Land subsidence and earth fissures in south-central and southern Arizona, USA

Science.gov (United States)

Conway, Brian D.

2016-05-01

Land subsidence due to groundwater overdraft has been an ongoing problem in south-central and southern Arizona (USA) since the 1940s. The first earth fissure attributed to excessive groundwater withdrawal was discovered in the early 1950s near Picacho. In some areas of the state, groundwater-level declines of more than 150 m have resulted in extensive land subsidence and earth fissuring. Land subsidence in excess of 5.7 m has been documented in both western metropolitan Phoenix and Eloy. The Arizona Department of Water Resources (ADWR) has been monitoring land subsidence since 2002 using interferometric synthetic aperture radar (InSAR) and since 1998 using a global navigation satellite system (GNSS). The ADWR InSAR program has identified more than 25 individual land subsidence features that cover an area of more than 7,300 km2. Using InSAR data in conjunction with groundwater-level datasets, ADWR is able to monitor land subsidence areas as well as identify areas that may require additional monitoring. One area of particular concern is the Willcox groundwater basin in southeastern Arizona, which is the focus of this paper. The area is experiencing rapid groundwater declines, as much as 32.1 m during 2005-2014 (the largest land subsidence rate in Arizona State—up to 12 cm/year), and a large number of earth fissures. The declining groundwater levels in Arizona are a challenge for both future groundwater availability and mitigating land subsidence associated with these declines. ADWR's InSAR program will continue to be a critical tool for monitoring land subsidence due to excessive groundwater withdrawal.

24 CFR 983.54 - Prohibition of assistance for units in subsidized housing.

Science.gov (United States)

2010-04-01

..., DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT PROJECT-BASED VOUCHER (PBV) PROGRAM Selection of PBV Owner... PBV assistance to units in any of the following types of subsidized housing: (a) A public housing... operating costs of the housing; (e) A unit subsidized with Section 236 rental assistance payments (12 U.S.C...

Towards a global land subsidence map

NARCIS (Netherlands)

Erkens, G.; Sutanudjaja, E. H.

2015-01-01

Land subsidence is a global problem, but a global land subsidence map is not available yet. Such map is crucial to raise global awareness of land subsidence, as land subsidence causes extensive damage (probably in the order of billions of dollars annually). With the global land subsidence map

Adaptation and mitigation of land subsidence in Semarang

Science.gov (United States)

Andreas, Heri; Abidin, Hasanuddin Z.; Gumilar, Irwan; Sidiq, Teguh Purnama; Yuwono, Bambang

2017-07-01

Land subsidence is not a new phenomenon for Semarang. Some report said the subsidence in Semarang probably is occurring for more than 100 years. Based on the leveling surveys conducted by the Centre of Environmental Geology from 1999 to 2003 it was found that relatively large subsidence was detected around Semarang Harbor, Pondok Hasanuddin, Bandar Harjo and around Semarang Tawang Railway station, with the rates ranging from 1 to 17 cm/year. Results derived from GPS show that land subsidence in Semarang has spatial and temporal variations. In general, subsidence rates in Semarang have an average rate of about 6 to 7 cm/year, with maximum rates that can go up to 14-19 cm/year at certain locations. The impact of land subsidence in Semarang can be seen in several forms, such as the wider expansion of (coastal) flooding areas "rob", cracking of buildings and infrastructure, and increased inland sea water intrusion. It also badly influences the quality and amenity of the living environment and life (e.g. health and sanitation condition) in the affected areas. In the case of Semarang, adaptation and mitigation are considered very important. We have been done some investigations to this area by field observations (mapping the flooded area, mapping the infrastructure problems, interviewing people and seeing the adaptations, conduct GPS measurement to see deformation, etc.), gather information from Government, from digital media, etc., and we noticed people increased their house, and the local goverment elevated the road and the bridge, etc. regulary over less decade periode as part of adaptation. We also noticed the Central Goverment built the dyke and pumping station. Our conclusions said that the adaptation only made temporaly since significant land subsidence keep coming and worsening by the sea level which is keep rising. Another conclusion, so far we have seen lack of mitigation program, monitoring or even inevective mitigation in Semarang related to this subsidence

Pengaruh Land Subsidence terhadap Genangan Banjir dan Rob di Semarang Timur

Directory of Open Access Journals (Sweden)

ratih Pujiastuti

2016-06-01

Full Text Available Inundation of flood and rob (flood due to high tides in Semarang City is increase wtithin area and depth. It be more seroius condition because of land subsisdence that happened in coastal area of Semarang City. This research is foccused on prediction and mapping of inundation flood and rob due to land subsidence effect in East Semarang, especially Tenggang Watershed and Sringin Watershed. On this research, data analysis including analysis of land subsidence, analysis of hydrological data, analysis of flood discharge with HEC-HMS, hydraulics analysis with HEC-RAS and then mapping the results of the flood inundation with Arc GIS. The inundation will be create with overlay the DEM of flood water level and DEM of topographic. According to the results of analysis is known that minimum land subsidence is 0 cm/year that happened in south area of Semarang and more higher ini north area with maximum land subsidence is 5.58 cm/year. On periode   2014-2031, the contribute of land subsidence to increase the inundation of flood and rob is 1.39%/year.

Innovative repair of subsidence damage

International Nuclear Information System (INIS)

Marino, G.G.

1992-01-01

In order to improve handling of subsidence damages the Illinois Mine Subsidence Insurance Fund supported the development of novel cost-effective methods of repair. The research in developing the repairs was directed towards the most common and costly damages that had been observed. As a result repair techniques were designed for structurally cracked foundations in the tension zone; structurally cracked foundations in the compression zone; and damaged or undamaged tilted foundations. When appropriate the postulated methods would result in: 1. significant cost savings (over conventional procedures); 2. a structural capacity greater than when the foundation was uncracked; and 3. an aesthetic appeal. All the postulated repair methodologies were laboratory and/or field tested. This paper will summarize the essentials of each technique developed and the test results

Working to Reduce Poverty: A National Subsidized Employment Proposal

Directory of Open Access Journals (Sweden)

Indivar Dutta-Gupta

2018-02-01

Full Text Available Subsidized employment programs that increase labor supply and demand are a proven, underutilized strategy for reducing poverty in the short and long term. These programs use public and private funds to provide workers wage-paying jobs, training, and wraparound services to foster greater labor force attachment while offsetting employers’ cost for wages, on-the-job training, and overhead. This article proposes two new separate but harmonized federal funding streams for subsidized employment that would expand automatically when and where economic conditions deteriorate. Participating states and local organizations would be offered generous matching funds to target adult workers most in need and to secure employer participation. The proposal would effectively reduce poverty among workers during work placements, and improve long-term unsubsidized employment and other outcomes for participants and their families.

Assessing the Land Subsidence Governance in Ningbo City: By a Close Study of the Building Collapse at the Strictly Protected Land Subsidence Area

Science.gov (United States)

Yu, Xia

2016-04-01

Ningbo is a coastal city in East China, its land subsidence problem was noticed in the 1960s. However, scientific management was insufficient at that time, so with the fast city development from the 1980s, groundwater was used by a large amount of small factories, and tall buildings were built on the land. It was in 2008, scientists predicted that if without doing anything to prevent the land from subsiding, the city will be covered by the East Sea in 2030. From then on, the local government implied several policies, such as shut down most of the groundwater pumping wells, set up a new authority to enhance the cooperation among different administration departments, and also set up a land subsidence monitoring center for the city. Recently, it is declared that a Stereo regulatory system of land subsidence governance has been achieved. However, in 2012, a 23-years old building in the city center collapsed. According to the City Planning 2009, this building is located just in the strictly protected land subsidence area. The experts, however, think that land subsidence is not the main reason, since there are many illegal changes to the building during the past 23 years. The aim of my research is to assess the land subsidence governance in Ningbo city. I studied the collapsed building, how it was built, what has changed after building, how the environment changed in this area, and how this area became the strictly protected land subsidence area, and what kind of protections have been made. Actually, during the case study I discuss the land subsidence governance design of Ningbo, and to see what practices and lessons we can learn from this case.

Investigation of subsidence event over multiple seam mining area

International Nuclear Information System (INIS)

Kohli, K.K.

1999-01-01

An investigation was performed to determine the sequence of events which caused the 1987 surface subsidence and related damage to several homes in Walker County, Alabama, USA. Surface affects compared to mine maps indicated the subsidence to be mine related. However, two coal seams had been worked under this area. The upper seam, the American seam, ranged from 250 to 280 feet beneath the surface in the area in question. It was mined-out before 1955 by room-and-pillar method leaving in place narrow-long pillars to support the overburden strata, and abandoned in 1955. The lower seam, the Mary Lee seam, ranged from 650 to 700 feet beneath the surface. The Mary Lee seam had been abandoned in 1966 and subsequently became flooded. The dewatering of the Mary Lee seam workings in 1985 caused the submerged pillars to be exposed to the atmosphere. Due to multiple seam mining and the fact that workings had been inundated then dewatered, a subsurface investigation ensued to determine the sequence and ultimate cause of surface subsidence. Core sample tests with fracture analysis in conjunction with down-the-hole TV camera inspections provided necessary information to determine that the subsidence started in the lower seam and progressed through the upper coal seam to the surface. Evidence from the investigation program established that dewatering of the lower seam workings caused the marginally stable support pillars and the roof to collapse. This failure triggered additional subsidence in the upper seam which broadened the area of influence at the surface

Modeling agricultural impacts of longwall mine subsidence: A GIS approach

International Nuclear Information System (INIS)

Darmody, R.G.; Vance, S.L.

1994-01-01

Illinois is both a major agricultural State and one of the leading coal-producing States. The future of coal mining in Illinois is longwall mining. One of the advantages of longwall mining, and the most noticeable consequence, is immediate subsidence. Mitigation of subsidence effects is the responsibility of the coal company. Research has shown that mitigation is usually effective, but may be difficult in many cases. Minimizing subsidence impact by avoiding sensitive soils in the mine plan is a possibility that should be considered. Predicting agricultural impacts of subsidence would give mine designers and regulating agencies an additional tool to use when evaluating mine plans. This paper reports on the development and an application of a predictive model of agricultural soil subsidence sensitivity (SSS). The SSS model involves integration of selected soil properties in a GIS (geographical information system) to assign a subsidence sensitivity class to a given area. Predicted crop yield losses at a proposed longwall mine in southern Illinois, using corn (Zea mays L.) as a reference, were 6.8% for the longwall panel area but ranged from 4.1% to 9.5% for the individual panels. The model also predicted that mitigation of the affected areas would reduce yield losses to 1.2% for the longwall area and to 0.5% to 1.7% for the individual panels

Subsidence caused by an underground nuclear explosion

Energy Technology Data Exchange (ETDEWEB)

Hakala, W W [Environmental Research Corp., Alexandria, VA (United States)

1970-05-15

An underground nuclear detonation creates a cavity, which may be followed by the formation of a rubble chimney and possibly by a surface subsidence crater. A knowledge of the mechanisms of surface and subsurface subsidence is valuable not only because of the potential engineering uses of the chimneys and craters that may form, but also for the prevention of surface damage. Some of the parameters that are of interest in the subsidence phenomenon are the height and volume of the chimney, the porosity of the chimney, the crater size (depth and radius) and shape, and the time required after detonation for formation of the chimney or crater. The influence of the properties of the subsidence medium on the geometry of the subsidence crater must be considered. The conditions under which partial or complete subsidence is prevented must also be studied. The applicability of the relations that have been developed for the flow of bulk solids for relatively small masses and low pressures to the subsidence problem associated with nuclear explosions is examined. Rational modifications are made to describe the subsidence problem. Sensitivity of the subsidence parameters to material properties and the prevailing geometry is shown. Comparison with observed results at the Nevada Test Site is made and the variations encountered are found to be within reasonable limits. The chimney size and subsidence crater dimensions are found to be a function of the bulking characteristics of the medium, the strength parameters, the dimensions of the subsurface cavity, and the depth of the cavity. The great influence of the strength parameters on the collapse times is shown. For a given medium, the prevention of subsidence is dependent on the cavity size. (author)

Spatial Analysis of Land Subsidence and Flood Pattern Based on DInSAR Method in Sentinel Sar Imagery and Weighting Method in Geo-Hazard Parameters Combination in North Jakarta Region

Science.gov (United States)

Prasetyo, Y.; Yuwono, B. D.; Ramadhanis, Z.

2018-02-01

The reclamation program carried out in most cities in North Jakarta is directly adjacent to the Jakarta Bay. Beside this program, the density of population and development center in North Jakarta office has increased the need for underground water excessively. As a result of these things, land subsidence in North Jakarta area is relatively high and so intense. The research methodology was developed based on the method of remote sensing and geographic information systems, expected to describe the spatial correlation between the land subsidence and flood phenomenon in North Jakarta. The DInSAR (Differential Interferometric Synthetic Aperture Radar) method with satellite image data Radar (SAR Sentinel 1A) for the years 2015 to 2016 acquisitions was used in this research. It is intended to obtain a pattern of land subsidence in North Jakarta and then combined with flood patterns. For the preparation of flood threat zoning pattern, this research has been modeling in spatial technique based on a weighted parameter of rainfall, elevation, flood zones and land use. In the final result, we have obtained a flood hazard zonation models then do the overlap against DInSAR processing results. As a result of the research, Geo-hazard modelling has a variety results as: 81% of flood threat zones consist of rural area, 12% consists of un-built areas and 7% consists of water areas. Furthermore, the correlation of land subsidence to flood risk zone is divided into three levels of suitability with 74% in high class, 22% in medium class and 4% in low class. For the result of spatial correlation area between land subsidence and flood risk zone are 77% detected in rural area, 17% detected in un-built area and 6% detected in a water area. Whereas the research product is the geo-hazard maps in North Jakarta as the basis of the spatial correlation analysis between the land subsidence and flooding phenomena.double point.

Data Acquisition for Land Subsidence Control

Science.gov (United States)

Zhu, Y.; Balke, K.

2009-12-01

For controlling land subsidence caused by groundwater over-exploitation, loading of engineered structures, mining and other anthropogenic activities in this fast changing world, a large variety of different data of various scales of concerning areas are needed for scientific study and administrative operational purposes. The economical, social and environmental impacts of anthropogenic land subsidence have long been recognized by many scientific institutions and management authorities based on results of monitoring and analysis at an interdisciplinary level. The land subsidence information systems composed of the surface and subsurface monitoring nets (monitoring and development wells, GPS stations and other facilities) and local data processing centers as a system management tool in Shanghai City was started with the use of GPS technology to monitor land subsidence in 1998. After years of experiences with a set of initiatives by adopting adequate countermeasures, the particular attention given to new improved methodologies to monitor and model the process of land subsidence in a simple and timely way, this is going to be promoted in the whole Yangtze River Delta region in China, where land subsidence expands in the entire region of urban cluster. The Delta land subsidence monitoring network construction aims to establish an efficient and coordinated water resource management system. The land subsidence monitoring network records "living history" of land subsidence, produces detailed scheduled reports and environmental impact statements. For the different areas with local factors and site characteristics, parallel packages need to be designed for predicting changes, land sensitivity and uncertainty analysis, especially for the risk analysis in the rapid growth of megacities and urban areas. In such cases, the new models with new types of local data and the new ways of data acquisition provide the best information for the decision makers for their mitigating

Geospatial subsidence hazard modelling at Sterkfontein Caves ...

African Journals Online (AJOL)

The geo-hazard subsidence model includes historic subsidence occurrances, terrain (water flow) and water accumulation. Water accumulating on the surface will percolate and reduce the strength of the soil mass, possibly inducing subsidence. Areas for further geotechnical investigation are identified, demonstrating that a ...

The Research on Subsidence Prediction of Soils Around Deep Foundation Pit

Directory of Open Access Journals (Sweden)

Ge LIU

2014-12-01

Full Text Available Deep foundation pit will cause settlement of surround buildings in the process of excavation. When the settlement is excessive, it will give rise to safety issues. Subsidence monitoring has become an important measure to ensure the safety of deep foundation pits. But in current subsidence monitoring engineering, the costs of wiring, unwiring and installation are particularly high. This paper proposes a portable wireless data transmission device in forecasting and early warning of settlement deformation of soils around deep foundation pits. We solve the problem by adopting the means of wireless communication to replace the cable transmission link part. The device does not rely on any personal computers. Instead, it can directly deal with the collected data through grey prediction GM (1, 1 mathematical model, neural network and interpolation model to give short-term, medium- term and long-term forecasts, respectively. Additionally it is able to set a threshold value. Once the forecast data reach the threshold, the device can issue alert and achieve the target of reminding technicians, so as to provide reliable basis to prevent and reduce disasters.

THE CORRELATION ANALYSIS OF SUBSIDENCE MONITORING BY D-INSAR AND THE CHANGE OF URBAN CONSTRUCTION LAND

Directory of Open Access Journals (Sweden)

K. J. Yang

2017-05-01

Full Text Available The change of urban construction land affect the subsidence directly or indirectly, the method of D-InSAR has centimeter level or even millimeter accuracy that can provide a reliable and accurate data for the research of correlation analysis of subsidence monitoring by D-InSAR and the change of urban construction land. This article takes Guiyang, Nanning city as example, using 3m level TerraSAR data to construct the Subsidence model by interferometric measurement, then compared with the Chinese national land use change remote sensing survey database at the same measure time to have a correlation analysis GIS research between subsidence and the change of urban construction land. The results shows that the integral correlation coefficient achieved 0.78 between subsidence and the change of urban construction land, the major construction area and the high density construction area are with severe land subsidence. In addition, the correlation coefficient increased from the main city to the suburbs, indicates that some of the main city causes permanent settlement and is difficult to recover. It also shows that some area subsidence caused by long-term mining or other natural factors has no strong correlation with the change of urban construction land, therefore, the results of D-InSAR subsidence monitoring have a reaction on urban construction planning, guiding urban planning to high stability, low settlement area.

Gulf Coast geopressured-geothermal program summary report compilation. Volume 2-B: Resource description, program history, wells tested, university and company based research, site restoration

Energy Technology Data Exchange (ETDEWEB)

John, C.J.; Maciasz, G.; Harder, B.J.

1998-06-01

The US Department of Energy established a geopressured-geothermal energy program in the mid 1970`s as one response to America`s need to develop alternate energy resources in view of the increasing dependence on imported fossil fuel energy. This program continued for 17 years and approximately two hundred million dollars were expended for various types of research and well testing to thoroughly investigate this alternative energy source. This volume describes the following studies: Design well program; LaFourche Crossing; MG-T/DOE Amoco Fee No. 1 (Sweet Lake); Environmental monitoring at Sweet Lake; Air quality; Water quality; Microseismic monitoring; Subsidence; Dow/DOE L.R. Sweezy No. 1 well; Reservoir testing; Environmental monitoring at Parcperdue; Air monitoring; Water runoff; Groundwater; Microseismic events; Subsidence; Environmental consideration at site; Gladys McCall No. 1 well; Test results of Gladys McCall; Hydrocarbons in production gas and brine; Environmental monitoring at the Gladys McCall site; Pleasant Bayou No. 2 well; Pleasant Bayou hybrid power system; Environmental monitoring at Pleasant Bayou; and Plug abandonment and well site restoration of three geopressured-geothermal test sites. 197 figs., 64 tabs.

September 2016 Bayou Choctaw Subsidence Report

Energy Technology Data Exchange (ETDEWEB)

Moriarty, Dylan Michael [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Lord, Anna C. Snider [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2017-05-01

Subsidence monitoring is a crucial component to understanding cavern integrity of salt storage caverns. This report looks at historical and current data at the Bayou Choctaw Strategic Petroleum Reserve Site. Data from the most recent land-based annual surveys, GPS, and tiltmeter indicate the subsidence rates across the site are approximately 0.0 ft./yr. Because of this, there is no evidence from the subsidence survey to suggest any of the DOE caverns have been structurally compromised.

Monitoring Subsidence in California with InSAR

Science.gov (United States)

Farr, T. G.; Jones, C. E.; Liu, Z.; Neff, K. L.; Gurrola, E. M.; Manipon, G.

2016-12-01

Subsidence caused by groundwater pumping in the rich agricultural area of California's Central Valley has been a problem for decades. Over the last few years, interferometric synthetic aperture radar (InSAR) observations from satellite and aircraft platforms have been used to produce maps of subsidence with cm accuracy. We are continuing work reported previously, using ESA's Sentinel-1 to extend our maps of subsidence in time and space, in order to eventually cover all of California. The amount of data to be processed has expanded exponentially in the course of our work and we are now transitioning to the use of the ARIA project at JPL to produce the time series. ARIA processing employs large Amazon cloud instances to process single or multiple frames each, scaling from one to many (20+) instances working in parallel to meet the demand (700 GB InSAR products within 3 hours). The data are stored in Amazon long-term storage and an http view of the products are available for users of the ARIA system to download the products. Higher resolution InSAR data were also acquired along the California Aqueduct by the NASA UAVSAR from 2013 - 2016. Using multiple scenes acquired by these systems, we are able to produce time series of subsidence at selected locations and transects showing how subsidence varies both spatially and temporally. The maps show that subsidence is continuing in areas with a history of subsidence and that the rates and areas affected have increased due to increased groundwater extraction during the extended western US drought. Our maps also identify and quantify new, localized areas of accelerated subsidence. The California Department of Water Resources (DWR) funded this work to provide the background and an update on subsidence in the Central Valley to support future policy. Geographic Information System (GIS) files are being furnished to DWR for further analysis of the 4 dimensional subsidence time-series maps. Part of this work was carried out at the

A Picture of Subsidized Households 2009

Data.gov (United States)

Department of Housing and Urban Development — Picture of Subsidized Households describes the nearly 5 million households living in HUD-subsidized housing in the United States for the year 2009. Picture 2009...

A Picture of Subsidized Housholds 2008

Data.gov (United States)

Department of Housing and Urban Development — Picture of Subsidized Households describes the nearly 5 million households living in HUD-subsidized housing in the United States for the year 2008. Picture 2008...

Impact of coal mining subsidence on farmland in eastern China

International Nuclear Information System (INIS)

Hu, Z.; Hu, F.; Li, J.; Li, H.

1997-01-01

This paper discusses damage characteristics of farmland due to coal mining subsidence in eastern China. The landscape of the mining subsidence trough has been divided into three zones; central zone, trough margin zone an dinner-edge zone. Each zone had a specific characteristic of deformation. The water accumulation, prone (downward sloping) land and fissures are typical damage characteristics of the subsidence landscape in eastern China. Based on soils analysis at different positions of the subsidence trough, the impact of mining subsidence on soil properties was identified. The physical properties of soil sensitive to mining subsidence were bulk density, water content and hydraulic conductivity, and they showed worsening form the top to the centre of the subsidence trough. Except for soil electrical conductivity, the tested soil chemical properties were not so sensitive to mining subsidence. They may however change after subsidence. An accumulation of salt was found in both new and old subsidence areas and the old subsidence area had a higher salt content. The soil biomass C in newly subsided land showed a decreasing trend from the top to the centre of the subsidence trough, but no obvious trend was observed in the old subsidence areas. Based on the soil analysis of subsided land, soil erosion was identified as a serious problem, most severe in the middle of the prone land. 4 refs., 5 figs., 1 tab

General program of energy research: innovation in hard coal, 1974-1977. New drivage systems. Rahmenprogramm energieforschung: innovation steinkohle, 1974-1977. Neue vortriebssysteme. Volume 1, Part 1

Energy Technology Data Exchange (ETDEWEB)

1979-01-01

During the four year period of the program, initiated by the German Federal government, 19 research and machine development projects in the field of road heading machines were subsidized. The Juelich energy research project management oversaw the progress of the programs. Projects for developing new machines at a total cost of 0.1 to 3.2 million DM per project were subsidized by 50%. The developed machinery includes the Roboter, WAV 200 and AM 50 high powered road cutter loaders, HSV 4 and Hausherr Mini ripper hydraulic percussion hammer heading machines, the DEMAG/SVM full face tunneling machine with a cutting head of 6 m in diameter, efficient drilling and blasting equipment for road drivage in rock and mechanized systems for achieving efficient support work, and keeping pace with the speed of mine drivage.

Subsidence monitoring system for offshore applications: technology scouting and feasibility studies

Directory of Open Access Journals (Sweden)

R. Miandro

2015-11-01

Full Text Available Because of concern about possible impacts of hydrocarbon production activities on coastal-area environments and infrastructures, new hydrocarbon offshore development projects in Italy must submit a monitoring plan to Italian authorities to measure and analyse real-time subsidence evolution. The general geological context, where the main offshore Adriatic fields are located, is represented by young unconsolidated terrigenous sediments. In such geological environments, sea floor subsidence, caused by hydrocarbon extraction, is quite probable. Though many tools are available for subsidence monitoring onshore, few are available for offshore monitoring. To fill the gap ENI (Ente Nazionale Idrocarburi started a research program, principally in collaboration with three companies, to generate a monitoring system tool to measure seafloor subsidence. The tool, according to ENI design technical-specification, would be a robust long pipeline or cable, with a variable or constant outside diameter (less than or equal to 100 mm and interval spaced measuring points. The design specifications for the first prototype were: to detect 1 mm altitude variation, to work up to 100 m water depth and investigation length of 3 km. Advanced feasibility studies have been carried out with: Fugro Geoservices B.V. (Netherlands, D'Appolonia (Italy, Agisco (Italy. Five design (using three fundamental measurements concepts and five measurement tools were explored: cable shape changes measured by cable strain using fiber optics (Fugro; cable inclination measured using tiltmeters (D'Appolonia and measured using fiber optics (Fugro; and internal cable altitude-dependent pressure changes measured using fiber optics (Fugro and measured using pressure transducers at discrete intervals along the hydraulic system (Agisco. Each design tool was analysed and a rank ordering of preferences was performed. The third method (measurement of pressure changes, with the solution proposed by Agisco

Subsidence monitoring system for offshore applications: technology scouting and feasibility studies

Science.gov (United States)

Miandro, R.; Dacome, C.; Mosconi, A.; Roncari, G.

2015-11-01

Because of concern about possible impacts of hydrocarbon production activities on coastal-area environments and infrastructures, new hydrocarbon offshore development projects in Italy must submit a monitoring plan to Italian authorities to measure and analyse real-time subsidence evolution. The general geological context, where the main offshore Adriatic fields are located, is represented by young unconsolidated terrigenous sediments. In such geological environments, sea floor subsidence, caused by hydrocarbon extraction, is quite probable. Though many tools are available for subsidence monitoring onshore, few are available for offshore monitoring. To fill the gap ENI (Ente Nazionale Idrocarburi) started a research program, principally in collaboration with three companies, to generate a monitoring system tool to measure seafloor subsidence. The tool, according to ENI design technical-specification, would be a robust long pipeline or cable, with a variable or constant outside diameter (less than or equal to 100 mm) and interval spaced measuring points. The design specifications for the first prototype were: to detect 1 mm altitude variation, to work up to 100 m water depth and investigation length of 3 km. Advanced feasibility studies have been carried out with: Fugro Geoservices B.V. (Netherlands), D'Appolonia (Italy), Agisco (Italy). Five design (using three fundamental measurements concepts and five measurement tools) were explored: cable shape changes measured by cable strain using fiber optics (Fugro); cable inclination measured using tiltmeters (D'Appolonia) and measured using fiber optics (Fugro); and internal cable altitude-dependent pressure changes measured using fiber optics (Fugro) and measured using pressure transducers at discrete intervals along the hydraulic system (Agisco). Each design tool was analysed and a rank ordering of preferences was performed. The third method (measurement of pressure changes), with the solution proposed by Agisco, was

Analysis of geodetic surveying on the margin of subsidence depression

Czech Academy of Sciences Publication Activity Database

Doležalová, Hana; Müller, Karel; Bláha, P.

-, č. 273 (2006), s. 103-112 ISSN 0372-9508 Institutional research plan: CEZ:AV0Z30860518 Keywords : subsidence depression * levelling * height changes Subject RIV: DE - Earth Magnetism, Geodesy, Geography

Family Home Childcare Providers: A Comparison of Subsidized and Non-Subsidized Working Environments and Employee Issues

Science.gov (United States)

Shriner, Michael; Schlee, Bethanne M.; Mullis, Ronald L.; Cornille, Thomas A.; Mullis, Ann K.

2008-01-01

Federal and State Governments provide childcare subsidies for low-income working families. This study compares the encountered issues and working environments of family home providers of subsidized and non-subsidized childcare. Questionnaires were distributed throughout a southeastern state in the United States to 548 family home childcare…

An Analysis Model for Water Cone Subsidence in Bottom Water Drive Reservoirs

Science.gov (United States)

Wang, Jianjun; Xu, Hui; Wu, Shucheng; Yang, Chao; Kong, lingxiao; Zeng, Baoquan; Xu, Haixia; Qu, Tailai

2017-12-01

Water coning in bottom water drive reservoirs, which will result in earlier water breakthrough, rapid increase in water cut and low recovery level, has drawn tremendous attention in petroleum engineering field. As one simple and effective method to inhibit bottom water coning, shut-in coning control is usually preferred in oilfield to control the water cone and furthermore to enhance economic performance. However, most of the water coning researchers just have been done on investigation of the coning behavior as it grows up, the reported studies for water cone subsidence are very scarce. The goal of this work is to present an analytical model for water cone subsidence to analyze the subsidence of water cone when the well shut in. Based on Dupuit critical oil production rate formula, an analytical model is developed to estimate the initial water cone shape at the point of critical drawdown. Then, with the initial water cone shape equation, we propose an analysis model for water cone subsidence in bottom water reservoir reservoirs. Model analysis and several sensitivity studies are conducted. This work presents accurate and fast analytical model to perform the water cone subsidence in bottom water drive reservoirs. To consider the recent interests in development of bottom drive reservoirs, our approach provides a promising technique for better understanding the subsidence of water cone.

The Opportunity Illusion: Subsidized Housing and Failing Schools in California

Science.gov (United States)

Pfeiffer, Deirdre

2009-01-01

Since the late 1980s, the Low-Income Housing Tax Credit (LIHTC) program has funded the bulk of subsidized development nationwide, enabling the construction of over 100,000 units targeted to lower income households in California alone (California Tax Credit Allocation Committee 2009c). Yet, by not encouraging the siting of projects in racially…

Ensemble of ground subsidence hazard maps using fuzzy logic

Science.gov (United States)

Park, Inhye; Lee, Jiyeong; Saro, Lee

2014-06-01

Hazard maps of ground subsidence around abandoned underground coal mines (AUCMs) in Samcheok, Korea, were constructed using fuzzy ensemble techniques and a geographical information system (GIS). To evaluate the factors related to ground subsidence, a spatial database was constructed from topographic, geologic, mine tunnel, land use, groundwater, and ground subsidence maps. Spatial data, topography, geology, and various ground-engineering data for the subsidence area were collected and compiled in a database for mapping ground-subsidence hazard (GSH). The subsidence area was randomly split 70/30 for training and validation of the models. The relationships between the detected ground-subsidence area and the factors were identified and quantified by frequency ratio (FR), logistic regression (LR) and artificial neural network (ANN) models. The relationships were used as factor ratings in the overlay analysis to create ground-subsidence hazard indexes and maps. The three GSH maps were then used as new input factors and integrated using fuzzy-ensemble methods to make better hazard maps. All of the hazard maps were validated by comparison with known subsidence areas that were not used directly in the analysis. As the result, the ensemble model was found to be more effective in terms of prediction accuracy than the individual model.

Subsidence of Surtsey volcano, 1967-1991

Science.gov (United States)

Moore, J.G.; Jakobsson, S.; Holmjarn, J.

1992-01-01

The Surtsey marine volcano was built on the southern insular shelf of Iceland, along the seaward extension of the east volcanic zone, during episodic explosive and effusive activity from 1963 to 1967. A 1600-m-long, east-west line of 42 bench marks was established across the island shortly after volcanic activity stopped. From 1967 to 1991 a series of leveling surveys measured the relative elevation of the original bench marks, as well as additional bench marks installed in 1979, 1982 and 1985. Concurrent measurements were made of water levels in a pit dug on the north coast, in a drill hole, and along the coastline exposed to the open ocean. These surveys indicate that the dominant vertical movement of Surtsey is a general subsidence of about 1.1??0.3 m during the 24-year period of observations. The rate of subsidence decreased from 15-20 cm/year for 1967-1968 to 1-2 cm/year in 1991. Greatest subsidence is centered about the eastern vent area. Through 1970, subsidence was locally greatest where the lava plain is thinnest, adjacent to the flanks of the eastern tephra cone. From 1982 onward, the region closest to the hydrothermal zone, which is best developed in the vicinity of the eastern vent, began showing less subsidence relative to the rest of the surveyed bench marks. The general subsidence of the island probably results from compaction of the volcanic material comprising Surtsey, compaction of the sea-floor sediments underlying the island, and possibly downwarping of the lithosphere due to the laod of Surtsey. The more localized early downwarping near the eastern tephra cone is apparently due to greater compaction of tephra relative to lava. The later diminished local subsidence near the hydrothermal zone is probably due to a minor volume increase caused by hydrous alteration of glassy tephra. However, this volume increase is concentrated at depth beneath the bottom of the 176-m-deep cased drillhole. ?? 1992 Springer-Verlag.

Increasing Access to Subsidized Artemisinin-based Combination Therapy through Accredited Drug Dispensing Outlets in Tanzania

Directory of Open Access Journals (Sweden)

Gabra Michael

2011-06-01

Full Text Available Abstract Background In Tanzania, many people seek malaria treatment from retail drug sellers. The National Malaria Control Program identified the accredited drug dispensing outlet (ADDO program as a private sector mechanism to supplement the distribution of subsidized artemisinin-based combination therapies (ACTs from public facilities and increase access to the first-line antimalarial in rural and underserved areas. The ADDO program strengthens private sector pharmaceutical services by improving regulatory and supervisory support, dispenser training, and record keeping practices. Methods The government's pilot program made subsidized ACTs available through ADDOs in 10 districts in the Morogoro and Ruvuma regions, covering about 2.9 million people. The program established a supply of subsidized ACTs, created a price system with a cost recovery plan, developed a plan to distribute the subsidized products to the ADDOs, trained dispensers, and strengthened the adverse drug reactions reporting system. As part of the evaluation, 448 ADDO dispensers brought their records to central locations for analysis, representing nearly 70% of ADDOs operating in the two regions. ADDO drug register data were available from July 2007-June 2008 for Morogoro and from July 2007-September 2008 for Ruvuma. This intervention was implemented from 2007-2008. Results During the pilot, over 300,000 people received treatment for malaria at the 448 ADDOs. The percentage of ADDOs that dispensed at least one course of ACT rose from 26.2% during July-September 2007 to 72.6% during April-June 2008. The number of malaria patients treated with ACTs gradually increased after the start of the pilot, while the use of non-ACT antimalarials declined; ACTs went from 3% of all antimalarials sold in July 2007 to 26% in June 2008. District-specific data showed substantial variation among the districts in ACT uptake through ADDOs, ranging from ACTs representing 10% of all antimalarial sales

Impact of global change on ground subsidence related to aquifer exploitation. The case of the Vega de Granada aquifer (SE Spain)

Science.gov (United States)

Pulido-Velazquez, David; María Mateos, Rosa; Rueda, Ramon; Pegalajar-Cuellar, Manuel; Ezquerro, Pablo; Béjar, Marta; Herrera, Gerardo; Collados-Lara, Antonio-Juan

2017-04-01

In this research, we intend to develop a methodology to assess the impact of potential global change scenarios on land subsidence. Subsidence rates in wide areas could be estimated by using remote sensing techniques, such as DInSAR and specifically the new radar information obtained by the Sentinel set of satellites from the European Space Agency (ESA). A symbolic regression method will be developed to obtain an explicit quantitative relationship between subsidence, hydraulic head changes and other physical variables (e.g. percentage of clay and silt in the ground, load of buildings and constructions, fill-in works etc.). Different ensemble and downscaling techniques will be used to define potential future global change scenarios for the test-regions based on the data coming from simulations with different Regional Circulation Models (RCMs). Future drawdowns can be estimated from these global change scenarios under different management options. The regression approach will be employed to simulate the impacts of these drawdowns, in terms of land-subsidence, taking into account the estimated hydraulic head changes. It will allow to assess sustainable management of detrital aquifers taking into account subsidence issues. Classic regression analysis attempts to postulate a hypothesis function f, and the regression is reduced to the problem of finding the optimal parameters w of the hypothesis y=f(x, w), to explain a set of dependent variables y from the values of independent variables x, where x and y are known input/output data. Symbolic regression generalizes this process by assuming that f is also unknown in advance, so that the problem is formulated as finding the optimal analytical expression and its parameters that best approximate the data y considering the data in x. To achieve that purpose, in this work Straight Line Programs (SLP) will be used to represent analytical expressions, and a genetic programming approach will be used to find an optimal SLP that

Design and analysis of government subsidized collection systems for incentive-dependent returns

NARCIS (Netherlands)

Aksen, D.; Aras, N.; Karaarslan, A.G.

2009-01-01

We present and solve two bilevel programming (BP) models describing the subsidization agreement between the government and a company engaged in collection and recovery operations. These enable the company to capture the remaining value in cores, referring to used products of different quality types.

Space geodesy: subsidence and flooding in New Orleans.

Science.gov (United States)

Dixon, Timothy H; Amelung, Falk; Ferretti, Alessandro; Novali, Fabrizio; Rocca, Fabio; Dokka, Roy; Sella, Giovanni; Kim, Sang-Wan; Wdowinski, Shimon; Whitman, Dean

2006-06-01

It has long been recognized that New Orleans is subsiding and is therefore susceptible to catastrophic flooding. Here we present a new subsidence map for the city, generated from space-based synthetic-aperture radar measurements, which reveals that parts of New Orleans underwent rapid subsidence in the three years before Hurricane Katrina struck in August 2005. One such area is next to the Mississippi River-Gulf Outlet (MRGO) canal, where levees failed during the peak storm surge: the map indicates that this weakness could be explained by subsidence of a metre or more since their construction.

Preliminary reports on fiscal 2000 results of project for subsidizing international joint research; 2000 nendo kokusai kyodo kenkyu josei jigyo seika hokoku kai yokoshu

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-12-01

This paper presents preliminary reports on fiscal 2000 results of project for subsidizing international joint research sponsored by NEDO. For international joint research teams doing excellent studies, their research expenses are subsidized, thereby promoting international research exchange, enhancing international level of industrial technology and contributing to the formation of basis for innovative industrial technology. The projects relating to the global environmental field are implemented jointly with RITE. The contents of the report to be published are, in the global environmental field (practicability study), development of oil substitute resources, reproducible resources, and technologies for producing polymeric and plastic materials benign to the earth by microorganism using carbon dioxide. In the substance/material field, the contents of the report are innovative production and device application of tunable photonic crystals using electronic penetration network; development of new synthesis process of innovative nitride, creation and theoretical calculation of electromagnetic function; studies on quantum transportation in superconductor and semiconductor bonding structures; and studies on quantum liquid and solid, and application to materials science and technology. (NEDO)

Flooding and subsidence in the Thames Gateway: impact on insurance loss potential

Science.gov (United States)

Royse, Katherine; Horn, Diane; Eldridge, Jillian; Barker, Karen

2010-05-01

and sediment, or rehydration of sediment under flood water. The latter mechanism may be particularly critical on sites where Holocene sediments are currently protected from flooding and are no longer subsiding. Holocene deposits tend to compress, either under their own weight or under a superimposed load such as made ground, built structures or flood water. If protected dry sediments become flooded in the future, subsidence would be expected to resume. This research project aims to investigate the correlation between flood hazards and subsidence hazards and the effect that these two sources of risk will have on insurance losses in the Thames Gateway. In particular, the research will explore the potential hydrological and geophysical drivers and links between flood and subsidence events within the Thames Gateway, assessing the potential for significant event occurrence within the timescales relevant to insurers. In the first part of the project we have identified flood risk areas within the Thames Gateway development zone which have a high risk of flooding and may be affected by renewed or increased subsidence. This has been achieved through the use of national and local-scale 2D and 3D geo-environmental information such as the Geosure dataset (e.g. swell-shrink, collapsible and compressible deposits data layers), PSI data, thickness of superficial and artificial land deposits, and flood potential data etc. In the second stage of the project we will investigate the hydrological and geophysical links between flooding and subsidence events on developed sites; quantify the insurance loss potential in the Thames Gateway from correlated flooding and subsidence events; consider how climate change will affect risk to developments in the Thames Gateway in the context of subsidence and flooding; and develop new ways of communicating and visualise correlated flood and subsidence risk to a range of stakeholders, including the insurance industry, planners, policy makers and the

30 CFR 817.121 - Subsidence control.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Subsidence control. 817.121 Section 817.121... ACTIVITIES § 817.121 Subsidence control. (a) Measures to prevent or minimize damage. (1) The permittee must... control plan prepared pursuant to § 784.20 of this chapter. (c) Repair of damage—(1) Repair of damage to...

