetation Index (LVI) biological regions, as described in Fore et al. 2007, Assessing the Biological Condition of Florida Lakes: Development of the Lake Veg, Published in 2008, 1:24000 (1in=2000ft) scale, Florida Department of Environmental Protection (FDEP).

Data.gov (United States)

NSGIC State | GIS Inventory — Vegetation Index dataset current as of 2008. Lake Vegetation Index Regions.This layer describes the spatial extent of the North and South Lake Vegetation Index (LVI)...

All projects related to Chile | Page 2 | IDRC - International ...

International Development Research Centre (IDRC) Digital Library (Canada)

... living in poverty in the rural-urban territories of Chile, Colombia, and Mexico. ... Region: Brazil, Chile, Colombia, India ... Enhancing Women's Economic Empowerment Through Better Policies in Latin America ... Program: Employment and Growth ... Understanding Think Tank-University Relationships in Latin America.

Air pollution and environmental justice in the Great Lakes region

Science.gov (United States)

Comer, Bryan

While it is true that air quality has steadily improved in the Great Lakes region, air pollution remains at unhealthy concentrations in many areas. Research suggests that vulnerable and susceptible groups in society -- e.g., minorities, the poor, children, and poorly educated -- are often disproportionately impacted by exposure to environmental hazards, including air pollution. This dissertation explores the relationship between exposure to ambient air pollution (interpolated concentrations of fine particulate matter, PM2.5) and sociodemographic factors (race, housing value, housing status, education, age, and population density) at the Census block-group level in the Great Lakes region of the United States. A relatively novel approach to quantitative environmental justice analysis, geographically weighted regression (GWR), is compared with a simplified approach: ordinary least squares (OLS) regression. While OLS creates one global model to describe the relationship between air pollution exposure and sociodemographic factors, GWR creates many local models (one at each Census block group) that account for local variations in this relationship by allowing the value of regression coefficients to vary over space, overcoming OLS's assumption of homogeneity and spatial independence. Results suggest that GWR can elucidate patterns of potential environmental injustices that OLS models may miss. In fact, GWR results show that the relationship between exposure to ambient air pollution and sociodemographic characteristics is non-stationary and can vary geographically and temporally throughout the Great Lakes region. This suggests that regulators may need to address environmental justice issues at the neighborhood level, while understanding that the severity of environmental injustices can change throughout the year.

Utilization of a Marketing Strategy at Naval Regional Medical Center Great Lakes, Great Lakes, Illinois

Science.gov (United States)

1983-06-01

22 Analysis of the Mare.....................22 Development of the Marketing Mix .. .......... 29 A Marketing Mix --Recommendations...problem. Marketing strategy, marketing mix and ultimately the marketing orientation will allow hospitals to persevere and possibly thrive in a somewhat...market are currently being met at Naval Regional Medical Center Great Lakes. The fourth objective is to demonstrate an appropriate marketing mix for

Water Quality and Evaluation of Pesticides in Lakes in the Ridge Citrus Region of Central Florida

Science.gov (United States)

Choquette, Anne F.; Kroening, Sharon E.

2009-01-01

Water chemistry, including major inorganic constituents, nutrients, and pesticide compounds, was compared between seven lakes surrounded by citrus agriculture and an undeveloped lake on the Lake Wales Ridge (herein referred to as the Ridge) in central Florida. The region has been recognized for its vulnerability to the leaching of agricultural chemicals into the subsurface due to factors including soils, climate, and land use. About 40 percent of Florida's citrus cultivation occurs in 'ridge citrus' areas characterized by sandy well drained soils, with the remainder in 'flatwoods citrus' characterized by high water tables and poorly drained soils. The lakes on the Ridge are typically flow-through lakes that exchange water with adjacent and underlying aquifer systems. This study is the first to evaluate the occurrence of pesticides in lakes on the Ridge, and also represents one of the first monitoring efforts nationally to focus on regional-scale assessment of current-use pesticides in small- to moderate-sized lakes (5 to 393 acres). The samples were collected between December 2003 and September 2005. The lakes in citrus areas contained elevated concentrations of major inorganic constituents (including alkalinity, total dissolved solids, calcium, magnesium, sodium, potassium, chloride, and sulfate), total nitrogen, pH, and pesticides compared to the undeveloped lake. Nitrate (as N) and total nitrogen concentrations were typically elevated in the citrus lakes, with maximum values of 4.70 and 5.19 mg/L (milligrams per liter), respectively. Elevated concentrations of potassium, nitrate, and other inorganic constituents in the citrus lakes likely reflect inputs from the surficial ground-water system that originated predominantly from agricultural fertilizers, soil amendments, and inorganic pesticides. A total of 20 pesticide compounds were detected in the lakes, of which 12 compounds exceeded the standardized reporting level of 0.06 ug/L (microgram per liter). Those

NUEVA LOCALIDAD GEOGRAFICA PARA BERBERIS NEGERIANA TISCHLER (BERBERIDACEAE) EN LA PROVINCIA DE ARAUCO, REGION DEL BIO-BIO, CHILE

OpenAIRE

Gómez, Persy; Belov, Michail; San Martín, José

2008-01-01

This note reports the finding of a population of Berberis negeriana Tischler (Berberidaceae), in the province of Arauco, Bío-Bío Region (37°42'17" S y 73°19'43" W) in the center south of Chile. The population was found between Nothofagus obliqua and species of the Valdiviano Forest.

Participación de los gobiernos regionales en la definición de políticas públicas en Chile: el caso del gobierno regional de Los Lagos y la política nacional de acuicultura Participation of regional governments in the definition of public policy in Chile: the case of Los Lagos regional government and the National Policy of Hydroponics

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Alejandro Santibáñez Handschuh

2008-06-01

Full Text Available El artículo aporta evidencia respecto de la participación de los gobiernos regionales en la definición de políticas públicas en Chile a través del caso del gobierno regional de Los Lagos. Se evalúa la participación de los principales actores regionales en la definición de políticas públicas como indicador del grado de centralización en el diseño político institucional en Chile. La metodología utilizada fue el análisis documental relacionado con el caso presentado, el conocimiento del estado del arte respecto del análisis de políticas públicas como disciplina y la descentralización, posteriormente se contrastaron las hipótesis que guiaron el estudio a través del análisis de discurso aplicado a las entrevistas de los actores que estuvieron involucrados en la definición de la Política Nacional de Acuicultura.The article treats the participation of regional governments in the definition of public policy in Chile through the case of Los Lagos Regional Government. It evaluates the participation of the principal regional actors in the definition of public policy as indicators of the degree of centralization in the political institutional design of Chile. The methodology used was the documentary analysis related to the illustrated case, the knowledge of the state refering to the analysis of public policy as a discipline, and the decentralization. Later it was shown the hypotheses that guided the study through the analysis of discourse applied to the interviews of the actors who were involved in the definition of National Policy of Hydroponics.

Limnological characteristics of 56 lakes in the Central Canadian Arctic Treeline Region

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John P. SMOL

2003-02-01

Full Text Available Measured environmental variables from 56 lakes across the Central Canadian Treeline Region exhibited clear limnological differences among subpolar ecozones, reflecting strong latitudinal changes in biome characteristics (e.g. vegetation, permafrost, climate. Principal Components Analysis (PCA clearly separated forested sites from tundra sites based on distinct differences in limnological characteristics. Increases in major ions and related variables (e.g. dissolved inorganic carbon, DIC were higher in boreal forest sites in comparison to arctic tundra sites. The higher values recorded in the boreal forest lakes may be indirectly related to differences in climatic factors in these zones, such as the degree of permafrost development, higher precipitation and runoff, duration of ice-cover on the lakes, and thicker and better soil development. Similar to trends observed in DIC, substantially higher values for dissolved organic carbon (DOC were measured in boreal forest lakes than in arctic tundra lakes. This was likely due to higher amounts of catchment-derived DOC entering the lakes from coniferous leaf litter sources. Relative to arctic tundra lakes, boreal forest lakes had higher nutrient concentrations, particularly total nitrogen (TN, likely due to warmer conditions, a longer growing season, and higher precipitation, which would enhance nutrient cycling and primary productivity. Results suggest that modern aquatic environments at opposite sides of the central Canadian arctic treeline (i.e. boreal forest and arctic tundra exhibit distinct differences in water chemistry and physical conditions. These limnological trends may provide important information on possible future changes with additional warming.

PeRL: A circum-Arctic Permafrost Region Pond and Lake database

Science.gov (United States)

Muster, Sina; Roth, Kurt; Langer, Moritz; Lange, Stephan; Cresto Aleina, Fabio; Bartsch, Annett; Morgenstern, Anne; Grosse, Guido; Jones, Benjamin; Sannel, A.B.K.; Sjoberg, Ylva; Gunther, Frank; Andresen, Christian; Veremeeva, Alexandra; Lindgren, Prajna R.; Bouchard, Frédéric; Lara, Mark J.; Fortier, Daniel; Charbonneau, Simon; Virtanen, Tarmo A.; Hugelius, Gustaf; Palmtag, J.; Siewert, Matthias B.; Riley, William J.; Koven, Charles; Boike, Julia

2017-01-01

Ponds and lakes are abundant in Arctic permafrost lowlands. They play an important role in Arctic wetland ecosystems by regulating carbon, water, and energy fluxes and providing freshwater habitats. However, ponds, i.e., waterbodies with surface areas smaller than 1. 0 × 104 m2, have not been inventoried on global and regional scales. The Permafrost Region Pond and Lake (PeRL) database presents the results of a circum-Arctic effort to map ponds and lakes from modern (2002–2013) high-resolution aerial and satellite imagery with a resolution of 5 m or better. The database also includes historical imagery from 1948 to 1965 with a resolution of 6 m or better. PeRL includes 69 maps covering a wide range of environmental conditions from tundra to boreal regions and from continuous to discontinuous permafrost zones. Waterbody maps are linked to regional permafrost landscape maps which provide information on permafrost extent, ground ice volume, geology, and lithology. This paper describes waterbody classification and accuracy, and presents statistics of waterbody distribution for each site. Maps of permafrost landscapes in Alaska, Canada, and Russia are used to extrapolate waterbody statistics from the site level to regional landscape units. PeRL presents pond and lake estimates for a total area of 1. 4 × 106 km2 across the Arctic, about 17 % of the Arctic lowland ( s.l.) land surface area. PeRL waterbodies with sizes of 1. 0 × 106 m2 down to 1. 0 × 102 m2 contributed up to 21 % to the total water fraction. Waterbody density ranged from 1. 0 × 10 to 9. 4 × 101 km−2. Ponds are the dominant waterbody type by number in all landscapes representing 45–99 % of the total waterbody number. The implementation of PeRL size distributions in land surface models will greatly improve the investigation and projection of surface inundation and carbon fluxes in permafrost lowlands. Waterbody maps, study area

Application of PIXE to the characterization of vitreous dacites from archaeolgical sites in the Atacama region in northern Chile

Energy Technology Data Exchange (ETDEWEB)

Morales, J.R.; Cancino, S. [Departamento de Fisica, Facultad de Ciencias, Universidad de Chile, Las Palmeras 3425, Nunoa, Santiago 1 (Chile); Miranda, P. [Departamento de Fisica, Facultad de Ciencias, Universidad de Chile, Las Palmeras 3425, Nunoa, Santiago 1 (Chile)], E-mail: pjmirand@gmail.com; Dinator, M.I. [Departamento de Fisica, Facultad de Ciencias, Universidad de Chile, Las Palmeras 3425, Nunoa, Santiago 1 (Chile); Seelenfreund, A. [Universidad Academia de Humanismo Cristiano, Condell 343, Providencia, Santiago (Chile)

2007-11-15

Geochemical characterization studies using PIXE were carried out on 21 vitreous dacite artifacts from early formative archaeological sites in the Atacama region, in northern Chile, and on 13 samples taken from two potential volcanic sources located within the region. Performing statistical analyses it was possible to obtain elemental concentration patterns for the archaeological samples of this material and match some of these artifacts with the geological source samples.

Democratic Republic of Congo A Fertile Ground for Instability in the Great Lakes Region States

Science.gov (United States)

2017-06-09

ravaged by a brutal armed conflict. In comparison to the three past presidents, Joseph Kabila has managed to restore political stability and calm to much...DEMOCRATIC REPUBLIC OF CONGO-A FERTILE GROUND FOR INSTABILITY IN THE GREAT LAKES REGION STATES A thesis presented to the Faculty of...From - To) AUG 2016 – JUNE 2017 4. TITLE AND SUBTITLE Democratic Republic of Congo-A Fertile Ground for Instability in the Great Lakes Region

Parasites of the Green-backed Firecrown (Sephanoides sephaniodes in Chile Parásitos del picaflor chico (Sephanoides sephaniodes en Chile

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Daniel González-Acuña

2011-12-01

Full Text Available Gastrointestinal and external parasites from 12 Green-backed Firecrown (Sephanoides sephaniodes were collected between January 2004 and December 2008 from the Biobío Region south-central Chile and Santiago (central Chile. Helminths collected included 1 trematode species (Mosesia sp. and 1 cestode species (Hymenolepis trinidadensis. The mite Proctophyllodes huitzilopchtlii was the only ectoparasite species found. All these parasites represent new records for Chile and the first parasites reported for this host species.Se recolectaron parásitos internos (gastrointestinales y externos de 12 picaflores (Sephanoides sephaniodes entre enero del 2004 y diciembre del 2008, de la región del Biobío en el centro-sur de Chile y en Santiago, en la región central de Chile. Los helmintos recolectados incluyeron 1 especie de trematodo (Mosesia sp. y 1 de cestodo (Hymenolepis trinidadensis. Únicamente se encontró 1 especie de ectoparásito, el ácaro Proctophyllodes huitzilopchtlii. Todos los parásitos mencionados representan nuevos registros para Chile y se registran por primera vez para este hospedero.

Lake Morphometry for NHD Lakes in Upper Colorado Region 14 HUC

Data.gov (United States)

U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

Lake Morphometry for NHD Lakes in North East Region 1 HUC

Data.gov (United States)

U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

Lake Morphometry for NHD Lakes in Lower Colorado Region 15 HUC

Data.gov (United States)

U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

Lake Morphometry for NHD Lakes in Upper Mississippi Region 7 HUC

Data.gov (United States)

U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

Lake Morphometry for NHD Lakes in Rio Grande Region 13 HUC

Data.gov (United States)

U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

Lake Morphometry for NHD Lakes in Pacific Northwest Region 17 HUC

Data.gov (United States)

U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

Lake Morphometry for NHD Lakes in Lower Mississippi Region 8 HUC

Data.gov (United States)

U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

Lake Morphometry for NHD Lakes in Texas-Gulf Region 12 HUC

Data.gov (United States)

U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

Virtual Borders Between Chile and Its Neighbors: Argentina, Peru and Bolivia

Science.gov (United States)

2007-03-30

Estadísticas, “ Inmigrantes en Chile ”, Santiago Census, 2002 20 ...Studies and Research Center, 1998), 13 22 Military Studies and Research Center, Chile en la Region. CESIM. 2001; available from <http...Estatuto de Inversiones Extranjeras en Chile ”, ( Santiago: 1974), Capitulo I,19 35 The International Center for Adjustment of Disputes of Investment

Analysis of Thermal Structure of Arctic Lakes at Local and Regional Scales Using in Situ and Multidate Landsat-8 Data

Science.gov (United States)

Huang, Yan; Liu, Hongxing; Hinkel, Kenneth; Yu, Bailang; Beck, Richard; Wu, Jianping

2017-11-01

The Arctic coastal plain is covered with numerous thermokarst lakes. These lakes are closely linked to climate and environmental change through their heat and water budgets. We examined the intralake thermal structure at the local scale and investigated the water temperature pattern of lakes at the regional scale by utilizing extensive in situ measurements and multidate Landsat-8 remote sensing data. Our analysis indicates that the lake skin temperatures derived from satellite thermal sensors during most of the ice-free summer period effectively represent the lake bulk temperature because the lakes are typically well-mixed and without significant vertical stratification. With the relatively high-resolution Landsat-8 thermal data, we were able to quantitatively examine intralake lateral temperature differences and gradients in relation to geographical location, topography, meteorological factors, and lake morphometry for the first time. Our results suggest that wind speed and direction not only control the vertical stratification but also influences lateral differences and gradients of lake surface temperature. Wind can considerably reduce the intralake temperature gradient. Interestingly, we found that geographical location (latitude, longitude, distance to the ocean) and lake morphometry (surface size, depth, volume) not only control lake temperature regionally but also affect the lateral temperature gradient and homogeneity level within each individual lake. For the Arctic coastal plain, at regional scales, inland and southern lakes tend to have larger horizontal temperature differences and gradients compared to coastal and northern lakes. At local scales, large and shallow lakes tend to have large lateral temperature differences relative to small and deep lakes.

[Early child development inequalities and associated factors between public and private providers at metropolitan region in Chile].

Science.gov (United States)

Bedregal, Paula; Hernández, Viviana; Mingo, M Verónica; Castañón, Carla; Valenzuela, Patricia; Moore, Rosario; de la Cruz, Rolando; Castro, Daniela

Early child development is a population determinant of physical, mental and social health. To know the base line situation prior to the implementation of "Chile grows with you" (Chile Crece Contigo) is key to its evaluation. To compare early child development and associated factors at baseline in pre-school children from public and private health sectors. The sample consisted of 1045 children aged 30-58 months, 52% male, and 671 from the public and 380 from the private sector of the metropolitan region in Chile were evaluated using Battelle Developmental Inventory-1 and a household interview of primary carer. Abnormal child development was found in 14.4% of children in the private sector compared to 30.4% in the public sector. There were no differences in adaptive area (26.3% vs 29.2%), but there were statistically significant differents in cognitive (8.8% vs 12.1%), social-personal (13.2% vs 32.5%), motor (19.2% vs 35.3%), and communication (19% vs 36.8%) development. The logistic regression showed that, independent of socioeconomic level, the risk factors are: Apgarsocial policy. Copyright © 2016 Sociedad Chilena de Pediatría. Publicado por Elsevier España, S.L.U. All rights reserved.

Diversidad de la familia Carabidae (Coleoptera en Chile Diversity of the family Carabidae (Coleoptera in Chile

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SERGIO ROIG-JUÑENT

2001-09-01

that of the Neotropics and other South American countries. There are 21 tribes of Carabidae represented in Chile (38.8 % of the total found in Neotropics, with 95 genera (28.2 % of the Neotropical fauna, and 365 species (7.9 % of the total from the Neotropics. Chile has a low number of tribes compared with other countries, but it is an important area because six relictual tribes occur within it, being mostly gondwanan or pangeic. At the generic level, 18 genera are endemic (18.5 % of Chilean genera, 28 genera are restricted to Chile and Argentina, and six to Chile, Argentina, and Uruguay. The number of carabid species in Chile is low compared with other South American countries, but the number of endemic species is high, 204, which is 55.8 % of the total carabid fauna of the country. This high endemicity in Chile might be due to Chile´s isolated situation in South America. The Andean mountains and the Northern Desert region, separate Chile from most of the neotropical fauna, as is shown by the absence of important tribes such as the Galeritini, Scaritini, and Brachinini. Keys for all genera present in Chile are provided, with a brief description of habitat and species richness of each

Adapting to climate variability and change in Chile's Maipo basin ...

International Development Research Centre (IDRC) Digital Library (Canada)

2014-04-09

Apr 9, 2014 ... Given the region's role in Chile's national economy, a strategy for adapting to ... to Chile's economy, and may be threatened by future water stress. ... for the project, with the goal of bringing together government, business, and ...

Cold Lake-Beaver River water management study update: Report of the Cold Lake Regional Water Management Task Force

International Nuclear Information System (INIS)

1994-01-01

The Cold Lake Regional Water Management Task Force was formed in 1992, comprising representatives from local governments, aboriginal groups, the oil industry, and the public. The Task Force's mandate was to advise Alberta Environmental Protection on updating the Cold Lake-Beaver River Water Management Plan, taking into acocunt the views and concerns of the public, industry, and local governments. Industrial water use was found to be the key issue to be addressed in the plan update, so the Task Force focused on reviewing industrial water supply options and developing recommendations on the appropriate water supply to meet long-term requirements. A subcommittee was established to monitor groundwater use by the heavy oil industry. This committee took readings at Imperial Oil's water production and observation wells on a biweekly basis. Nine options for supplying industrial water requirements were examined and evaluated using criteria including supply reliability, economic factors, and impacts on other users and the environment. The Task Force found that the preferred source of water for industrial use is the North Saskatchewan River, to be accessed by a water pipeline. The second and less desirable source of water for industrial use would be a system of weirs on Cold or Primrose Lakes and Wolf Lake, supplemented by the use of brackish water to the maximum extent possible. In the interim, industry was recommended to maximize its use of brackish water and continue to use surface and ground water within existing license limits. Other recommendations were to form provincial or regional boards to oversee water use and issue water licenses, to treat water as a resource, and to establish a fee for industrial use of water. 3 figs., 5 tabs

Delineating the Drainage Structure and Sources of Groundwater Flux for Lake Basaka, Central Rift Valley Region of Ethiopia

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Megersa Olumana Dinka

2017-11-01

Full Text Available As opposed to most of the other closed basin type rift valley lakes in Ethiopia, Lake Basaka is found to be expanding at an alarming rate. Different studies indicated that the expansion of the lake is challenging the socio-economics and environment of the region significantly. This study result and previous reports indicated that the lake’s expansion is mostly due to the increased groundwater (GW flux to the lake. GW flux accounts for about 56% of the total inflow in recent periods (post 2000 and is found to be the dominant factor for the hydrodynamics and existence of the lake. The analysis of the drainage network for the area indicates the existence of a huge recharge area on the western and upstream side of the catchment. This catchment has no surface outlet; hence most of the incoming surface runoff recharges the GW system. The recharge area is the main source of GW flux to the lake. In addition to this, the likely sources/causes of GW flux to the lake could be: (i an increase of GW recharge following the establishment of irrigation schemes in the region; (ii subsurface inflow from far away due to rift system influence, and (iii lake neotectonism. Overall, the lake’s expansion has damaging effect to the region, owing to its poor water quality; hence the identification of the real causes of GW flux and mitigation measures are very important for sustainable lake management. Therefore a comprehensive and detailed investigation of the parameters related to GW flux and the interaction of the lake with the GW system of the area is highly recommended.

Spatial and Temporal Trends of Snowfall in Central New York - A Lake Effect Dominated Region

Science.gov (United States)

Hartnett, Justin Joseph

Central New York is located in one of the snowiest regions in the United States, with the city of Syracuse, New York the snowiest metropolis in the nation. Snowfall in the region generally begins in mid-November and lasts until late-March. Snow accumulation occurs from a multitude of conditions: frontal systems, mid-latitude cyclones, Nor'easters, and most notably lake-effect storms. Lake effect snowfall (LES) is a difficult parameter to forecast due to the isolated and highly variable nature of the storm. Consequently, studies have attempted to determine changes in snowfall for lake-effect dominated regions. Annual snowfall patterns are of particular concern as seasonal snowfall totals are vital for water resources, winter businesses, agriculture, government and state agencies, and much more. Through the use of snowfall, temperature, precipitation, and location data from the National Weather Service's Cooperative Observer Program (COOP), spatial and temporal changes in snowfall for Central New York were determined. In order to determine climatic changes in snowfall, statistical analyses were performed (i.e. least squares estimation, correlations, principal component analyses, etc.) and spatial maps analyzed. Once snowfall trends were determined, factors influencing the trends were examined. Long-term snowfall trends for CNY were positive for original stations (˜0.46 +/- 0.20 in. yr -1) and homogenously filtered stations (0.23 +/- 0.20 in. yr -1). However, snowfall trends for shorter time-increments within the long-term period were not consistent, as positive, negative, and neutral trends were calculated. Regional differences in snowfall trends were observed for CNY as typical lake-effect areas (northern counties, the Tug Hill Plateau and the Southern Hills) experienced larger snowfall trends than areas less dominated by LES. Typical lake-effect months (December - February) experienced the greatest snowfall trend in CNY compared to other winter months. The

The influence of climate change to European Lakes, with a special emphasis in the Balkan Region

International Nuclear Information System (INIS)

Kuusisto, Esko

2004-01-01

There are almost one and half million lakes in Europe, if small water bodies with an area down to 0.001 km 2 are included. The total area of lakes is over 200.000 km 2 , in addition the man-made reservoirs cover almost 100.000 km 2 . The largest lakes are located in the zone extending from southwestern Sweden through Finland to Russia, but there are many important lakes also in central and southern Europe. The Balkan countries have altogether about ten thousand lakes with a total area of over 4000 km 2 and total volume of almost loo km 3 . Over half of the total volume is in Lake Ohrid, which ranks the seventh in Europe both as to the volume and as to the maximum depth. However, there are around thirty lakes in Europe with their surface area larger than that of Lake Ohrid. In addition to the lakes, the Balkan countries also have thousands of reservoirs with a total water storage capacity of over 50 km 3 . The response of European lakes to climate change can be discussed by dividing the lakes into five categories: 1) deep temperate lakes, 2) shallow temperate lakes, 3) mountain lakes, 4) boreal lakes and 5) arctic lakes. The lakes in the Balkan region fall belong into the first three categories. Most of the deep temperate lakes are warm monomictic; convective overturn occurs in winter or early spring. The future climate change may suppress this overturn, giving these lakes the classification of oligomictic. This implies the enhancement of anoxic bottom conditions and an increased risk of eutrophication. The oxygen conditions can also be expected to deteriorate due to increased bacterial activity in deep waters and superficial bottom sediment. In shallow temperate lakes, higher water temperatures in the future will induce intensified primary production and bacterial decomposition. The probability of harmful extreme events, e.g. the mass production of algae, will increase. The impacts may extend to fishing and recreational use. In lakes with relatively long water

Quantitative Development and Distribution of Zooplankton in Medium Lakes of the Kostanay Region (North Kazakhstan Region)

Science.gov (United States)

Aubakirova, Gulzhan A.; Syzdykov, Kuanysh N.; Kurzhykayev, Zhumagazy; Uskenov, Rashit B.; Narbayev, Serik; Begenova, Ainagul B.; Zhumakayeva, Aikumys N.; Sabdinova, Dinara K.; Akhmedinov, Serikbay N.

2016-01-01

The assessment of water resources plays an important environmental and economic role, since it allows developing an effective program of regional development with regard to the environmental load. The hydro-chemical regime of lakes includes water temperature, content of biogenic elements, total mineralization, oxygen regime, and other parameters…

Progress in study of Prespa Lake using nuclear and related techniques (IAEA Regional Project RER/8/008)

International Nuclear Information System (INIS)

Anovski, Todor

2001-09-01

One of the main objective of the IAEA - Regional project RER/8/008 entitled Study of Prespa Lake Using Nuclear and Related Techniques was to provide a scientific basis for sustainable and environmental management of the Lake Prespa (Three lakes: Ohrid, Big Prespa and Small Prespa are on the borders between Albania, Republic of Macedonia and Greece, and are separated by the Mali i Thate and Galichica, mostly Carstificated mountains), see Fig. 1. In this sense investigations connected with the hydrogeology, water quality (Physics-chemical, biological and radiological characteristics) and water balance determination by application of Environmental isotopes ( i.e. H,D,T,O-18,O-18 etc.,) distribution, artificial water tracers and other relevant analytical techniques such as: AAS, HPLC, Total α and β-activity, α and γ-spectrometry as well as ultra sonic measurements (defining of the Lake bottom profile) through regional cooperation / Scientists from Albania, Greece and Republic of Macedonia, participated in the implementation of the Project/ during one hydrological year, had been initiated and valuable results obtained, a part of which are presented in this report. This cooperation was the only way for providing necessary data for better understanding beside the other, of the water quality of the Prespa Lake and its hydrological relationship to Ohrid Lake too, representing a unique regional hydro system in the world. (Author)

Latencia y banco de semillas en plantas de la región mediterránea de Chile central Seed bank and dormancy in plants of the Mediterranean region of central Chile

Directory of Open Access Journals (Sweden)

JAVIER A. FIGUEROA

2004-03-01

Full Text Available Los bancos de semillas en las regiones mediterráneas presentan rasgos particulares que los distinguen de bancos de otras regiones del mundo. El banco de semillas es concentración de propágulos viables enterrados en el suelo por períodos variables de tiempo. Los bancos de semillas del matorral de Chile central son principalmente transitorios y funcionalmente semejantes a los bancos presentes en otros ecosistemas mediterráneos no perturbados por fuego, a excepción de Australia. El banco transitorio es aquel formado por semillas que permanecen viables en los horizontes superiores del suelo por no más de 1 año después de la dispersión. En el matorral de Chile central, en los horizontes superiores del suelo, se encuentra una de las densidades de semillas de hierbas más altas de las regiones mediterráneas. Una gran proporción de esta reserva está constituida por semillas sin latencia, fácilmente germinables, especialmente pastos anuales que germinan en otoño. Con respecto a los mecanismos de latencia de las semillas del banco transitorio responsables del almacenamiento de las semillas en el suelo, nuestra revisión bibliográfica reveló los siguientes principales síndromes de germinación: (1 especies con semillas que deben ser estratificadas en frío debido a la presencia de latencia fisiológica (principalmente hierbas introducidas; (2 especies con semillas que deben ser escarificadas con ácidos o procedimientos mecánicos debido a la presencia de latencia física (principalmente especies leñosas nativas; (3 especies con latencia fisiológica que necesitan de estratificación cálida para activar la germinación (hierbas nativas e introducidas. Estos síndromes provocan que la época de germinación en Chile central esté situada entre otoño e inicio de la primavera. Además, no hay referencias sobre la presencia de algún síndrome esporádico de germinación para los componentes de un banco de semillas permanente. Proponemos

Scale and watershed features determine lake chemistry patterns across physiographic regions in the far north of Ontario, Canada

Directory of Open Access Journals (Sweden)

Josef MacLeod

2016-11-01

Full Text Available Changes in the far north of Ontario (>50°N latitude, like climate warming and increased industrial development, will have direct effects on watershed characteristics and lakes. To better understand the nature of remote northern lakes that span the Canadian Shield and Hudson Bay Lowlands, and to address the pressing need for limnological data for this vast, little-studied area of Ontario, lake chemistry surveys were conducted during 2011-2012. Lakes at the transition between these physiographic regions displayed highly variable water chemistry, reflecting the peatland landscape with a mix of bog and fen watersheds, and variations in the extent of permafrost. In the transition area, Shield and Lowlands lakes could not be clearly differentiated based on water chemistry; peat cover decouples, to varying degrees, the lakes from the influences of bedrock and surficial deposits. Regional chemistry differences were apparent across a much broader area of northern Ontario, due to large-scale spatial changes in geology and in the extent of peatlands and permafrost.  Shield lakes in the far northwest of Ontario had Ca, Mg, and TP concentrations markedly higher than those of many Lowlands lakes and previously studied Shield lakes south of 50°N, related to an abundance of lacustrine and glacial end-moraine deposits in the north.

Expanded spatial extent of the Medieval Climate Anomaly revealed in lake-sediment records across the boreal region in northwest Ontario.

Science.gov (United States)

Laird, Kathleen R; Haig, Heather A; Ma, Susan; Kingsbury, Melanie V; Brown, Thomas A; Lewis, C F Michael; Oglesby, Robert J; Cumming, Brian F

2012-09-01

Multi-decadal to centennial-scale shifts in effective moisture over the past two millennia are inferred from sedimentary records from six lakes spanning a ~250 km region in northwest Ontario. This is the first regional application of a technique developed to reconstruct drought from drainage lakes (open lakes with surface outlets). This regional network of proxy drought records is based on individual within-lake calibration models developed using diatom assemblages collected from surface sediments across a water-depth gradient. Analysis of diatom assemblages from sediment cores collected close to the near-shore ecological boundary between benthic and planktonic diatom taxa indicated this boundary shifted over time in all lakes. These shifts are largely dependent on climate-driven influences, and can provide a sensitive record of past drought. Our lake-sediment records indicate two periods of synchronous signals, suggesting a common large-scale climate forcing. The first is a period of prolonged aridity during the Medieval Climate Anomaly (MCA, c. 900-1400 CE). Documentation of aridity across this region expands the known spatial extent of the MCA megadrought into a region that historically has not experienced extreme droughts such as those in central and western north America. The second synchronous period is the recent signal of the past ~100 years, which indicates a change to higher effective moisture that may be related to anthropogenic forcing on climate. This approach has the potential to fill regional gaps, where many previous paleo-lake depth methods (based on deeper centrally located cores) were relatively insensitive. By filling regional gaps, a better understanding of past spatial patterns in drought can be used to assess the sensitivity and realism of climate model projections of future climate change. This type of data is especially important for validating high spatial resolution, regional climate models. © 2012 Blackwell Publishing Ltd.

Imagining the Great Lakes Region: discourses and practices of civil society regional approaches for peacebuilding in Rwanda, Burundi and DR Congo

NARCIS (Netherlands)

Leeuwen, van M.

2008-01-01

The idea has gained ground in recent years that, as conflicts in the countries of the Great Lakes Region are strongly interlinked, regional approaches are necessary to resolve them. This interest in regional dimensions of conflict and peacebuilding also gains currency in other parts of the world.

Great Lakes

Science.gov (United States)

Edsall, Thomas A.; Mac, Michael J.; Opler, Paul A.; Puckett Haecker, Catherine E.; Doran, Peter D.

1998-01-01

The Great Lakes region, as defined here, includes the Great Lakes and their drainage basins in Minnesota, Wisconsin, Illinois, Indiana, Ohio, Pennsylvania, and New York. The region also includes the portions of Minnesota, Wisconsin, and the 21 northernmost counties of Illinois that lie in the Mississippi River drainage basin, outside the floodplain of the river. The region spans about 9º of latitude and 20º of longitude and lies roughly halfway between the equator and the North Pole in a lowland corridor that extends from the Gulf of Mexico to the Arctic Ocean.The Great Lakes are the most prominent natural feature of the region (Fig. 1). They have a combined surface area of about 245,000 square kilometers and are among the largest, deepest lakes in the world. They are the largest single aggregation of fresh water on the planet (excluding the polar ice caps) and are the only glacial feature on Earth visible from the surface of the moon (The Nature Conservancy 1994a).The Great Lakes moderate the region’s climate, which presently ranges from subarctic in the north to humid continental warm in the south (Fig. 2), reflecting the movement of major weather masses from the north and south (U.S. Department of the Interior 1970; Eichenlaub 1979). The lakes act as heat sinks in summer and heat sources in winter and are major reservoirs that help humidify much of the region. They also create local precipitation belts in areas where air masses are pushed across the lakes by prevailing winds, pick up moisture from the lake surface, and then drop that moisture over land on the other side of the lake. The mean annual frost-free period—a general measure of the growing-season length for plants and some cold-blooded animals—varies from 60 days at higher elevations in the north to 160 days in lakeshore areas in the south. The climate influences the general distribution of wild plants and animals in the region and also influences the activities and distribution of the human

Helminths of Milvago chimango temucoensis (Aves: Falconiformes from Los Ríos Region, Chile: New Records for Neotropical Raptors

Directory of Open Access Journals (Sweden)

Oyarzún-Ruiz P.

2016-12-01

Full Text Available The goal of the present survey was to improve the scarce knowledge regard the endoparasites of raptors in Chile and South America. Thus, necropsy was performed on 14 chimango caracara Milvago chimango temucoensis from Los Ríos Region, Chile. From all examined birds, 78.6% were positive to helminths. The species identified were Capillaria tenuissima, Pterothominx sp., Baruscapillaria falconis, Cosmocephalus obvelatus, Skrjabinoclava sp., Synhimantus (Dispharynx nasuta, Synhimantus (D. sp., Synhimantus (Synhimantus sp., Paracuaria adunca, Procyrnea spinosa, Porrocaecum depressum, Contracaecum rudolphii sensu lato, Stephanoprora sp. and Polymorphus mutabilis. All species listed, with the exception of C. tenuissima, P. spinosa and P. depressum, are new records for the chimango caracara. Furthermore C. obvelatus, Skrjabinoclava sp., S. (D. nasuta, S. (D. sp., P. adunca, C. rudolphii s. l., Stephanoprora sp. and P. mutabilis all are new records for Neotropical raptors.

The 1985 central chile earthquake: a repeat of previous great earthquakes in the region?

Science.gov (United States)

Comte, D; Eisenberg, A; Lorca, E; Pardo, M; Ponce, L; Saragoni, R; Singh, S K; Suárez, G

1986-07-25

A great earthquake (surface-wave magnitude, 7.8) occurred along the coast of central Chile on 3 March 1985, causing heavy damage to coastal towns. Intense foreshock activity near the epicenter of the main shock occurred for 11 days before the earthquake. The aftershocks of the 1985 earthquake define a rupture area of 170 by 110 square kilometers. The earthquake was forecast on the basis of the nearly constant repeat time (83 +/- 9 years) of great earthquakes in this region. An analysis of previous earthquakes suggests that the rupture lengths of great shocks in the region vary by a factor of about 3. The nearly constant repeat time and variable rupture lengths cannot be reconciled with time- or slip-predictable models of earthquake recurrence. The great earthquakes in the region seem to involve a variable rupture mode and yet, for unknown reasons, remain periodic. Historical data suggest that the region south of the 1985 rupture zone should now be considered a gap of high seismic potential that may rupture in a great earthquake in the next few tens of years.

Reconstruction of Late Pleistocene Paleoenvironments using bulk geochemistry of paleosols from the Lake Victoria Region

Science.gov (United States)

Beverly, Emily J.; Peppe, Daniel J.; Driese, Steven G.; Blegen, Nick; Faith, J. Tyler; Tryon, Christian A.; Stinchcomb, Gary E.

2017-11-01

The impact of changing environments on the evolution and dispersal of Homo sapiens is highly debated, but few data are available from equatorial Africa. Lake Victoria is the largest freshwater lake in the tropics and is currently a biogeographic barrier between the eastern and western branches of the East African Rift. The lake has previously desiccated at 17 ka and again at 15 ka, but little is known from this region prior to the Last Glacial Maximum. The Pleistocene terrestrial deposits on the northeast coast of Lake Victoria (94 to 36 ka) are ideal for paleoenvironmental reconstructions where volcaniclastic deposits (tuffs), fluvial deposits, tufa, and paleosols are exposed, which can be used to reconstruct Critical Zones (CZ) of the past (paleo-CZs). The paleo-CZ is a holistic concept that reconstructs the entire landscape using geologic records of the atmosphere, hydrosphere, lithosphere, biosphere, and pedosphere (the focus of this study). New paleosol-based mean annual precipitation (MAP) proxies from Karungu, Rusinga Island, and Mfangano Island indicate an average MAP of 750108 mm yr-1 (CALMAG), 800182 mm yr-1 (CIA-K), and 1010228 mm yr-1 (PPM1.0) with no statistical difference throughout the 11 m thick sequence. This corresponds to between 54 and 72% of modern precipitation. Tephras bracketing these paleosols have been correlated across seven sites, and sample a regional paleo-CZ across a 55 km transect along the eastern shoreline of the modern lake. Given the sensitivity of Lake Victoria to precipitation, it is likely that the lake was significantly smaller than modern between 94 ka and 36 ka. This would have removed a major barrier for the movement of fauna (including early modern humans) and provided a dispersal corridor across the equator and between the rifts. It is also consistent with the associated fossil faunal assemblage indicative of semi-arid grasslands. During the Late Pleistocene, the combined geologic and paleontological evidence suggests a

Reconstruction of Late Pleistocene Paleoenvironments Using Bulk Geochemistry of Paleosols from the Lake Victoria Region

Directory of Open Access Journals (Sweden)

Emily J. Beverly

2017-11-01

Full Text Available The impact of changing environments on the evolution and dispersal of Homo sapiens is highly debated, but few data are available from equatorial Africa. Lake Victoria is the largest freshwater lake in the tropics and is currently a biogeographic barrier between the eastern and western branches of the East African Rift. The lake has previously desiccated at ~17 ka and again at ~15 ka, but little is known from this region prior to the Last Glacial Maximum. The Pleistocene terrestrial deposits on the northeast coast of Lake Victoria (94–36 ka are ideal for paleoenvironmental reconstructions where volcaniclastic deposits (tuffs, fluvial deposits, tufa, and paleosols are exposed, which can be used to reconstruct Critical Zones (CZ of the past (paleo-CZs. The paleo-CZ is a holistic concept that reconstructs the entire landscape using geologic records of the atmosphere, hydrosphere, lithosphere, biosphere, and pedosphere (the focus of this study. New paleosol-based mean annual precipitation (MAP proxies from Karungu, Rusinga Island, and Mfangano Island indicate an average MAP of 750 ± 108 mm year−1 (CALMAG, 800 ± 182 mm year−1 (CIA-K, and 1,010 ± 228 mm year−1 (PPM1.0 with no statistical difference throughout the 11 m thick sequence. This corresponds to between 54 and 72% of modern precipitation. Tephras bracketing these paleosols have been correlated across seven sites, and sample a regional paleo-CZ across a ~55 km transect along the eastern shoreline of the modern lake. Given the sensitivity of Lake Victoria to precipitation, it is likely that the lake was significantly smaller than modern between 94 and 36 ka. This would have removed a major barrier for the movement of fauna (including early modern humans and provided a dispersal corridor across the equator and between the rifts. It is also consistent with the associated fossil faunal assemblage indicative of semi-arid grasslands. During the Late Pleistocene, the combined geologic and

Spatial distribution and source apportionment of PFASs in surface sediments from five lake regions, China.

Science.gov (United States)

Qi, Yanjie; Huo, Shouliang; Xi, Beidou; Hu, Shibin; Zhang, Jingtian; He, Zhuoshi

2016-03-07

Perfluoroalkyl substances (PFASs) have been found in environment globally. However, studies on PFAS occurrence in sediments of lakes or reservoirs remain relatively scarce. In this study, two hundred and sixty-two surface sediment samples were collected from forty-eight lakes and two reservoirs all over China. Average PFAS concentrations in surface sediments from each lake or reservoir varied from 0.086 ng/g dw to 5.79 ng/g dw with an average of 1.15 ng/g dw. Among five lake regions, average PFAS concentrations for the lakes from Eastern Plain Region were the highest. Perfluorooctanoic acid, perfluoroundecanoic acid and perfluorooctane sulfonic acid (PFOS) were the predominant PFASs in surface sediments. The significant positive correlations between PFAS concentrations and total organic carbon, total nitrogen and total phosphorus contents in sediments revealed the influences of sedimentary characteristics on PFAS occurrence. A two-dimensional hierarchical cluster analysis heat map was depicted to analyze the possible origins of sediments and individual PFAS. The food-packaging, textile, electroplating, firefighting and semiconductor industry emission sources and the precious metals and coating industry emission sources were identified as the main sources by two receptor models, with contributions of 77.7 and 22.3% to the total concentrations of C4-C14- perfluoroalkyl carboxylic acids and PFOS, respectively.

Lake Morphometry for NHD Lakes in Souris Red Rainy Region 9 HUC

Data.gov (United States)

U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

Lake Morphometry for NHD Lakes in Arkansas White Red Region 11 HUC

Data.gov (United States)

U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

[Fertility Survey, Metropolitana region, Chile 1989].