River Delta Subsidence Measured with Interferometric Synthetic Aperture Radar (InSAR)

Science.gov (United States)

Higgins, Stephanie

This thesis addresses the need for high-resolution subsidence maps of major world river deltas. Driven by a combination of rising water, sediment compaction, and reduced sediment supply due to damming and flood control, many deltas are sinking relative to sea level. A lack of data constraining rates and patterns of subsidence has made it difficult to determine the relative contributions of each factor in any given delta, however, or to assess whether the primary drivers of land subsidence are natural or anthropogenic. In recent years, Interferometric Synthetic Aperture Radar (InSAR) has emerged as a satellite-based technique that can map ground deformation with mm-scale accuracy over thousands of square kilometers. These maps could provide critical insight into the drivers of subsidence in deltas, but InSAR is not typically applied to non-urban delta areas due to the difficulties of performing the technique in wet, vegetated settings. This thesis addresses those difficulties and achieves high-resolution measurements of ground deformation in rural deltaic areas. Chapter 1 introduces the processes that drive relative sea level rise in river deltas and investigates open questions in delta subsidence research. Chapter 2 assesses the performance of InSAR in delta settings and reviews interferogram generation in the context of delta analysis, presenting delta-specific processing details and guiding interpretation in these challenging areas. Chapter 3 applies Differential (D-) InSAR to the coast of the Yellow River Delta in China. Results show that subsidence rates are as high as 250 mm/y due to groundwater extraction at aquaculture facilities, a rate that exceeds local and global average sea level rise by nearly two orders of magnitude and suggests a significant hazard for Asian megadeltas. Chapter 4 applies interferometric stacking and Small Baseline Subset (SBAS)-InSAR to the Ganges-Brahmaputra Delta, Bangladesh. Results show that stratigraphy controls subsidence in

How to deal with subsidence in the Dutch delta?

NARCIS (Netherlands)

Stouthamer, E.; Erkens, G.

2017-01-01

In many deltas worldwide subsidence still is an underestimated problem, while the threat posed by land subsidence low-lying urbanizing and urbanized deltas exceeds the threat of sea-level rise induced by climate change. Human-induced subsidence is driven by the extraction of hydrocarbons and

The effective subsidence capacity concept: How to assure that subsidence in the Wadden Sea remains within defined limits?

NARCIS (Netherlands)

Waal, J.A. de; Roest,J.P.A.; Fokker, P.A.; Kroon, I.C.; Breunese, J.N.; Muntendam-Bos, A.G.; Oost, P.A.; Wirdum, G. van

2012-01-01

Subsidence caused by extraction of hydrocarbons and solution salt mining is a sensitive issue in the Netherlands. An extensive legal, technical and organisational framework is in place to ensure a high probability that such subsidence will stay within predefined limits. The key question is: how much

Resistivity changes of rock massif on the margin of subsidence depression

Czech Academy of Sciences Publication Activity Database

Bláha, P.; Doležalová, Hana; Duras, R.; Müller, Karel

Zeszyt 4, č. 4 (2007), s. 5-12 ISSN 1896-3145 Institutional research plan: CEZ:AV0Z30860518 Keywords : resistivity * subsidence * geophysics Subject RIV: DC - Siesmology, Volcanology, Earth Structure www.wydawnictwopolitechniki.pl

Subsidence over AML and its causes - A case study

International Nuclear Information System (INIS)

Peng, S.S.; Lin, P.M.; Hsiung, S.M.

1988-01-01

Subsidence over abandoned mined lands can be attributed to several causes. For purposes of compensation and liability and developing remedial measures, it is essential to identify the real causes. The detailed procedures for a subsidence investigation and the keys to identify and determine the causes and severity of the damages are illustrated and discussed through a case study in this paper. A subsidence check list has been developed for investigation purposes. The case discussed in this paper is a mining-related subsidence. The associated subsidence index was 60%. The damage to the dwelling was due to tension. The major damage was developed within two days. A crackmeter was installed on the exterior wall to monitor the house movement. An inclinometer casing and a Sondex casing were installed in a borehole to monitor the ground movement. The results of the geotechnical instrumentation are presented to illustrate the procedures developed for investigating the subsidence cases over the abandoned mine lands

Coal mine subsidence and structures

International Nuclear Information System (INIS)

Gray, R.E.

1988-01-01

Underground coal mining has occurred beneath 32 x 10 9 m 2 (8 million acres) of land in the United States and will eventually extend beneath 162 x 10 9 m 2 (40 million acres). Most of this mining has taken place and will take place in the eastern half of the United States. In areas of abandoned mines where total extraction was not achieved, roof collapse, crushing of coal pillars, or punching of coal pillars into softer mine floor or roof rock is now resulting in sinkhole or trough subsidence tens or even hundreds of years after mining. Difference in geology, in mining, and building construction practice between Europe and the United States preclude direct transfer of European subsidence engineering experience. Building damage cannot be related simply to tensile and compressive strains at the ground surface. Recognition of the subsidence damage role played by ground-structure interaction and by structural details is needed

Subsidence due to Excessive Groundwater Withdrawal in the San Joaquin Valley, California

Science.gov (United States)

Corbett, F.; Harter, T.; Sneed, M.

2011-12-01

subsidence drivers. The model is calibrated to both measured and extrapolated subsidence data. Sensitivity analyses are implemented and several future scenarios evaluated: reduced pumping, 'business as usual' pumping, and increased pumping demand. We show that water level decline, beginning in the 1950s and ending in the early 1970s, is followed closely by subsidence. Also, recent groundwater pumping is shown to drive renewed subsidence. An evaluation of agricultural water use, the main driver of groundwater level decline, shows that deficit irrigation, switching to crops with significantly lower consumptive water use, and active recharge programs are key to addressing long-term groundwater overdraft in light of limited surface water resources.

Review of subsidence and stabilization techniques

International Nuclear Information System (INIS)

Fernando, D.A.

1988-01-01

In Britain the damage caused by underground coal mining operations approximates to about 100 million pounds Sterling per annum, most of the damage resulting from longwall mining operations. Causes of subsidence can be attributed to the following factors: (1) roof failure (2) pillar failure (3) floor movements. Currently, in Britain, the mining industry is undergoing a state of decline for economic reasons. Consequently, the number of old coal sites available for development schemes has increased. Therefore, the problems associated with subsidence can be segregated into two parts. The first being the mitigation of the effects of subsidence on structures on actively mined areas. The second being the stabilization and rehabilitation of ground over and around old mine sites for new development schemes. In the former case the stabilization techniques employed may be local or global, depending on the problems encountered in any particular area. In the latter case, generally, grouting techniques are employed. This paper aims to review the causes of subsidence and the techniques used to minimize its effect on structures. Also, more economic alternative methods of ground stabilization techniques are described and proposed, to be used in this area of ground engineering

Land subsidence caused by a single water extraction well and rapid water infiltration

Directory of Open Access Journals (Sweden)

I. Martinez-Noguez

2015-11-01

Full Text Available Nowadays several parts of the world suffer from land subsidence. This setting of the earth surface occurs due to different factors such as earth quakes, mining activities, and gas, oil and water withdrawal. This research presents a numerical study of the influence of land subsidence caused by a single water extraction well and rapid water infiltration into structural soil discontinuities. The numerical simulation of the infiltration was based on a two-phase flow-model for porous media, and for the deformation a Mohr–Coulomb model was used. A two-layered system with a fault zone is presented. First a single water extraction well is simulated producing a cone-shaped (conical water level depletion, which can cause land subsidence. Land Subsidence can be further increased if a hydrological barrier as a result of a discontinuity, exists. After water extraction a water column is applied on the top boundary for one hours in order to represent a strong storm which produces rapid water infiltration through the discontinuity as well as soil deformation. Both events are analysed and compared in order to characterize deformation of both elements and to get a better understanding of the land subsidence and new fracture formations.

Subsidence and carbon loss in drained tropical peatlands

Directory of Open Access Journals (Sweden)

A. Hooijer

2012-03-01

Full Text Available Conversion of tropical peatlands to agriculture leads to a release of carbon from previously stable, long-term storage, resulting in land subsidence that can be a surrogate measure of CO₂ emissions to the atmosphere. We present an analysis of recent large-scale subsidence monitoring studies in Acacia and oil palm plantations on peatland in SE Asia, and compare the findings with previous studies. Subsidence in the first 5 yr after drainage was found to be 142 cm, of which 75 cm occurred in the first year. After 5 yr, the subsidence rate in both plantation types, at average water table depths of 0.7 m, remained constant at around 5 cm yr⁻¹. The results confirm that primary consolidation contributed substantially to total subsidence only in the first year after drainage, that secondary consolidation was negligible, and that the amount of compaction was also much reduced within 5 yr. Over 5 yr after drainage, 75 % of cumulative subsidence was caused by peat oxidation, and after 18 yr this was 92 %. The average rate of carbon loss over the first 5 yr was 178 t CO_2eq ha⁻¹ yr⁻¹, which reduced to 73 t CO_2eq ha⁻¹ yr⁻¹ over subsequent years, potentially resulting in an average loss of 100 t CO_2eq ha⁻¹ yr⁻¹ over 25 yr. Part of the observed range in subsidence and carbon loss values is explained by differences in water table depth, but vegetation cover and other factors such as addition of fertilizers also influence peat oxidation. A relationship with groundwater table depth shows that subsidence and carbon loss are still considerable even at the highest water levels theoretically possible in plantations. This implies that improved plantation water management will reduce these impacts by 20 % at most, relative to current conditions, and that high rates of carbon loss and land subsidence are

Potential of Holocene deltaic sequences for subsidence due to peat compaction

NARCIS (Netherlands)

Stouthamer, E.; van Asselen, S.

2015-01-01

Land subsidence is a major threat for the livability of deltas worldwide. Mitigation of the negative impacts of subsidence, like increasing flooding risk, requires an assessment of the potential of the deltas’ subsurfaces for subsidence. This enables the prediction of current and future subsidence

Underground coal mine subsidence impacts on surface water

International Nuclear Information System (INIS)

Stump, D.E. Jr.

1992-01-01

This paper reports that subsidence from underground coal mining alters surface water discharge and availability. The magnitude and areal extent of these impacts are dependent on many factors, including the amount of subsidence, topography, geology, climate, surface water - ground water interactions, and fractures in the overburden. There alterations may have positive and/or negative impacts. One of the most significant surface water impacts occurred in July 1957 near West Pittston, Pennsylvania. Subsidence in the Knox Mine under the Coxton Yards of the Lehigh Valley Railroad allowed part of the discharge in the Susquehanna River to flow into the mine and create a crater 200 feet in diameter and 300 feet deep. Fourteen railroad gondola cars fell into the hole which was eventually filled with rock, sand, and gravel. Other surface water impacts from subsidence may include the loss of water to the ground water system, the gaining of water from the ground water system, the creation of flooded subsidence troughs, the increasing of impoundment storage capacity, the relocation of water sources (springs), and the alteration of surface drainage patterns

Detecting and monitoring UCG subsidence with InSAR

Energy Technology Data Exchange (ETDEWEB)

Mellors, R J; Foxall, W; Yang, X

2012-03-23

The use of interferometric synthetic aperture radar (InSAR) to measure surface subsidence caused by Underground Coal Gasification (UCG) is tested. InSAR is a remote sensing technique that uses Synthetic Aperture Radar images to make spatial images of surface deformation and may be deployed from satellite or an airplane. With current commercial satellite data, the technique works best in areas with little vegetation or farming activity. UCG subsidence is generally caused by roof collapse, which adversely affects UCG operations due to gas loss and is therefore important to monitor. Previous studies have demonstrated the usefulness of InSAR in measuring surface subsidence related to coal mining and surface deformation caused by a coal mining roof collapse in Crandall Canyon, Utah is imaged as a proof-of-concept. InSAR data is collected and processed over three known UCG operations including two pilot plants (Majuba, South Africa and Wulanchabu, China) and an operational plant (Angren, Uzbekistan). A clear f eature showing approximately 7 cm of subsidence is observed in the UCG field in Angren. Subsidence is not observed in the other two areas, which produce from deeper coal seams and processed a smaller volume. The results show that in some cases, InSAR is a useful tool to image UCG related subsidence. Data from newer satellites and improved algorithms will improve effectiveness.

An integrated assessment framework for land subsidence in delta cities

Directory of Open Access Journals (Sweden)

T. H. M. Bucx

2015-11-01

Full Text Available In many delta cities land subsidence exceeds absolute sea level rise up to a factor of ten by excessive groundwater extraction related to rapid urbanization and population growth. Without change, parts of Jakarta, Ho Chi Minh City, Bangkok and numerous other delta (and coastal cities will sink below sea level. Increased flooding and also other widespread impacts of land subsidence result already in damage of billions of dollars per year. In order to gain insight in the complex, multi-sectoral aspects of subsidence, to raise awareness and to support decision making on appropriate adaptation strategies and measures, an Integrated Assessment Framework (IAF for subsidence is introduced, illustrated by several (delta case studies. Based on that a list of 10 generic key issues and possible solutions is presented in order to further develop and support a (generic approach how to deal with subsidence in current and future subsidence-prone areas. For exchange of experiences and knowledge development.on subsidence in deltas the Delta Alliance, a knowledge network of deltas worldwide, can be supportive.

Combination of poroelasticity theory and constant strain rate test in modelling land subsidence due to groundwater extraction

Science.gov (United States)

Pham, Tien Hung; Rühaak, Wolfram; Sass, Ingo

2017-04-01

Extensive groundwater extraction leads to a drawdown of the ground water table. Consequently, soil effective stress increases and can cause land subsidence. Analysis of land subsidence generally requires a numerical model based on poroelasticity theory, which was first proposed by Biot (1941). In the review of regional land subsidence accompanying groundwater extraction, Galloway and Burbey (2011) stated that more research and application is needed in coupling of stress-dependent land subsidence process. In geotechnical field, the constant rate of strain tests (CRS) was first introduced in 1969 (Smith and Wahls 1969) and was standardized in 1982 through the designation D4186-82 by American Society for Testing and Materials. From the reading values of CRS tests, the stress-dependent parameters of poroelasticity model can be calculated. So far, there is no research to link poroelasticity theory with CRS tests in modelling land subsidence due to groundwater extraction. One dimensional CRS tests using conventional compression cell and three dimension CRS tests using Rowe cell were performed. The tests were also modelled by using finite element method with mixed elements. Back analysis technique is used to find the suitable values of hydraulic conductivity and bulk modulus that depend on the stress or void ratio. Finally, the obtained results are used in land subsidence models. Biot, M. A. (1941). "General theory of three-dimensional consolidation." Journal of applied physics 12(2): 155-164. Galloway, D. L. and T. J. Burbey (2011). "Review: Regional land subsidence accompanying groundwater extraction." Hydrogeology Journal 19(8): 1459-1486. Smith, R. E. and H. E. Wahls (1969). "Consolidation under constant rates of strain." Journal of Soil Mechanics & Foundations Div.

Formation mechanism of land subsidence in the North China Plain

Science.gov (United States)

Guo, Haipeng; Cheng, Guoming

2014-05-01

Land subsidence is a progressive and gradual geological disaster, whose development is irreversible. Due to rapid development of industrialization and urbanization, land subsidence occurs commonly in the North China Plain, and has become the main environmental factor impacting sustainable economic and social development. This study presents a brief review on the current situation of land subsidence in the North China Plain. Then the hydrologic, hydrogeologic and anthropogenic conditions favorable for the formation of land subsidence are analyzed, indicating that the formation of land subsidence is mainly determined by local geological condition and enabling conditions, e.g. long-term excessive exploitation of groundwater and engineering construction. A correlation analysis was conducted in both the North China Plain and Cangzhou region, a typical area where severe land subsidence occurs, of the quantitative relationship between deep groundwater yield and the land subsidence. The analysis results indicate that the land subsidence volume accounts for 40% to 44% of deep water yield in the North China Plain, indirectly showing the proportion of released water from compressibility of the aquifer and the aquitard in deep groundwater yield. In Cangzhou region, this proportion was calculated as 58%, far greater than that of the North China Plain. This is induced by the local lithologic structure and recharge condition of deep groundwater in Cangzhou region. The analysis of soil samples in Cangzhou region shows that strong relations exist among different physical parameters, and good change laws of compression with depth and pressure are found for soil samples. The hydraulic conductivities of clay are six orders of magnitude greater than those of the aquifer, implying the strong hypothesis of land subsidence. This analysis provides data and scientific basis for further study on formation mechanism of land subsidence in Cangzhou region and objective evaluation of its

Land subsidence and caprock dolines caused by subsurface gypsum dissolution and the effect of subsidence on the fluvial system in the Upper Tigris Basin (between Bismil Batman, Turkey)

Science.gov (United States)

Doğan, Uğur

2005-11-01

Karstification-based land subsidence was found in the Upper Tigris Basin with dimensions not seen anywhere else in Turkey. The area of land subsidence, where there are secondary and tertiary subsidence developments, reaches 140 km 2. Subsidence depth ranges between 40 and 70 m. The subsidence was formed as a result of subsurface gypsum dissolution in Lower Miocene formation. Although there are limestones together with gypsum and Eocene limestone below them in the area, a subsidence with such a large area is indicative of karstification in the gypsum. The stratigraphical cross-sections taken from the wells and the water analyses also verify this fact. The Lower Miocene gypsum, which shows confined aquifer features, was completely dissolved by the aggressive waters injected from the top and discharged through by Zellek Fault. This resulted in the development of subsidence and formation of caprock dolines on loosely textured Upper Miocene-Pliocene cover formations. The Tigris River runs through the subsidence area between Batman and Bismil. There are four terrace levels as T1 (40 m), T2 (30 m), T3 (10 m) and T4 (4-5 m) in the Tigris River valley. It was also found that there were some movements of the levels of the terraces in the valley by subsidence. The subsidence developed gradually throughout the Quaternary; however no terrace was formed purely because of subsidence.

Subsidence from an artificial permafrost warming experiment.

Science.gov (United States)

Gelvin, A.; Wagner, A. M.; Lindsey, N.; Dou, S.; Martin, E. R.; Ekblaw, I.; Ulrich, C.; James, S. R.; Freifeld, B. M.; Daley, T. M.; Saari, S.; Ajo Franklin, J. B.

2017-12-01

Using fiber optic sensing technologies (seismic, strain, and temperature) we installed a geophysical detection system to predict thaw subsidence in Fairbanks, Alaska, United States. Approximately 5 km of fiber optic was buried in shallow trenches (20 cm depth), in an area with discontinuous permafrost, where the top of the permafrost is approximately 4 - 4.5m below the surface. The thaw subsidence was enforced by 122 60-Watt vertical heaters installed over a 140 m2 area where seismic, strain, and temperature were continuously monitored throughout the length of the fiber. Several vertical thermistor strings were also recording ground temperatures to a depth of 10 m in parallel to the fiber optic to verify the measurements collected from the fiber optic cable. GPS, Electronic Distance Measurement (EDM) Traditional and LiDAR (Light and Detection and Ranging) scanning were used to investigate the surface subsidence. The heaters were operating for approximately a three month period starting in August, 2016. During the heating process the soil temperatures at the heater element increased from 3.5 to 45 °C at a depth of 3 - 4 m. It took approximately 7 months for the temperature at the heater elements to recover to their initial temperature. The depth to the permafrost table was deepened by about 1 m during the heating process. By the end of the active heating, the surface had subsided approximately 8 cm in the heating section where permafrost was closest to the surface. This was conclusively confirmed with GPS, EDM, and LiDAR. An additional LiDAR survey was performed about seven months after the heaters were turned off (in May 2017). A total subsidence of approximately 20 cm was measured by the end of the passive heating process. This project successfully demonstrates that this is a viable approach for simulating both deep permafrost thaw and the resulting surface subsidence.

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...

Determination of intensity functions for predicting subsidence from coal mining, potash mining, and groundwater withdrawal using the influence function technique

Energy Technology Data Exchange (ETDEWEB)

Triplett, T; Yurchak, D [Twin Cities Research Center, Bureau of Mines, US Dept. of the Interior, Minneapolis, MN (United States)

1997-12-31

This paper presents research, conducted by the Bureau of Mines, on modifying the influence function method to predict subsidence. According to theory, this technique must incorporate an intensity function to represent the relative significance of the causes of subsidence. This paper shows that the inclusion of a reasonable intensity function increases the accuracy of the technique, then presents the required functions for case studies of longwall coal mining subsidence in Illinois, USA, potash mining subsidence in new Mexico, USA, and subsidence produced by ground water withdrawal in California, USA. Finally, the paper discusses a method to predict the resultant strain from a simply measured site constant and ground curvatures calculated by the technique. (orig.)

Determination of intensity functions for predicting subsidence from coal mining, potash mining, and groundwater withdrawal using the influence function technique

Energy Technology Data Exchange (ETDEWEB)

Triplett, T.; Yurchak, D. [Twin Cities Research Center, Bureau of Mines, US Dept. of the Interior, Minneapolis, MN (United States)

1996-12-31

This paper presents research, conducted by the Bureau of Mines, on modifying the influence function method to predict subsidence. According to theory, this technique must incorporate an intensity function to represent the relative significance of the causes of subsidence. This paper shows that the inclusion of a reasonable intensity function increases the accuracy of the technique, then presents the required functions for case studies of longwall coal mining subsidence in Illinois, USA, potash mining subsidence in new Mexico, USA, and subsidence produced by ground water withdrawal in California, USA. Finally, the paper discusses a method to predict the resultant strain from a simply measured site constant and ground curvatures calculated by the technique. (orig.)

Land subsidence in Yunlin, Taiwan, due to Agricultural and Domestic Water Use

Science.gov (United States)

Hsu, K.; Lin, P.; Lin, Z.

2013-12-01

Subsidence in a layered aquifer is caused by groundwater excess extraction and results in complicated problems in Taiwan. Commonly, responsibility to subsidence for agricultural and domestic water users is difficulty to identify due to the lack of quantitative evidences. An integrated model was proposed to analyze subsidence problem. The flow field utilizes analytical solution for pumping in a layered system from Neuman and Witherspoon (1969) to calculate the head drawdown variation. The subsidence estimation applies Terzaghi (1943) one-dimensional consolidation theory to calculate the deformation in each layer. The proposed model was applied to estimate land subsidence and drawdown variation at the Yuanchang Township of Yunlin County in Taiwan. Groundwater data for dry-season periods were used for calibration and validation. Seasonal effect in groundwater variation was first filtered out. Dry-season pumping effect on land subsidence was analyzed. The results show that multi-layer pumping contributes more in subsidence than single-layer pumping on the response of drawdown and land subsidence in aquifer 2 with a contribution of 97% total change at Yuanchang station. Pumping in aquifer 2 contributes more significant than pumping in aquifer 3 to cause change in drawdown and land subsidence in aquifer 2 with a contribution of 70% total change at Yuanchang station. Larger area of subsidence in Yuanchang Township was attributed pumping at aquifer 2 while pumping at aquifer 3 results in significant subsidence near the well field. The single-layer user contributes most area of subsidence but the multi-layer user generates more serious subsidence.

Subsidence prediction in Estonia's oil shale mines

International Nuclear Information System (INIS)

Pastarus, J.R.; Toomik, A.

2000-01-01

This paper analysis the stability of the mining blocks in Estonian oil shale mines, where the room-and-pillar mining system is used. The pillars are arranged in a singular grid. The oil shale bed is embedded at the depth of 40-75 m. The processes in overburden rocks and pillars have caused the subsidence of the ground surface. The conditional thickness and sliding rectangle methods performed calculations. The results are presented by conditional thickness contours. Error does not exceed 4%. Model allows determining the parameters of spontaneous collapse of the pillars and surface subsidence. The surface subsidence parameters will be determined by conventional calculation scheme. Proposed method suits for stability analysis, failure prognosis and monitoring. 8 refs

The interaction between land subsidence and urban development in China

Directory of Open Access Journals (Sweden)

Y. Yang

2015-11-01

Full Text Available The Yangtze River Delta and North China Plain are experiencing serious land subsidence development and are also the areas that have undergone the fastest urbanization. Rapid urban development inevitably requires more water resources. However, China is a country with small per capita water resources, nonuniform distribution of water resources, and over-exploitation of groundwater – all of which are critical factors contributing to the potential for a land subsidence disaster. In addition, land subsidence has brought about elevation loss, damaged buildings, decreased safety of rail transit projects, lowered land value, and other huge economic losses and potential safety hazards in China. In this paper, Beijing, a typical northern Chinese city deficient in water, is taken as an example to explore (a the problems of urban development, utilization of water resources, and land subsidence development; (b the harm and influence of land subsidence hazards on urban construction; and (c the relationship between urban development and land subsidence. Based on the results, the author has predicted the trend of urban development and land subsidence in Beijing and puts forward her viewpoints and suggestions.

A study on the mechanism and prediction of mine subsidence

Energy Technology Data Exchange (ETDEWEB)

Kim, Byung-Chan; Moon, Hyun-Koo [Hanyang University, Seoul(Korea)

2001-06-30

The ground subsidence problem due to the increasing number of abandoned coal mines becomes serious. Recently, the sinkhole type subsidence occurred in many abandoned mines has raised an urgent stability question on the nearby railroads, bridges and buildings. But the study on the mechanism of discontinuous subsidence has not attracted much attention in the past. This study is mainly concerned with the mechanism and prediction of mine subsidence. Analyzed and presented in this study are the maximum possible height of roof caving for various shapes of caved zone using bulking factor approach, the critical depth of protective coal seam using the limit equilibrium method, and the factor of safety of stops using the limit equilibrium method with the friction angle and cohesion of rock. As prediction tools the influence function method and the probabilistic method are presented. An empirical equation is obtained from the subsidence data in Chulam and Chungsung areas and applied to Manhang coal mine. The probability of subsidence in Manhang area turned out to be high according to the subsidence frequency of 9.66. (author). 12 refs., 7 tabs., 21 figs.

Protection of pipelines affected by surface subsidence

International Nuclear Information System (INIS)

Luo, Y.; Peng, S.S.; Chen, H.J.

1998-01-01

Surface subsidence resulting from underground coal mining can cause problems for buried pipelines. A technique for assessing the level of stress on a subsidence-affected pipeline is introduced. The main contributors to the stress are identified, and mitigation techniques for reducing the stress are proposed. The proposed mitigation techniques were then successfully tested. 13 refs., 8 figs., 2 tabs

Problem definition study of subsidence caused by geopressured geothermal resource development

Energy Technology Data Exchange (ETDEWEB)

1980-12-01

The environmental and socio-economic settings of four environmentally representative Gulf Coast geopressured geothermal fairways were inventoried. Subsidence predictions were prepared using feasible development scenarios for the four representative subsidence sites. Based on the results of the subsidence estimates, an assessment of the associated potential environmental and socioeconomic impacts was prepared. An inventory of mitigation measures was also compiled. Results of the subsidence estimates and impact assessments are presented, as well as conclusions as to what are the major uncertainties, problems, and issues concerning the future study of geopressured geothermal subsidence.

Evaluation of mining subsidence using GPS data

Czech Academy of Sciences Publication Activity Database

Doležalová, Hana; Kajzar, Vlastimil; Souček, Kamil; Staš, Lubomír

2009-01-01

Roč. 6, č. 3 (2009), s. 359-367 ISSN 1214-9705. [Czech - Polish Workshop on recent geodynamics of the Sudeten and adjacent areas /9./. Náchod, 12.11.2009-15.11.2009] R&D Projects: GA ČR GA105/07/1586 Institutional research plan: CEZ:AV0Z30860518 Keywords : undermining * subsidence depression * tectonic faults Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 0.275, year: 2009 http://apps.isiknowledge.com/full_record.do?product=UA&search_mode

Physical assessment of coastal vulnerability under enhanced land subsidence in Semarang, Indonesia, using multi-sensor satellite data

Science.gov (United States)

Husnayaen; Rimba, A. Besse; Osawa, Takahiro; Parwata, I. Nyoman Sudi; As-syakur, Abd. Rahman; Kasim, Faizal; Astarini, Ida Ayu

2018-04-01

Research has been conducted in Semarang, Indonesia, to assess coastal vulnerability under enhanced land subsidence using multi-sensor satellite data, including the Advanced Land Observing Satellite (ALOS) Phased Array type L-band SAR (PALSAR), Landsat TM, IKONOS, and TOPEX/Poseidon. A coastal vulnerability index (CVI) was constructed to estimate the level of vulnerability of a coastline approximately 48.68 km in length using seven physical variables, namely, land subsidence, relative sea level change, coastal geomorphology, coastal slope, shoreline change, mean tidal range, and significant wave height. A comparison was also performed between a CVI calculated using seven parameters and a CVI using six parameters, the latter of which excludes the land subsidence parameter, to determine the effects of land subsidence during the coastal vulnerability assessment. This study showed that the accuracy of coastal vulnerability was increased 40% by adding the land subsidence factor (i.e., CVI 6 parameters = 53%, CVI 7 parameters = 93%). Moreover, Kappa coefficient indicated very good agreement (0.90) for CVI 7 parameters and fair agreement (0.3) for CVI 6 parameters. The results indicate that the area of very high vulnerability increased by 7% when land subsidence was added. Hence, using the CVI calculation including land subsidence parameters, the very high vulnerability area is determined to be 20% of the total coastline or 9.7 km of the total 48.7 km of coastline. This study proved that land subsidence has significant influence on coastal vulnerability in Semarang.

La subsidence dans le Viking Graben (mer du Nord septentrionale Subsidence in the Viking Graben (Northern Part of the North Sea

Directory of Open Access Journals (Sweden)

Vially R.

2006-11-01

Full Text Available L'utilisation des modèles numériques de calcul de la subsidence nécessite une bonne connaissance géologique de la zone étudiée. Seule une étude détaillée de stratigraphie sismique le long de profils régionaux passant par des forages permet de contraindre les différents paramètres servant au calcul de la subsidence. L'étude de la subsidence du Viking Graben a mis en évidence trois épisodes : - phase de distension permo-triasique (saalienne ? dont l'axe de subsidence est décalé vers l'est par rapport à l'axe actuel du Viking Graben; - phase de distension jurassique supérieur (cimmérienne qui crée les structures majeures de cette zone; - phase paléocène correspondant au contrecoup de l'ouverture plus à l'ouest de l'Atlantique Nord. Cette phase est surtout sensible à l'ouest de la zone étudiée. Les cartes de subsidence pour les différentes époques font apparaître l'influence du bati calédonien. Deux directions principales apparaissent, une NE-SW correspondant aux directions structurales visibles à terre en Ecosse et une NW-SE discrète qui sépare le Southern Viking Graben du Northern Viking Graben. Cette dernière direction pourrait se calquer sur la suture (au Silurien d'un diverticule de l'océan lapétus, la Tornquist Sea. The use of numerical models for computing subsidence requires a good geological understanding of the zone being examined. Detailed seismic stratigraphy along regional profiles going via boreholes is the only way to determine the different parameters required for computing subsidence. An investigation of the subsidence of the Viking Graben in the North Sea has revealed three episodes:(a The Permo-Triassic (Saalian ? distension phase during which the axis of subsidence lay to the east of the present axis of the Viking Graben. (b The later Jurassic (Kimmerian distension phase which created the major structures in this zone. (c The Paleocene phase corresponding to the backlash of the westward

Observation of heights on the margin of subsidence depression

Czech Academy of Sciences Publication Activity Database

Bláha, P.; Doležalová, Hana; Müller, Karel; Skopal, R.

2006-01-01

Roč. 6, č. 2 (2006), s. 9-15 ISSN 1213-1962. [Nové poznatky a měření v seismologii, inženýrské geofyzice a geotechnice/15./. Ostrava, 11.04.2006-13.04.2006] Institutional research plan: CEZ:AV0Z30860518 Keywords : subsidence depression * levelling * fluctuation Subject RIV: DC - Siesmology, Volcanology, Earth Structure

U.S. Geological Survey Subsidence Interest Group conference, Edwards Air Force Base, Antelope Valley, California, November 18-19, 1992; abstracts and summary

Science.gov (United States)

Prince, Keith R.; Galloway, Devin L.; Leake, Stanley A.

1995-01-01

with this unprecedented increase in pumpage, substantial amounts of land subsidence were observed in several areas of the United States, most notably in Arizona, California, and Texas. Beginning in 1955, under the direction of Joseph Poland, the Geological Survey began the "Mechanics of Aquifers Project," which focused largely on the processes that resulted in land subsidence due to the withdrawal of ground water. This research team gained international renown as they advanced the scientific understanding of aquifer mechanics and land-subsidence theory. The results of field studies by members of this research group not only verified the validity of the application of Terzaghi's consolidation theory to compressible aquifers, but they also provided definitions, methods of quantification, and confirmation of the interrelation among hydraulic head declines, aquifer-system compaction, and land subsidence. In addition to conducting pioneering research, this group also formed a "center of expertise," providing a focal point within the Geological Survey for the dissemination of technology and scientific understanding in aquifer mechanics. However, when the "Mechanics of Aquifers Project" was phased out in 1984, the focal point for technology transfer no longer existed. Interest among various state and local agencies in land subsidence has persisted, and the Geological Survey has continued to participate in a broad spectrum of cooperative and Federally funded projects in aquifer mechanics and land subsidence. These projects are designed to identify and monitor areas with the potential for land subsidence, to conduct basic research in the processes that control land subsidence and the development of earth fissures, as well as to develop new quantitative tools to predict aquifer-system deformation. In 1989 an ad hoc "Aquifer Mechanics and Subsidence Interest Group" (referred to herein as the "Subsidence Interest Group") was formed

November 2016 West Hackberry Subsidence Report

Energy Technology Data Exchange (ETDEWEB)

Moriarty, Dylan Michael [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Lord, Anna C. Snider [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2017-02-01

Subsidence monitoring is a critical component to understanding the cavern integrity of salt storage caverns. This report looks at historical and recent data from two of the three West Hackberry dome cavern operators. DOE SPR and LA Storage are coordinating subsidence surveys to create a comprehensive understanding of ground movement above the dome. Data from annual level and rod surveys, GPS, and tiltmeter data show the sites are experiencing typical ground movement. The highest subsidence rate is seen in the middle of the DOE SPR site at just under one inch per year with less ground movement around the edge of the site. A GPS and tiltmeter instrument in the northeast areas of the DOE SPR site has not seen any trend change since the devices were installed in 2013. Comparison between recent ground movement data and historical trends suggest that there is no reason to believe that any DOE SPR or LA Storage caverns have been structurally compromised.

How large-scale subsidence affects stratocumulus transitions

Directory of Open Access Journals (Sweden)

J. J. van der Dussen

2016-01-01

Full Text Available Some climate modeling results suggest that the Hadley circulation might weaken in a future climate, causing a subsequent reduction in the large-scale subsidence velocity in the subtropics. In this study we analyze the cloud liquid water path (LWP budget from large-eddy simulation (LES results of three idealized stratocumulus transition cases, each with a different subsidence rate. As shown in previous studies a reduced subsidence is found to lead to a deeper stratocumulus-topped boundary layer, an enhanced cloud-top entrainment rate and a delay in the transition of stratocumulus clouds into shallow cumulus clouds during its equatorwards advection by the prevailing trade winds. The effect of a reduction of the subsidence rate can be summarized as follows. The initial deepening of the stratocumulus layer is partly counteracted by an enhanced absorption of solar radiation. After some hours the deepening of the boundary layer is accelerated by an enhancement of the entrainment rate. Because this is accompanied by a change in the cloud-base turbulent fluxes of moisture and heat, the net change in the LWP due to changes in the turbulent flux profiles is negligibly small.

Land Subsidence Monitoring by InSAR Time Series Technique Derived From ALOS-2 PALSAR-2 over Surabaya City, Indonesia

Science.gov (United States)

Aditiya, A.; Takeuchi, W.; Aoki, Y.

2017-12-01

Surabaya is the second largest city in Indonesia and the capital of East Java Province with rapid population and industrialization. The impact of urbanization in the big city can suffer potential disasters either nature or anthropogenic such as land subsidence and flood. The pattern of land subsidence need to be mapped for the purposes of planning and structuring the city as well as taking appropriate policy in anticipating and mitigating the impact. This research has used interferometric Synthetic Aperture Radar (InSAR) Small Baseline Subset (SBAS) technique and applied time series analysis to investigate land subsidence occured. The technique includes the process of focusing the SAR data, incorporating the precise orbit, generating interferogram and phase unwrapping using SNAPHU algorithms. The results showed land subsidence has been detected during 2014-2017 over Surabaya city area using ALOS-2/PALSAR-2 images data. These results reveal the subsidence has observed in several area in Surabaya in particular northern part reach up to ∼2 cm/year. The fastest subsidence occurs in highly populated areas suffer vulnerable to flooding and sea level rise impact. In urban areas we found a correlation between land subsidence with residential or industrial land use. It concludes that land subsidence is mainly caused by ground water consumption for industrial and residential use respectively.

Quantitative analysis of the tectonic subsidence in the Potiguar Basin (NE Brazil)

Science.gov (United States)

Lopes, Juliana A. G.; de Castro, David L.; Bertotti, Giovanni

2018-06-01

The Potiguar Basin, located in the Brazilian Equatorial Margin, evolved from a complex rifting process implemented during the Atlantic Ocean opening in the Jurassic/Cretaceous. Different driving mechanisms were responsible for the onset of an aborted onshore rift and an offshore rift that initiated crustal rupture and the formation of a continental transform margin. Therefore, we applied the backstripping method to quantify the tectonic subsidence during the rift and post-rift phases of Potiguar Basin formation and to analyze the spatial variation of subsidence during the two successive and distinct tectonic events responsible for the basin evolution. The parameters required to apply this methodology were extracted from 2D seismic lines and exploratory well data. The tectonic subsidence curves present periods with moderate subsidence rates (up to 300 m/My), which correspond to the evolution of the onshore Potiguar Rift (∼141 to 128 Ma). From 128-118 Ma, the tectonic subsidence curves show no subsidence in the onshore Potiguar Basin, whereas subsidence occurred at high rates (over 300 m/My) in the offshore rift. The post-rift phase began ca. 118 Ma (Aptian), when the tectonic subsidence drastically slowed to less than 35 m/My, probably related to thermal relaxation. The tectonic subsidence rates in the various sectors of the Potiguar Rift, during the different rift phases, indicate that more intense faulting occurred in the southern portion of the onshore rift, along the main border faults, and in the southeastern portion of the offshore rift. During the post-rift phase, the tectonic subsidence rates increased from the onshore portion towards the offshore portion until the continental slope. The highest rates of post-rift subsidence (up to 35 m/My) are concentrated in the central region of the offshore portion and may be related to lithospheric processes related to the continental crust rupture and oceanic seafloor spreading. The variation in subsidence rates and

Application of an adaptive neuro-fuzzy inference system to ground subsidence hazard mapping

Science.gov (United States)

Park, Inhye; Choi, Jaewon; Jin Lee, Moung; Lee, Saro

2012-11-01

We constructed hazard maps of ground subsidence around abandoned underground coal mines (AUCMs) in Samcheok City, Korea, using an adaptive neuro-fuzzy inference system (ANFIS) and a geographical information system (GIS). To evaluate the factors related to ground subsidence, a spatial database was constructed from topographic, geologic, mine tunnel, land use, and ground subsidence maps. An attribute database was also constructed from field investigations and reports on existing ground subsidence areas at the study site. Five major factors causing ground subsidence were extracted: (1) depth of drift; (2) distance from drift; (3) slope gradient; (4) geology; and (5) land use. The adaptive ANFIS model with different types of membership functions (MFs) was then applied for ground subsidence hazard mapping in the study area. Two ground subsidence hazard maps were prepared using the different MFs. Finally, the resulting ground subsidence hazard maps were validated using the ground subsidence test data which were not used for training the ANFIS. The validation results showed 95.12% accuracy using the generalized bell-shaped MF model and 94.94% accuracy using the Sigmoidal2 MF model. These accuracy results show that an ANFIS can be an effective tool in ground subsidence hazard mapping. Analysis of ground subsidence with the ANFIS model suggests that quantitative analysis of ground subsidence near AUCMs is possible.