Science.gov (United States)

1990-01-01

A fertility study was carried out by the Chilean Association for Protection of the Family (APROFA) in metropolitan Chile in 1989 to update data from the most recent fertility study in 1974. A random and self-weighted sample of 600 women aged 15-44 in 32 urban communes of the metropolitan region were interviewed in November 1989. 55% were married or in stable consensual unions, 39.1% were single, and 5.9% were separated, divorced, or widowed. 24.1% had primary educations, 15.5% had some form of higher education, and .2% were illiterate. 64.2% of the women had children, of whom 63.8% had 1 or 2. Only 2.1% had 6 or more children. 46.2% felt that the ideal family size was 1-2 children and 30.7% that it was 3 children. 40.4% of women with children wanted another child and 59.6% did not. 25.1% of the sample had never had sexual relations, 7.3% had not had sexual relations in the 12 months prior to the interview, and the remaining 67.6% were sexually active. At the time of the survey 6.1% were pregnant and 11.1% had had a birth in the preceding 12 months. 28.3% of these pregnancies were considered unwanted, usually for economic reasons or because the family was considered complete. 55.6% of the sample reported using contraceptives. 48.6% used IUDs, 26.0% used oral contraceptives, 6.9% periodic abstinence methods, and 1.8% barrier methods. Only 7.5% of women aged 15-19 used contraception. Rates of use stabilized after age 25 at about 72%. 80.9% of women married or in union used a method, as did 20.2% of single and 59.3% of separated or divorced women. The data for the survey are still under analysis and all statistics are provisional.

ANALYSIS OF MERCURY IN VERMONT AND NEW HAMPSHIRE LAKES: EVALUATION OF THE REGIONAL MERCURY CYCLING MODEL

Science.gov (United States)

An evaluation of the Regional Mercury Cycling Model (R-MCM, a steady-state fate and transport model used to simulate mercury concentrations in lakes) is presented based on its application to a series of 91 lakes in Vermont and New Hampshire. Visual and statistical analyses are pr...

Mapping lake level changes using ICESat/GLAS satellite laser altimetry data: a case study in arid regions of central Asia

Science.gov (United States)

Li, JunLi; Fang, Hui; Yang, Liao

2011-12-01

Lakes in arid regions of Central Asia act as essential components of regional water cycles, providing sparse but valuable water resource for the fragile ecological environments and human lives. Lakes in Central Asia are sensitive to climate change and human activities, and great changes have been found since 1960s. Mapping and monitoring these inland lakes would improve our understanding of mechanism of lake dynamics and climatic impacts. ICESat/GLAS satellite laser altimetry provides an efficient tool of continuously measuring lake levels in these poorly surveyed remote areas. An automated mapping scheme of lake level changes is developed based on GLAS altimetry products, and the spatial and temporal characteristics of 9 typical lakes in Central Asia are analyzed to validate the level accuracies. The results show that ICESat/GLAS has a good performance of lake level monitoring, whose patterns of level changes are the same as those of field observation, and the max differences between GLAS and field data is 3cm. Based on the results, it is obvious that alpine lakes are increasing greatly in lake levels during 2003-2009 due to climate change, while open lakes with dams and plain endorheic lakes decrease dramatically in water levels due to human activities, which reveals the overexploitation of water resource in Central Asia.

Coupling of microbial nitrogen transformations and climate in sclerophyll forest soils from the Mediterranean Region of central Chile.

Science.gov (United States)

Pérez, Cecilia A; Armesto, Juan J

2018-06-01

The Mediterranean region of central Chile is experiencing extensive "mega-droughts" with detrimental effects for the environment and economy of the region. In the northern hemisphere, nitrogen (N) limitation of Mediterranean ecosystems has been explained by the decoupling between N inputs and plant uptake during the dormant season. In central Chile, soils have often been considered N-rich in comparison to other Mediterranean ecosystems of the world, yet the impacts of expected intensification of seasonal drought remain unknown. In this work, we seek to disentangle patterns of microbial N transformations and their seasonal coupling with climate in the Chilean sclerophyll forest-type. We aim to assess how water limitation affects microbial N transformations, thus addressing the impact of ongoing regional climate trends on soil N status. We studied four stands of the sclerophyll forest-type in Chile. Field measurements in surface soils showed a 67% decline of free-living diazotrophic activity (DA) and 59% decrease of net N mineralization rates during the summer rainless and dormant season, accompanied by a stimulation of in-situ denitrification rates to values 70% higher than in wetter winter. Higher rates of both free-living DA and net N mineralization found during spring, provided evidence for strong coupling of these two processes during the growing season. Overall, the experimental addition of water in the field to litter samples almost doubled DA but had no effect on denitrification rates. We conclude that coupling of microbial mediated soil N transformations during the wetter growing season explains the N enrichment of sclerophyll forest soils. Expected increases in the length and intensity of the dry period, according to climate change models, reflected in the current mega-droughts may drastically reduce biological N fixation and net N mineralization, increasing at the same time denitrification rates, thereby potentially reducing long-term soil N capital

Environmental status of the Lake Michigan region. Volume 3. Chemistry of Lake Michigan

Energy Technology Data Exchange (ETDEWEB)

Torrey, M S

1976-05-01

The report is a synoptic review of data collected over the past twenty years on the chemistry of Lake Michigan. Changes in water quality and sediment chemistry, attributable to cultural and natural influences, are considered in relation to interacting processes and factors controlling the distribution and concentration of chemical substances within the Lake. Temperature, light, and mixing processes are among the important natural influences that affect nutrient cycling, dispersal of pollutants, and fate of materials entering the Lake. Characterization of inshore-offshore and longitudinal differences in chemical concentrations and sediment chemistry for the main body of the Lake is supplemented by discussion of specific areas such as Green Bay and Grand Traverse Bay. Residues, specific conductance, dissolved oxygen, major and trace nutrients, and contaminants are described in the following context: biological essentiality and/or toxicity, sources to the Lake, concentrations in the water column and sediments, chemical forms, seasonal variations and variation with depth. A summary of existing water quality standards, statutes, and criteria applicable to Lake Michigan is appended.

Controls on the geochemical evolution of Prairie Pothole Region lakes and wetlands over decadal time scales

Science.gov (United States)

Goldhaber, Martin B.; Mills, Christopher T.; Mushet, David M.; McCleskey, R. Blaine; Rover, Jennifer

2016-01-01

One hundred sixty-seven Prairie Pothole lakes, ponds and wetlands (largely lakes) previously analyzed chemically during the late 1960’s and early to mid-1970’s were resampled and reanalyzed in 2011–2012. The two sampling periods differed climatically. The earlier sampling took place during normal to slightly dry conditions, whereas the latter occurred during and immediately following exceptionally wet conditions. As reported previously in Mushet et al. (2015), the dominant effect was expansion of the area of these lakes and dilution of their major ions. However, within that context, there were significant differences in the evolutionary pathways of major ions. To establish these pathways, we employed the inverse modeling computer code NetpathXL. This code takes the initial and final lake composition and, using mass balance constrained by the composition of diluting waters, and input and output of phases, calculates plausible geochemical evolution pathways. Despite the fact that in most cases major ions decreased, a subset of the lakes had an increase in SO42−. This distinction is significant because SO42− is the dominant anion in a majority of Prairie Pothole Region wetlands and lakes. For lakes with decreasing SO42−, the proportion of original lake water required for mass balance was subordinate to rainwater and/or overland flow. In contrast, lakes with increasing SO42− between the two sampling episodes tended to be dominated by original lake water. This suite of lakes tended to be smaller and have lower initial SO42−concentrations such that inputs of sulfur from dissolution of the minerals gypsum or pyrite had a significant impact on the final sulfur concentration given the lower dilution factors. Thus, our study provides context for how Prairie Pothole Region water bodies evolve geochemically as climate changes. Because wetland geochemistry in turn controls the ecology of these water bodies, this research contributes to the prediction of the

Results of photochemical modeling sensitivity analyses in the Lake Michigan region: Current status of Lake Michigan Ozone Control Program (LMOP) modeling

Energy Technology Data Exchange (ETDEWEB)

Dolwick, P.D. [Lake Michigan Air Directors Consortium, Des Plaines, IL (United States); Kaleel, R.J. [Illinois Environmental Protection Agency, Springfield, IL (United States); Majewski, M.A. [Wisconsin Dept. of Natural Resources, Madison, WI (United States)

1994-12-31

The four states that border Lake Michigan are cooperatively applying a state-of-the-art nested photochemical grid model to assess the effects of potential emission control strategies on reducing elevated tropospheric ozone concentrations in the region to levels below the national ambient air quality standard. In order to provide an extensive database to support the application of the photochemical model, a substantial data collection effort known as the Lake Michigan Ozone Study (LMOS) was completed during the summer of 1991. The Lake Michigan Ozone Control Program (LMOP) was established by the States of Illinois, Wisconsin, Michigan, and Indiana to carry out the application of the modeling system developed from the LMOS, in terms of developing the attainment demonstrations required from this area by the Clean Air Act Amendments of 1990.

Behavioral problems and tobacco use among adolescents in Chile

Directory of Open Access Journals (Sweden)

Caris Luis

2003-01-01

Full Text Available OBJECTIVE: To examine the association between behavioral problems and tobacco smoking among adolescent students in Chile. METHODS: Data were drawn from a study that included questionnaire surveys of 46 907 school-attending adolescents in all 13 of the administrative regions of Chile. Assessments were based on an adapted, Spanish-language version of the Drug Use Screening Inventory. The conditional form of the logistic regression model was used for analysis, with matching of students on individual schools, and with further statistical adjustments for sex, age, and selected risk factors. RESULTS: The prevalence of tobacco smoking among the adolescents was very high across all of Chile, with a level between 56% and 65% in each of the 13 regions. The estimated odds of tobacco use in youths at the highest level of behavioral problems was about twice that for youths at the lowest levels, both before and after controlling for sex, age, lack of participation in recreational activities, level of irritability, and levels of problems with school, family attention, and mental health. CONCLUSIONS: These findings help to complement and complete the evidence of prior studies on tobacco smoking among adolescents with behavior problems, including recent research on Central American youths. Although the magnitude of observed associations in Chile was not as great as that for the associations found in Central America, both the strength of these associations and their statistical significance were observed throughout Chile. This is the first study in Chile on potentially causal relationships such as these.

Ecology of playa lakes

Science.gov (United States)

Haukos, David A.; Smith, Loren M.

1992-01-01

Between 25,000 and 30,000 playa lakes are in the playa lakes region of the southern high plains (Fig. 1). Most playas are in west Texas (about 20,000), and fewer, in New Mexico, Oklahoma, Kansas, and Colorado. The playa lakes region is one of the most intensively cultivated areas of North America. Dominant crops range from cotton in southern areas to cereal grains in the north. Therefore, most of the native short-grass prairie is gone, replaced by crops and, recently, grasses of the Conservation Reserve Program. Playas are the predominant wetlands and major wildlife habitat of the region.More than 115 bird species, including 20 species of waterfowl, and 10 mammal species have been documented in playas. Waterfowl nest in the area, producing up to 250,000 ducklings in wetter years. Dominant breeding and nesting species are mallards and blue-winged teals. During the very protracted breeding season, birds hatch from April through August. Several million shorebirds and waterfowl migrate through the area each spring and fall. More than 400,000 sandhill cranes migrate through and winter in the region, concentrating primarily on the larger saline lakes in the southern portion of the playa lakes region.The primary importance of the playa lakes region to waterfowl is as a wintering area. Wintering waterfowl populations in the playa lakes region range from 1 to 3 million birds, depending on fall precipitation patterns that determine the number of flooded playas. The most common wintering ducks are mallards, northern pintails, green-winged teals, and American wigeons. About 500,000 Canada geese and 100,000 lesser snow geese winter in the playa lakes region, and numbers of geese have increased annually since the early 1980’s. This chapter describes the physiography and ecology of playa lakes and their attributes that benefit waterfowl.

REGISTER OF NESTS OF THREE FORMICID SPECIES (HYMENOPTERA) IN RÍO CLARILLO NATIONAL RESERVE, METROPOLITAN REGION, CHILE

OpenAIRE

Ipinza-Regla, Joaquín; Jara, Pamela; Araya, Jaime E.

2017-01-01

ABSTRACT The distribution of formicids Brachymyrmex giardii (Emery), Camponotus chilensis (Spinola), and Nothidris bicolor (Snelling) was registered with the minimum area method in two sectors of Río Clarillo National Reserve (33° 41-51' S and 70° 24-29' W), Pirque Commune, Metropolitan Region, Chile. One sector corresponded to an area with human presence, while the other corresponded to an area with less human intervention. The nests presented a group distribution, and the presence of people...

Spatial distribution and source apportionment of PFASs in surface sediments from five lake regions, China

Science.gov (United States)

Qi, Yanjie; Huo, Shouliang; Xi, Beidou; Hu, Shibin; Zhang, Jingtian; He, Zhuoshi

2016-03-01

Perfluoroalkyl substances (PFASs) have been found in environment globally. However, studies on PFAS occurrence in sediments of lakes or reservoirs remain relatively scarce. In this study, two hundred and sixty-two surface sediment samples were collected from forty-eight lakes and two reservoirs all over China. Average PFAS concentrations in surface sediments from each lake or reservoir varied from 0.086 ng/g dw to 5.79 ng/g dw with an average of 1.15 ng/g dw. Among five lake regions, average PFAS concentrations for the lakes from Eastern Plain Region were the highest. Perfluorooctanoic acid, perfluoroundecanoic acid and perfluorooctane sulfonic acid (PFOS) were the predominant PFASs in surface sediments. The significant positive correlations between PFAS concentrations and total organic carbon, total nitrogen and total phosphorus contents in sediments revealed the influences of sedimentary characteristics on PFAS occurrence. A two-dimensional hierarchical cluster analysis heat map was depicted to analyze the possible origins of sediments and individual PFAS. The food-packaging, textile, electroplating, firefighting and semiconductor industry emission sources and the precious metals and coating industry emission sources were identified as the main sources by two receptor models, with contributions of 77.7 and 22.3% to the total concentrations of C4-C14- perfluoroalkyl carboxylic acids and PFOS, respectively.

Regional Climate Models as a Tool for Assessing Changes in the Laurentian Great Lakes Net Basin Supply

Science.gov (United States)

Music, B.; Mailhot, E.; Nadeau, D.; Irambona, C.; Frigon, A.

2017-12-01

Over the last decades, there has been growing concern about the effects of climate change on the Great Lakes water supply. Most of the modelling studies focusing on the Laurentian Great Lakes do not allow two-way exchanges of water and energy between the atmosphere and the underlying surface, and therefore do not account for important feedback mechanisms. Moreover, energy budget constraint at the land surface is not usually taken into account. To address this issue, several recent climate change studies used high resolution Regional Climate Models (RCMs) for evaluating changes in the hydrological regime of the Great Lakes. As RCMs operate on the concept of water and energy conservation, an internal consistency of the simulated energy and water budget components is assured. In this study we explore several recently generated Regional Climate Model (RCM) simulations to investigate the Great Lakes' Net Basin Supply (NBS) in a changing climate. These include simulations of the Canadian Regional Climate Model (CRCM5) supplemented by simulations from several others RCMs participating to the North American CORDEX project (CORDEX-NA). The analysis focuses on the NBS extreme values under nonstationary conditions. The results are expected to provide useful information to the industries in the Great Lakes that all need to include accurate climate change information in their long-term strategy plans to better anticipate impacts of low and/or high water levels.

Checklist, diversity and distribution of testate amoebae in Chile.

Science.gov (United States)

Fernández, Leonardo D; Lara, Enrique; Mitchell, Edward A D

2015-10-01

Bringing together more than 170 years of data, this study represents the first attempt to construct a species checklist and analyze the diversity and distribution of testate amoebae in Chile, a country that encompasses the southwestern region of South America, countless islands and part of the Antarctic. In Chile, known diversity includes 416 testate amoeba taxa (64 genera, 352 infrageneric taxa), 24 of which are here reported for the first time. Species-accumulation plots show that in Chile, the number of testate amoeba species reported has been continually increasing since the mid-19th century without leveling off. Testate amoebae have been recorded in 37 different habitats, though they are more diverse in peatlands and rainforest soils. Only 11% of species are widespread in continental Chile, while the remaining 89% of the species exhibit medium or short latitudinal distribution ranges. Also, species composition of insular Chile and the Chilean Antarctic territory is a depauperated subset of that found in continental Chile. Nearly, the 10% of the species reported here are endemic to Chile and many of them are distributed only within the so-called Chilean biodiversity hotspot (ca. 25° S-47° S). These findings are here thoroughly discussed in a biogeographical and evolutionary context. Copyright © 2015 Elsevier GmbH. All rights reserved.

Lake Area Changes and Their Influence on Factors in Arid and Semi-Arid Regions along the Silk Road

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Chao Tan

2018-04-01

Full Text Available In the context of global warming, the changes in major lakes and their responses to the influence factors in arid and semi-arid regions along the Silk Road are especially important for the sustainable development of local water resources. In this study, the areas of 24 lakes were extracted using MODIS NDVI data, and their spatial-temporal characteristics were analyzed. In addition, the relationship between lake areas and the influence factors, including air temperature, precipitation, evapotranspiration, land use and land cover change (LULCC and population density in the watersheds, were investigated. The results indicated that the areas of most lakes shrank, and the total area decreased by 22,189.7 km2 from 2001 to 2016, except for those of the lakes located on the Qinghai-Tibetan Plateau. The air temperature was the most important factor for all the lakes and increased at a rate of 0.113 °C/a during the past 16 years. LULCC and the increasing population density markedly influenced the lakes located in the middle to western parts of this study area. Therefore, our results connecting lake area changes in the study region highlight the great challenge of water resources and the urgency of implementation of the green policy in the One Belt and One Road Initiative through international collaboration.

The magnetic properties of the Lake Bolshoe Yarovoe (Altai Region, Russia) sediments

Science.gov (United States)

Kosareva, Lina; Nourgaliev, Danis; Nurgalieva, Nuriia; Shcherbakov, Valeriy; Kuzina, Diliara; Antonenko, Vadim; Akhmerov, Rinaz; Evtugyn, Vladimir; Vorob'ev, Vyacheslav

2017-04-01

Magnetic minerals of modern lake sediments provide unique source of information for climate changes, regionally and globally as environmental variations are recorded by them with high resolution. Here we report results of magnetic analysis of the endorheic bitter-salty lake Bolshoe Yarovoe located in the Altai Region, Russia. The lake is the deepest one in the Kulunda Steppe with the average depth 4 m and with the catchment area about 560 km2. Five cores were drileld during field research conducted by the Institute of Geology and Petroleum Technologies (Kazan Federal University, Russia) in 2008. Average length of cores is 4 m. The samples were studied using radiocarbon dating, magnetic susceptibility, NRM measurements, coercivity spectrometry, thermomagnetic analysis, TEM and SEM microscopy. The main components of the sediments magnetization, their variability, defined features of sedimentation processes, also the contribution of the paramagnetic, ferromagnetic, superparamagnetic components are identified. Data variability of the paramagnetic component revealed that the lower part of the section is characterized by a gradual increase in revenues of the clay material. The presence of erosion was detected around of 7500 years ago marking occurrence of a fall of the lake level during this period. After this the flow of clay particles was steady with small fluctuations only, indicating the stabilization of sedimentation processes. Ferromagnetic fraction is mainly represented by magnitofossils of different forms, sizes and grain preservation. Such changes may be related to many factors, such as climate, nutrient availability, and environmental variability. Possible relationships between magnitofossil morphology, their magnetic signal and the depositional environment changes are proposed. The work was carried out according to the Russian Government's Program of Competitive Growth of Kazan Federal University.

Preliminary measurements of tritium, deuterium and oxygen-18 in lakes and groundwater of volcanic Rotorua region, New Zealand

International Nuclear Information System (INIS)

Taylor, C.B.; Freestone, H.J.; Nairn, I.A.

1977-06-01

This report presents an initial survey of the isotopic characteristics of non-hydrothermal waters of Rotorua region. Measurements of deuterium, oxygen and tritium have been made on samples collected between 1970 and 1973. Some major springs emerging close to land-locked lakes have been identified as containing mixtures of lake-derived water and precipitation-derived recharge in the catchments between lake and spring. The stable isotope composition of precipitation-recharged groundwater occupies a fairly narrow range, but is nevertheless seperable into two distinct isotopic families. The circumstances leading to these isotopic differences are not yet fully understood. This isotopic data has been gathered with a view to identifying hydrological problems in the region capable of study by isotopic methods and as essential background data to studies of the region's many hydrothermal systems. (auth.)

The regional and global significance of nitrogen removal in lakes and reservoirs

Science.gov (United States)

Harrison, J.A.; Maranger, R.J.; Alexander, Richard B.; Giblin, A.E.; Jacinthe, P.-A.; Mayorga, Emilio; Seitzinger, S.P.; Sobota, D.J.; Wollheim, W.M.

2009-01-01

Human activities have greatly increased the transport of biologically available nitrogen (N) through watersheds to potentially sensitive coastal ecosystems. Lentic water bodies (lakes and reservoirs) have the potential to act as important sinks for this reactive N as it is transported across the landscape because they offer ideal conditions for N burial in sediments or permanent loss via denitrification. However, the patterns and controls on lentic N removal have not been explored in great detail at large regional to global scales. In this paper we describe, evaluate, and apply a new, spatially explicit, annual-scale, global model of lentic N removal called NiRReLa (Nitrogen Retention in Reservoirs and Lakes). The NiRReLa model incorporates small lakes and reservoirs than have been included in previous global analyses, and also allows for separate treatment and analysis of reservoirs and natural lakes. Model runs for the mid-1990s indicate that lentic systems are indeed important sinks for N and are conservatively estimated to remove 19.7 Tg N year-1 from watersheds globally. Small lakes (<50 km2) were critical in the analysis, retaining almost half (9.3 Tg N year -1) of the global total. In model runs, capacity of lakes and reservoirs to remove watershed N varied substantially at the half-degree scale (0-100%) both as a function of climate and the density of lentic systems. Although reservoirs occupy just 6% of the global lentic surface area, we estimate they retain ~33% of the total N removed by lentic systems, due to a combination of higher drainage ratios (catchment surface area:lake or reservoir surface area), higher apparent settling velocities for N, and greater average N loading rates in reservoirs than in lakes. Finally, a sensitivity analysis of NiRReLa suggests that, on-average, N removal within lentic systems will respond more strongly to changes in land use and N loading than to changes in climate at the global scale. ?? 2008 Springer Science

Regional distribution and relevance in paleonvironmental studies of lakes in the Tatra Mts. (Western Carpathians

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Joanna POCIASK-KARTECZKA

2014-11-01

Full Text Available Scientific limnological research in the Tatra Mountains were initiated by Stanislaw Staszic in the early XIX century.  After the World War II, the evolution of Tatra lakes was investigated by Kondracki, Klimaszewski, Baumgart-Kotarba and. Extensive paleolimnological investigations in the Tatra Mountains were started by the group of scientists led by K. Starmach in the beginning of the second half of the 20th century. There has been not much research concerned to the regional distribution of lakes and their properties in the Tatra Mountains (Pociask-Karteczka 2013. Very early division of lakes presented A. Gadomski (1922, which distinguished four types of lakes: a tarns (cirque lake or corrie loch, b bedrock-dammed lakes, c moraine lakes. This division was concerned in subsequent publications (Choiński 2007. M. Lukniš (1973, 1985 recognized additional types: kettles and landslide-dammed lakes and M. Klimaszewski (1988 – inter-sheepback lakes. J. Pacl and K. Wit-Jóźwik in Klima Tatier (Pacl, Wit-Jóźwik 1974 were focused on the temperature of water in lakes in Polish and Slovak parts and M. Borowiak (2000a,b provided a comprehensive analysis of types, dimensions, temperature and chemical composition of water in lakes in the Tatra Mountains.According to present day state of knowledge, one may distinguish following genetic types of lakes: I glacial, II not-glacial. There are four types of the glacial origin lakes in the Tatra Mountains (Fig. 1: a tarns (cirque lakes or corrie loch, b bedrock-moraine dammed lakes, c inter-sheepback lakes, d moraine lakes, e kettles.Most of lakes in the Tatra Mountains are tarns and bedrock-moraine dammed lakes, and they are located at the elevation over 1400 m a.s.l. in the Western Tatra Mountains, and over 1600 m a.s.l. in the High Tatra Mountains. Some of them are paternoster lakes – a series of stair-stepped lakes formed in individual rock basins aligned down the course of a glaciated valley. Lakes in

[Food satisfaction in Mapuche persons in the Metropolitan Region of Santiago, Chile].

Science.gov (United States)

Schnettler, Berta; Miranda, Horacio; Sepúlveda, José; Denegri, Marianela; Mora, Marcos; Lobos, Germán

2011-06-01

Although the study and measurement of satisfaction with life has generated great interest in the last 15 years, there are few works which address satisfaction with food-related life. In order to identify variables which have an influence on satisfaction with food-related life among Mapuche persons, a survey was applied to 400 Mapuche subjects in the Santiago Metropolitan Region, Chile. The scales evaluated in the questionnaire included: SWFL (Satisfaction with Food-related Life), lifestyles, food, and Mapuche acculturation. It was found that 41.0% were extremely satisfied, 40.5% satisfied, 17.2% somewhat satisfied and 1.2% dissatisfied with their food-related life. To identify variables which have an influence on satisfaction with food, an ordinal multinomial logit model was proposed, which was significant (p Mapuche foods, is aged 55 or more, consumes red meat in moderation, consumes foods without additives, try to balance work and private life, does not read the labels of products, and if he/she had Mapuche friends at school. Thus satisfaction with food-related life in Mapuche persons in the Metropolitan Region is related to demographic variables, expenditure on food, consumption of Mapuche foods and life-style.

Lake Afdera: a threatened saline lake in Ethiopia | Getahun | SINET ...

African Journals Online (AJOL)

Lake Afdera is a saline lake located in the Afar region, Northern Ethiopia. Because of its inaccessibility it is one of the least studied lakes of the country. It supports life including three species of fish of which two are endemic. Recently, reports are coming out that this lake is used for salt extraction. This paper gives some ...

Biogenic volatile organic compounds from the urban forest of the Metropolitan Region, Chile

International Nuclear Information System (INIS)

Préndez, Margarita; Carvajal, Virginia; Corada, Karina; Morales, Johanna; Alarcón, Francis; Peralta, Hugo

2013-01-01

Tropospheric ozone is a secondary pollutant whose primary sources are volatile organic compounds and nitrogen oxides. The national standard is exceeded on a third of summer days in some areas of the Chilean Metropolitan Region (MR). This study reports normalized springtime experimental emissions factors (EF) for biogenic volatile organic compounds from tree species corresponding to approximately 31% of urban trees in the MR. A Photochemical Ozone Creation Index (POCI) was calculated using Photochemical Ozone Creation Potential of quantified terpenes. Ten species, natives and exotics, were analysed using static enclosure technique. Terpene quantification was performed using GC-FID, thermal desorption, cryogenic concentration and automatic injection. Observed EF and POCI values for terpenes from exotic species were 78 times greater than native values; within the same family, exotic EF and POCI values were 28 and 26 times greater than natives. These results support reforestation with native species for improved urban pollution management. -- First experimental determination of the emission factors of biogenic volatile organic compounds in the urban forest of the Metropolitan Region, Chile

Protection of Existing and Potential Astronomical Sites in Chile - an Update.

Science.gov (United States)

Smith, M. G.; Sanhueza, P.; Norman, D.; Schwarz, H.; Orellana, D.

2002-12-01

The IAU's Working Group on Controlling Light Pollution (iauwg) has declared Mauna Kea and a wide strip of Northern Chile between Antofagasta and Chajnanator as top priorities for its efforts to protect existing and potential sites in the Northern and Southern hemispheres respectively. This report provides an update on the iauwg's co-ordinated efforts to protect areas around the major international optical observatories in Chile, as well as the "Chilean Special Zone" (CSZ) mentioned above. This zone is of current and potential interest for the installation of extremely large optical telescopes and includes the ALMA radio-astronomy site. The CSZ is potentially vulnerable to adverse effects of mining in the region. Progess has been made in demonstrating to local mining interests within the CSZ the economic advantages of quality lighting. Educational and outreach activities to a variety of target audiences are building on legislation covering dark skies - itself part of work by the Chilean government to protect the natural heritage of Chile. Substantial good will was generated by an international, bilingual conference held last March in Chile. Just in the region around AURA's Observatory in Chile (Gemini South, CTIO and SOAR), a portable planetarium has been used to reach out to over 600 teachers and 65,000 pupils in the RedLaSer schools network within the last three years. This has attracted the direct interest of Chile's Ministry of Education. Videoconferencing over Internet2 is being used for educational purposes between Chile and various sites in the US. The NSF- initiated Mamalluca municipal observatory now receives more visitors than all the international observatories in Chile combined and is the focus of an expanding local industry of astronomical eco-tourism. Most of this work was supported by funding from, or via, the US NSF through CTIO and Gemini, and from ESO, OCIW, CONAMA and the IDA.

Latest Miocene-Pliocene Tiliviche Paleolake, Atacama Desert, Northern Chile 19.5°S: Paleoclimatic and Paleohydrologic Implications

Science.gov (United States)

Kirk-Lawlor, N. E.; Jordan, T. E.; Rech, J.; Lehmann, S.

2010-12-01

Endorheic paleolake deposits of diatomite, mudstone, sandstone, and evaporites are exposed in the Atacama Desert of northern Chile. This study focuses on a major latest Miocene-Pliocene paleolake system centered at 19.5°S, near Tiliviche. A diatiomite unit, up to 35m thick, composed of 0.2-1.5m thick beds of massive, white diatiomite, free of plant matter and root traces, is interpreted have formed from lacustrine diatom blooms. At its maximum extent, the lake would have had a surface area of roughly 200 km2, based on the extent of the diatomite unit, and might have been 50-100 m deep, as inferred by the relationship between the diatomite unit and modern topography. The Tiliviche paleolake initially formed before 6.4 Ma, and much of its sedimentary record formed under a wetter climatic and hydrologic regime than the present. Prior to 3.5 Ma, the lake had evolved into a groundwater-fed saltpan. Polygonally fractured efflorescent halite evaporite and bedded gypsum and gypsarenite evaporite deposits that overlie the diatomite unit are evidence of this saltpan environment. The modern Atacama Desert is hyperarid, with an average precipitation of 2 mm/yr in the driest areas. The paleosol record demonstrates that hyperarid conditions dominated this region since the middle Miocene, albeit with multiple fluctuations to less arid conditions of short to moderately long duration. This hyperaridity is due to the desert’s latitude, ocean currents and the rainshadow created by the Andes. There is no evidence that the rainshadow effect has diminished since the late Miocene, hence global climate changes affecting ocean temperatures and atmospheric patterns likely caused the wetter periods in the Atacama. In particular, prior workers noted wetter conditions in the region ~6-5 Ma, followed by a return to hyper-arid conditions. The regional Pliocene return to hyperaridity coincided with the desiccation of the Tiliviche endorheic lake system. During the late Miocene (~6-5 Ma) wetter

Assessment of biomass cogeneration in the Great Lakes region

International Nuclear Information System (INIS)

Burnham, M.; Easterly, J.L.

1994-01-01

Many biomass cogeneration facilities have successfully entered into power sales agreements with utilities across the country, often after overcoming various difficulties or barriers. Under a project sponsored by the Great Lakes Regional Biomass Energy Program of the U.S. Department of Energy, DynCorp sm-bullet Meridian has conducted a survey of biomass facilities in the seven Great Lakes states, selecting 10 facilities for case studies with at least one facility in each of the seven states. The purpose of the case studies was to address obstacles that biomass processors face in adding power production to their process heat systems, and to provide examples of successful strategies for entering into power sales agreements with utilities. The case studies showed that the primary incentives for investing in cogeneration and power sales are to reduce operating costs through improved biomass waste management and lower energy expenditures. Common barriers to cogeneration and power sales were high utility stand-by charges for unplanned outages and low utility avoided cost payments due to excess utility generation capacity

SEROPREVALENCE OF NINE LEPTOSPIRA INTERROGANS SEROVARS IN WILD CARNIVORES, UNGULATES, AND PRIMATES FROM A ZOO POPULATION IN A METROPOLITAN REGION OF CHILE.

Science.gov (United States)

Moreno-Beas, Eduardo; Abalos, Pedro; Hidalgo-Hermoso, Ezequiel

2015-12-01

Serum samples from 130 individuals representing 42 species of carnivores, ungulates, and primates from a population of captive mammals in Metropolitan Region in Chile were tested for antibodies against nine serovars of Leptospira interrogans using the microscopic agglutination test. Ten percent of the animals were seropositive to one or more serovars. Seroprevalence was significantly higher in ungulates (20.4%) compared to carnivores (3.8%) and primates (3.4%). There were no significant differences in seroprevalence among sex and age ranges. The most frequent serovar detected was Autumnalis, present in 53.4% of antibody-positive animals. Most positive animals had titers of ≤1 : 200, except for a maned wolf ( Chrysocyon brachyurus ) with titers of 1 : 400 against serovar Hardjo. To the authors' knowledge, this is the first report of Leptospira exposure detected in native endangered pudu ( Pudu puda ) and the first confirmation of exposure to L. interrogans in captive wild mammals in Chile. Leptospirosis should be considered as a differential diagnosis in future disease presentation for hepatitis or abortions in captive mammals in Chile.

Local to regional scale industrial heavy metal pollution recorded in sediments of large freshwater lakes in central Europe (lakes Geneva and Lucerne) over the last centuries

International Nuclear Information System (INIS)

Thevenon, Florian; Graham, Neil D.; Chiaradia, Massimo; Arpagaus, Philippe; Wildi, Walter; Poté, John

2011-01-01

This research first focuses on the spatial and temporal patterns of heavy metals from contrasting environments (highly polluted to deepwater sites) of Lake Geneva. The mercury (Hg) and lead (Pb) records from two deepwater sites show that the heavy metal variations before the industrial period are primarily linked to natural weathering input of trace elements. By opposition, the discharge of industrial treated wastewaters into Vidy Bay of Lake Geneva during the second part of the 20th century, involved the sedimentation of highly metal-contaminated sediments in the area surrounding the WWTP outlet pipe discharge. Eventually, a new Pb isotope record of sediments from Lake Lucerne identifies the long-term increasing anthropogenic lead pollution after ca. 1500, probably due to the development of metallurgical activities during the High Middle Ages. These data furthermore allows to compare the recent anthropogenic sources of water pollution from three of the largest freshwater lakes of Western Europe (lakes Geneva, Lucerne, and Constance). High increases in Pb and Hg highlight the regional impact of industrial pollution after ca. 1750–1850, and the decrease of metal pollution in the 1980s due to the effects of remediation strategies such as the implementation of wastewater treatment plants (WWTPs). However, at all the studied sites, the recent metal concentrations remain higher than pre-industrial levels. Moreover, the local scale pollution data reveal two highly contaminated sites (> 100 μg Pb/g dry weight sediment) by industrial activities, during the late-19th and early-20th centuries (Lake Lucerne) and during the second part of the 20th century (Vidy Bay of Lake Geneva). Overall, the regional scale pollution history inferred from the three large and deep perialpine lakes points out at the pollution of water systems by heavy metals during the last two centuries due to the discharge of industrial effluents. Highlights: ► Natural sources dominated trace element

The regional abundance and size distribution of lakes and reservoirs in the United States and implication for estimates of global lake extent

Science.gov (United States)

McDonald, Cory P.; Rover, Jennifer; Stets, Edward G.; Striegl, Robert G.

2012-01-01

We analyzed complete geospatial data for the 3.5 million lakes and reservoirs larger than 0.001 km2, with a combined surface area of 131,000 km2, in the contiguous United States (excluding the Laurentian Great Lakes) and identified their regional distribution characteristics. For Alaska, we also analyzed (1) incomplete data that suggest that the state contains 1–2.5 million lakes larger than 0.001 km2 covering over 50,000 km2 and (2) localized high-resolution (5 m) data that suggest that the number of very small water bodies ( 0.001 km2 in some areas. The Pareto distribution cannot accurately describe the lake abundance-size relationship across the entire size spectrum, and extrapolation of this density function to small size classes has likely resulted in the overestimation of the number of small lakes in the world. While small water bodies dominate in terms of numbers, they are not numerous enough to dominate in terms of surface area, as has been previously suggested. Extending our results to the global scale suggests that there are on the order of 64 million water bodies larger than 0.001 km2 in the world, with a total surface area of approximately 3.8 million km2.

The 24 July 2008 outburst flood at the western Zyndan glacier lake and recent regional changes in glacier lakes of the Teskey Ala-Too range, Tien Shan, Kyrgyzstan

Directory of Open Access Journals (Sweden)

C. Narama

2010-04-01

Full Text Available On 24 July 2008, a glacier lake outburst flood (GLOF occurred at the western (w- Zyndan glacier lake in the Tong District of Ysyk-Köl Oblast, Kyrgyzstan. The flood killed three people and numerous livestock, destroyed infrastructure, and devastated potato and barley crops as well as pastures. Tuurasuu village and a downstream reservoir on the Zyndan river escaped heavy damage because the main flood was diverted toward the Tong river. RTK-GPS and satellite data (Landsat 7 ETM+, ALOS/PRISM, and ALOS/AVNIR-2 reveal that the flood reduced the lake area from 0.0422 km² to 0.0083 km², discharging 437 000 m³ of water. This glacier lake was not present in a Landsat 7 ETM+ image taken on 26 April 2008. It formed rapidly over just two and half months from early May to the late July, when large amounts of snow and glacier melt water became trapped in a basin in the glacier terminus area, blocked by temporary closure of the drainage channel through the terminal moraine that included much dead-ice. In the same mountain region, most other glacier-lake expansions were not particularly large during the period from 1999–2008. Although events like the w-Zyndan glacier lake outburst occur infrequently in the high Central Asian mountains, such fast developing, short-lived lakes are particularly dangerous and not easy to monitor using satellite data. Appropriate measures to protect against such lake outburst hazards in this region include educating residents on glacier hazards and monitoring techniques, providing frequently updated maps of glacier lakes, and planning and monitoring land-use, including house locations.

A solar radiation database for Chile.

Science.gov (United States)

Molina, Alejandra; Falvey, Mark; Rondanelli, Roberto

2017-11-01

Chile hosts some of the sunniest places on earth, which has led to a growing solar energy industry in recent years. However, the lack of high resolution measurements of solar irradiance becomes a critical obstacle for both financing and design of solar installations. Besides the Atacama Desert, Chile displays a large array of "solar climates" due to large latitude and altitude variations, and so provides a useful testbed for the development of solar irradiance maps. Here a new public database for surface solar irradiance over Chile is presented. This database includes hourly irradiance from 2004 to 2016 at 90 m horizontal resolution over continental Chile. Our results are based on global reanalysis data to force a radiative transfer model for clear sky solar irradiance and an empirical model based on geostationary satellite data for cloudy conditions. The results have been validated using 140 surface solar irradiance stations throughout the country. Model mean percentage error in hourly time series of global horizontal irradiance is only 0.73%, considering both clear and cloudy days. The simplicity and accuracy of the model over a wide range of solar conditions provides confidence that the model can be easily generalized to other regions of the world.

Improving regional climate and hydrological forecasting following the record setting flooding across the Lake Ontario - St. Lawrence River system

Science.gov (United States)

Gronewold, A.; Seglenieks, F.; Bruxer, J.; Fortin, V.; Noel, J.

2017-12-01

In the spring of 2017, water levels across Lake Ontario and the upper St. Lawrence River exceeded record high levels, leading to widespread flooding, damage to property, and controversy over regional dam operating protocols. Only a few years earlier, water levels on Lakes Superior, Michigan, and Huron (upstream of Lake Ontario) had dropped to record low levels leading to speculation that either anthropogenic controls or climate change were leading to chronic water loss from the Great Lakes. The contrast between low water level conditions across Earth's largest lake system from the late 1990s through 2013, and the rapid rise prior to the flooding in early 2017, underscores the challenges of quantifying and forecasting hydrologic impacts of rising regional air and water temperatures (and associated changes in lake evaporation) and persistent increases in long-term precipitation. Here, we assess the hydrologic conditions leading to the recent record flooding across the Lake Ontario - St. Lawrence River system, with a particular emphasis on understanding the extent to which those conditions were consistent with observed and anticipated changes in historical and future climate, and the extent to which those conditions could have been anticipated through improvements in seasonal climate outlooks and hydrological forecasts.

A fugacity model for source determination of the Lake Baikal region pollution with polychlorinated Biphenyls

Energy Technology Data Exchange (ETDEWEB)

Sofiev, M. [Finnish Meteorological Inst., Helsinki (Finland); Galperin, M.; Maslyaev, A. [Inst. of Program Systems, Pereslavl-Zalesskiy (Russian Federation); McLachlan, M. [Stockholm Univ. (Sweden); Wania, F. [Toronto Univ. (Canada)

2004-09-15

PCBs were discovered in the Lake Baikal ecosystem by Malakhov et al. and Bobovnikova et al. A follow up to the initial study showed no decrease over 1981-1989 4, in contrast to what has been observed in other water bodies in the industrialised world. Further studies also showed the contamination in pinnipeds to be among the highest measured anywhere. Above studies and other data suggested a presence of a strong local PCB source (or several ones), which has had a widespread adverse effect for the whole region. To locate the source, Mamontov et al. collected samples from 34 sites over the region, the analysis of which showed a gradient of a factor of 1000, with the lowest concentrations at the north-east of Lake Baikal and the highest concentrations close to the city of Usolye Sibirskoye, a centre of the chemical industry in the Angara River valley. A continuous decrease in the soil contamination was observed along the path from Usolye Sibirskoye up the Angara River valley to Lake Baikal and from there north-eastward along the lake. These results indicate that there was (and perhaps still is) a major source of PCBs in the Usolye area, from where the PCBs are dispersed over the region. However, various obstacles prevent direct observations of potential sources. Therefore, a mathematical modelling approach was adopted in a currently ongoing INTAS project aiming to shed some more light on this problem. The model principles, setup and the results of the first experiments are presented in the current paper.

An Overview of Sediment Organic Matter Records of Human Eutrophication in the Laurentian Great Lakes Region

Energy Technology Data Exchange (ETDEWEB)

Meyers, Philip A. [University of Michigan, Department of Geological Sciences (United States)], E-mail: pameyers@umich.ed

2006-12-15

The isotopic and molecular compositions of organic matter buried in lake sediments provide information that helps to reconstruct past environmental conditions and to assess impacts of humans on local ecosystems. This overview of sedimentary records from the North American Great Lakes region describes examples of applications of organic geochemistry to paleolimnological reconstructions. These lakes experienced a succession of human-induced environmental changes that started after completion of the Erie Canal in 1825. Agricultural deforestation in the mid-nineteenth century released soil nutrients that increased algal productivity and caused an associated increase in algal biomarkers in sediment records. Eutrophication that accompanied magnified delivery of municipal nutrients to the lakes in the 1960s and 1970s created excursions to less negative {delta}{sup 13}C values in sediment organic matter. Increased organic carbon mass accumulation rates mirror the isotopic evidence of eutrophication in the Great Lakes.