Update on subsidence at the Wairakei-Tauhara geothermal system, New Zealand

International Nuclear Information System (INIS)

Allis, Rick; Bromley, Chris; Currie, Steve

2009-01-01

The total subsidence at the Wairakei field as a result of 50 years of geothermal fluid extraction is 15 ± 0.5 m. Subsidence rates in the center of the subsidence bowl have decreased from over 450 mm/year during the 1970s to 80-90 mm/year during 2000-2007. The location of the bowl, adjacent to the original liquid outflow zone of the field, has not changed significantly. Subsidence at the Tauhara field due to Wairakei production was not as well documented in the early years but appeared later and has been less intense than at Wairakei. Total subsidence of 2.6 ± 0.5 m has also occurred close to the original liquid outflow zone of this field, and maximum subsidence rates in this area today are in the 80-100 mm/year range. In the western part of the Wairakei field, near the area of hot upflow, subsidence rates have approximately doubled during the last 20 years to 30-50 mm/year. This increase appears to be have been caused by declining pressure in the underlying steam zone in this area, which is tapped by some production wells. At Tauhara field, two areas of subsidence have developed since the 1990s with rates of 50-65 mm/year. Although less well-determined, this subsidence may also be caused by declining pressure in shallow steam zones. The cause of the main subsidence bowls in the Wairakei-Tauhara geothermal system is locally high-compressibility rocks within the Huka Falls Formation (HFF), which are predominantly lake sediments and an intervening layer of pumice breccia. At Wairakei, casing deformation suggests the greatest compaction is at 150-200 m depth. The cause of the large compressibility is inferred to be higher clay content in the HFF due to intense hydrothermal alteration close to the natural fluid discharge areas. Future subsidence is predicted to add an additional 2-4 m to the Wairakei bowl, and 1-2 m elsewhere, but these estimates depend on the assumed production-injection scenarios. (author)

Subsidence in the holocene delta of The Netherlands

NARCIS (Netherlands)

Vonhögen, L.M.; Doornenbal, P.J.; Lange, G. de; Fokker, P.A.; Gunnink, J.L.

2010-01-01

The low-lying part of The Netherlands is very vulnerable in terms of surface subsidence due to peat oxidation and peat/clay compaction. To gain knowledge about this kind of subsidence and the factors driving it, a study was performed in which as many surface elevation data were collected as possible

Groundwater-pumping optimization for land-subsidence control in Beijing plain, China

Science.gov (United States)

Qin, Huanhuan; Andrews, Charles B.; Tian, Fang; Cao, Guoliang; Luo, Yong; Liu, Jiurong; Zheng, Chunmiao

2018-01-01

Beijing, in the North China plain, is one of the few megacities that uses groundwater as its main source of water supply. Groundwater accounts for about two-thirds of the city's water supply, and during the past 50 years the storage depletion from the unconsolidated aquifers underlying the city has been >10.4 billion m3. By 2010, groundwater pumping in the city had resulted in a cumulative subsidence of greater than 100 mm in an area of about 3,900 km2, with a maximum cumulative subsidence of >1,200 mm. This subsidence has caused significant social and economic losses in Beijing, including significant damage to underground utilities. This study was undertaken to evaluate various future pumping scenarios to assist in selecting an optimal pumping scenario to minimize overall subsidence, meet the requirements of the Beijing Land Subsidence Prevention Plan (BLSPP 2013-2020), and be consistent with continued sustainable economic development. A numerical groundwater and land-subsidence model was developed for the aquifer system of the Beijing plain to evaluate land subsidence rates under the possible future pumping scenarios. The optimal pumping scenario consistent with the evaluation constraints is a reduction in groundwater pumping from three major pumping centers by 100, 50 and 20%, respectively, while maintaining an annual pumping rate of 1.9 billion m3. This scenario's land-subsidence rates satisfy the BLSPP 2013-2020 and the pumping scenario is consistent with continued economic development. It is recommended that this pumping scenario be adopted for future land-subsidence management in Beijing.

Groundwater-pumping optimization for land-subsidence control in Beijing plain, China

Science.gov (United States)

Qin, Huanhuan; Andrews, Charles B.; Tian, Fang; Cao, Guoliang; Luo, Yong; Liu, Jiurong; Zheng, Chunmiao

2018-06-01

Beijing, in the North China plain, is one of the few megacities that uses groundwater as its main source of water supply. Groundwater accounts for about two-thirds of the city's water supply, and during the past 50 years the storage depletion from the unconsolidated aquifers underlying the city has been >10.4 billion m3. By 2010, groundwater pumping in the city had resulted in a cumulative subsidence of greater than 100 mm in an area of about 3,900 km2, with a maximum cumulative subsidence of >1,200 mm. This subsidence has caused significant social and economic losses in Beijing, including significant damage to underground utilities. This study was undertaken to evaluate various future pumping scenarios to assist in selecting an optimal pumping scenario to minimize overall subsidence, meet the requirements of the Beijing Land Subsidence Prevention Plan (BLSPP 2013-2020), and be consistent with continued sustainable economic development. A numerical groundwater and land-subsidence model was developed for the aquifer system of the Beijing plain to evaluate land subsidence rates under the possible future pumping scenarios. The optimal pumping scenario consistent with the evaluation constraints is a reduction in groundwater pumping from three major pumping centers by 100, 50 and 20%, respectively, while maintaining an annual pumping rate of 1.9 billion m3. This scenario's land-subsidence rates satisfy the BLSPP 2013-2020 and the pumping scenario is consistent with continued economic development. It is recommended that this pumping scenario be adopted for future land-subsidence management in Beijing.

The Identification of Land Subsidance by Levelling Measurement and GPR Data at Tanjung Emas Harbour, Semarang

Directory of Open Access Journals (Sweden)

Purnomo Raharjo

2017-10-01

Full Text Available Recently, the main problem in Semarang City is flood. This area has low relief that consists of coastal alluvial deposits, swamp and marine sediments. The coastline is characterized by muddy, sandy, and rocky coasts, and mangrove coast. Ground Penetrating Radar (GPR records, show that subsurface geological condition of northern part of Semarang is coastal alluvial deposit and in the south is volcanic rocks. The aims of this this research is to determine land subsidence by levelling measurement in 2005 in Tanjung Emas Harbour area built on 1995. During ten years, there are various land subsidance in this area: in Coaster Street (21 – 41 cm, container wharf (62 – 94 cm, north breakwater (64 – 79 cm, west breakwater (74 – 140 cm, east groin (76 – 89 cm, and stacking area ( 77 – 109 cm. According to this research, it is concluded that one reason causes of flooding in this area is land subsidence.

Subsidence Contours for South Louisiana; UTM 15N NAD83; LRA (2005); [subsidence_contours

Data.gov (United States)

Louisiana Geographic Information Center — The GIS data shapefile represents average subsidence contour intervals (0.02 cm/year over 10,000 years) for Coastal LA derived from the following: Kulp, M.A., 2000,...

Flooding hazards from sea extremes and subsidence

DEFF Research Database (Denmark)

Sørensen, Carlo; Vognsen, Karsten; Broge, Niels

2015-01-01

of tide gauge records, statistics that allow also for projections of SLR, meteorological variability, and extremes with a very low probability of occurrence are provided. Land movement is researched with a focus on short term surface height variability in the groundwater-ocean interface that, together...... with longer term processes, may cause substantial subsidence and impact future water management and adaptation strategies in flood prone coastal areas. Field studies’ results from repeated precise levelling, GPS setups, and ocean and groundwater level monitoring in Thyborøn and Aarhus are integrated...

Natural versus anthropogenic subsidence of Venice.

Science.gov (United States)

Tosi, Luigi; Teatini, Pietro; Strozzi, Tazio

2013-09-26

We detected land displacements of Venice by Persistent Scatterer Interferometry using ERS and ENVISAT C-band and TerraSAR-X and COSMO-SkyMed X-band acquisitions over the periods 1992-2010 and 2008-2011, respectively. By reason of the larger observation period, the C-band sensors was used to quantify the long-term movements, i.e. the subsidence component primarily ascribed to natural processes. The high resolution X-band satellites reveal a high effectiveness to monitor short-time movements as those induced by human activities. Interpolation of the two datasets and removal of the C-band from the X-band map allows discriminating between the natural and anthropogenic components of the subsidence. A certain variability characterizes the natural subsidence (0.9 ± 0.7 mm/yr), mainly because of the heterogeneous nature and age of the lagoon subsoil. The 2008 displacements show that man interventions are responsible for movements ranging from -10 to 2 mm/yr. These displacements are generally local and distributed along the margins of the city islands.

Subsidence in tropical peatlands: Estimating CO2 fluxes from peatlands in Southeast Asia

Science.gov (United States)

Hoyt, A.; Harvey, C. F.; Seppalainen, S. S.; Chaussard, E.

2017-12-01

Tropical peatlands of Southeast Asia are an important global carbon stock. However, they are being rapidly deforested and drained. Peatland drainage facilitates peat decomposition, releases sequestered peat carbon to the atmosphere as CO2, and leads to subsidence of the peat surface. As a result, subsidence measurements can be used to monitor peatland carbon loss over time. Until now, subsidence measurements have been primarily limited to ground-based point measurements using subsidence poles. Here we demonstrate a powerful method to measure peatland subsidence rates across much larger areas than ever before. Using remotely sensed InSAR data, we map subsidence rates across thousands of square kilometers in Southeast Asia and validate our results against ground-based subsidence measurements. The method allows us to monitor subsidence in remote locations, providing unprecedented spatial information, and the first comprehensive survey of land uses such as degraded peatlands, burnt and open areas, shrub lands, and smallholder farmlands. Strong spatial patterns emerged, with the highest subsidence rates occurring at the centers of peat domes, where the peat is thickest and drainage depths are likely to be largest. Peatland subsidence rates were also strongly dependent on current and historical land use, with typical subsidence rates ranging from 2-4 cm/yr. Finally, we scaled up our results to calculate total annual emissions from peat decomposition in degraded peatlands.

Investigation of a subsidence event near Flushing, Ohio

International Nuclear Information System (INIS)

Ledney, C.M.; Hawk, J.L.

1994-01-01

An investigation was undertaken to determine the cause and extent of events which caused problems to a number of residences along State Route 149 near Flushing, Belmont County, Ohio. The events began in 1988 and continued through 1991 and affected nine homes. The type of problems occurring, as well as surface effects, compared to available mine maps of the area, indicated the problems were caused by subsidence from coal mining. The mining occurred in the Pittsburgh seam at a depth of between 180 and 220 feet. The mining beneath the site took place between 1975 and 1977 and was of the room and pillar type. A subsurface investigation was performed, along with ''down the hole'' video camera inspections to provide necessary subsurface information for analysis of the subsidence event. Factors of safety were calculated for pillars throughout the mine. Based on this analysis, it was determined that pillar failure caused the subsidence event. Once a determination was made as to the likely cause of the subsidence, the data was re-examined to determine the possible location of pillar failure, as well as the type and extent of subsidence. This analysis involved the use of RQD versus depth plots and the compilation of isopach maps of the mine overburden and the Sewickley Sandstone. The trend of the two maps suggested that a relationship existed between the sandstone thickness, the overburden and the surface expression of the subsidence. In order to determine this relationship, the two maps were combined into a second order map showing the mine overburden--Sewickley Sandstone thickness ratios. The combination was accomplished by computer matrix operations using the grid values of the two previous maps that were generated by kriging. It was concluded that the ratio of the Sewickley Sandstone thickness to the mine overburden had a tremendous effect on the amount of damage that occurred to specific residences

Land subsidence and hydrodynamic compaction of sedimentary basins

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H. Kooi

1998-01-01

Full Text Available A one-dimensional model is used to investigate the relationship between land subsidence and compaction of basin sediments in response to sediment loading. Analysis of the model equations and numerical experiments demonstrate quasi-linear systems behaviour and show that rates of land subsidence due to compaction: (i can attain a significant fraction (>40% of the long-term sedimentation rate; (ii are hydrodynamically delayed with respect to sediment loading. The delay is controlled by a compaction response time τc that can reach values of 10-5-107 yr for thick shale sequences. Both the behaviour of single sediment layers and multiple-layer systems are analysed. Subsequently the model is applied to the coastal area of the Netherlands to illustrate that lateral variability in compaction-derived land subsidence in sedimentary basins largely reflects the spatial variability in both sediment loading and compaction response time. Typical rates of compaction-derived subsidence predicted by the model are of the order of 0.1 mm/yr but may reach values in excess of 1 mm/yr under favourable conditions.

Influence the condition land subsidence and groundwater impact of Jakarta coastal area

Science.gov (United States)

Rahman, S.; Sumotarto, U.; Pramudito, H.

2018-01-01

Jakarta has been experiencing land subsidence for ten years due toerecting weight building and intensive extraction of groundwater for society drink water through ground water wells. Many groundwater extraction for drinkingwater has caused intensive scouring of land rock and further triggering land subsidence developed widely in coastal area of Jakarta. Measurement of the land subsidence has been performed by various experts and institutes. Between 1974 to 2010 subsidence has happened between 3 to 4.1 meters especially in Jakarta coastal area. Two major causes of the subsidence are identified. The first major cause is a result of erecting weight building such as hotels, appartments, and various human activities buildings. The second major cause is extracting ground water from aquifers bellow Jakarta land due to water deep wells down to the aquifer and traditional shallow water well of shallow or subsurface uncovered ground water. Weighter building and higher debit of water flow from deep water wells has fastened and deepened the land subsidence. Continuous measurement of land subsidence by means of geodetic as well as geophysical earth behaviour measurements need to be performed to monitor the rate, location as well as mapping of the land subsidence.

24 CFR 982.504 - Voucher tenancy: Payment standard for family in restructured subsidized multifamily project.

Science.gov (United States)

2010-04-01

... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Voucher tenancy: Payment standard... ASSISTANCE: HOUSING CHOICE VOUCHER PROGRAM Rent and Housing Assistance Payment § 982.504 Voucher tenancy: Payment standard for family in restructured subsidized multifamily project. (a) This section applies to...

Barriers and facilitators to healthy eating and disease self-management among older adults residing in subsidized housing.

Science.gov (United States)

Petroka, Katherine; Campbell-Bussiere, Rania; Dychtwald, Dan K; Milliron, Brandy-Joe

2017-09-01

As adults transition into older ages, meeting age-specific dietary recommendations can become increasingly challenging, especially for low-income seniors who reside in publicly subsidized rental housing. The primary objectives of this study were to: 1) identify barriers and facilitators to healthy eating and self-management of nutrition-related chronic illnesses experienced by low-income seniors residing in a subsidized housing setting; and 2) assess the interest in community nutrition programming among low-income seniors residing in a subsidized housing setting. A qualitative study design, using food focus groups and food pantry observations, was used. Participants included 24 male and female senior adults, between 65 and 75 years of age, residing in a subsidized housing community in Philadelphia, PA. This setting also included the unique features of a community garden and food pantry. Data were manually analyzed using a content analysis approach, which included familiarization, identification of themes, categorization and interpretation; and verified using NVivo 10. Personal barriers, including food cost and accessibility, physical limitations, desire for convenience, and low self-efficacy to change dietary habits, inhibited motivation to change. External barriers in the food environment, including lack of transportation and distance of markets to access fresh produce, were commonly cited; as well as negative influences of the internal environment, such as the presence of vending machines, common cultural cooking and eating practices, and the lack of social cohesion. Facilitators focused on food preparation and recipe adaptation. Participants expressed an interest in learning more about food, nutrition, and health through community-based programming.

Ground Subsidence over Beijing-Tianjin-Hebei Region during Three Periods of 1992 to 2014 Monitored by Interferometric SAR

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ZHANG Yonghong

2016-09-01

Full Text Available The Beijing-Tianjin-Hebei region suffers the most serious ground subsidence in China, which has caused huge economic losses every year. Therefore, ground subsidence was listed as an important mission in the project of geographic conditions monitoring over Beijing-Tianjin-Hebei launched by the National Administration of Surveying, Mapping and Geoinformation in 2013. In this paper, we propose a methodology of ground subsidence monitoring over wide area, which is entitled "multiple master-image coherent target small-baseline interferometric SAR (MCTSB-InSAR". MCTSB-InSAR is an improved time series InSAR technique with some unique features. SAR datasets used for ground subsidence monitoring over the Beijing-Tianjin-Hebei region include ERS-1/2 SAR images acquired between 1992 to 2000, ENVISAT ASAR images acquired between 2003 to 2010 and RADARSAT-2 images acquired between 2012 to 2014. This research represents a first ever effort on mapping ground subsidence over Beijing-Tianjin-Hebei region and over such as a long time span in China. In comparison with more than 120 leveling measurements collected in Beijing and Tianjin, the derived subsidence velocity has the accuracy of 8.7mm/year (1992—2000, 4.7mm/year (2003—2010, and 5.4mm/year (2012—2014 respectively. The spatial-temporal characteristics of the development of ground subsidence in Beijing and Tianjin are analyzed. In general, ground subsidence in Beijing kept continuously expanding in the period of 1992 to 2014. While, ground subsidence in Tianjin had already been serious in 1990s, had dramatically expanded during 2000s, and started to alleviate in recent years. The monitoring result is of high significance for prevention and mitigation of ground subsidence disaster, for making development plan, for efficient and effective utilization of water resource, and for adjustment of economic framework of this region. The result also indicates the effectiveness and reliability of the MCTSB

Lithosphere structure and subsidence evolution of the conjugate S-African and Argentine margins

Science.gov (United States)

Dressel, Ingo; Scheck-Wenderoth, Magdalena; Cacace, Mauro; Götze, Hans-Jürgen; Franke, Dieter

2016-04-01

The bathymetric evolution of the South Atlantic passive continental margins is a matter of debate. Though it is commonly accepted that passive margins experience thermal subsidence as a result of lithospheric cooling as well as load induced subsidence in response to sediment deposition it is disputed if the South Atlantic passive margins were affected by additional processes affecting the subsidence history after continental breakup. We present a subsidence analysis along the SW African margin and offshore Argentina and restore paleobathymetries to assess the subsidence evolution of the margin. These results are discussed with respect to mechanisms behind margin evolution. Therefore, we use available information about the lithosphere-scale present-day structural configuration of these margins as a starting point for the subsidence analysis. A multi 1D backward modelling method is applied to separate individual subsidence components such as the thermal- as well as the load induced subsidence and to restore paleobathymetries for the conjugate margins. The comparison of the restored paleobathymetries shows that the conjugate margins evolve differently: Continuous subsidence is obtained offshore Argentina whereas the subsidence history of the SW African margin is interrupted by phases of uplift. This differing results for both margins correlate also with different structural configurations of the subcrustal mantle. In the light of these results we discuss possible implications for uplift mechanisms.

Subsidizing R&D cooperatives

NARCIS (Netherlands)

Hinloopen, J.

2001-01-01

A framework is developed with which the implementation of two commonly used R&D-stimulating policies can be evaluated: providing R&D subsidies and sustaining the formation of R&D cooperatives. Subsidized R&D cooperatives can also be analyzed. The analysis shows that providing R&D subsidies is more

Proceedings of the 1985 conference on coal mine subsidence in the Rocky Mountain Region

Energy Technology Data Exchange (ETDEWEB)

Hynes, J.L. (ed.)

1986-01-01

A total of 20 papers were presented at the conference on the following subjects: reclamation projects; geological surveys; history and evolution of mining; essential components of mine subsidence; subsidence related damage; core recovery of poorly consolidated materials; evaluation of subsurface conditions; remote video inspection of abandoned coal mines; use of progressive failure model for subsidence prediction; chimney subsidence sinkhole development; analytical methods of subsidence prediction; monitoring networks; architectural mitigating measures; backfilling; awareness and planning; administrative aspects; mine subsidence insurance; risk management.

What’s the Score? Walkable Environments and Subsidized Households

Directory of Open Access Journals (Sweden)

Young-Jae Kim

2016-04-01

Full Text Available Neighborhood walkability can influence individual health, social interactions, and environmental quality, but the relationships between subsidized households and their walkable environment have not been sufficiently examined in previous empirical studies. Focusing on two types of subsidized housing developments (Low-Income Housing Tax Credit (LIHTC and Public Housing (PH in Austin, Texas, this study evaluates the neighborhood walkability of place-based subsidized households, utilizing objectively measured Walk Score and walking-related built environment data. We also used U.S. Census block group data to account for the socio-demographic covariates. Based on various data, we employed bivariate and multivariate analyses to specify the relationships between subsidized households and their neighborhood walkable environment. The results of our bivariate analyses show that LIHTC households tend to be located in car-dependent neighborhoods and have more undesirable walking-related built environment conditions compared with non-LIHTC neighborhoods. Our regression results also represent that LIHTC households are more likely to be exposed to neighborhoods with low Walk Score, less sidewalk coverage, and more highways and major roads, while there are no significant associations for PH households. These findings imply that more attention and effort toward reducing the inequitable distributions of walkable neighborhood features supporting rather than hindering healthy lifestyles must be provided to subsidized households.

Land Subsidence Prediction by Back Calculation Method and its Effects on Sewage Network

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Mohammad Mohsen Toufigh

2009-03-01

Full Text Available Groundwater overdraft is one of the main reasons of land subsidence. Differential subsidence leads to earth fissures and damages to structures, roads, railroads, pipelines, irrigation canals, and sewage networks. In order to simulate land subsidence due to groundwater overdraft, a fully coupled finite element consolidation model was developed. Formulation of finite element was based on Biot three-dimensional consolidation theory. Land subsidence studies inRafsanjanCitywere conducted by collecting and analyzing data on geology, geophysics, hydrology, soil properties, and observed land subsidence. Due to lack of sufficient experimental data about different soil profiles, land subsidence monitoring and back calculation were used in several spots to obtain the necessary data for use in other places. A computer model was finally developed to predict the subsidence of the city and its effects on the sewage network were studied.

Geomechanics of subsidence above single and multi-seam coal mining

Directory of Open Access Journals (Sweden)

A.M. Suchowerska Iwanec

2016-06-01

Full Text Available Accurate prediction of surface subsidence due to the extraction of underground coal seams is a significant challenge in geotechnical engineering. This task is further compounded by the growing trend for coal to be extracted from seams either above or below previously extracted coal seams, a practice known as multi-seam mining. In order to accurately predict the subsidence above single and multi-seam longwall panels using numerical methods, constitutive laws need to appropriately represent the mechanical behaviour of coal measure strata. The choice of the most appropriate model is not always straightforward. This paper compares predictions of surface subsidence obtained using the finite element method, considering a range of well-known constitutive models. The results show that more sophisticated and numerically taxing constitutive laws do not necessarily lead to more accurate predictions of subsidence when compared to field measurements. The advantages and limitations of using each particular constitutive law are discussed. A comparison of the numerical predictions and field measurements of surface subsidence is also provided.

Traces of warping subsided tectonic blocks on Miranda, Enceladus, Titan

Science.gov (United States)

Kochemasov, G.

2007-08-01

Icy satellites of the outer Solar system have very large range of sizes - from kilometers to thousands of kilometers. Bodies less than 400-500 km across have normally irregular shapes , often presenting simple Plato's polyhedrons woven by standing inertiagravity waves (see an accompanying abstract of Kochemasov). Larger bodies with enhanced gravity normally are rounded off and have globular shapes but far from ideal spheres. This is due to warping action of inertia-gravity waves of various wavelengths origin of which is related to body movements in elliptical keplerian orbits with periodically changing accelerations (alternating accelerations cause periodically changing forces acting upon a body what means oscillations of its spheres in form of standing warping waves). The fundamental wave 1 and its first overtone wave 2 produce ubiquitous tectonic dichotomy - two segmental structure and tectonic sectoring superimposed on this dichotomy. Two kinds of tectonic blocks (segments and sectors) are formed: uplifted (+) and subsided (-). Uplifting means increasing planetary radius of blocks, subsiding - decreasing radius (as a sequence subsiding blocks diminishing their surfaces must be warped, folded, wrinkled; uplifting blocks increasing their surfaces tend to be deeply cracked, fallen apart). To level changing angular momenta of blocks subsided areas are filled with denser material than uplifted ones (one of the best examples is Earth with its oceanic basins filled with dense basalts and uplifted continents built of less dense on average andesitic material). Icy satellites follow the same rule. Their warped surfaces show differing chemistries or structures of constructive materials. Uplifted blocks are normally built with light (by color and density) water ice. Subsided blocks - depressions, "seas', "lakes", coronas - by somewhat denser material differing in color from water ice (very sharply - Iapetus, moderately - Europa, slightly - many saturnian satellites). A very

Subsidence of the South Polar Terrain and global tectonic of Enceladus

Science.gov (United States)

Czechowski, Leszek

2016-04-01

compressional surface features do not have to be dominant. The SPT is compressed, so "tiger stripes" could exist for long time. Only after significant subsidence (below 1200 m) the regime of stresses changes to compressional. We suppose that it means the end of activity in a given region. Acknowledgments This work was partially supported by the National Science Centre (grant 2011/01/B/ST10/06653). Computer resources of Interdisciplinary Centre for Mathematical and Computational Modeling of University of Warsaw were also used in the research References [1] Spencer, J. R., et al. (2009) Enceladus: An Active Cryovolcanic Satellite, in: M.K. Dougherty et al. (eds.), Saturn from Cassini-Huygens, Springer Science, p. 683. [2] Czechowski L. (2015) Mass loss as a driving mechanism of tectonics of Enceladus 46th Lunar and Planetary Science Conference 2030.pdf. [3] Czechowski, L., (2014) Some remarks on the early evolution of Enceladus. Planet. Sp. Sc. 104, 185-199.

Monitoring ground subsidence in Shanghai maglev area using two kinds of SAR data

Science.gov (United States)

Wu, Jicang; Zhang, Lina; Chen, Jie; Li, Tao

2012-11-01

Shanghai maglev is a very fast traffic tool, so it is very strict with the stability of the roadbed. However, the ground subsidence is a problem in Shanghai because of the poor geological condition and human-induced factors. So it is necessary to monitor ground subsidence in the area along the Shanghai maglev precisely and frequently. Traditionally, a precise levelling method is used to survey along the track. It is expensive and time consuming, and can only get the ground subsidence information on sparse benchmarks. Recently, the small baseline differential SAR technique plays a valuable part in monitoring ground subsidence, which can extract ground subsidence information with high spatial resolution in a wide area. In this paper, L-band ALOS PALSAR data and C-band Envisat ASAR data are used to extract ground subsidence information using the SBAS method in the Shanghai maglev area. The results show that the general pattern of ground subsidence from InSAR processing of two differential bands of SAR images is similar. Both results show that there is no significant ground subsidence on the maglev line. Near the railway line, there are a few places with subsidence rates at about -20 mm/y or even more, such as Chuansha town, the junction of the maglev and Waihuan road.

Areas of ground subsidence due to geofluid withdrawal

Energy Technology Data Exchange (ETDEWEB)

Grimsrud, G.P.; Turner, B.L.; Frame, P.A.

1978-08-01

Detailed information is provided on four geothermal areas with histories of subsidence. These were selected on the basis of: physical relevance of subsidence areas to high priority US geothermal sites in terms of withdrawn geofluid type, reservoir depth, reservoir geology and rock characteristics, and overburden characteristics; and data completeness, quality, and availability. The four areas are: Chocolate Bayou, Raft River Valley, Wairakei, and the Geysers. (MHR)

Comparison of estimated and background subsidence rates in Texas-Louisiana geopressured geothermal areas

Energy Technology Data Exchange (ETDEWEB)

Lee, L.M.; Clayton, M.; Everingham, J.; Harding, R.C.; Massa, A.

1982-06-01

A comparison of background and potential geopressured geothermal development-related subsidence rates is given. Estimated potential geopressured-related rates at six prospects are presented. The effect of subsidence on the Texas-Louisiana Gulf Coast is examined including the various associated ground movements and the possible effects of these ground movements on surficial processes. The relationships between ecosystems and subsidence, including the capability of geologic and biologic systems to adapt to subsidence, are analyzed. The actual potential for environmental impact caused by potential geopressured-related subsidence at each of four prospects is addressed. (MHR)

Study on Land Subsidence Incangzhou Area Basedon SENTINEL-1A/B Data

Science.gov (United States)

Zhou, H.; Wang, Y.; Yan, S.

2017-09-01

This paper, obtaining 39scenesof images of the Sentinel-1 A/B, monitored the Cangzhou area subsidence from Mar. 2015 to Dec. 2016 basing on using PS-InSAR technique. The annual average subsidence rate and accumulative subsidence were obtained. The results showed that the ground surface of Xian County,Cang County, Cangzhou urban area had a rebound trend; Qing County, the east of Cang County ,the west of Nanpi County and Dongguang County appeared obvious subsidence, and the accumulated subsidence in Hezhuang village of Dongguang County reached 47 mm. And from that the main reason leading to these obvious subsidence was over-exploitation of ground-water. At last, it analyzed the settlement of the High-Speed Railway (HR) which was north from the Machang town of QingCounty and south to the Lian town of Dongguang County in Cangzhou.The relative deformation of the HR between the two sections which was Lierzhuang village of Cang County and Chenxin village of Nanpi County arrived at 30 mm. Moreover, this paper discussed the application of Sentinel-1 A/B SAR images in monitoring urban land subsidence and the results provided important basic data for the relevant departments.

The analysis of subsidence associated with geothermal development. Volume 1. Handbook

Energy Technology Data Exchange (ETDEWEB)

Atherton, R.W.; Finnemore, E.J.; Gillam, M.L.

1976-09-01

This study evaluates the state of knowledge of subsidence associated with geothermal development, and provides preliminary methods to assess the potential of land subsidence for any specific geothermal site. The results of this study are presented in three volumes. Volume 1 is designed to serve as a concise reference, a handbook, for the evaluation of the potential for land subsidence from the development of geothermal resources.

A new soil mechanics approach to quantify and predict land subsidence by peat compression

NARCIS (Netherlands)

Koster, K.; Erkens, G.; Zwanenburg, C.

2016-01-01

Land subsidence threatens many coastal areas. Quantifying current and predicting future subsidence are essential to sustain the viability of these areas with respect to rising sea levels. Despite its scale and severity, methods to quantify subsidence are scarce. In peat-rich subsidence hot spots,

Experimental 3-D modelling of surface subsidence affected by underground mining activities

Czech Academy of Sciences Publication Activity Database

Trčková, Jiřina

2009-01-01

Roč. 109, č. 12 (2009), s. 739-744 ISSN 0038-223X R&D Projects: GA AV ČR IAA2119402 Institutional research plan: CEZ:AV0Z30460519 Keywords : undermining * subsidence of surface * 3-D experimental model Subject RIV: DO - Wilderness Conservation Impact factor: 0.216, year: 2009

Relating large-scale subsidence to convection development in Arctic mixed-phase marine stratocumulus

Science.gov (United States)

Young, Gillian; Connolly, Paul J.; Dearden, Christopher; Choularton, Thomas W.

2018-02-01

Large-scale subsidence, associated with high-pressure systems, is often imposed in large-eddy simulation (LES) models to maintain the height of boundary layer (BL) clouds. Previous studies have considered the influence of subsidence on warm liquid clouds in subtropical regions; however, the relationship between subsidence and mixed-phase cloud microphysics has not specifically been studied. For the first time, we investigate how widespread subsidence associated with synoptic-scale meteorological features can affect the microphysics of Arctic mixed-phase marine stratocumulus (Sc) clouds. Modelled with LES, four idealised scenarios - a stable Sc, varied droplet (Ndrop) or ice (Nice) number concentrations, and a warming surface (representing motion southwards) - were subjected to different levels of subsidence to investigate the cloud microphysical response. We find strong sensitivities to large-scale subsidence, indicating that high-pressure systems in the ocean-exposed Arctic regions have the potential to generate turbulence and changes in cloud microphysics in any resident BL mixed-phase clouds.Increased cloud convection is modelled with increased subsidence, driven by longwave radiative cooling at cloud top and rain evaporative cooling and latent heating from snow growth below cloud. Subsidence strengthens the BL temperature inversion, thus reducing entrainment and allowing the liquid- and ice-water paths (LWPs, IWPs) to increase. Through increased cloud-top radiative cooling and subsequent convective overturning, precipitation production is enhanced: rain particle number concentrations (Nrain), in-cloud rain mass production rates, and below-cloud evaporation rates increase with increased subsidence.Ice number concentrations (Nice) play an important role, as greater concentrations suppress the liquid phase; therefore, Nice acts to mediate the strength of turbulent overturning promoted by increased subsidence. With a warming surface, a lack of - or low - subsidence

A model-based analysis of biomethane production in the Netherlands and the effectiveness of the subsidization policy under uncertainty

International Nuclear Information System (INIS)

Eker, Sibel; Daalen, Els van

2015-01-01

Biomethane is a renewable alternative to natural gas. It has the potential to increase the sustainability of the energy system and to help deal with supply problems. However, several factors make the future of biomethane production complex and uncertain, such as resource availability, demand, capacity installation, profitability and the competition between the biomethane and electricity sectors for sharing the available biogas and biomass resources. In this research, we study the dynamics of the Dutch biomethane production and analyze the effects of subsidization policy with a system dynamics model. The policy is tested under uncertainty with respect to three conflicting objectives, namely maximizing production and emission reduction, and minimizing costs. According to the results, the subsidization is crucial to develop biomethane production, and the performance of the policy is enhanced in terms of robustness and of meeting all three objectives satisfactorily when the policy is implemented for a long time, with relatively low subsidy prices. Besides, the subsidization policy is found to be most vulnerable to the producers’ uncertain investment response to profitability. In future research, different policy options such as subsidizing other biomass-based renewable energy options and policies affecting the biomethane demand can be tested

Mine subsidence control projects associated with solid waste disposal facilities

International Nuclear Information System (INIS)

Wood, R.M.

1994-01-01

Pennsylvania environmental regulations require applicant's for solid waste disposal permits to provide information regarding the extent of deep mining under the proposed site, evaluations of the maximum subsidence potential, and designs of measures to mitigate potential subsidence impact on the facility. This paper presents three case histories of deep mine subsidence control projects at solid waste disposal facilities. Each case history presents site specific mine grouting project data summaries which include evaluations of the subsurface conditions from drilling, mine void volume calculations, grout mix designs, grouting procedures and techniques, as well as grout coverage and extent of mine void filling evaluations. The case studies described utilized basic gravity grouting techniques to fill the mine voids and fractured strata over the collapsed portions of the deep mines. Grout mixtures were designed to achieve compressive strengths suitable for preventing future mine subsidence while maintaining high flow characteristics to penetrate fractured strata. Verification drilling and coring was performed in the grouted areas to determine the extent of grout coverage and obtain samples of the in-place grout for compression testing. The case histories presented in this report demonstrate an efficient and cost effective technique for mine subsidence control projects

Research Program Overview

Science.gov (United States)

PEER logo Pacific Earthquake Engineering Research Center home about peer news events research products laboratories publications nisee b.i.p. members education FAQs links research Research Program Overview Tall Buildings Initiative Transportation Research Program Lifelines Program Concrete Grand

Application of InSAR and Gravimetry for Land Subsidence Hazard Zoning in Aguascalientes, Mexico

Directory of Open Access Journals (Sweden)

Jesús Pacheco-Martínez

2015-12-01

Full Text Available In this work we present an application of InSAR and gravimetric surveys for risk management related to land subsidence and surface ground faulting generation. A subsidence velocity map derived from the 2007–2011 ALOS SAR imagery and a sediment thicknesses map obtained from the inversion of gravimetric data were integrated with a surface fault map to produce a subsidence hazard zoning in the city of Aguascalientes, Mexico. The resulting zoning is presented together with specific recommendations about geotechnical studies needed for further evaluation of surface faulting in these hazard zones. The derived zoning map consists in four zones including null hazard (stable terrain without subsidence, low hazard (areas prone to subsidence, medium hazard (zones with subsidence and high hazard (zones with surface faulting. InSAR results displayed subsidence LOS velocities up to 10 cm/year and two subsidence areas unknown before this study. Gravimetric results revealed that the thicker sediment sequence is located toward north of Aguascalientes City reaching up to 600 m in thickness, which correspond to a high subsidence LOS velocity zone (up to 6 cm/year.

Land subsidence threats and its management in the North Coast of Java

Science.gov (United States)

Sarah, D.; Soebowo, E.

2018-02-01

Cities on the north coast of Java such as Jakarta, Semarang, Pekalongan, and Surabaya are vulnerable to environmental pressures such as sea level change and land subsidence. Land subsidence can be caused by natural and anthropogenic processes. Geologically, the north coastal plain of Java consists of unconsolidated Holocene alluvial deposit. The recent alluvial deposit is prone to compaction, and further aggravated by anthropogenic forces such as groundwater extraction and land development. Understanding the complex interaction of natural and manmade factors is essential to establish mitigation strategy. Although the impacts of land subsidence are widely felt, many do not realize that land subsidence is taking place. This paper presents a brief review of the land subsidence threats in the North coast of Java and proposes a recommendation for suitable management response.

Resolving the Subsidence Anomaly of the East Tasman Plateau Using New Insights from the Cascade Seamount, Southwest Tasman Sea

Science.gov (United States)

Vorsanger, S. L.; Scher, H.; Johnson, S.; Mundana, R.; Sauermilch, I.; Duggan, B.; Whittaker, J. M.

2017-12-01

The Cascade Seamount is a wave-planated feature located on the microcontinent of the East Tasman Plateau (ETP). The minimum subsidence rate of the Seamount and the ETP can be estimated by dividing the present-day depth of the wave-cut surface (640 m) by the age of Cascade Seamount basalts as determined by potassium-argon (K-Ar) dating (33.4 and 36 Ma). This approach yields a subsidence rate of 18 m/Myr. However, significantly more rapid subsidence rates of the East Tasman Plateau (ETP) — upon which the Cascade Seamount rests — since the Eocene-Oligocene transition have been proposed utilizing a nearby sediment core, Ocean Drilling Program (ODP) Site 1172. Late Eocene paleodepths determined by Stickley et al. (2004) using sedimentological and biostratigraphic techniques, indicate a subsidence rate of 85 m/Myr for the ETP. These two results present a paradox, which implies that the ETP subsided at a rate greater than the Seamount itself, over the same time interval. It also implies that the seamount formed above sea level. The subsidence ambiguity may be attributed to the presence of a turbidity current deposit in the sediment core, or uncertainty in the age and/or location of the K-Ar dated basalts of the Cascade Seamount. Statistical analysis of the published grain size measurements will be used to test for the presence of a turbidity current deposit in ODP Site 1172. We will also measure 87Sr/86Sr ratios of marine carbonate samples from conglomerates obtained from the Cascade Seamount during the August 2016 RV Investigator voyage (IN2016_E01) to confirm the age of the wave planated surfaces by Strontium Isotope Stratigraphy. This will allow for a more robust calculation for the subsidence of the ETP which was a critical barrier in the Tasmanian Gateway that allowed for the formation of the Antarctic Circumpolar Current.

Correlating the subsidence pattern and land use in Bandung, Indonesia with both Sentinel-1/2 and ALOS-2 satellite images

Science.gov (United States)

Du, Zheyuan; Ge, Linlin; Ng, Alex Hay-Man; Zhu, Qinggaozi; Yang, Xihua; Li, Liyuan

2018-05-01

Continuous research has been conducted in Bandung City, West Java province, Indonesia over the past two decades. Previous studies carried out in a regional-scale might be useful for estimating the correlation between land subsidence and groundwater extraction, but inadequate for local safety management as subsidence may vary over different areas with detailed characters. This study is focused primarily on subsidence phenomenon in local, patchy and village scales, respectively, with Sentinel-1 and ALOS-2 dataset acquired from September 2014 to July 2017. The Sentinel-1 derived horizontal movement map confirmed that the vertical displacement is dominant of the Line-of-Sight (LoS) subsidence. Moreover, both Sentinel-1 and ALOS-2 derived InSAR measurements were cross-validated with each other. In order to understand the subsidence in a more systematic way, six 10-cm subsidence zones have been selected known as Zone A-F. Further analyses conducted over multiple scales show that industrial usage of groundwater is not always the dominant factor that causes the land subsidence and indeed it does not always create large land subsidence either. Regions experiencing subsidence is due to a combined impact of a number of factors, e.g., residential, industrial or agricultural activities. The outcome of this work not only contributes to knowledge on efficient usage of the satellite-based monitoring networks, but also assists developing the best hazard mitigation plans. In the future work, as we cannot draw the conclusion which is the dominant factor within each sub-zone due to the lack of statistical data, e.g., the groundwater consumption rates per square kilometre for different land types, further datasets are still needed to examine the core factor.

Rapid groundwater-related land subsidence in Yemen observed by multi-temporal InSAR

KAUST Repository

Abdullin, Ayrat

2015-04-01

Several basins in Yemen are suffering from a rapid drawdown of groundwater, which is the most important water source for agricultural irrigation, industry and domestic use. However, detailed geodetic measurements in the region have been lacking and the extent and magnitude of groundwater-related land subsidence has been poorly known. We used 13 ascending ALOS and 15 descending Envisat images to study land subsidence of several basins in Yemen, with a special focus on the Sana\\'a and Mabar basins. From multitemporal synthetic aperture radar interferometric analysis (persistent scatterers (PS) and small baseline subsets (SBAS)) we examined the spatio-temporal behavior of the subsidence induced by depletion of groundwater aquifer systems from November 2003 to February 2011. In the interferometric data processing, we carefully chose interferogram pairs to minimize spatial and temporal decorrelation, because of high subsidence rates and the type of land cover. Our results show that the spatial pattern of subsidence remained quite stable during the observation period in both the Sana\\'a and Mabar basins. In the Sana\\'a basin, the maximum subsidence rate exceeded 14 cm/year in the radar line-of-sight (LOS) direction between 2003 and 2008 in an agricultural area just north of Sana\\'a city, where water wells have been drying up according to the well data. The subsidence rate was lower in the urban areas, or approximately 1 cm/year, exhibiting annual variations. The main subsidence was found in the center and southern parts of the city, while deformation in the northern part is less obvious. For the Mabar basin, the subsidence rate exceeded 30 cm/year in the agricultural area north of the town of Mabar during 2007 - 2011. The southern part of the Mabar basin also experienced high subsidence rates, although somewhat lower than to the north. Excessive water pumping is the main cause of the ground subsidence and it has already led to extensive ground fracturing at the edge

Rapid groundwater-related land subsidence in Yemen observed by multi-temporal InSAR

Science.gov (United States)

Abdullin, Ayrat; Xu, Wenbin; Kosmicki, Maximillian; Jonsson, Sigurjon

2015-04-01

Several basins in Yemen are suffering from a rapid drawdown of groundwater, which is the most important water source for agricultural irrigation, industry and domestic use. However, detailed geodetic measurements in the region have been lacking and the extent and magnitude of groundwater-related land subsidence has been poorly known. We used 13 ascending ALOS and 15 descending Envisat images to study land subsidence of several basins in Yemen, with a special focus on the Sana'a and Mabar basins. From multitemporal synthetic aperture radar interferometric analysis (persistent scatterers (PS) and small baseline subsets (SBAS)) we examined the spatio-temporal behavior of the subsidence induced by depletion of groundwater aquifer systems from November 2003 to February 2011. In the interferometric data processing, we carefully chose interferogram pairs to minimize spatial and temporal decorrelation, because of high subsidence rates and the type of land cover. Our results show that the spatial pattern of subsidence remained quite stable during the observation period in both the Sana'a and Mabar basins. In the Sana'a basin, the maximum subsidence rate exceeded 14 cm/year in the radar line-of-sight (LOS) direction between 2003 and 2008 in an agricultural area just north of Sana'a city, where water wells have been drying up according to the well data. The subsidence rate was lower in the urban areas, or approximately 1 cm/year, exhibiting annual variations. The main subsidence was found in the center and southern parts of the city, while deformation in the northern part is less obvious. For the Mabar basin, the subsidence rate exceeded 30 cm/year in the agricultural area north of the town of Mabar during 2007 - 2011. The southern part of the Mabar basin also experienced high subsidence rates, although somewhat lower than to the north. Excessive water pumping is the main cause of the ground subsidence and it has already led to extensive ground fracturing at the edge of some

Analysis of Land Subsidence Monitoring in Mining Area with Time-Series Insar Technology

Science.gov (United States)

Sun, N.; Wang, Y. J.

2018-04-01

Time-series InSAR technology has become a popular land subsidence monitoring method in recent years, because of its advantages such as high accuracy, wide area, low expenditure, intensive monitoring points and free from accessibility restrictions. In this paper, we applied two kinds of satellite data, ALOS PALSAR and RADARSAT-2, to get the subsidence monitoring results of the study area in two time periods by time-series InSAR technology. By analyzing the deformation range, rate and amount, the time-series analysis of land subsidence in mining area was realized. The results show that InSAR technology could be used to monitor land subsidence in large area and meet the demand of subsidence monitoring in mining area.

Land subsidence in the San Joaquin Valley, California, USA, 2007-14

Science.gov (United States)

Sneed, Michelle; Brandt, Justin

2015-01-01

Rapid land subsidence was recently measured using multiple methods in two areas of the San Joaquin Valley (SJV): between Merced and Fresno (El Nido), and between Fresno and Bakersfield (Pixley). Recent land-use changes and diminished surface-water availability have led to increased groundwater pumping, groundwater-level declines, and land subsidence. Differential land subsidence has reduced the flow capacity of water-conveyance systems in these areas, exacerbating flood hazards and affecting the delivery of irrigation water. Vertical land-surface changes during 2007–2014 were determined by using Interferometric Synthetic Aperture Radar (InSAR), Continuous Global Positioning System (CGPS), and extensometer data. Results of the InSAR analysis indicate that about 7600 km2 subsided 50–540 mm during 2008–2010; CGPS and extensometer data indicate that these rates continued or accelerated through December 2014. The maximum InSAR-measured rate of 270 mm yr−1 occurred in the El Nido area, and is among the largest rates ever measured in the SJV. In the Pixley area, the maximum InSAR-measured rate during 2008–2010 was 90 mm yr−1. Groundwater was an important part of the water supply in both areas, and pumping increased when land use changed or when surface water was less available. This increased pumping caused groundwater-level declines to near or below historical lows during the drought periods 2007–2009 and 2012–present. Long-term groundwater-level and land-subsidence monitoring in the SJV is critical for understanding the interconnection of land use, groundwater levels, and subsidence, and evaluating management strategies that help mitigate subsidence hazards to infrastructure while optimizing water supplies.

Historic, Recent, and Future Subsidence, Sacramento-San Joaquin Delta, California, USA

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Steven J Deverel

2010-08-01

Full Text Available To estimate and understand recent subsidence, we collected elevation and soils data on Bacon and Sherman islands in 2006 at locations of previous elevation measurements. Measured subsidence rates on Sherman Island from 1988 to 2006 averaged 1.23 cm/year (0.5 in/yr and ranged from 0.7 to 1.7 cm/year (0.3 to 0.7 in/year. Subsidence rates on Bacon Island from 1978 to 2006 averaged 2.2 cm/year (0.9 in/yr and ranged from 1.5 to 3.7 cm/year (0.6 to 1.5 in/yr. Changing land-management practices and decreasing soil organic matter content have resulted in decreasing subsidence rates. On Sherman Island, rates from 1988 to 2006 were about 35% of 1910 to 1988 rates. For Bacon Island, rates from 1978 to 2006 were about 40% less than the 1926-1958 rates. To help understand causes and estimate future subsidence, we developed a subsidence model, SUBCALC, that simulates oxidation and carbon losses, consolidation, wind erosion, and burning and changing soil organic matter content. SUBCALC results agreed well with measured land-surface elevation changes. We predicted elevation decreases from 2007 to 2050 will range from a few centimeters to over 1.3 m (4.3 ft. The largest elevation declines will occur in the central Sacramento-San Joaquin Delta. From 2007 to 2050, the most probable estimated increase in volume below sea level is 349,956,000 million cubic meters (281,300 acre-feet. Consequences of this continuing subsidence include increased drainage loads of water quality constituents of concern, seepage onto islands, and decreased arability.

Spatial prediction of ground subsidence susceptibility using an artificial neural network.

Science.gov (United States)

Lee, Saro; Park, Inhye; Choi, Jong-Kuk

2012-02-01

Ground subsidence in abandoned underground coal mine areas can result in loss of life and property. We analyzed ground subsidence susceptibility (GSS) around abandoned coal mines in Jeong-am, Gangwon-do, South Korea, using artificial neural network (ANN) and geographic information system approaches. Spatial data of subsidence area, topography, and geology, as well as various ground-engineering data, were collected and used to create a raster database of relevant factors for a GSS map. Eight major factors causing ground subsidence were extracted from the existing ground subsidence area: slope, depth of coal mine, distance from pit, groundwater depth, rock-mass rating, distance from fault, geology, and land use. Areas of ground subsidence were randomly divided into a training set to analyze GSS using the ANN and a test set to validate the predicted GSS map. Weights of each factor's relative importance were determined by the back-propagation training algorithms and applied to the input factor. The GSS was then calculated using the weights, and GSS maps were created. The process was repeated ten times to check the stability of analysis model using a different training data set. The map was validated using area-under-the-curve analysis with the ground subsidence areas that had not been used to train the model. The validation showed prediction accuracies between 94.84 and 95.98%, representing overall satisfactory agreement. Among the input factors, "distance from fault" had the highest average weight (i.e., 1.5477), indicating that this factor was most important. The generated maps can be used to estimate hazards to people, property, and existing infrastructure, such as the transportation network, and as part of land-use and infrastructure planning.

An Integrated Approach for the Assessment of the Natural and Anthropogenic Controls on Land Subsidence in the Kingdom of Saudi Arabia

Science.gov (United States)

Othman, A.; Sultan, M.; Ahmed, M.; Alharbi, T.; Gebremichael, E.; Emil, M.

2015-12-01

Recent land subsidence incidences in the Kingdom of Saudi Arabia (KSA) resulted in loss in life and property. In this study, an integrated approach is adopted to accomplish the following: (1) map the spatial distribution of areas that are witnessing land subsidence, (2) quantify the rates of land subsidence, and (3) identify the factors causing the observed subsidence. A three-fold approach is applied: (1) use of interferometric techniques to assess the spatial distribution of land subsidence and to quantify the rates of subsidence, (2) generate a GIS database to encompass all relevant data and derived products, and (3) correlate findings from the radar exercise with relevant spatial and temporal datasets (e.g., remote sensing, geology, fluid extraction rates, distribution of urban areas, etc.). Three main areas were selected: (1) central and northern parts of the KSA, (2) areas surrounding the Ghawar oil/gas field, and (3) the Harrat Lunayyir volcanic field. Applications of two-pass, three-pass, and SBAS radar interferometric techniques over central KSA revealed the following: (1) subsidence rates of up to -15 mm/yr were detected; the spatial distribution of the subsided areas that were extracted using the various interferometric techniques are similar, (2) subsided areas correlated spatially with the distribution of: (a) areas with high groundwater extraction rates as evidenced from the analysis of field and Gravity Recovery and Climate Experiment (GRACE) data, (b) agricultural plantations as evidenced from the analysis of field and temporal Landsat data, (c) urban areas (e.g., Buraydah City), (d) outcrops of carbonates and anhydrite formations (e.g., Khuff and Jilh formations), (3) subsidence could be related to more than one parameter. Similar research activities are underway in northern KSA and in areas surrounding the Ghawar oil/gas and the Harrat Lunayyir volcanic fields to assess the distribution and factors controlling land deformation in those areas.

Imaging Land Subsidence Induced by Groundwater Extraction in Beijing (China Using Satellite Radar Interferometry

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Mi Chen

2016-06-01

Full Text Available Beijing is one of the most water-stressed cities in the world. Due to over-exploitation of groundwater, the Beijing region has been suffering from land subsidence since 1935. In this study, the Small Baseline InSAR technique has been employed to process Envisat ASAR images acquired between 2003 and 2010 and TerraSAR-X stripmap images collected from 2010 to 2011 to investigate land subsidence in the Beijing region. The maximum subsidence is seen in the eastern part of Beijing with a rate greater than 100 mm/year. Comparisons between InSAR and GPS derived subsidence rates show an RMS difference of 2.94 mm/year with a mean of 2.41 ± 1.84 mm/year. In addition, a high correlation was observed between InSAR subsidence rate maps derived from two different datasets (i.e., Envisat and TerraSAR-X. These demonstrate once again that InSAR is a powerful tool for monitoring land subsidence. InSAR derived subsidence rate maps have allowed for a comprehensive spatio-temporal analysis to identify the main triggering factors of land subsidence. Some interesting relationships in terms of land subsidence were found with groundwater level, active faults, accumulated soft soil thickness and different aquifer types. Furthermore, a relationship with the distances to pumping wells was also recognized in this work.

Monitoring Mining Subsidence Using A Combination of Phase-Stacking and Offset-Tracking Methods

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Hongdong Fan

2015-07-01

Full Text Available An approach to study the mechanism of mining-induced subsidence, using a combination of phase-stacking and sub-pixel offset-tracking methods, is reported. In this method, land subsidence with a small deformation gradient was calculated using time-series differential interferometric synthetic aperture radar (D-InSAR data, whereas areas with greater subsidence were calculated by a sub-pixel offset-tracking method. With this approach, time-series data for mining subsidence were derived in Yulin area using 11 TerraSAR-X (TSX scenes from 13 December 2012 to 2 April 2013. The maximum mining subsidence and velocity values were 4.478 m and 40 mm/day, respectively, which were beyond the monitoring capabilities of D-InSAR and advanced InSAR. The results were compared with the GPS field survey data, and the root mean square errors (RMSE of the results in the strike and dip directions were 0.16 m and 0.11 m, respectively. Four important results were obtained from the time-series subsidence in this mining area: (1 the mining-induced subsidence entered the residual deformation stage within about 44 days; (2 the advance angle of influence changed from 75.6° to 80.7°; (3 the prediction parameters of mining subsidence; (4 three-dimensional deformation. This method could be used to predict the occurrence of mining accidents and to help in the restoration of the ecological environment after mining activities have ended.

Model test on partial expansion in stratified subsidence during foundation pit dewatering

Science.gov (United States)

Wang, Jianxiu; Deng, Yansheng; Ma, Ruiqiang; Liu, Xiaotian; Guo, Qingfeng; Liu, Shaoli; Shao, Yule; Wu, Linbo; Zhou, Jie; Yang, Tianliang; Wang, Hanmei; Huang, Xinlei

2018-02-01

Partial expansion was observed in stratified subsidence during foundation pit dewatering. However, the phenomenon was suspected to be an error because the compression of layers is known to occur when subsidence occurs. A slice of the subsidence cone induced by drawdown was selected as the prototype. Model tests were performed to investigate the phenomenon. The underlying confined aquifer was generated as a movable rigid plate with a hinge at one end. The overlying layers were simulated with remolded materials collected from a construction site. Model tests performed under the conceptual model indicated that partial expansion occurred in stratified settlements under coordination deformation and consolidation conditions. During foundation pit dewatering, rapid drawdown resulted in rapid subsidence in the dewatered confined aquifer. The rapidly subsiding confined aquifer top was the bottom deformation boundary of the overlying layers. Non-coordination deformation was observed at the top and bottom of the subsiding overlying layers. The subsidence of overlying layers was larger at the bottom than at the top. The layers expanded and became thicker. The phenomenon was verified using numerical simulation method based on finite difference method. Compared with numerical simulation results, the boundary effect of the physical tests was obvious in the observation point close to the movable endpoint. The tensile stress of the overlying soil layers induced by the underlying settlement of dewatered confined aquifer contributed to the expansion phenomenon. The partial expansion of overlying soil layers was defined as inversed rebound. The inversed rebound was induced by inversed coordination deformation. Compression was induced by the consolidation in the overlying soil layers because of drainage. Partial expansion occurred when the expansion exceeded the compression. Considering the inversed rebound, traditional layer-wise summation method for calculating subsidence should be

Production induced subsidence and seismicity in the Groningen gas field - can it be managed?

Science.gov (United States)

de Waal, J. A.; Muntendam-Bos, A. G.; Roest, J. P. A.

2015-11-01

much and as fast as realistically possible. Before taking such a decision, the Minister of Economic Affairs requested further studies. The results became available early 2014 and led to the government decision to lower gas production in the earthquake prone central area of the field by 80 % for the next three~years. In addition further investigations and a program to strengthen houses and infrastructure were started. Important lessons have been learned from the studies carried out to date. It is now realised that uncertainties in predicted subsidence and seismicity are much larger than previously recognised. Compaction, subsidence and seismicity are strongly interlinked and relate in a non-linear way to production and pressure drop. The latest studies by the operator suggest that seismic hazard in Groningen is largely determined by tremors with magnitudes between 4.5 and 5.0 even at an annual probability of occurrence of less than 1 %. And that subsidence in 2080 in the centre of the bowl could be anywhere between 50 and 70 cm. Initial evaluations by the regulator indicate similar numbers and suggest that the present seismic risk is comparable to Dutch flooding risks. Different models and parameters can be used to describe the subsidence and seismicity observed so far. The choice of compaction and seismicity models and their parameters has a large impact on the calculated future subsidence (rates), seismic activity and on the predicted response to changes in gas production. In addition there are considerable uncertainties in the ground motions resulting from an earthquake of a given magnitude and in the expected response of buildings and infrastructure. As a result uncertainties in subsidence and seismicity become very large for periods more than three to five years into the future. To counter this a control loop based on interactive modelling, measurements and repeated calibration will be used. Over the coming years, the effect of the production reduction in the

Discussion: some new findings from surface subsidence monitoring over longwall panels

International Nuclear Information System (INIS)

Luo, Y.; Peng, S.S.; Arioglu, E.

1992-01-01

The article consists of a discussion of the paper, 'some new findings from surface subsidence monitoring over longwall panels' and a reply by the paper's authors, Luo and Peng. The reviewer, Arioglu, regards the paper favourably but suggests that surface subsidence can be represented by an exponential expression, and that there is a regression equation linking possible subsidence, pillar loading and the height-to-width ratio of the pillars left. Luo and Peng reply with their reasons for preferring their original linear regression model to the non-linear models suggested by Arioglu. 4 figs

Anthropogenic and geologic influences on subsidence in the vicinity of New Orleans, Louisiana

Science.gov (United States)

Jones, Cathleen E.; An, Karen; Blom, Ronald G.; Kent, Joshua D.; Ivins, Erik R.; Bekaert, David

2016-05-01

New measurements of ongoing subsidence of land proximal to the city of New Orleans, Louisiana, and including areas around the communities of Norco and Lutcher upriver along the Mississippi are reported. The rates of vertical motion are derived from interferometric synthetic aperture radar (InSAR) applied to Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) data acquired on 16 June 2009 and 2 July 2012. The subsidence trends are similar to those reported for 2002-2004 in parts of New Orleans where observations overlap, in particular in Michoud, the 9th Ward, and Chalmette, but are measured at much higher spatial resolution (6 m). The spatial associations of cumulative surface movements suggest that the most likely drivers of subsidence are groundwater withdrawal and surficial drainage/dewatering activities. High subsidence rates are observed localized around some major industrial facilities and can affect nearby flood control infrastructure. Substantial subsidence is observed to occur rapidly from shallow compaction in highly localized areas, which is why it could be missed in subsidence surveys relying on point measurements at limited locations.

Land Subsidence Caused by Groundwater Exploitation in Quetta Valley, Pakistan

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Najeebullah Kakar

2016-12-01

Full Text Available Land subsidence is affecting several metropolitan cities in developing as well as developed countries around the world such as Nagoya (Japan, Shanghai (China, Venice (Italy and San Joaquin valley (United States. This phenomenon is attributed to natural as well as anthropogenic activities that include extensive groundwater withdrawals. Quetta is the largest city of Balochistan province in Pakistan. This valley is mostly dry and ground water is the major source for domestic and agricultural consumption. The unplanned use of ground water resources has led to the deterioration of water quality and quantity in the Quetta valley. Water shortage in the region was further aggravated by the drought during (1998-2004 that hit the area forcing people to migrate from rural to urban areas. Refugees from the war torn neighboring Afghanistan also contributed to rapid increase in population of Quetta valley that has increased from 0.26 million in 1975 to 3.0 million in 2016. The objective of this study was to measure the land subsidence in Quetta valley and identify the effects of groundwater withdrawals on land subsidence. To achieve this goal, data from five Global Positioning System (GPS stations were acquired and processed. Furthermore the groundwater decline data from 41 observation wells during 2010 to 2015 were calculated and compared with the land deformation. The results of this study revealed that the land of Quetta valley is subsiding from 30mm/y on the flanks to 120 mm/y in the central part. 1.5-5.0 m/y of groundwater level drop was recorded in the area where the rate of subsidence is highest. So the extensive groundwater withdrawals in Quetta valley is considered to be the driving force behind land subsidence.

Preventing and controlling land subsidence in Shanghai -towards more integrated and effective land use and ground water governance in the Yangtze Delta

Science.gov (United States)

Dai, Liping

2016-04-01

The Yangtze Delta, covers 210,700 square kilometers and with 156 million inhabitants (NRDC, 2010; The National Bureau of Statistics, 2011), is one of the areas most severely affected by land subsidence in China. Up to 2012, the area with cumulative subsidence above 200 mm in Yangtze Delta has been closed to 10,000 square kilometers. Shanghai, located at the estuary of the Yangtze River and with a population of 23 million, is the most densely populated city in Yangtze Delta (The National Bureau of Statistics, 2011). Since 1921, the recorded cumulative subsidence has been 200 to 300 mm in the central area of the city (Chai, Shen, Zhu, & Zhang, 2005). Excessive pumping of groundwater is considered to be the leading reason, accounts for nearly 70%, of the city's land subsidence, the weight of skyscrapers and global warming also play hefty roles (30%) (Springer, 2012). Research has shown that the main method to control land subsidence in Shanghai is to prevent groundwater from dropping (Chai, Shen, Zhu, & Zhang, 2005), the city has made great efforts in this regard since 1965 (the beginning of the so-called "control period"), for example, it has been recharging underground water through 121 wells with more than 60,000 tons every day since 2012 (Chinadaily, 2012). It is a huge burden considering the city has been suffering from a shortage of fresh water. In 2013, with the other two provinces of Jiangsu and Zhejiang in Yangtze Delta, Shanghai signed a delta cooperation agreement on the prevention and control of land subsidence and jointly issued a Prevention and Control Planning on Land Subsidence in Yangtze Delta (2014-2020), which aims to establish a long-effect mechanism in the delta scope. This research aims to analyze and assess the land and groundwater governance arrangements related to land subsidence in the Yangtze Delta in general and Shanghai in specific, in order to develop optimizing adaptation strategies and associated governance arrangements. It examines the

Leveraging Subsidence in Permafrost with Remotely Sensed Active Layer Thickness (ReSALT) Products

Science.gov (United States)

Schaefer, K. M.; Chen, A.; Chen, J.; Chen, R. H.; Liu, L.; Michaelides, R. J.; Moghaddam, M.; Parsekian, A.; Tabatabaeenejad, A.; Thompson, J. A.; Zebker, H. A.; Meyer, F. J.

2017-12-01

The Remotely Sensed Active Layer Thickness (ReSALT) product uses the Interferometric Synthetic Aperture Radar (InSAR) technique to measure ground subsidence in permafrost regions. Seasonal subsidence results from the expansion of soil water into ice as the surface soil or active layer freezes and thaws each year. Subsidence trends result from large-scale thaw of permafrost and from the melting and subsequent drainage of excess ground ice in permafrost-affected soils. The attached figure shows the 2006-2010 average seasonal subsidence from ReSALT around Barrow, Alaska. The average active layer thickness (the maximum surface thaw depth during summer) is 30-40 cm, resulting in an average seasonal subsidence of 1-3 cm. Analysis of the seasonal subsidence and subsidence trends provides valuable insights into important permafrost processes, such as the freeze/thaw of the active layer, large-scale thawing due to climate change, the impact of fire, and infrastructure vulnerability. ReSALT supports the Arctic-Boreal Vulnerability Experiment (ABoVE) field campaign in Alaska and northwest Canada and is a precursor for a potential NASA-ISRO Synthetic Aperture Radar (NISAR) product. ReSALT includes uncertainties for all parameters and is validated against in situ measurements from the Circumpolar Active Layer Monitoring (CALM) network, Ground Penetrating Radar and mechanical probe measurements. Here we present examples of ReSALT products in Alaska to highlight the untapped potential of the InSAR technique to understand permafrost dynamics, with a strong emphasis on the underlying processes that drive the subsidence.

Consideration on the restoring plan in the subsidence prone areas through the development of ground stability assessment techniques

Energy Technology Data Exchange (ETDEWEB)

Choi, S.O.; Kwon, K.S.; Kim, I.H.; Cho, W.J.; Shin, H.S.; Lee, J.R.; Song, W.K.; Synn, J.H.; Park, C. [Korea Institute of Geology Mining and Materials, Taejon (Korea, Republic of)

1997-12-01

Most of the ground stability analysis on the subsidence prone areas used to be performed through the conventional routine work which consist of a geological survey, a review of the ragged mining map, a trace-investigation on the surface subsidence, a coring job on the prone areas, a rock mass classification, and a two dimensional numerical analysis. Through the above works, we could analyze the stability problems of a surface structure and the tendency of a surface subsidence. However so many problems have been pointed out during the analysis of the subsidence problem owing to the lack of quantitative data in geological survey, the unreliability of the input data for numerical analysis. Also new techniques for ground stability on subsidence area which can replace the conventional passive method are requested among the civil and mining engineers for the safety control of the surface structure including the road and tunnel. In this study, the basic mechanism for the surface subsidence was surveyed first, and the proper input data for the two and three dimensional numerical analysis was selected. And these results were applied to Si-Heung Mine. According to the two dimensional numerical analysis, there is no possibility of surface subsidence even though tension failure was developed up to the region three times to the height of the cavity. Meanwhile the existing data for joints and the ground water was re-evaluated in order to analyze their effects on the subsidence. If we can recognize the characteristics of the spatial data on them in the future, the effect of the joint and ground water on the subsidence can be found out more precisely through the combination with GIS. Finally a finite difference numerical method was applied to Si-Heung Mine in the three dimension. But it was revealed that there are some problems in the three dimensional technique. In other words, it is difficult to obtain the exact spatial coordinates of the cavity, and the researcher should have

Investigation of the Active layer thickness and ground subsidence in Taimyr

Science.gov (United States)

Grebenets, V. I.; Tolmanov, V. A.; Streletskiy, D. A.

2017-12-01

The active layer of permafrost (ALT) is highly unstable and dynamic in space and time. Soil undergoes frost heave during the freezing process, and ground subsidence during the thawing. The problem of the development of soil sediments' deformations in ALT is relevant as for natural objects (influence on runoff, changing of landscape and vegetation, etc.), so for industrial infrastructure (pipelines, roads, buildings and structures). The observations in the frame of the CALM program in Taimyr were carried out since 2005 (site R-32) with the measurements of the geodetic level of soil surface since 2007. The results of these measurements were processed and the maps of thawing and changes in meso- and micro-relief were constructed. The differentiation of seasonally thawed layer and ground subsidence in different micro-landscape conditions was investigated. The depth of seasonal thawing and the changes of surface movements were found to be determined by three main systems: a) the weather conditions and the climate trends; b) the permafrost-lithological conditions and drainage; c) the micro-landscape characteristics. It was established that for the Norilsk region (Taimyr) the trend in increasing ALT was 0.3 cm / year (for the period of observations 2005-2016) with a certain slowdown in the last 3 to 4 years. Increase in the depth of the ALT was related to the rising Summer temperatures and reduction of the cold period. A strong high impact of the summer precipitation conditions was revealed: in rather cold summer of 2012, with large amount of precipitation mainly in the warmest month (July), the defrosting was the highest. In the year with the record-breaking number of positive degree days (from all the 85 years of regular meteorological observations) but anomalously dry year 2013 (in July - less than 10 mm atmospheric precipitation), the thawing was minimal at the R-32 site. It is interesting that the ground subsidence in 2012 was 30-40% less, than in 2013. This is due

Superior coexistence: systematicALLY regulatING land subsidence BASED on set pair theory

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Y. Chen

2015-11-01

Full Text Available Anthropogenic land subsidence is an environmental side effect of exploring and using natural resources in the process of economic development. The key points of the system for controlling land subsidence include cooperation and superior coexistence while the economy develops, exploring and using natural resources, and geological environmental safety. Using the theory and method of set pair analysis (SPA, this article anatomises the factors, effects, and transformation of land subsidence. Based on the principle of superior coexistence, this paper promotes a technical approach to the system for controlling land subsidence, in order to improve the prevention and control of geological hazards.

Assessment of South Pars Gas Field Subsidence Due To Gas Withdrawal

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Akbar Ghazifard

2014-12-01

Full Text Available Withdrawal of oil and gas from reservoirs causes a decrease in pore pressure and an increase in effective stress which results to a reservoir compaction. Reservoir compaction will result in surface subsidence through the elastic response of the subsurface. Usually in order to determine the subsidence above a hydrocarbon field, the reservoir compaction must be first calculated and then the effect of this compaction on the surface should be modeled. The use of the uniaxial compaction theory is more prevalent and an accepted method for determining the amount of reservoir compaction. But despite of the reservoir compaction calculation method, there are many methods with different advantages and shortcomings for modeling of surface subsidence. In this study, a simple analytical method and semi‌-analytical methods (AEsubs software were used for modeling of the surface subsidence of the South Pars gas field at the end of the production period.

Methods for monitoring land subsidence and earth fissures in the Western USA

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K. C. Fergason

2015-11-01

Full Text Available Depletion of groundwater resources in many deep alluvial basin aquifers in the Western USA is causing land subsidence, as it does in many regions worldwide. Land subsidence can severely and adversely impact infrastructure by changing the ground elevation, ground slope (grade and through the development of ground cracks known as earth fissures that can erode into large gullies. Earth fissures have the potential to compromise the foundations of dams, levees, and other infrastructure and cause failure. Subsequent to an evaluation of the overall subsidence experienced in the vicinity of subsidence-impacted infrastructure, a detailed investigation to search for earth fissures, and design and/or mitigation of potentially effected infrastructure, a focused monitoring system should be designed and implemented. Its purpose is to provide data, and ultimately knowledge, to reduce the potential adverse impacts of land subsidence and earth fissure development to the pertinent infrastructure. This risk reduction is realized by quantifying the rate and distribution of ground deformation, and to detect ground rupture if it occurs, in the vicinity of the infrastructure. The authors have successfully designed and implemented monitoring systems capable of quantifying rates and distributions of ground subsidence and detection of ground rupture at multiple locations throughout the Western USA for several types of infrastructure including dams, levees, channels, basins, roadways, and mining facilities. Effective subsidence and earth fissure monitoring requires understanding and quantification of historic subsidence, estimation of potential future subsidence, delineation of the risk for earth fissures that could impact infrastructure, and motivation and resources to continue monitoring through time. A successful monitoring system provides the means to measure ground deformation, grade changes, displacement, and anticipate and assess the potential for earth fissuring

Estimating the Impact of Urban Expansion on Land Subsidence Using Time Series of DMSP Night-Time Light Satellite Imagery

Science.gov (United States)

Jiao, S.; Yu, J.; Wang, Y.; Zhu, L.; Zhou, Q.

2018-04-01

In recent decades, urbanization has resulted a massive increase in the amount of infrastructure especially large buildings in large cities worldwide. There has been a noticeable expansion of entire cities both horizontally and vertically. One of the common consequences of urban expansion is the increase of ground loads, which may trigger land subsidence and can be a potential threat of public safety. Monitoring trends of urban expansion and land subsidence using remote sensing technology is needed to ensure safety along with urban planning and development. The Defense Meteorological Satellite Program Operational Line scan System (DMSP/OLS) Night-Time Light (NTL) images have been used to study urbanization at a regional scale, proving the capability of recognizing urban expansion patterns. In the current study, a normalized illuminated urban area dome volume (IUADV) based on inter-calibrated DMSP/OLS NTL images is shown as a practical approach for estimating urban expansion of Beijing at a single period in time and over subsequent years. To estimate the impact of urban expansion on land subsidence, IUADV was correlated with land subsidence rates obtained using the Stanford Method for Persistent Scatterers (StaMPS) approach within the Persistent Scatterers InSAR (PSInSAR) methodology. Moderate correlations are observed between the urban expansion based on the DMSP/OLS NTL images and land subsidence. The correlation coefficients between the urban expansion of each year and land subsidence tends to gradually decrease over time (Coefficient of determination R = 0.80 - 0.64 from year 2005 to year 2010), while the urban expansion of two sequential years exhibit an opposite trend (R = 0.29 - 0.57 from year 2005 to year 2010) except for the two sequential years between 2007 and 2008 (R = 0.14).

Time-dependent inversion of surface subsidence due to dynamic reservoir compaction

NARCIS (Netherlands)

Muntendam-Bos, A.G.; Kroon, I.C.; Fokker, P.A.

2008-01-01

We introduce a novel, time-dependent inversion scheme for resolving temporal reservoir pressure drop from surface subsidence observations (from leveling or GPS data, InSAR, tiltmeter monitoring) in a single procedure. The theory is able to accommodate both the absence of surface subsidence estimates

How to subsidize energy efficiency under duopoly efficiently?

International Nuclear Information System (INIS)

Nie, Pu-yan; Yang, Yong-cong; Chen, You-hua; Wang, Zhao-hui

2016-01-01

Highlights: • This article captures the effects of output subsidy. • Firms without subsidy are not willing to improve energy efficiency. • Subsidy stimulates the subsidized firms’ outputs and deters the others’ outputs. • The subsidy intensity depends on firms’ position. • Overdue subsidy cannot reach the environmental object. - Abstract: Establishing a game theory model, this paper captures the effects of output subsidy on energy efficiency under Cournot competition and Stackelberg competition. Three types of subsidies are considered in the model, namely without subsidy, unilateral subsidy and bilateral subsidy. The findings indicate that firms without subsidy are not willing to improve energy efficiency. Also, subsidy stimulates the subsidized firms’ outputs while deters the outputs of other firms. Meanwhile, the equilibrium subsidy intensity depends on firms’ position. Furthermore, the minimal subsidy budgets under different situations are presented. Especially, given the fixed subsidy budget, the output of the subsidized firm is the highest if this firm plays the leading position. In addition, certain subsidy can reduce the total emission, while overdue subsidy cannot reach the environmental object.

E-Area LLWF Vadose Zone Model: Probabilistic Model for Estimating Subsided-Area Infiltration Rates

Energy Technology Data Exchange (ETDEWEB)

Dyer, J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Flach, G. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2017-12-12

A probabilistic model employing a Monte Carlo sampling technique was developed in Python to generate statistical distributions of the upslope-intact-area to subsided-area ratio (Area_UAi/Area_SAi) for closure cap subsidence scenarios that differ in assumed percent subsidence and the total number of intact plus subsided compartments. The plan is to use this model as a component in the probabilistic system model for the E-Area Performance Assessment (PA), contributing uncertainty in infiltration estimates.

Consolidation and shear failure leading to subsidence and settlement. Final report

International Nuclear Information System (INIS)

Abeele, W.; Nyhan, J.W.; Hakonson, T.E.; Drennon, B.J.; Lopez, E.A.; Herrera, W.J.; Langhorst, G.J.; Martinez, J.L.; Trujillo, G.

1986-02-01

Subsidence and settlement are phenomena that are much more destructive than generally thought. In shallow land burials they may lead to cracking of the overburden and eventual exposure and escape of waste material. The primary causes are consolidation and cave-ins. Laboratory studies performed at Los Alamos permit us to predict settlement caused by consolidation or natural compaction of the crushed tuff overburden. We have also investigated the shear failure characteristics of crushed tuff that may lead to subsidence. Examples of expected settlement and subsidence are calculated based on the known geotechnical characteristics of crushed tuff. The same thing is done for bentonite/tuff mixes because some field experiments were performed using this additive (bentonite) to reduce the hydraulic conductivity of the crushed tuff. Remedial actions, i.e., means to limit the amount of settlement, are discussed. We finally discuss our field experiment, which studies the influence of subsidence on layered systems in general and on biobarriers in particular. The share of the produced cavities is compared with cavities produced by idealized voids in an idealized environment. Study of root penetration at subsidence sites gives us an indication of the remaining degree of integrity. 30 refs., 24 figs., 19 tabs

Recent ground subsidence at Crown Road, Tauhara and its probable causes

International Nuclear Information System (INIS)

Bromley, Chris J.; Manville, Vern R.; Rosenberg, Michael D.; Currie, Steve

2009-01-01

A localised ground subsidence anomaly at Crown Road, Taupo, within the Tauhara field of the Wairakei-Tauhara geothermal system, has been subjected to intense scrutiny because of its relatively recent onset and proximity to urban areas. Over a period of 20 years a maximum of 0.63 m of subsidence has accumulated. Uncertainties regarding its cause remain, but the evidence now strongly favours a relatively shallow (about 50 m depth) origin, compared with other geothermal subsidence bowls at Wairakei, Tauhara and Ohaaki. Declining water levels in a shallow boiling aquifer are considered to be the principal driving mechanism at Crown Road. The source of the subsidence is an anomalously compressible formation of intensely altered ignimbrite found at the base of a buried hydrothermal eruption deposit. This formation is dominated by soft kaolinite and smectite-illite clays of high plasticity and water content, resulting from alteration of highly vesiculated pumice, and is capped by a thin hardpan of silicified pyroclastic material, characterised by vuggy macro-porosity, at about 33 m depth. During initiation of the subsidence event, this hardpan may have failed in shear mode around the edges of a buried eruption crater, allowing the overburden to fully load the underlying compressible clays. (author)

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

Directory of Open Access Journals (Sweden)

Laijian Wang

2017-10-01

Full Text Available 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 for the artificial wetland was established based on cost–benefit analysis by means of field monitoring, social surveys, GIS geostatistics, raster calculation methods, etc. Empirical analysis and calculations were performed on the case study region. The following conclusions were drawn: (1 after ecological restoration, ecosystem services of Jiuli Lake wetland which has become a national level wetland park yield positive values; (2 the improved environment of the Jiuli Lake wetland has a spillover effect on the price of surrounding land, resulting in land price appreciation; (3 using GIS geostatistics and raster calculation methods, the impact range, strength, and value of the spillover effect can be explicitly measured; (4 through the establishment of a value assessment model of the artificial wetland, incomes of the ecological restoration was found to be sufficient to cover the implementation costs, which provides a research foundation for economic feasibility of ecological restoration of mining subsided lakes.

3D characterization of Holocene peat in the Netherlands : Implications for coastal-deltaic subsidence

NARCIS (Netherlands)

Koster, K.

2017-01-01

Human-induced subsidence threatens many coastal-deltaic plains, due to the amplifying effects it has on sea-level rise and flood risk. In the coastal-deltaic plain of the Netherlands, subsidence is primarily caused by the compression and oxidation of Holocene peat. The understanding of subsidence in

Consolidation and shear failure leading to subsidence and settlement. Part I

International Nuclear Information System (INIS)

Abeele, W.V.