Great Lakes Literacy Principles

Science.gov (United States)

Fortner, Rosanne W.; Manzo, Lyndsey

2011-03-01

Lakes Superior, Huron, Michigan, Ontario, and Erie together form North America's Great Lakes, a region that contains 20% of the world's fresh surface water and is home to roughly one quarter of the U.S. population (Figure 1). Supporting a $4 billion sport fishing industry, plus $16 billion annually in boating, 1.5 million U.S. jobs, and $62 billion in annual wages directly, the Great Lakes form the backbone of a regional economy that is vital to the United States as a whole (see http://www.miseagrant.umich.edu/downloads/economy/11-708-Great-Lakes-Jobs.pdf). Yet the grandeur and importance of this freshwater resource are little understood, not only by people in the rest of the country but also by many in the region itself. To help address this lack of knowledge, the Centers for Ocean Sciences Education Excellence (COSEE) Great Lakes, supported by the U.S. National Science Foundation and the National Oceanic and Atmospheric Administration, developed literacy principles for the Great Lakes to serve as a guide for education of students and the public. These “Great Lakes Literacy Principles” represent an understanding of the Great Lakes' influences on society and society's influences on the Great Lakes.

Tourism in Chile | CTIO

Science.gov (United States)

Program PIA Program GO-FAAR Program Other Opportunities Tourism Visits to Tololo Astro tourism in Chile Tourism in Chile Information for travelers Visit Tololo Media Relations News Press Release Publications ‹› You are here CTIO Home » Outreach » Tourism » Tourism in Chile Tourism in Chile Map of

Glacial lake inventory and lake outburst potential in Uzbekistan.

Science.gov (United States)

Petrov, Maxim A; Sabitov, Timur Y; Tomashevskaya, Irina G; Glazirin, Gleb E; Chernomorets, Sergey S; Savernyuk, Elena A; Tutubalina, Olga V; Petrakov, Dmitriy A; Sokolov, Leonid S; Dokukin, Mikhail D; Mountrakis, Giorgos; Ruiz-Villanueva, Virginia; Stoffel, Markus

2017-08-15

Climate change has been shown to increase the number of mountain lakes across various mountain ranges in the World. In Central Asia, and in particular on the territory of Uzbekistan, a detailed assessment of glacier lakes and their evolution over time is, however lacking. For this reason we created the first detailed inventory of mountain lakes of Uzbekistan based on recent (2002-2014) satellite observations using WorldView-2, SPOT5, and IKONOS imagery with a spatial resolution from 2 to 10m. This record was complemented with data from field studies of the last 50years. The previous data were mostly in the form of inventories of lakes, available in Soviet archives, and primarily included localized in-situ data. The inventory of mountain lakes presented here, by contrast, includes an overview of all lakes of the territory of Uzbekistan. Lakes were considered if they were located at altitudes above 1500m and if lakes had an area exceeding 100m 2 . As in other mountain regions of the World, the ongoing increase of air temperatures has led to an increase in lake number and area. Moreover, the frequency and overall number of lake outburst events have been on the rise as well. Therefore, we also present the first outburst assessment with an updated version of well-known approaches considering local climate features and event histories. As a result, out of the 242 lakes identified on the territory of Uzbekistan, 15% are considered prone to outburst, 10% of these lakes have been assigned low outburst potential and the remainder of the lakes have an average level of outburst potential. We conclude that the distribution of lakes by elevation shows a significant influence on lake area and hazard potential. No significant differences, by contrast, exist between the distribution of lake area, outburst potential, and lake location with respect to glaciers by regions. Copyright © 2017 Elsevier B.V. All rights reserved.

Distribution and habitat ecology of the sorediate species of Menegazzia (Parmeliaceae, lichenized Ascomycota in Chile Distribución y ecología de las especies sorediosas de Menegazzia (Parmeliaceae, Ascomycota liquenizado en Chile

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JARLE W BJERKE

2003-03-01

Full Text Available ABSTRACT The taxonomy and ecology of the sorediate species of Menegazzia from the southernmost regions of Chile and Argentina and the South Atlantic Islands was recently published, only with sporadic reports from the more northern regions. In the present work the distribution patterns and habitat ecology of the sorediate species are discussed, with emphasis on the area north of 48º S. Eleven species are treated. Menegazzia subpertusa, an epiphyte of sclerophyll scrubs, is recorded from South America for the first time (Chile and Argentina. Menegazzia neozelandica has a disjunct distribution in Chile, with occurrences in Fray Jorge (Fourth Region of Chile and on Islas Juan Fernández, and along the coast south of latitude 38º S. Menegazzia kawesqarica and M. tenuis are most common in the southernmost part of Chile, but are also found at high altitudes at lower latitudes. Additional treated species are M. chrysogaster, M. fumarprotocetrarica, M. globulifera, M. magellanica, M. norsorediata, M. sanguinascens and M. wandae. Several of the sorediate species are early colonisers of newly developed substrates. They show variable occurrences along light and humidity gradients. Distribution maps and a revised key are presented.Recientemente se han publicado datos sobre la taxonomía y ecología de las especies sorediosas de Menegazzia representadas en las regiones más australes de Chile y Argentina e islas del Atlántico Sur, además de registros esporádicos en zonas ubicadas más al norte en Chile. En este trabajo se discuten los patrones de distribución y la ecología del hábitat de 11 especies sorediosas, con especial enfásis en aquellas que se desarrollan al norte de los 48º S. Menegazzia subpertusa, un epífito de arbustos esclerófilos, se registra por primera vez en América (Chile y Argentina. Menegazzia neozelandica tiene una distribución discontinua en Chile; ha sido recolectada en Fray Jorge (Cuarta Región de Chile, Islas Juan Fern

Local to regional scale industrial heavy metal pollution recorded in sediments of large freshwater lakes in central Europe (lakes Geneva and Lucerne) over the last centuries.

Science.gov (United States)

Thevenon, Florian; Graham, Neil D; Chiaradia, Massimo; Arpagaus, Philippe; Wildi, Walter; Poté, John

2011-12-15

This research first focuses on the spatial and temporal patterns of heavy metals from contrasting environments (highly polluted to deepwater sites) of Lake Geneva. The mercury (Hg) and lead (Pb) records from two deepwater sites show that the heavy metal variations before the industrial period are primarily linked to natural weathering input of trace elements. By opposition, the discharge of industrial treated wastewaters into Vidy Bay of Lake Geneva during the second part of the 20th century, involved the sedimentation of highly metal-contaminated sediments in the area surrounding the WWTP outlet pipe discharge. Eventually, a new Pb isotope record of sediments from Lake Lucerne identifies the long-term increasing anthropogenic lead pollution after ca. 1500, probably due to the development of metallurgical activities during the High Middle Ages. These data furthermore allows to compare the recent anthropogenic sources of water pollution from three of the largest freshwater lakes of Western Europe (lakes Geneva, Lucerne, and Constance). High increases in Pb and Hg highlight the regional impact of industrial pollution after ca. 1750-1850, and the decrease of metal pollution in the 1980s due to the effects of remediation strategies such as the implementation of wastewater treatment plants (WWTPs). However, at all the studied sites, the recent metal concentrations remain higher than pre-industrial levels. Moreover, the local scale pollution data reveal two highly contaminated sites (>100 μg Pb/g dry weight sediment) by industrial activities, during the late-19th and early-20th centuries (Lake Lucerne) and during the second part of the 20th century (Vidy Bay of Lake Geneva). Overall, the regional scale pollution history inferred from the three large and deep perialpine lakes points out at the pollution of water systems by heavy metals during the last two centuries due to the discharge of industrial effluents. Copyright © 2011 Elsevier B.V. All rights reserved.

Evaluation of a rural demonstration program to increase seat belt use in the Great Lakes Region.

Science.gov (United States)

2009-03-01

Six States in the Great Lakes Region (Region 5) participated in a Rural Demonstration Program to increase seat belt : use in rural areas and among high-risk occupants, such as young males and occupants of pickup trucks. These : efforts, which include...

Síndrome pulmonar por hantavirus en población infantil. Chile: Regiones IX y X. 1998-2000

OpenAIRE

SOZA C., GUILLERMO; LORCA O., PEDRO; PUEBLA M., SERGIO; WENZEL M., MARISOL; NAVARRETE C., MARITZA; VILLAGRA C., ELIECER; MORA R., JUDITH; LEVIS C., SILVANA; AVILES A., GABRIELA

2000-01-01

El síndrome pulmonar por hantavirus (SPH) ha estado presente en Chile desde 1993 y ha sido detectado desde 1997 en la IX Región. Es una grave zoonosis con alta mortalidad, que afecta a gente joven incluyendo niños. Se ha estimado oportuno dar a conocer nuestra experiencia en la atención de 6 pacientes pediátricos, atendidos en las unidades de Cuidados Intensivos y Aislamiento en el Hospital Regional de Temuco, entre enero de 1998 y enero de 2000 mediante un estudio descriptivo de la experienc...

PeRL: a circum-Arctic Permafrost Region Pond and Lake database

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S. Muster

2017-06-01

Full Text Available Ponds and lakes are abundant in Arctic permafrost lowlands. They play an important role in Arctic wetland ecosystems by regulating carbon, water, and energy fluxes and providing freshwater habitats. However, ponds, i.e., waterbodies with surface areas smaller than 1. 0 × 104 m2, have not been inventoried on global and regional scales. The Permafrost Region Pond and Lake (PeRL database presents the results of a circum-Arctic effort to map ponds and lakes from modern (2002–2013 high-resolution aerial and satellite imagery with a resolution of 5 m or better. The database also includes historical imagery from 1948 to 1965 with a resolution of 6 m or better. PeRL includes 69 maps covering a wide range of environmental conditions from tundra to boreal regions and from continuous to discontinuous permafrost zones. Waterbody maps are linked to regional permafrost landscape maps which provide information on permafrost extent, ground ice volume, geology, and lithology. This paper describes waterbody classification and accuracy, and presents statistics of waterbody distribution for each site. Maps of permafrost landscapes in Alaska, Canada, and Russia are used to extrapolate waterbody statistics from the site level to regional landscape units. PeRL presents pond and lake estimates for a total area of 1. 4 × 106 km2 across the Arctic, about 17 % of the Arctic lowland ( <  300 m a.s.l. land surface area. PeRL waterbodies with sizes of 1. 0 × 106 m2 down to 1. 0 × 102 m2 contributed up to 21 % to the total water fraction. Waterbody density ranged from 1. 0 × 10 to 9. 4 × 101 km−2. Ponds are the dominant waterbody type by number in all landscapes representing 45–99 % of the total waterbody number. The implementation of PeRL size distributions in land surface models will greatly improve the investigation and projection of surface inundation and carbon fluxes in permafrost lowlands

Multiproxy approach revealing climate and cultural changes during the last 26kyrs in south-central Chile

Science.gov (United States)

Abarzua, Ana M.; Jarpa, Leonora; Martel, Alejandra; Vega, Rodrigo; Pino, Mario

2010-05-01

Multiproxy approach from Purén Lumaco Valley (38°S) describes the paleonvironmental history during the Last Maximum Glacial (LGM) in south-central Chile. Three sediment cores and severals AMS 14C dates were used to perform a complete pollen, diatoms, chironomids, and sedimentological records demonstrating the existence of a large and non profundal paleolake, between 25 and 20kyr BP. Some of these evidence are laminated silty-clay sediments (lacustrine rhythmites), associated with the presence of siderite mineral (FeCO3), besides biological proxies like Fragilaria construens and Stauroforma inermes (planctonic diatoms), and Dicrotendipes sp. and Tanytarsini tribe (littoral chironomids). The pollen ensemble reveals the first glacial refuge of Araucaria araucana forests in the low lands during the LGM. The lake was drained abruptly into a swamp/bog at 12kyr BP and colonized by Myrtaceae wet forest. This evidence suggest the dry/warm climate period of early Holocene in south-central Chile. Later, the sediments indicate variable lacustrine levels, and increase of charcoal particles, associated to current climatic conditions. The pollen spectrum dominated by Myrtaceae and Nothofagus contrasts with a strongly disturb current landscape. Actually, Purén-Lumaco valley constitutes a complex peat-bog system dominated by exotic grasses and forest species (Tritricum aestivum, Pinus radiata and Eucalyptus spp.). Some archaeological antecedents in the area document the human development at ca. 7yrs BP. The greatest archaeological characteristic present in the valley is the kuel, a Mapuche earth accumulation. The presence and extension of almost 300 kuel in the valley reflect the social/economic development, and partly explains why the region was the major resistance area for Spanish colonizer during XVI-XVII centuries. Also the archaeological findings reveal the presence of maize pollen (Zea mays) within their food consumption. The influence of climate and human impact in

Viability of Green Roofs as a Flood Mitigation Element in the Central Region of Chile

Directory of Open Access Journals (Sweden)

Daniel Mora-Melià

2018-04-01

Full Text Available Population increase and urban development over the last 20 years in Chile have outgrown most rainwater drainage and evacuation systems. Many cities located in the central region suffer from frequent floods in some of their sectors during winter rainfall events. In addition, the lack of green spaces in these cities leads to biodiversity loss, increasing temperatures, greater energy demands, etc. Green roofs offer a solution that can mitigate climate change by reducing the runoff in cities with extensive, highly impermeable areas. This work analyses the installation of green roofs as a potential solution to the sectorial floods suffered by many cities in central Chile. The methodology includes the identification of conflictive sectors in the city of Curicó, hydrological modelling with the Storm Water Management Model (SWMM software, the consideration of different distributions and types of green roof surfaces, and computational simulations to determine the feasibility of green roofs for preventing floods. The results show that, for moderate rainfall events, all studied sectors could avoid flooding if at least 50% of the surrounding area had green roofs (irrespective of the type of green roof. In contrast, in the presence of strong rainfall events, only some semi-extensive and extensive green roofs covering 60% to 95% of the surrounding area, respectively, could prevent flooding.

Postglacial uplift of the eastern Gulf of Finland-Lake Ladoga region: models and observations

Science.gov (United States)

Amantov, Aleksey; Fjeldskaar, Willy; Amantova, Marina

2015-04-01

The eastern Gulf of Finland - Lake Ladoga region - is at the peripheral part of the Fennoscandian post-glacial uplift. We compared different modeling results for this region with observations, including our revision of geomorphological traces of paleo shorelevel. As in many parts of the general Baltic-White Sea bedrock lowland at the margin of the Fennoscandian Shield, the bedrock landscape was modified by glaciers, but it was also the major controlling factor for the history of glacial grows and decays. First-order landforms of this segment are: Lake Ladoga-Lake Ilmen lowland, Lembolovo High of the Karelic Isthmus and Neva-Gulf of Finland lowland. The range of the bedrock topography is close to 350 m. The landforms reflect different glacial behavior during stadials, with fast movement and strong erosion in northern Ladoga, but passive motion and accumulation around Lembolovo High. The differences influenced the ice sheet and deglaciation history. The shore level displacements in this area are slightly different than westwards in the Baltic area; the shoreline tilts are usually lower in southern-central part of the eastern Gulf of Finland-lake Ladoga region. For example, the shoreline tilts at 11 600 BP in the Baltic Ice Lake in the south-east range from 0.55 to 0.31 m/km. The slope of the Ancylus shoreline varies from 0.12 to 0.18 m/km, increasing to almost the double in the north-western area. Similarly, the Littorina shore level is tilted only 0.08 m/km, rising to 0.14 m/km in the north-west. We have used this data in our high resolution modeling involving glacial isostasy, hydro isostasy, sediment isostasy, and gravity field changes. The mopdeling is based on Earth rheology model with a low-viscosity asthenosphere of thickness less than 150 km and viscosity less than 7.0x10**19 Pa s above a mantle of viscosity 10**21 Pa s, and an effective elastic lithosphere thickness of 30-40 km (flexural rigidity 10**24 Nm). The specific uplift features in the area are

Field survey of the 16 September 2015 Chile tsunami

Science.gov (United States)

Lagos, Marcelo; Fritz, Hermann M.

2016-04-01

On the evening of 16 September, 2015 a magnitude Mw 8.3 earthquake occurred off the coast of central Chile's Coquimbo region. The ensuing tsunami caused significant inundation and damage in the Coquimbo or 4th region and mostly minor effects in neighbouring 3rd and 5th regions. Fortunately, ancestral knowledge from the past 1922 and 1943 tsunamis in the region along with the catastrophic 2010 Maule and recent 2014 tsunamis, as well as tsunami education and evacuation exercises prompted most coastal residents to spontaneously evacuate to high ground after the earthquake. There were a few tsunami victims; while a handful of fatalities were associated to earthquake induced building collapses and the physical stress of tsunami evacuation. The international scientist joined the local effort from September 20 to 26, 2015. The international tsunami survey team (ITST) interviewed numerous eyewitnesses and documented flow depths, runup heights, inundation distances, sediment deposition, damage patterns, performance of the navigation infrastructure and impact on the natural environment. The ITST covered a 500 km stretch of coastline from Caleta Chañaral de Aceituno (28.8° S) south of Huasco down to Llolleo near San Antonio (33.6° S). We surveyed more than 40 locations and recorded more than 100 tsunami and runup heights with differential GPS and integrated laser range finders. The tsunami impact peaked at Caleta Totoral near Punta Aldea with both tsunami and runup heights exceeding 10 m as surveyed on September 22 and broadcasted nationwide that evening. Runup exceeded 10 m at a second uninhabited location some 15 km south of Caleta Totoral. A significant variation in tsunami impact was observed along the coastlines of central Chile at local and regional scales. The tsunami occurred in the evening hours limiting the availability of eyewitness video footages. Observations from the 2015 Chile tsunami are compared against the 1922, 1943, 2010 and 2014 Chile tsunamis. The

Yellowstone Lake Nanoarchaeota

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Scott eClingenpeel

2013-09-01

Full Text Available Considerable Nanoarchaeota novelty and diversity were encountered in Yellowstone Lake, Yellowstone National Park, where sampling targeted lake floor hydrothermal vent fluids, streamers and sediments associated with these vents, and in planktonic photic zones in three different regions of the lake. Significant homonucleotide repeats (HR were observed in pyrosequence reads and in near full-length Sanger sequences, averaging 112 HR per 1,349 bp clone and could confound diversity estimates derived from pyrosequencing, resulting in false nucleotide insertions or deletions (indels. However, Sanger sequencing of two different sets of PCR clones (110 bp, 1349 bp demonstrated that at least some of these indels are real. The majority of the Nanoarchaeota PCR amplicons were vent associated; however, curiously, one relatively small Nanoarchaeota OTU (70 pyrosequencing reads was only found in photic zone water samples obtained from a region of the lake furthest removed from the hydrothermal regions of the lake. Extensive pyrosequencing failed to demonstrate the presence of an Ignicoccus lineage in this lake, suggesting the Nanoarchaeota in this environment are associated with novel Archaea hosts. Defined phylogroups based on near full-length PCR clones document the significant Nanoarchaeota 16S rRNA gene diversity in this lake and firmly establish a terrestrial clade distinct from the marine Nanoarcheota as well as from other geographical locations.

Hydraulic fracturing and the Crooked Lake Sequences: Insights gleaned from regional seismic networks

Science.gov (United States)

Schultz, Ryan; Stern, Virginia; Novakovic, Mark; Atkinson, Gail; Gu, Yu Jeffrey

2015-04-01

Within central Alberta, Canada, a new sequence of earthquakes has been recognized as of 1 December 2013 in a region of previous seismic quiescence near Crooked Lake, ~30 km west of the town of Fox Creek. We utilize a cross-correlation detection algorithm to detect more than 160 events to the end of 2014, which is temporally distinguished into five subsequences. This observation is corroborated by the uniqueness of waveforms clustered by subsequence. The Crooked Lake Sequences have come under scrutiny due to its strong temporal correlation (>99.99%) to the timing of hydraulic fracturing operations in the Duvernay Formation. We assert that individual subsequences are related to fracturing stimulation and, despite adverse initial station geometry, double-difference techniques allow us to spatially relate each cluster back to a unique horizontal well. Overall, we find that seismicity in the Crooked Lake Sequences is consistent with first-order observations of hydraulic fracturing induced seismicity.

Regional-scale analysis of lake outburst hazards in the southwestern Pamir, Tajikistan, based on remote sensing and GIS

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M. Mergili

2011-05-01

Full Text Available This paper presents an analysis of the hazards emanating from the sudden drainage of alpine lakes in South-Western Tajik Pamir. In the last 40 yr, several new lakes have formed in the front of retreating glacier tongues, and existing lakes have grown. Other lakes are dammed by landslide deposits or older moraines. In 2002, sudden drainage of a glacial lake in the area triggered a catastrophic debris flow. Building on existing approaches, a rating scheme was devised allowing quick, regional-scale identification of potentially hazardous lakes and possible impact areas. This approach relies on GIS, remote sensing and empirical modelling, largely based on medium-resolution international datasets. Out of the 428 lakes mapped in the area, 6 were rated very hazardous and 34 hazardous. This classification was used for the selection of lakes requiring in-depth investigation. Selected cases are presented and discussed in order to understand the potentials and limitations of the approach used. Such an understanding is essential for the appropriate application of the methodology for risk mitigation purposes.

Vertical transmission of Trypanosoma cruzi in the Province of Choapa, IV Region, Chile: Preliminary Report (2005-2008

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Werner Apt

2010-01-01

Full Text Available Congenital Chagas disease acquired special importance in Chile after the certification of the control of Triatoma infestans and transmission by blood donors affected with Trypanosoma cruzi. In order to establish adequate protocols for intervention and control in infected mother-neonate pairs in endemic zones of Chagas disease, we present partial results (2005-2008 of a pilot project which is being carried out in the Province of Choapa, IV Region, Chile, whose objectives are: determine the current prevalence of the disease in pregnant women, estimate the incidence of vertical transmission of T. cruzi to newborns, determine the lineages of the parasite present in mothers who do and do not transmit the disease, determine the prevalence of Chagas disease in maternal grandmothers of neonates and study placental histopathology. Preliminary results indicated that in this study period, 3.7% of the women who gave birth in the Province have Chagas disease and 2.5% of their newborns were infected. The most frequent T. cruzi genotypes found in mothers studied during pregnancy were TCI and TCIId, either alone or in mixed infections. A high percentage (74.3% of the grandmothers studied was infected with the parasite. In 29 placentas from mothers with Chagas disease we observed edema, necrosis, fibrinoid deposits and slight lymphoplasmocyte infiltration. In three placentas we found erythroblastosis and in one of them amastigote forms of T. cruzi; this was one of the cases of congenital infection. The evaluation of the diagnostic and control protocols generated will allow us to determine if it has been possible to modify the natural history of vertical transmission of T. cruzi in Chile.

Local to regional scale industrial heavy metal pollution recorded in sediments of large freshwater lakes in central Europe (lakes Geneva and Lucerne) over the last centuries

Energy Technology Data Exchange (ETDEWEB)

Thevenon, Florian, E-mail: Florian.Thevenon@yahoo.fr [Institute F.-A. Forel, University of Geneva, Versoix (Switzerland); Graham, Neil D. [Institute F.-A. Forel, University of Geneva, Versoix (Switzerland); Chiaradia, Massimo [Department of Mineralogy, University of Geneva, Geneva (Switzerland); Arpagaus, Philippe; Wildi, Walter; Pote, John [Institute F.-A. Forel, University of Geneva, Versoix (Switzerland)

2011-12-15

This research first focuses on the spatial and temporal patterns of heavy metals from contrasting environments (highly polluted to deepwater sites) of Lake Geneva. The mercury (Hg) and lead (Pb) records from two deepwater sites show that the heavy metal variations before the industrial period are primarily linked to natural weathering input of trace elements. By opposition, the discharge of industrial treated wastewaters into Vidy Bay of Lake Geneva during the second part of the 20th century, involved the sedimentation of highly metal-contaminated sediments in the area surrounding the WWTP outlet pipe discharge. Eventually, a new Pb isotope record of sediments from Lake Lucerne identifies the long-term increasing anthropogenic lead pollution after ca. 1500, probably due to the development of metallurgical activities during the High Middle Ages. These data furthermore allows to compare the recent anthropogenic sources of water pollution from three of the largest freshwater lakes of Western Europe (lakes Geneva, Lucerne, and Constance). High increases in Pb and Hg highlight the regional impact of industrial pollution after ca. 1750-1850, and the decrease of metal pollution in the 1980s due to the effects of remediation strategies such as the implementation of wastewater treatment plants (WWTPs). However, at all the studied sites, the recent metal concentrations remain higher than pre-industrial levels. Moreover, the local scale pollution data reveal two highly contaminated sites (> 100 {mu}g Pb/g dry weight sediment) by industrial activities, during the late-19th and early-20th centuries (Lake Lucerne) and during the second part of the 20th century (Vidy Bay of Lake Geneva). Overall, the regional scale pollution history inferred from the three large and deep perialpine lakes points out at the pollution of water systems by heavy metals during the last two centuries due to the discharge of industrial effluents. Highlights: Black-Right-Pointing-Pointer Natural sources

Historical changes to Lake Washington and route of the Lake Washington Ship Canal, King County, Washington

Science.gov (United States)

Chrzastowski, Michael J.

1983-01-01

Lake Washington, in the midst of the greater Seattle metropolitan area of the Puget Sound region (fig. 1), is an exceptional commercial, recreational, and esthetic resource for the region . In the past 130 years, Lake Washington has been changed from a " wild " lake in a wilderness setting to a regulated lake surrounded by a growing metropolis--a transformation that provides an unusual opportunity to study changes to a lake's shoreline and hydrologic characteristics -resulting from urbanization.

Chile a jeho místo v integračních procesech Latinské Ameriky

OpenAIRE

Netuka, Petr

2004-01-01

Thesis briefly mentions history of Chile and introduces three efforts for regional integration - Free Trade Area of the Americas, Andean Community of Nations and Mercosur. In next chapters, bilateral relations of Chile to four other countries are described, namely relations to its neighbours (Argentina, Bolivia and Peru) and to Brazil as a largest economy of the Latin America. The goal of the work is to analyse an effort of Chile for regional integration.

Use of Satellite and In Situ Reflectance Data for Lake Water Color Characterization in the Everest Himalayan Region

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Erica Matta

2017-02-01

Full Text Available This study applied remote sensing techniques to the study of water color in Himalayan glacial lakes as a proxy of suspended solid load. In situ measurements gathered in 5 lakes in October 2014 during satellite data acquisition enabled the characterization of water reflectance and clarity and supported image processing. Field data analysis led to a distinction between 3 water colors and a consequent lake water color classification on a regional scale from Landsat-8 data previously corrected for atmospheric and adjacency effects. Several morphometric parameters (lake size and shape, distance between lake and glacier were also computed for the lakes thus classified. The results showed spatial and temporal variations in lake water color, suggestive of relationships between glacier shrinkage and the presence of brighter and more turbid water. A finer-scale analysis of the spatial variability of water reflectance on Chola Lake (based on GeoEye-1 data captured on 18 October 2014 showed the contribution of water component absorption from the inflow. Overall, the findings support further research to monitor Himalayan lakes using both Landsat-8 and Sentinel-2 (with its improved resolutions.

Regional nitrogen budget of the Lake Victoria Basin, East Africa: syntheses, uncertainties and perspectives

Science.gov (United States)

Zhou, Minghua; Brandt, Patric; Pelster, David; Rufino, Mariana C.; Robinson, Timothy; Butterbach-Bahl, Klaus

2014-10-01

Using the net anthropogenic nitrogen input (NANI) approach we estimated the N budget for the Lake Victoria Basin in East Africa. The NANI of the basin ranged from 887 to 3008 kg N km-2 yr-1 (mean: 1827 kg N km-2 yr-1) for the period 1995-2000. The net nitrogen release at basin level is due primarily to livestock and human consumption of feed and foods, contributing between 69% and 85%. Atmospheric oxidized N deposition contributed approximately 14% to the NANI of the Lake Victoria Basin, while either synthetic N fertilizer imports or biological N fixations only contributed less than 6% to the regional NANI. Due to the low N imports of feed and food products (export to Lake Victoria accounted for 16%, which is much lower than for watersheds located in Europe and USA (25%). A significant reduction of the uncertainty of our N budget estimate for Lake Victoria Basin would be possible if better data on livestock systems and riverine N export were available. Our study indicates that at present soil N mining is the main source of nitrogen in the Lake Victoria Basin. Thus, sustainable N management requires increasing agricultural N inputs to guarantee food security and rehabilitation and protection of soils to minimize environmental costs. Moreover, to reduce N pollution of the lake, improving management of human and animal wastes needs to be carefully considered in future.

Great Lakes Restoration Initiative Great Lakes Mussel Watch(2009-2014)

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National Oceanic and Atmospheric Administration, Department of Commerce — Following the inception of the Great Lakes Restoration Initiative (GLRI) to address the significant environmental issues plaguing the Great Lakes region, the...

Sediment trace metal profiles in lakes of Killarney Park, Canada from regional to continental influence

International Nuclear Information System (INIS)

Belzile, Nelson; Chen Yuwei; Gunn, John M.; Dixit, Sushil S.

2004-01-01

The lakes in Killarney Provincial Park (KPP) located 40-60 km southwest of Sudbury, Ontario are beginning to recover after decades of being severely affected by acidification and atmospheric pollutants. Detailed profiles of acid-recoverable trace elements (As. Cd, Cu, Co. Fe, Mn, Ni, Pb and Zn) were obtained after aqua regia digestion and ICP-OES analysis of sediment cores taken from six Park lakes. Results permitted the identification of two types of profiles. The first type applies to elements such as Fe, Mn, As and Co for which historical deposition and recent recovery are strongly masked by diagenetic remobilization. The second type of profile applies to elements such as Cd, Cu, Ni, Pb and Zn on which the history of industrialisation in North America and mining activities in Sudbury can be superimposed. Based on sediment data of trace elements less affected by diagenetic remobilization (Cd, Cu, Ni, Pb, Zn), chemical recovery indices can be estimated from depth profiles. Indices of maximum (C p ) and surface (C s ) contamination were calculated by dividing the concentration of a given metal by the pre-industrial level. The ratio of the two indices provided a simple estimation of the chemical recovery of lakes that does not consider the influence of the watershed or the lake pH. Profiles of metals in sediment of KPP complement the water quality monitoring data and tend to indicate that this area is in transition from dominant influence of regional pollution sources to becoming controlled by continental atmospheric deposition. - Lakes in Killarney Park are in transition from being impacted by regional pollution to being controlled by continental atmospheric deposition

[Teenage fecundity rates in Chile: a serious public health problem].

Science.gov (United States)

Molina C, Ramiro; Molina G, Temístocles; González A, Electra

2007-01-01

Teenage fecundity rates are an indicator of epidemiological discrimination in developing countries. To study fertility rates of girls under 14 years of age in Chile from 1993 to 2003. Information of children born alive from mothers aged 10 to 15 years, was obtained from the Chilean National Institute of Statistics. Age segmented population data was obtained from the Ministry of Health. Trends were analyzed by regions and single ages. The rates in communities of the Metropolitan Region were compared. Between 1993 and 2003, there was an increasing trend in fecundity rates, ratios and crude numbers. These rates duplicate from 14 to 15 years of age. In the Metropolitan Region, the fecundity ratios of communities with lower economical incomes is seven times greater than those with higher incomes. During 2003, the fecundity rates in Chile were 100 and 10 higher than those of Holland and Sweden in 1981. In developing countries with very low infant mortality rates such as Chile, the high fecundity rates of young girls is an indicator of a deficient human and social development. Sexual Education and Health Services for adolescents are essential to prevent this public health problem.

Remote sensing estimation of the total phosphorus concentration in a large lake using band combinations and regional multivariate statistical modeling techniques.

Science.gov (United States)

Gao, Yongnian; Gao, Junfeng; Yin, Hongbin; Liu, Chuansheng; Xia, Ting; Wang, Jing; Huang, Qi

2015-03-15

Remote sensing has been widely used for ater quality monitoring, but most of these monitoring studies have only focused on a few water quality variables, such as chlorophyll-a, turbidity, and total suspended solids, which have typically been considered optically active variables. Remote sensing presents a challenge in estimating the phosphorus concentration in water. The total phosphorus (TP) in lakes has been estimated from remotely sensed observations, primarily using the simple individual band ratio or their natural logarithm and the statistical regression method based on the field TP data and the spectral reflectance. In this study, we investigated the possibility of establishing a spatial modeling scheme to estimate the TP concentration of a large lake from multi-spectral satellite imagery using band combinations and regional multivariate statistical modeling techniques, and we tested the applicability of the spatial modeling scheme. The results showed that HJ-1A CCD multi-spectral satellite imagery can be used to estimate the TP concentration in a lake. The correlation and regression analysis showed a highly significant positive relationship between the TP concentration and certain remotely sensed combination variables. The proposed modeling scheme had a higher accuracy for the TP concentration estimation in the large lake compared with the traditional individual band ratio method and the whole-lake scale regression-modeling scheme. The TP concentration values showed a clear spatial variability and were high in western Lake Chaohu and relatively low in eastern Lake Chaohu. The northernmost portion, the northeastern coastal zone and the southeastern portion of western Lake Chaohu had the highest TP concentrations, and the other regions had the lowest TP concentration values, except for the coastal zone of eastern Lake Chaohu. These results strongly suggested that the proposed modeling scheme, i.e., the band combinations and the regional multivariate

Regional environment and hydrology changes documented by lake sediments from Lake Dalianhai, northeastern Tibetan Plateau since the last glacial maximum and their relationship with Asian summer monsoon variability

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Wu, D.; Chen, F.; Zhou, A.; Abbott, M. B.

2016-12-01

Variability of the Asian summer monsoon (ASM) significantly affects environment and hydrology conditions within its area of influence, as well as economic and social development. Thus it is important to investigate the variability of the ASM on various time-scales and to explore its underlying forcing mechanisms, in order to improve our ability to predict the long-term trends of regional and global climate. Northeastern Tibetan Plateau, a margin area of modern ASM, is sensitive to summer monsoon changes. Existing paleoclimate records from this region contain conflicting evidence for the timing of summer monsoon advance into this region: an early arrival pre-Younger Dryas or a late arrival at the beginning of the Holocene. In addition, it is also debated that whether the Holocene ASM maximum in this region occurred during the early Holocene or the middle Holocene. Here we present a high-resolution record of a 52-m drilling core from Lake Dalianhai in this region. Multiply geochemistry indexes were obtained from the sediment core. 22 AMS 14C data from plant remains and bulk organic matters illustrate that the upper 52 m core covered the whole period since the last glacial maximum (LGM). The results generally indicate that the Lake Dalianhai was occupied by very shallow water body with eolian sand surrounding the lake from 20 to 15 ka BP (1ka=1000 cal yr). With the beginning of the B/A warm period, the sedimentary sequence changed to grey lacustrine clay abruptly. The sedimentary environment was relatively stable under a high lake level state during the B/A period which was marked with fine mean grain size, and high exogenous detrital element content (such as Al, K, Ti and Rb), but with low organic matter content. This perhaps was caused by the increasing of ASM precipitation. Increased contents of element Ca, Sr, and Br, as well as TOC and TN, highlight the increase of ASM during the Holocene. However, reddish lacustrine clay with lower magnetic susceptibility and

University Support in the Development of Regional Entrepreneurial Activity: An Exploratory Study from Chile

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Carlos Poblete

2013-01-01

Full Text Available The theoretical literature has explored the potential benefits of the interaction between universities and entrepreneurs and there is some empirical evidence that supports the positive impact of entrepreneurship education in the subsequent propensity to become an entrepreneur. The purpose of this paper is study if higher education for entrepreneurship is reflected in entrepreneurship activities at the regional level. Replicating the methodology used by Coduras, Urban, Rojas and Martínez (2008 in Spain, we compare, in an exploratory way, the experience in Chile using data from the Global Entrepreneurship Monitor (GEM. The main results indicate that there is low interaction between entrepreneurs and universities and there is not enough impact to significantly affect entrepreneurial activity. Moreover, entrepreneurship education does not increase intentions to be an entrepreneur.

Occurrence and levels of glyphosate and AMPA in shallow lakes from the Pampean and Patagonian regions of Argentina.

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Castro Berman, M; Marino, D J G; Quiroga, María Victoria; Zagarese, Horacio

2018-06-01

Glyphosate (N-(phosphonomethyl)glycine) is a broad-spectrum systemic herbicide used to kill weeds that compete with commercial crops. In Argentina, the use of glyphosate-based herbicides increased dramatically (up to ∼200,000 tons on 2012) since the introduction of glyphosate-resistant crops, such as transgenic soy and resistant corn, and the adoption of non-till practices in the 1990's. Sallow lakes within the Pampa region may be potentially impacted by continuous herbicide usage. We surveyed 52 shallow lakes from the Pampa region (Buenos Aires Province, Argentina) to assess the occurrence and concentrations of glyphosate and its main degradation product (AMPA). For comparison, we also sampled 24 shallow lakes from an area with no agricultural use of glyphosate (Northern Patagonia). Glyphosate and AMPA were analyzed by UPLC-MS/MS ESI (±) in lake water, suspended particulate matter (SPM), and sediment samples. Within the Pampa region, glyphosate residues were detected in >40% of samples. Glyphosate residues were detected more frequently in sediment and surface water than in SPM samples. The mean (maximum) concentrations of glyphosate were 2.11 (4.52) μg l -1 for surface water; 0.10 (0.13) μg l -1 for SPM and 10.47 (20.34) μg kg -1 for sediment samples, respectively. Whereas, mean (maximum) concentrations of AMPA were 0.84 and (0.90) μg l -1 for surface water; 0.07 (0.07) μg l -1 for SPM; and 22.53 (32.89) μg kg -1 for sediment samples. The herbicide was not detected in samples from the Patagonian region. To our knowledge, this is the first study reporting the occurrence and concentrations of the herbicide in freshwater lakes of Argentina. Copyright © 2018 Elsevier Ltd. All rights reserved.

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... complex knowledge economy demands economic, social and environmental data ... Region: Brazil, South America, Chile, Colombia, Uruguay, North and Central ... Labour Market Regulations, Outcomes and Income Distribution in Colombia ...

Position paper on renewable energies and nature protection in European lake regions

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Anon.

2006-07-01

The man-made climate change is a central challenge of the lakes protection world wide in this century. By 2080, particularly in lake regions, the average temperature may rise - above all during the summer months - 2 to 5 degrees Celsius. Additionally, many regions will probably experience changes in rainfall (shift from summer to winter rainfalls) respectively declining rainfall in summer. These changes will have strong negative impacts on the people as well as on fauna and flora. The Solar Lakes Initiative is an approach of the Living Lakes-partners to tackle this vital problem. Focal points of this initiative are energy saving, energy efficiency and the use of renewable energies. The reason for this climate development is the growing discharge of greenhouse gases such as carbon dioxide and methane. Half of the man made greenhouse effect is due to CO2 emissions from energy supply. Therefore the international policy must aim at avoiding respectively clearly limiting any further temperature rise. An central contribution to solve this problem is the promotion and expansion of renewable energies. GNF calls for the implementation of the EU Guidelines on Renewable Energies determining a minimum share of 12% of clean energies in the total energy consumption by 2010. Additionally GNF supports the call of different environmental organisations and the EU Parliament for fixing a 25% target for renewable energies in the EU's overall energy consumption by 2020. GNF emphasises its attitude to support the nuclear power phase-out plans and its rejection to prolong the period of operation of the existing nuclear power plants in Germany. The governments in the EU should win over the interests of the energy industry and create basic conditions for the planned nuclear power phase-out. Legal regulations for power input rates such as the Renewable Energy Resources Act (EEG) have proved very useful. GNF supports the continuation and extension of the EEG in Germany to promote the

PILOT STUDIES WITH A PHOTOGRAMMETRIC GLACIER LAKE OUTBURST FLOOD EARLY WARNING SYSTEM

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H. G. Maas

2012-07-01

Full Text Available Glacier Lake Outburst Floods (GLOFs depict an environmental risk with an increasing damage potential in many regions of the world. GLOFs are often caused by glacier margin lakes, which suddenly find a drainage path underneath the bottom of a glacier, which is destabilized and retreating as a consequence of local or global climate changes. In a typical GLOF event, a glacier margin lake may drain completely in 24 hours, causing a large flood wave in the area downstream the glacier. The paper documents some recent GLOF events in the Northern Patagonian Icefield (Chile and presents a terrestrial photogrammetric glacier margin lake monitoring system. The system is based on a camera taking images at regular time intervals. In these images, variations of the water level can be detected by tracking the water-land interface at pre-defined image spots. Due to the drainage mechanism, which is characterized by progressive erosion and melting at the bottom of the glacier, GLOFs are indicated by a progressive water level drop in the lake. Water level changes may be detected with subpixel accuracy by image sequence processing methods. If a 3D model of the lake bottom topography (or at least one height profile through the lake exists, water level changes in monoscopic image sequences may be transformed into volume loss. The basic idea herein is the intersection of a terrain profile with a water level detected in the image and projected into object space. The camera orientation is determined through a GPS-supported photogrammetric network. Camera orientation changes, which may for instance be induced by wind, can be compensated by tracking some fiducial marks in the image. The system has been used in a pilot study at two glacier margin lakes in the Northern Patagonian Icefield. These lakes have a depth of about 80 - 100 meters. The larger one has a length of 5 km and a maximum volume of about 200,000,000 cubic meters. During the pilot study, several GLOF events

Environmental status of the Lake Michigan region. Volume 16. Amphibians and reptiles of the Lake Michigan drainage basin

Energy Technology Data Exchange (ETDEWEB)

Pentecost, E.D.; Vogt, R.C.

1976-07-01

The focus of this report is on regional distribution of the herpetofauna of the Lake Michigan Drainage Basin. The introduction includes a brief discussion of plant communities and their associated herpetofauna, and the importance of hibernacula and migration routes. Some aspects of the status, distribution, habitat, and life history of the amphibians and reptiles of the Basin are described in an annotated checklist. Special attention is given to uncommon and endangered species. Species range is shown on distribution maps.

Environmental status of the Lake Michigan region. Volume 16. Amphibians and reptiles of the Lake Michigan drainage basin

International Nuclear Information System (INIS)

Pentecost, E.D.; Vogt, R.C.

1976-07-01

The focus of this report is on regional distribution of the herpetofauna of the Lake Michigan Drainage Basin. The introduction includes a brief discussion of plant communities and their associated herpetofauna, and the importance of hibernacula and migration routes. Some aspects of the status, distribution, habitat, and life history of the amphibians and reptiles of the Basin are described in an annotated checklist. Special attention is given to uncommon and endangered species. Species range is shown on distribution maps

Climate Change in Africa: Impacts and Effects on the Inhabitants of the Lake Chad Region.

Science.gov (United States)

Abubakar, B.; Tahir, S. M.; Olisa, O.