1985-11-01

Subsidence and settlement are phenomena that are much more destructive than generally thought. In shallow land burials they may lead to cracking of the overburden and eventual exposure and escape of waste material. The primary causes are consolidation and cave-ins. Laboratory studies performed at Los Alamos permit us to predict settlement caused by consolidation or natural compaction of the crushed tuff overburden. We have also investigated the shear failure characteristics of crushed tuff that may lead to subsidence. Examples of expected settlement and subsidence are calculated based on the known geotechnical characteristics of crushed tuff. The same thing is done for bontonite/tuff mixes because some field experiments were performed using this additive (bentonite) to reduce the hydraulic conductivity of the crushed tuff. Remedial actions, i.e., means to limit the amount of settlement, are discussed. Finally, we briefly comment on our current field experiment, which studies the influence of subsidence on layered systems in general and on biombarriers in particular

Regional subsidence history and 3D visualization with MATLAB of the Vienna Basin, central Europe

Science.gov (United States)

Lee, E.; Novotny, J.; Wagreich, M.

2013-12-01

This study reconstructed the subsidence history by the backstripping and 3D visualization techniques, to understand tectonic evolution of the Neogene Vienna Basin. The backstripping removes the compaction effect of sediment loading and quantifies the tectonic subsidence. The amount of decompaction was calculated by porosity-depth relationships evaluated from seismic velocity data acquired from two boreholes. About 100 wells have been investigated to quantify the subsidence history of the Vienna Basin. The wells have been sorted into 10 groups; N1-4 in the northern part, C1-4 in the central part and L1-2 in the northernmost and easternmost parts, based on their position within the same block bordered by major faults. To visualize 3D subsidence maps, the wells were arranged to a set of 3D points based on their map location (x, y) and depths (z1, z2, z3 ...). The division of the stratigraphic column and age range was arranged based on the Central Paratethys regional Stages. In this study, MATLAB, a numerical computing environment, was used to calculate the TPS interpolation function. The Thin-Plate Spline (TPS) can be employed to reconstruct a smooth surface from a set of 3D points. The basic physical model of the TPS is based on the bending behavior of a thin metal sheet that is constrained only by a sparse set of fixed points. In the Lower Miocene, 3D subsidence maps show strong evidence that the pre-Neogene basement of the Vienna Basin was subsiding along borders of the Alpine-Carpathian nappes. This subsidence event is represented by a piggy-back basin developed on top of the NW-ward moving thrust sheets. In the late Lower Miocene, Group C and N display a typical subsidence pattern for the pull-apart basin with a very high subsidence event (0.2 - 1.0 km/Ma). After the event, Group N shows remarkably decreasing subsidence, following the thin-skinned extension which was regarded as the extension model of the Vienna Basin in the literature. But the subsidence in

Compaction and subsidence of the Groningen gas field in the Netherlands

NARCIS (Netherlands)

Thienen-Visser, K. van; Pruiksma, J.P.; Breunese, J.N.

2015-01-01

The Groningen gas field in the Netherlands is Europe’s largest gas field. It has been produced since 1963 and production is expected to continue until 2080. The pressure decline in the field causes compaction in the reservoir which is observed as subsidence at the surface. Measured subsidence is

Land subsidence of coastal areas of Jiangsu Province, China: historical review and present situation

Directory of Open Access Journals (Sweden)

J. Q. Zhu

2015-11-01

Full Text Available Surface faults related to land subsidence have been observed in coastal cities, such as Nantong, Yancheng, and Lian Yungang, in Jiangsu Province (CAJS since the early 1970s. Nowadays, increases flooding and rising sea levels are attributed to subsidence caused by groundwater pumping. In this work we present a brief description of land subsidence in CAJS, we examine the mechanisms of land subsidence induced mainly by groundwater pumping and its evolution and economic implications as well as the implemented measures by the local government to prevent new damage.

Land subsidence of coastal areas of Jiangsu Province, China: historical review and present situation

Science.gov (United States)

Zhu, J. Q.; Yang, Y.; Yu, J.; Gong, X. L.

2015-11-01

Surface faults related to land subsidence have been observed in coastal cities, such as Nantong, Yancheng, and Lian Yungang, in Jiangsu Province (CAJS) since the early 1970s. Nowadays, increases flooding and rising sea levels are attributed to subsidence caused by groundwater pumping. In this work we present a brief description of land subsidence in CAJS, we examine the mechanisms of land subsidence induced mainly by groundwater pumping and its evolution and economic implications as well as the implemented measures by the local government to prevent new damage.

A Mixed Prediction Model of Ground Subsidence for Civil Infrastructures on Soft Ground

Directory of Open Access Journals (Sweden)

Kiyoshi Kobayashi

2012-01-01

Full Text Available The estimation of ground subsidence processes is an important subject for the asset management of civil infrastructures on soft ground, such as airport facilities. In the planning and design stage, there exist many uncertainties in geotechnical conditions, and it is impossible to estimate the ground subsidence process by deterministic methods. In this paper, the sets of sample paths designating ground subsidence processes are generated by use of a one-dimensional consolidation model incorporating inhomogeneous ground subsidence. Given the sample paths, the mixed subsidence model is presented to describe the probabilistic structure behind the sample paths. The mixed model can be updated by the Bayesian methods based upon the newly obtained monitoring data. Concretely speaking, in order to estimate the updating models, Markov Chain Monte Calro method, which is the frontier technique in Bayesian statistics, is applied. Through a case study, this paper discussed the applicability of the proposed method and illustrated its possible application and future works.

Production induced subsidence and seismicity in the Groningen gas field – can it be managed?

Directory of Open Access Journals (Sweden)

J. A. de Waal

2015-11-01

production by as much and as fast as realistically possible. Before taking such a decision, the Minister of Economic Affairs requested further studies. The results became available early 2014 and led to the government decision to lower gas production in the earthquake prone central area of the field by 80 % for the next three~years. In addition further investigations and a program to strengthen houses and infrastructure were started. Important lessons have been learned from the studies carried out to date. It is now realised that uncertainties in predicted subsidence and seismicity are much larger than previously recognised. Compaction, subsidence and seismicity are strongly interlinked and relate in a non-linear way to production and pressure drop. The latest studies by the operator suggest that seismic hazard in Groningen is largely determined by tremors with magnitudes between 4.5 and 5.0 even at an annual probability of occurrence of less than 1 %. And that subsidence in 2080 in the centre of the bowl could be anywhere between 50 and 70 cm. Initial evaluations by the regulator indicate similar numbers and suggest that the present seismic risk is comparable to Dutch flooding risks. Different models and parameters can be used to describe the subsidence and seismicity observed so far. The choice of compaction and seismicity models and their parameters has a large impact on the calculated future subsidence (rates, seismic activity and on the predicted response to changes in gas production. In addition there are considerable uncertainties in the ground motions resulting from an earthquake of a given magnitude and in the expected response of buildings and infrastructure. As a result uncertainties in subsidence and seismicity become very large for periods more than three to five years into the future. To counter this a control loop based on interactive modelling, measurements and repeated calibration will be used. Over the coming years, the effect of the production reduction in

Differential subsidence in Mexico City and implications to its Collective Transport System (Metro).

Science.gov (United States)

Solano Rojas, D. E.; Wdowinski, S.; Cabral-Cano, E.; Osmanoglu, B.

2017-12-01

Mexico City is one of the fastest subsiding metropolis in the world. At displacement rates ranging from 0 to -380 [mm/yr], the complex geological setting is subjected to differential subsidence, which has led to damage, operation interruptions, and accidents to the Collective Transport System, or Metro. The Metro plays a critical role in Mexico City, carrying more than four million passengers per day. However, no previous study has focused on the deformation monitoring along the 93 km of the Metro surface railways, mainly because of the limitations of the traditional geodetic techniques. In this study, we use high-resolution Interferometric Synthetic Aperture Radar (InSAR) observations to monitor land subsidence throughout the city and quantify differential subsidence along surface Metro lines. Our analysis is based on 34 TerraSAR-X StripMap scenes acquired from May 2011 to June 2013 and 36 COSMO-SkyMed Stripmap scenes acquired from June 2011 to June 2012. The data were processed using the StaMPS InSAR time series technique, obtaining point densities of up to 4827 points/km2. Our post-processing methodologies include the following two components: (1) Detection of differential subsidence along the metro lines by calculating subsidence gradients, and (2) Detection of apparent uplift—areas subsiding slower than their surroundings—by using spatial frequency filtering. The two analyses allow us to recognize four main consequences of differential subsidence in the Metro system: 1. Deflection in elevated railways, 2. Deflection in street-level railways, 3. Columns with decreased loading capacity, and 4. Apparent uplift affecting surrounding infrastructure. Our results aim at shortening the large gap between scientific geodetic studies and applicable engineering parameters that can be used by local authorities in the city for maintenance and new lines development.

Coal mine subsidence: effects of mitigation on crop yields

International Nuclear Information System (INIS)

Darmody, R.G.; Hetzler, R.T.; Simmons, F.W.

1992-01-01

Subsidence from longwall underground coal mining adversely impacts agricultural land by creating wet or ponded areas. While most subsided areas show little impact, some localized places, usually less than 1.5 ha in size, may experience total crop failure. Coal companies mitigate subsidence damaged cropland by installing drainage waterways or by adding fill material to raise the grade. The objective of this study was to test the effectiveness of mitigation in restoring corn and soybean yields to pre-mined levels. Fourteen sites in southern Illinois were selected for study. Corn (Zea mays L.) and soybean (Glycine max L.) yields from mitigated and nearby undisturbed areas were compared for four years. Results varied due to differing weather and site conditions. Mean corn yields overall, however were significantly (α0.05) lower on mitigated areas. There was no significant difference in overall mean soybean yields. Soil fertility levels were similar and did not account for yield differences. 14 refs., 1 fig., 7 tabs

Integrated geophysical survey in defining subsidence features on a golf course

Science.gov (United States)

Xia, J.; Miller, R.D.

2007-01-01

Subsidence was observed at several places on the Salina Municipal Golf Course in areas known to be built over a landfill in Salina, Kansas. High-resolution magnetic survey (???5400 m2), multi-channel electrical resistivity profiling (three 154 m lines) and microgravity profiling (23 gravity-station values) were performed on a subsidence site (Green 16) to aid in determining boundaries and density deficiency of the landfill in the vicinity of the subsidence. Horizontal boundaries of the landfill were confidently defined by both magnetic anomalies and the pseudo-vertical gradient of total field magnetic anomalies. Furthermore, the pseudo-vertical gradient of magnetic anomalies presented a unique anomaly at Green 16, which provided a criterion for predicting other spots with subsidence potential using the same gradient property. Results of multi-channel electrical resistivity profiling (ERP) suggested the bottom limit of the landfill at Green 16 was around 21 m below the ground surface based on the vertical gradient of electric resistivity and a priori information on the depth of the landfill. ERP results also outlined several possible landfill bodies based on their low resistivity values. Microgravity results suggested a -0.14 g cm-3 density deficiency at Green 16 that could equate to future surface subsidence of as much as 1.5 m due to gradual compaction. ?? 2007 Nanjing Institute of Geophysical Prospecting.

Study on the Rule of Super Strata Movement and Subsidence

Science.gov (United States)

Yao, Shunli; Yuan, Hongyong; Jiang, Fuxing; Chen, Tao; Wu, Peng

2018-01-01

The movement of key strata is related to the safety of the whole earth’s surface for coal mining under super strata. Based on the key strata theory, the paper comprehensively analyzes the characteristics of the subsidence before and after the instability of the super strata by studing through FLAC3D and microseismic dynamic monitoring of the surface rock movement observation. The stability of the super strata movement is analyzed according to the characteristic value of the subsidence. The subsidence law and quantitative indexes under the control of the super rock strata that provides basis for the prevention and control of surface risk, optimize mining area and face layout and reasonably set mining boundary around mining area. It provides basis for the even growth of mine safety production and regional public safety.

Integrating wireless sensor network for monitoring subsidence phenomena

Science.gov (United States)

Marturià, Jordi; Lopez, Ferran; Gigli, Giovanni; Intrieri, Emanuele; Mucchi, Lorenzo; Fornaciai, Alessandro

2016-04-01

An innovative wireless sensor network (WSN) for the 3D superficial monitoring of deformations (such as landslides and subsidence) is being developed in the frame of the Wi-GIM project (Wireless sensor network for Ground Instability Monitoring - LIFE12 ENV/IT/001033). The surface movement is detected acquiring the position (x, y and z) by integrating large bandwidth technology able to detect the 3D coordinates of the sensor with a sub-meter error, with continuous wave radar, which allows decreasing the error down to sub-cm. The Estació neighborhood in Sallent is located over the old potassium mine Enrique. This zone has been affected by a subsidence process over more than twenty years. The implementation of a wide network for ground auscultation has allowed monitoring the process of subsidence since 1997. This network consists of: i) a high-precision topographic leveling network to control the subsidence in surface; ii) a rod extensometers network to monitor subsurface deformation; iii) an automatic Leica TCA Total Station to monitor building movements; iv) an inclinometers network to measure the horizontal displacements on subsurface and v) a piezometer to measure the water level. Those networks were implemented within an alert system for an organized an efficient response of the civil protection authorities in case of an emergency. On 23rd December 2008, an acceleration of subsoil movements (of approx. 12-18 cm/year) provoked the activation of the emergency plan by the Catalan Civil Protection. This implied the preventive and scheduled evacuation of the neighbours (January 2009) located in the area with a higher risk of collapse: around 120 residents of 43 homes. As a consequence, the administration implemented a compensation plan for the evacuation of the whole neighbourhood residents and the demolition of 405 properties. In this work, the adaptation and integration process of Wi-GIM system with those conventional monitoring network are presented for its testing

Catastrophic subsidence: An environmental hazard, shelby county, Alabama

Science.gov (United States)

Lamoreaux, Philip E.; Newton, J. G.

1986-03-01

Induced sinkholes (catastrophic subsidence) are those caused or accelerated by human activities These sinkholes commonly result from a water level decline due to pumpage Construction activities in a cone of depression greatly increases the likelihood of sinkhole occurrence Almost all occur where cavities develop in unconsolidated deposits overlying solution openings in carbonate rocks. Triggering mechanisms resulting from water level declines are (1) loss of buoyant support of the water, (2) increased gradient and water velocity, (3) water-level fluctuations, and (4) induced recharge Construction activities triggering sinkhole development include ditching, removing overburden, drilling, movement of heavy equipment, blasting and the diversion and impoundment of drainage Triggering mechanisms include piping, saturation, and loading Induced sinkholes resulting from human water development/management activities are most predictable in a youthful karst area impacted by groundwater withdrawals Shape, depth, and timing of catastrophic subsidence can be predicted in general terms Remote sensing techniques are used in prediction of locations of catastrophic subsidence. This provides a basis for design and relocation of structures such as a gas pipeline, dam, or building Utilization of techniques and a case history of the relocation of a pipeline are described

Peak shifting and cross-class subsidization: The impacts of solar PV on changes in electricity costs

International Nuclear Information System (INIS)

Johnson, Erik; Beppler, Ross; Blackburn, Chris; Staver, Benjamin; Brown, Marilyn; Matisoff, Daniel

2017-01-01

The expansion of distributed solar necessitates additional research into the impacts on both utilities and their customers. In this paper we use New Jersey solar data, PJM market data, and demand profiles from a PJM utility to investigate rate and bill impacts of large-scale solar penetration. In addition to the subsidization of solar adopters by non-participants, we highlight the channels through which cross-subsidization of rate classes can arise in practice. The results of our study indicate that the fear of a utility “death spiral” may be exaggerated. Significant solar can be incorporated with only a 2% increase in non-participant bills. At high levels of penetration, distributed solar has the potential to alter the system peak hour which affects the allocation of costs across rate-classes. As the peak hour shifts to the evening when solar production diminishes, residential customers face higher distribution costs. Policy makers and utilities need to be aware of these challenges in designing the next generation of rates that are better aligned with cost causality. - Highlights: • We develop a model of electricity costs with large amounts of solar adoption. • Solar adoption leads to cost redistribution across customer classes. • Costs are redistributed partially because peak utility load shifts later in the day. • Residential distributed solar generation affects electricity bills the most. • We confirm the subsidy of participants by non-participants in net metering programs.

Prognosis of surface subsidence affected by underground exploitation of ore vein deposits of Rozna type

Czech Academy of Sciences Publication Activity Database

Hortvík, Karel; Staš, Lubomír

2005-01-01

Roč. 15, č. 1 (2005), s. 296-301 ISSN 1003-6326 R&D Projects: GA ČR GP105/02/P026 Institutional research plan: CEZ:AV0Z3086906 Keywords : mining * subsidence * prognosis Subject RIV: DH - Mining, incl. Coal Mining Impact factor: 0.302, year: 2005

Subsidence Induced Faulting Hazard risk maps in Mexico City and Morelia, central Mexico

Science.gov (United States)

Cabral-Cano, E.; Solano-Rojas, D.; Hernández-Espriu, J.; Cigna, F.; Wdowinski, S.; Osmanoglu, B.; Falorni, G.; Bohane, A.; Colombo, D.

2012-12-01

Subsidence and surface faulting have affected urban areas in Central Mexico for decades and the process has intensified as a consequence of urban sprawl and economic growth. This process causes substantial damages to the urban infrastructure and housing structures and in several cities it is becoming a major factor to be considered when planning urban development, land use zoning and hazard mitigation strategies in the next decades. Subsidence is usually associated with aggressive groundwater extraction rates and a general decrease of aquifer static level that promotes soil consolidation, deformation and ultimately, surface faulting. However, local stratigraphic and structural conditions also play an important role in the development and extension of faults. Despite its potential for damaging housing, and other urban infrastructure, the economic impact of this phenomena is poorly known, in part because detailed, city-wide subsidence induced faulting risk maps have not been published before. Nevertheless, modern remote sensing techniques are most suitable for this task. We present the results of a risk analysis for subsidence induced surface faulting in two cities in central Mexico: Morelia and Mexico City. Our analysis in Mexico City and Morelia is based on a risk matrix using the horizontal subsidence gradient from a Persistent Scatterer InSAR (Morelia) and SqueeSAR (Mexico City) analysis and 2010 census population distribution data from Mexico's National Institute of Statistics and Geography. Defining subsidence induced surface faulting vulnerability within these urbanized areas is best determined using both magnitude and horizontal subsidence gradient. Our Morelia analysis (597,000 inhabitants with localized subsidence rates up to 80 mm/yr) shows that 7% of the urbanized area is under a high to very high risk level, and 14% of its population (11.7% and 2.3% respectively) lives within these areas. In the case of the Mexico City (15'490,000 inhabitants for the

Aerial Photogrammetry observation of the subsidence depression near Karviná

Czech Academy of Sciences Publication Activity Database

Kajzar, Vlastimil; Doležalová, Hana; Souček, Kamil; Staš, Lubomír

2011-01-01

Roč. 8, č. 3 (2011), s. 309-317 ISSN 1214-9705. [Czech-Polish Workshop on Recent Geodynamics of the Sudety Mts. and Adjacent Areas. /11./. Třešť, 04.11.2010-06.11.2010] Grant - others:GA MŠk(CZ) ED2.1.00/03/0082 Institutional research plan: CEZ:AV0Z30860518 Keywords : subsidence depression * monitoring * aerial photogrammetry * GNSS Subject RIV: DH - Mining, incl. Coal Mining Impact factor: 0.530, year: 2011 http://www.irsm.cas.cz/abstracts/AGG/03_11/12_%20Kajzar.pdf

Comparison of allograft and polyetheretherketone (PEEK) cage subsidence rates in anterior cervical discectomy and fusion (ACDF).

Science.gov (United States)

Yson, Sharon C; Sembrano, Jonathan N; Santos, Edward Rainier G

2017-04-01

Structural allografts and PEEK cages are commonly used interbody fusion devices in ACDF. The subsidence rates of these two spacers have not yet been directly compared. The primary aim of this study was to compare the subsidence rate of allograft and PEEK cage in ACDF. The secondary aim was to determine if the presence of subsidence affects the clinical outcome. We reviewed 67 cases (117 levels) of ACDF with either structural allograft or PEEK cages. There were 85 levels (48 cases) with PEEK and 32 levels (19 cases) with allograft spacers. Anterior and posterior disc heights at each operative level were measured at immediate and 6months post-op. Subsidence was defined as a decrease in anterior or posterior disc heights >2mm. NDI of the subsidence (SG) and non-subsidence group (NSG) were recorded. Chi-square test was used to analyze subsidence rates. T-test was used to analyze clinical outcomes (α=0.05). There was no statistically significant difference between subsidence rates of the PEEK (29%; 25/85) and allograft group (28%; 9/32) (p=0.69). Overall mean subsidence was 2.3±1.7mm anteriorly and 2.6±1.2mm posteriorly. Mean NDI improvement was 11.7 (from 47.1 to 35.4; average follow-up: 12mos) for the SG and 14.0 (from 45.8 to 31.8; average follow-up: 13mos) for the NSG (p=0.74). Subsidence rate does not seem to be affected by the use of either PEEK or allograft as spacers in ACDF. Furthermore, subsidence alone does not seem to be predictive of clinical outcomes of ACDF. Copyright © 2017 Elsevier Ltd. All rights reserved.

Subsidence Modeling of the Over-exploited Granular Aquifer System in Aguascalientes, Mexico

Science.gov (United States)

Solano Rojas, D. E.; Pacheco, J.; Wdowinski, S.; Minderhoud, P. S. J.; Cabral-Cano, E.; Albino, F.

2017-12-01

The valley of Aguascalientes in central Mexico experiences subsidence rates of up to 100 [mm/yr] due to overexploitation of its aquifer system, as revealed from satellite-based geodetic observations. The spatial pattern of the subsidence over the valley is inhomogeneous and affected by shallow faulting. The understanding of the subsoil mechanics is still limited. A better understanding of the subsidence process in Aguascalientes is needed to provide insights for future subsidence in the valley. We present here a displacement-constrained finite-element subsidence model, based on the USGS MODFLOW software. The construction of our model relies on 3 main inputs: (1) groundwater level time series obtained from extraction wells' hydrographs, (2) subsurface lithostratigraphy interpreted from well drilling logs, and (3) hydrogeological parameters obtained from field pumping tests. The groundwater level measurements were converted to pore pressure in our model's layers, and used in Terzaghi's equation for calculating effective stress. We then used the effective stress along with the displacement obtained from geodetic observations to constrain and optimize five geo-mechanical parameters: compression ratio, reloading ratio, secondary compression index, over consolidation ratio, and consolidation coefficient. Finally, we use the NEN-Bjerrum linear stress model formulation for settlements to determine elastic and visco-plastic strain, accounting for the aquifer system units' aging effect. Preliminary results show higher compaction response in clay-saturated intervals (i.e. aquitards) of the aquifer system, as reflected in the spatial pattern of the surface deformation. The forecasted subsidence for our proposed scenarios show a much more pronounced deformation when we consider higher groundwater extraction regimes.

Basement tectonics and flexural subsidence along western continental margin of India

Directory of Open Access Journals (Sweden)

D.K. Pandey

2017-09-01

Full Text Available The Paleocene-recent post-rift subsidence history recorded in the Mumbai Offshore Basin off western continental margin of India is examined. Results obtained through 2-D flexural backstripping modelling of new seismic data reveal considerable thermo-tectonic subsidence over last ca. 56 Myr. Reverse post-rift subsidence modelling with variable β stretching factor predicts residual topography of ca. 2000 m to the west of Shelf Margin Basin and fails to restore late Paleocene horizon and the underlying igneous basement to the sea level. This potentially implies that: (1 either the igneous basement formed during the late Cretaceous was emplaced under open marine environs; or (2 a laterally varying cumulative subsidence occurred within Mumbai Offshore Basin (MOB during ca. 68 to ca. 56 Ma. Pre-depositional topographic variations at ca. 56 Ma across the basin could be attributed to the extensional processes such as varied lower crustal underplating along Western Continental Margin of India (WCMI. Investigations about basement tectonics after unroofing of sediments since late Paleocene from this region support a transitional and heavily stretched nature of crust with high to very high β factors. Computations of past sediment accumulation rates show that the basin sedimentation peaked during late Miocene concurrently with uplift of Himalayan–Tibetan Plateau and intensification of Indian monsoon system. Results from basin subsidence modelling presented here may have significant implications for further studies attempting to explore tectono–climatic interactions in Asia.

Land subsidence in the southwestern Mojave Desert, California, 1992–2009

Science.gov (United States)

Brandt, Justin; Sneed, Michelle

2017-07-19

Groundwater has been the primary source of domestic, agricultural, and municipal water supplies in the southwestern Mojave Desert, California, since the early 1900s. Increased demands on water supplies have caused groundwater-level declines of more than 100 feet (ft) in some areas of this desert between the 1950s and the 1990s (Stamos and others, 2001; Sneed and others, 2003). These water-level declines have caused the aquifer system to compact, resulting in land subsidence. Differential land subsidence (subsidence occurring at different rates across the landscape) can alter surface drainage routes and damage surface and subsurface infrastructure. For example, fissuring across State Route 247 at Lucerne Lake has required repairs as has pipeline infrastructure near Troy Lake.Land subsidence within the Mojave River and Morongo Groundwater Basins of the southwestern Mojave Desert has been evaluated using InSAR, ground-based measurements, geology, and analyses of water levels between 1992 and 2009 (years in which InSAR data were collected). The results of the analyses were published in three USGS reports— Sneed and others (2003), Stamos and others (2007), and Solt and Sneed (2014). Results from the latter two reports were integrated with results from other USGS/ MWA cooperative groundwater studies into the broader scoped USGS Mojave Groundwater Resources Web site (http://ca.water.usgs.gov/ mojave/). This fact sheet combines the detailed analyses from the three subsidence reports, distills them into a longer-term context, and provides an assessment of options for future monitoring.

Review of corrective measures to stabilize subsidence in shallow-land burial trenches

International Nuclear Information System (INIS)

Roop, R.D.; Staub, W.P.; Hunsaker, D.B. Jr.; Ketelle, R.H.; Lee, D.W.; Pin, F.G.; Witten, A.J.

1983-05-01

Shallow-land burial of low-level radioactive wastes is frequently followed by subsidence: the slumping, cave-in, or depression of the trench's surface. This report describes and evaluates the measures proposed for correcting subsidence, including roller compaction, grouting, explosives, surcharging, falling mass, pile driving, in situ incineration, and accelerated decomposition. Subsidence, which has occurred at all the major waste disposal sites, has two major causes: filling of packing voids (spaces between waste containers) and filling of interior voids (spaces within containers). Four additional mechanisms also contribute to subsidence: collapse of trench walls, chemical and biological degradation, soil consolidation, and shrink and swell phenomena. Corrective measures for subsidence are evaluated on three criteria: effectiveness, applicability, and cost. The evaluation indicates that one method, falling mass, is considered to be effective, widely applicable, and relatively low in cost, suggesting that this would be the most generally useful technique and would yield the greatest payoff from further development and field trials. There are many uncertainties associated with the cost and effectiveness of corrective measures which can best be resolved by experimental field demonstrations. Site-specific analyses for each disposal area are recommended, to determine which techniques are appropriate and to evaluate the overall desirability of applying corrective measures

Determination of extent of the subsiding areas in the Czech part of Upper Silesian Basin

Czech Academy of Sciences Publication Activity Database

Kadlečík, Pavel; Kajzar, Vlastimil; Marek, Tomáš

-, Part 2 (2012), s. 715-721 ISSN 1314-2704. [International Multidisciplinary Scientific GeoConference & EXPO SGEM 2012 /12./. Albena, 17.06.2012-23.06.2012] Institutional research plan: CEZ:AV0Z30460519; CEZ:AV0Z30860518 Keywords : Upper Silesian Basin * mining * subsidence Subject RIV: DE - Earth Magnetism, Geodesy, Geography

Ring-fault activity at subsiding calderas studied from analogue experiments and numerical modeling

Science.gov (United States)

Liu, Y. K.; Ruch, J.; Vasyura-Bathke, H.; Jonsson, S.

2017-12-01

Several subsiding calderas, such as the ones in the Galápagos archipelago and the Axial seamount in the Pacific Ocean have shown a complex but similar ground deformation pattern, composed of a broad deflation signal affecting the entire volcanic edifice and of a localized subsidence signal focused within the caldera. However, it is still debated how deep processes at subsiding calderas, including magmatic pressure changes, source locations and ring-faulting, relate to this observed surface deformation pattern. We combine analogue sandbox experiments with numerical modeling to study processes involved from initial subsidence to later collapse of calderas. The sandbox apparatus is composed of a motor driven subsiding half-piston connected to the bottom of a glass box. During the experiments the observation is done by five digital cameras photographing from various perspectives. We use Photoscan, a photogrammetry software and PIVLab, a time-resolved digital image correlation tool, to retrieve time-series of digital elevation models and velocity fields from acquired photographs. This setup allows tracking the processes acting both at depth and at the surface, and to assess their relative importance as the subsidence evolves to a collapse. We also use the Boundary Element Method to build a numerical model of the experiment setup, which comprises contracting sill-like source in interaction with a ring-fault in elastic half-space. We then compare our results from these two approaches with the examples observed in nature. Our preliminary experimental and numerical results show that at the initial stage of magmatic withdrawal, when the ring-fault is not yet well formed, broad and smooth deflation dominates at the surface. As the withdrawal increases, narrower subsidence bowl develops accompanied by the upward propagation of the ring-faulting. This indicates that the broad deflation, affecting the entire volcano edifice, is primarily driven by the contraction of the

Cretaceous to Recent Asymetrical Subsidence of South American and West African Conjugate Margins

Science.gov (United States)

Kenning, J.; Mann, P.

2017-12-01

Two divergent interpretations have been proposed for South American rifted-passive margins: the "mirror hypothesis" proposes that the rifted margins form symmetrically from pure shear of the lithosphere while upper-plate-lower plate models propose that the rifted margins form asymmetrically by simple shear. Models based on seismic reflection and refraction imaging and comparison of conjugate, rifted margins generally invoke a hybrid stretching process involving elements of both end member processes along with the effects of mantle plumes active during the rift and passive margin phases. We use subsidence histories of 14, 1-7 km-deep exploration wells located on South American and West African conjugate pairs now separated by the South Atlantic Ocean, applying long-term subsidence to reveal the symmetry or asymmetry of the underlying, conjugate, rift processes. Conjugate pairs characterize the rifted margin over a distance of 3500 km and include: Colorado-South Orange, Punta Del Este-North Orange, South Pelotas-Lüderitz and the North Pelotas-Walvis Basins. Of the four conjugate pairs, more rapid subsidence on the South American plate is consistently observed with greater initial rift and syn-rift subsidence rates of >60m/Ma (compared to 100 m/Ma are observed offshore South Africa between approximately 120-80 Ma, compatible with onset of the post-rift thermal sag phase. During this period the majority of burial is completed and rates remain low at Argentina/Uruguay displays more gradual subsidence throughout the Cretaceous, consistently averaging a moderate 15-30m/Ma. By the end of this stage there is a subsequent increase to 25-60 m/Ma within the last 20 Ma, interpreted to reflect lithospheric loading due to increased sedimentation rates during the Cenozoic. This increase in subsidence rate is not seen in the African conjugate section where the majority of sediments bypassed the highly aggraded Cretaceous shelf. Initially greater on the Brazilian margin compared to

Differential subsidence and its effect on subsurface infrastructure: predicting probability of pipeline failure (STOOP project)

Science.gov (United States)

de Bruijn, Renée; Dabekaussen, Willem; Hijma, Marc; Wiersma, Ane; Abspoel-Bukman, Linda; Boeije, Remco; Courage, Wim; van der Geest, Johan; Hamburg, Marc; Harmsma, Edwin; Helmholt, Kristian; van den Heuvel, Frank; Kruse, Henk; Langius, Erik; Lazovik, Elena

2017-04-01

Due to heterogeneity of the subsurface in the delta environment of the Netherlands, differential subsidence over short distances results in tension and subsequent wear of subsurface infrastructure, such as water and gas pipelines. Due to uncertainties in the build-up of the subsurface, however, it is unknown where this problem is the most prominent. This is a problem for asset managers deciding when a pipeline needs replacement: damaged pipelines endanger security of supply and pose a significant threat to safety, yet premature replacement raises needless expenses. In both cases, costs - financial or other - are high. Therefore, an interdisciplinary research team of geotechnicians, geologists and Big Data engineers from research institutes TNO, Deltares and SkyGeo developed a stochastic model to predict differential subsidence and the probability of consequent pipeline failure on a (sub-)street level. In this project pipeline data from company databases is combined with a stochastic geological model and information on (historical) groundwater levels and overburden material. Probability of pipeline failure is modelled by a coupling with a subsidence model and two separate models on pipeline behaviour under stress, using a probabilistic approach. The total length of pipelines (approx. 200.000 km operational in the Netherlands) and the complexity of the model chain that is needed to calculate a chance of failure, results in large computational challenges, as it requires massive evaluation of possible scenarios to reach the required level of confidence. To cope with this, a scalable computational infrastructure has been developed, composing a model workflow in which components have a heterogeneous technological basis. Three pilot areas covering an urban, a rural and a mixed environment, characterised by different groundwater-management strategies and different overburden histories, are used to evaluate the differences in subsidence and uncertainties that come with

Subsidence monitoring with geotechnical instruments in the Mexicali Valley, Baja California, Mexico

Science.gov (United States)

Glowacka, E.; Sarychikhina, O.; Márquez Ramírez, V. H.; Robles, B.; Nava, F. A.; Farfán, F.; García Arthur, M. A.

2015-11-01

The Mexicali Valley (northwestern Mexico), situated in the southern part of the San Andreas fault system, is an area with high tectonic deformation, recent volcanism, and active seismicity. Since 1973, fluid extraction, from the 1500-3000 m depth range, at the Cerro Prieto Geothermal Field (CPGF), has influenced deformation in the Mexicali Valley area, accelerating the subsidence and causing slip along the traces of tectonic faults that limit the subsidence area. Detailed field mapping done since 1989 (González et al., 1998; Glowacka et al., 2005; Suárez-Vidal et al., 2008) in the vicinity of the CPGF shows that many subsidence induced fractures, fissures, collapse features, small grabens, and fresh scarps are related to the known tectonic faults. Subsidence and fault rupture are causing damage to infrastructure, such as roads, railroad tracks, irrigation channels, and agricultural fields. Since 1996, geotechnical instruments installed by CICESE (Centro de Investigación Ciéntifica y de Educación Superior de Ensenada, B.C.) have operated in the Mexicali Valley, for continuous recording of deformation phenomena. Instruments are installed over or very close to the affected faults. To date, the network includes four crackmeters and eight tiltmeters; all instruments have sampling intervals in the 1 to 20 min range. Instrumental records typically show continuous creep, episodic slip events related mainly to the subsidence process, and coseismic slip discontinuities (Glowacka et al., 1999, 2005, 2010; Sarychikhina et al., 2015). The area has also been monitored by levelling surveys every few years and, since the 1990's by studies based on DInSAR data (Carnec and Fabriol, 1999; Hansen, 2001; Sarychikhina et al., 2011). In this work we use data from levelling, DInSAR, and geotechnical instruments records to compare the subsidence caused by anthropogenic activity and/or seismicity with slip recorded by geotechnical instruments, in an attempt to obtain more information

Subsidence monitoring with geotechnical instruments in the Mexicali Valley, Baja California, Mexico

Directory of Open Access Journals (Sweden)

E. Glowacka

2015-11-01

Full Text Available The Mexicali Valley (northwestern Mexico, situated in the southern part of the San Andreas fault system, is an area with high tectonic deformation, recent volcanism, and active seismicity. Since 1973, fluid extraction, from the 1500–3000 m depth range, at the Cerro Prieto Geothermal Field (CPGF, has influenced deformation in the Mexicali Valley area, accelerating the subsidence and causing slip along the traces of tectonic faults that limit the subsidence area. Detailed field mapping done since 1989 (González et al., 1998; Glowacka et al., 2005; Suárez-Vidal et al., 2008 in the vicinity of the CPGF shows that many subsidence induced fractures, fissures, collapse features, small grabens, and fresh scarps are related to the known tectonic faults. Subsidence and fault rupture are causing damage to infrastructure, such as roads, railroad tracks, irrigation channels, and agricultural fields. Since 1996, geotechnical instruments installed by CICESE (Centro de Investigación Ciéntifica y de Educación Superior de Ensenada, B.C. have operated in the Mexicali Valley, for continuous recording of deformation phenomena. Instruments are installed over or very close to the affected faults. To date, the network includes four crackmeters and eight tiltmeters; all instruments have sampling intervals in the 1 to 20 min range. Instrumental records typically show continuous creep, episodic slip events related mainly to the subsidence process, and coseismic slip discontinuities (Glowacka et al., 1999, 2005, 2010; Sarychikhina et al., 2015. The area has also been monitored by levelling surveys every few years and, since the 1990's by studies based on DInSAR data (Carnec and Fabriol, 1999; Hansen, 2001; Sarychikhina et al., 2011. In this work we use data from levelling, DInSAR, and geotechnical instruments records to compare the subsidence caused by anthropogenic activity and/or seismicity with slip recorded by geotechnical instruments, in an attempt to obtain

Subsidence of the pit slab at SLC experimental hall

International Nuclear Information System (INIS)

Inaba, J.; Himeno, Yoichi; Katsura, Yutaka

1992-01-01

Detectors installed at particle accelerator facilities are quite heavy, weighing thousands of tons. On the other hand, ground subsidence caused by the installation of a detector adversely affects the beam line alignment of the collider. It becomes, therefore, very important to figure out the expected amount of ground settlement by means of adequate evaluation methods in advance. At Stanford Linear Accelerator Center (SLAC), a 1700 mT (metric tons) Mark II detector was replaced with a 4000 mT SLD detector in Stanford Linear Collider (SLC). The exchange started in December 1990 and lasted until March 1991, and the amount of ground settlement was measured by SLAC during that period. We performed simulation studies to evaluate the subsidence of the pit slab using several analysis methods. Parameters used for the analyses were decided based on the information of the SLC structure and the ground conditions at the SLAC area. The objective of this study is to verify the applicability of several simulation methods by comparing the analytical results with the actual subsidence data obtained by SLAC

Modeling of flexible reciprocating compressor considering the crosshead subsidence

Science.gov (United States)

Xue, Xiaogang; Liu, Shulin; Sun, Xin

2018-01-01

Crank-slider mechanisms are important parts of heavy duty machines, including reciprocating compressors, combustion motors. This paper targets on the dynamic response of the crosshead in a reciprocating compressor, taking into consideration the crosshead deviation from the original level. The traditional model of the compressor is usually a slider-mechanism system without considering the deflection of the crosshead, thus neglecting the influence of the piston rod, which has some flexible features. In this paper, a rigid-flexible model of slider-crank is described theoretically, using the commercial software MATLAB, where the crank, connecting rod and crosshead are treated as rigid bodies, while the piston rod connected to the crosshead is considered as a flexible body. The dynamic response of the mechanism with the crosshead subsidence is discussed detailedly in this paper. After calculated theoretically, the MATLAB simulation showed that the dynamic response of the crosshead will be greatly influenced if the crosshead subsided from the original level. Also, the influence of the crosshead subsidence was also investigated, and some extra vibration of the crosshead arises.

Sources of subsidence at the Salton Sea Geothermal Field

Science.gov (United States)

Barbour, Andrew J.; Evans, Eileen; Hickman, Stephen H.; Eneva, Mariana

2016-01-01

At the Salton Sea Geothermal Field (SSGF) in Southern California, surface deformation associated with geologic processes including sediment compaction, tectonic strain, and fault slip may be augmented by energy production activities. Separating the relative contributions from natural and anthropogenic sources is especially important at the SSGF, which sits at the apex of a complex tectonic transition zone connecting the southern San Andreas Fault with the Imperial Fault; but this has been a challenging task so far. Here we analyze vertical surface velocities obtained from the persistent scatterer InSAR method and find that two of the largest subsidence anomalies can be represented by a set of volumetric strain nuclei at depths comparable to geothermal well completion zones. In contrast, the rates needed to achieve an adequate fit to the magnitudes of subsidence are almost an order of magnitude greater than rates reported for annual changes in aggregate net-production volume, suggesting that the physical mechanism responsible for subsidence at the SSGF is a complicated interplay between natural and anthropogenic sources.

Alternatives to control subsidence at low-level radioactive waste burial sites

International Nuclear Information System (INIS)

Phillips, S.J.; Carlson, R.A.

1981-09-01

A substantial quantity of low-level radioactive and hazardous wastes has been interred in shallow land burial structures throughout the United States. Many of these structures (trenches, pits, and landfills) have experienced geotechnical subsidence problems and may require stabilization. Ground surface manifestations of subsidence include: large cracks, basins, and cave-ins. Subsidence is primarily caused by void filling, and physicochemical degradation and solubilization of buried wastes. These surface features represent a potential for increased contamination transport to the biosphere via water, air, biologic, and direct pathways. Engineering alternatives for the reduction of buried waste and matrix materials voids are identified and discussed. The advantages, disadvantages, and costs of each alternative are evaluated. Falling mass, pile driving and in situ incineration engineering alternatives were selected for further development

Mine subsidence event at Washington West Apartments

International Nuclear Information System (INIS)

Wilson, D.B.; Weber, M.W.; Purdy, J.; Acker, P.

1994-01-01

A major mine subsidence event occurred in Scranton, PA in early 1993. The initial damage included breakage of gas and water lines, cracking of pavements and sidewalks, and architectural damage to the seven-story apartment building that houses about 150 elderly persons. Visible damage include a 3/4-in dilation of the expansion joint separating the building, approximately 200 interior and exterior cracks, and distress to utility lines. The Office of Surface mining Reclamation and Enforcement (OSM) funded an integrated geotechnical and structural engineering investigation to determine the cause of the subsidence, the limits of affected areas, and the nature of damage to the building. Work included interior surveys, exterior surveys, installation of crack gages, eight subsurface borings, review of building design drawings, review of geologic and mining data, and structural analysis of the rigid steel frame building. The surveys showed the building had undergone movements consisting of a lateral translation, a longitudinal differential settlement, and a transverse differential settlement. Preliminary structural analyses showed that the differential settlements had introduced significant additional stresses in some of the building columns. This paper provides a case history of the cause and effects of the subsidence event. The techniques used to collect and analyze the data are presented along with the findings of the geotechnical and structural engineering investigations. The paper also describes emergency actions that were implemented, the remedial alternatives that were considered, and the method selected as the recommended alternative

Subsidence and settlement and their effect on shallow land burial

International Nuclear Information System (INIS)

Abeele, W.V.

1985-01-01

Subsidence and settlement are phenomena that are much more destructive than generally thought. In shallow land burials they may lead to cracking of the overburden and eventual exposure and escape of waste material. The primary causes are consolidation and cave-ins. Laboratory studies performed at Los Alamos permit us to predict settlement caused by consolidation or natural compaction of the crushed tuff overburden. Examples of expected settlement and subsidence are calculated based on the known geotechnical characteristics of crushed tuff. The same thing is done for bentonite/tuff mixes because some field experiments were performed using this additive (bentonite) to reduce the hydraulic conductivity of the crushed tuff. Remedial actions, i.e., means to limit the amount of settlement, are discussed. Finally, we briefly comment on our current field experiment, which studies the influence of subsidence on layered systems in general and on biobarriers in particular

Geotechnical and Geological Aspects of Differential Subsidence in the Skaw Spit, Denmark

DEFF Research Database (Denmark)

Andersen, Holger Lykke; Thorsen, Grete; Hauerbach, P.

1996-01-01

Local differential subsidence has been observed by means of repeated precise levellings in the township of Skagen at the northernmost tip of the Skaw Spit in Jutland. We have l studied the possible causes of the subsidence. Oedometer tests have been carried out on undisturbed clayey samples from...

Subsidence characterization and modeling for engineered facilities in Arizona, USA

Directory of Open Access Journals (Sweden)

M. L. Rucker

2015-11-01

Full Text Available Several engineered facilities located on deep alluvial basins in southern Arizona, including flood retention structures (FRS and a coal ash disposal facility, have been impacted by up to as much as 1.8 m of differential land subsidence and associated earth fissuring. Compressible basin alluvium depths are as deep as about 300 m, and historic groundwater level declines due to pumping range from 60 to more than 100 m at these facilities. Addressing earth fissure-inducing ground strain has required alluvium modulus characterization to support finite element modeling. The authors have developed Percolation Theory-based methodologies to use effective stress and generalized geo-material types to estimate alluvium modulus as a function of alluvium lithology, depth and groundwater level. Alluvial material modulus behavior may be characterized as high modulus gravel-dominated, low modulus sand-dominated, or very low modulus fines-dominated (silts and clays alluvium. Applied at specific aquifer stress points, such as significant pumping wells, this parameter characterization and quantification facilitates subsidence magnitude modeling at its' sources. Modeled subsidence is then propagated over time across the basin from the source(s using a time delay exponential decay function similar to the soil mechanics consolidation coefficient, only applied laterally. This approach has expanded subsidence modeling capabilities on scales of engineered facilities of less than 2 to more than 15 km.

Coastal Flooding Hazards due to storm surges and subsidence

DEFF Research Database (Denmark)

Sørensen, Carlo; Knudsen, Per; Andersen, Ole B.

Flooding hazard and risk mapping are major topics in low-lying coastal areas before even considering the adverse effects of sea level rise (SLR) due to climate change. While permanent inundation may be a prevalent issue, more often floods related to extreme events (storm surges) have the largest...... damage potential.Challenges are amplified in some areas due to subsidence from natural and/or anthropogenic causes. Subsidence of even a few mm/y may over time greatly impair the safety against flooding of coastal communities and must be accounted for in order to accomplish the economically most viable...

GIS-based Analysis of LS Factor under Coal Mining Subsidence Impacts in Sandy Region

Directory of Open Access Journals (Sweden)

W. Xiao

2014-09-01

Full Text Available Coal deposits in the adjacent regions of Shanxi, Shaanxi, and Inner Mongolia province (SSI account for approximately two-thirds of coal in China; therefore, the SSI region has become the frontier of coal mining and its westward movement. Numerous adverse impacts to land and environment have arisen in these sandy, arid, and ecologically fragile areas. Underground coal mining activities cause land to subside and subsequent soil erosion, with slope length and slope steepness (LS as the key influential factor. In this investigation, an SSI mining site was chosen as a case study area, and 1 the pre-mining LS factor was obtained using a digital elevation model (DEM dataset; 2 a mining subsidence prediction was implemented with revised subsidence prediction factors; and 3 the post-mining LS factor was calculated by integrating the pre-mining DEM dataset and coal mining subsidence prediction data. The results revealed that the LS factor leads to some changes in the bottom of subsidence basin and considerable alterations at the basin’s edges of basin. Moreover, the LS factor became larger in the steeper terrain under subsidence impacts. This integrated method could quantitatively analyse LS changes and spatial distribution under mining impacts, which will benefit and provide references for soil erosion evaluations in this region

Tectonic subsidence analyses of miogeoclinal strata from mesozoic marginal basin of Peru

Energy Technology Data Exchange (ETDEWEB)

Devlin, W.J.

1988-01-01

The Western Peruvian trough is composed of an eastern miogeoclinical facies of carbonate and clastic strata, and a western eugeoclinal facies consisting of a succession of volcanic and sedimentary rocks. In norther and central Peru, the miogeocline is located between a tectonic hinge adjacent to platformal facies of the Maranon geanticline on the east, and an outer marginal high bounded by the Cordillera Blanca fault and Tapacocha axis on the west. Miogeoclinal and platformal strata in southern Peru occur in a broad belt between Arequipa and Lago Titicaca. A marginal basin setting has been proposed for the Western Peruvian trough and the several kilometers of subsidence in the basin has been attributed to back-arc extension and crustal thinning. As a test of this model, quantitative tectonic subsidence curves were constructed from representative sections within miogeoclinar strata from four localities. Preliminary results indicate that the calculated curves have the same overall form as the age-depth curve for ocean floor, suggesting that subsidence was controlled by cooling and thermal contraction of heated lithosphere. The slopes of the curves are less than those for subsidence of oceanic lithosphere. However, they are in agreement with geologic evidence that the miogeocline accumulated on continental crust. Significant variations in the timing of onset, duration, and magnitude of subsidence are observed between sections from northern and southern Peru.

Piping research program plan

International Nuclear Information System (INIS)

1988-09-01

This document presents the piping research program plan for the Structural and Seismic Engineering Branch and the Materials Engineering Branch of the Division of Engineering, Office of Nuclear Regulatory Research. The plan describes the research to be performed in the areas of piping design criteria, environmentally assisted cracking, pipe fracture, and leak detection and leak rate estimation. The piping research program addresses the regulatory issues regarding piping design and piping integrity facing the NRC today and in the foreseeable future. The plan discusses the regulatory issues and needs for the research, the objectives, key aspects, and schedule for each research project, or group of projects focussing of a specific topic, and, finally, the integration of the research areas into the regulatory process is described. The plan presents a snap-shot of the piping research program as it exists today. However, the program plan will change as the regulatory issues and needs change. Consequently, this document will be revised on a bi-annual basis to reflect the changes in the piping research program. (author)

Establishment of a Subsidence Superstation in the Mississippi Delta: Integrating sediment core, SET, GPS and vertical strainmeter data to understand subsidence

Science.gov (United States)

Steckler, M. S.; Allison, M. A.; Bridgeman, J.; Dixon, T. H.; Hatfield, W.; A Karegar, M.; Tornqvist, T. E.; Zumberge, M. A.; Wyatt, F. K.

2017-12-01

There is a great need for coordinated efforts to monitor and better understand subsidence rates in low-elevation coastal zones by integrating different, complementary techniques at carefully selected sites. We present recent efforts to establish a subsidence superstation in the Mississippi Delta. The site is 2 km from the river near Myrtle Grove, Louisiana, at a CRMS (Coastwide Reference Monitoring System) site. The CRMS site consists of a surface elevation table (SET) and marker horizon established in 2008. The surface elevation relative to a rod driven to refusal (26 m) and the sedimentation above the marker horizon is measured semiannually. Adjacent to this site we have added three borehole optical fiber strainmeters that have been providing continuous records of displacement between the near-surface and depths of 10, 26, and 42 m. The instruments provide unprecedented resolution for compaction studies (see Hatfield et al. abstract). We regularly record teleseismic events with amplitudes <1 μm. The records also show a number of days-long compaction and rebound events of less than 1 mm, resulting from changes in the weather and water level. We have attached GPS to each of the wells. For the deepest well, the GPS is anchored to the bottom of the well with the base of the optical strainmeter. For the other two wells, the GPS is anchored to the upper casing of the well. While drilling the wells, a 5" diameter continuous core was collected reaching the Pleistocene boundary at 37 m depth (see Bridgeman et al. abstract). The silty uppermost 10 m, comprised of proximal overbank deposits, reveal up to 5-6 m of subsidence over the past 3000 years. In contrast, the surficial sediments ( 70 cm) are almost entirely organic matter and show little subsidence. The SET shows only 0.4 mm/yr for a 7.4 yr time window. Over the first year, the strainmeters show no long-term compaction or extension greater than ± 0.5 mm. Precise processing of the available GPS data indicates the

Reduction of surface subsidence risk by fly ash exploitation as filling material in deep mining areas

Czech Academy of Sciences Publication Activity Database

Trčková, Jiřina; Šperl, Jan

2010-01-01

Roč. 53, č. 2 (2010), s. 251-258 ISSN 0921-030X Institutional research plan: CEZ:AV0Z30460519 Keywords : undermining * subsidence of the surface * impact reduction Subject RIV: DO - Wilderness Conservation Impact factor: 1.398, year: 2010 www.springerlink.com/content/y8257893528lp56w/

Subsidence and settlement and their effect on shallow land burial

International Nuclear Information System (INIS)

Abeele, W.V.

1985-01-01

Subsidence and settlement are phenomena that are much more destructive than generally thought. In shallow land burials they may lead to cracking of the overburden and eventual exposure and escape of waste material. The primary causes are consolidation and cave-ins. Laboratory studies performed at Los Alamos permit us to predict settlement caused by consolidation or natural compaction of the crushed tuff overburden. Examples of expected settlement and subsidence are calculated based on the known geotechnical characteristics of crushed tuff. The same thing is done for bentonite/tuff mixes because some field experiments were performed using this additive (bentonite) to reduce the hydraulic conductivity of the crushed tuff. Remedial actions, i.e., means to limit the amount of settlement, are discussed. Finally, we briefly comment on our current field experiment, which studies the influence of subsidence on layered systems, in general, and on biobarriers, in particular. 16 references, 7 figures, 5 tables

Late 20th Century Deep-seated Vertical Motions in New Orleans and implications for Gulf Coast Subsidence

Science.gov (United States)

Dokka, R. K.

2010-12-01

Subsidence of the Mississippi River delta and adjoining coastal areas is widely thought to be dominated by compaction of Holocene sediments. Current public policies regarding hurricane protection and ecosystems restoration are founded on this interpretation. To test this hypothesis, monuments that penetrate the entire Holocene section were measured using geodetic leveling and water gauges attached to bridge foundations. Results show that the entire sampling area subsided between 1955 and 1995 in amounts unanticipated by previous models. Subsidence due to processes originating below the Holocene section locally exceeded 0.9 m between 1955 and 1995. The maxima of deep subsidence occurred in the urbanized and industrialized sections of eastern New Orleans. Subsidence decreased away from urbanized areas and north of the belt of active basin margin normal faults; this decrease in subsidence continued to the north and east along the Mississippi coast. These independent measurements provide insights into the complexity and causes of modern landscape change in the region. Modern subsidence is clearly not dominated solely by shallow processes such as natural compaction, Deep subsidence occurring east and north of the basin margin faults can be explained by regional tectonic loading of the lithosphere by the modern Mississippi River delta and local groundwater withdrawal. Sharp, local changes in subsidence coincide with strands of the basin margin normal fault system. Deep subsidence of the New Orleans area can be explained by a combination of groundwater withdrawal from shallow upper Pleistocene aquifers, the aforementioned lithospheric loading, and non-groundwater-related faulting. Subsidence due to groundwater extraction from aquifers ~160 to 200 m deep dominated the urbanized areas from ~1960 to the early 1990s and is likely responsible for lowering flood protection structures and bridges in the area by as much as ~0.8 m.

Energy research program 82

International Nuclear Information System (INIS)

1982-01-01

The energy research program 82 (EFP-82) is prepared by the Danish ministry of energy in order to continue the extension of the Danish energy research and development started through the former trade ministry's programs EM-1 (1976) and EM-2 (1978), and the energy ministry's programs EFP-80 and EFP-81. The new program is a continuation of the activities in the period 1982-84 with a total budget of 100 mio.Dkr. The program gives a brief description of background, principles, organization and financing, and a detailed description of each research area. (BP)

Application of InSAR and Gravimetry for Land Subsidence Hazard Zoning in Aguascalientes, Mexico

OpenAIRE

Pacheco-Martínez, Jesús; Cabral-Cano, Enrique; Wdowinski, Shimon; Hernández-Marín, Martín; Ortiz-Lozano, José; Zermeño-de-León, Mario

2015-01-01

In this work we present an application of InSAR and gravimetric surveys for risk management related to land subsidence and surface ground faulting generation. A subsidence velocity map derived from the 2007–2011 ALOS SAR imagery and a sediment thicknesses map obtained from the inversion of gravimetric data were integrated with a surface fault map to produce a subsidence hazard zoning in the city of Aguascalientes, Mexico. The resulting zoning is presented together with specific recommendation...

Differential substrate subsidence of the EnviHUT project pitched extensive green roof

Directory of Open Access Journals (Sweden)

Nečadová Klára

2017-01-01

Full Text Available In primary phase of testing building physical characteristics of the EnviHUT project extensive and semi-intensive roofs with 30° inclination occurred exceptional substrate subsidence. An extensive testing field with retaining geocell-system evinced differential subsidence of individual sectors after six months. Measured subsidence of installed substrate reached 40 % subsidence compared to originally designed height (intended layer thickness. Subsequent deformation of geocell-system additionally caused partial slide of substrate to drip edge area. These slides also influenced initial development of stonecrop plants on its surface. Except functional shortages the aesthetical function of the whole construction is influenced by the mentioned problem. The stated paper solves mentioned issues in view of installation method optimization, selection and modification of used roof substrate and in view of modification of geometric and building installed elements retaining system arrangement. Careful adjustment of roof system geometry and enrichment of original substrate fraction allow full functionality from pitched extensive green roof setting up. The modification scheme and its substantiation is a part of this technical study output.

Modeling of earth fissures caused by land subsidence due to groundwater withdrawal

Directory of Open Access Journals (Sweden)

B. B. Panda

2015-11-01

Full Text Available Land subsidence and earth fissures are phenomena related to groundwater withdrawal in a sedimentary basin. If the rock basement or basin lithology is irregular, both vertical and horizontal displacements can be induced due to differential settlement and tensile stresses appearing in the soil mass. If the differential settlement is of sufficient magnitude, earth fissuring can occur within tensile zones. The magnitudes of compaction and fissure geometry are closely related to the thickness and skeletal compressibility of fine-grained sediments within the aquifer system. Land subsidence and earth fissuring were modeled by employing a two-dimensional (2-D coupled seepage and stress-strain finite element analysis. The basin bedrock geometry, lithological variation, measurements of surface displacements, and changes in hydraulic head were the critical input parameter for the subsidence modeling. Simulation results indicate that strain had exceeded the approximate threshold for fissure formation of 0.02 to 0.06 % in the area of the identified fissures. The numerical model was used to predict future subsidence and potential earth fissures for flood control structures within the metro Phoenix area.

InSAR detects increase in surface subsidence caused by an Arctic tundra fire

Science.gov (United States)

Liu, Lin; Jafarov, Elchin E.; Schaefer, Kevin M.; Jones, Benjamin M.; Zebker, Howard A.; Williams, Christopher A.; Rogan, John; Zhang, Tingjun

2014-01-01

Wildfire is a major disturbance in the Arctic tundra and boreal forests, having a significant impact on soil hydrology, carbon cycling, and permafrost dynamics. This study explores the use of the microwave Interferometric Synthetic Aperture Radar (InSAR) technique to map and quantify ground surface subsidence caused by the Anaktuvuk River fire on the North Slope of Alaska. We detected an increase of up to 8 cm of thaw-season ground subsidence after the fire, which is due to a combination of thickened active layer and permafrost thaw subsidence. Our results illustrate the effectiveness and potential of using InSAR to quantify fire impacts on the Arctic tundra, especially in regions underlain by ice-rich permafrost. Our study also suggests that surface subsidence is a more comprehensive indicator of fire impacts on ice-rich permafrost terrain than changes in active layer thickness alone.

Environmental and economic effects of subsidence: Category 4, Project 1. Final report

Energy Technology Data Exchange (ETDEWEB)

Viets, V.F.; Vaughan, C.K.; Harding, R.C.

1979-05-01

A list of more than 70 subsidence areas was screened to select those areas which seemed to have the best potential for providing reliable data. The screening process is described in an appendix. Nine areas were selected for detailed case studies to collect all available data on the environmental and economic effects of the subsidence. Available information from the subsidence areas not selected as case studies was tabulated for each area and is included in an appendix. The nine case study areas are: Arizona; San Joaquin Valley, California; Baldwin Hills, California; Santa Clara Valley, California; Wilmington, California; Las Vegas Valley, Nevada; Houston-Galveston area, Texas; Mexico City, Mexico; and Wairakei, New Zealand. (MHR)

Regional Land Subsidence Analysis in Eastern Beijing Plain by InSAR Time Series and Wavelet Transforms

Directory of Open Access Journals (Sweden)

Mingliang Gao

2018-02-01

Full Text Available Land subsidence is the disaster phenomenon of environmental geology with regionally surface altitude lowering caused by the natural or man-made factors. Beijing, the capital city of China, has suffered from land subsidence since the 1950s, and extreme groundwater extraction has led to subsidence rates of more than 100 mm/year. In this study, we employ two SAR datasets acquired by Envisat and TerraSAR-X satellites to investigate the surface deformation in Beijing Plain from 2003 to 2013 based on the multi-temporal InSAR technique. Furthermore, we also use observation wells to provide in situ hydraulic head levels to perform the evolution of land subsidence and spatial-temporal changes of groundwater level. Then, we analyze the accumulated displacement and hydraulic head level time series using continuous wavelet transform to separate periodic signal components. Finally, cross wavelet transform (XWT and wavelet transform coherence (WTC are implemented to analyze the relationship between the accumulated displacement and hydraulic head level time series. The results show that the subsidence centers in the northern Beijing Plain is spatially consistent with the groundwater drop funnels. According to the analysis of well based results located in different areas, the long-term groundwater exploitation in the northern subsidence area has led to the continuous decline of the water level, resulting in the inelastic and permanent compaction, while for the monitoring wells located outside the subsidence area, the subsidence time series show obvious elastic deformation characteristics (seasonal characteristics as the groundwater level changes. Moreover, according to the wavelet transformation, the land subsidence time series at monitoring well site lags several months behind the groundwater level change.

Is There a Tectonic Component On The Subsidence Process In Morelia, Mexico?

Science.gov (United States)

Cabral-Cano, E.; Arciniega-Ceballos, A.; Diaz-Molina, O.; Garduno-Monroy, V.; Avila-Olivera, J.; Hernández-Madrigal, V.; Hernández-Quintero, E.

2009-12-01

Subsidence and faulting have affected cities in central Mexico for decades. This process causes substantial damages to the urban infrastructure, housing and large buildings, and is an important factor to be consider when planning urban development, land use zoning and hazard mitigation strategies. In Mexico, studies using InSAR and GPS based observations have shown that high subsidence areas are usually associated with the presence of thick lacustrine and fluvial deposits. In most cases the subsidence is closely associated with intense groundwater extraction that results in sediment consolidation. However, recent studies in the colonial city of Morelia in central Mexico show a different scenario, where groundwater extraction cannot solely explain the observed surface deformation. Our results indicate that a more complex interplay between sediment consolidation and tectonic forces is responsible for the subsidence and fault distribution within the city. The city of Morelia has experienced fault development recognized since the 80’s. This situation has led to the recognition of 9 NE-SW trending faults that cover most of its urbanized area. Displacement maps derived from differential InSAR analysis show that the La Colina fault is the highest subsiding area in Morelia with maximum annual rates over -35 mm/yr. However, lithological mapping and field reconnaissance clearly show basalts outcropping this area of high surface deformation. The subsurface characterization of the La Colina fault was carried out along 27 Ground Penetrating Radar (GPR) sections and 6 seismic tomography profiles. Assuming a constant, linear past behavior of the subsidence as observed by InSAR techniques, and based on the interpretation of the fault dislocation imaged by the shallow GPR and seismic tomography, it is suggested that the La Colina fault may have been active for the past 220-340 years and clearly pre-dates the intense water well extraction from the past century. These conditions

Rapid subsidence in damaging sinkholes: Measurement by high-precision leveling and the role of salt dissolution

Science.gov (United States)

Desir, G.; Gutiérrez, F.; Merino, J.; Carbonel, D.; Benito-Calvo, A.; Guerrero, J.; Fabregat, I.

2018-02-01

Investigations dealing with subsidence monitoring in active sinkholes are very scarce, especially when compared with other ground instability phenomena like landslides. This is largely related to the catastrophic behaviour that typifies most sinkholes in carbonate karst areas. Active subsidence in five sinkholes up to ca. 500 m across has been quantitatively characterised by means of high-precision differential leveling. The sinkholes occur on poorly indurated alluvium underlain by salt-bearing evaporites and cause severe damage on various human structures. The leveling data have provided accurate information on multiple features of the subsidence phenomena with practical implications: (1) precise location of the vaguely-defined edges of the subsidence zones and their spatial relationships with surveyed surface deformation features; (2) spatial deformation patterns and relative contribution of subsidence mechanisms (sagging versus collapse); (3) accurate subsidence rates and their spatial variability with maximum and mean vertical displacement rates ranging from 1.0 to 11.8 cm/yr and 1.9 to 26.1 cm/yr, respectively; (4) identification of sinkholes that experience continuous subsidence at constant rates or with significant temporal changes; and (5) rates of volumetric surface changes as an approximation to rates of dissolution-induced volumetric depletion in the subsurface, reaching as much as 10,900 m3/yr in the largest sinkhole. The high subsidence rates as well as the annual volumetric changes are attributed to rapid dissolution of high-solubility salts.

Energy research program 84

International Nuclear Information System (INIS)

1984-01-01

The energy research program 84 (EFP-84) is prepared by the Danish Ministry of Energy in order to continue the extension of the Danish energy research and development started through the former Trade Ministry's programs EM-1 (1976) and EM-2 (1978), and the Ministry of Energy's programs EFP-80, EFP-81, EFP-82 and EFP-83. The new program is a continuation of the activities in the period 1984-86 with a total budget of 112 mio. DKK. The program gives a brief description of background, principles, organization and financing, and a detailed description of each research area. (ln)

Energy research program 83

International Nuclear Information System (INIS)

1983-01-01

The energy research program 83 (EFP-83) is prepared by the Danish Ministry of Energy in order to continue the extension of the Danish energy research and development started through the former Trade Ministry's programs EM-1 (1976) and EM-2 (1978), and the Ministry of Energy's programs EFP-80, EFP-81 and EFP-82. The new program is a continuation of the activities in the period 1983-85 with a total budget of 111 mio. DKK. The program gives a brief description of background, principles, organization and financing, and a detailed description of each research area. (ln)

Energy research program 85

International Nuclear Information System (INIS)

1985-01-01

The energy research program 85 (EFP-85) is prepared by the Danish Ministry of Energy in order to continue the extension of the Danish energy research and development started through the former Trade Ministry's programs EM-1 (1976) and EM-2 (1978), and Ministry of Energy's programs EFP-80, EFP-81, EFP-82, EFP-83, and EFP-84. The new program is a continuation of the activities in the period 1985-87 with a total budget of 110 mio. DKK. The program gives a brief description of background, principles, organization and financing, and a detailed description of each research area. (ln)

Numerical analysis to determine the impact of land subsidence on high-speed railway routes in Beijing, China

Science.gov (United States)

Ye, C.; Yang, Y.; Tian, F.; Luo, Y.; Zhou, Y.

2015-11-01

More than 10 high-speed railway routes with top speeds of 300 km h-1 are expected to be operational from Beijing by the year 2020. However, the safety of these routes is affected by the occurrence of land subsidence. This paper focuses on the Beijing-Tianjin Intercity High-Speed Railway (BTR), the first high-speed railway in China, to analyze the operational safety of high-speed railway routes by analyzing both regional land subsidence and local differential subsidence caused by groundwater drawing. The Beijing construction stratum is mainly composed of cohesive soil, and the BTR has a maximum accumulative subsidence of > 800 mm and a maximum subsidence rate of > 80 mm a-1. In this paper, finite-element software ABAQUS is used to analyze groundwater drawdown and land subsidence caused by local water drawing, and its effect on the bearing capacity of railway bridge pile foundations and the orbit concrete supporting course. The analysis provides a technical basis for developing prevention and control engineering measures against land subsidence so as to guarantee the safe operation of these high-speed railway routes.

Stochastic Optimization of Supply Chain Risk Measures –a Methodology for Improving Supply Security of Subsidized Fuel Oil in Indonesia

Directory of Open Access Journals (Sweden)

Adinda Yuanita

2015-08-01

Full Text Available Monte Carlo simulation-based methods for stochastic optimization of risk measures is required to solve complex problems in supply security of subsidized fuel oil in Indonesia. In order to overcome constraints in distribution of subsidized fuel in Indonesia, which has the fourth largest population in the world—more than 250,000,000 people with 66.5% of productive population, and has more than 17,000 islands with its population centered around the nation's capital only—it is necessary to have a measurable and integrated risk analysis with monitoring system for the purpose of supply security of subsidized fuel. In consideration of this complex issue, uncertainty and probability heavily affected this research. Therefore, this research did the Monte Carlo sampling-based stochastic simulation optimization with the state-of-the-art "FIRST" parameter combined with the Sensitivity Analysis to determine the priority of integrated risk mitigation handling so that the implication of the new model design from this research may give faster risk mitigation time. The results of the research identified innovative ideas of risk based audit on supply chain risk management and new FIRST (Fairness, Independence, Reliable, Sustainable, Transparent parameters on risk measures. In addition to that, the integration of risk analysis confirmed the innovative level of priority on sensitivity analysis. Moreover, the findings showed that the new risk mitigation time was 60% faster than the original risk mitigation time.

Subsidence Monitoring in Seville (S Spain) Using Multi-Temporal InSAR

Science.gov (United States)

Ruiz-Armenteros, Antonio M.; Ruiz-Constan, Ana; Lamas-Fernandez, Francisco; Galindo-Zaldivar, Jesus; Sousa, Joaquim J.; Sanz de Galdeano, Carlos; Delgado, Manuel J.; Pedrera-Parias, Antonio; Martos-Rosillo, Sergio; Gil, Antonio J.; Caro-Cuenca, Miguel; Hanssen, Ramon F.

2016-08-01

Seville, with a metropolitan population of about 1.5 million, is the capital and largest city of Andalusia (S Spain). It is the 30th most populous municipality in the European Union and contains three UNESCO World Heritage Sites. The Seville harbour, located about 80 km from the Atlantic Ocean, is the only river port in Spain. The city is located on the plain of the Guadalquivir River. Using Multi-Temporal InSAR with ERS-1/2 and Envisat data a subsidence behavior is detected in the period 1992-2010. The geometry of the subsiding areas suggests that it should be conditioned by the fluvial dynamics of the Guadalquivir River and its tributaries. Facies distribution along the fluvial system (paleochannels, flood plains...), with different grain size and matrix proportion, may explain the relative subsidence between the different sectors.

The new three-dimensional subsidence influence function denoted by n-k-g

Energy Technology Data Exchange (ETDEWEB)

Nicieza, C.G.; Fernandez, M.I.A.; Diaz, A.M.; Vigil, A.E.A. [University of Oviedo, Asturias (Spain). Mining Engineering School

2005-04-01

This study presents a three-dimensional development of the n-k-g influence function with the aim of predicting subsidence phenomena and characterizing the shape and dimensions of the corresponding trough. The parameters 'n' and 'k' characterize the ground and 'g' is related to the gravity. This function depends on two physical concepts: the first is gravity, which characterizes the forces acting on the ground, and the second, the convergence of the roof and floor of the mine workings due to the stress state of the ground. Caving in of the roof generates direct subsidence, and the swelling of the floor, indirect subsidence, which allow us to establish the shape of the trough. The physical concepts introduced are fundamental in the mathematical implementation of the n-k-g influence function, allowing a more intuitive interpretation of the subsidence trough and notably facilitating the work of calibration, validation and sensitivity analysis. These concepts likewise allow the scope of application of influence functions to be extended to non-horizontal seams, also taking into account the quality of the rock mass and the presence of preferential sliding directions, in both the roof and the floor of the seam. This paper considers the physical concepts, then presents the three-dimensional implementation of the n-k-g influence function. Results obtained when calibrating the proposed numerical model with real data obtained from subsidence measurements in a coalmine in the Coal Basin of Asturias, Spain are given.

A theoretical model of subsidence caused by petroleum production: Big Hill Field, Jefferson County, Texas

International Nuclear Information System (INIS)

Hill, D.W.; Sharp, J.M. Jr.

1993-01-01

In the Texas Gulf Coastal Plain, there is a history of oil and gas production extending over 2 to 5 decades. Concurrent with this production history, there has been unprecedented population growth accompanied by vastly increased groundwater demands. Land subsidence on both local and regional bases in this geologic province has been measured and predicted in several studies. The vast majority of these studies have addressed the problem from the standpoint of groundwater usage while only a few have considered the effects of oil and gas production. Based upon field-based computational techniques (Helm, 1984), a model has been developed to predict land subsidence caused by oil and gas production. This method is applied to the Big Hill Field in Jefferson County, Texas. Inputs include production data from a series of wells in this field and lithologic data from electric logs of these same wells. Outputs include predicted amounts of subsidence, the time frame of subsidence, and sensitivity analyses of compressibility and hydraulic conductivity estimates. Depending upon estimated compressibility, subsidence, to date, is predicted to be as high as 20 cm. Similarly, depending upon estimated vertical hydraulic conductivity, the time frame may be decades for this subsidence. These same methods can be applied to other oil/gas fields with established production histories as well as new fields when production scenarios are assumed. Where subsidence has been carefully measured above petroleum reservoir, the model may be used inversely to calculate sediment compressibilities

Subsidence transition during the post-rift stage of the Dongpu Sag, Bohai Bay Basin, NE China: A new geodynamic model

Science.gov (United States)

Xu, Han; Wang, Xin-Wen; Yan, Dan-Ping; Qiu, Liang

2018-06-01

The Dongpu Sag, located in the Bohai Bay Basin, NE China, is a Cenozoic continental rift basin. The post-rift evolution of the Dongpu Sag is associated with the development of petroleum reservoirs and has implications for Neogene-Quaternary basin evolution along the eastern margin of Eurasia. To determine the nature and origin of post-rift subsidence in the Dongpu Sag, we apply backstripping, modified strain-rate inversion, and revised finite extension modelling techniques, using data from 14 real and synthetic wells that are intersected by three seismic lines. Our results reveal discrepancies by subsidence based on backstripping of well data (the observed subsidence) minus that predicted by modified strain-rate inversion and revised finite extension modelling (the predicted subsidence). During the Miocene, the observed subsidence was smaller than the predicted subsidence, leaving negative discrepancies referred to here as "insufficient subsidence" ranging from -343 to -96 m. In contrast, during the Pliocene-Quaternary the observed subsidence was greater than the predicted subsidence by +123 to +407 m, which left positive discrepancies referred to as "over-sufficient subsidence". Therefore, we infer a transition from insufficient to over-sufficient subsidence during the post-rift stage. Normal faulting that started at ca. 5.3 Ma is estimated to have produced only ∼20% of the over-sufficient subsidence. Therefore, the remaining over-sufficient subsidence, as well as the preceding insufficient subsidence and the transition between the two, were likely controlled by lithosphere processes. We propose a new tectonic model in which variations in the conditions (e.g. rate, direction, and angle) associated with subduction of the Pacific plate resulted in a change of heat flow decreasing from a linear to a curvilinear pattern, leading to a transition from insufficient to over-sufficient subsidence.

Long-Term Land Subsidence Monitoring of Beijing (China Using the Small Baseline Subset (SBAS Technique

Directory of Open Access Journals (Sweden)

Bo Hu

2014-04-01

Full Text Available Advanced techniques of multi-temporal InSAR (MT-InSAR represent a valuable tool in ground subsidence studies allowing remote investigation of the behavior of mass movements in long time intervals by using large datasets of SAR images covering the same area and acquired at different epochs. Beijing is susceptible to subsidence, producing undesirable environmental impacts and affecting dense population. Excessive groundwater withdrawal is thought to be the primary cause of land subsidence, and rapid urbanization and economic development, mass construction of skyscrapers, highways and underground engineering facilities (e.g., subway are also contributing factors. In this paper, a spatial–temporal analysis of the land subsidence in Beijing was performed using one of the MT-InSAR techniques, referred to as Small Baseline Subset (SBAS. This technique allows monitoring the temporal evolution of a deformation phenomenon, via the generation of mean deformation velocity maps and displacement time series from a data set of acquired SAR images. 52 C-band ENVISAT ASAR images acquired from June 2003 to August 2010 were used to produce a linear deformation rate map and to derive time series of ground deformation. The results show that there are three large subsidence funnels within this study area, which separately located in Balizhuang-Dajiaoting in Chaoyang district, Wangjing-Laiguangying Chaoyang district, Gaoliying Shunyi district. The maximum settlement center is Wangsiying-Tongzhou along the Beijing express; the subsidence velocity exceeds 110 mm/y in the LOS direction. In particular, we compared the achieved results with leveling measurements that are assumed as reference. The estimated long-term subsidence results obtained by SBAS approach agree well with the development of the over-exploitation of ground water, indicating that SBAS techniques is adequate for the retrieval of land subsidence in Beijing from multi-temporal SAR data.

Energy research program 86

International Nuclear Information System (INIS)

1986-01-01

The energy research program 86 (EFP-86) is prepared by the Danish Ministry of Energy in order to continue the extension of the Danish energy research and development started through the former Trade Ministry's programs EM-1 (1976) and EM-2 (1978), and the Ministry of Energy's programs EFP-80, EFP-81, EFP-82, EFP-83, EFP-84, and EFP-85. The new program is a continuation of the activities in the period 1986-88 with a total budget of 116 mio. DKK. The program gives a brief description of background, principles, organization and financing, and a detailed description of each research area. (ln)

Research of the refilling use in order to reduce the subsidence effects in the surface; Investigacion del Empleo de Relleno Consolidado para Reducir los Efectos de la Subsidencia en Superficie

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-11-01

The development of the research has been performed with a practical immediate purpose in the works of the Company Coto Minero de Narcea, S. A., a producer of anthracite in Asturias West Bassin. This is due to the fact that the work mining of the 2, 3 and 6 seams, essential to continue the production activities, is at present almost in vertical coincidence with surface installations of the mine making it necessary to use a filling material specially selected and layed in the works to minimize the subsidence effects. The prediction of these effects in order to reduce them to admissible bounds has been made through the application of the computer program SUBSIMCO, developed on the basis of the empirical calculation methods and the experience collected by the VNIMI Institute of Leningrad. The results controlled up to now, through accurate measuring, show a satisfactory coincidence with the predictions of theoretical calculations, proving at the same time the effectiveness of the filling process designed and the correct adaptation of the calculus method.

Energy research program 80

International Nuclear Information System (INIS)

1980-01-01

The energy research program 80 contains an extension of the activities for the period 1980-82 within a budget of 100 mio.kr., that are a part of the goverment's employment plan for 1980. The research program is based on a number of project proposals, that have been collected, analysed, and supplemented in October-November 1979. This report consists of two parts. Part 1: a survey of the program, with a brief description of the background, principles, organization and financing. Part 2: Detailed description of the different research programs. (LN)

Current Land Subsidence in Tianjin, China Recorded by Three Continuous GPS stations (2010-2014)

Science.gov (United States)

Jia, X.; Jing, Q.; Yan, B.; Yu, J.; Gan, W.; Wang, G.

2014-12-01

In the past two decades, Global Positioning System (GPS) technologies have been frequently applied to urban subsidence studies, both as a complement, and an alternative to conventional surveying methods. These studies have demonstrated that high-accuracy GPS techniques are an efficient tool in tracking long-term land subsidence. A great number of Continuously Operating Reference GPS Stations (CORS) have been installed in China during the past five years. Considerable land subsidence has been observed from CORS stations installed in several large cities. This study investigated GPS time series observed at three CORS in Tianjin: TJBD (2010-2014), TJBH (2010-2014), and TJWQ (2010-2014). Tianjin is one of the largest cities that is experiencing severe land subsidence problems in China. The observations at the three GPS sites indicate different subsidence rates. The average subsidence rate over four years are 0.2 cm/year at TJBD, 2 cm/year at TJBH, and 4.4 cm/year at TJWQ. The GPS station TJBD is located at Baodi, Tianjin. This area is the least economically developed and have the smallest population compared to the other two areas. Over 80% of water usage in Baodi is for agriculture and only less than 15% is from groundwater. The rapid subsidence at TJBH and TJWQ were caused by huge groundwater withdrawals associate with rapid urban and industrial developments in Binhai and Wuqing. Wuqing district, with a unique location advantage called "Corridor of Beijing and Tianjin", has been experiencing major urbanization. The population has reached 1,053,300 and the water usage has reached 350 million cubic meters in 2012. Over 25% of water usage is from groundwater. Significant annual and half-annual seasonal ground surface fluctuation has been observed from all three GPS stations. The peak-to-peak amplitude of the annual signal is 1.5 cm.