2009-05-01

The Department of Energy and Climate Change defined climate as the average weather experienced over a long period. This includes temperature, wind and rainfall patterns. The climate of the Earth is not static, and has changed many times in response to a variety of natural causes. Due to human activities in emmiting green house gases has resulted the Earth to get warmed by 0.74°C over the last hundred years. Around 0.4°C of this warming has occurred since the 1970s. Climate is now one of the major phenomenon threatening lives and humanity in general since the beginning of industrial revolution. Climate exerts a profound influence on the lives of poor populations in the Lake Chad region of Africa who depend on fishing and crop cultivation for livelihood and sustenance, who are unprotected against climate-related diseases, who lacked secure access to water and food and who are vulnerable to hydro meteorological hazard. The effects of climate change on the study area are many and include diminishing resources and conflicts over the available limited water resources. The Lake Chad region is a fragile area with high climate variability and extremes of weather. As this inland water is used for domestic and agricultural purposes, salt mining, as well as transportation by Nigerians, Nigeriens, Chadian and Cameroonians, it is an area of trans-boundary water conflicts. This paper examines the part played by climate change in the decline of fishery resources and livelihood activities in the Lake Chad region. Data from field studies, structured interview and secondary sources show that fish catches and livelihood activities have declined tremendously in recent times due to several factors including overexploitation and increasing demands on the aquatic resources. Findings from the study show that droughty periods have resulted in the reduction of open lake water surface from about 25,000 km2 in 1973 to less than 2,000 km2 in the 1990s. This has led to the diminishing aquatic

Using Satellite Imagery to Monitor the Major Lakes; Case Study Lake Hamun

Science.gov (United States)

Norouzi, H.; Islam, R.; Bah, A.; AghaKouchak, A.

2015-12-01

Proper lakes function can ease the impact of floods and drought especially in arid and semi-arid regions. They are important environmentally and can directly affect human lives. Better understanding of the effect of climate change and human-driven changes on lakes would provide invaluable information for policy-makers and local people. As part of a comprehensive study, we aim to monitor the land-cover/ land-use changes in the world's major lakes using satellite observations. As a case study, Hamun Lake which is a pluvial Lake, also known as shallow Lake, located on the south-east of Iran and adjacent to Afghanistan, and Pakistan borders is investigated. The Lake is the main source of resources (agriculture, fishing and hunting) for the people around it and politically important in the region since it is shared among three different countries. The purpose of the research is to find the Lake's area from 1972 to 2015 and to see if any drought or water resources management has affected the lake. Analyzing satellites imagery from Landsat shows that the area of the Lake changes seasonally and intra-annually. Significant seasonal effects are found in 1975,1977, 1987, 1993, 1996, 1998, 2000, 2009 and 2011, as well as, substantial amount of shallow water is found throughout the years. The precipitation records as well as drought historical records are studied for the lake's basin. Meteorological studies suggest that the drought, decrease of rainfalls in the province and the improper management of the Lake have caused environmental, economic and geographical consequences. The results reveal that lake has experienced at least two prolong dryings since 1972 which drought cannot solely be blamed as main forcing factor.Proper lakes function can ease the impact of floods and drought especially in arid and semi-arid regions. They are important environmentally and can directly affect human lives. Better understanding of the effect of climate change and human-driven changes on lakes

Solidarity, territory and coercion. Explaining absence of conflict in the precarious agroindustrial workers, Region of Maule, Chile

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Fernando Baeza Rivas

2017-05-01

Full Text Available Based on 53 interviews of agribusiness workers in four companies in the region of Maule (Chile, we try to understand the reasons for the "split " between the objective indicators of precarious work and low levels of conflict in agriculture, from the analysis of subjective dissatisfaction of salaried with their employment. This could be explained by territorial factors, traditionalism of labor relations and the fear of sanctions for companies to conflict. The results emphasize the need to further deepen the subjective precariousness from conceptual and methodological frameworks that emphasize biographical and professional life of workers

Post-glacial recolonization of the Great Lakes region by the common gartersnake (Thamnophis sirtalis) inferred from mtDNA sequences.

Science.gov (United States)

Placyk, John S; Burghardt, Gordon M; Small, Randall L; King, Richard B; Casper, Gary S; Robinson, Jace W

2007-05-01

Pleistocene events played an important role in the differentiation of North American vertebrate populations. Michigan, in particular, and the Great Lakes region, in general, were greatly influenced by the last glaciation. While several hypotheses regarding the recolonization of this region have been advanced, none have been strongly supported. We generated 148 complete ND2 mitochondrial DNA (mtDNA) sequences from common gartersnake (Thamnophis sirtalis) populations throughout the Great Lakes region to evaluate phylogeographic patterns and population structure and to determine whether the distribution of haplotypic variants is related to the post-Pleistocene retreat of the Wisconsinan glacier. The common gartersnake was utilized, as it is believed to have been one of the primary vertebrate invaders of the Great Lakes region following the most recent period of glacial retreat and because it has been a model species for a variety of evolutionary, ecological, behavioral, and physiological studies. Several genetically distinct evolutionary lineages were supported by both genealogical and molecular population genetic analyses, although to different degrees. The geographic distribution of the majority of these lineages is interpreted as reflecting post-glacial recolonization dynamics during the late Pleistocene. These findings generally support previous hypotheses of range expansion in this region.

Deuterium content on surface waters VI to X Chile regions

International Nuclear Information System (INIS)

Aravena C, R; Pollastri J, A.; Suzuki S, O.

1984-01-01

One important parameter on any sitting study for a heavy water plant installation is the deuterium content of the feed water. Deuterium data on surface waters from differents areas located in the south of Chile, are presented. These results allow to idently some potential areas for a future heavy water plant. One of these areas, Lago Llanquihue, was sampled more in detail to study the vertical distribution and spatial variations. (Author)

Environmental status of the Lake Michigan region. Volume 6. Zoobenthos of Lake Michigan

Energy Technology Data Exchange (ETDEWEB)

Mozley, S.C.; Howmiller, R.P.

1977-09-01

This report summarizes Lake Michigan zoobenthic studies up to 1974, including reports of power-plant surveys. It describes ecologies of macroinvertebrate species and some microfauna, partly through use of data from other Great Lakes. The following are discussed: methodology of field surveys; zoobenthic indicators of pollution; zoobenthic effects on sediment-water exchanges; and numbers, biomass, and production of total macroinvertebrates. Prominent features of Lake Michigan zoobenthos include predominance of the amphipod Pontoporeia affinis, usefulness of tubificid oligochaetes in mapping environmental quality, and pronounced qualitative gradients in zoobenthos in relation to depth. Further research is needed on sampling methods, energy flow rates and pathways through benthic communities, factors limiting distribution of species near shore, and effects of macroinvertebrates on sediment chemistry and structure.

Evaluation of Water Quality Change of Brackish Lake in Snowy Cold Regions Accompanying Climate Change

Science.gov (United States)

Kudo, K.; Hasegawa, H.; Nakatsugawa, M.

2017-12-01

This study addresses evaluation of water quality change of brackish lake based on the estimation of hydrological quantities resulting from long-term hydrologic process accompanying climate change. For brackish lakes, such as Lake Abashiri in Eastern Hokkaido, there are concerns about water quality deterioration due to increases in water temperature and salinity. For estimating some hydrological quantities in the Abashiri River basin, including Lake Abashiri, we propose the following methods: 1) MRI-NHRCM20, a regional climate model based on the Representative Concentration Pathways adopted by IPCC AR5, 2) generalized extreme value distribution for correcting bias, 3) kriging adopted variogram for downscaling and 4) Long term Hydrologic Assessment model considering Snow process (LoHAS). In addition, we calculate the discharge from Abashiri River into Lake Abashiri by using estimated hydrological quantities and a tank model, and simulate impacts on water quality of Lake Abashiri due to climate change by setting necessary conditions, including the initial conditions of water temperature and water quality, the pollution load from the inflow rivers, the duration of ice cover and salt pale boundary. The result of the simulation of water quality indicates that climate change is expected to raise the water temperature of the lake surface by approximately 4°C and increase salinity of surface of the lake by approximately 4psu, also if salt pale boundary in the lake raises by approximately 2-m, the concentration of COD, T-N and T-P in the bottom of the lake might increase. The processes leading to these results are likely to be as follows: increased river water flows in along salt pale boundary in lake, causing dynamic flow of surface water; saline bottom water is entrained upward, where it mixes with surface water; and the shear force acting at salt pale boundary helps to increase the supply of salts from bottom saline water to the surface water. In the future, we will

The subduction erosion and mantle source region contamination model of Andean arc magmatism: Isotopic evidence from igneous rocks of central Chile

International Nuclear Information System (INIS)

Stern, Charles R

2001-01-01

Continental crust may be incorporated in mantle-derived Andean magmas as these magmas rise through the crust (Hildreth and Moorbath, 1988), or alternatively, crust may be tectonically transported into the mantle by subduction of trench sediments and subduction erosion of the continental margin, and then added into the mantle source region of Andean magmas (Stern, 1991). Since the mantle has relatively low Sr, Nd, and Pb concentrations compared to continental crust, differences in the isotopic compositions of magmas erupted in different region of the Andes may be produced by relatively small differences in the amount of subducted crust added to the mantle source region of these magmas. By comparison, significantly larger amounts of crust must be assimilated by mantle-derived magmas to produce isotopic differences of similar magnitude. Therefore, constraining the process by which continental crust is incorporated in Andean magmas has important implications for understanding the chemical cycling that takes place in the Andean subduction-related magma factory. Isotopic data suggest the incorporation of a greater proportion of crust in Andean magmas erupted at the northern portion of the Southern Volcanic Zone of central Chile compared to those erupted in the southern portion of the Southern Volcanic Zone of south central Chile (SSVZ) (Stern et al., 1984; Futa and Stern, 1988; Hildreth and Moorbath, 1988). The NSVZ occurs just south of the current locus of the subduction of the Juan Fernandez Ridge. The southward migration of the locus of subduction of this ridge has resulted in decreasing subduction angle below the NSVZ, the eastward migration of the volcanic front of the Andean arc, and an increase in the crustal thickness below the arc. These factors together have caused changes, since the middle Miocene, in the isotopic composition of Andean igneous rocks of central Chile. The data indicate a close chronologic relation between the southward migrations of the locus

Using Information and Communication Technologies to Prevent Suicide Among Secondary School Students in Two Regions of Chile: A Randomized Controlled Trial

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Franco Mascayano

2018-06-01

Full Text Available Background: There is an increasing concern for addressing suicide among adolescents in Latin America. Recent mental health policies encourage the development and implementation of preventive interventions for suicide. Such initiatives, however, have been scarcely developed, even in countries with solid mental health services such as Chile. The use of information and communications technology (ICT might contribute to create accessible, engaging, and innovative platforms to promote well-being and support for adolescents with mental health needs and suicide risk.Objective: To evaluate a program based on ICT to prevent suicide and enhance mental health among adolescents in Chile. Method: A cluster randomized controlled trial (RCT will be conducted including 428 high-school students aged 18–14 years in two regions of Chile. Study procedures will take place as follows: (1 design of the intervention model and creation of prototype; (2 selection and randomization of the participating public schools; (3 implementation of the 3-month intervention and evaluation at baseline, post-intervention period, and a 2-month follow-up. Suicidal ideation at the 2-month follow up is the primary outcome in this study. Secondary outcomes include negative psychological outcomes (e.g., stigma, depression, anxiety as well as a number of protective psychological and social factors. Indicators regarding the study implementation will be also gathered. Discussion: Here we describe a novel program based on technological devices and aimed to target youth suicide in Chile. This is the first clinical trial of such a program in Latin America, and to our knowledge, the first of its kind in any middle income country.Trial Registration: gov Identifier: NCT03514004

Statistical downscaling of sea-surface wind over the Peru-Chile upwelling region: diagnosing the impact of climate change from the IPSL-CM4 model

Energy Technology Data Exchange (ETDEWEB)

Goubanova, K. [CNES/CNRS/IRD/UPS, Laboratoire d' Etudes en Geophysique et Oceanographie Spatiale, Toulouse (France); Instituto del Mar del Peru, Callao (Peru); Echevin, V.; Terray, P. [IPSL/UPMC/IRD, Laboratoire d' Oceanographie et de Climatologie, Experimentation et Approches Numeriques, Paris (France); Dewitte, B. [CNES/CNRS/IRD/UPS, Laboratoire d' Etudes en Geophysique et Oceanographie Spatiale, Toulouse (France); Instituto del Mar del Peru, Callao (Peru); Instituto Geofisico del Peru, Lima (Peru); Codron, F. [UPMC/CNRS, Laboratoire de Meteorologie Dynamique, Paris (France); Takahashi, K. [Instituto Geofisico del Peru, Lima (Peru); Vrac, M. [IPSL/CNRS/CEA/UVSQ, Laboratoire des Sciences du Climat et de l' Environnement, Gif-sur-Yvette (France)

2011-04-15

The key aspect of the ocean circulation off Peru-Chile is the wind-driven upwelling of deep, cold, nutrient-rich waters that promote a rich marine ecosystem. It has been suggested that global warming may be associated with an intensification of upwelling-favorable winds. However, the lack of high-resolution long-term observations has been a limitation for a quantitative analysis of this process. In this study, we use a statistical downscaling method to assess the regional impact of climate change on the sea-surface wind over the Peru-Chile upwelling region as simulated by the global coupled general circulation model IPSL-CM4. Taking advantage of the high-resolution QuikSCAT wind product and of the NCEP reanalysis data, a statistical model based on multiple linear regressions is built for the daily mean meridional and zonal wind at 10 m for the period 2000-2008. The large-scale 10 m wind components and sea level pressure are used as regional circulation predictors. The skill of the downscaling method is assessed by comparing with the surface wind derived from the ERS satellite measurements, with in situ wind observations collected by ICOADS and through cross-validation. It is then applied to the outputs of the IPSL-CM4 model over stabilized periods of the pre-industrial, 2 x CO{sub 2} and 4 x CO{sub 2} IPCC climate scenarios. The results indicate that surface along-shore winds off central Chile (off central Peru) experience a significant intensification (weakening) during Austral winter (summer) in warmer climates. This is associated with a general decrease in intra-seasonal variability. (orig.)

Cooperation control strategies for China's cross-region pollution in a lake basin based on green reduction cost.

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Li, Changmin; Sun, Dong; Xie, Xiaoqiang; Xue, Jian

2016-05-01

The cross-region water pollution issue has always been the widespread concern around the world. It becomes especially critical for China due to the imbalance relates to environmental costs that have accompanied rapid growth of economy. Though the government makes great efforts to improve it, the potential for water pollution conflict is still great. We consider the problem of determining combined control strategies for China's cross-region lake pollution based on the environmental green costs. The problem is first formulated as a generalized bilevel mathematical program where the upper level consists in each region that reduces environmental green costs including three parts: the reduction cost, pollution permit trade cost and cost of environment damage, while the lower level is represented by pollution permit equilibrium market. Finally, we take an empirical analysis in Taihu lake. The numerical study shows that the minimum costs of both total and regional are obviously superior to the current processing costs, which provides theoretical basis for the price of emission permits. Today, China's rapid gross domestic product (GDP) growth has come at a very high cost, as real estate prices have skyrocketed, the wealth gap has widened, and environmental pollution has worsened. China's central government is urged to correct the GDP-oriented performance evaluation system that is used to judge administrative region leaders. The cross-region water pollution issue has become a troubling issue that urgently needs to be resolved in China. This paper will not only actively aid efforts to govern Lake Taihu and other cross-region valleys, but it will also provide a supplement for theoretical research on cross-region pollution issues.

Lake Morphometry for NHD Lakes in the Upper Portion of the Missouri Region 10 HUC

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U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

Lake Morphometry for NHD Lakes in the Lower Portion of the Missouri Region 10 HUC

Data.gov (United States)

U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

Hydrologic and Geomorphic Impacts of Glacial Lake Outburst Floods From Low-Order Tributaries

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McCoy, S. W.; Jacquet, J.; McGrath, D.; George, D. L.; Koschitzki, R.; Nimick, D.; Fahey, M. J.; Okuinghttons, J.

2017-12-01

Lakes dammed by glacial ice or moraines are common features in the headwaters of both glaciated and recently deglaciated catchments. These dams can fail releasing water in a glacial lake outburst flood (GLOF), which raises the question: do GLOFs from low-order tributaries significantly alter the hydrology and sediment transport regimes of the large mainstem rivers to which they drain? Here we use repeat satellite imagery, in situ measurements, and 2D hydrodynamic modeling to quantify the hydrologic and geomorphic changes that resulted from 22 GLOFs that occurred between 2008 and 2016 from Lago Cachet Dos, Patagonia, Chile. We find that the complicated flood path that includes two lakes and a broad floodplain can dampen peak discharges from over 15,000 m³/s at the source lake to generally less than 2,000 m³/s where the floods enter the mainstem Rio Baker, 40 km downstream. Despite this dampening of GLOF peak discharge, peak discharges still exceeded the peak annual discharge of the Rio Baker, the largest river in Chile by volume, by 1 to 2 times, which in turn increased the frequency and magnitude of flood events. We also document the sediment dynamics in the source lake, where we find that over 25,000,000 m³ of stored sediment was removed during the GLOF cycle that began in 2008. Further downstream, repeat satellite imagery reveals that the large discharges associated with GLOFs produced a nonsteady channel configuration in which old stable channels were abandoned, many new channels were formed, and conveyance capacity changed, best illustrated by the 200 m of delta progradation from the GLOF-affected tributary into the Rio Baker that locally narrowed the Rio Baker channel width from 300 m to 60 m. In total, this analysis demonstrates that GLOFs from distant source lakes can have an outsized impact, both in terms of changing flood characteristics as well as sediment transport, even on the largest river systems.

A synthesis of thermokarst lake water balance in high-latitude regions of North America from isotope tracers

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MacDonald, Lauren A.; Wolfe, Brent B.; Turner, Kevin W.; Anderson, Lesleigh; Arp, Christopher D.; Birks, Jean; Bouchard, Frédéric; Edwards, Thomas W.D.; Farquharson, Nicole; Hall, Roland I.; McDonald, Ian; Narancic, Biljana; Ouimet, Chantal; Pienitz, Reinhard; Tondu, Jana; White, Hilary

2017-01-01

Numerous studies utilizing remote sensing imagery and other methods have documented that thermokarst lakes are undergoing varied hydrological transitions in response to recent climate changes, from surface area expansion to drainage and evaporative desiccation. Here, we provide a synthesis of hydrological conditions for 376 lakes of mainly thermokarst origin across high-latitude North America. We assemble surface water isotope compositions measured during the past decade at five lake-rich landscapes including Arctic Coastal Plain (Alaska), Yukon Flats (Alaska), Old Crow Flats (Yukon), northwestern Hudson Bay Lowlands (Manitoba), and Nunavik (Quebec). These landscapes represent the broad range of thermokarst environments by spanning gradients in meteorological, permafrost, and vegetation conditions. An isotope framework was established based on flux-weighted long-term averages of meteorological conditions for each lake to quantify water balance metrics. The isotope composition of source water and evaporation-to-inflow ratio for each lake were determined, and the results demonstrated a substantial array of regional and subregional diversity of lake hydrological conditions. Controls on lake water balance and how these vary among the five landscapes and with differing environmental drivers are assessed. Findings reveal that lakes in the Hudson Bay Lowlands are most vulnerable to evaporative desiccation, whereas those in Nunavik are most resilient. However, we also identify the complexity in predicting hydrological responses of these thermokarst landscapes to future climate change.

Use of wetlands for water quality improvement under the USEPA Region V Clean Lakes Program

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Landers, Judith C.; Knuth, Barbara A.

1991-03-01

The United States Environmental Protection Agency (USEPA) Region V Clean Lakes Program employs artificial and modified natural wetlands in an effort to improve the water quality of selected lakes. We examined use of wetlands at seven lake sites and evaluated the physical and institutional means by which wetland projects are implemented and managed, relative to USEPA program goals and expert recommendations on the use of wetlands for water quality improvement. Management practices recommended by wetlands experts addressed water level and retention, sheet flow, nutrient removal, chemical treatment, ecological and effectiveness monitoring, and resource enhancement. Institutional characteristics recommended included local monitoring, regulation, and enforcement and shared responsibilities among jurisdictions. Institutional and ecological objectives of the National Clean Lakes Program were met to some degree at every site. Social objectives were achieved to a lesser extent. Wetland protection mechanisms and appropriate institutional decentralization were present at all sites. Optimal management techniques were employed to varying degrees at each site, but most projects lack adequate monitoring to determine adverse ecological impacts and effectiveness of pollutant removal and do not extensively address needs for recreation and wildlife habitat. There is evidence that the wetland projects are contributing to improved lake water quality; however, more emphasis needs to be placed on wetland protection and long-term project evaluation.

Comparison of Public Perception in Desert and Rainy Regions of Chile Regarding the Reuse of Treated Sewage Water

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Daniela Segura

2018-03-01

Full Text Available The objective of this study was to compare the public perception in desert and rainy regions of Chile regarding the reuse of treated sewage water. The methodology of this study consisted of applying a survey to the communities of San Pedro de Atacama (desert region and Hualqui (rainy region to identify attitudes about the reuse of sewage water. The survey was applied directly to men and women, 18 to 90 years old, who were living in the studied communities. The results indicate that inhabitants of San Pedro de Atacama (desert region were aware of the state of their water resources, with 86% being aware that there are water shortages during some part of the year. In contrast, only 55% of residents in Hualqui (rainy region were aware of water shortages. With respect of the reuse of treated sewage water, 47% of respondents in San Pedro de Atacama understood the concept, as compared to 27% in Hualqui. There was more acceptance of using treated sewage water for non-potable purposes than as drinking water.

Distinguishing megathrust from intraplate earthquakes using lacustrine turbidites (Laguna Lo Encañado, Central Chile)

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Van Daele, Maarten; Araya-Cornejo, Cristian; Pille, Thomas; Meyer, Inka; Kempf, Philipp; Moernaut, Jasper; Cisternas, Marco

2017-04-01

One of the main challenges in seismically active regions is differentiating paleo-earthquakes resulting from different fault systems, such as the megathrust versus intraplate faults in subductions settings. Such differentiation is, however, key for hazard assessments based on paleoseismic records. Laguna Lo Encañado (33.7°S; 70.3°W; 2492 m a.s.l.) is located in the Central Chilean Andes, 50 km east of Santiago de Chile, a metropole with about 7,000,000 inhabitants. During the last century the study area experienced 3 large megathrust earthquakes (1906, 1985 and 2010) and 2 intraplate earthquakes (1945 and 1958) (Lomnitz, 1960). While the megathrust earthquakes cause Modified Mercalli Intensities (MMIs) of VI to VII at the lake (Van Daele et al., 2015), the intraplate earthquakes cause peak MMIs up to IX (Sepúlveda et al., 2008). Here we present a turbidite record of Laguna Lo Encañado going back to 1900 AD. While geophysical data (3.5 kHz subbottom seismic profiles and side-scan sonar data) provides a bathymetry and an overview of the sedimentary environment, we study 15 short cores in order to understand the depositional processes resulting in the encountered lacustrine turbidites. All mentioned earthquakes triggered turbidites in the lake, which are all linked to slumps in proximal areas, and are thus resulting from mass wasting of the subaquatic slopes. However, turbidites linked to the intraplate earthquakes are additionally covered by turbidites of a finer-grained, more clastic nature. We link the latter to post-seismic erosion of onshore landslides, which need higher MMIs to be triggered than subaquatic mass movements (Howarth et al., 2014). While intraplate earthquakes can cause MMIs up to IX and higher, megathrust earthquakes do not cause sufficiently high MMIs at the lake to trigger voluminous onshore landslides. Hence, the presence of these post-seismic turbidites allows to distinguish turbidites triggered by intraplate earthquakes from those

Parents willingness to pay for a human papillomavirus vaccine to protect their adolescent daughters. Maule Region, Chile.

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Arcadio A Cerda

2014-01-01

Full Text Available Objective. To determine the willingness to pay of parents of teenage daughters for a vaccine against human papillomavirus in the Maule Region, Chile. Materials and methods. A sample of 386 parents with daughters between 12 and 18 years old, representing the five largest cities of the Region of Maule, socioeconomically stratified. WTP was obtained using the contingent valuation method in double bounded format. Results. Parents are willing to pay an average of US$ 252.71 to vaccinate their daughters against virus, where the price and number of daughters negatively affects the probability of willingness to pay, and family income positively affects the probability. Conclusion. There is a possibility of using shared funding between the government and the parents of potential daughter to be affected by the human papillomavirus to reduce cervical cancer events.

Variability in methane emissions from West Siberia's shallow boreal lakes on a regional scale and its environmental controls

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A. F. Sabrekov

2017-08-01

Full Text Available Small lakes represent an important source of atmospheric CH4 from northern wetlands. However, spatiotemporal variations in flux magnitudes and the lack of knowledge about their main environmental controls contribute large uncertainty into the global CH4 budget. In this study, we measured methane fluxes from small lakes using chambers and bubble traps. Field investigations were carried out in July–August 2014 within the West Siberian middle and southern taiga zones. The average and median of measured methane chamber fluxes were 0.32 and 0.30 mgCH4 m−2 h−1 for middle taiga lakes and 8.6 and 4.1 mgCH4 m−2 h−1 for southern taiga lakes, respectively. Pronounced flux variability was found during measurements on individual lakes, between individual lakes and between zones. To analyze these differences and the influences of environmental controls, we developed a new dynamic process-based model. It shows good performance with emission rates from the southern taiga lakes and poor performance for individual lakes in the middle taiga region. The model shows that, in addition to well-known controls such as temperature, pH and lake depth, there are significant variations in the maximal methane production potential between these climatic zones. In addition, the model shows that variations in gas-filled pore space in lake sediments are capable of controlling the total methane emissions from individual lakes. The CH4 emissions exhibited distinct zonal differences not only in absolute values but also in their probability density functions: the middle taiga lake fluxes were best described by a lognormal distribution while the southern taiga lakes followed a power-law distribution. The latter suggests applicability of self-organized criticality theory for methane emissions from the southern taiga zone, which could help to explain the strong variability within individual lakes.

Huguangyan Maar Lake (SE China): A solid record of atmospheric mercury pollution history in a non-remote region

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Zeng, Yan; Chen, Jingan; Yang, Yongqiong; Wang, Jianxu; Zhu, Zhengjie; Li, Jian

2017-10-01

Mercury is a highly toxic metal that can cause harm to environment and human health. As atmospheric deposition is the main source of total Hg input to aquatic system in remote and pristine regions, almost all the studies on atmospheric Hg pollution history concentrated in these areas, while the studies in non-remote areas are much limited, especially for the long history records. In this study, Huguangyan Maar Lake, an undisturbed lake system at low altitude in China, was selected to reconstruct the atmospheric mercury pollution history. Variation patterns of TOC, Hg and non-residual Sr in the sediment core indicated that, compared to the direct atmospheric Hg deposition, the effect of either Hg scavenging from water column by algae or the catchment inputs of previously deposited Hg on the Hg accumulation in the lake sediment was limited. The sediment Hg content in Huguangyan Lake was mainly controlled by the atmospheric Hg deposition, and thus accurately reflected the atmospheric Hg pollution history. The Hga (Hg content from atmospheric deposition) in Huguangyan Lake presented a comparable variation pattern to that in remote sites. It had the same variation trend as the global atmospheric Hg before 1950 CE, which could be attributed to the Industrial Revolution. After that, it was mainly controlled by Hg emissions from Asian countries. The variation of Hga also indicated that atmospheric Hg deposition accelerated significantly since 2000 CE. This study, along with other investigations in remote sites in China, showed that the sediment Hg in Huguangyan Lake responded to the atmospheric Hg pollution more sensitively than in the alpine regions. It should be noted that, the more intensive acceleration of Hg deposition in Huguangyan Lake may imply that the South of China suffered from much more serious atmospheric Hg pollution than previous studies revealed.

Poverty determinants of acute respiratory infections among Mapuche indigenous peoples in Chile's Ninth Region of Araucania, using GIS and spatial statistics to identify health disparities.

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Rojas, Flavio

2007-07-02

This research concerns Araucanía, often called the Ninth Region, the poorest region of Chile where inequalities are most extreme. Araucanía hasn't enjoyed the economic success Chile achieved when the country returned to democracy in 1990. The Ninth Region also has the largest ethnic Mapuche population, located in rural areas and attached to small agricultural properties. Written and oral histories of diseases have been the most frequently used methods to explore the links between an ancestral population's perception of health conditions and their deprived environments. With census data and hospital records, it is now possible to incorporate statistical data about the links between poverty and disease among ethnic communities and compare results with non-Mapuche population. Hospital discharge records from Health Services North N = 24,126 patients, year 2003, and 7 hospitals), Health Services South (N = 81,780 patients and 25 hospitals); CAS-2/Family records (N = 527,539 individuals, 439 neighborhoods, 32 Comunas). Given the over-dispersion of data and the clustered nature of observations, we used the global Moran's I and General G Gettis-Ord procedures to test spatial dependence. These tests confirmed the clusters of disease and the need to use spatial regression within a General Linear Mixed Model perspective. Health outcomes indicate significantly higher morbidity rates for the Mapuche compared to non-Mapuche in both age groups Mapuches than non-Mapuches for the entire Ninth Region and for all age groups. Mortality caused by respiratory infections is higher among Mapuches than non-Mapuches in all age-groups. A major finding is the link between poverty and respiratory infections. Poverty is significantly associated with respiratory infections in the population of Chile's Ninth Region. High deprivation areas are associated with poverty, and poverty is a predictor of respiratory infections. Mapuches are at higher risk of deaths caused by respiratory infections in

Bacterial Diversity within the Extreme Arid Atacama Desert Soils of the Yungay Region, Chile

Science.gov (United States)

Connon, S. A.; Lester, E. D.; Shafaat, H. S.; Obenhuber, D. C.; Ponce, A.

2006-12-01

Surface and subsurface soil samples analyzed for this study were collected from the hyper-arid Yungay region of the Atacama Desert, Chile. This is the first report of microbial diversity from DNA extracted directly from these extremely desiccated soils. Our data shows that 94% of the 16S rRNA genes cloned from these soils belong to the Actinobacteria phylum. A 24-hour time course series showed a diurnal water activity (aw) cycle that peaked at 0.52 in the early predawn hours, and ranged from 0.08 0.01 during the day. All measured water activity values were below the level required for microbial growth or enzyme activity. Total organic carbon (TOC) levels in this region were just above the limits of detection and ranged from 220 660 μg/g of soil. Phospholipid fatty acid (PLFA) levels indicated cellular biomass ranging from 2 ×105 to 7 ×106 cell equivalents per gram of soil. The culturable counts were low with most samples showing no growth on standard plates of R2A medium; the highest single count was 47 colony forming units (CFU) per gram.

Immigrant health workers in Chile: is there a Latin American "brain drain"?

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Baltica Cabieses

2012-08-01

Full Text Available Most research on the phenomenon of "brain drain" (one-way flow of highly skilled/educated individuals has focused on movement between the least developed and most highly developed countries. Therefore, the significance of patterns of migration to middle-income countries such as those in Latin America is less clear. The aim of this study was to outline key features of international health worker "brain drain" to Chile to promote discussion and further research on this phenomenon as it pertains to the Latin American region. The study compared immigrant health workers living in Chile to both Chilean-born health workers and other immigrants living in Chile using a qualitative nationwide dataset (the results of Chile's 2009 National Socioeconomic Characterization Survey. Demographic, socioeconomic, and health-related variables were included in the analyses, which were weighted by population to obtain nationally representative estimates. In 2009, immigrant health workers represented 2.2% of all health personnel and 2.6% of all resident immigrants in the country. While most immigrant health workers had a universitylevel education, about 25% had only a high school-level education or less. There was no statistically significant difference between the distribution of immigrant health workers' household income and that of Chilean-born health workers. A significantly higher proportion of the immigrant group reported no entitlement to health care provision. While the results of this study do not indicate a significant international health worker "brain drain" to Chile, they do suggest distinctive patterns of migration within the Latin American region. Future studies in Chile could confirm the validity of these results, using a larger sample of immigrant health workers.

Immigrant health workers in Chile: is there a Latin American "brain drain"?

Science.gov (United States)

Cabieses, Baltica; Tunstall, Helena

2012-08-01

Most research on the phenomenon of "brain drain" (one-way flow of highly skilled/educated individuals) has focused on movement between the least developed and most highly developed countries. Therefore, the significance of patterns of migration to middle-income countries such as those in Latin America is less clear. The aim of this study was to outline key features of international health worker "brain drain" to Chile to promote discussion and further research on this phenomenon as it pertains to the Latin American region. The study compared immigrant health workers living in Chile to both Chilean-born health workers and other immigrants living in Chile using a qualitative nationwide dataset (the results of Chile's 2009 National Socioeconomic Characterization Survey). Demographic, socioeconomic, and health-related variables were included in the analyses, which were weighted by population to obtain nationally representative estimates. In 2009, immigrant health workers represented 2.2% of all health personnel and 2.6% of all resident immigrants in the country. While most immigrant health workers had a universitylevel education, about 25% had only a high school-level education or less. There was no statistically significant difference between the distribution of immigrant health workers' household income and that of Chilean-born health workers. A significantly higher proportion of the immigrant group reported no entitlement to health care provision. While the results of this study do not indicate a significant international health worker "brain drain" to Chile, they do suggest distinctive patterns of migration within the Latin American region. Future studies in Chile could confirm the validity of these results, using a larger sample of immigrant health workers.

Exotic plant invasions to the mediterranean region of Chile: causes, history and impacts Invasión de plantas exóticas en la región mediterránea de Chile: causas, historia e impactos

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JAVIER A. FIGUEROA

2004-09-01

Full Text Available We review the literature on patterns, causes, processes and impacts of exotic plants, primarily in the mediterranean region of Chile, considering three major non-independent drivers of the invasion process: (a Availability of exotic species propagules, (b attributes of the local communities in which exotic species establish and through which they will eventually spread out, and (c attributes of exotic species that either facilitate or constraint their spread into new sites. Regarding availability of propagules, central Chile matorral presents the communities with the greatest incidence of naturalized herbs, followed by the sclerophyllous forest and the espinal scrubland in the coastal range. In contrast, north-central communities have lower numbers and proportions of naturalized species of herbs in their seed banks. Availability and persistence of naturalized herbs do not differ between aboveground vegetation and seed bank. Regarding attributes of local communities associated with the establishment and the spread of exotics, grazing regime and land use emerge as the most prominent causes that render them more prone to invasion by exotics. Evidence on the effect of the fire regime is contradictory and native species richness does not seem to be an important factor. Regarding attributes of exotic species, results suggest that naturalized annuals germinate within a wide temperature range, are highly resistant to cold and dry conditions, and show some degree of physiological dormancy. Additionally, naturalized annuals are highly tolerant to poor soils, but are generally intolerant to shade. These general attributes have largely determined the invasion process in the mediterranean region of Chile. Historical data indicate that an important number of exotic species were intentionally introduced, and that the spread of exotic is uncontrolled. It has been demonstrated that arrival time of exotics is of great relevance to understand present day spread of

Testing the Latino paradox in Latin America: a population-based study of Intra-regional immigrants in Chile.

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Cabieses, Baltica; Tunstall, Helena; Pickett, Kate

2013-10-01

Several studies in high-income countries report better health status of immigrants compared to the local population ("healthy migrant" effect), regardless of their socioeconomic deprivation. This is known as the Latino paradox. To test the Latino paradox within Latin America by assessing the health of international immigrants to Chile, most of them from Latin American countries, and comparing them to the Chilean-born. Secondary data analysis of the population-based CASEN survey-2006. Three health outcomes were included: disability, illness/accident, and cancer/chronic condition (dichotomous). Demographics (age, sex, marital status, urban/rural, ethnicity), socioeconomic-status (SES: educational level, employment status and household income per-capita), and material standards (overcrowding, sanitation, housing quality). Crude and adjusted weighted regression models were performed. One percent of Chile's population were immigrants, mainly from other Latin American countries. A "healthy migrant" effect appeared within the total immigrant population: this group had a significantly lower crude prevalence of almost all health indicators than the Chilean-born, which remained after adjusting for various demographic characteristics. However, this effect lost significance when adjusting by SES for most outcomes. The Latino paradox was not observed for international immigrants compared to the local population in Chile. Also, health of immigrants with the longest time of residency showed similar health rates to the Chilean-born. The Latino paradox was not observed in Chile. Protecting low SES immigrants in Chile could have large positive effects in their health at arrival and over time.

Aerosols Observations with a new lidar station in Punta Arenas, Chile

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Barja, Boris; Zamorano, Felix; Ristori, Pablo; Otero, Lidia; Quel, Eduardo; Sugimoto, Nobuo; Shimizu, Atsushi; Santana, Jorge

2018-04-01

A tropospheric lidar system was installed in Punta Arenas, Chile (53.13°S, 70.88°W) in September 2016 under the collaboration project SAVERNET (Chile, Japan and Argentina) to monitor the atmosphere. Statistical analyses of the clouds and aerosols behavior and some cases of dust detected with lidar, at these high southern latitude and cold environment regions during three months (austral spring) are discussed using information from satellite, modelling and solar radiation ground measurements.

Modelling regional response of lakewater chemistry to changes in acidic deposition: the MAGIC model applied to lake surveys in southernmost Norway 1974-1986-1995

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B. J. Cosby

1998-01-01

Full Text Available Two methods for modelling regional responses of lake water quality to changes in acidic deposition in southernmost Norway were examined. Both methods are based upon the MAGIC model but differ in mode of regional application; one uses site-specific while the other uses Monte-Carlo methods for model calibration. The simulations of regional responses from both methods were compared with observed responses based on data from three lake surveys in southernmost Norway conducted in 1974, 1986 and 1995. The regional responses of the two modelling approaches were quite similar and agreed well with the observed regional distributions of lakewater chemistry variables. From 1974 to 1986 the observed data indicated that despite a decline of approximately 10% in sulphate (SO4 deposition, the mean acid neutralizing capacity (ANC of lakes in southernmost Norway declined by approximately 6 μeq l-1. Both modelling approaches simulated no change or a very small decline in mean ANC for that period. From 1986 to 1995 the observed data indicated that, in response to an approximate 40% decline in SO4 deposition, the mean ANC of lakes in southernmost Norway increased by 11-16 μeq l-1. The modelling approaches simulated increases of 9-10 μeq l-1 in mean ANC for the same period. Both simulations and observations indicate that > 65% of lakes in southernmost Norway were acidic in 1974 and 1995. Both simulation methods predict that >65% of the lakes in southernmost Norway will have positive ANC values within 10 years of reductions of SO4 deposition to 20% of 1974 levels. Of the two regionalization methods the site-specific method appears preferable, because whereas the Monte-Carlo method gives results for a region as a whole, the site-specific method also reveals patterns within the region. The maintenance of a one-to-one correspondence between simulated and observed systems means that simulation results can be mapped for a geographically explicit presentation of model

Global Lakes Sentinel Services: Evaluation of Chl-a Trends in Deep Clear Lakes

Science.gov (United States)

Cazzaniga, Ilaria; Giardino, Claudia; Bresciani, Mariano; Poser, Kathrin; Peters, Steef; Hommersom, Annelies; Schenk, Karin; Heege, Thomas; Philipson, Petra; Ruescas, Ana; Bottcher, Martin; Stelzer, Kerstin

2016-08-01

The aim of this study is the analysis of trend in the trophic level evolution in clear deep lakes which, being characterised by good quality state, are important socio- economic resources for their regions. The selected lakes are situated in Europe (Garda, Maggiore, Constance and Vättern), North America (Michigan) and Africa (Malawi and Tanganyika) and cover a range of eco- regions (continental, perialpine, boreal, rift valley) distributed globally.To evaluate trophic level tendency we mainly focused on chlorophyll-a concentrations (chl-a) which is a direct proxy of trophic status. The chl-a concentrations were obtained from 5216 cloud-free MERIS imagery from 2002 to 2012.The 'GLaSS RoIStats tool' available within the GLaSS project was used to extract chl-a in a number of region of interests (ROI) located in pelagic waters as well as some few other stations depending on lakes morphology. For producing the time-series trend, these extracted data were analysed with the Seasonal Kendall test.The results overall show almost stable conditions with a slight increase in concentration for lakes Maggiore, Constance, and the Green Bay of Lake Michigan; a slight decrease for lakes Garda and Tanganyika and absolutely stable conditions for lakes Vättern and Malawi.The results presented in this work show the great capability of MERIS to perform trend tests analysis on trophic status with focus on chl-a concentration. Being chl-a also a key parameter in water quality monitoring plans, this study also supports the managing practices implemented worldwide for using the water of the lakes.

Diversity patterns and composition of native and exotic floras in central Chile

Science.gov (United States)

Figueroa, Javier A.; Teillier, Sebastián; Castro, Sergio A.

2011-03-01

Floristic changes in the Mediterranean region of central Chile brought about by human impact appear to be shared with other climatic regions, although there is a notable absence of empirical studies and available quantitative evidence for the central Chile region. This study examines the cover, richness and composition of native and exotic plant species in a representative area of central Chile. Through floristic characterization of 33 sites sampled using 40 × 40 m plots distributed along transect on which the two farthest sites were separated by 50 km, the floristic richness and cover patterns, as well as the general land use characteristics were evaluated (native matorral, espinal, abandoned farming field, forest plantations, periurban sites, road sites, river bank, and burnt site). We recorded 327 species of plants; 213 species were native and 114 were exotic. The average number of species was heterogeneous in all sites, showing a greater relative native frequency in those sites with a lower level of anthropic intervention. Except for the matorral, the cover of exotic species was greater than that of native species. No relation was found between richness and cover in relation to the different types of land use. The relationship between cover of native and exotic was negative, although for richness did not show relationship. Results show that the exotic species are limited by resources, although they have not completely displaced the native species. The native and exotic floras respond to different spatial distribution patterns, so their presence makes it possible to establish two facts rarely quantified in central Chile: first, that the exotic flora replaces (but does not necessarily displace) the native flora, and second, that at the same time, because of its greater geographic ubiquity and the abundance levels that it achieves, it contributes to the taxonomic and physiognomic homogenization of central Chile.

Chile rural electrification cooperation

Energy Technology Data Exchange (ETDEWEB)

Flowers, L. [National Renewable Energy Lab., Golden, CO (United States)

1997-12-01

The author describes a joint program to use renewables for rural electrification projects in Chile. The initial focus was in a limited part of the country, involving wind mapping, pilot project planning, training, and development of methodologies for comparative evaluations of resources. To this point three wind hybrid systems have been installed in one region, as a part of the regional private utility, and three additional projects are being designed. Additional resource assessment and training is ongoing. The author points out the difficulties in working with utilities, the importance of signed documentation, and the need to look at these programs as long term because of the time involved in introducing such new technologies.

Initial results from the operation of village hybrid systems in Chile

Energy Technology Data Exchange (ETDEWEB)

Holz, R.; Baring-Gould, E.I.; Corbus, D. [and others

1997-08-01

The government of Chile has undertaken a rural electrification program to electrify 75% of the population by the year 2000. Renewable energy is considered within this program, and its application facilitated through a technical cooperation agreement between Chile`s national energy commission (CNE) and the U.S. Department of Energy. In order to introduce isolated mini-grid hybrid wind-energy systems into Chile, three pilot projects were implemented in Region IX. The goal of the pilot systems is to establish renewables as a viable option for rural electrification in the Chilean context. In this paper we report on the first six months of three pilot projects. Presented as background information are brief descriptions of the power systems, data acquisition systems, and the operation and maintenance (O&M) protocols. Analyses of loads, component performance, system operation, and balance of payments for O&M are the primary points presented. Important lessons learned and future plans are also discussed.

Primer "Entrenamiento en Metodologías de Investigación Clínica en Chile" (EMIC-Chile: Fundamentos psicoeducativos First "Training in Clinical Research Methodologies in Chile" (EMIC-Chile: Psychoeducational foundations

Directory of Open Access Journals (Sweden)

B. Cabieses

2010-12-01

Full Text Available EMIC-Chile ("Entrenamiento en Metodologías para la Investigación Clínica en Chile" es un proyecto académico desarrollado durante el año 2008 en Chile para entrenar a profesionales de la salud y disciplinas afines en metodología de investigación clínica, con el objetivo de aumentar la calidad de los proyectos de investigación con fines concursables en nuestro país. El propósito de este artículo es dar a conocer el programa y sus fundamentos teóricos de enseñanza-aprendizaje, que estuvieron en la base de la estructura, metodología, evaluación y sistematización del conocimiento entregado. Para ello, primero se describe el programa, la metodología, la evaluación y el seguimiento. Posteriormente se detallan los aspectos psicoeducativos considerados, con especial énfasis en el aprendizaje social y la educación de adultos. Finalmente, se discute en torno a las posibles consideraciones de este programa para futuras intervenciones educativas en investigación en salud en Chile. Se espera que esta experiencia y sus fundamentos educativos sirvan de motor para futuras iniciativas en el área, a favor de la investigación en salud en Chile.EMIC-Chile ("Entrenamiento en Metodologías para la Investigación Clínica en Chile" is an academic project developed in Chile during 2008 to train health professionals in clinical research. The purpose of this initiative was to improve the quality of research projects that are submitted to apply for public funding. The aim of this article is to describe the psycho-educative theories that supported this training program, its structure, methods and evaluation. Firstly, the program is described in detail. Secondly, psycho-educative theories are described, with special emphasis of social learning theory and education for adults. Finally, implications of EMIC-Chile are stated, in order to improve future research training experiences in Chile. It is expected that this article enhance other research experts

Sanctuaries for lake trout in the Great Lakes

Science.gov (United States)

Stanley, Jon G.; Eshenroder, Randy L.; Hartman, Wilbur L.

1987-01-01

Populations of lake trout, severely depleted in Lake Superior and virtually extirpated from the other Great Lakes because of sea lamprey predation and intense fishing, are now maintained by annual plantings of hatchery-reared fish in Lakes Michigan, Huron, and Ontario and parts of Lake Superior. The extensive coastal areas of the Great Lakes and proximity to large populations resulted in fishing pressure on planted lake trout heavy enough to push annual mortality associated with sport and commercial fisheries well above the critical level needed to reestablish self-sustaining stocks. The interagency, international program for rehabilitating lake trout includes controlling sea lamprey abundance, stocking hatchery-reared lake trout, managing the catch, and establishing sanctuaries where harvest is prohibited. Three lake trout sanctuaries have been established in Lake Michigan: the Fox Island Sanctuary of 121, 500 ha, in the Chippewa-Ottawa Treaty fishing zone in the northern region of the lake; the Milwaukee Reef Sanctuary of 160, 000 ha in midlake, in boundary waters of Michigan and Wisconsin; and Julian's Reef Sanctuary of 6, 500 ha, in Illinois waters. In northern Lake Huron, Drummond Island Sanctuary of 55, 000 ha is two thirds in Indian treaty-ceded waters in Michigan and one third in Ontario waters of Canada. A second sanctuary, Six Fathom Bank-Yankee Reef Sanctuary, in central Lake Huron contains 168, 000 ha. Sanctuary status for the Canadian areas remains to be approved by the Provincial government. In Lake Superior, sanctuaries protect the spawning grounds of Gull Island Shoal (70, 000 ha) and Devils Island Shoal (44, 000 ha) in Wisconsin's Apostle Island area. These seven sanctuaries, established by the several States and agreed upon by the States, Indian tribes, the U.S. Department of the Interior, and the Province of Ontario, contribute toward solving an interjurisdictional fishery problem.

Molecular characterization of endophytic fungi associated with the roots of Chenopodium quinoa inhabiting the Atacama Desert, Chile.

Science.gov (United States)

González-Teuber, M; Vilo, C; Bascuñán-Godoy, L

2017-03-01

Plant roots can be highly colonized by fungal endophytes. This seems to be of particular importance for the survival of plants inhabiting stressful habitats. This study focused on the Identification of the fungal endophytic community associated with the roots of quinoa plants ( Chenopodium quinoa ) growing near the salt lakes of the Atacama Desert, Chile. One hundred endophytic fungi were isolated from healthy quinoa roots, and the internal transcribed spacer (ITS) region was sequenced for phylogenetic and taxonomic analysis. The isolates were classified into eleven genera and 21 distinct operational taxonomic units (OTUs). Despite a relatively high diversity of root endophytic fungi associated with quinoa plants, the fungal community was dominated by only the Ascomycota phyla. In addition, the most abundant genera were Penicillium , Phoma and Fusarium , which are common endophytes reported in plant roots. This study shows that roots of C . quinoa harbor a diverse group of endophytic fungi. Potential roles of these fungi in plant host tolerance to stressful conditions are discussed.

Microbiology of Lonar Lake and other soda lakes

Science.gov (United States)

Paul Antony, Chakkiath; Kumaresan, Deepak; Hunger, Sindy; Drake, Harold L; Murrell, J Colin; Shouche, Yogesh S

2013-01-01

Soda lakes are saline and alkaline ecosystems that are believed to have existed throughout the geological record of Earth. They are widely distributed across the globe, but are highly abundant in terrestrial biomes such as deserts and steppes and in geologically interesting regions such as the East African Rift valley. The unusual geochemistry of these lakes supports the growth of an impressive array of microorganisms that are of ecological and economic importance. Haloalkaliphilic Bacteria and Archaea belonging to all major trophic groups have been described from many soda lakes, including lakes with exceptionally high levels of heavy metals. Lonar Lake is a soda lake that is centered at an unusual meteorite impact structure in the Deccan basalts in India and its key physicochemical and microbiological characteristics are highlighted in this article. The occurrence of diverse functional groups of microbes, such as methanogens, methanotrophs, phototrophs, denitrifiers, sulfur oxidizers, sulfate reducers and syntrophs in soda lakes, suggests that these habitats harbor complex microbial food webs that (a) interconnect various biological cycles via redox coupling and (b) impact on the production and consumption of greenhouse gases. Soda lake microorganisms harbor several biotechnologically relevant enzymes and biomolecules (for example, cellulases, amylases, ectoine) and there is the need to augment bioprospecting efforts in soda lake environments with new integrated approaches. Importantly, some saline and alkaline lake ecosystems around the world need to be protected from anthropogenic pressures that threaten their long-term existence. PMID:23178675

Development of a Regional Glycerol Dialkyl Glycerol Tetraether (GDGT) - Temperature Calibration for Antarctic and sub-Antarctic Lakes

Science.gov (United States)

Roberts, S. J.; Foster, L. C.; Pearson, E. J.; Steve, J.; Hodgson, D.; Saunders, K. M.; Verleyen, E.

2016-12-01

Temperature calibration models based on the relative abundances of sedimentary glycerol dialkyl glycerol tetraethers (GDGTs) have been used to reconstruct past temperatures in both marine and terrestrial environments, but have not been widely applied in high latitude environments. This is mainly because the performance of GDGT-temperature calibrations at lower temperatures and GDGT provenance in many lacustrine settings remains uncertain. To address these issues, we examined surface sediments from 32 Antarctic, sub-Antarctic and Southern Chilean lakes. First, we quantified GDGT compositions present and then investigated modern-day environmental controls on GDGT composition. GDGTs were found in all 32 lakes studied. Branched GDGTs (brGDGTs) were dominant in 31 lakes and statistical analyses showed that their composition was strongly correlated with mean summer air temperature (MSAT) rather than pH, conductivity or water depth. Second, we developed the first regional brGDGT-temperature calibration for Antarctic and sub-Antarctic lakes based on four brGDGT compounds (GDGT-Ib, GDGT-II, GDGT-III and GDGT-IIIb). Of these, GDGT-IIIb proved particularly important in cold lacustrine environments. Our brGDGT-Antarctic temperature calibration dataset has an improved statistical performance at low temperatures compared to previous global calibrations (r2=0.83, RMSE=1.45°C, RMSEP-LOO=1.68°C, n=36 samples), highlighting the importance of basing palaeotemperature reconstructions on regional GDGT-temperature calibrations, especially if specific compounds lead to improved model performance. Finally, we applied the new Antarctic brGDGT-temperature calibration to two key lake records from the Antarctic Peninsula and South Georgia. In both, downcore temperature reconstructions show similarities to known Holocene warm periods, providing proof of concept for the new Antarctic calibration model.

Indicator based sustainability analysis of future energy situation of Santiago de Chile

OpenAIRE

Stelzer, Volker; Quintero, Adriana; Vargas, Luis; Paredes, Gonzalo; Simon, Sonja; Nienhaus, Kristina; Kopfmüller, Jürgen

2014-01-01

Up to now, the Chilean Energy system has fulfilled the energy needs of Santiago de Chile considerably well. However, development trends of the current system impose significant future risks on the energy system. A detailed sustainability analysis of the energy sector of the Metropolitan Region of Santiago de Chile was conducted, using selected energy indicators and a distance-to-target approach. Risks for the sustainable development of the energy sector are detected, such...

Protecting Dark Skies in Chile

Science.gov (United States)

Smith, R. Chris; Sanhueza, Pedro; Phillips, Mark

2018-01-01

Current projections indicate that Chile will host approximately 70% of the astronomical collecting area on Earth by 2030, augmenting the enormous area of ALMA with that of three next-generation optical telescopes: LSST, GMTO, and E-ELT. These cutting-edge facilities represent billions of dollars of investment in the astronomical facilities hosted in Chile. The Chilean government, Chilean astronomical community, and the international observatories in Chile have recognized that these investments are threatened by light pollution, and have formed a strong collaboration to work at managing the threats. We will provide an update on the work being done in Chile, ranging from training municipalities about new lighting regulations to exploring international recognition of the dark sky sites of Northern Chile.

Study of air pollution in Chile using biomonitors

International Nuclear Information System (INIS)

Cortes, E.; Gras, N.; Guzman, G.; Pereira, I.

1999-01-01

A project has been undertaken within the framework of a Co-ordinated Research Programme (CRP) supported by the International Atomic Energy Agency (IAEA) to carry out a long term study on atmospheric air pollution in Chile using biomonitors. The present project aims at the selection of appropriate plants and other indicators for monitoring of air pollution in several cities and rural areas in Chile. Nuclear analytical techniques, in particular neutron activation analysis (NAA) will be used complemented by AAS for the analysis of selected elements and to determine the sources of pollutants and the applicability of biomonitors to study air pollution in large areas, using indicators either naturally grown or artificially introduced to the region under examination. (author)

Análisis exploratorio de los determinantes del ingreso de la ocupación principal a nivel nacional y regional en Chile

Directory of Open Access Journals (Sweden)

Gabriel Leonardo Fuentes Pincheira

2015-11-01

Full Text Available Las enormes diferencias en el nivel de ingreso en Chile son una preocupación latente tanto de las autoridades públicas como de los trabajadores de la nación. Identificar los determinantes que producen la variación del ingreso de la ocupación principal entre un trabajador y otro, resulta atractivo para acercarse al estudio de la problemática de la desigualdad. Con el fin de analizar estos determinantes, se apeló al modelo de regresión de Mincer (1974 y a modo de ajustarlo a la realidad Chilena, se creó una ecuación ampliada integrando las variables género, edad y educación de los padres del individuo. Este trabajo utiliza datos de corte transversal por lo tanto reporta una mirada particular de la realidad nacional, siendo aplicado, además, en regiones. Se obtuvo como resultado que los determinantes con mayor relevancia en Chile son: género, años de escolaridad, experiencia laboral y edad. Income inequality in Chile is a main concern of both, government and workers. To identify the key factors that determine income variation in the main job between workers is appealing in order to approach the inequality problem. Mincer Earning Function (1974 was used to study the key factors of income inequality in Chile. An extended equation including gender, age, and level of education of the worker’s parent’s variables was built up in order to adapt data to Chilean reality. Cross sectional data analysis was conducted to tackle the country’s reality. The results showed that the key factors to income inequality are: genre, level of education, work experience and age.

EVALUATING REGIONAL PREDICTIVE CAPACITY OF A PROCESS-BASED MERCURY EXPOSURE MODEL, REGIONAL-MERCURY CYCLING MODEL (R-MCM), APPLIED TO 91 VERMONT AND NEW HAMPSHIRE LAKES AND PONDS, USA

Science.gov (United States)

Regulatory agencies must develop fish consumption advisories for many lakes and rivers with limited resources. Process-based mathematical models are potentially valuable tools for developing regional fish advisories. The Regional Mercury Cycling model (R-MCM) was specifically d...

Using multi-year reanalysis-derived recharge rates to drive a groundwater model for the Lake Tana region of Blue Nile Basin, Ethiopia

Science.gov (United States)

Dokou, Z.; Kheirabadi, M.; Nikolopoulos, E. I.; Moges, S. A.; Bagtzoglou, A. C.; Anagnostou, E. N.

2017-12-01

Ethiopia's high inter-annual variability in local precipitation has resulted in droughts and floods that stress local communities and lead to economic and food insecurity. Better predictions of water availability can supply farmers and water management authorities with critical guidance, enabling informed water resource allocation and management decisions that will in turn ensure food and water security in the region. The work presented here focuses on the development and calibration of a groundwater model of the Lake Tana region, one of the most important sub-basins of the Blue Nile River Basin. Groundwater recharge, which is the major groundwater source in the area, depends mainly on the seasonality of precipitation and the spatial variation in geology. Given that land based precipitation data are sparse in the region, two approaches for estimating groundwater recharge were used and compared that both utilize global atmospheric reanalysis driven by remote sensing datasets. In the first approach, the reanalysis precipitation dataset (ECMWF reanalysis adjusted based on GPCC) together with evapotranspiration and surface run-off estimates are used to calculate the groundwater recharge component using water budget equations. In the second approach, groundwater recharge estimates (subsurface runoff) are taken directly from a Land Surface model (FLDAS Noah), provided at a monthly time scale and 0.1˚ x 0.1˚ spatial resolution. The reanalysis derived recharge rates in both cases are incorporated into the groundwater model MODFLOW, which in combination with a Lake module that simulates the Lake water budget, offers a unique capability of improving the predictability of groundwater and lake levels in the Lake Tana basin. Model simulations using the two approaches are compared against in-situ observations of groundwater and lake levels. This modeling effort can be further used to explore climate variability effects on groundwater and lake levels and provide guidance to

Hazards of volcanic lakes: analysis of Lakes Quilotoa and Cuicocha, Ecuador

Directory of Open Access Journals (Sweden)

G. Gunkel

2008-01-01

Full Text Available Volcanic lakes within calderas should be viewed as high-risk systems, and an intensive lake monitoring must be carried out to evaluate the hazard of potential limnic or phreatic-magmatic eruptions. In Ecuador, two caldera lakes – Lakes Quilotoa and Cuicocha, located in the high Andean region >3000 a.s.l. – have been the focus of these investigations. Both volcanoes are geologically young or historically active, and have formed large and deep calderas with lakes of 2 to 3 km in diameter, and 248 and 148 m in depth, respectively. In both lakes, visible gas emissions of CO₂ occur, and an accumulation of CO₂ in the deep water body must be taken into account.

Investigations were carried out to evaluate the hazards of these volcanic lakes, and in Lake Cuicocha intensive monitoring was carried out for the evaluation of possible renewed volcanic activities. At Lake Quilotoa, a limnic eruption and diffuse CO₂ degassing at the lake surface are to be expected, while at Lake Cuicocha, an increased risk of a phreatic-magmatic eruption exists.

Predicting Maximum Lake Depth from Surrounding Topography

Science.gov (United States)

Lake volume aids understanding of the physical and ecological dynamics of lakes, yet is often not readily available. The data needed to calculate lake volume (i.e. bathymetry) are usually only collected on a lake by lake basis and are difficult to obtain across broad regions. ...

ESO and Chile: 10 Years of Productive Scientific Collaboration

Science.gov (United States)

2006-06-01

ceremony, along with ambassadors in Chile of ESO members States, and representatives of the Chilean government and the scientific community. To review the impact of the numerous projects financed over the last decade, ESO presented the book "10 Years Exploring the Universe", based on the reports of the beneficiaries of the ESO-Chile fund. Since the beginning, the ESO-Chile fund has granted over 2.5 million euros to finance post-doc and astronomy professors for main Chilean universities, development of research infrastructure, organisation of scientific congresses, workshops for science teachers, and astronomy outreach programmes for the public. In addition to the 400,000 euros given annually by ESO to the ESO-Chile Joint Committee, around 550,000 euros are granted every year to finance regional collaboration programmes, fellowships for students in Chilean universities, and the development of radio astronomy through the ALMA-Chile Committee. In total, apart form the 10 percent of the observing time at all ESO telescopes, ESO contributes annually with 950,000 euros for the promotion of astronomy and scientific culture in Chile. The growth of astronomy and related sciences in Chile in the last years has been outstanding. According to a study by the Chilean Academy of Science in 2005, the number of astronomers has doubled over the last 20 years and there has been an 8-fold increase in the number of scientific publications. It is gratifying to see that 100 percent of the observing time granted by international observatories in Chile is actually used by the national community. The same study stated that astronomy could be the first scientific discipline in Chile with the standards of a developed country, with additional benefits in terms of technological improvement and growth of human resources. The English edition of the book "10 Years Exploring the Universe" is available here. The Spanish edition can be downloaded here.

U-Pb and K-Ar geochronology from the Cerro Empexa Formation, 1st and 2nd Regions, Precordillera, northern Chile

International Nuclear Information System (INIS)

Tomlinson, A.J; Martin, M.W; Blanco, N.; Perez de Arce, C

2001-01-01

The Cerro Empexa Formation (Galli, 1957) is a regionally distributed andesitic volcanic and continental sedimentary unit exposed in the Precordillera of the 1st and 2nd Regions of northern Chile. The formation has generally been considered to lie within the Lower or 'mid' Cretaceous, however, this assignment is based on scant, unreliable geochronologic data. Furthermore, there are conflicting interpretations as to whether the unit predates or postdates the first major Mesozoic shortening event affecting northern Chile. Because of the formation's presumed mid-Cretaceous age and its stratigraphic position over older back-arc sedimentary successions, the unit has been interpreted to represent products of the first eastward jump in the Andean magmatic arc from the arc's initial position in the Cordillera de la Costa (Scheuber and Reutter, 1992). In this paper we present the results of mapping and field observations that indicate exposures previously assigned to the Cerro Empexa Formation include two andesitic volcanic units separated by a major unconformity. The Cerro Empexa Formation proper lies above this unconformity. We also present U-Pb zircon and K-Ar geochronology that indicate the Cerro Empexa Formation is latest Cretaceous in its lower levels, and integrate our data with previously reported 40 Ar/ 39 Ar and fission-track data in the Cerros de Montecristo area (Maksaev, 1990; Maksaev and Zentilli, 1999) to show that 1800±600 m of rocks were deposited within ca. 2.5 m.y (au)

Chile's pipelines - who's out in the cold?

International Nuclear Information System (INIS)

Bellhouse, G.

1998-01-01

There is a battle on in Northern Chile to supply the region with gas and electricity. Two pipelines and a transmission line are being built, but there is insufficient demand to merit the construction of all of these projects. It is widely believed that the first pipeline to be finished will be the overall winner, but the situation is not that simple. A more sensible conclusion could be the merger of the two pipeline projects, rationalising supply of gas to the region. (Author)

La vertebración territorial en regiones de alta especialización: Valle Central de Chile. Alcances para el desarrollo de zonas rezagadas en torno a los recursos naturales

Directory of Open Access Journals (Sweden)

ALBERTO GARCÍA-HUIDOBRO

2010-04-01

Full Text Available Los procesos de reestructuración económica y la apertura de los mercados han generado múltiples y variadas consecuencias sobre nuestros territorios. Quizás para Chile, como para otros países latinoamericanos, uno de los más importantes procesos a nivel regional es el desarrollo de espacios altamente especializados o regiones-commodities. Distintos trabajos académicos señalan que interiormente, en conjunto con áreas de gran competitividad, se están generando áreas rezagadas o alejadas de los dinamismos económicos. Por lo tanto: ¿ En qué ha derivado su modelo de vertebración territorial y su sistema de centros poblados ? ¿Cuáles son las características de estas áreas rezagadas ? Y por ende, ¿cuáles son los desafíos a los cuales se enfrentan? El Valle Central de Chile es una de estas áreas donde se evidencia dicha especialización. Por tanto, analizaremos la estructura física territorial en las que han derivado estas regiones y el papel que cumplen sus centros poblados en los nuevos escenarios. A partir de la caracterización de su vertebración territorial avanzaremos hacia la definición de sus zonas menos favorecidas, e intentaremos generar algunas hipótesis que respondan a sus desafíos y requerimientos futuros.Economic restructuring processes and market opening have generated multiple and varied consequences in our territories. Perhaps for Chile, as with other Latin American countries, one of the most important processes at the regional level is the development of highly specialized spaces or commodity-regions. Different academic work indicates that within these spaces, as well as areas of high competitiveness, there are also backward areas with limited economic dynamism. Consequently: What has happened to the model of a territorial spine and system of population center? What are the characteristics of these backward areas? In addition, what are the challenges to be faced? Chile's Central Valley is one of the areas

Analysis of long-term forest bird monitoring data from national forests of the western Great Lakes Region

Science.gov (United States)

Gerald J. Niemi; Robert W. Howe; Brian R. Sturtevant; Linda R. Parker; Alexis R. Grinde; Nicholas P. Danz; Mark D. Nelson; Edmund J. Zlonis; Nicholas G. Walton; Erin E. Gnass Giese; Sue M. Lietz

2016-01-01

Breeding bird communities in forests of the western Great Lakes region are among the most diverse in North America, but the forest environment in this region has changed dramatically during the past 150 years. To address concerns about loss of biodiversity due to ongoing forest harvesting and to better inform forest planning, researchers have systematically monitored...

Multidrug-Resistant Outbreak-Associated Salmonella Strains in Irrigation Water from the Metropolitan Region, Chile.

Science.gov (United States)

Martínez, M C; Retamal, P; Rojas-Aedo, J F; Fernández, J; Fernández, A; Lapierre, L

2017-06-01

Salmonella enterica (S. enterica) is the main cause of foodborne diseases in the Chilean population. With the aim of characterizing the presence of S. enterica in bodies of water, samples from 40 sources were obtained, including rivers and irrigation canals used by agricultural farms in the most populated regions of Chile. As result, 35 S. enterica isolates belonging to several serotypes were detected, with the highest frequency represented by Typhimurium and Enteritidis. All strains showed phenotypic antimicrobial resistance, and most of them were multiresistant to critically important antimicrobials. In addition, the pulse-field gel electrophoresis analysis using XbaI and BlnI endonucleases showed that seven Salmonella isolates belonging to serotypes Typhimurium, Enteritidis and Infantis had identical pulsotypes to outbreak-associated clinical isolates detected in the Chilean population, suggesting a public health risk of water pollution in this region. Among sampling sites, the higher detection rates were observed in rural than urban and peri-urban areas, suggesting that the animal husbandry might contribute for environmental dispersion of this pathogen. Future efforts should address the characterization of cause-and-effect relationship between water contamination and foodborne disease, including the implementation of surveillance programmes to tackle potential risks for both human and animal populations. © 2016 Blackwell Verlag GmbH.

Ecology, genetic diversity, and phylogeographic structure of andes virus in humans and rodents in Chile.

Science.gov (United States)

Medina, Rafael A; Torres-Perez, Fernando; Galeno, Hector; Navarrete, Maritza; Vial, Pablo A; Palma, R Eduardo; Ferres, Marcela; Cook, Joseph A; Hjelle, Brian

2009-03-01

Andes virus (ANDV) is the predominant etiologic agent of hantavirus cardiopulmonary syndrome (HCPS) in southern South America. In Chile, serologically confirmed human hantavirus infections have occurred throughout a wide latitudinal distribution extending from the regions of Valparaíso (32 to 33 degrees S) to Aysén (46 degrees S) in southern Patagonia. In this study, we found seropositive rodents further north in the Coquimbo region (30 degrees S) in Chile. Rodent seroprevalence was 1.4%, with Oligoryzomys longicaudatus displaying the highest seroprevalence (5.9%), followed by Abrothrix longipilis (1.9%) and other species exhibiting Chile. Phylogenetic analyses showed two major ANDV South (ANDV Sout) clades, congruent with two major Chilean ecoregions, Mediterranean (Chilean matorral [shrubland]) and Valdivian temperate forest. Human and rodent samples grouped according to geographic location. Phylogenetic comparative analyses of portions of S and medium segments (encoding glycoproteins Gn and Gc) from a subset of rodent specimens exhibited similar topologies, corroborating two major ANDV Sout clades in Chile and suggesting that yet unknown factors influence viral gene flow and persistence throughout the two Chilean ecoregions. Genetic algorithms for recombination detection identified recombination events within the S segment. Molecular demographic analyses showed that the virus is undergoing purifying selection and demonstrated a recent exponential growth in the effective number of ANDV Sout infections in Chile that correlates with the increased number of human cases reported. Although we determined virus sequences from four rodent species, our results confirmed O. longicaudatus as the primary ANDV Sout reservoir in Chile. While evidence of geographic differentiation exists, a single cosmopolitan lineage of ANDV Sout remains the sole etiologic agent for HCPS in Chile.

Astro Tourism in Chile | CTIO

Science.gov (United States)

Program PIA Program GO-FAAR Program Other Opportunities Tourism Visits to Tololo Astro tourism in Chile Tourism in Chile Information for travelers Visit Tololo Media Relations News Press Release Publications ‹› You are here CTIO Home » Outreach » Tourism » Astro Tourism in Chile Astro Tourism in

Human leukocyte antigens in indigenous (mapuche) people in a regional renal transplantation program in chile.

Science.gov (United States)

Droguett, M A; Oyarzún, M J; Alruiz, P; Jerez, V; Mezzano, S; Ardiles, L

2005-10-01

An active regional transplantation program established in the southern region of Chile has allowed the incorporation of ethnic minorities particularly Mapuche living in this geographic area in the development of a histocompatibility database. To identify possible differences in the human leukocyte (HLA) antigen distribution in Chilean Mapuche compared with non-Mapuche, we reviewed 442 HLA tissue-typing studies. Seventy-eight of 309 recipients (25%) and 18 of 133 donors (13%) were Mapuche. Among recipients, Mapuche people showed a significantly higher frequency of the HLA antigens, A28, B16, DR4, and DR8, and a lower one for A19, B15, and DR1 (P Mapuche individuals. A particularly higher frequency of the haplotype A28, -B16, -DR4 was also evidenced in Mapuche. Besides, these recipients showed a higher frequency of the allele -DR4 when compared with Mapuche donors. A greater frequency of some histocompatibility antigens in patients with chronic renal disease might be attributed to allelic concentration due to a high index of endogamy, but a possible association with the development of progressive renal disease cannot be ignored, especially when a higher prevalence of DR4 was observed among Mapuche recipients.

Field Survey of the 2015 Ilapel Tsunami in North Central Chile

Science.gov (United States)

Lagos, M.; Fritz, H. M.

2016-12-01

The magnitude Mw 8.3 earthquake in north-central Chile on September 16, 2015 generated a tsunami that rapidly flooded coastal areas. The tsunami impact was concentrated in Coquimbo region, while the regions of Valparaiso and Atacama were also affected. Fortunately, ancestral knowledge from the past tsunamis in the region, as well as tsunami education and evacuation exercises prompted most coastal residents to spontaneously evacuate to high ground after the earthquake. The event caused 11 fatalities: 8 were associated with the tsunami, while 3 were attributed to building collapses caused by the earthquake. The international scientist joined the local effort from September 20 to 26, 2015. The international tsunami survey team (ITST) interviewed numerous eyewitnesses and documented flow depths, runup heights, inundation distances, sediment deposition, damage patterns, performance of the navigation infrastructure and impact on the natural environment. The ITST covered a 500 km stretch of coastline from Caleta Chañaral de Aceituno (28.8° S) south of Huasco down to Llolleo near San Antonio (33.6° S). We surveyed more than 40 locations and recorded more than 100 tsunami and runup heights with differential GPS and integrated laser range finders. The tsunami impact peaked at Caleta Totoral near Punta Aldea with both tsunami and runup heights exceeding 10 m as surveyed on September 22. Runup exceeded 10 m at a second uninhabited location some 15 km south of Caleta Totoral. A significant variation in tsunami impact was observed along the coastlines of central Chile at local and regional scales. The tsunami occurred in the evening hours limiting the availability of eyewitness video footages. Observations from the 2015 Chile tsunami are compared with recent Chilean tsunamis. The tsunami was characterized by rapid arrival within minutes in the nearfield requiring spontaneous self-evacuation as warning messages did not reach some of the hardest hit fishing villages prior to

Post-War Economics. Micro-Level Evidence from the African Great Lakes Region

OpenAIRE

D'Aoust, Olivia

2015-01-01

This thesis starts by arguing that the civil conflicts that erupted in the African Great Lakes are rooted in a continuous pursuit of power, in which ethnic, regional and political identifiers are used by the contenders for power to rally community support. In an introductory chapter, I go back to the colonial era, drawing attention to Burundi and Rwanda, and then describe in more details Burundi's refugee crisis, ex-combatants' demobilization and the 2010 elections, all of which will be addre...

Poverty determinants of acute respiratory infections among Mapuche indigenous peoples in Chile's Ninth Region of Araucania, using GIS and spatial statistics to identify health disparities

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Rojas Flavio

2007-07-01

Full Text Available Abstract Background This research concerns Araucanía, often called the Ninth Region, the poorest region of Chile where inequalities are most extreme. Araucanía hasn't enjoyed the economic success Chile achieved when the country returned to democracy in 1990. The Ninth Region also has the largest ethnic Mapuche population, located in rural areas and attached to small agricultural properties. Written and oral histories of diseases have been the most frequently used methods to explore the links between an ancestral population's perception of health conditions and their deprived environments. With census data and hospital records, it is now possible to incorporate statistical data about the links between poverty and disease among ethnic communities and compare results with non-Mapuche population. Data sources Hospital discharge records from Health Services North N = 24,126 patients, year 2003, and 7 hospitals, Health Services South (N = 81,780 patients and 25 hospitals; CAS-2/Family records (N = 527,539 individuals, 439 neighborhoods, 32 Comunas. Methods Given the over-dispersion of data and the clustered nature of observations, we used the global Moran's I and General G Gettis-Ord procedures to test spatial dependence. These tests confirmed the clusters of disease and the need to use spatial regression within a General Linear Mixed Model perspective. Results Health outcomes indicate significantly higher morbidity rates for the Mapuche compared to non-Mapuche in both age groups Mapuches than non-Mapuches for the entire Ninth Region and for all age groups. Mortality caused by respiratory infections is higher among Mapuches than non-Mapuches in all age-groups. A major finding is the link between poverty and respiratory infections. Conclusion Poverty is significantly associated with respiratory infections in the population of Chile's Ninth Region. High deprivation areas are associated with poverty, and poverty is a predictor of respiratory infections

Biomass size-spectra of macrobenthic communities in the oxygen minimum zone off Chile

Science.gov (United States)

Quiroga, Eduardo; Quiñones, Renato; Palma, Maritza; Sellanes, Javier; Gallardo, Víctor A.; Gerdes, Dieter; Rowe, Gilbert

2005-01-01

Estimates of macrofaunal secondary production and normalized biomass size-spectra (NBSS) were constructed for macrobenthic communities associated with the oxygen minimum zone (OMZ) in four areas of the continental margin off Chile. The presence of low oxygen conditions in the Humboldt Current System (HCS) off Chile was shown to have important effects on the size structure and secondary production of the benthic communities living in this ecosystem. The distribution of normalized biomass by size was linear (log 2-log 2 scale) at all stations. The slope of the NBSS ranged from -0.481 to -0.908. There were significant differences between the slopes of the NBS-spectra from the stations located in the OMZ (slope = -0.837) and those located outside the OMZ (slope = -0.463) ( p oxygen conditions (Chile (6.8 g C m -2 y -1) than off northern Chile (2.02 g C m -2 y -1) and off southern Chile (0.83 g C m -2 y -1). A comparison with other studies suggests that secondary production in terms of carbon equivalents was higher than in other upwelling regions.

Deglaciation, lake levels, and meltwater discharge in the Lake Michigan basin

Science.gov (United States)

Colman, Steven M.; Clark, J.A.; Clayton, L.; Hansel, A.K.; Larsen, C.E.

1994-01-01

The deglacial history of the Lake Michigan basin, including discharge and routing of meltwater, is complex because of the interaction among (1) glacial retreats and re-advances in the basin (2) the timing of occupation and the isostatic adjustment of lake outlets and (3) the depositional and erosional processes that left evidence of past lake levels. In the southern part of the basin, a restricted area little affected by differential isostasy, new studies of onshore and offshore areas allow refinement of a lake-level history that has evolved over 100 years. Important new data include the recognition of two periods of influx of meltwater from Lake Agassiz into the basin and details of the highstands gleaned from sedimentological evidence. Major disagreements still persist concerning the exact timing and lake-level changes associated with the Algonquin phase, approximately 11,000 BP. A wide variety of independent data suggests that the Lake Michigan Lobe was thin, unstable, and subject to rapid advances and retreats. Consequently, lake-level changes were commonly abrupt and stable shorelines were short-lived. The long-held beliefs that the southern part of the basin was stable and separated from deformed northern areas by a hinge-line discontinuity are becoming difficult to maintain. Numerical modeling of the ice-earth system and empirical modeling of shoreline deformation are both consistent with observed shoreline tilting in the north and with the amount and pattern of modern deformation shown by lake-level gauges. New studies of subaerial lacustrine features suggest the presence of deformed shorelines higher than those originally ascribed to the supposed horizontal Glenwood level. Finally, the Lake Michigan region as a whole appears to behave in a similar manner to other areas, both local (other Great Lakes) and regional (U.S. east coast), that have experienced major isostatic changes. Detailed sedimentological and dating studies of field sites and additional

Lake Morphometry for NHD Lakes in the Western Portion of the South Atlantic-Gulf Region 3 HUC

Data.gov (United States)

U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

Lake Morphometry for NHD Lakes in the Northern Portion of the South Atlantic-Gulf Region 3 HUC

Data.gov (United States)

U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

Lake Morphometry for NHD Lakes in the Southern Portion of the South Atlantic-Gulf Region 3 HUC

Data.gov (United States)

U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

Evolution of alkaline lakes - Lake Van case study

Science.gov (United States)

Tillman Meyer, Felix; Viehberg, Finn; Bahroun, Sonya; Wolf, Annabel; Immenhauser, Adrian; Kwiecien, Ola

2017-04-01

Lake Van in Eastern Anatolia (Turkey) is the largest terminal soda lake on Earth. The lake sedimentary profile covers ca. 600 ka (Stockhecke et al. 2014) Based on lithological changes, the presence of freshwater microfossils and close-to-freshwater pH value in the pore water, members of ICDP PALEOVAN concluded that Lake Van might have started as an open lake. Here we show paleontological and geochemical evidence in favour of this idea and constrain the time, when Lake Van likely transformed into a closed lake. Additionally we provide the first conceptual model of how this closure may have happened. Our archives of choice are inorganic and biogenic carbonates, separated by wet sieving. We identified microfossil assemblages (fraction > 125 µm) and performed high-resolution oxygen isotope (delta18O) and elemental (Mg/Ca, Sr/Ca) analyses of the fraction plants growing in the photic zone as food supply. These two aspects point to an increasing salinity in a shallowing lake. The delta18O values of inorganic carbonates are relatively low during the initial phase of Lake Van and increase abruptly (ca. 7‰) after 530 ka BP. At approximately the same time combination of Sr/Ca and Mg/Ca data suggest first occurrence of aragonite. Again, these findings suggest geochemical changes of the lake water concurrent with transition documented by microfossils. Comparison between Lake Van and Lake Ohrid (Lacey et al. 2016) delta18O data, precludes regional climate change (e.g.: increased evaporation) as the main driver of observed changes. With no evidence for increased volcanic or tectonic activity (e.g.: tephra layers, deformation structures, slumping) in the Lake Van sedimentary profile around 530 ka, it seems unlikely that a pyroclastic flow blocked the outflow of the lake. Alternatively, a portion of inflow has been diverged which might have caused a change in the hydrological balance and lake level falling below its outlet. However, as no geomorphological data confirming this

Energy and water in the Great Lakes.

Energy Technology Data Exchange (ETDEWEB)

Tidwell, Vincent Carroll

2011-11-01

The nexus between thermoelectric power production and water use is not uniform across the U.S., but rather differs according to regional physiography, demography, power plant fleet composition, and the transmission network. That is, in some regions water demand for thermoelectric production is relatively small while in other regions it represents the dominate use. The later is the case for the Great Lakes region, which has important implications for the water resources and aquatic ecology of the Great Lakes watershed. This is today, but what about the future? Projected demographic trends, shifting lifestyles, and economic growth coupled with the threat of global climate change and mounting pressure for greater U.S. energy security could have profound effects on the region's energy future. Planning for such an uncertain future is further complicated by the fact that energy and environmental planning and regulatory decisionmaking is largely bifurcated in the region, with environmental and water resource concerns generally taken into account after new energy facilities and technologies have been proposed, or practices are already in place. Based on these confounding needs, the objective of this effort is to develop Great Lakes-specific methods and tools to integrate energy and water resource planning and thereby support the dual goals of smarter energy planning and development, and protection of Great Lakes water resources. Guiding policies for this planning are the Great Lakes and St. Lawrence River Basin Water Resources Compact and the Great Lakes Water Quality Agreement. The desired outcome of integrated energy-water-aquatic resource planning is a more sustainable regional energy mix for the Great Lakes basin ecosystem.

Source apportionment of PM₁₀ and PM₂.₅ in a desert region in northern Chile.

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Jorquera, Héctor; Barraza, Francisco

2013-02-01

Estimating contributions of anthropogenic sources to ambient particulate matter (PM) in desert regions is a challenging issue because wind erosion contributions are ubiquitous, significant and difficult to quantify by using source-oriented, dispersion models. A receptor modeling analysis has been applied to ambient PM(10) and PM(2.5) measured in an industrial zone ~20 km SE of Antofagasta (23.63°S, 70.39°W), a midsize coastal city in northern Chile; the monitoring site is within a desert region that extends from northern Chile to southern Perú. Integrated 24-hour ambient samples of PM(10) and PM(2.5) were taken with Harvard Impactors; samples were analyzed by X Ray Fluorescence, ionic chromatography (NO(3)(-) and SO(4)(=)), atomic absorption (Na(+), K(+)) and thermal optical transmission for elemental and organic carbon determination. Receptor modeling was carried out using Positive Matrix Factorization (US EPA Version 3.0); sources were identified by looking at specific tracers, tracer ratios, local winds and wind trajectories computed from NOAA's HYSPLIT model. For the PM(2.5) fraction, six contributions were found - cement plant, 33.7 ± 1.3%; soil dust, 22.4 ± 1.6%; sulfates, 17.8 ± 1.7%; mineral stockpiles and brine plant, 12.4 ± 1.2%; Antofagasta, 8.5 ± 1.3% and copper smelter, 5.3 ± 0.8%. For the PM(10) fraction five sources were identified - cement plant, 38.2 ± 1.5%; soil dust, 31.2 ± 2.3%; mineral stockpiles and brine plant, 12.7 ± 1.7%; copper smelter, 11.5 ± 1.6% and marine aerosol, 6.5 ± 2.4%. Therefore local sources contribute to ambient PM concentrations more than distant sources (Antofagasta, marine aerosol) do. Soil dust is enriched with deposition of marine aerosol and calcium, sulfates and heavy metals from surrounding industrial activities. The mean contribution of suspended soil dust to PM(10) is 50 μg/m(3) and the peak daily value is 104 μg/m(3). For the PM(2.5) fraction, suspended soil dust contributes with an average of 9.3 �

Spatial and temporal patterns in trace element deposition to lakes in the Athabasca oil sands region (Alberta, Canada)

Science.gov (United States)

Cooke, Colin A.; Kirk, Jane L.; Muir, Derek C. G.; Wiklund, Johan A.; Wang, Xiaowa; Gleason, Amber; Evans, Marlene S.

2017-12-01

The mining and processing of the Athabasca oil sands (Alberta, Canada) has been occurring for decades; however, a lack of consistent regional monitoring has obscured the long-term environmental impact. Here, we present sediment core results to reconstruct spatial and temporal patterns in trace element deposition to lakes in the Athabasca oil sands region. Early mining operations (during the 1970s and 1980s) led to elevated V and Pb inputs to lakes located quality guidelines, and no spatial or temporal trends were observed in the frequency of guideline exceedence. Our results demonstrate that early mining efforts had an even greater impact on trace element cycling than has been appreciated previously, placing recent monitoring efforts in a critical long-term context.

Predicting the locations of naturally fishless lakes

Science.gov (United States)

Schilling, Emily Gaenzle; Loftin, C.S.; Degoosh, K.E.; Huryn, Alexander D.; Webster, K.E.

2008-01-01

1. Fish have been introduced into many previously fishless lakes throughout North America over the past 100+ years. It is difficult to determine the historical distribution of fishless lakes, however, because these introductions have not always been well-documented. 2. Due to its glacial history and low human population density, the state of Maine (U.S.A.) may host the greatest number of naturally fishless lakes in the northeastern United States. However, less than one-quarter of Maine's 6000+ lakes have been surveyed for fish presence, and no accurate assessments of either the historical or current abundance and distribution of fishless lakes exist. 3. We developed methods to assess the abundance and distribution of Maine's naturally fishless lakes (0.6-10.1 ha). We hypothesized that the historical distribution of fishless lakes across a landscape is controlled by geomorphic and geographic conditions. 4. We used ArcGIS to identify landscape-scale geomorphic and geographic factors (e.g. connectivity, surrounding slope) correlated with fish absence in two geomorphic regions of Maine - the western and interior mountains and the eastern lowlands and foothills. By using readily available geographic information systems data our method was not limited to field-visited sites. We estimated the likelihood that a particular lake is fishless with a stepwise logistic regression model developed for each region. 5. The absence of fish from western lakes is related to altitude (+), minimum percent slope in the 500 m buffer (+), maximum percent slope in the 500 m buffer (+) and percent cover of herbaceous-emergent wetland in 1000 m buffer (-). The absence of fish from eastern lakes is related to the lack of a stream within 50 m of the lake. 6. The models predict that a total of 4% (131) of study lakes in the two regions were historically fishless, with the eastern region hosting a greater proportion than the western region. 7. We verified the model predictions with two

Applications of the Regional Atmospheric Modeling System (RAMS) to provide input to photochemical grid models for the Lake Michigan Ozone Study (LMOS)

Energy Technology Data Exchange (ETDEWEB)

Lyons, W.A.; Tremback, C.J.; Pielke, R.A. [ASTeR, Inc., Ft. Collins, CO (United States); Eastman, J.L. [Colorado State Univ., Ft. Collins, CO (United States)

1994-12-31

In spite of stringent emission controls, numerous exceedances of the US ozone air quality standard have continued in the Lake Michigan region, especially during the very hot summers of 1987 and 1988. Analyses revealed that exceedances of the 120 PPB hourly standard were 400% more likely at monitors located within 20 km of the lakeshore. While the role of Lake Michigan in exacerbating regional air quality problems has been investigated for almost 20 years, the relative impacts of various phenomena upon regional photochemical air quality have yet to be quantified. In order to design a defensible regional emission control policy, LMOS sponsored the development of a comprehensive regional photochemical modeling system. This is comprised of an emission model, an advanced regional photochemical model, and a prognostic meteorological model.