Estimating the Impact of Low-Income Universal Service Programs

OpenAIRE

Daniel A. Ackerberg; David R. DeRemer; Michael H. Riordan; Gregory L. Rosston; Bradley S. Wimmer

2013-01-01

This policy study uses U.S. Census microdata to evaluate how subsidies for universal telephone service vary in their impact across low-income racial groups, gender, age, and home ownership. Our demand specification includes both the subsidized monthly price (Lifeline program) and the subsidized initial connection price (Linkup program) for local telephone service. Our quasi-maximum likelihood estimation controls for location differences and instruments for price endogeneity. The microdata all...

Equipment qualification research program: program plan

International Nuclear Information System (INIS)

Dong, R.G.; Smith, P.D.

1982-01-01

The Lawrence Livermore National Laboratory (LLNL) under the sponsorship of the US Nuclear Regulatory Commission (NRC) has developed this program plan for research in equipment qualification (EQA). In this report the research program which will be executed in accordance with this plan will be referred to as the Equipment Qualification Research Program (EQRP). Covered are electrical and mechanical equipment under the conditions described in the OBJECTIVE section of this report. The EQRP has two phases; Phase I is primarily to produce early results and to develop information for Phase II. Phase I will last 18 months and consists of six projects. The first project is program management. The second project is responsible for in-depth evaluation and review of EQ issues and EQ processes. The third project is responsible for detailed planning to initiate Phase II. The remaining three projects address specific equipment; i.e., valves, electrical equipment, and a pump

Medical Research Volunteer Program (MRVP): innovative program promoting undergraduate research in the medical field.

Science.gov (United States)

Dagher, Michael M; Atieh, Jessica A; Soubra, Marwa K; Khoury, Samia J; Tamim, Hani; Kaafarani, Bilal R

2016-06-06

Most educational institutions lack a structured system that provides undergraduate students with research exposure in the medical field. The objective of this paper is to describe the structure of the Medical Research Volunteer Program (MRVP) which was established at the American University of Beirut, Lebanon, as well as to assess the success of the program. The MRVP is a program that targets undergraduate students interested in becoming involved in the medical research field early on in their academic career. It provides students with an active experience and the opportunity to learn from and support physicians, clinical researchers, basic science researchers and other health professionals. Through this program, students are assigned to researchers and become part of a research team where they observe and aid on a volunteer basis. This paper presents the MRVP's four major pillars: the students, the faculty members, the MRVP committee, and the online portal. Moreover, details of the MRVP process are provided. The success of the program was assessed by carrying out analyses using information gathered from the MRVP participants (both students and faculty). Satisfaction with the program was assessed using a set of questions rated on a Likert scale, ranging from 1 (lowest satisfaction) to 5 (highest satisfaction). A total of 211 students applied to the program with a total of 164 matches being completed. Since the beginning of the program, three students have each co-authored a publication in peer-reviewed journals with their respective faculty members. The majority of the students rated the program positively. Of the total number of students who completed the program period, 35.1 % rated the effectiveness of the program with a 5, 54.8 % rated 4, and 8.6 % rated 3. A small number of students gave lower ratings of 2 and 1 (1.1 % and 0.4 %, respectively). The MRVP is a program that provides undergraduate students with the opportunity to learn about research firsthand

Magnitude and extent of land subsidence in central Mexico revealed by regional InSAR ALOS time-series survey

Science.gov (United States)

Chaussard, E.; Wdowinski, S.; Amelung, F.; Cabral-Cano, E.

2013-05-01

Massive groundwater extraction is very common in Mexico and is well known to result in land subsidence. However, most surveys dedicated to land subsidence focus on one single city, mainly Mexico City, and thus fail to provide a comprehensive picture of the problem. Here we use a space-based radar remote sensing technique, known as Interferometric Synthetic Aperture Radar (InSAR) to detect land subsidence in the entire central Mexico area. We used data from the Japanese satellite ALOS, processed over 600 SAR images acquired between 2007-2011 and produced over 3000 interferograms to cover and area of 200,000 km2 in central Mexico. We identify land subsidence in twenty-one areas, including seventeen cities, namely from east to west, Puebla, Mexico city, Toluca de Lerdo, Queretaro, San Luis de la Paz, south of San Luis de la Paz, Celaya, south of Villa de Reyes, San Luis Potosi, west of Villa de Arista, Morelia, Salamanca, Irapuato, Silao, Leon, Aguascalientes, north of Aguascalientes, Zamora de Hidalgo, Guadalajara, Ahuacatlan, and Tepic. Subsidence rates of 30 cm/yr are observed in Mexico City, while in the other locations typical rates of 5-10 cm/yr are noticed. Regional surveys of this type are necessary for the development of hazard mitigation plans and efficient use of ground-based monitoring. We additionally correlate subsidence with land use, surface geology, and faults distribution and suggest that groundwater extraction for agricultural, urban, and industrial uses are the main causes of land subsidence. We also reveal that the limits of the subsiding areas often correlate with existing faults, motion on these faults being driven by water extraction rather than by tectonic activity. In all the subsiding locations we observe high ground velocity gradients emphasizing the significant risks associated with land subsidence in central Mexico. Averaged 2007-2011 ground velocity map from ALOS InSAR time-series in central Mexico, revealing land subsidence in 21

InSAR Remote Sensing of Localized Surface Layer Subsidence in New Orleans, LA

Science.gov (United States)

An, K.; Jones, C. E.; Blom, R. G.; Kent, J. D.; Ivins, E. R.

2015-12-01

More than half of Louisiana's drinking water is dependent on groundwater, and extraction of these resources along with high oil and gas production has contributed to localized subsidence in many parts of New Orleans. This increases the vulnerability of levee failure during intense storms such as Hurricane Katrina in 2005, before which rapid subsidence had already been identified and contributed to the failing levees and catastrophic flooding. An interferogram containing airborne radar data from NASA's UAVSAR was combined with local geographic information systems (GIS) data for 2009-12 to help identify the sources of subsidence and mask out unrelated features such as surface water. We have observed the highest vertical velocity rates at the NASA Michoud Assembly Facility (high water use) and Norco (high oil/gas production). Many other notable features such as the: Bonnet-Carre Spillway, MRGO canal, levee lines along the Lower 9th Ward and power plants, are also showing concerning rates of subsidence. Even new housing loads, soil type differences, and buried beach sands seem to have modest correlations with patterns seen in UAVSAR. Current hurricane protection and coastal restoration efforts still have not incorporated late 20th century water level and geodetic data into their projections. Using SAR interferometry and local GIS datasets, areas of subsidence can be identified in a more efficient and economical manner, especially for emergency response.

Reclamation planning for abandoned mining subsidence lands in eastern China: a case study

International Nuclear Information System (INIS)

Hu, Z.; Gu, H.

1995-01-01

China has a long history of coal mining and more than 96% of coal output is taken from underground mines each year. With the excavation of coal from underground, severe subsidence often results, which produces many subsidence lands. This paper explores the principle and methods of reclamation planning for abandoned mining subsidence lands and presents a case study in eastern China. A 373 ha of abandoned mining subsidence land in Anhui province was selected as an experiment site. Since China is a developing country and land shortage is severe in this area, the high economic benefits from the reclaimed land was the final reclamation goal. Based on the topography of subsidence lands, some parts of the abandoned lands were lands or lake-like troughs, restoring farmlands and fishponds were chosen as post-reclamation land uses. The elevation of reclaimed lands was the key for restoring farmland successfully because of the high underground water level in this area, and the optimum fishpond size and side-slope design were the keys to reach high reclamation income. The HDP (Hydraulic Dredge Pump) reclamation technique was used for restoring farmland and creating fishpond. A farming and aquaculture plan for high economic benefits was also designed. This project will make farmers, who own the lands, richer through reclamation. 3 refs., 5 figs., 1 tab

Subsidence, Sea Level Rise, and Seismicity in the Sacramento–San Joaquin Delta

Directory of Open Access Journals (Sweden)

Jeffrey Mount

2005-03-01

Full Text Available Anthropogenic accommodation space, or that space in the Delta that lies below sea level and is filled neither with sediment nor water, serves as a useful measure of the regional consequences of Delta subsidence and sea level rise. Microbial oxidation and compaction of organic-rich soils due to farming activity is the primary cause of Delta subsidence. During the period 1900-2000, subsidence created approximately 2.5 billion cubic meters of anthropogenic accommodation space in the Delta. From 2000-2050, subsidence rates will slow due to depletion of organic material and better land use practices. However, by 2050 the Delta will contain more than 3 billion cubic meters of anthropogenic accommodation space due to continued subsidence and sea level rise. An Accommodation Space Index, which relates subaqueous accommodation space to anthropogenic accommodation space, provides an indicator of past and projected Delta conditions. While subsidence and sea level rise create increasing anthropogenic accommodation space in the Delta, they also lead to a regional increase in the forces that can cause levee failure. Although these forces take many forms, a Levee Force Index can be calculated that is a proxy for the cumulative forces acting on levees. The Levee Force Index increases significantly over the next 50 years demonstrating regional increases in the potential for island flooding. Based on continuing increases in the Levee Force Index and the Accommodation Space Index, and limited support for Delta levee upgrades, there will be a tendency for increases in and impacts of island flooding, with escalating costs for repairs. Additionally, there is a two-in-three chance that 100-year recurrence interval floods or earthquakes will cause catastrophic flooding and significant change in the Delta by 2050. Currently, the California Bay-Delta Authority has no overarching policy that addresses the consequences of, and potential responses to, gradual or abrupt

The future of subsidence modelling: compaction and subsidence due to gas depletion of the Groningen gas field in the Netherlands

NARCIS (Netherlands)

Thienen-Visser, K. van; Fokker, P.A.

2017-01-01

The Groningen gas field has shown considerable compaction and subsidence since starting production in the early 1960s. The behaviour is understood from the geomechanical response of the reservoir pressure depletion. By integrating surface movement measurements and modelling, the model parameters can

Radon Research Program, FY 1991

International Nuclear Information System (INIS)

1992-03-01

The scientific information being sought in this program encompasses research designed to determine radon availability and transport outdoors, modeling transport into and within buildings, physics and chemistry of radon and radon progeny, dose response relationships, lung cancer risk, and mechanisms of radon carcinogenesis. The main goal of the DOE/OHER Radon Research Program is to develop information to reduce these uncertainties and thereby provide an improved health risk estimate of exposure to radon and its progeny as well as to provide information useful in radon control strategies. Results generated under the Program were highlighted in a National Research Council report on radon dosimetry. The study concluded that the risk of radon exposure is 30% less in homes than in mines. This program summary of book describes the OHER FY-1991 Radon Research Program. It is the fifth in an annual series of program books designed to provide scientific and research information to the public and to other government agencies on the DOE Radon Research Program

Ecological Research Division, Marine Research Program

Energy Technology Data Exchange (ETDEWEB)

1980-05-01

This report presents program summaries of the various projects sponsored during 1979 by the Marine Research Program of the Ecological Research Division. Program areas include the effects of petroleum hydrocarbons on the marine environment; a study of the baseline ecology of a proposed OTEC site near Puerto Rico; the environmental impact of offshore geothermal energy development; the movement of radionuclides through the marine environment; the environmental aspects of power plant cooling systems; and studies of the physical and biological oceangraphy of the continental shelves bordering the United States.

Ecological Research Division, Marine Research Program

International Nuclear Information System (INIS)

1980-05-01

This report presents program summaries of the various projects sponsored during 1979 by the Marine Research Program of the Ecological Research Division. Program areas include the effects of petroleum hydrocarbons on the marine environment; a study of the baseline ecology of a proposed OTEC site near Puerto Rico; the environmental impact of offshore geothermal energy development; the movement of radionuclides through the marine environment; the environmental aspects of power plant cooling systems; and studies of the physical and biological oceangraphy of the continental shelves bordering the United States

On Assessment and Estimation of Potential Losses due to Land Subsidence in Urban Areas of Indonesia

Science.gov (United States)

Abidin, Hasanuddin Z.; Andreas, Heri; Gumilar, Irwan; Sidiq, Teguh P.

2016-04-01

Land subsidence is natural-anthropogenic hazard affecting several large urban areas in Indonesia, i.e. Jakarta, Bandung and Semarang. Geodetic based results from various techniques (e.g. Leveling, GPS and InSAR) show that land subsidence rates in all three cities generally have spatial and temporal variations, and their magnitude is in average about 5-10 cm/year. The impacts of subsidence in those cities can be seen in the field in various forms such as cracking of permanent constructions and roads, tilting of houses and buildings, 'sinking' of houses and buildings, changes in river canal and drain flow systems, wider expansion of coastal and/or inland flooding areas, and increased inland sea water intrusion. These impacts can be categorized into infrastructure, environmental, economic, and social impacts. The potential losses due to land subsidence in urban areas are actually quite significant. Related infrastructural, social and environmental costs due to direct and indirect impacts of land subsidence are economically quite significant, and can not be underestimated in sustainable urban development. The planning, development and maintenance costs of building and infrastructures in the affected areas are usually much higher than the normal situation. The collateral impact of coastal subsidence in Jakarta and Semarang, in the form of coastal flooding during high tides is also quite damaging. This repeated coastal flooding in several areas along the coast will deteriorate the structure and function of building and infrastructures, badly influences the quality of the living environment and life (e.g. health and sanitation condition), and also disrupts economic and social activities in the affected areas. As in the case of Bandung, inland subsidence also has a quite significant impact on inland flooding phenomena, since it will theoretically lead to expanded coverage and deeper water depth of flooded (inundated) areas. Since the direct and indirect impacts of

Evaluating Land Subsidence Rates and Their Implications for Land Loss in the Lower Mississippi River Basin

Directory of Open Access Journals (Sweden)

Lei Zou

2015-12-01

Full Text Available High subsidence rates, along with eustatic sea-level change, sediment accumulation and shoreline erosion have led to widespread land loss and the deterioration of ecosystem health around the Lower Mississippi River Basin (LMRB. A proper evaluation of the spatial pattern of subsidence rates in the LMRB is the key to understanding the mechanisms of the submergence, estimating its potential impacts on land loss and the long-term sustainability of the region. Based on the subsidence rate data derived from benchmark surveys from 1922 to 1995, this paper constructed a subsidence rate surface for the region through the empirical Bayesian kriging (EBK interpolation method. The results show that the subsidence rates in the region ranged from 1.7 to 29 mm/year, with an average rate of 9.4 mm/year. Subsidence rates increased from north to south as the outcome of both regional geophysical conditions and anthropogenic activities. Four areas of high subsidence rates were found, and they are located in Orleans, Jefferson, Terrebonne and Plaquemines parishes. A projection of future landscape loss using the interpolated subsidence rates reveals that areas below zero elevation in the LMRB will increase from 3.86% in 2004 to 19.79% in 2030 and 30.88% in 2050. This translates to a growing increase of areas that are vulnerable to land loss from 44.3 km2/year to 240.7 km2/year from 2011 to 2050. Under the same scenario, Lafourche, Plaquemines and Terrebonne parishes will experience serious loss of wetlands, whereas Orleans and Jefferson parishes will lose significant developed land, and Lafourche parish will endure severe loss of agriculture land.

The impact of subsidence on straight and curved modular cementless revision stems in hip revision surgery.

Science.gov (United States)

Fraile Suari, A; Gil González, S; Pérez Prieto, D; León García, A; Mestre Cortadellas, C; Tey Pons, M; Marqués López, F

Subsidence is one of the potential complications in femoral stem revision total hip arthroplasty surgery, and can affect stability and osseointegration. A retrospective study was conducted on the outcomes at one year and 5 years (specifically subsidence and clinical relevance) of 40 consecutive femoral total hip arthroplasty revisions, comparing two modular cementless revision stems, Straight vs. Curved, with 20 patients in each group. No mechanical failure was observed, and there was an improvement in functional outcomes. Mean radiological subsidence was 9.9±4.9mm (straight=10.75mm vs. curved=9.03mm), with no statistically significant difference between groups (p=0,076). Fourteen patients (35%) had ≥10mm of subsidence, up to a maximum of 22mm. The subsidence found in this study is similar to published series, with no short-term clinical manifestations, or an increased number of complications or stem loosening in either the Straight or Curved group. No differences in subsidence were observed at one year and 5 years after surgery between the 2 types of stems. Copyright © 2017 SECOT. Publicado por Elsevier España, S.L.U. All rights reserved.

Retailers in social program strategy: the case of family planning.

Science.gov (United States)

Black, T R; Farley, J U

1977-01-01

The provision of contraceptive agents and devices through hospitals and clinics is not a cost-efficient procedure, therefore the distribution through retailers in a preexisting network is an attractive prospect. To really distribute contraceptives, e.g., birth control pills, the retailer would have to be trained in a format of questions. Two studies of retail marketing were conducted, one in Jamaica for condoms and one in Kenya where a subsidized marketing program for condoms was started in rural areas. More urban shops, which were larger in size, carried condoms than rural shops. Retailers in both areas were completely oriented to their immediate vicinity. Their concerns were with volume and with aggregate demand both before and after subsidized programs. The distribution system requires the additional support of advertising and marketing, but since the structure is in place it can be used with relatively little capital outlay. Research of retailers' attitudes and perceptions is inexpensive and often indicates customer preference and local market conditions.

GROUND SUBSIDENCE MONITORING WITH MT-InSAR AND MECHANISM INVERSION OVER XI’AN, CHINA

Directory of Open Access Journals (Sweden)

M. M. Peng

2018-04-01

Full Text Available The ancient Xi’an, China, has been suffering severe land subsidence and ground fissure hazards since the 1960s, which has affected the safety of Subways. Multi-sensor SAR data are conducted to monitor the latest complex ground deformation and its influence on subway line No.3 over Xi’an. Annual deformation rates have been retrieved to reveal the spatiotemporal evolution of ground subsidence in Xi’an city from 2013 to 2017. Meanwhile, the correlation between land subsidence and ground fissures are analyzed by retrieving the deformation differences in both sides of the fissures. Besides, the deformation along subway line No. 3 is analyzed, and the fast deformation section is quantitatively studied. Finally, a flat lying sill model with distributed contractions is implemented to model the InSAR deformation over YHZ subsidence center, which manifests that the ground deformation is mainly caused by groundwater withdrawal.

Coal mine subsidence: effects of mitigation on crop yields. [USA - Illinois

Energy Technology Data Exchange (ETDEWEB)

Darmody, R.G.; Hetzler, R.T.; Simmons, F.W. (Illinois Univ., Urbana, IL (USA). Dept. of Agronomy)

1992-01-01

Subsidence from longwall underground coal mining adversely impacts agricultural land by creating wet or ponded areas. While most subsided areas show little impact, some localized places, usually less than 1.5 ha in size, may experience total crop failure. Coal companies mitigate subsidence damaged cropland by installing drainage waterways or by adding fill material to raise the grade. The objective of this study was to test the effectiveness of mitigation in restoring corn and soybean yields to pre-mined levels. Fourteen sites in southern Illinois were selected for study. Corn ([ital Zea mays] L.) and soybean ([ital Glycine max] L.) yields from mitigated and nearby undisturbed areas were compared for four years. Results varied due to differing weather and site conditions. Mean corn yields overall, however were significantly ([alpha]0.05) lower on mitigated areas. There was no significant difference in overall mean soybean yields. Soil fertility levels were similar and did not account for yield differences. 14 refs., 1 fig., 7 tabs.

Subsidence Induced Faulting Hazard Zonation Using Persistent Scatterer Interferometry and Horizontal Gradient Mapping in Mexican Urban Areas

Science.gov (United States)

Cabral-Cano, E.; Cigna, F.; Osmanoglu, B.; Dixon, T.; Wdowinski, S.

2011-12-01

Subsidence and faulting have affected Mexico city for more than a century and the process is becoming widespread throughout larger urban areas in central Mexico. This process causes substantial damages to the urban infrastructure and housing structures and will certainly become a major factor to be considered when planning urban development, land use zoning and hazard mitigation strategies in the next decades. Subsidence is usually associated with aggressive groundwater extraction rates and a general decrease of aquifer static level that promotes soil consolidation, deformation and ultimately, surface faulting. However, local stratigraphic and structural conditions also play an important role in the development and extension of faults. In all studied cases stratigraphy of the uppermost sediment strata and the structure of the underlying volcanic rocks impose a much different subsidence pattern which is most suitable for imaging through satellite geodetic techniques. We present examples from several cities in central Mexico: a) Mexico-Chalco. Very high rates of subsidence, up to 370 mm/yr are observed within this lacustrine environment surrounded by Pliocene-Quaternary volcanic structures. b) Aguascalientes where rates up to 90 mm/yr in the past decade are observed, is controlled by a stair stepped N-S trending graben that induces nucleation of faults along the edges of contrasting sediment package thicknesses. c) Morelia presents subsidence rates as high as 80 mm/yr. Differential deformation is observed across major basin-bounding E-W trending faults and with higher subsidence rates on their hanging walls, where the thickest sequences of compressible Quaternary sediments crop out. Our subsidence and faulting study in urban areas of central Mexico is based on a horizontal gradient analysis using displacement maps from Persistent Scatterer InSAR that allows definition of areas with high vulnerability to surface faulting. Correlation of the surface subsidence pattern

Releveling and behavior of strap-retrofitted damaged test foundations exposed to mine subsidence

International Nuclear Information System (INIS)

Marino, G.G.

1997-01-01

Test foundation walls were constructed in an area of planned subsidence. These crawl space-sized block bearing walls were located in the tension zone of a longwall panel. The test walls were 1.2 m (40 ft) long and were vertically loaded on top with soil binds to simulate the weight of a house. As the longwall proceeded past these test foundations, subsidence movements damaged the test structures. These damaged foundations were then structurally and aesthetically repaired by using a steel strap retrofit and applying a cementitious surface coating. The repaired test foundations underwent significant subsequent subsidence as an adjacent longwall was mined beneath. The response of the repaired foundation is summarized in this paper. The steel straps were also used to relevel another set of the test foundations after they were tilted and damaged by subsidence. First, the straps were applied to the block bearing walls, and then wall jacks were used to lift the upper portion of the walls to a level position. This releveling procedure is outlined with the results

Application of decision tree model for the ground subsidence hazard mapping near abandoned underground coal mines.

Science.gov (United States)

Lee, Saro; Park, Inhye

2013-09-30

Subsidence of ground caused by underground mines poses hazards to human life and property. This study analyzed the hazard to ground subsidence using factors that can affect ground subsidence and a decision tree approach in a geographic information system (GIS). The study area was Taebaek, Gangwon-do, Korea, where many abandoned underground coal mines exist. Spatial data, topography, geology, and various ground-engineering data for the subsidence area were collected and compiled in a database for mapping ground-subsidence hazard (GSH). The subsidence area was randomly split 50/50 for training and validation of the models. A data-mining classification technique was applied to the GSH mapping, and decision trees were constructed using the chi-squared automatic interaction detector (CHAID) and the quick, unbiased, and efficient statistical tree (QUEST) algorithms. The frequency ratio model was also applied to the GSH mapping for comparing with probabilistic model. The resulting GSH maps were validated using area-under-the-curve (AUC) analysis with the subsidence area data that had not been used for training the model. The highest accuracy was achieved by the decision tree model using CHAID algorithm (94.01%) comparing with QUEST algorithms (90.37%) and frequency ratio model (86.70%). These accuracies are higher than previously reported results for decision tree. Decision tree methods can therefore be used efficiently for GSH analysis and might be widely used for prediction of various spatial events. Copyright © 2013. Published by Elsevier Ltd.

Stress triggering of earthquakes and subsidence in the Louisiana coastal zone due to hydrocarbon production

Science.gov (United States)

Mallman, Ellen P.

This thesis presents contributions towards better understanding of the interaction between earthquakes through elastic stress triggering and the role of hydrocarbon production on subsidence and land loss in southern Louisiana. The first issue addressed in this thesis is that of the role of static stress changes on earthquake triggering. The first study investigated whether observed changes in seismicity rate following the 1992 Landers, California and 1995 Kobe, Japan earthquakes are accurately predicted by elastic Coulomb stress transfer models. The analyses found that for all the tested DeltaCFS models wherever seismicity rate changes could be resolved the rate increased regardless of whether the DeltaCFS theoretically promoted or inhibited failure. The second study the common definition of a stress shadow was extended to independently test the stress shadow hypothesis using a global catalog of seismicity. The analyses indicated that while stress shadows are subtle, they are present in the global catalog. It also explains why "classical" stress shadows, similar to what was observed following the 1906 San Francisco earthquake are rarely observed for individual main shocks. The second issue addressed in this thesis is the role of hydrocarbon production on subsidence and land loss in the Louisiana Coastal Zone. The two studies in this thesis extend previous work by modeling the effect of oil and gas production in the region in two ways. First, multiple producing oil and gas fields and multiple epochs of leveling data are considered to provide constraints on predicted subsidence. Second, the role of compaction of the reservoir bounding shales on the regional subsidence signal is included. The results of the two studies on the role of hydrocarbon production on subsidence in the Louisiana Coastal Zone indicate that regional models of subsidence must include the effects of production-induced subsidence due to both sands and shales, but that this can not account for the

Mapping Ground Subsidence Phenomena in Ho Chi Minh City through the Radar Interferometry Technique Using ALOS PALSAR Data

Directory of Open Access Journals (Sweden)

Dinh Ho Tong Minh

2015-07-01

Full Text Available The rapidly developing urbanization since the last decade of the 20th century has led to extensive groundwater extraction, resulting in subsidence in Ho Chi Minh City, Vietnam. Recent advances in multi-temporal spaceborne SAR interferometry, especially with a persistent scatters interferometry (PSI approach, has made this a robust remote sensing technique for measuring large-scale ground subsidence with millimetric accuracy. This work has presented an advanced PSI analysis, to provide an unprecedented spatial extent and continuous temporal coverage of the subsidence in Ho Chi Minh City from 2006 to 2010. The study shows that subsidence is most severe in the Holocene silt loam areas along the Sai Gon River and in the southwest of the city. The groundwater extraction resulting from urbanization and urban growth is mainly responsible for the subsidence. Subsidence in turn leads to more flooding and water nuisance. The correlation between the reference leveling velocity and the estimated PSI result is R2 = 0.88, and the root mean square error is 4.3 (mm/year, confirming their good agreement. From 2006 to 2010, the estimation of the average subsidence rate is -8.0 mm/year, with the maximum value up to -70 mm/year. After four years, in regions along Sai Gon River and in the southwest of the city, the land has sunk up to -12 cm. If not addressed, subsidence leads to the increase of inundation, both in frequency and spatial extent. Finally, regarding climate change, the effects of subsidence should be considered as appreciably greater than those resulting from rising sea level. It is essential to consider these two factors, because the city is inhabited by more than 7.5 million people, where subsidence directly impacts urban structures and infrastructure.

Radon Research Program, FY-1990

International Nuclear Information System (INIS)

1991-03-01

The Department of Energy (DOE) Office of Health and Environmental Research (OHER) has established a Radon Research Program with the primary objectives of acquiring knowledge necessary to improve estimates of health risks associated with radon exposure and also to improve radon control. Through the Radon Research Program, OHER supports and coordinates the research activities of investigators at facilities all across the nation. From this research, significant advances are being made in our understanding of the health effects of radon. OHER publishes this annual report to provide information to interested researchers and the public about its research activities. This edition of the report summarizes the activities of program researchers during FY90. Chapter 2 of this report describes how risks associated with radon exposure are estimated, what assumptions are made in estimating radon risks for the general public, and how the uncertainties in these assumptions affect the risk estimates. Chapter 3 examines how OHER, through the Radon Research Program, is working to gather information for reducing the uncertainties and improving the risk estimates. Chapter 4 highlights some of the major findings of investigators participating in the Radon Research Program in the past year. And, finally, Chapter 5 discusses the direction in which the program is headed in the future. 20 figs

Time series analysis of Mexico City subsidence constrained by radar interferometry

Science.gov (United States)

Doin, Marie-Pierre; Lopez-Quiroz, Penelope; Yan, Yajing; Bascou, Pascale; Pinel, Virginie

2010-05-01

In Mexico City, subsidence rates reach up to 40 cm/yr mainly due to soil compaction led by the over exploitation of the Mexico Basin aquifer. The Mexico Valley, an endoreic basin surrounded by mountains, was in the past covered by large lakes. After the Spanish conquest, the lakes have almost completely disappeared, being progressively replaced by buildings of the current Mexican capital. The simplified hydrogeologic structure includes a superficial 50 to 300 m thick lacustrine aquitard overlying a thicker aquifer made of alluvial deposits. The aquitard layer plays a crucial role in the subsidence process due to the extremely high compressibility of its clay deposits separated by a less compressible sand layer where the biggest buildings of the city are anchored. The aquifer over-exploitation leads to a large scale 30m depression of its piezometric level, inducing water downwards flow in the clays, yielding compaction and subsidence. In order to quantitatively link subsidence to water pumping, the Mexico city subsidence needs to be mapped and analyzed through space and time. We map its spatial and temporal patterns by differential radar interferometry, using 38 ENVISAT images acquired between end of 2002 and beginning of 2007. We employ both a Permanent Scatterer (PS) and a small baseline (SBAS) approach. The main difficulty consists in the severe unwrapping problems mostly due to the high deformation rate. We develop a specific SBAS approach based on 71 differential interferograms with a perpendicular baseline smaller than 500 m and a temporal baseline smaller than 9 months, forming a redundant network linking all images: (1) To help the unwrapping step, we use the fact that the deformation shape is stable for similar time intervals during the studied period. As a result, a stack of the five best interferograms can be used to reduce the number of fringes in wrapped interferograms. (2) Based on the redundancy of the interferometric data base, we quantify the

Physical Research Program: research contracts and statistical summary

International Nuclear Information System (INIS)

1975-01-01

The physical research program consists of fundamental theoretical and experimental investigations designed to support the objectives of ERDA. The program is directed toward discovery of natural laws and new knowledge, and to improved understanding of the physical sciences as related to the development, use, and control of energy. The ultimate goal is to develop a scientific underlay for the overall ERDA effort and the fundamental principles of natural phenomena so that these phenomena may be understood and new principles, formulated. The physical research program is organized into four functional subprograms, high-energy physics, nuclear sciences, materials sciences, and molecular sciences. Approximately four-fifths of the total physical research program costs are associated with research conducted in ERDA-owned, contractor-operated federally funded research and development centers. A little less than one-fifth of the costs are associated with the support of research conducted in other laboratories

Research results of the Optimiturve research program in 1991

International Nuclear Information System (INIS)

Alakangas, E.

1992-01-01

Optimiturve research program is one of the energy research programs funded by the Ministry of Trade and Industry of Finland. The main target of the program is double the annual hectare yield of peat dried by solar radiation to decrease the peat production costs, to speed up the circulation of capital invested to peat production with the aid of a new production method developed in this research, and hence improve the price competitivity of peat. The targets of the research program are expected to be completed by improving the drying of peat, the efficiency of the peat production machinery, and by developing peat production techniques. The program was started in 1988, and the targets are to be fulfilled up to year 1993. The research program is carried out in cooperation with universities, research organizations and peat producers. This publication consists of the results of the ongoing projects in the Optimiturve research program in 1991. The aim, the contents and the main results of the 18 projects are presented. At the end of this publication there is a list of the reports published in Reports series

Coupled Modeling of Groundwater Flow and Land Subsidence with Secular Strain (Creep)

Science.gov (United States)

Bakr, M.

2012-12-01

Land subsidence limits sustainable development of many areas around the world. This is especially the case in low lying regions such as deltas which accommodate a significant percentage of the human population. Among the most common human-induced factors for land subsidence, is groundwater extractions. In these cases, groundwater flow and land subsidence are coupled processes, especially in basins with extensive spatial extent of soft soils (e.g. clay, peat). Creep (or secondary consolidation) is a land subsidence component that usually contributes to total land subsidence in soft soils. It leads to a reduction in void ratio at constant effective stress, and consequently, to the development of an apparent pre-consolidation pressure. The creep component has been usually ignored in the analysis of coupled groundwater flow and land subsidence. Here, the focus is the development of a coupled model of groundwater flow and land subsidence in porous media considering secular strain (creep). The Bjerrum method for settlement calculation (Bjerrum, 1967) due to change in effective stresses is coupled with MODFLOW to tackle the problem. In particular, the SUB-WT package of MODFLOW (Leake and Galloway, 2007) is modified where the Bjerrum method is used to calculate the primary and secondary consolidation due to change in effective stresses as a result of groundwater abstraction. The Bjerrum model is based on linear strains relationship. Usage of linear strains means that the model directly supports the common parameters Cr, Cc, Cα (i.e. re-compression, compression, and secondary compression indices; respectively). The Bjerrum model assumes that creep rate will reduce with increasing over-consolidation and that over-consolidation will grow by unloading and by ageing. To verify the coupled model, a hypothetical problem is considered where a simple hydrogeological system consisting of a shallow unconfined aquifer and a deeper confined aquifer separated by a (semi

Subsidence above in situ vitrification: Evaluation for Hanford applications

International Nuclear Information System (INIS)

Dershowitz, W.S.; Plum, R.L.; Luey, J.

1995-08-01

Pacific Northwest Laboratory (PNL)is evaluating methods to extend the applicability of the in situ vitrification (ISV) process. One method being evaluated is the initiation of the ISV process in the soil subsurface rather than the traditional start from the surface. The subsurface initiation approach will permit extension of the ISV treatment depth beyond that currently demonstrated and allow selective treatment of contamination in a geologic formation. A potential issue associated with the initiation of the ISV process in the soil subsurface is the degree of subsidence and its effect on the ISV process. The reduction in soil porosity caused by the vitrification process will result in a volume decrease for the vitrified soils. Typical volume reduction observed for ISV melts initiated at the surface are on the order of 20% to 30% of the melt thickness. Movement of in-situ materials into the void space created during an ISV application in the soil subsurface could result in surface settlements that affect the ISV process and the processing equipment. Golder Associates, Inc., of Redmond, Washington investigated the potential for subsidence events during application of ISV in the soil subsurface. Prediction of soil subsidence above an ISV melt required the following analyses: the effect of porosity reduction during ISV, failure of fused materials surrounding the ISV melt, bulking of disturbed materials above the melt, and propagation of strains to the surface

Detecting, mapping and monitoring of land subsidence in Jharia ...

Indian Academy of Sciences (India)

mitigation management of subsidence induced hazards. 1. Introduction ... rural areas with agricultural practices (Cao et al. 2008) ... wall mining, depillaring and caving), water log- ging of the .... accuracy trajectory determination system and the.

Subsidence analysis Forsmark nuclear power plant - unit 1

International Nuclear Information System (INIS)

Bono, Nancy; Fredriksson, Anders; Maersk Hansen, Lars

2010-12-01

On behalf of SKB, Golder Associates Ltd carried out a risk analysis of subsidence during Forsmark nuclear power plant in the construction of the final repository for spent nuclear fuel near and below existing reactors. Specifically, the effect of horizontal cracks have been studied

Identification of Transportation Infrastructure at Risk Due To Sea-Level Rise and Subsidence of Land In Coastal Louisiana

Science.gov (United States)

Tewari, S.; Palmer, W.; Manning, F.

2017-12-01

Climate change can affect coastal areas in a variety of ways. Coasts are sensitive to sea level rise, changes in the frequency/intensity of storms, increase in precipitation and storm surges. The resilience of transportation infrastructure located in Louisiana's coastal zone, against storm surges and climatic sea-level rise is critical. The net change in sea-level is affected by the increase in global sea level as well as land movement up or down. There are many places in coastal Louisiana that have a high subsidence rate. The subsidence could be related to excess extraction activities of oil and water, natural and/or human induced compaction, and tectonic movement. Where the land is sinking, the rate of relative sea level rise is larger than the global rate. Some of the fastest rates of relative sea level rise in the United States are occurring in areas where the land is sinking, including parts of the Gulf Coast. For example, coastal Louisiana has seen its relative sea level rise by eight inches or more in the last 50 years, which is about twice the global rate. Subsiding land in the Gulf area worsens the effects of relative sea level rise, increasing the risk of flooding in cities, inhabited islands, and tidal wetlands. The research team is investigating the trends for sea-level rise and land subsidence in coastal region of Louisiana. The variability in storm surges and its potential implication on the transportation infrastructure in the region is the focus of the study. The spatial maps will be created for spatial trends. This is extremely useful in being prepared for long-term natural hazards. The results of this study will be helpful to LADOTD and infrastructure managers and officials who are tasked with resiliency planning and management. Research results will also directly benefit university researchers in the state, Coastal Protection and Restoration Authority and LADOTD/LTRC through collaborative activity which will educate both professionals and the

Subsidence and Fault Displacement Along the Long Point Fault Derived from Continuous GPS Observations (2012-2017)

Science.gov (United States)

Tsibanos, V.; Wang, G.

2017-12-01

The Long Point Fault located in Houston Texas is a complex system of normal faults which causes significant damage to urban infrastructure on both private and public property. This case study focuses on the 20-km long fault using high accuracy continuously operating global positioning satellite (GPS) stations to delineate fault movement over five years (2012 - 2017). The Long Point Fault is the longest active fault in the greater Houston area that damages roads, buried pipes, concrete structures and buildings and creates a financial burden for the city of Houston and the residents who live in close vicinity to the fault trace. In order to monitor fault displacement along the surface 11 permanent and continuously operating GPS stations were installed 6 on the hanging wall and 5 on the footwall. This study is an overview of the GPS observations from 2013 to 2017. GPS positions were processed with both relative (double differencing) and absolute Precise Point Positioning (PPP) techniques. The PPP solutions that are referred to IGS08 reference frame were transformed to the Stable Houston Reference Frame (SHRF16). Our results show no considerable horizontal displacements across the fault, but do show uneven vertical displacement attributed to regional subsidence in the range of (5 - 10 mm/yr). This subsidence can be associated to compaction of silty clays in the Chicot and Evangeline aquifers whose water depths are approximately 50m and 80m below the land surface (bls). These levels are below the regional pre-consolidation head that is about 30 to 40m bls. Recent research indicates subsidence will continue to occur until the aquifer levels reach the pre-consolidation head. With further GPS observations both the Long Point Fault and regional land subsidence can be monitored providing important geological data to the Houston community.

A Simple Model to Describe the Relationship among Rainfall, Groundwater and Land Subsidence under a Heterogeneous Aquifer

Science.gov (United States)

Zheng, Y. Y.; Chen, Y. L.; Lin, H. R.; Huang, S. Y.; Yeh, T. C. J.; Wen, J. C.

2017-12-01

Land subsidence is a very serious problem of Zhuoshui River alluvial fan, Taiwan. The main reason of land subsidence is a compression of soil, but the compression measured in the wide area is very extensive (Maryam et al., 2013; Linlin et al., 2014). Chen et al. [2010] studied the linear relationship between groundwater level and subsurface altitude variations from Global Positioning System (GPS) station in Zhuoshui River alluvial fan. But the subsurface altitude data were only from two GPS stations. Their distributions are spared and small, not enough to express the altitude variations of Zhuoshui River alluvial fan. Hung et al. [2011] used Interferometry Synthetic Aperture Radar (InSAR) to measure the surface subsidence in Zhuoshui River alluvial fan, but haven't compared with groundwater level. The study compares the correlation between rainfall events and groundwater level and compares the correlation between groundwater level and subsurface altitude, these two correlation affected by heterogeneous soil. From these relationships, a numerical model is built to simulate the land subsidence variations and estimate the coefficient of aquifer soil compressibility. Finally, the model can estimate the long-term land subsidence. Keywords: Land Subsidence, InSAR, Groundwater Level, Numerical Model, Correlation Analyses

Inventory of karst subsidence in the Valley and Ridge Province of East Tennessee

International Nuclear Information System (INIS)

Ketelle, R.H.; Newton, J.G.