Investigation of the dispersion of airborne pollutants in the Upper Rhine and Lake Constance region

International Nuclear Information System (INIS)

Fiedler, F.; Adrian, G.; Kohler, M.

1991-01-01

The aim of the project is to calculate the regional flow and propagation conditions using the expensive three-dimensional meteorological model, the ''Karlsruher Atmosphaerisches Mesoskaliges Modell'' (KAMM) in order to derive the immission and the deposition of the conducting substance of pollutant matter, i.e., sulphur dioxide. In this report, calculations of the flowing field are described for the region Upper Rhine - Lake of Constance''. In the last part, the concentration fields for SO 2 are calculated for the region for typical large-area atmospheric conditions with disclosure of sources. An appraising discussion of the results concludes this work. (orig.) [de

Estado de la investigacion en enfermería IX región de la Araucania, Temuco, Chile 2002 State of the research in nursing IX th region of the Araucania, Temuco, Chile 2002

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Edith Elina Rivas Riveros

2005-09-01

, situation that should be based in the evidence. The purpose of the investigation was to identify through a descriptive, exploratory study, correlation the state of the investigation in Infirmary in the IX Region of the Araucania, Chile. The specific objectives were: to analyze the conditions in that you development the improvement of the nurses in the IX Region and to contribute to identify the investigation lines. The study picks up the characteristics in that the improvement of the nurses is developed in the IX Region, Chile: Degree, Magíster and Doctorates until the year 2002 One concludes that as for approaches the positivist prevails, the motivation of the Nurses to there be perfecting in programs of postdegree this one given fundamentally by personal development and to help to improve the profession; those who realize studies of postdegrees get out of a jam themselves in teaching in institutes and / or universities and the subject matter of the investigations is fundamentally orientated towards the education of nursing.

[Food-related lifestyles and eating habits inside and outside the home in the Metropolitan Region of Santiago, Chile].

Science.gov (United States)

Schnettler, Berta; Peña, Juan Pablo; Mora, Marcos; Miranda, Horacio; Sepúlveda, José; Denegri, Marianela; Lobos, Germán

2013-01-01

To distinguish consumer typologies on the basis of their food-related lifestyle in the principal municipalities of the Metropolitan Region of Santiago, Chile, and to characterize these according to their food consumption habits inside and outside the home, sociodemographic characteristics and their level of satisfaction with food-related life. A structured questionnaire was administered to a sample of 951 people in the principal municipalities of the Metropolitan Region of Santiago (more than 100,000 inhabitants). The instrument for collecting data included an adaptation of the food-related life (FRL) questionnaire and the satisfaction with food-related life (SWFL) scale. The food consumption habits inside and outside the home were asked about as well as sociodemographic classification variables of those surveyed. Using a cluster analysis, five typologies were distinguished with significant differences in the five components obtained from the FRL with a factorial analysis of the principal components. The typologies presented a different gender, age and socioeconomic level profile and differed in the scores obtained on the SWFL. They differed in the frequency with which the person has lunch, tea ("once" in Chile) and dinner at home. With respect to the meals outside the home, the typologies were distinguished according to the frequency of meals in restaurants, fast food outlets and in the purchase of prepared food. A lifestyle where eating is related to low involvement and enjoyment of food is associated with a person's higher socioeconomic level and lower age. Additionally, a greater frequency of meals in restaurants and the purchase of prepared food combined with a lower frequency of meals at home is associated with unhealthy eating habits of little benefit to the person, which might have a bearing on a lower level of food-related life satisfaction. Copyright © AULA MEDICA EDICIONES 2013. Published by AULA MEDICA. All rights reserved.

U.S. Forest Service Region 1 Lake Chemistry, NADP, and IMPROVE air quality data analysis

Science.gov (United States)

Jill Grenon; Mark Story

2009-01-01

This report was developed to address the need for comprehensive analysis of U.S. Forest Service (USFS) Region 1 air quality monitoring data. The monitoring data includes Phase 3 (long-term data) lakes, National Atmospheric Deposition Program (NADP), and Interagency Monitoring of Protected Visual Environments (IMPROVE). Annual and seasonal data for the periods of record...

Modernitet og forbrugskultur i Chile

DEFF Research Database (Denmark)

Cristoffanini, Pablo Rolando

2012-01-01

I de sidste årtier er Chile blevet et egentligt forbrugersamfund. Udbredelsen af forbrugskulturen og forbrugerismen er centrale fænomener i chilenernes dagligliv og har nået et omfang, som har konsekvenser for de borgere, der ikke kan deltage fuldt ud heri, noget som er typisk for et samfund med en...... ujævn økonomisk udvikling og med store sociale forskelle. Denne proces er ikke et produkt af en stille, fredelig og naturlig samfundsudvikling, således som magteliten og de toneangivende intellektuelle i Chile har fremstillet det. Som jeg vil vise, er skabelsen af et egentlig forbrugssamfund knyttet til...... til i dag. Ifølge disse er Chile blevet et moderne samfund netop i kraft af, at Chile er et ægte forbrugersamfund med alt, hvad dette indebærer, såvel materielt som symbolsk. For det tredje er billedet af Chile som en ”supermoderne” nation i den latinamerikanske kontekst en udbredt forestilling hos...

conelchilenoresistentearte, Solidaridad: Chile Vive, una Exposición en España contra el Chile Dictatorial withthechileanresistantart, Solidarity: Chile Vive, an Exposition in Spain against the Dictatorial Chile

Directory of Open Access Journals (Sweden)

Francisco Godoy

2010-12-01

Full Text Available En 1987 se realiza en Madrid Chile Vive, megaexposición que incluye diferentes manifestaciones artísticas para dar cuenta de la vitalidad cultural de Chile en dictadura. El ensayo, partiendo de una discusión conceptual sobre el problema de la exposición de arte latinoamericano en el extranjero, analiza la configuración de esta exposición, centrándose en las artes visuales como alineación unitaria de un discurso político de país, además de examinar su repercusión en la prensa española de la época. Por otro lado, reflexiona sobre las inclusiones y exclusiones de artistas y las proyecciones de Chile Vive en el problema de la exposición del arte chileno en el extranjero, particularmente el de un periodo tan complejo como el producido durante la dictadura militar.In 1987, Chile Vive, a mega-exhibition that included different artistic expressions, was performed in Madrid to inform people about the cultural vitality of Chile during their dictatorship. This essay will focus on a conceptual discussion about the problem of Latin American art exhibitions abroad. It will analyze the configuration of the mentioned exhibition, focusing on visual arts as a unitary alignment of a political discourse of nation. The text will also examine the repercussion in the Media of Spain in that period of time. On the other hand, the article will develop some thoughts on the artists incorporations, exclusions and projections of Chile Vive, focusing on why the exhibition of Chilean art abroad might be problematic, particularly the ones that belongs to this complex period of time; the military dictatorship.

Regional environmental change and human activity over the past hundred years recorded in the sedimentary record of Lake Qinghai, China.

Science.gov (United States)

Sha, ZhanJiang; Wang, Qiugui; Wang, Jinlong; Du, Jinzhou; Hu, Jufang; Ma, Yujun; Kong, Fancui; Wang, Zhuan

2017-04-01

Environmental change and human activity can be recorded in sediment cores in aquatic systems such as lakes. Information from such records may be useful for environmental governance in the future. Six sediment cores were collected from Lake Qinghai, China and its sublakes during 2012 and 2013. Measurements of sediment grain-size fractions indicate that sedimentation in the north and southwest of Lake Qinghai is dominated by river input, whereas that in Lake Gahai and Lake Erhai is dominated by dunes. The sedimentation rates in Lake Qinghai were calculated to be 0.101-0.159 cm/y, similar to the rates in other lakes on the Qinghai-Tibetan Plateau. Using these data and sedimentation rates from the literature, we compiled the spatial distribution of sedimentation rates. Higher values were obtained in the three main areas of Lake Qinghai: two in river estuaries and one close to sand dunes. Lower values were measured in the center and south of the lake. Measurements of total organic carbon (TOC), total nitrogen (TN), phosphorus concentrations, and TOC/TN ratios in three cores (QH01, QH02, and Z04) revealed four horizons corresponding to times of increased human activity. These anthropogenic events were (1) the development of large areas of cropland in the Lake Qinghai watershed in 1960, (2) the beginning of nationwide fertilizer use and increases in cropland area in the lake watershed after 1970, (3) the implementation of the national program "Grain to Green," and (4) the rapid increase in the tourism industry from 2000. Profiles of Rb, Sr concentrations, the Rb/Sr ratio, and grain-size fraction in core Z04 indicate that the climate has become drier over the past 100 years. Therefore, we suggest that lake sediments such as those in Lake Qinghai are useful media for high-resolution studies of regional environmental change and human activity.

Climate and climate variability of the wind power resources in the Great Lakes region of the United States

Science.gov (United States)

X. Li; S. Zhong; X. Bian; W.E. Heilman

2010-01-01

The climate and climate variability of low-level winds over the Great Lakes region of the United States is examined using 30 year (1979-2008) wind records from the recently released North American Regional Reanalysis (NARR), a three-dimensional, high-spatial and temporal resolution, and dynamically consistent climate data set. The analyses focus on spatial distribution...

Intense magmatic degassing through the lake of Copahue volcano, 2013-2014

Science.gov (United States)

Tamburello, G.; Agusto, M.; Caselli, A.; Tassi, F.; Vaselli, O.; Calabrese, S.; Rouwet, D.; Capaccioni, B.; Di Napoli, R.; Cardellini, C.; Chiodini, G.; Bitetto, M.; Brusca, L.; Bellomo, S.; Aiuppa, A.

2015-09-01

Here we report on the first assessment of volatile fluxes from the hyperacid crater lake hosted within the summit crater of Copahue, a very active volcano on the Argentina-Chile border. Our observations were performed using a variety of in situ and remote sensing techniques during field campaigns in March 2013, when the crater hosted an active fumarole field, and in March 2014, when an acidic volcanic lake covered the fumarole field. In the latter campaign, we found that 566 to 1373 t d-1 of SO2 were being emitted from the lake in a plume that appeared largely invisible. This, combined with our derived bulk plume composition, was converted into flux of other volcanic species (H2O ~ 10989 t d-1, CO2 ~ 638 t d-1, HCl ~ 66 t d-1, H2 ~ 3.3 t d-1, and HBr ~ 0.05 t d-1). These levels of degassing, comparable to those seen at many open-vent degassing arc volcanoes, were surprisingly high for a volcano hosting a crater lake. Copahue's unusual degassing regime was also confirmed by the chemical composition of the plume that, although issuing from a hot (65°C) lake, preserves a close-to-magmatic signature. EQ3/6 models of gas-water-rock interaction in the lake were able to match observed compositions and demonstrated that magmatic gases emitted to the atmosphere were virtually unaffected by scrubbing of soluble (S and Cl) species. Finally, the derived large H2O flux (10,988 t d-1) suggested a mechanism in which magmatic gas stripping drove enhanced lake water evaporation, a process likely common to many degassing volcanic lakes worldwide.

First parasitological study of the African clawed frog (Xenopus laevis, Amphibia in Chile

Directory of Open Access Journals (Sweden)

Cristóbal Castillo

Full Text Available Abstract Introduced species can arrive into new territories with parasites; however, these species are expected to face lower parasite richness than in their original regions. Both introduced hosts and parasites can affect native fauna. Since their release into the wild in Chile following laboratory use, Xenopus laevis Daudin, 1802 has widely spread throughout central Chile. The only pathogen described on the host is the fungus Batrachochytrium dendrobatidis Longcore, Pessier, Nichols, 1999; thus, this is the first parasitological study of this species in Chile. In 10 localities in central Chile, 179 specimens of X. laevis were captured and examined for parasites in the gastrointestinal tube, cavities, lungs, liver, and skin. Only nine specimens of the genus Contracaecum Railliet, Henry, 1912 were found in six specimens of X. laevis from a private dam in La Patagua. It is likely that these parasites originated from species of native birds. This is the first record of Contracaecum sp. in Chilean amphibians.

Intense Seismic Activity at Chiles and Cerro Negro Volcanoes on the Colombia-Ecuador Border

Science.gov (United States)

Torres, R. A.; Cadena, O.; Gomez, D.; Ruiz, M. C.; Prejean, S. G.; Lyons, J. J.; White, R. A.

2015-12-01

The region of Chiles and Cerro Negro volcanoes, located on the Colombian-Ecuadorian border, has experienced an ongoing seismic swarm beginning in Aug. 2013. Based on concern for local residents and authorities, a cooperative broadband monitoring network was installed by the Servicio Geológico Colombiano in Colombia and the Instituto Geofísico of the Escuela Politécnica Nacional in Ecuador. Since November 2013 more than 538,000 earthquakes were recorded; although since May 2015 the seismicity has decreased significantly to an average of 70 events per day. Three large earthquake swarms with increasing energy occurred in Aug.-Oct. 2013, March-May 2014, and Sept.-Dec. 2014. By the end of 2014, roughly 400 earthquakes greater than M 3 had occurred with a maximum rate of 8000 earthquakes per day. The largest earthquake was a 5.6 ML on Oct. 20, 2014. This event produced an InSAR coseismic deformation of ~23 cm (S. Ebmeier, personal communication). Most events are typical brittle failure volcano-tectonic (VT) earthquakes that are located in a cluster beneath the southern flank of Chiles volcano, with depths between 1.5 and 10 km. Although the great majority of earthquakes are VT, some low-frequency (LF, ~0.5 Hz) and very-low-frequency (VLF) events have occurred. Particle motion analysis suggests that the VLF source migrated with time. While a VLF on Oct. 15, 2014 was located south of Chiles volcano, near the InSAR source, the VLF registered on Feb. 14, 2015 was likely located very close to Chiles Volcano. We infer that magma intrusion and resulting fluid exsolution at depths greater than 5 km are driving seismicity in the Chiles-Cerro Negro region. However earthquakes are failing in a manner consistent with regional tectonics. Relative relocations reveal a structure consistent with mapped regional faults. Thus seismicity is likely controlled by an interaction of magmatic and tectonic processes. Because the regional stress field is highly compressional and the volcanoes

Detection and phylogenetic analysis of infectious pancreatic necrosis virus in Chile.

Science.gov (United States)

Tapia, D; Eissler, Y; Torres, P; Jorquera, E; Espinoza, J C; Kuznar, J

2015-10-27

Infectious pancreatic necrosis virus (IPNV) is the etiological agent of a highly contagious disease that is endemic to salmon farming in Chile and causes great economic losses to the industry. Here we compared different diagnostic methods to detect IPNV in field samples, including 3 real-time reverse transcription PCR (qRT-PCR) assays, cell culture isolation, and indirect fluorescent antibody test (IFAT). Additionally, we performed a phylogenetic analysis to investigate the genogroups prevailing in Chile, as well as their geographic distribution and virulence. The 3 qRT-PCR assays used primers that targeted regions of the VP2 and VP1 genes of the virus and were tested in 46 samples, presenting a fair agreement within their results. All samples were positive for at least 2 of the qRT-PCR assays, 29 were positive for cell culture, and 23 for IFAT, showing less sensitivity for these latter 2 methods. For the phylogenetic analysis, portions of 1180 and 523 bp of the VP2 region of segment A were amplified by RT-PCR, sequenced and compared with sequences from reference strains and from isolates reported by previous studies carried out in Chile. Most of the sequenced isolates belonged to genogroup 5 (European origin), and 5 were classified within genogroup 1 (American origin). Chilean isolates formed clusters within each of the genogroups found, evidencing a clear differentiation from the reference strains. To our knowledge, this is the most extensive study completed for IPNV in Chile, covering isolates from sea- and freshwater salmon farms and showing a high prevalence of this virus in the country.

[Brucellosis in Chile: Description of a series of 13 cases].

Science.gov (United States)

Olivares, Roberto; Vidal, Pamela; Sotomayor, Camila; Norambuena, Mackarenna; Luppi, Mario; Silva, Francisco; Cifuentes, Marcela

2017-06-01

Brucellosis is a zoonosis caused by Brucella spp. It may be acquired by consuming unpasteurized dairy products. Brucellosis has a low incidence in Chile, thus, we have a scarce data. To report and to characterize the first series of clinical cases of adult patients diagnosed with brucellosis in Chile. We describe a series of 13 clinical cases in patients diagnosed between 2000 and 2016 in three different centers in the Metropolitan Region, Chile. A retrospective analysis was performed on clinical presentation, laboratory, antibiotic treatment, morbidity and mortality. The mean age was 50 years old. Eight cases had a record of consumption of unpasteurized dairy products. The most frequently reported complaints were fever. The most frequent focal point involved was the spine. Only one patient had a positive blood culture, while the diagnosis was made using serological techniques in the other part of the group. The most indicated antibiotic regimens were doxycycline-rifampicin and doxycycline-gentamicin. The hospital stay was 20 days approximately as an average. Clinical cure was achieved in all cases. Brucellosis is an infrequent zoonosis in Chile, and it produces a nonspecific clinical picture, so it is necessary to have high suspicion to make the diagnosis based in the antecedent of consumption of unpasteurized dairy or raw meat.

Hydrothermal Exploration at the Chile Triple Junction - ABE's last adventure?

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German, C. R.; Shank, T. M.; Lilley, M. D.; Lupton, J. E.; Blackman, D. K.; Brown, K. M.; Baumberger, T.; Früh-Green, G.; Greene, R.; Saito, M. A.; Sylva, S.; Nakamura, K.; Stanway, J.; Yoerger, D. R.; Levin, L. A.; Thurber, A. R.; Sellanes, J.; Mella, M.; Muñoz, J.; Diaz-Naveas, J. L.; Inspire Science Team

2010-12-01

In February and March 2010 we conducted preliminary exploration for hydrothermal plume signals along the East Chile Rise where it intersects the continental margin at the Chile Triple Junction (CTJ). This work was conducted as one component of our larger NOAA-OE funded INSPIRE project (Investigation of South Pacific Reducing Environments) aboard RV Melville cruise MV 1003 (PI: Andrew Thurber, Scripps) with all shiptime funded through an award of the State of California to Andrew Thurber and his co-PI's. Additional support came from the Census of Marine Life (ChEss and CoMarge projects). At sea, we conducted a series of CTD-rosette and ABE autonomous underwater vehicle operations to prospect for and determine the nature of any seafloor venting at, or adjacent to, the point where the the East Chile Rise subducts beneath the continental margin. Evidence from in situ sensing (optical backscatter, Eh) and water column analyses of dissolved CH4, δ3He and TDFe/TDMn concentrations document the presence of two discrete sites of venting, one right at the triple junction and the other a further 10km along axis, north of the Triple Junction, but still within the southernmost segment of the East Chile Rise. From an intercomparison of the abundance of different chemical signals we can intercompare likely characteristics of these differet source sites and also differentiate between them and the high methane concentrations released from cold seep sites further north along the Chile Margin, both with the CTJ region and also at the Concepcion Methane Seep Area (CMSA). This multi-disciplinary and international collaboration - involving scientists from Chile, the USA, Europe and Japan - can serve as an excellent and exciting launchpoint for wide-ranging future investigations of the Chile Triple Junction area - the only place on Earth where an oceanic spreading center is being actively subducted beneath a continent and also the only place on Earth where all known forms of deep

Oropharyngeal cancer mortality according to the human development index in the Metropolitan Region of Chile, 2002-2014.

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Vicente Livacic

2018-01-01

Full Text Available To determine mortality rates for oropharyngeal cancer according to the Human Development Index (HDI per district in the Metropolitan Region (RM, Santiago, Chile, between 2002 and 2014. Materials and Methods: An ecological study was carried out. The sample corresponded to individuals over 45 years, from the Metropolitan Region, with oropharyngeal cancer as cause of death, as registered in the Chilean National Institute of Statistics (INE. The HDI was classified into three categories: “medium” (8 districts, “high” (18 districts and “very high” (25 districts. The crude and adjusted mortality rates were calculated for each year and period. Results: The oropharyngeal cancer adjusted mortality rate for the chosen period was 3.98 deaths per 100,000 inhabitants. The specific mortality rate from oropharyngeal cancer in the “medium” HDI category was 4.01; in the “high” DHI category, 4.42; and in the “very high” HDI category, 3.79. Conclusion: Mortality from oropharyngeal cancer was higher in the “medium” HDI category between 2002 and 2014.

Resilience and Restoration of Lakes

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Stephen R. Carpenter

1997-06-01

Full Text Available Lake water quality and ecosystem services are normally maintained by several feedbacks. Among these are nutrient retention and humic production by wetlands, nutrient retention and woody habitat production by riparian forests, food web structures that cha nnel phosphorus to consumers rather than phytoplankton, and biogeochemical mechanisms that inhibit phosphorus recycling from sediments. In degraded lakes, these resilience mechanisms are replaced by new ones that connect lakes to larger, regional economi c and social systems. New controls that maintain degraded lakes include runoff from agricultural and urban areas, absence of wetlands and riparian forests, and changes in lake food webs and biogeochemistry that channel phosphorus to blooms of nuisance al gae. Economic analyses show that degraded lakes are significantly less valuable than normal lakes. Because of this difference in value, the economic benefits of restoring lakes could be used to create incentives for lake restoration.

The Bulimulidae (Mollusca: Pulmonata) from the Región de Atacama, northern Chile.

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Araya, Juan Francisco

2015-01-01

The bulimulid genus Bostryx Troschel, 1847 is the most species-rich genus of land snails found in Chile, with the majority of its species found only in the northern part of the country, usually in arid coastal zones. This genus has been sparsely studied in Chile and there is little information on their distribution, diversity or ecology. Here, for the first time, a formal analysis of the diversity of bulimulids in the Región de Atacama, northern Chile, is reported. Of the seventeen species recorded for the area, most of them were efectively found in the field collections and one record was based on literature. Five taxa are described as new: Bostryx ancavilorum sp. nov., Bostryx breurei sp. nov., Bostryx calderaensis sp. nov., Bostryx ireneae sp. nov. and Bostryx valdovinosi sp. nov., and the known geographic distribution of seven species is extended. Results reveal that the Región de Atacama is the richest region in terrestrial snails in Chile, after the Juan Fernández Archipelago. All of the terrestrial molluscan species occurring in the area are endemic to Chile, most of them with restricted geographic distributions along the coastal zones, and none of them are currently protected by law. Further sampling in northern Chile will probably reveal more snail species to be discovered and described.

University Support in the Development of Regional Entrepreneurial Activity: An Exploratory Study from Chile

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Carlos Poblete

2013-01-01

Full Text Available La literatura teórica ha estudiado los potenciales beneficios de la interacción entre universidades y emprendedores y existe cierta evidencia empírica que soporta la influencia positiva de la educación para el emprendimiento en la posterior propensión a emprender. El propósito de este artículo es estudiar si la educación específica para la creación de empresas brindada por las universidades se refleja en la actividad emprendedora a nivel regional. Replicando la metodología utilizada por Coduras, Urban, Rojas y Martínez (2008 en España, comparamos de forma exploratoria el caso en Chile usando la base de datos del Global Entrepreneurship Monitor (GEM. Los principales resultados indican que hay baja interacción entre emprendedores y universidades, y no hay impacto suficiente para afectar significativamente la actividad emprendedora. Así como contar con educación para el emprendimiento en la universidad no aumentaría la probabilidad de tener intenciones de emprender.

Retrospective study of histological types of esophageal cancer prevalent in the Metropolitan Region of Santiago, Chile

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Andrés Torrealba Bustos

2010-11-01

Full Text Available This study tries to determine the statistical relation between the most frequent histological types of oesophageal carcinoma in the Metropolitan region of Santiago, Chile. For it there were obtained clinical samples of different laboratories of Pathological Anatomy of the Metropolitan region corresponding to the south and east sector of Santiago, gathering a total of 348 cases, which were diagnosed by means of endoscopic biopsy, using as parameters the morphologic characteristics of neoplastic tissue evaluated by light microscopy with hematoxylin-eosin dye. The obtained information was submitted to a model of logistic multiple regression, in order to determine the associations between the most frequent histological types of oesophageal cancer (adenocarcinoma and squamous carcinoma, topographic location compromised to the moment of the diagnosis, age and sex of the patients in study. The proportion between the histological types of cancer of esophagus did not present significant differences, which contrasts with the results of international publications. The analyses demonstrated that the low third is the only parameter that is subject to variation, which relates to the metaplasia of Barrett and the development of oesophageal adenocarcinoma.

Sustainable management of lakes in connection with mitigation of adverse effects of climate change, agriculture and development of green micro regions based on renewable energy production

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Sandor Antal Nemethy

2014-11-01

Full Text Available Lake management is extremely complex and requires a coordinated effort of research institutions, community groups, individuals, landowners, and government. Lakes constitute an important group of natural resources due to their ecosystem services and often unique cultural environments. Climate change is a growing concern, which particularly strongly affects shallow lakes. The adverse impact of climate change is enhanced by extreme water level fluctuations and human factors such as environmental pollution from waste water discharge, large scale agriculture and shoreline constructions reducing or eliminating valuable wetlands. Since eutrophication is a leading cause of impairment of freshwater ecosystems, specific strategies to address a lake's nutrient enrichment must focus on activities in the watershed and, if needed, in-lake restoration techniques. Analyzing the key factors of sustainable local and regional development in the vicinity of lakes, assessing the environmental risks of pollution, large scale agriculture, waste management and energy production, we propose a complex, stakeholder based management system and holistic regional development in lake areas, which will preserve natural ecosystems without compromising the sustainable use of ecosystem services. There are available technologies to develop ecologically acceptable water level regulations, promote organic agriculture applying grey water irrigation, stop leachate from landfills and control invasive species. Regional and local production and use of renewable energy is essential both for environmental and economical sustainability. Renewable energy production should be well coordinated with agriculture, forestry, waste management and management of water resources of lakes and their watershed areas in a sustainable, holistic way through a participatory approach. This is particularly pronounced in connection with tourism as one of the main uses of lake-ecosystem services, but also an

[Motivation perception measurement of intermediate directors in three complex hospitals of the Region of the Maule, Chile].

Science.gov (United States)

Bustamante-Ubilla, Miguel Alejandro; del Río-Rivero, María Carolina; Lobos-Andrade, Germán Enrique; Villarreal-Navarrete, Patricia Isabel

2009-01-01

In this work, a questionnaire was designed and perceptions of motivation and demotivation of middle managers in three hospitals in the Region del Maule, Chile were measured. The fieldwork was carried out between September and October, 2006. A questionnaire that included 57 statements to measure attitude was administered and qualified according to a five-point Likert-type scale. The population studied included l25 professionals that supervise roughly 3 800 employees. Ten variables were identified, 5 motivational and 5 demotivational. Notable among the motivational variables are vocation and service-oriented spirit; among the demotivational variables are lack of recognition and commitment. It is affirmed that both motivational variables as well as demotivational variables are essentially qualitative and that economic and salary variables are less relevant and less hierarchical.

Evaluation of the hydrogeological interconnection between the Salar de Maricunga and the Piedra Pomez basins, Atacama Region, Chile; An isotope and geochemical approach

International Nuclear Information System (INIS)

Iriarte, S.; Santibanez, I; Aravena, R

2001-01-01

Groundwater is the main water source for the mining industry in the Altiplano of northern Chile. Groundwater also plays a significant role as a water source for lagoons, wetlands and salares, which are important ecosystems for animal life and vegetation communities that exist in this arid region. The rational use and protection of the groundwater resource requires a good understanding of the aquifer systems. One of the key components in the assessment of water resources in Northern Chile, is the hydrogeological interconnection between basins. During the last three years, as part of a major hydrogeological project, Sernageomin has been working in the Altiplano of the Atacama region (Iriarte et al., 1998; Iriarte, 1999; Venegas et al., 2000; Santibanez, in prep.). This study included the evaluation of the geometry and groundwater potential of the aquifers and the chemical characterization of the surface and groundwater. Part of this study has focused on the Salar de Maricunga and the Campo de Piedra Pomez basins, due to an increasing demand for groundwater resources in this area by the mining industry. This paper discusses the use of isotope and geochemical tools that were used to evaluate the hydrogeological interconnection between the Salar de Maricunga and the Piedra Pomez basins. The geological and hydrogeological framework of this work is discussed in detail by Iriarte (1999) (au)

L-Lake macroinvertebrate community

International Nuclear Information System (INIS)

Specht, W.L.

1996-06-01

To characterize the present benthic macroinvertebrate community of L-Lake, Regions 5 and 7 of the reservoir were sampled in September 1995 at the same locations sampled in 1988 and 1989 during the L-Lake monitoring program. The macroinvertebrate community of 1995 is compared to that of 1988 and 1989. The species composition of L-Lake's macroinvertebrate community has changed considerably since 1988-1989, due primarily to maturation of the reservoir ecosystem. L-Lake contains a reasonably diverse macroinvertebrate community that is capable of supporting higher trophic levels, including a diverse assemblage of fish species. The L-Lake macroinvertebrate community is similar to those of many other southeastern reservoirs, and there is no indication that the macroinvertebrate community is perturbed by chemical or physical stressors

L-Lake macroinvertebrate community

Energy Technology Data Exchange (ETDEWEB)

Specht, W.L.

1996-06-01

To characterize the present benthic macroinvertebrate community of L-Lake, Regions 5 and 7 of the reservoir were sampled in September 1995 at the same locations sampled in 1988 and 1989 during the L-Lake monitoring program. The macroinvertebrate community of 1995 is compared to that of 1988 and 1989. The species composition of L-Lake`s macroinvertebrate community has changed considerably since 1988-1989, due primarily to maturation of the reservoir ecosystem. L-Lake contains a reasonably diverse macroinvertebrate community that is capable of supporting higher trophic levels, including a diverse assemblage of fish species. The L-Lake macroinvertebrate community is similar to those of many other southeastern reservoirs, and there is no indication that the macroinvertebrate community is perturbed by chemical or physical stressors.

Range expansion of Oligoryzomys longicaudatus (Rodentia, Sigmodontinae in Patagonian Chile, and first record of Hantavirus in the region Ampliación del rango de distribución de Oligoryzomys longicaudatus (Rodentia, Sigmodontinae en la Patagonia de Chile y primer registro de Hantavirus en la región

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SEBASTIÁN BELMAR-LUCERO

2009-06-01

Full Text Available At present, 20 species of Oligoryzomys (Rodentia, Sigmodontinae are recognized in the Neotropical region, most of them distinguished by their karyotypes, which fluctuates between 46-70 chromosomes. Two species are currently recognized in Chile, Oligoryzomys longicaudatus (Bennet, 1832; "colilargo" or the long-tailed pygmy rice rat; 2n = 56, which ranges from 27° to approximately 51° S, and O. magellanicus (Bennet, 1836; Magellanic pygmy rice rat; 2n = 54, south of 51° S in the Patagonian region of Chile and Argentina. As part of an ongoing research on the southern Patagonia of Chile, we report the results of small mammal samplings in six localities. We karyotyped 28 specimens and we also sequenced the hypervariable mtDNA region I in 22 individuals, aligning these sequences with an under development phylogeny of O. longicaudatus. We also evaluated the serology and viral charge in all captured specimens to detect the presence of antibodies to Andes virus (ANDV through Strip Immunoblot Assay (SIA, and of viral genome by RT-PCR. The results consistently showed that the karyotype of southern Patagonia specimens was 2n = 56, equal to that of O. longicaudatus, and that individuals from this area do not differentiate phylogenetically from those of the northern range of distribution. In addition, the serology showed the presence of antibodies IgG anti-ANDV and of viral genome in heart, kidney, spleen, and lungs of a single specimen of Oligoryzomys from the locality of Fuerte Bulnes in the Magallanes region. We conclude that all specimens trapped south of 51° S correspond to Oligoryzomys longicaudatus, thus expanding the distribution of this specie! from 51° to at least 55° S. The results also extended the disiribution of the Andes strain of Hantavirus to southernmost Patagonia.Actualmente se reconocen 20 especies de Oligoryzomys (Rodentia, Sigmodontinae en la región Neotropical, la mayoría de ellas distinguidas por sus cariotipos, los que fluct

Zooplankton communities in a large prealpine lake, Lake Constance: comparison between the Upper and the Lower Lake

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Gerhard MAIER

2005-08-01

reproduction of zooplanktivorous European whitefish, Coregonus lavaretus, which feeds highly selectively on large cladocerans and which is of great economic significance for the whole region. Another possibility could be that the lack of large Cladocera in the Lower Lake is a result of strong fish predation which could be a consequence of lake morphology.

The PIRLA project: paleoecological investigations of recent lake acidification

Energy Technology Data Exchange (ETDEWEB)

Charles, D F; Whitehead, D R

1986-12-19

The PIRLA project is a broadly interdisciplinary paleolimnological investigation of five to fifteen comparable watershed lake systems from each of four low-alkalinity regions in North America that are currently receiving acid deposition. The areas are the Adirondack Mountains (N.Y.), northern New England, northern Great Lakes states, and northern Florida. The primary objective of the study is to provide a detailed reconstruction of the recent acidification histories of a representative suite of lakes from each of the regions. The study will increase our understanding of the timing, rates, and magnitude of acidification (and other chemical changes), and the regional and inter-regional patterns of lake acidification. 3 figs., 2 tabs., 41 refs.

Current Discussions Between ESO and Chile

Science.gov (United States)

1995-04-01

[Joint Press Release by the Government of the Republic of Chile and the European Southern Observatory. The text is issued simultaneously in Santiago de Chile (in Spanish) and at the ESO Headquarters in Garching (in English).] Today, Tuesday, 18 April 1995, at the ESO Headquarters in Garching (Germany), Mr. Roberto Cifuentes, Plenipotentiary Ambassador representing the Government of the Republic of Chile, and the Director General of the European Southern Observatory, Professor Riccardo Giacconi, have signed a Supplementary, Interpretative and Amending Agreement to the Convention of 6 November 1963 which governs the relations between Chile and this International Organisation. This Agreement which in practice signifies a widening and strengthening of the cooperative relations between the Organisation and the Chilean scientific community will hereafter be submitted for ratification by the National Congress of the Republic of Chile (the Parliament) and by the ESO Council. According to the Agreement signed today, Chilean astronomers will have privileged access within up to 10 percent observing time on all present and future ESO telescopes in Chile. Moreover, ESO accepts to incorporate into its labour regulations for Chilean personnel concepts like freedom of association and collective bargaining. This signing of the Supplementary, Interpretative and Amending Agreement to the original Convention of 1963 follows after months of constructive dialogue between the parties. It constitutes an important step towards a solution of some of the pending points on the current agenda for discussions between the Government of Chile and ESO. Among the issues still pending, ESO has informed the Government of Chile that respect for its immunities by the Chilean State is of vital importance for the continuation of the construction of the world's largest telescope at Paranal, as well as the continued presence of the Organisation in Chile. The Chilean Government, on its side, and concerning

The predominance of young carbon in Arctic whole-lake CH4 and CO2 emissions and implications for Boreal yedoma lakes.

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Elder, C.; Xu, X.; Walker, J. C.; Walter Anthony, K. M.; Pohlman, J.; Arp, C. D.; Townsend-Small, A.; Hinkel, K. M.; Czimczik, C. I.

2017-12-01

Lakes in Arctic and Boreal regions are hotspots for atmospheric exchange of the greenhouse gases CO2 and CH4. Thermokarst lakes are a subset of these Northern lakes that may further accelerate climate warming by mobilizing ancient permafrost C (> 11,500 years old) that has been disconnected from the active C cycle for millennia. Northern lakes are thus potentially powerful agents of the permafrost C-climate feedback. While they are critical for projecting the magnitude and timing these feedbacks from the rapidly warming circumpolar region, we lack datasets capturing the diversity of northern lakes, especially regarding their CH4contributions to whole-lake C emissions and their ability to access and mobilize ancient C. We measured the radiocarbon (14C) ages of CH4 and CO2 emitted from 60 understudied lakes and ponds in Arctic and Boreal Alaska during winter and summer to estimate the ages of the C sources yielding these gases. Integrated mean ages for whole-lake emissions were inferred from the 14C-age of dissolved gases sampled beneath seasonal ice. Additionally, we measured concentrations and 14C values of gases emitted by ebullition and diffusion in summer to apportion C emission pathways. Using a multi-sourced mass balance approach, we found that whole-lake CH4 and CO2 emissions were predominantly sourced from relatively young C in most lakes. In Arctic lakes, CH4 originated from 850 14C-year old C on average, whereas dissolved CO2 was sourced from 400 14C-year old C, and represented 99% of total dissolved C flux. Although ancient C had a minimal influence (11% of total emissions), we discovered that lakes in finer-textured aeolian deposits (Yedoma) emitted twice as much ancient C as lakes in sandy regions. In Boreal, yedoma-type lakes, CH4 and CO2 were fueled by significantly older sources, and mass balance results estimated CH4-ebullition to comprise 50-60% of whole-lake CH4 emissions. The mean 14C-age of Boreal emissions was 6,000 14C-years for CH4-C, and 2

Hydro-climatic trends and water resource management implications based on multi-scale data for the Lake Victoria region, Kenya

International Nuclear Information System (INIS)

Koutsouris, A J; Destouni, G; Jarsjoe, J; Lyon, S W

2010-01-01

Unreliable rainfall may be a main cause of poverty in rural areas, such as the Kisumu district by Lake Victoria in Kenya. Climate change may further increase the negative effects of rainfall uncertainty. These effects could be mitigated to some extent through improved and adaptive water resource management and planning, which relies on our interpretations and projections of the coupled hydro-climatic system behaviour and its development trends. In order to identify and quantify the main differences and consistencies among such hydro-climatic assessments, this study investigates trends and exemplifies their use for important water management decisions for the Lake Victoria drainage basin (LVDB), based on local scale data for the Orongo village in the Kisumu district, and regional scale data for the whole LVDB. Results show low correlation between locally and regionally observed hydro-climatic trends, and large differences, which in turn affects assessments of important water resource management parameters. However, both data scales converge in indicating that observed local and regional hydrological discharge trends are primarily driven by local and regional water use and land use changes.

Current situation of women in the workplace in Chile

OpenAIRE

Cábová, Helena

2016-01-01

This diploma thesis examines the problem of the situation of women in the workplace in Chile. The thesis is divided into three parts, while each parts gradually analyses the problem of gender inequalities. Firstly, the thesis presents the overall information about the general problem of gender inequalities. It introduces the basic fragments of the issue together with the basic terminology. Secondly, a major focus is put on the Chilean regions, as it analyses gender differences of the regions ...

[Microbiologic and molecular diagnostic of cariogenic bacteria in pregnant women from the Araucania Region of Chile].

Science.gov (United States)

Herrera G, Christian L; Pantoja F, Patricio; De la M, Tomás de La Maza; Sanhueza C, Antonio; Salazar N, Luis A

2007-08-01

Dental caries is a transmissible infectious disease in which Streptococcus mutans is a principal protagonist. Although it is widely believed that pregnancy is harmful to teeth, the effect of pregnancy on the development of caries is not clear. Considering this situation, the aim of the present study was to evaluate the levels of infection and to differentiate bacterial species with cariogenic potential in pregnant women from the Araucania region in Chile, by bacteriological and molecular analysis. In this work, we evaluated 51 pregnant women aged 15 to 40 years. The results show that 100% of women are infected by mutans streptococci Group, and 70.6% exhibited high levels of infection (> 500.000 cfu/mL). The molecular analysis shows that Streptococcus mutans and Streptococcus sobrinus frequencies were 92.1% and 1.9%, respectively. In conclusion, our data suggest that pregnant women are a high risk group for caries development.

Internationalization of SMES: business opportunities in Chile

OpenAIRE

Correia, João Filipe Amado

2016-01-01

The main goal of this study is to identify the main business opportunities in Chile, legal advantages in the business perspective and entry strategies for small and medium sized enterprises (SMEs). The methodology used was qualitative, by conducting several interviews with chamber of commerce representative from Portugal in Chile and Chile in Portugal, several young entrepreneurs from different nations operating in Chile, the CEO of a Spanish company that decided to not internationalize to...

Oligotrophic patterns in southern Chilean lakes: the relevance of nutrients and mixing depth Patrones oligotróficos en lagos del sur de Chile: relevancia de los nutrientes y de la profundidad de mezcla

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DORIS SOTO

2002-06-01

Full Text Available Southern Chilean monomictic, temperate lakes are generally oligotrophic with high water transparency, low productivity and some apparent resistance to disturbances such as phosphorus additions. This paper attempts to explain low chlorophyll-a values using descriptive and experimental approaches. Three different scales are used, (a a micro scale both in space and time, with experimental manipulations of N, P and total light in 24 enclosures in lake Llanquihue, (b a longer time scale analysing 18 months of data in several sites within lake Llanquihue grouped as salmon farming sites, town bays and control sites, and (c a broader time scale (9 years by monitoring lakes Puyehue, Rupanco and Llanquihue, all in the Araucanian lake region and Yelcho lake in the north Patagonian region. In the Llanquihue in-lake sampling, total phosphorus values varied between 1 and 12 mug L-1 between sites, showing marginal site effects, P = 0.09 (salmon sites had greater values, however, chlorophyll a (Chl-a concentrations were generally low (Los lagos monomicticos templados del sur de Chile son generalmente oligotróficos de gran transparencia, baja productividad y aparente resistencia a perturbaciones tales como adiciones de fósforo. Este trabajo intenta explicar los bajos valores de clorofila de acuerdo a aproximaciones descriptivas y experimentales. Se utilizan aquí tres escalas de aproximación; (a una microescala en espacio y tiempo con manipulaciones experimentales de nitrógeno (N, fósforo (P y luz en 24 limnocorrales ubicados en una bahía del lago Llanquihue, (b una escala mayor analizando 18 meses de muestreo en 10 sitios del lago Llanquihue agrupados como sitios de cultivo de salmones, bahías de ciudades y sitios de control, (c una escala aún mayor en tiempo y espacio monitoreando semestralmente por 9 años los lagos Puyehue, Rupanco, Llanquihue en la región de los Lagos Araucanos y el lago Yelcho en la región nor- patagónica. En el muestreo intra

Estimation of lake water - groundwater interactions in meromictic mining lakes by modelling isotope signatures of lake water.

Science.gov (United States)

Seebach, Anne; Dietz, Severine; Lessmann, Dieter; Knoeller, Kay

2008-03-01

A method is presented to assess lake water-groundwater interactions by modelling isotope signatures of lake water using meteorological parameters and field data. The modelling of delta(18)O and deltaD variations offers information about the groundwater influx into a meromictic Lusatian mining lake. Therefore, a water balance model is combined with an isotope water balance model to estimate analogies between simulated and measured isotope signatures within the lake water body. The model is operated with different evaporation rates to predict delta(18)O and deltaD values in a lake that is only controlled by weather conditions with neither groundwater inflow nor outflow. Comparisons between modelled and measured isotope values show whether the lake is fed by the groundwater or not. Furthermore, our investigations show that an adaptation of the Craig and Gordon model [H. Craig, L.I. Gordon. Deuterium and oxygen-18 variations in the ocean and the marine atmosphere. In Stable Isotopes in Oceanographic Studies and Paleotemperature, Spoleto, E. Tongiorgi (Ed.), pp. 9-130, Consiglio Nazionale delle Ricerche, Laboratorio di Geologia Nucleare, Pisa (1965).] to specific conditions in temperate regions seems necessary.

The impact of an urban-industrial region on the magnitude and variability of persistent organic pollutant deposition to Lake Michigan.

Science.gov (United States)

Hornbuckle, Keri C; Green, Mark L

2003-09-01

A predictive model for gas-phase PCBs and trans-nonachlor over Lake Michigan has been constructed and the resulting data examined for trends. In this paper, we describe the model results to show how the magnitude and variability of a plume of contaminants from the Chicago area contributes to a highly variable region of net contaminant deposition over the entire lake. For the whole lake, gross annual deposition of PCBs is approximately 3200 kg, although the net annual gas exchange is not significantly different from zero. The data-driven model illustrates that on a daily basis, the net exchange of persistent organic pollutants (POPs) can change from net deposition to net volatilization depending on the area of plume impact. These findings suggest that i) control of urban areas can accelerate the rate of volatilization from lakes; and ii) release of POPs from urban areas is largely a result of volatilization processes.

Climate Change Impacts on Nutrient Losses of Two Watersheds in the Great Lakes Region

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Lili Wang

2018-04-01

Full Text Available Non-point sources (NPS of agricultural chemical pollution are one major reason for the water quality degradation of the Great Lakes, which impacts millions of residents in the states and provinces that are bordering them. Future climate change will further impact water quality in both direct and indirect ways by influencing the hydrological cycle and processes of nutrient transportation and transformation, but studies are still rare. This study focuses on quantifying the impacts of climate change on nutrient (Nitrogen and Phosphorus losses from the two small watersheds (Walworth watershed and Green Lake watershed within the Great Lakes region. Analysis focused on changes through this century (comparing the nutrient loss prediction of three future periods from 2015 to 2099 with 30 years for each period against the historical nutrient estimation data from 1985 to 2008. The effects on total phosphorus and nitrate-nitrogen losses due to changes in precipitation quantity, intensity, and frequency, as well as air temperature, are evaluated for the two small watersheds, under three special report emission scenarios (SRES A2, A1B, B1. The newly developed Water Erosion Prediction Project-Water Quality (WEPP-WQ model is utilized to simulate nutrient losses with downscaled and bias corrected future climate forcing from two General Circulation Models (GFDL, HadCM3. For each watershed, the observed runoff and nutrient loads are used to calibrate and validate the model before the application of the WEPP-WQ model to examine potential impacts from future climate change. Total phosphorus loss is projected to increase by 28% to 89% for the Green Lake watershed and 25% to 108% for the Walworth watershed mainly due to the combined effects of increase of precipitation quantity, extreme storm events in intensity and frequency, and air temperature. Nitrate-nitrogen losses are projected to increase by 1.1% to 38% for the Green Lake watershed and 8% to 95% for the

Genetic diversity and structure in semiwild and domesticated chiles (Capsicum annuum; Solanaceae) from Mexico.

Science.gov (United States)

Aguilar-Meléndez, Araceli; Morrell, Peter L; Roose, Mikeal L; Kim, Seung-Chul

2009-06-01

The chile of Mesoamerica, Capsicum annuum, is one of five domesticated chiles in the Americas. Among the chiles, it varies the most in size, form, and color of its fruits. Together with maize, C. annuum is one of the principal elements of the neotropical diets of Mesoamerican civilizations. Despite the great economic and cultural importance of C. annuum both worldwide and in Mexico, however, very little is known about its geographic origin and number of domestications. Here we sampled a total of 80 accessions from Mexico (58 semiwild and 22 domesticated) and examined nucleotide sequence diversity at three single- or low-copy nuclear loci, Dhn, G3pdh, and Waxy. Across the three loci, we found an average reduction of ca. 10% in the diversity of domesticates relative to semiwild chiles and geographic structure within Mexican populations. The Yucatan Peninsula contained a large number of haplotypes, many of which were unique, suggesting an important region of chile domestication and center of diversity. The present sampling of loci did not conclusively resolve the number and location of domestications, but several lines of evidence suggest multiple independent domestications from widely distributed progenitor populations.

[Vaginal infections in a Family Health Clinic in the Metropolitan Region, Chile].

Science.gov (United States)

Villaseca, Rodrigo; Ovalle, Alfredo; Amaya, Fernando; Labra, Bayron; Escalona, Natalia; Lizana, Paola; Montoya, M José; Lillo, Eduardo; Martínez, M Angélica

2015-02-01

Vaginal infections are a frequent cause for consultation, but their prevalence and etiology vary in different populations. To determine the prevalence and etiologies of vaginal infection in women attending a family health center in the Metropolitan Region of Chile. The microbiological diagnosis was made by wet mount and Gram stain. Diagnosis of trichomoniasis was performed by wet mount, culture and polymerase chain reaction. 101 women aged 15-54, not selected by signs or symptoms of vaginal infection, 46 of them pregnant were included. In 47 women (46.5%), vaginal infections were diagnosed. An association was observed between age and frequency of vaginal infection. The proportion of infections among pregnant and non-pregnant women was similar. The most frequent infections were bacterial vaginosis (16.8%), vulvovaginal candidiasis (11.9%) and co-infections (6.9%). We found 5.9% of intermediate microbiota cases, 3% of trichomoniasis and 2% of aerobic vaginitis. Symptoms of vaginal infection had poor agreement with microbiological findings. Otherwise physical signs had good agreement with the presence of infection, but low to moderate concordance with a specific etiology. We found a high prevalence of vaginal infections in the study population. It is necessary to improve the definitions and criteria of microbiological diagnosis of co-infections and intermediate microbiota, for them to be diagnosed in the clinical practice. More descriptive questionnaires are recommended to enhance the usefulness of clinical examination.

Challenges for psychiatric recruitment and training in Chile.

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Vicente, Benjamín; Rosel, Leonardo

2013-08-01

This paper aims to describe the current challenges to recruitment of psychiatrists in Chile, and investigate factors related to interest in psychiatry from medical students of the Chilean Biobío Region. An online survey was completed by 39 medical students currently performing the internship. This survey included questions regarding socio-demographic aspects, probability of choosing a medical speciality, influencing factors on the choice of the medical speciality, and personal features. Students were separated in two groups for the analysis based on their likelihood of choosing psychiatry as a career. A total of 35.9% of the respondents showed some degree of interest in psychiatry. Factors considered important by the respondents were academic opportunities, training vacancies, and balance between job and personal life. The low participation in the study does not allow the extrapolation of data to the national situation, and may represent response bias to those already interested in psychiatry as a career. However, Chile has an average psychiatrist rate per number of inhabitants for the region, but an uneven distribution of this resource. National policies must be focused on this issue in order to reduce the gap in mental healthcare.

Climate change impacts on municipal, mining, and agricultural water supplies in Chile

Science.gov (United States)

Daniel G. Neary; Pablo Garcia-Chevesich

2008-01-01

Agricultural and municipal water supply interests in Chile rely heavily on streams which flow from the Andes Mountains. The highly productive Copiapo agricultural region, on the southern edge of the Atacama Desert, is a major supplier of fruit and other crops for the Northern American market during winter. This region relies entirely on snow and icemelt streams to...

Trends in summer chemistry linked to productivity in lakes recovering from acid deposition in the Adirondack region of New York

Science.gov (United States)

Momen, B.; Lawrence, G.B.; Nierzwicki-Bauer, S. A.; Sutherland, J.W.; Eichler, L.W.; Harrison, J.P.; Boylen, C.W.

2006-01-01

The US Environmental Protection Agency established the Adirondack Effects Assessment Program (AEAP) to evaluate and monitor the status of biological communities in lakes in the Adirondack region of New York that have been adversely affected by acid deposition. This program includes chemical analysis of 30 lakes, sampled two to three times each summer. Results of trends analysis for lake chemistry and chlorophyll a (chlor a) are presented for 1994 to 2003, and a general comparison is made with recent results of the Adirondack Long-Term Monitoring (ALTM) Program, which included chemical analysis of all but two of these lakes (plus an additional 24 lakes) monthly, year-round for 1992-2004. Increases in pH were found in 25 of the 30 AEAP lakes (P level of P level of P level of P level of P level of P chemistry were similar to those of the ALTM Program, although decreases in SO 42- concentrations were more evident in the year-round ALTM record. Overall, the results suggest (a) a degree of chemical recovery from acidification during the summer, (b) an increase in phytoplankton productivity, and (c) a decreasing trend in NO 3- concentrations resulting from the increased productivity. ?? 2007 Springer Science+Business Media, Inc.

The limnology of L Lake: Results of the L-Lake monitoring program, 1986--1989

Energy Technology Data Exchange (ETDEWEB)

Bowers, J.A.

1991-12-15

L Lake was constructed in 1985 on the upper regions of Steel Creek, SRS to mitigate the heated effluents from L Reactor. In addition to the NPDES permit specifications (Outfall L-007) for the L-Reactor outfall, DOE-SR executed an agreement with the South Carolina Department of Health and Environmental Control (SCDHEC), that thermal effluents from L-Reactor will not substantially alter ecosystem components in the approximate lower half of L Lake. This region should be inhabited by Balanced (Indigenous) Biological Communities (BBCs) in accordance with Section 316(a) of the Pollution Control (Clean Water) Act (Public Law 92-500). In response to this requirement the Environmental Sciences Section/Ecology Group initiated a comprehensive biomonitoring program which documented the development of BBCs in L Lake from January 1986 through December 1989. This report summarizes the principal results of the program with regards to BBC compliance issues and community succession in L Lake. The results are divided into six sections: water quality, macronutrients, and phytoplankton, aquatic macrophytes, zooplankton, benthic macroinvertebrates, fish, and community succession. One of the prime goals of the program was to detect potential reactor impacts on L Lake.

Rule of Repression in Chile.

Science.gov (United States)

American Indian Journal, 1979

1979-01-01

This report on the current condition of the Mapuche Indians of Chile is edited from a document on the "Situation of Human Rights in Chile" and details the repressive and inhumane treatment of the largest indigenous ethnic minority in the country. (Author/RTS)

[Spatial Distribution Characteristics of Different Species Mercury in Water Body of Changshou Lake in Three Gorges Reservoir Region].

Science.gov (United States)

Bai, Wei-yang; Zhang, Cheng; Zhao, Zheng; Tang, Zhen-ya; Wang, Ding-yong

2015-08-01

An investigation on the concentrations and the spatial distribution characteristics of different species of mercury in the water body of Changshou Lake in Three Gorges Reservoir region was carried out based on the AreGIS statistics module. The results showed that the concentration of the total mercury in Changshou Lake surface water ranged from 0.50 to 3.78 ng x L(-1), with an average of 1.51 ng x L(-1); the concentration of the total MeHg (methylmercury) ranged from 0.10 to 0.75 ng x L(-1), with an average of 0.23 ng x L(-1). The nugget effect value of total mercury in surface water (50.65%), dissolved mercury (49.80%), particulate mercury (29.94%) and the activity mercury (26.95%) were moderate spatial autocorrelation. It indicated that the autocorrelation was impacted by the intrinsic properties of sediments (such as parent materials and rocks, geological mineral and terrain), and on the other hand it was also disturbed by the exogenous input factors (such as aquaculture, industrial activities, farming etc). The nugget effect value of dissolved methylmercury (DMeHg) in Changshou lake surface water (3.49%) was less than 25%, showing significant strong spatial autocorrelation. The distribution was mainly controlled by environmental factors in water. The proportion of total MeHg in total Hg in Changshou Lake water reached 30% which was the maximum ratio of the total MeHg to total Hg in freshwater lakes and rivers. It implied that mercury was easily methylated in the environment of Chanashou Lake.

Análisis de eficiencia hospitalaria en Chile

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Planck Barahona-Urbina

2011-01-01

Full Text Available Introducción: La importancia del análisis envolvente de datos (AED radica en poder determinar cuáles de los hospitales regionales presentan un mejor desempeño relativo y cuáles podrían mejorar el uso de los recursos. Objetivos: Analizar, haciendo uso de la técnica no paramétrica de análisis envolvente de datos, la eficiencia técnica hospitalaria en Chile. Diseño: Análisis de tipo no paramétrico. Lugar: Hospitales públicos regionales de Chile. Intervenciones: Aplicación del AED para la evaluación de la eficiencia de los establecimientos de la salud. Materiales: Se utilizó datos para el período comprendido entre 1997 y 2006 de las doce regiones del país más la región Metropolitana (RM, de 190 hospitales públicos de distintos grados de especialización. Se identificó datos de actividad hospitalaria y personal facultativo, esto es, como inputs a médicos, enfermeras, matronas, camas disponibles, y como variable output el egreso hospitalario. Principales medidas de resultados: Eficiencia hospitalaria. Resultados: En el año 1997, las regiones IV, VII, VIII, y IX fueron calificadas como técnicamente eficientes, lo que ha significado que han hecho un adecuado uso de sus recursos. Conclusiones: En diez años de estudio, 1997 a 2006, únicamente en el año 1997 cuatro regiones de Chile fueron eficientes. Los hospitales regionales deberían reducir sus inputs en promedio un 10% para situarse sobre la frontera eficiente. El análisis DEA es una buena herramienta para llevar a cabo mediciones de eficiencia y evaluar resultados de gestión, pues permite conocer aquellas unidades que realizan la mejor asignación de sus recursos en comparación al resto de la muestra.

Mercury in fish from the Pinchi Lake Region, British Columbia, Canada

International Nuclear Information System (INIS)

Weech, S.A.; Scheuhammer, A.M.; Elliott, J.E.; Cheng, K.M.

2004-01-01

Water, surface sediments, and <40 cm rainbow trout (Oncorhynchus mykiss) and northern pikeminnow (Ptychocheilus oregonensis) were collected from Pinchi Lake, British Columbia, and from several nearby reference lakes. Hg concentrations in sediment samples from Pinchi L. were highly elevated compared to sediments from reference lakes, especially in sites adjacent to and downstream of a former Hg mine. In both fish species examined, Hg concentration was positively related to age and/or fork length. In northern pikeminnow, Hg concentrations were also positively related to trophic level (δN). Hg concentrations in both fish species were highest in Pinchi L., and were higher in pikeminnow than in rainbow trout of similar size. Average Hg concentrations in small rainbow trout from all lakes, including Pinchi L., were lower than dietary levels reported to cause reproductive impairment in common loons (Gavia immer); however, Hg levels in small pikeminnow from Pinchi L. were sufficiently high to be of concern. The risk for Hg toxicity in the study area is greatest for animals that consume larger piscivorous fish such as larger northern pikeminnow or lake trout, which are known from previous studies to contain higher Hg concentrations

Landscape connectivity among remnant populations of guanaco (Lama guanicoe Müller, 1776) in an arid region of Chile impacted by global change.

Science.gov (United States)

Espinosa, Mara I; Gouin, Nicolas; Squeo, Francisco A; López, David; Bertin, Angéline

2018-01-01

Connectivity between populations plays a key role in the long-term persistence of species in fragmented habitats. This is of particular concern for biodiversity preservation in drylands, since water limited landscapes are typically characterized by little suitable habitat cover, high habitat fragmentation, harsh matrices, and are being rapidly degraded at a global scale. In this study, we modelled landscape connectivity between 11 guanaco Lama guanicoe populations in Chile's arid Norte Chico, a region that supports the last remnant coastal populations of this emblematic herbivore indigenous to South America. We produced a habitat suitability model to derive a regional surface resistance map, and used circuit theory to map functional connectivity, investigate the relative isolation between populations, and identify those that contribute most to the patch connectivity network. Predicted suitable habitat for L. guanicoe represented about 25% of the study region (i.e., 29,173 km 2 ) and was heterogeneously distributed along a continuous stretch along the Andes, and discontinuous patches along the coast. As a result, we found that high connectivity current flows in the mid and high Andes formed a wide, continuous connectivity corridor, enabling connectivity between all high Andean populations. Coastal populations, in contrast, were more isolated. These groups demonstrate no inter-population connectivity between themselves, only with higher altitude populations, and for two of them, animal movement was linked to the effectiveness of wildlife crossings along the Pan-American highway. Our results indicate that functional connectivity is an issue of concern for L. guanicoe in Chile's Norte Chico, implying that future conservation and management plans should emphasize strategies aimed at conserving functional connectivity between coastal and Andean populations, as well as the protection of habitat patches likely to act as stepping stones within the connectivity network.

Developing Flexible, Integrated Hydrologic Modeling Systems for Multiscale Analysis in the Midwest and Great Lakes Region

Science.gov (United States)

Hamlet, A. F.; Chiu, C. M.; Sharma, A.; Byun, K.; Hanson, Z.

2016-12-01

Physically based hydrologic modeling of surface and groundwater resources that can be flexibly and efficiently applied to support water resources policy/planning/management decisions at a wide range of spatial and temporal scales are greatly needed in the Midwest, where stakeholder access to such tools is currently a fundamental barrier to basic climate change assessment and adaptation efforts, and also the co-production of useful products to support detailed decision making. Based on earlier pilot studies in the Pacific Northwest Region, we are currently assembling a suite of end-to-end tools and resources to support various kinds of water resources planning and management applications across the region. One of the key aspects of these integrated tools is that the user community can access gridded products at any point along the end-to-end chain of models, looking backwards in time about 100 years (1915-2015), and forwards in time about 85 years using CMIP5 climate model projections. The integrated model is composed of historical and projected future meteorological data based on station observations and statistical and dynamically downscaled climate model output respectively. These gridded meteorological data sets serve as forcing data for the macro-scale VIC hydrologic model implemented over the Midwest at 1/16 degree resolution. High-resolution climate model (4km WRF) output provides inputs for the analyses of urban impacts, hydrologic extremes, agricultural impacts, and impacts to the Great Lakes. Groundwater recharge estimated by the surface water model provides input data for fine-scale and macro-scale groundwater models needed for specific applications. To highlight the multi-scale use of the integrated models in support of co-production of scientific information for decision making, we briefly describe three current case studies addressing different spatial scales of analysis: 1) Effects of climate change on the water balance of the Great Lakes, 2) Future

Emergence of Viral hemorrhagic septicemia virus in the North American Great Lakes region is associated with low viral genetic diversity.

Science.gov (United States)

Thompson, Tarin M; Batts, William N; Faisal, Mohamed; Bowser, Paul; Casey, James W; Phillips, Kenneth; Garver, Kyle A; Winton, James; Kurath, Gael

2011-08-29

Viral hemorrhagic septicemia virus (VHSV) is a fish rhabdovirus that causes disease in a broad range of marine and freshwater hosts. The known geographic range includes the Northern Atlantic and Pacific Oceans, and recently it has invaded the Great Lakes region of North America. The goal of this work was to characterize genetic diversity of Great Lakes VHSV isolates at the early stage of this viral emergence by comparing a partial glycoprotein (G) gene sequence (669 nt) of 108 isolates collected from 2003 to 2009 from 31 species and at 37 sites. Phylogenetic analysis showed that all isolates fell into sub-lineage IVb within the major VHSV genetic group IV. Among these 108 isolates, genetic diversity was low, with a maximum of 1.05% within the 669 nt region. There were 11 unique sequences, designated vcG001 to vcG011. Two dominant sequence types, vcG001 and vcG002, accounted for 90% (97 of 108) of the isolates. The vcG001 isolates were most widespread. We saw no apparent association of sequence type with host or year of isolation, but we did note a spatial pattern, in which vcG002 isolates were more prevalent in the easternmost sub-regions, including inland New York state and the St. Lawrence Seaway. Different sequence types were found among isolates from single disease outbreaks, and mixtures of types were evident within 2 isolates from individual fish. Overall, the genetic diversity of VHSV in the Great Lakes region was found to be extremely low, consistent with an introduction of a new virus into a geographic region with previously naive host populations.

Emergence of viral hemorrhagic septicemia virus in the North American Great Lakes region is associated with low viral genetic diversity

Science.gov (United States)

Thompson, T.M.; Batts, W.N.; Faisal, M.; Bowser, P.; Casey, J.W.; Phillips, K.; Garver, K.A.; Winton, J.; Kurath, G.

2011-01-01

Viral hemorrhagic septicemia virus (VHSV) is a fish rhabdovirus that causes disease in a broad range of marine and freshwater hosts. The known geographic range includes the Northern Atlantic and Pacific Oceans, and recently it has invaded the Great Lakes region of North Ame­rica. The goal of this work was to characterize genetic diversity of Great Lakes VHSV isolates at the early stage of this viral emergence by comparing a partial glycoprotein (G) gene sequence (669 nt) of 108 isolates collected from 2003 to 2009 from 31 species and at 37 sites. Phylogenetic analysis showed that all isolates fell into sub-lineage IVb within the major VHSV genetic group IV. Among these 108 isolates, genetic diversity was low, with a maximum of 1.05% within the 669 nt region. There were 11 unique sequences, designated vcG001 to vcG011. Two dominant sequence types, vcG001 and vcG002, accounted for 90% (97 of 108) of the isolates. The vcG001 isolates were most widespread. We saw no apparent association of sequence type with host or year of isolation, but we did note a spatial pattern, in which vcG002 isolates were more prevalent in the easternmost sub-regions, including inland New York state and the St. Lawrence Seaway. Different sequence types were found among isolates from single disease outbreaks, and mixtures of types were evident within 2 isolates from ­individual fish. Overall, the genetic diversity of VHSV in the Great Lakes region was found to be extremely low, consistent with an introduction of a new virus into a geographic region with ­previously naïve host populations.

Una Nota sobre la Construcción de Series de Precios de Activos Reales: Tierra y Casas en Chile Una Nota sobre la Construcción de Series de Precios de Activos Reales: Tierra y Casas en Chile

OpenAIRE

Raimundo Soto; Felipe Morandé

1992-01-01

Una Nota sobre la Construcción de Series de Precios de Activos Reales: Tierra y Casas en Chile This note presents previously unpublished data on prices of agricultural land in Chile's central region and houses (both rental and purchasing prices) in Santiago, with the corresponding methodology. As such, it is a follow-up to an Appendix in Morande (1992).

Immigrant health workers in Chile: is there a Latin American "brain drain"? Inmigración de personal sanitario hacia Chile: ¿hay una "fuga de cerebros" hacia América Latina?

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Baltica Cabieses

2012-08-01

Full Text Available Most research on the phenomenon of "brain drain" (one-way flow of highly skilled/educated individuals has focused on movement between the least developed and most highly developed countries. Therefore, the significance of patterns of migration to middle-income countries such as those in Latin America is less clear. The aim of this study was to outline key features of international health worker "brain drain" to Chile to promote discussion and further research on this phenomenon as it pertains to the Latin American region. The study compared immigrant health workers living in Chile to both Chilean-born health workers and other immigrants living in Chile using a qualitative nationwide dataset (the results of Chile's 2009 National Socioeconomic Characterization Survey. Demographic, socioeconomic, and health-related variables were included in the analyses, which were weighted by population to obtain nationally representative estimates. In 2009, immigrant health workers represented 2.2% of all health personnel and 2.6% of all resident immigrants in the country. While most immigrant health workers had a universitylevel education, about 25% had only a high school-level education or less. There was no statistically significant difference between the distribution of immigrant health workers' household income and that of Chilean-born health workers. A significantly higher proportion of the immigrant group reported no entitlement to health care provision. While the results of this study do not indicate a significant international health worker "brain drain" to Chile, they do suggest distinctive patterns of migration within the Latin American region. Future studies in Chile could confirm the validity of these results, using a larger sample of immigrant health workers.La mayoría de las investigaciones sobre el fenómeno de la "fuga de cerebros" (migración unidireccional de individuos sumamente capacitados y educados se ha centrado en la migración desde pa

Evaluación del primer "Entrenamiento en Metodología de Investigación Clínica en Chile" Evaluation of the first training on clinical research methodology in Chile

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Manuel Espinoza

2011-03-01

Full Text Available Este trabajo describe la evaluación del primer "Entrenamiento en Metodología de Investigación Clínica en Chile (EMIC-Chile tras 12 meses de haber finalizado. Se aplicó una encuesta online para alumnos y el método Delphi para el equipo docente. Entre los estudiantes, la mayoría informó que el programa apoyó su desarrollo profesional y que transmitieron los conocimientos en su lugar de trabajo. El 41% presentó un proyecto a fondos concursables de investigación una vez finalizado el curso. Entre los profesores, las áreas de mayor interés fueron la estrategia comunicacional, la metodología educativa, las características del equipo docente y las posibles estrategias de permanencia de EMIC-Chile a futuro. Esta experincia podría servir a futuras iniciativas de formación en investigación para profesionales de la salud. Se reconocen como desafíos la incorporación de profesiones no médicas en la investigación clínica, complejidades asociadas a la metodología semi-presencial y permanencia duradera de iniciativas de esta envergadura a nivel nacional y regional.This paper describes the evaluation of the first training on clinical research methodology in Chile (EMIC-Chile 12 months after its completion. An online survey was conducted for students and the Delphi method was used for the teaching team. Among the students, the majority reported that the program had contributed to their professional development and that they had shared some of the knowledge acquired with colleagues in their workplace. Forty-one percent submitted a project to obtain research funding through a competitive grants process once they had completed the course. Among the teachers, the areas of greatest interest were the communication strategy, teaching methods, the characteristics of the teaching team, and potential strategies for making the EMIC-Chile permanent in the future. This experience could contribute to future research training initiatives for health

Protecting the Local Dark-Sky Areas around the International Observatories in Chile.

Science.gov (United States)

Smith, M. G.

2001-12-01

This report covers efforts by IAU Commission 50's new Working Group on Light Pollution to slow or halt the spread of incipient light pollution near the VLT, the Magellan 6.5m telescopes, Gemini South, SOAR, Blanco and many smaller telescopes in Chile. An effort has just begun to protect the ALMA site in Northern Chile from RFI. Such work includes extensive outreach programs to the local population, schools and industry as well as to local, regional and national levels of government in Chile. The group is working internationally with such organizations as the IDA; one member has recently led the production of "The first world atlas of the artificial night-sky brightness". These efforts have resulted in the first national-level environmental legislation covering dark skies as part of a government effort to protect the environment. Chilean manufacturers are now producing competitive, full-cut-off, street lighting designed specifically to comply with the new legislation. The Chilean national tourism agency is supporting "Astronomical Tourism" based on the dark, clear skies of Chile. An international conference on Controlling Light Pollution and RFI will be held in La Serena, Chile on 5-7 March, 2002, backed up by a parallel meeting of Chilean amateur astronomers. Much work remains to be done. Most of this work is supported by funding from the US National Science Foundation through CTIO, and from ESO, OCIW and CONAMA.

EL CONEJO EUROPEO EN CHILE: HISTORIA DE UNA INVASIÓN BIOLÓGICA

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Pablo Camus

2008-12-01

Full Text Available Este trabajo analiza las relaciones entre los seres humanos y su ambiente, a partir de la historia de la aclimatación y posterior invasión de conejos en Chile, constatando que, en el largo plazo, las acciones humanas tienen efectos e impactos insospechados sobre el medio natural. En efecto, si bien inicialmente los conejos fueron vistos como una oportunidad de desarrollo económico a partir del aprovechamiento de su piel y su carne, pronto esta especie se convirtió en una plaga difícil de controlar en diversas regiones del país, como Chile central, Tierra del Fuego e islas Juan Fernández. Así, con el paso del tiempo, el conejo se ha terminado por transformar en nuestro país en un verdadero "convidado de piedra".This work analyses the relationship between human beings and their environment taking into consideration the adjustment and eventual invasión of rabbits in Chile. It argües that in the long run, human actions have unsuspected effects upon the environment. In fact rabbits were seen initially as an opportunity for economic development because of the exploitation of their meat and skin. Later, rabbits became a plague in different áreas of Central Chile, Tierra del Fuego and Juan Fernández islands, which was difficult to control. Over the years rabbits became unwelcome guests in Chile.

Differential response of vegetation in Hulun Lake region at the northern margin of Asian summer monsoon to extreme cold events of the last deglaciation

Science.gov (United States)

Zhang, Shengrui; Xiao, Jule; Xu, Qinghai; Wen, Ruilin; Fan, Jiawei; Huang, Yun; Yamagata, Hideki

2018-06-01

The response of vegetation to extreme cold events during the last deglaciation is important for assessing the impact of possible extreme climatic events on terrestrial ecosystems under future global warming scenarios. Here, we present a detailed record of the development of regional vegetation in the northern margin of Asian summer monsoon during the last deglaciation (16,500-11,000 cal yr BP) based on a radiocarbon-dated high-resolution pollen record from Hulun Lake, northeast China. The results show that the regional vegetation changed from subalpine meadow-desert steppe to mixed coniferous and deciduous forest-typical steppe during the last deglaciation. However, its responses to the Heinrich event 1 (H1) and the Younger Dryas event (YD) were significantly different: during the H1 event, scattered sparse forest was present in the surrounding mountains, while within the lake catchment the vegetation cover was poor and was dominated by desert steppe. In contrast, during the YD event, deciduous forest developed and the proportion of coniferous forest increased in the mountains, the lake catchment was occupied by typical steppe. We suggest that changes in Northern Hemisphere summer insolation and land surface conditions (ice sheets and sea level) caused temperature and monsoonal precipitation variations that contributed to the contrasting vegetation response during the two cold events. We conclude that under future global warming scenarios, extreme climatic events may cause a deterioration of the ecological environment of the Hulun Lake region, resulting in increased coniferous forest and decreased total forest cover in the surrounding mountains, and a reduction in typical steppe in the lake catchment.

Hantavirus Public Health outreach effectiveness in three populations: an overview of northwestern New Mexico, Los Santos Panama, and Region IX Chile.

Science.gov (United States)

McConnell, Marjorie S

2014-02-27

This research compared the effectiveness of Hantavirus Pulmonary Syndrome (HPS) outreach programs in New Mexico, Panama, and Chile. Understanding the role of human demographics, disease ecology, and human behavior in the disease process is critical to the examination of community responses in terms of behavior changes. Attitudes, knowledge, and behavior across three populations were measured through the implementation of a self-administered questionnaire (N = 601). Surveys implemented in Chile and Panama in 2004, followed by northwestern New Mexico in 2008, attempted to assess knowledge and behavior change with respect to hantavirus in high- and lower-risk prevalence areas during endemic periods. While levels of concern over contracting hantavirus were lowest in New Mexico, they were highest in Panama. Respondents in Chile showed mid-level concern and exhibited a tendency to practice proper cleaning methods more than in New Mexico and Panama. This indicates that public health messages appear to be more effective in Chile. However, since negative behavior changes, such as sweeping and vacuuming, occur at some level in all three populations, improved messages should help decrease risk of exposure to HPS.

Wildfires in Chile: A review

Science.gov (United States)

Úbeda, Xavier; Sarricolea, Pablo

2016-11-01

This paper reviews the literature examining the wildfire phenomenon in Chile. Since ancient times, Chile's wildfires have shaped the country's landscape, but today, as in many other parts of the world, the fire regime - pattern, frequency and intensity - has grown at an alarming rate. In 2014, > 8000 fires were responsible for burning c. 130,000 ha, making it the worst year in Chile's recent history. The reasons for this increase appear to be the increment in the area planted with flammable species; the rejection of these landscape modifications on the part of local communities that target these plantations in arson attacks; and, the adoption of intensive forest management practices resulting in the accumulation of a high fuel load. These trends have left many native species in a precarious situation and forest plantation companies under considerable financial pressure. An additional problem is posed by fires at the wildland urban interface (WUI), threatening those inhabitants that live in Chile's most heavily populated cities. The prevalence of natural fires in Chile; the relationship between certain plant species and fire in terms of seed germination strategies and plant adaptation; the relationship between fire and invasive species; and, the need for fire prevention systems and territorial plans that include fire risk assessments are some of the key aspects discussed in this article. Several of the questions raised will require further research, including just how fire-dependent the ecosystems in Chile are, how the forest at the WUI can be better managed to prevent human and material damage, and how best to address the social controversy that pits the Mapuche population against the timber companies.

Productivity and Persistence of Yellow Serradela (Ornithopus compressus L. and Biserrula (Biserrula pelecinus L. in the Mediterranean Climate Region of Central Chile Productividad y Persistencia de Serradela Amarilla (Ornithopus compressus L. y Biserrula (Biserrula pelecinus L. en la Región Climática Mediterránea de Chile Central

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Alejandro del Pozo

2009-09-01

Full Text Available The production and sustainability of non-irrigated pastures in the Mediterranean climate region of central Chile is currently limited by the low diversity of valuable species and cultivars of annual forage legumes, able to persist in zones with highly variable annual rainfall, and low fertility or poorly drained soils. In this work, DM production, seed yield, hardseededness and pasture persistence were evaluated for cultivars of yellow serradella (Ornithopus compressus L. and biserrula (Biserrula pelecinus L., in field experiments conducted in the subhumid portion of the Mediterranean climate region of Chile. Burr medic (Medicago polymorpha L. and sub clover (Trifolium subterraneum L. were used as a reference plants. A remarkable DM production and seed yield were observed in biserrula (cvs. Mor96 and Casbah, and in some cultivars of yellow serradella (e.g. Madeira, Santorini; biserrula produced by far the largest number of seeds per m². As was expected for species that produce very high levels of hard-seeds, the regeneration of biserrula and serradella was low in second growing season, but plant density and productivity were high in the third growing season. The use of biserrula and serradela in monoculture or in mixture with other annual legumes, either in pasture-crop rotation or permanent pasture, would contribute to the improvement of the prevailing productive systems in the Mediterranean climate region of central Chile.La producción y la sostenibilidad de las praderas de secano en la región de clima mediterráneo de Chile central están actualmente limitadas por la baja diversidad de especies valiosas y cultivares de leguminosas forrajeras anuales, capaces de persistir en zonas con precipitaciones anuales sumamente variables, y suelos de baja fertilidad o de mal drenaje. En este trabajo se evaluó la producción de fitomasa, producción de semilla, dureza seminal y la persistencia de cultivares de serradela amarilla (Ornithopus

Testing and Contrasting Road Safety Education, Deterrence, and Social Capital Theories: A Sociological Approach to the Understanding of Male Drink-Driving in Chile's Metropolitan Region.

Science.gov (United States)

Nazif, José Ignacio

2011-01-01

Three theories offer different explanations to the understanding of male drink-driving. In order to test road safety education, deterrence, and social capital theories, logistic regression analysis was applied to predict respondents' statements of having or not having engaged in actual drink-driving (DD). Variable for road safety education theory was whether a driver had graduated from a professional driving school or not. Deterrence theory was operationalized with a variable of whether a driver had been issued a traffic ticket or not. Social capital theory was operationalized with two variables, having children or not and having religion identification or not. Since both variables 'years of formal education' and 'years of driving experience' have been reported to be correlated to alcohol consumption and DD respectively, these were introduced as controls. In order to assess the significance of each variable statistically, Wald tests were applied in seven models. Results indicate on the one hand that road safety education variable is not statistically significant; and on the other, deterrence theory variable and social capital theory variable 'having children' were both statistically significant at the level of .01. Findings are discussed in reference to Chile's context. Data were taken from the "Road Users Attitudes and Behaviors towards Traffic Safety" survey from the National Commission of Road Safety of the Government of Chile (2005). The sample size was reported to be 2,118 (N of male drivers was 396). This survey was representative of Chile's Metropolitan Region road users' population.

Petrology of the Fort Smith - Great Slave Lake radiometric high near Pilot Lake, N.W.T

International Nuclear Information System (INIS)

Burwash, R.A.; Cape, D.F.

1981-01-01

Near Pilot Lake, the east boundary of the Fort Smith - Great Slave Lake radiometric high coincides with the contact of a well-foliated, porphyroblastic microcline-plagioclase-quartz-garnet-biotite gneiss (Pilot Lake Gneiss) with a hybrid assemblage of quartzite, mica schist, garnet-cordierite gneiss, and minor amphibolite (Variable Paragneiss). Anomalously high concentrations of uranium and thorium are associated with mafic-rich, lenticular bodies with a mineral assemblage biotite + monazite + zircon + ilmenite + hematite +- plagioclase +- quartz, within both the Variable Paragneiss and the Pilot Lake Gneiss. Corundum and spinel occur in the mafic lenses and sillimanite, kyanite, and hypersthene in other inclusions of the Pilot Lake Gneiss. The ilmenite-magnetite--monazite-zircon-apatite assemblage is interpreted as a 'black sand' concentration in a clastic sedimentary sequence subsequently metamorphosed by a regional granulite facies event. A granite pluton intruded during the same orogenic cycle assimilated the clastic metasedimentary rocks containing black sand interlayers, becoming enriched in thorium from the monazite. A second metamorphic event at lower P-T conditions, accompanied by strong cataclasis, developed the texture of the Pilot Lake Gneiss as now observed. Shearing within the gneiss locally concentrated hematite + quartz + uranium. Regional tectonic extrapolations suggest that the pyroxene granulite event was Kenoran and the later amphibolite event Hudsonian. (author)

The Licancabur Project: Exploring the Limits of Life in the Highest Lake on Earth as an Analog to Martian Paleolakes

Science.gov (United States)

Cabrol, N. A.; Grin, E. A.; McKay, C. P.; Friedmann, I.; Diaz, G. Chong; Demergasso, C.; Kisse, K.; Grigorszky, I.; Friedmann, R. Ocampo; Hock, A.

2003-01-01

The Licancabur volcano (6017 m) hosts the highest and one of the least explored lakes in the world in its summit crater. It is located 22 deg.50 min. South / 67 deg.53 min. West at the boundary of Chile and Bolivia in the High-Andes. In a freezing environment, the lake located in volcano-tectonic environment combines low-oxygen, low atmospheric pressure due to altitude, and high-UV radiation (see table). However, its bottom water temperature remains above 0 C year-round. These conditions make Licancabur a unique analog to Martian paleolakes considered high-priority sites for the search for life on Mars.

Regional Geomorphological Conditions Related to Recent Changes of Glacial Lakes in the Issyk-Kul Basin, Northern Tien Shan

Directory of Open Access Journals (Sweden)

Mirlan Daiyrov

2018-03-01

either a vanishing or a short-lived type. In this way, the large variability in the number of each lake type and the distribution of types over this four-year period arises from regional geomorphological conditions and not directly from the local short-term summer temperature anomaly and precipitation or glacier recession.

Regional maximum rainfall analysis using L-moments at the Titicaca Lake drainage, Peru

Science.gov (United States)

Fernández-Palomino, Carlos Antonio; Lavado-Casimiro, Waldo Sven

2017-08-01

The present study investigates the application of the index flood L-moments-based regional frequency analysis procedure (RFA-LM) to the annual maximum 24-h rainfall (AM) of 33 rainfall gauge stations (RGs) to estimate rainfall quantiles at the Titicaca Lake drainage (TL). The study region was chosen because it is characterised by common floods that affect agricultural production and infrastructure. First, detailed quality analyses and verification of the RFA-LM assumptions were conducted. For this purpose, different tests for outlier verification, homogeneity, stationarity, and serial independence were employed. Then, the application of RFA-LM procedure allowed us to consider the TL as a single, hydrologically homogeneous region, in terms of its maximum rainfall frequency. That is, this region can be modelled by a generalised normal (GNO) distribution, chosen according to the Z test for goodness-of-fit, L-moments (LM) ratio diagram, and an additional evaluation of the precision of the regional growth curve. Due to the low density of RG in the TL, it was important to produce maps of the AM design quantiles estimated using RFA-LM. Therefore, the ordinary Kriging interpolation (OK) technique was used. These maps will be a useful tool for determining the different AM quantiles at any point of interest for hydrologists in the region.

Holocene evolution of lakes in the forest-tundra biome of northern Manitoba, Canada

Science.gov (United States)

Hobbs, William O.; Edlund, Mark B.; Umbanhowar, Charles E.; Camill, Philip; Lynch, Jason A.; Geiss, Christoph; Stefanova, Vania

2017-03-01

The late-Quaternary paleoenvironmental history of the western Hudson Bay region of Subarctic Canada is poorly constrained. Here, we present a regional overview of the post-glacial history of eight lakes which span the forest-tundra biome in northern Manitoba. We show that during the penultimate drainage phase of Lake Agassiz the lake water had an estimated pH of ∼6.0, with abundant quillwort (Isöetes spp.) along the lakeshore and littoral zone and some floating green algae (Botryococcus spp. and Pediastrum sp.). Based on multiple sediment proxies, modern lake ontogeny in the region commenced at ∼7500 cal yrs BP. Pioneering diatom communities were shaped by the turbid, higher alkalinity lake waters which were influenced by base cation weathering of the surrounding till following Lake Agassiz drainage. By ∼7000 cal yrs BP, soil development and Picea spp. establish and the lakes began a slow trajectory of acidification over the remaining Holocene epoch. The natural acidification of the lakes in this region is slow, on the order of several millennia for one pH unit. Each of the study lakes exhibit relatively stable aquatic communities during the Holocene Thermal Maximum, suggesting this period is a poor analogue for modern climatic changes. During the Neoglacial, the beginning of the post-Little Ice Age period represents the most significant climatic event to impact the lakes of N. Manitoba. In the context of regional lake histories, the rate of diatom floristic change in the last 200-300 years is unprecedented, with the exception of post-glacial lake ontogeny in some of the lakes. For nearly the entire history of the lakes in this region, there is a strong linkage between landscape development and the aquatic ecosystems; however this relationship appears to become decoupled or less strong in the post-LIA period. Significant 20th century changes in the aquatic ecosystem cannot be explained wholly by changes in the terrestrial ecosystem, suggesting that future

Influence of permafrost on lake terraces of Lake Heihai (NE Tibetan Plateau)

Science.gov (United States)

Lockot, Gregori; Hartmann, Kai; Wünnemann, Bernd

2013-04-01

The Tibetan Plateau (TP) is one of the key regions for climatic global change. Besides the poles the TP is the third highest storage of frozen water in glaciers. Here global warming is three times higher than in the rest of the world. Additionally the TP provides water for billions of people and influences the moisture availability from the Indian and East Asian monsoon systems. During the Holocene extent and intensity of the monsoonal systems changed. Hence, in the last decades, a lot of work was done to reconstruct timing and frequency of monsoonal moisture, to understand the past and give a better forecast for the future. Comparative workings often show very heterogeneous patterns of timing and frequency of the Holocene precipitation and temperature maximum, emphasizing the local importance of catchment dynamics. In this study we present first results of lake Heihai (36°N, 93°15'E, 4500m a.s.l.), situated at the north-eastern border of the TP. The lake is surrounded by a broad band of near-shore lake sediments, attesting a larger lake extent in the past. These sediments were uplifted by permafrost, reaching nowadays heights ca. +8 meters above present lake level. Due to the uplift one of the main inflows was blocked and the whole hydrology of the catchment changed. To quantify the uplift of permafrost Hot Spot Analysis were accomplished at a DEM of the near-shore area. As a result regions of high permafrost uplift and those which mirror the original height of lake ground were revealed. The most obvious uplift took place in the northern and western part of the lake, where the four uplift centers are located. In contrast the southern and eastern areas show a rather degraded pattern (probably by fluvial erosion, thermokarst, etc.). The ancient lake bottom, without permafrost uplift was estimated to be 4-6 meters above the modern lake level. For a better understanding of permafrost interaction inside the terrace bodies a 5m sediment profile was sampled and

Value Assessment of Artificial Wetland Derived from Mining Subsided Lake: A Case Study of Jiuli Lake Wetland in Xuzhou

OpenAIRE

Laijian Wang; Lachun Wang; Pengcheng Yin; Haiyang Cui; Longwu Liang; Zhenbo Wang

2017-01-01

Mining subsided lakes are major obstacles for ecological restoration and resource reuse in mining regions. Transforming mining subsided lakes into artificial wetlands is an ecological restoration approach that has been attempted in China in recent years, but a value assessment of the approach still needs systematic research. This paper considers Jiuli Lake wetland, an artificial wetland derived from restoration of a mining subsided lake in plain area, as a case study. A value assessment model...

Impact of Intrathermocline eddies on seamount and oceanic island off Central Chile: Observation and modeling

Science.gov (United States)

Hormazabal, Samuel; Morales, Carmen; Cornejo, Marcela; Bento, Joaquim; Valencia, Luis; Auger, Pierre; Rodriguez, Angel; Correa, Marco; Anabalón, Valeria; Silva, Nelson

2016-04-01

In the Southeast Pacific, oceanographic processes that sustain the biological production necessary to maintain the ecosystems associated to seamounts and oceanic islands are still poorly understood. Recent studies suggest that the interaction of mesoscale and submesoescale eddies with oceanic islands and seamounts could be playing an important role in the time-space variability of primary production. In this work, research cruises, satellite data and Regional Ocean Modeling System (ROMS) results have been used to describe the main characteristics of intrathermocline eddies (ITE) and their impact on the Juan Fernández archipelago (JFA), off central Chile. The JFA is located off the coast of central Chile (33°S), and is composed of three main islands: Robinson Crusoe (RC), Alejandro Selkirk (AS) and Santa Clara (SC). Between the RC and AS are located the westernmost seamounts (JF6 and JF5) of the Juan Fernández archipelago. Satellite altimetry data (sea surface height from AVISO) were used to detect and track mesoscale eddies through eddy-tracking algorithm. Physical, chemical and biological parameters as temperature, salinity, dissolved oxygen and fluorescence were measured in the water column at JF5 and JF6, and along the coast off central Chile (30-40°S). Results from the research cruise exhibit the interaction between an ITE and the seamount JF6. Eddy-tracking results showed that the ITE observed at the JF6 was formed at the coast off central-southern Chile, traveled ~900 km seaward and after ~9 months reached the JF5 and JF6 region. Observations along the Chilean coast confirmed that the coast corresponds to the formation area of the observed ITE. In this region, ITEs are represented by subsurface lenses (~100 km diameter; 400 m thickness) of homogeneous salinity, nutrient rich and oxygen-poor equatorial subsurface water mass (ESSW) which is transported poleward by the Peru-Chile undercurrent in the coastal band and seaward by ITEs. The effect of ITEs on the

Review Article: Lake and breach hazard assessment for moraine-dammed lakes: an example from the Cordillera Blanca (Peru

Directory of Open Access Journals (Sweden)

A. Emmer

2013-06-01

Full Text Available Glacial lake outburst floods (GLOFs and related debris flows represent a significant threat in high mountainous areas across the globe. It is necessary to quantify this threat so as to mitigate their catastrophic effects. Complete GLOF hazard assessment incorporates two phases: the probability of water release from a given glacial lake is estimated through lake and breach hazard assessment while the endangered areas are identified during downstream hazard assessment. This paper outlines a number of methods of lake and breach hazard assessment, which can be grouped into three categories: qualitative, of which we outline eight; semi-quantitative, of which we outline two; and quantitative, of which we outline three. It is considered that five groups of critical parameters are essential for an accurate regionally focused hazard assessment method for moraine-dammed lakes in the Cordillera Blanca. These comprise the possibility of dynamic slope movements into the lake, the possibility of a flood wave from a lake situated upstream, the possibility of dam rupture following a large earthquake, the size of the dam freeboard (or ratio of dam freeboard, and a distinction between natural dams and those with remedial work. It is shown that none of the summarised methods uses all these criteria with, at most, three of the five considered by the outlined methods. A number of these methods were used on six selected moraine-dammed lakes in the Cordillera Blanca: lakes Quitacocha, Checquiacocha, Palcacocha, Llaca, Rajucolta, and Tararhua. The results have been compared and show that each method has certain advantages and disadvantages when used in this region. These methods demonstrate that the most hazardous lake is Lake Palcacocha.

Organochlorine compounds in soils and sediments of the mountain Andean Lakes

International Nuclear Information System (INIS)

Borghini, Francesca; Grimalt, Joan O.; Sanchez-Hernandez, Juan C.; Barra, Ricardo; Garcia, Carlos J. Torres; Focardi, Silvano

2005-01-01

Semi-volatile organochlorine compounds (OC) were analyzed in remote Andean soils and lake sediments. The sampling sites covered a wide latitudinal gradient from 18 deg. S to 46 deg. S along Chile and an altitudinal gradient (10-4500 m). The concentrations were in the order of background levels, involving absence of major pollution sources in the high mountain areas. Significant correlations were found between log-transformed concentrations of hexachlorobenzene, α- and γ-hexachlorocyclohexane in soils and total organic content (TOC). In addition, TOC-normalized concentrations of the most volatile OC showed a significant linear dependence with air temperature. This good agreement points to temperature as a significant factor for the retention of long range transported OC in remote ecosystems such as the Andean mountains, although other variables should not be totally excluded. The highest concentrations of OCs were achieved in the sites located at highest altitude and lowest temperature of the dataset. - Distribution of persistent organochlorine compounds in the Andean Mountain lakes is influenced by temperature

Paleoecology of a Northern Michigan Lake and the relationship among climate, vegetation, and Great Lakes water levels

Science.gov (United States)

Booth, R.K.; Jackson, S.T.; Thompson, T.A.

2002-01-01

We reconstructed Holocene water-level and vegetation dynamics based on pollen and plant macrofossils from a coastal lake in Upper Michigan. Our primary objective was to test the hypothesis that major fluctuations in Great Lakes water levels resulted in part from climatic changes. We also used our data to provide temporal constraints to the mid-Holocene dry period in Upper Michigan. From 9600 to 8600 cal yr B.P. a shallow, lacustrine environment characterized the Mud Lake basin. A Sphagnum-dominated wetland occupied the basin during the mid-Holocene dry period (???8600 to 6600 cal yr B.P.). The basin flooded at 6600 cal yr B.P. as a result of rising water levels associated with the onset of the Nipissing I phase of ancestral Lake Superior. This flooding event occured contemporaneously with a well-documented regional expansion of Tsuga. Betula pollen increased during the Nipissing II phase (4500 cal yr B.P.). Macrofossil evidence from Mud Lake suggests that Betula alleghaniensis expansion was primarily responsible for the rising Betula pollen percentages. Major regional and local vegetational changes were associated with all the major Holocene highstands of the western Great Lakes (Nipissing I, Nipissing II, and Algoma). Traditional interpretations of Great Lakes water-level history should be revised to include a major role of climate. ?? 2002 University of Washington.

The Water Level Fall of Lake Megali Prespa (N Greece): an Indicator of Regional Water Stress Driven by Climate Change and Amplified by Water Extraction?

Science.gov (United States)

van der Schriek, Tim; Giannakopoulos, Christos

2014-05-01

The Mediterranean stands out globally due to its sensitivity to (future) climate change, with future projections predicting an increase in excessive drought events and declining rainfall. Regional freshwater ecosystems are particularly threatened: precipitation decreases, while extreme droughts increase and human impacts intensify (e.g. water extraction, drainage, pollution and dam-building). Many Mediterranean lake-wetland systems have shrunk or disappeared over the past two decades. Protecting the remaining systems is extremely important for supporting global biodiversity and for ensuring sustainable water availability. This protection should be based on a clear understanding of lake-wetland hydrological responses to natural and human-induced changes, which is currently lacking in many parts of the Mediterranean. The interconnected Prespa-Ohrid Lake system is a global hotspot of biodiversity and endemism. The unprecedented fall in water level (~8m) of Lake Megali Prespa threatens this system, but causes remain debated. Modelling suggests that the S Balkan will experience rainfall and runoff decreases of ~30% by 2050. However, projections revealing the potential impact of these changes on future lake level are unavailable as lake regime is not understood. A further drop in lake level may have serious consequences. The Prespa Lakes contribute ~25% of the total inflow into Lake Ohrid through underground karst channels; falling lake levels decrease this discharge. Lake Ohrid, in turn, feeds the Drim River. This entire catchment may therefore be affected by falling lake levels; its water resources are of great importance for Greece, Albania, FYROM and Montenegro (e.g. tourism, agriculture, hydro-energy, urban & industrial use). This new work proves that annual water level fluctuations of Lake Megali Prespa are predominantly related to precipitation during the first 7 months (Oct-Apr) of the hydrological year (Oct-Sep). Lake level is very sensitive to regional and

Chile Energy Policy Review 2009

Energy Technology Data Exchange (ETDEWEB)

NONE

2009-10-22

Since 1990, Chile has been the fastest growing economy in Latin America thanks to sound economic management and integration into the global economy. Chile can also be proud of its energy policy achievements. The pioneering privatisation and liberalisation of its electricity sector in the 1980s was the foundation for a competitive energy sector, which has sustained the rapid growth of the Chilean economy over the past two decades. Nonetheless, Chile faces the continuing challenge of finding additional energy supplies to fuel economic growth. Chile has limited fossil energy resources and depends on imports to meet three-quarters of its energy needs. The country's electricity sector has faced three periods of significant stress over the past decade. The last episode took place in 2007/2008, when the loss of natural gas imports from Argentina was further exacerbated by a drought in the central system, where hydropower normally accounts for over half of electricity generation. Drawing on the experience of IEA member countries, the Review assesses Chile's major energy challenges and provides recommendations. Six main themes emerge: the successful liberalisation of the power sector in the 1980s; the essential role played by the state in ensuring energy security; the re-formulation of Chile's long-term energy policy; the proposed reorganisation of the institutional framework; greater independence for the system operators; and the need for a clear framework of regulation so that long-term investment decisions integrate social and environmental costs. This publication is essential reading for all who are interested in Chilean energy issues and in learning about the important role sound energy policy can play in developing a nation's economic and social welfare.

Vnější ekonomické vztahy Chile

OpenAIRE

Horáková, Anna

2007-01-01

Práce se zabývá vnějšími ekonomickými vztahy Chile. V první části je charakterizována ekonomika Chile. V druhé části je zmapován vývoj obchodní politiky Chile a zapojování Chile do ekonomické integrace. Poslední kapitola nejprve analyzuje vývoj obchodu Chile, ilustruje problém jednostranného zaměření chilského exportu a analyzuje obchodní vztahy s EU, USA a Čínou. Následně jsou naznačeny nové ?role? Chile ve vztahu ke světovému obchodu.

Environmental status of the Lake Michigan region. Volume 14. Birds of the Lake Michigan drainage basin

Energy Technology Data Exchange (ETDEWEB)

Wallace, G.J.

1977-07-01

This report characterizes the bird life found in 100 counties of the four states peripheral to Lake Michigan. It discusses major habitats (the Lake Michigan shoreline, inland lakes, rivers and streams, marshes, fields and open spaces, and woodlots) and associates specific birds with habitats according to preferences for space and food. It also discusses the special attributes of state parks and lakeshores, refuges and sanctuaries, and other special areas which are attractive to avifauna. Patterns of historical occurrence and abundance, and the influence of pesticides and pollution, disease, and hunting pressure are explored to place present occurrence in a modern perspective. Migration patterns are discussed to explain increases and decreases which occur in nonresident avifauna of the Basin. The distribution and habits of birds that occur regularly in the Basin are described in an annotated list; a more complete list is presented in a table which encapsulates data for rapid and convenient reference. Separate sections deal with extinct, extirpated, and introduced species, and with endangered, threatened, and declining species.

EL GÉNERO GLANDULARIA (VERBENACEAE EN CHILE

Directory of Open Access Journals (Sweden)

Nataly O\\u2019Leary

2013-01-01

Full Text Available Se presenta una revisión taxonómica y nomenclatural del género Glandularia para Chile. El género está representado por 12 especies y una variedad, ocho de estos taxones son endémicos de Chile. Las especies se distribuyen desde la zona más septentrional del territorio, región de Arica y Parinacota, hasta la región de Los Lagos, al sur. Sin embargo la mayor diversidad específica se encuentra en las regiones centrales, de Coquimbo, Valparaíso y Metropolitana. Se describen e ilustran cada una de las 12 especies de Glandularia. A su vez, se proponen 14 nuevos sinónimos y tres nuevas combinaciones: Glandularia landbecki, G. multiglandulosa y G. ribifolia; se designan 15 lectotipos para: Erinus laciniatus, Verbena bella, V. berteroi, V. corymbosa, V. foetida, V. gynobasis, V. gynobasis var. strigosa, V. landbeckii, V. lipozygioides, V. multiglandulosa, V. porrigens, V. ribifolia, V. sulphurea var. fuscorubra, V. sulphurea var. pedunculata, y V. trachea; y se postula un neotipo para Verbena paulseni.

[Papillomavirus and cervical cancer in Chile].

Science.gov (United States)

O'Ryan, Miguel; Valenzuela, María Teresa

2008-11-01

Molecular, clinical and epidemiological studies have established beyond doubt that human papiloma viruses (HPV) cause cervical cancer. The virus is also associated with genital warts and other less common cancers in oropharynx, vulva, vagina and penis. Worldwide, VPH genotypes 16 and 18 are the most common high risk genotypes, detected in near 70% of women with cervical cancer. The discovery of a cause-effect relationship between several carcinogenic microorganisms and cancer open avenues for new diagnostic, treatment and prevention strategies. In this issue of Revista Médica de Chile, two papers on HPV are presented. Guzman and colleagues demonstrate that HPV can be detected in 66% to 77% of healthy male adolescents bypolymerase chain reaction and that positivity depends on the site of the penis that is sampled. These results support the role of male to female transmission of high risk HPVs in Chile and should lead to even more active educational campaigns. The second paper provides recommendations for HPV vaccine use in Chile, generated by the Immunization Advisory Committee of the Chilean Infectious Disease Society. To issue these recommendations, the Committee analyzes the epidemiological information available on HPV infection and cervical cancer in Chile, vaccine safety and effectiveness data, and describes cost-effectiveness studies. Taking into account that universal vaccination is controversial, the Committee favors vaccine use in Chile and it's incorporation into a national program. However, there is an indication that the country requires the implementation of an integrated surveillance approach including cross matching of data obtained from HPV genotype surveillance, monitoring of vaccination coverage, and surveillance of cervical cancer. The final decision of universal vaccine use in Chile should be based on a through analysis of information.ev Mid Chile

Chile: Civil-Military Relations and Democratic Consolidation

Science.gov (United States)

1998-12-01

Publishers, 1992), 41. 26 Javier Martinez and Alvaro Diaz , Chile The Great Transformation (Harrisonburg, Virginia: The Brookings Institution, 1996...the world economy, by means of technological advancements, makes it necessary to reduce 32 Javier Martinez and Alvaro Diaz , Chile the Great...disapproves the executive’s budget. There is no 60 Alicia Frohman, "Chile: External Actors and the Transition to Democracy," in Beyond Sovereignty

Source apportionment of PM10 and PM2.5 in a desert region in northern Chile

International Nuclear Information System (INIS)

Jorquera, Héctor; Barraza, Francisco

2013-01-01

Estimating contributions of anthropogenic sources to ambient particulate matter (PM) in desert regions is a challenging issue because wind erosion contributions are ubiquitous, significant and difficult to quantify by using source-oriented, dispersion models. A receptor modeling analysis has been applied to ambient PM 10 and PM 2.5 measured in an industrial zone ∼ 20 km SE of Antofagasta (23.63°S, 70.39°W), a midsize coastal city in northern Chile; the monitoring site is within a desert region that extends from northern Chile to southern Perú. Integrated 24-hour ambient samples of PM 10 and PM 2.5 were taken with Harvard Impactors; samples were analyzed by X Ray Fluorescence, ionic chromatography (NO 3 − and SO 4 = ), atomic absorption (Na + , K + ) and thermal optical transmission for elemental and organic carbon determination. Receptor modeling was carried out using Positive Matrix Factorization (US EPA Version 3.0); sources were identified by looking at specific tracers, tracer ratios, local winds and wind trajectories computed from NOAA's HYSPLIT model. For the PM 2.5 fraction, six contributions were found — cement plant, 33.7 ± 1.3%; soil dust, 22.4 ± 1.6%; sulfates, 17.8 ± 1.7%; mineral stockpiles and brine plant, 12.4 ± 1.2%; Antofagasta, 8.5 ± 1.3% and copper smelter, 5.3 ± 0.8%. For the PM 10 fraction five sources were identified — cement plant, 38.2 ± 1.5%; soil dust, 31.2 ± 2.3%; mineral stockpiles and brine plant, 12.7 ± 1.7%; copper smelter, 11.5 ± 1.6% and marine aerosol, 6.5 ± 2.4%. Therefore local sources contribute to ambient PM concentrations more than distant sources (Antofagasta, marine aerosol) do. Soil dust is enriched with deposition of marine aerosol and calcium, sulfates and heavy metals from surrounding industrial activities. The mean contribution of suspended soil dust to PM 10 is 50 μg/m 3 and the peak daily value is 104 μg/m 3 . For the PM 2.5 fraction, suspended soil dust contributes with an average of 9.3 �

Zahraničně obchodní politika Chile

OpenAIRE

Horáková, Anna

2009-01-01

The Diploma thesis focuses on foreign trade policy of Chile. The first part is a brief summary of socio-economic characteristics of the country. The following section deals with the individual strategies in the approach to foreign trade policy applied in Chile since independence to the present. It exams the determinants of changes in foreign trade policy of Chile and monitors changes in territorial and commodity structure of the foreign trade of Chile. In the final section assesses the curren...

Water Services in Chile : Comparing Private and Public Performance

OpenAIRE

Bitrán, Gabriel A.; Valenzuela, Eduardo P.

2003-01-01

In 1988, Chile put in place a new regulatory regime for water and sanitation, allowing rates to reflect the actual cost of providing services. The government then reorganized the sector under 13 state-owned regional water companies and, in 1998, started to partially privatize some of them. Four years after the first sale, it is now possible to assess the early results of privatization. Thi...

Primary Medical Care in Chile

DEFF Research Database (Denmark)

Scarpaci, Joseph L.

Primary medical care in Chile: accessibility under military rule [Front Cover] [Front Matter] [Title Page] Contents Tables Figures Preface Chapter 1: Introduction Chapter 2: The Restructuring of Medical Care Financing in Chile Chapter 3: Inflation and Medical Care Accessibility Chapter 4: Help......-Seeking Behavior of the Urban Poor Chapter 5: Spatial Organization and Medical Care Accessibility Chapter 6: Conclusion...

Copper Bioleaching in Chile

OpenAIRE

Juan Carlos Gentina; Fernando Acevedo

2016-01-01

Chile has a great tradition of producing and exporting copper. Over the last several decades, it has become the first producer on an international level. Its copper reserves are also the most important on the planet. However, after years of mineral exploitation, the ease of extracting copper oxides and ore copper content has diminished. To keep the production level high, the introduction of new technologies has become necessary. One that has been successful is bioleaching. Chile had the first...

The relation between Puelche wind and the occurrence of forest fires in Bio Bio region, Chile

International Nuclear Information System (INIS)

Inzunza, Juan Carlos

2009-01-01

This paper presents a study of the relation between Puelche wind and forest fires in the Bio Bio Region, Chile. To establish a relationship between Puelche wind and forest fire generation, different data analysis methods and statistics test were applied. The relation between the total number of fires in the season and the days with Puelche wind were not statistically significant. When analyzing daily averages of fires produced with and without Puelche wind for each season, the highest daily fire occurrence values were found when there is Puelche wind, indicating that this event produces a strong effect on the daily occurrence of fires since these increased by 90% in comparison to the days without Puelche wind. The results of the difference between the number of fires with and without Puelche wind with respect to the average number of total fires indicate that the days with Puelche wind surpass both the total and the average values for days without Puelche wind, confirming the strong effect that a Puelche wind day has on forest fires. The greatest number of fires produced with Puelche wind occurs in the Province of Concepcion. This Province is the most affected by Puelche wind conditions despite having the smallest surface area for the region studied. Still, it is the most populous province of the region and has the greatest surface area with forests and plantations with respect to its size. Consequently, Puelche wind is a factor that increases the occurrence of forest fires and favors their propagation.

Habitat capacity for cougar recolonization in the Upper Great Lakes region.

Science.gov (United States)

O Neil, Shawn T; Rahn, Kasey C; Bump, Joseph K

2014-01-01

Recent findings indicate that cougars (Puma concolor) are expanding their range into the midwestern United States. Confirmed reports of cougar in Michigan, Minnesota, and Wisconsin have increased dramatically in frequency during the last five years, leading to speculation that cougars may re-establish in the Upper Great Lakes (UGL) region, USA. Recent work showed favorable cougar habitat in northeastern Minnesota, suggesting that the northern forested regions of Michigan and Wisconsin may have similar potential. Recolonization of cougars in the UGL states would have important ecological, social, and political impacts that will require effective management. Using Geographic Information Systems (GIS), we extended a cougar habitat model to Michigan and Wisconsin and incorporated primary prey densities to estimate the capacity of the region to support cougars. Results suggest that approximately 39% (>58,000 km2) of the study area could support cougars, and that there is potential for a population of approximately 500 or more animals. An exploratory validation of this habitat model revealed strong association with 58 verified cougar locations occurring in the study area between 2008 and 2013. Spatially explicit information derived from this study could potentially lead to estimation of a viable population, delineation of possible cougar-human conflict areas, and the targeting of site locations for current monitoring. Understanding predator-prey interactions, interspecific competition, and human-wildlife relationships is becoming increasingly critical as top carnivores continue to recolonize the UGL region.

Habitat capacity for cougar recolonization in the Upper Great Lakes region.

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Shawn T O Neil

Full Text Available BACKGROUND: Recent findings indicate that cougars (Puma concolor are expanding their range into the midwestern United States. Confirmed reports of cougar in Michigan, Minnesota, and Wisconsin have increased dramatically in frequency during the last five years, leading to speculation that cougars may re-establish in the Upper Great Lakes (UGL region, USA. Recent work showed favorable cougar habitat in northeastern Minnesota, suggesting that the northern forested regions of Michigan and Wisconsin may have similar potential. Recolonization of cougars in the UGL states would have important ecological, social, and political impacts that will require effective management. METHODOLOGY/PRINCIPAL FINDINGS: Using Geographic Information Systems (GIS, we extended a cougar habitat model to Michigan and Wisconsin and incorporated primary prey densities to estimate the capacity of the region to support cougars. Results suggest that approximately 39% (>58,000 km2 of the study area could support cougars, and that there is potential for a population of approximately 500 or more animals. An exploratory validation of this habitat model revealed strong association with 58 verified cougar locations occurring in the study area between 2008 and 2013. CONCLUSIONS/SIGNIFICANCE: Spatially explicit information derived from this study could potentially lead to estimation of a viable population, delineation of possible cougar-human conflict areas, and the targeting of site locations for current monitoring. Understanding predator-prey interactions, interspecific competition, and human-wildlife relationships is becoming increasingly critical as top carnivores continue to recolonize the UGL region.

Average niche breadths of species in lake macrophyte communities respond to ecological gradients variably in four regions on two continents.

Science.gov (United States)

Alahuhta, Janne; Virtala, Antti; Hjort, Jan; Ecke, Frauke; Johnson, Lucinda B; Sass, Laura; Heino, Jani

2017-05-01

Different species' niche breadths in relation to ecological gradients are infrequently examined within the same study and, moreover, species niche breadths have rarely been averaged to account for variation in entire ecological communities. We investigated how average environmental niche breadths (climate, water quality and climate-water quality niches) in aquatic macrophyte communities are related to ecological gradients (latitude, longitude, altitude, species richness and lake area) among four distinct regions (Finland, Sweden and US states of Minnesota and Wisconsin) on two continents. We found that correlations between the three different measures of average niche breadths and ecological gradients varied considerably among the study regions, with average climate and average water quality niche breadth models often showing opposite trends. However, consistent patterns were also found, such as widening of average climate niche breadths and narrowing of average water quality niche breadths of aquatic macrophytes along increasing latitudinal and altitudinal gradients. This result suggests that macrophyte species are generalists in relation to temperature variations at higher latitudes and altitudes, whereas species in southern, lowland lakes are more specialised. In contrast, aquatic macrophytes growing in more southern nutrient-rich lakes were generalists in relation to water quality, while specialist species are adapted to low-productivity conditions and are found in highland lakes. Our results emphasise that species niche breadths should not be studied using only coarse-scale data of species distributions and corresponding environmental conditions, but that investigations on different kinds of niche breadths (e.g., climate vs. local niches) also require finer resolution data at broad spatial extents.

[Land Use Pattern Change and Regional Sustainability Evaluation of Wetland in Jiaogang Lake].

Science.gov (United States)

Yang, Yang; Cai, Yi-min; Bai, Yan-ying; Chen, Wei-ping; Yang, Xiu-chao

2015-06-01

Changes in land use and sustainability evaluation of wetland in Jiaogang Lake from 1995 to 2013 were analyzed, based on the land use change models and an index system, supported by RS, GIS, and social statistical data. The results showed: (1) dry land, paddy field, and building land were the predominant landscape in the study area. The arable land was mainly converted during 1995-2000, which was driven by the extension of agriculture, and the building land increased significantly during 2010-2013, which was driven by the tourism development. (2) Compared to the beginning research area, the building land increased by 123.3%, and the wetland decreased by 23.15%. The land system was at risk for a low proportion of wetland, scarcity of unused land, and the fragmented landscape. (3) The regional sustainability results were bad level, bad level, poor level, good level, and poor level during the different periods, with some room for improvement. (4) The fitness of regional sustainability in study area yielded satisfactory results in 2010, owing to the rapid growth of regional productivity and the regional stability. Since 2010, with the increasing environmental load, the regional sustainability fell down to the poor level. The obstruction of sustainable development is necessary to be addressed in the study area.

Is Lake Chabot Eutrophic?

Science.gov (United States)

Pellegrini, K.; Logan, J.; Esterlis, P.; Lew, A.; Nguyen, M.

2013-12-01

Introduction/Abstract: Lake Chabot is an integral part of the East Bay watershed that provides habitats for animals and recreation for humans year-round. Lake Chabot has been in danger of eutrophication due to excessive dumping of phosphorous and nitrogen into the water from the fertilizers of nearby golf courses and neighboring houses. If the lake turned out to be eutrophified, it could seriously impact what is currently the standby emergency water supply for many Castro Valley residents. Eutrophication is the excessive richness of nutrients such as nitrogen and phosphorus in a lake, usually as a result of runoff. This buildup of nutrients causes algal blooms. The algae uses up most of the oxygen in the water, and when it dies, it causes the lake to hypoxify. The fish in the lake can't breathe, and consequently suffocate. Other oxygen-dependant aquatic creatures die off as well. Needless to say, the eutrophication of a lake is bad news for the wildlife that lives in or around it. The level of eutrophication in our area in Northern California tends to increase during the late spring/early summer months, so our crew went out and took samples of Lake Chabot on June 2. We focused on the area of the lake where the water enters, known on the map as Honker Bay. We also took readings a ways down in deeper water for comparison's sake. Visually, the lake looked in bad shape. The water was a murky green that glimmered with particulate matter that swirled around the boat as we went by. In the Honker Bay region where we focused our testing, there were reeds bathed in algae that coated the surface of the lake in thick, swirling patterns. Surprisingly enough, however, our test results didn't reveal any extreme levels of phosphorous or nitrogen. They were slightly higher than usual, but not by any significant amount. The levels we found were high enough to stimulate plant and algae growth and promote eutrophication, but not enough to do any severe damage. After a briefing with a

Hot emission model for mobile sources: application to the metropolitan region of the city of Santiago, Chile.

Science.gov (United States)

Corvalán, Roberto M; Osses, Mauricio; Urrutia, Cristian M

2002-02-01

Depending on the final application, several methodologies for traffic emission estimation have been developed. Emission estimation based on total miles traveled or other average factors is a sufficient approach only for extended areas such as national or worldwide areas. For road emission control and strategies design, microscale analysis based on real-world emission estimations is often required. This involves actual driving behavior and emission factors of the local vehicle fleet under study. This paper reports on a microscale model for hot road emissions and its application to the metropolitan region of the city of Santiago, Chile. The methodology considers the street-by-street hot emission estimation with its temporal and spatial distribution. The input data come from experimental emission factors based on local driving patterns and traffic surveys of traffic flows for different vehicle categories. The methodology developed is able to estimate hourly hot road CO, total unburned hydrocarbons (THCs), particulate matter (PM), and NO(x) emissions for predefined day types and vehicle categories.

A Systematic Study of Zerbar Lake Restoration

Science.gov (United States)

Hosseini, Reza; Oveis Torabi, Seyed; Forman Asgharzadeh, Deonna

2017-04-01

The beautiful lake of Zerbar, located near Marivan City at the west of Iran, is a freshwater lake with an area of 20 km2 and average depth of 5 meters. The lake is created by regional tectonic activities and is mainly fed with natural spring water from bottom. During the past three decades, regional development has caused much disturbance to the natural environment of the lake and its watershed. Rescuing the lake is crucial to the sustainability of the whole region. The study of Zerbar Restoration was performed with the aim to restore its health indicators. Variety of human activities in the watershed, as well as the multidisciplinary nature of lake restoration studies, made it necessary to develop a systematic approach to conduct the study. In Step I of restoration studies, satellite images were investigated to identify the historical changes of watershed during the past 30 years. Meanwhile, documents since 50 years ago were studied. Results indicate that farmland and graze land areas have been relatively constant during the past 50 years. Also, the area of lake, its riparian canes and floating plants have not changed much. In fact, the only significant land use change observed was the significant spread of Marivan City that has stretched toward the lake. The main physical variation to the lake has been elevating the southern edge of the lake by a constructing a landfill dam which was done to control the lake's overflow discharge for irrigation of downstream farmland development. Step II consists of studies performed by disciplines of water resources, hydrogeology, water quality, wetland and watershed ecology, agriculture, animal farming and fishery. Study results indicate that eutrophication (TSL>100), mainly caused by sewage from Marivan City and the surrounding rural areas has been the main reason for lake ecosystem degradation. DPSIR framework, as a novel approach in lake restoration, was applied to synthesize the study results of different disciplines in a

Social-Ecological Thresholds in a Changing Boreal Landscape: Insights from Cree Knowledge of the Lesser Slave Lake Region of Alberta, Canada

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Brenda L. Parlee

2012-06-01

Full Text Available Drawing on the traditional ecological knowledge (TEK of the Lesser Slave Lake Cree, this paper shares understanding of how resource development has affected water, fish, forests, and wildlife as well as the well-being of Cree communities in the Lesser Slave Lake region of Alberta, Canada. In addition to descriptive observations of change, the narratives point to social-ecological thresholds or tipping points in the relationship of Cree harvesters to local lands and resources. Specifically, the study speaks to the echoing effects of ecological loss and degradation on traditional livelihood practices over the last 100 years highlighting the complexity of cumulative effects as well as the challenges of balancing resource development in the region with alternative land uses including those valued by Alberta's Aboriginal peoples.

Land Use and Land Cover Change in the Qinghai Lake Region of the Tibetan Plateau and Its Impact on Ecosystem Services

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Jian Gong

2017-07-01

Full Text Available Exploration of land use and land cover change (LULCC and its impacts on ecosystem services in Tibetan plateau is valuable for landscape and environmental conservation. In this study, we conduct spatial analysis on empirical land use and land cover data in the Qinghai Lake region for 1990, 2000, and 2010 and simulate land cover patterns for 2020. We then evaluate the impacts of LULCC on ecosystem service value (ESV, and analyze the sensitivity of ESV to LULCC to identify the ecologically sensitive area. Our results indicate that, from 1990 to 2010, the area of forest and grassland increased while the area of unused land decreased. Simulation results suggest that the area of grassland and forest will continue to increase and the area of cropland and unused land will decrease for 2010–2020. The ESV in the study area increased from 694.50 billion Yuan in 1990 to 714.28 billion Yuan in 2000, and to 696.72 billion Yuan in 2020. Hydrology regulation and waste treatment are the top two ecosystem services in this region. The towns surrounding the Qinghai Lake have high ESVs, especially in the north of the Qinghai Lake. The towns with high ESV sensitivity to LULCC are located in the northwest, while the towns in the north of the Qinghai Lake experienced substantial increase in sensitivity index from 2000–2010 to 2010–2020, especially for three regulation services and aesthetic landscape provision services.

Characteristics of petroleum contaminants and their distribution in Lake Taihu, China.

Science.gov (United States)

Guo, Jixiang; Fang, Jia; Cao, Jingjing

2012-08-31

Taihu Lake is a typical plain eutrophic shallow lake. With rapidly economic development of the lake area, the petroleum products and oil wastewater produced in various processes have been inevitably discharged into Taihu Lake. As the major fresh water resource in the economically developed region of Yangtze River Delta, the water quality and environmental condition of Taihu Lake have the direct bearing on the natural environment and sustainable development of economy in this region. For this reason we carried out the study to explore the composition, distribution characteristics and sources of petroleum contaminants in Taihu Lake. The aim of this study was to provide the basis for standard management and pollution control of the Taihu Lake environment. The result showed that water samples from near industrial locations were of relatively higher petroleum contaminants concentrations. The oil pollutants concentrations in different areas of Lake Taihu ranged from 0.106 mg/L to 1.168 mg/L, and the sequence of total contents distribution characteristics of petroleum pollutants from high to low in different regions of Taihu Lake was: "Dapu", "Xiaomeikou", "Zhushan Bay", "Lake center", "Qidu". The results showed that total concentrations of n-alkanes and PAHs ranged from 0.045 to 0.281 mg/L and from 0.011 to 0.034 mg/L respectively. In the same region, the concentrations of hydrocarbon pollutants in the surface and bottom of the lake were higher than that in the middle. This paper reached a conclusion that the petroleum contaminants in Taihu Lake mainly derived from petroleum pollution caused by human activities as indicated by OEP, bimodal distribution, CPI, Pr/Ph ratio, the LMW/HMW ratio and other evaluation indices for sources of n-alkanes and polycyclic aromatic hydrocarbons (PAHs).

Radiological protection in interventional cardiology in Chile

International Nuclear Information System (INIS)

Ramirez, A.; Leyton, F.A.; Farias, E.; Silva, A.M.; Vano, E.; Oyarzun, C.; Gamarra, J.; Ortiz, P.

2001-01-01

In September 2000, an expert mission was assigned to Chile, under the regional project named 'International BBS in Medical Practices Radiation Protection and Quality Assurance In Interventional Radiology' (ARCAL XLIX). The objective of the mission was to evaluate the level of radiation protection (RP) and safety in interventional cardiology ( IC ) installations. A team of local cardiologists, medical physicists and technologists was created for this purpose and during one week, several cardiology laboratories were evaluated and some basic quality controls (QC) were carried out. A basic pilot training course in radiation protection was imparted at the Hospital of the University of Chile in Santiago de Chile and some of the key objectives for a future national quality assurance programme were presented during the national congress of IC. In addition, a national survey on radiation protection aspects was circulated and its results evaluated. These activities enabled the local team to become familiar with the methodology of assessment of the level of protection and the organization of a programme, which was illustrated with the examples of similar European programmes. As result of these actions, several proposals were made to both the local authorities and the IAEA. The most important were: a) to initiate a basic QC programme, b) to organize a training in RP for cardiologists in order to formalize their accreditation, c) to improve personal occupational dosimetry, d) to initiate a programme of patient dosimetry, e) to optimize the technical and clinical protocols, f) to create a national registry of incidents with skin injuries. (author)

76 FR 23276 - Lake Tahoe Basin Federal Advisory Committee (LTFAC)

Science.gov (United States)

2011-04-26

... Interagency Partnership on the Lake Tahoe Region and other matters raised by the Secretary. DATES: The meeting... preliminary recommendation of Lake Tahoe Southern Nevada Public Land Management Act (SNPLMA) Round 12 capital... Lake Tahoe SNPLMA Round 12 capital projects and science themes, and 3) public comment. All Lake Tahoe...

Chile; Staff Report for the 2003 Article IV Consultation

OpenAIRE

International Monetary Fund

2003-01-01

Chile has successfully resisted contagion from neighboring countries difficulties. Chile's inflation targeting framework has successfully anchored inflation expectations and increased the economy's resilience to external shocks while maintaining price stability. The floating exchange rate regime is an essential part of the macroeconomic policy framework and continues to serve Chile well. The interest in recapitalizing the central bank is welcomed. Executive Directors commend Chile for the tra...

Patterns of turnover and floristic similarity show a non-random distribution of naturalized flora in Chile, South America Patrones de recambio y similitud florística muestran una distribución no aleatoria de la flora naturalizada en Chile, Sudamérica

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SERGIO A CASTRO

2008-03-01

Full Text Available The current geographical distribution of alien species could be informative of processes involved in the biological invasions facilitated by humans. Because environmental and anthropic factors affect the geographic distribution of alien plants, we hypothesize that naturalized plants have a non-random distribution along extensive geographical ranges. On the basis of a complete and updated database of naturalized plants in Chile, we analyzed their turnover and floristic similarities among regions that encompass a wide latitudinal gradient in South America. Using Moran's index and Mantel's test we characterized the spatial auto-correlation (regional aggregation and the effect of geographical distance on the index values. Additionally, we used clustering methods and resampling procedures to detect plant assemblages at regional level. Whittaker's index displayed a positive tilt, increasing according to geographical distance and reaching a plateau; conversely, Jaccard's index was negatively associated with geographical distance. Removing the effect of distance, both Whittaker's and Jaccard's values showed no significant trends. Multivariate analysis combined with resampling procedures revealed the existence of three distinctive plant clusters: Northernmost Chile, Central-southern Chile, and Southernmost Chile. These clusters are characterized by naturalized plants that are not present in the others. Based on this evidence, we conclude that the set of naturalized plants in Chile exhibits a non-random geographical distribution, displaying an ordered geographical pattern across regions (latitude. We discuss the role of the environmental variables (climate, latitude and land use post-European colonization as factors in the distributional patterns here documentedLa distribución geográfica actual de especies exóticas puede ser informativa de los procesos involucrados en las invasiones biológicas facilitadas por humanos. Debido a que los factores

Environmental and spatial factors influencing the distribution of cladocerans in lakes across the central Canadian Arctic treeline region

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John P. SMOL

2010-02-01

Full Text Available We examine the role of local environmental and spatial factors in explaining variation in the composition of cladoceran assemblages from surface sediments within a set of 50 lakes spanning a broad southwest to northeast transect across the central Canadian Arctic treeline region from Yellowknife (Northwest Territories to the northern boundary of the Thelon Game Sanctuary (Nunavut Territory. Within each lake, the cladoceran fauna was identified based on the subfossil exoskeletal remains preserved in recently deposited lake sediments. Physical and chemical limnological data were measured in August of 1996 and 1998. Spatial data were generated based on latitude and longitude using Principal Coordinates of Neighbors Matrices analysis (PCNM. The relationships between cladocerans and the measured environmental and spatial variables were examined using both unconstrained (Principal Components Analysis, PCA and constrained (Redundancy Analysis, RDA ordination techniques. Variance partitioning, based on partial RDAs, was used to identify the relative importance of significant environmental and spatial explanatory variables. Three environmental variables were identified as significantly influencing cladoceran community structure: surface water temperature, dissolved organic carbon (DOC, and total phosphorus (TP. Five PCNM-generated spatial variables were also significant in explaining cladoceran distributions. Variance partitioning attributed 14% of the variance in the distribution of Cladocera to spatial factors, an additional 10% to spatially-structured environmental variables, and 8% to environmental factors that were not spatially-structured. Within the central Canadian Arctic treeline region, spatial and other environmental processes had an important influence on the distribution of cladoceran communities. The strong influence of spatial factors was related to the large ecoclimatic gradient across treeline. The distribution patterns of cladocerans

[Spatial distribution of COD and the correlations with other parameters in the northern region of Lake Taihu].

Science.gov (United States)

Zhang, Yun-lin; Yang, Long-yuan; Qin, Bo-qiang; Gao, Guang; Luo, Lian-cong; Zhu, Guang-wei; Liu, Ming-liang

2008-06-01

Spatial variation of chemical oxygen demand (COD) concentration was documented and significant correlations between COD concentration and chromophoric dissolved organic matter (CDOM) absorption, fluorescence, DOC concentration were found based on a cruise sampling in the northern region of Lake Taihu in summer including 42 samplings. The possible source of COD was also discussed using every two cruise samplings in summer and winter, respectively. The COD concentration ranged from 3.77 to 7.96 mg x L(-1) with a mean value of (5.90 +/- 1.54) mg x L(-1). The mean COD concentrations in Meiliang Bay and the central lake basin were (6.93 +/- 0.89) mg x L(-1) and (4.21 +/- 0.49) mg x L(-1) respectively. A significant spatial difference was found between Meiliang Bay and the central lake basin in COD concentration, CDOM absorption coefficient, fluorescence, DOC and phytoplankton pigment concentrations, decreasing from the river mouth to inner bay, outer bay and the central lake basin. Significant correlations between COD concentration and CDOM absorption, fluorescence, DOC concentration, suggested that COD concentration could be estimated and organic pollution could be assessed using CDOM absorption retrieved from remote sensing images. Significant and positive correlation was found between COD concentration and chlorophyll a concentration in summer. However, the correlation was weak or no correlation was found in winter. Furthermore, a significant higher COD concentration was found in summer than in winter (p summer, except for river terrestrial input.

A 60-year record of 129I in Taal Lake sediments (Philippines): Influence of human nuclear activities at low latitude region

DEFF Research Database (Denmark)

Zhang, Luyuan; Hou, Xiaolin; Li, Hong-chun

2017-01-01

in the Taal Lake core appears to be the signal of the Chernobyl accident in 1986. In addition, volcanic activities are reflected in the iodine isotope profiles in the sediment core, suggesting the potential of using iodine isotopes as an indicator of volcanic eruptions.......The influence of human nuclear activities on environmental radioactivity is not well known at low latitude region that are distant from nuclear tests sites and nuclear facilities. A sediment core collected from Taal Lake in the central Philippines was analyzed for 129I and 127I to investigate...

Lake and lake-related drainage area parameters for site investigation program

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