1986-01-01

The first regional inventory of karst activity in the Valley and Ridge Province of East Tennessee was performed as a part of ongoing studies at Oak Ridge National Laboratory pertaining to environmental impact assessment of waste disposal in karst settings. More than half the land area in the Valley and Ridge Province of East Tennessee is underlain by karst-prone carbonate bedrock. The regional karst inventory was initiated to obtain current information on the extent of active karst subsidence in the region for use in decision making by the Department of Energy in planning future waste disposal facilities at Oak Ridge, Tennessee. The inventory was performed by contacting personnel of federal, state, and county agencies to obtain reports of known active karst subsidence within the region. Data from these interviews were tabulated resulting in identificaton of more than 250 karst subsidence incidents in East Tennessee, most of which have occurred since 1980. Although the infomation obtained was largely anecdotal, approximate location, date, size, and circumstances under which the collapses occurred were recorded for as many cases as could be documented. The study also included detailed reconnaissance of selected areas similar in geology and hydrology to a study area at Oak Ridge, Tennessee to identify causative factors which contribute to karst subsidence in the region and for comparison of the occurrence of visible karst features at different sites. Human activities affecting site hydrology such as large scale land clearing and earthmoving projects were related to most of the subsidence incidents inventoried

Overview of Gas Research Institute environmental research programs

International Nuclear Information System (INIS)

Evans, J.M.

1991-01-01

The Gas Research Institute (GRI) is a private not-for-profit membership organization of natural gas pipelines, distribution companies and natural gas producers. GRI's purpose is to plan, to manage and to develop financing for a gas-related research and development (R and D) program on behalf of its members and their customers. GRI does not do any research itself. GRI's R and D program is designed to provide advanced technologies for natural gas supply, transport, storage, distribution and end-use applications in all markets. In addition, basic research is conducted for GRI in these areas to build a foundation for future technology breakthroughs. Work in the Environment and Safety Research Department includes sections interested in: supply related research, air quality research, end use equipment safety research, gas operations safety research, and gas operations environmental research. The Natural Gas Supply Program has research ongoing in such areas as: restoration of pipeline right-of-ways; cleaning up town gas manufacturing sites; the development of methanogenic bacteria for soil and groundwater cleanup; development of biological fluidized carbon units for rapid destruction of carbonaceous compounds; research on liquid redox sulfur recovery for sulfur removal from natural gas; research on produced water and production wastes generated by the natural gas industry; environmental effects of coalbed methane production; and subsurface effects of natural gas operations. The western coalbed methane and ground water programs are described

InSAR Time Series Analysis of Natural and Anthropogenic Coastal Plain Subsidence: The Case of Sibari (Southern Italy

Directory of Open Access Journals (Sweden)

Giuseppe Cianflone

2015-11-01

Full Text Available We applied the Small Baseline Subset multi-temporal InSAR technique (SBAS to two SAR datasets acquired from 2003 up to 2013 by Envisat (ESA, European Space Agency and COSMO-SkyMed (ASI, Italian Space Agency satellites to investigate spatial and temporal patterns of land subsidence in the Sibari Plain (Southern Italy. Subsidence processes (up to ~20 mm/yr were investigated comparing geological, hydrogeological, and land use information with interferometric results. We suppose a correlation between subsidence and thickness of the Plio-Quaternary succession suggesting an active role of the isostatic compensation. Furthermore, the active back thrusting in the Corigliano Gulf could trigger a flexural subsidence mechanism even if fault activity and earthquakes do not seem play a role in the present subsidence. In this context, the compaction of Holocene deposits contributes to ground deformation. Despite the rapid urbanization of the area in the last 50 years, we do not consider the intensive groundwater pumping and related water table drop as the main triggering cause of subsidence phenomena, in disagreement with some previous publications. Our interpretation for the deformation fields related to natural and anthropogenic factors would be a comprehensive and exhaustive justification to the complexity of subsidence processes in the Sibari Plain.

Land subsidence susceptibility and hazard mapping: the case of Amyntaio Basin, Greece

Science.gov (United States)

Tzampoglou, P.; Loupasakis, C.

2017-09-01

Landslide susceptibility and hazard mapping has been applying for more than 20 years succeeding the assessment of the landslide risk and the mitigation the phenomena. On the contrary, equivalent maps aiming to study and mitigate land subsidence phenomena caused by the overexploitation of the aquifers are absent from the international literature. The current study focuses at the Amyntaio basin, located in West Macedonia at Florina prefecture. As proved by numerous studies the wider area has been severely affected by the overexploitation of the aquifers, caused by the mining and the agricultural activities. The intensive ground water level drop has triggered extensive land subsidence phenomena, especially at the perimeter of the open pit coal mine operating at the site, causing damages to settlements and infrastructure. The land subsidence susceptibility and risk maps were produced by applying the semi-quantitative WLC (Weighted Linear Combination) method, especially calibrated for this particular catastrophic event. The results were evaluated by using detailed field mapping data referring to the spatial distribution of the surface ruptures caused by the subsidence. The high correlation between the produced maps and the field mapping data, have proved the great value of the maps and of the applied technique on the management and the mitigation of the phenomena. Obviously, these maps can be safely used by decision-making authorities for the future urban safety development.

Numerical Modeling of Mechanical Behavior for Buried Steel Pipelines Crossing Subsidence Strata.

Directory of Open Access Journals (Sweden)

J Zhang

Full Text Available This paper addresses the mechanical behavior of buried steel pipeline crossing subsidence strata. The investigation is based on numerical simulation of the nonlinear response of the pipeline-soil system through finite element method, considering large strain and displacement, inelastic material behavior of buried pipeline and the surrounding soil, as well as contact and friction on the pipeline-soil interface. Effects of key parameters on the mechanical behavior of buried pipeline were investigated, such as strata subsidence, diameter-thickness ratio, buried depth, internal pressure, friction coefficient and soil properties. The results show that the maximum strain appears on the outer transition subsidence section of the pipeline, and its cross section is concave shaped. With the increasing of strata subsidence and diameter-thickness ratio, the out of roundness, longitudinal strain and equivalent plastic strain increase gradually. With the buried depth increasing, the deflection, out of roundness and strain of the pipeline decrease. Internal pressure and friction coefficient have little effect on the deflection of buried pipeline. Out of roundness is reduced and the strain is increased gradually with the increasing of internal pressure. The physical properties of soil have a great influence on the mechanical properties of buried pipeline. The results from the present study can be used for the development of optimization design and preventive maintenance for buried steel pipelines.

Advancing Coastal Climate Adaptation in Denmark by Land Subsidence Mapping using Sentinel-1 Satellite Imagery

DEFF Research Database (Denmark)

Sørensen, Carlo Sass; Broge, Niels H.; Mølgaard, Mads R.

2016-01-01

There are still large uncertainties in projections of climate change and sea level rise. Here, land subsidence is an additional factor that may adversely affect the vulnerability towards floods in low-lying coastal communities. The presented study performs an initial assessment of subsidence...

Large networks of artificial radar reflectors to monitor land subsidence in natural lowlying coastal areas

Science.gov (United States)

Tosi, Luigi; Strozzi, Tazio; Teatini, Pietro

2014-05-01

intensity of the surrounding area; (ii) the network must be established resembling a sort of levelling benchmark network, i.e. with the TCRs placed keeping to a value of about 1.0-1.5 km the maximum distance between the TCRs or between an 'artificial' and the adjacent 'natural' reflectors to reliably resolve the radar phase ambiguities in the presence of atmospheric artifacts. Moreover, our experiment provided new information in order to improve the knowledge of the regional and local processes acting in the Venice Lagoon. We found that the northern basin of the lagoon is subsiding at a rate of about 3-4 mm/yr, while the central and the southern lagoon regions are more stable. At the local scale, i.e., the scale of the single salt marshes, significant differences have been detected depending, for example, on the nature and the architecture of Holocene deposits (Tosi et al., 2009). Acknowledgments. This work was supported by Magistrato alle Acque di Venezia-Venice Water Authority (VWA) and Consorzio Venezia Nuova (CVN) through the INLET Project and partially developed within the RITMARE Flagship Project (CNR-MIUR), Action 2 (SP3-WP1). TERRASAR-X data courtesy COA0612, © DLR. References. Teatini, P., Tosi, L., Strozzi, T., Carbognin, L., Cecconi, G., Rosselli, R., & Libardo, S. (2012). Resolving land subsidence within the venice lagoon by persistent scatterer SAR interferometry. Physics and Chemistry of the Earth, 40-41, 72-79, doi: 10.1016/j.pce.2010.01.002. Strozzi, T., Teatini, P., Tosi, L., Wegmüller, U., & Werner, C. (2013). Land subsidence of natural transitional environments by satellite radar interferometry on artificial reflectors. Journal of Geophysical Research F: Earth Surface, 118(2), 1177-1191, doi: 10.1002/jgrf.2008. Tosi, L., Rizzetto, F., Zecchin, M., Brancolini, G., & Baradello, L. (2009). Morphostratigraphic framework of the venice lagoon (italy) by very shallow water VHRS surveys: Evidence of radical changes triggered by human-induced river diversions

Calibration of a Land Subsidence Model Using InSAR Data via the Ensemble Kalman Filter.

Science.gov (United States)

Li, Liangping; Zhang, Meijing; Katzenstein, Kurt

2017-11-01

The application of interferometric synthetic aperture radar (InSAR) has been increasingly used to improve capabilities to model land subsidence in hydrogeologic studies. A number of investigations over the last decade show how spatially detailed time-lapse images of ground displacements could be utilized to advance our understanding for better predictions. In this work, we use simulated land subsidences as observed measurements, mimicking InSAR data to inversely infer inelastic specific storage in a stochastic framework. The inelastic specific storage is assumed as a random variable and modeled using a geostatistical method such that the detailed variations in space could be represented and also that the uncertainties of both characterization of specific storage and prediction of land subsidence can be assessed. The ensemble Kalman filter (EnKF), a real-time data assimilation algorithm, is used to inversely calibrate a land subsidence model by matching simulated subsidences with InSAR data. The performance of the EnKF is demonstrated in a synthetic example in which simulated surface deformations using a reference field are assumed as InSAR data for inverse modeling. The results indicate: (1) the EnKF can be used successfully to calibrate a land subsidence model with InSAR data; the estimation of inelastic specific storage is improved, and uncertainty of prediction is reduced, when all the data are accounted for; and (2) if the same ensemble is used to estimate Kalman gain, the analysis errors could cause filter divergence; thus, it is essential to include localization in the EnKF for InSAR data assimilation. © 2017, National Ground Water Association.

Land subsidence along the Delta-Mendota Canal in the northern part of the San Joaquin Valley, California, 2003-10

Science.gov (United States)

Sneed, Michelle; Brandt, Justin; Solt, Mike

2013-01-01

Extensive groundwater withdrawal from the unconsolidated deposits in the San Joaquin Valley caused widespread aquifer-system compaction and resultant land subsidence from 1926 to 1970—locally exceeding 8.5 meters. The importation of surface water beginning in the early 1950s through the Delta-Mendota Canal and in the early 1970s through the California Aqueduct resulted in decreased pumping, initiation of water-level recovery, and a reduced rate of compaction in some areas of the San Joaquin Valley. However, drought conditions during 1976–77 and 1987–92, and drought conditions and regulatory reductions in surface-water deliveries during 2007–10, decreased surface-water availability, causing pumping to increase, water levels to decline, and renewed compaction. Land subsidence from this compaction has reduced freeboard and flow capacity of the Delta-Mendota Canal, the California Aqueduct, and other canals that deliver irrigation water and transport floodwater. The U.S. Geological Survey, in cooperation with the U.S. Bureau of Reclamation and the San Luis and Delta-Mendota Water Authority, assessed land subsidence in the vicinity of the Delta-Mendota Canal as part of an effort to minimize future subsidence-related damages to the canal. The location, magnitude, and stress regime of land-surface deformation during 2003–10 were determined by using extensometer, Global Positioning System (GPS), Interferometric Synthetic Aperture Radar (InSAR), spirit leveling, and groundwater-level data. Comparison of continuous GPS, shallow extensometer, and groundwater-level data, combined with results from a one-dimensional model, indicated the vast majority of the compaction took place beneath the Corcoran Clay, the primary regional confining unit. Land-surface deformation measurements indicated that much of the northern portion of the Delta-Mendota Canal (Clifton Court Forebay to Check 14) was fairly stable or minimally subsiding on an annual basis; some areas showed

A Procedure to Map Subsidence at the Regional Scale Using the Persistent Scatterer Interferometry (PSI Technique

Directory of Open Access Journals (Sweden)

Ascanio Rosi

2014-10-01

Full Text Available In this paper, we present a procedure to map subsidence at the regional scale by means of persistent scatterer interferometry (PSI. Subsidence analysis is usually restricted to plain areas and where the presence of this phenomenon is already known. The proposed procedure allows a fast identification of subsidences in large and hilly-mountainous areas. The test area is the Tuscany region, in Central Italy, where several areas are affected by natural and anthropogenic subsidence and where PSI data acquired by the Envisat satellite are available both in ascending and descending orbit. The procedure consists of the definition of the vertical and horizontal components of the deformation measured by satellite at first, then of the calculation of the “real” displacement direction, so that mainly vertical deformations can be individuated and mapped.

Determination of Soft Lithology Causes The Land Subsidence in Coastal Semarang City by Resistivity Methods

Science.gov (United States)

Widada, Sugeng; Saputra, Sidhi; Hariadi

2018-02-01

Semarang City is located in the northern coastal plain of Java which is geologically composed of alluvial deposits. The process of the sediment diagenesis has caused a land subsidence. On the other hand, the development of the industrial, service, education and housing sectors has increased the number of building significantly. The number of building makes the pressure of land surface increased, and finally, this also increased the rate of land subsidence. The drilling data indicates that not all layers of lithology are soft layers supporting the land subsidence. However, vertical distribution of the soft layer is still unclear. This study used Resistivity method to map out the soft zone layers of lithology. Schlumberger electrode configuration with sounding system method was selected to find a good vertical resolution and maximum depth. The results showed that the lithology layer with resistivity less than 3 ohm is a layer of clay and sandy clay that has the low bearing capacity so easily compressed by pressure load. A high land subsidence is happening in the thick soft layer. The thickness of that layer is smaller toward the direction of avoiding the beach. The improvement of the bearing capacity of this layer is expected to be a solution to the problem of land subsidence.

Do increases in subsidized housing reduce the incidence of homelessness? Vidence from the low-income housing tax credit

OpenAIRE

Jackson, Osborne; Kawano, Laura

2015-01-01

We examine the impact of subsidized housing on homelessness using the Low-Income Housing Tax Credit (LIHTC), the largest place-based housing program in the United States. To generate quasi-experimental variation in housing placements, we exploit a discontinuous increase in the amount of tax credits available to projects placed in certain high-poverty neighborhoods. Using data from the U.S. Census and HUD, we find that LIHTC project installation has no significant impact on neighborhood homele...

Long-Run Effects of Public-Private Research Joint Ventures:

DEFF Research Database (Denmark)

Kaiser, Ulrich; Kuhn, Johan Moritz

Subsidized research joint ventures (RJVs) between public research institutions and industry have become increasingly popular in Europe and the US. We study the long-run effects of such a support scheme that has been maintained by the Danish government since 1995. To cope with identification...... problems we apply nearest neighbor caliper matching and conditional difference-in-difference estimation methods. Our main findings are that (i) program participation effects are instant for annual patent applications and last for three years, (ii) employment effects materialize first after one year...

Gas Research Institute research program summary: Goals and accomplishments

International Nuclear Information System (INIS)

1991-07-01

Gas Research Institute's research and development programs pursue technologies that maximize the value of gas energy services while minimizing the cost of supplying and delivering gaseous fuels. Four program areas, Supply Options, End Use, Gas Operations, and Crosscutting Research, are described in the report, together with related project titles and numbers. Also included are summaries of 1990 research results, research collaboration and supported work, and patents and licensing agreements. Glossaries of budget and program terms and of acronyms and abbreviations often used in the GRI literature are added

Characterization of the multi-component driving land subsidence using Persistent Scatterer Interferometry technique: the Ravenna case of study (Italy)

Science.gov (United States)

Bonì, Roberta; Fiaschi, Simone; Calcaterra, Domenico; Di Martire, Diego; Ibrahim, Ahmed; Meisina, Claudia; Perini, Luisa; Ramondini, Massimo; Tessitore, Serena; Floris, Mario

2015-04-01

Land subsidence represents a kind of hazard, which affects an increasing number of worldwide regions, densely populated, causing damage to the environment and infrastructures. Settlements can be related to multiple processes both natural and anthropic (i.e. vadose zone processes, soil consolidation, aquifer compaction, solid and fluid extraction and load-induced compaction) which take place at different spatio-temporal scale. Over the last decades, advanced subsidence studies exploited Synthetic-Aperture Radar (SAR) data, a recent remote sensing tool, to investigate land subsidence phenomena around the world. In particular, Persistent Scatterer Interferometry (PSI) technique, allowing a quantitative estimation at high resolution of the surface deformations, has already been successfully applied to monitor the phenomenon evolution; PSI measurements represent the cumulative displacement, deriving from the contribution of natural and anthropic components, both superficial and deep. The overlapping of several causative factors makes more difficult to accurately interpret the resulting deformations; therefore, it is essential to implement a suitable methodology to distinguish the shallow and deep components of motion. The aim of our research is to introduce a PSI-based approach not only to monitoring but also to understand the land subsidence mechanism, in order to disentangle the natural and anthropic components of motion. The methodology consists of three main phases: 1) Post-processing elaborations (i.e. interpolation of the cumulated displacements and isokinetics map implementation); 2) Characterization of the subsidence areas (i.e. subsidence pattern recognition by means of automatic time series classification); 3) Mechanisms recognition (i.e. identification of the predisposing and triggering factors and comparison with lito-technical model of subsoil, and with earth measurements). In this work, the methodology has been applied to the Ravenna area, Italy, using

Coastal subsidence in Oregon, USA during the giant Cascadia earthquake of AD 1700

Science.gov (United States)

Hawkes, A.D.; Horton, B.P.; Nelson, A.R.; Vane, C.H.; Sawai, Y.

2011-01-01

Quantitative estimates of land-level change during the giant AD 1700 Cascadia earthquake along the Oregon coast are inferred from relative sea-level changes reconstructed from fossil foraminiferal assemblages preserved within the stratigraphic record. A transfer function, based upon a regional training set of modern sediment samples from Oregon estuaries, is calibrated to fossil assemblages in sequences of samples across buried peat-mud and peat-sand contacts marking the AD 1700 earthquake. Reconstructions of sample elevations with sample-specific errors estimate the amount of coastal subsidence during the earthquake at six sites along 400 km of coast. The elevation estimates are supported by lithological, carbon isotope, and faunal tidal zonation data. Coseismic subsidence at Nehalem River, Nestucca River, Salmon River, Alsea Bay, Siuslaw River and South Slough varies between 0.18 m and 0.85 m with errors between 0.18 m and 0.32 m. These subsidence estimates are more precise, consistent, and generally lower than previous semi-quantitative estimates. Following earlier comparisons of semi-quantitative subsidence estimates with elastic dislocation models of megathrust rupture during great earthquakes, our lower estimates for central and northern Oregon are consistent with modeled rates of strain accumulation and amounts of slip on the subduction megathrust, and thus, with a magnitude of 9 for the AD 1700 earthquake.

Evaluation of subsidence hazard in mantled karst setting: a case study from Val d'Orléans (France)

Science.gov (United States)

Perrin, Jérôme; Cartannaz, Charles; Noury, Gildas; Vanoudheusden, Emilie

2015-04-01

Soil subsidence/collapse is a major geohazard occurring in karst region. It occurs as suffosion or dropout sinkholes developing in the soft cover. Less frequently it corresponds to a breakdown of karst void ceiling (i.e., collapse sinkhole). This hazard can cause significant engineering challenges. Therefore decision-makers require the elaboration of methodologies for reliable predictions of such hazards (e.g., karst subsidence susceptibility and hazards maps, early-warning monitoring systems). A methodological framework was developed to evaluate relevant conditioning factors favouring subsidence (Perrin et al. submitted) and then to combine these factors to produce karst subsidence susceptibility maps. This approach was applied to a mantled karst area south of Paris (Val d'Orléans). Results show the significant roles of the overburden lithology (presence/absence of low-permeability layer) and of the karst aquifer piezometric surface position within the overburden. In parallel, an experimental site has been setup to improve the understanding of key processes leading to subsidence/collapse and includes piezometers for measurements of water levels and physico-chemical parameters in both the alluvial and karst aquifers as well as surface deformation monitoring. Results should help in designing monitoring systems to anticipate occurrence of subsidence/collapse. Perrin J., Cartannaz C., Noury G., Vanoudheusden E. 2015. A multicriteria approach to karst subsidence hazard mapping supported by Weights-of-Evidence analysis. Submitted to Engineering Geology.

Fusion research program in Korea

International Nuclear Information System (INIS)

Hwang, Y.S.

1996-01-01

Fusion research in Korea is still premature, but it is a fast growing program. Groups in several universities and research institutes were working either in small experiments or in theoretical areas. Recently, couple of institutes who have small fusion-related experiments, proposed medium-size tokamak programs to jump into fusion research at the level of international recognition. Last year, Korean government finally approved to construct 'Superconducting Tokamak' as a national fusion program, and industries such as Korea Electric Power Corp. (KEPCO) and Samsung joined to support this program. Korea Basic Science Institute (KBSI) has organized national project teams including universities, research institutes and companies. National project teams are performing design works since this March. (author)

DInSAR-Based Detection of Land Subsidence and Correlation with Groundwater Depletion in Konya Plain, Turkey

Directory of Open Access Journals (Sweden)

Fabiana Caló

2017-01-01

Full Text Available In areas where groundwater overexploitation occurs, land subsidence triggered by aquifer compaction is observed, resulting in high socio-economic impacts for the affected communities. In this paper, we focus on the Konya region, one of the leading economic centers in the agricultural and industrial sectors in Turkey. We present a multi-source data approach aimed at investigating the complex and fragile environment of this area which is heavily affected by groundwater drawdown and ground subsidence. In particular, in order to analyze the spatial and temporal pattern of the subsidence process we use the Small BAseline Subset DInSAR technique to process two datasets of ENVISAT SAR images spanning the 2002–2010 period. The produced ground deformation maps and associated time-series allow us to detect a wide land subsidence extending for about 1200 km2 and measure vertical displacements reaching up to 10 cm in the observed time interval. DInSAR results, complemented with climatic, stratigraphic and piezometric data as well as with land-cover changes information, allow us to give more insights on the impact of climate changes and human activities on groundwater resources depletion and land subsidence.

A proposal to assess the settlement and subsidence behaviour of noncohesive soils after wetting

International Nuclear Information System (INIS)

Hellweg, V.

1981-01-01

On the basis of the causes established for the Elbe-Seitenkanal dyke breach in 1976 - which was due a.o. to the settlement of the uniform fine sand placed-serial ground subsidence investigations according to a test method developed by the author were carried through in high-grade steel cylinders of 35 cm diameter and 70 cm height with three very different noncohesive soils to assess the subsidence behaviour after wetting. Besides a critical evaluation of the so far known methods for assessing ground subsidence and direct comparisons with other authors' results and usual laboratory test results, the processes inside the soil samples placed were carefully observed and analysed with the aid of the large experimental devices used. (orig./MSK) [de

Subsidence rates at the southern Salton Sea consistent with reservoir depletion

Science.gov (United States)

Barbour, Andrew J.; Evans, Eileen; Hickman, Stephen H.; Eneva, Mariana

2016-01-01

Space geodetic measurements from the Envisat satellite between 2003 and 2010 show that subsidence rates near the southeastern shoreline of the Salton Sea in Southern California are up to 52mmyr−1 greater than the far-field background rate. By comparing these measurements with model predictions, we find that this subsidence appears to be dominated by poroelastic contraction associated with ongoing geothermal fluid production, rather than the purely fault-related subsidence proposed previously. Using a simple point source model, we suggest that the source of this proposed volumetric strain is at depths between 1.0 km and 2.4 km (95% confidence interval), comparable to generalized boundaries of the Salton Sea geothermal reservoir. We find that fault slip on two previously imaged tectonic structures, which are part of a larger system of faults in the Brawley Seismic Zone, is not an adequate predictor of surface velocity fields because the magnitudes of the best fitting slip rates are often greater than the full plate boundary rate and at least 2 times greater than characteristic sedimentation rates in this region. Large-scale residual velocity anomalies indicate that spatial patterns predicted by fault slip are incompatible with the observations.

Subsidence rates at the southern Salton Sea consistent with reservoir depletion

Science.gov (United States)

Barbour, Andrew J.; Evans, Eileen L.; Hickman, Stephen H.; Eneva, Mariana

2016-07-01

Space geodetic measurements from the Envisat satellite between 2003 and 2010 show that subsidence rates near the southeastern shoreline of the Salton Sea in Southern California are up to 52mmyr-1 greater than the far-field background rate. By comparing these measurements with model predictions, we find that this subsidence appears to be dominated by poroelastic contraction associated with ongoing geothermal fluid production, rather than the purely fault-related subsidence proposed previously. Using a simple point source model, we suggest that the source of this proposed volumetric strain is at depths between 1.0 km and 2.4 km (95% confidence interval), comparable to generalized boundaries of the Salton Sea geothermal reservoir. We find that fault slip on two previously imaged tectonic structures, which are part of a larger system of faults in the Brawley Seismic Zone, is not an adequate predictor of surface velocity fields because the magnitudes of the best fitting slip rates are often greater than the full plate boundary rate and at least 2 times greater than characteristic sedimentation rates in this region. Large-scale residual velocity anomalies indicate that spatial patterns predicted by fault slip are incompatible with the observations.

Different scale land subsidence and ground fissure monitoring with multiple InSAR techniques over Fenwei basin, China

Directory of Open Access Journals (Sweden)

C. Zhao

2015-11-01

Full Text Available Fenwei basin, China, composed by several sub-basins, has been suffering severe geo-hazards in last 60 years, including large scale land subsidence and small scale ground fissure, which caused serious infrastructure damages and property losses. In this paper, we apply different InSAR techniques with different SAR data to monitor these hazards. Firstly, combined small baseline subset (SBAS InSAR method and persistent scatterers (PS InSAR method is used to multi-track Envisat ASAR data to retrieve the large scale land subsidence covering entire Fenwei basin, from which different land subsidence magnitudes are analyzed of different sub-basins. Secondly, PS-InSAR method is used to monitor the small scale ground fissure deformation in Yuncheng basin, where different spatial deformation gradient can be clearly discovered. Lastly, different track SAR data are contributed to retrieve two-dimensional deformation in both land subsidence and ground fissure region, Xi'an, China, which can be benefitial to explain the occurrence of ground fissure and the correlation between land subsidence and ground fissure.

Coral ages and island subsidence, Hilo drill hole

Science.gov (United States)

Moore, J.G.; Ingram, B.L.; Ludwig, K. R.; Clague, D.A.

1996-01-01

A 25.8-m-thick sedimentary section containing coral fragments occurs directly below a surface lava flow (the ???1340 year old Panaewa lava flow) at the Hilo drill hole. Ten coral samples from this section dated by accelerator mass spectrometry (AMS) radiocarbon and five by thermal infrared multispectral scanner (TIMS) 230Th/U methods show good agreement. The calcareous unit is 9790 years old at the bottom and 1690 years old at the top and was deposited in a shallow lagoon behind an actively growing reef. This sedimentary unit is underlain by a 34-m-thick lava flow which in turn overlies a thin volcaniclastic silt with coral fragments that yield a single 14C date of 10,340 years. The age-depth relations of the dated samples can be compared with proposed eustatic sea level curves after allowance for island subsidence is taken. Island subsidence averages 2.2 mm/yr for the last 47 years based on measurements from a tide gage near the drill hole or 2.5-2.6 mm/yr for the last 500,000 years based on the ages and depths of a series of drowned coral reefs offshore from west Hawaii. The age-depth measurements of coral fragments are more consistent with eustatic sea levels as determined by coral dating at Barbados and Albrolhos Islands than those based on oxygen isotopic data from deep sea cores. The Panaewa lava flow entered a lagoon underlain by coral debris and covered the drill site with 30.9 m of lava of which 11 m was above sea level. This surface has now subsided to 4.2 m above sea level, but it demonstrates how a modern lava flow entering Hilo Bay would not only change the coastline but could extensively modify the offshore shelf.

TerraSAR-X time-series interferometry detects human-induce subsidence in the Historical Centre of Hanoi, Vietnam

Science.gov (United States)

Le, Tuan; Chang, Chung-Pai; Nguyen, Xuan

2016-04-01

Hanoi was the capital of 12 Vietnamese dynasties, where the most historical relics, archaeological ruins and ancient monuments are located over Vietnam. However, those heritage assets are threatened by the land subsidence process occurred in recent decades, which mainly triggered by massive groundwater exploitation and construction activities. In this work, we use a set of high resolution TerraSAR-X images to map small-scale land subsidence patterns in the Historical Centre of Hanoi from April 2012 to November 2013. Images oversampling is integrated into the Small Baseline InSAR processing chain in order to enlarge the monitoring coverage by increasing the point-wise measurements, maintaining the monitoring scale of single building and monument. We analyzed over 2.4 million radar targets on 13.9 km2 area of interest based on 2 main sites: The Citadel, the Old Quarter and French Quarter. The highest subsidence rate recorded is -14.2 mm/year. Most of the heritage assets are considered as stable except the Roman Catholic Archdiocese and the Ceramic Mosaic Mural with the subsidence rates are -14.2 and -13.7 mm/year, respectively. Eventually, optical image and soil properties map are used to determine the causes of subsidence patterns. The result shows the strong relationships between the existing construction sites, the component of sediments and land subsidence processes that occurred in the study site.

Long-Run Effects of Public–Private Research Joint Ventures

DEFF Research Database (Denmark)

Kaiser, Ulrich; Kuhn, Johan Moritz

2012-01-01

Subsidized research joint ventures (RJVs) between public research institutions and industry have become increasingly popular in Europe and the US. We study the long-run effects of such a support scheme that has been maintained by the Danish government since 1995. To cope with identification...... problems we apply nearest neighbor matching and conditional difference-in-difference estimation methods. Our main findings are that (i) program participation effects are instant for annual patent applications and last for three years, (ii) employment effects materialize first after one year and (iii...

Mechanical and geometric controls on the structural evolution of pit crater and caldera subsidence

Science.gov (United States)

Holohan, E. P.; SchöPfer, M. P. J.; Walsh, J. J.

2011-07-01

Pit craters and calderas are volcanic depressions produced by subsidence of a magma reservoir roof. To identify how geometric and mechanical factors may influence the structural evolution of this subsidence, we used two-dimensional distinct element method numerical models. The reservoir host rock was represented as an assemblage of bonded circular particles that interact according to elastic-frictional laws. Varying particle and bond properties produced a range of bulk material properties characteristic of natural rock masses. Fracturing results when bonds break, once their shear or tensile strength is exceeded. The magma reservoir was represented as a region of nonbonded low-friction particles. Withdrawal of magma was simulated by incrementally reducing the area of the reservoir particles. Resultant gravity-driven failure and subsidence of the reservoir roof were explicitly replicated. Interaction of the roof's strength, Young's modulus, thickness/diameter ratio (T/D), and the reservoir's shape yields a variety of model structures and subsidence styles. In conceptual terms, four end-member subsidence styles developed: (1) "central sagging" favored by low strength and low T/D; (2) "central snapping" favored by high strength, low T/D, and a sill-like reservoir shape; (3) "single central block" favored by low to intermediate strength, high Young's modulus, and intermediate T/D; and (4) "multiple central blocks" favored by high strength, low Young's modulus, and high T/D. Most model realizations incorporated some combination of each style, however. The models provide a geomechanical framework for understanding natural pit crater or caldera structures, as at Nindiri (Nicaragua), Fernandina (Galapagos), Dolomieu (La Reunion), and Miyakejima (Japan).

Interferograms showing land subsidence and uplift in Las Vegas Valley, Nevada, 1992-99

Science.gov (United States)

Pavelko, Michael T.; Hoffmann, Jörn; Damar, Nancy A.

2006-01-01

The U.S. Geological Survey, in cooperation with the Nevada Department of Conservation and Natural Resources-Division of Water Resources and the Las Vegas Valley Water District, compiled 44 individual interferograms and 1 stacked interferogram comprising 29 satellite synthetic aperture radar acquisitions of Las Vegas Valley, Nevada, from 1992 to 1999. The interferograms, which depict short-term, seasonal, and long-term trends in land subsidence and uplift, are viewable with an interactive map. The interferograms show that land subsidence and uplift generally occur in localized areas, are responsive to ground-water pumpage and artificial recharge, and, in part, are fault controlled. Information from these interferograms can be used by water and land managers to mitigate land subsidence and associated damage. Land subsidence attributed to ground-water pumpage has been documented in Las Vegas Valley since the 1940s. Damage to roads, buildings, and other engineered structures has been associated with this land subsidence. Land uplift attributed to artificial recharge and reduced pumping has been documented since the 1990s. Measuring these land-surface changes with traditional benchmark and Global Positioning System surveys can be costly and time consuming, and results typically are spatially and temporally sparse. Interferograms are relatively inexpensive and provide temporal and spatial resolutions previously not achievable. The interferograms are viewable with an interactive map. Landsat images from 1993 and 2000 are viewable for frames of reference to locate areas of interest and help determine land use. A stacked interferogram for 1992-99 is viewable to visualize the cumulative vertical displacement for the period represented by the individual interferograms. The interactive map enables users to identify and estimate the magnitude of vertical displacement, visually analyze deformation trends, and view interferograms and Landsat images side by side. The

Structural Analysis for Subsidence of Stacked B-25 Boxes

International Nuclear Information System (INIS)

Jones, W.E.

2003-01-01

The Savannah River Site (SRS) and other U.S. Department of Energy (DOE) sites use shallow land burial facilities (i.e., trenches) to dispose low-level radioactive waste. However, at SRS and other DOE sites, waste containers with up to 90 percent void space are disposed in the shallow land burial facilities. Corrosion and degradation of these containers can result in significant subsidence over time, which can compromise the integrity of the long-term cover. This in turn can lead to increased water infiltration through the long-term cover into the waste and subsequent increased radionuclide transport into the environment. Understanding and predicting shallow-buried, low-level waste subsidence behavior is necessary for evaluating cost-effective and appropriate stabilization required to maintain cover system long-term stability and viability, and to obtain stakeholder acceptance of the long-term implications of waste disposal practices. Two methods (dynamic compaction and static surcharge) have been used at SRS to accelerate waste and container consolidation and reduce potential subsidence prior to long term cover construction. Dynamic compaction comprises repeatedly dropping a heavy (20 ton) weight from about a 40-ft height to consolidate the waste and containers. Static surcharge is the use of a thick (15 ft to 30 ft) soil cover to consolidate the underlying materials over a longer time period (three to six months in this case). Quasi-static modeling of a stack of four B-25 boxes at various stags of corrosion with an applied static surcharge has been conducted and is presented herein

Research Ethics with Undergraduates in Summer Research Training Programs

Science.gov (United States)

Cheung, I.; Yalcin, K.

2016-02-01

Many undergraduate research training programs incorporate research ethics into their programs and some are required. Engaging students in conversations around challenging topics such as conflict of interest, cultural and gender biases, what is science and what is normative science can difficult in newly formed student cohorts. In addition, discussing topics with more distant impacts such as science and policy, intellectual property and authorship, can be difficult for students in their first research experience that have more immediate concerns about plagiarism, data manipulation, and the student/faculty relationship. Oregon State University's Research Experience for Undergraduates (REU) in Ocean Sciences: From Estuaries to the Deep Sea as one model for incorporating a research ethics component into summer undergraduate research training programs. Weaved into the 10-week REU program, undergraduate interns participate in a series of conversations and a faculty mentor panel focused on research ethics. Topics discussed are in a framework for sharing myths, knowledge and personal experiences on issues in research with ethical implications. The series follows guidelines and case studies outlined from the text, On Being A Scientist: Responsible Conduct In Research Committee on Science, Engineering, and Public Policy, National Academy of Sciences.

The Inconvenient Truth of Fresh Sediment: Insights from a New Method for Quantifying Subsidence in the Mississippi Delta

Science.gov (United States)

Chamberlain, E. L.; Shen, Z.; Tornqvist, T. E.; Kim, W.

2017-12-01

Knowing the rates and drivers of subsidence in deltas is essential to coastal management. There is a growing consensus that relatively shallow processes such as compaction and artificial drainage are primary contributors to subsidence, although deeper processes such as faulting may be locally important. Here we present a new method to quantify subsidence of a 6000 km2 relict bayhead delta of the Mississippi Delta, using the depth of the mouthbar-overbank stratigraphic boundary that formed near the low tide level in combination with OSL chronology. The contributions of isostatic processes are removed by subtracting a relative sea-level rise term previously obtained from basal peat. We find that displacement rates of the boundary, averaged over 750 to 1500 years, are on the order of a few mm/yr. Cumulative displacement is strongly correlated to overburden thickness, decreases coastward coincident with thinning of the bayhead delta deposit, and appears unrelated to the thickness of underlying Holocene strata or the occurrence of previously mapped faults. This supports compaction of shallow strata as a dominant driver of subsidence in the Mississippi Delta. We find that at least 50% of elevation gained through overbank deposition is ultimately lost to subsidence, significantly greater than the 35% loss previously estimated for inland localities underlain by peat. Our results demonstrate that bayhead deltas are especially vulnerable to subsidence. This finding has major relevance to coastal restoration in the Mississippi Delta through engineered river-sediment diversions. While inactive regions of the delta may be fairly stable if not perturbed by humans, the introduction of fresh sediment to the delta plain will inevitably accelerate subsidence. Values obtained with our method will be applied to a delta growth model that predicts the land-building potential of river-sediment diversions discharging into open bays under realistic scenarios of load-driven subsidence.

The ground subsidence anomaly investigation around Ambala, India by InSAR and spatial analyses: Why and how the Ambala city behaves as the most significant subsidence region in the Northwest India?

Science.gov (United States)

Kim, J.; Lin, S. Y.; Tsai, Y.; Singh, S.; Singh, T.

2017-12-01

A large ground deformation which may be caused by a significant groundwater depletion of the Northwest India Aquifer has been successfully observed throughout space geodesy techniques (Tsai et al, 2016). Employing advanced time-series ScanSAR InSAR analysis and Gravity Recovery and Climate Experiment (GRACE) satellites data, it revealed 400-km wide huge ground deformation in and around Haryana. It was further notified that the Ambala city located in northern Haryana district shown the most significant ground subsidence with maximum cumulative deformation up to 0.2 meters within 3 years in contrast to the nearby cities such as Patiala and Chandigarh that did not present similar subsidence. In this study, we investigated the details of "Ambala Anomaly" employing advanced time-series InSAR and spatial analyses together with local geology and anthropogenic contexts and tried to identify the factors causing such a highly unique ground deformation pattern. To explore the pattern and trend of Ambala' subsidence, we integrated the time-series deformation results of both ascending L-band PALSAR-1 (Phased Array type L-band Synthetic Aperture Radar) from 2007/1 to 2011/1 and descending C-band ASAR (Advanced Synthetic Aperture Radar) from 2008/9 to 2010/8 to process the 3D decomposition, expecting to reveal the asymmetric movement of the surface. In addition. The spatial analyses incorporating detected ground deformations and local economical/social factors were then applied for the interpretation of "Ambala Anomaly". The detailed interrelationship of driving factors of the "Ambala Anomaly" and the spatial pattern of corresponding ground subsidence will be further demonstrated. After all, we determined the uniqueness of Ambala subsidence possibly be driven by both anthropogenic behaviors including the rapid growth rate of population and constructing of industrial centers as well as the natural geological characteristics and sediment deposition.

The Monitoring and Spatial-Temporal Evolution Characteristic Analysis for Land Subsidence in Beijing

Science.gov (United States)

Zhou, Q.; Zhao, W.; Yu, J.

2018-05-01

At present the land subsidence has been the main geological disaster in the plain area of China, and became one of the most serious disaster that restrict the social and economic sustainable development, it also is an important content in the project of national geographic conditions monitoring. With the development of economy and society, Beijing as the capital of China has experienced significant population growth in the last few decades which led to over-exploitation of the ground water to meet the water demand of more than 20 million inhabitants, especially in the urban region with high population density. However, the rainfall and surface runoff can't satisfy the need of aquifer recharge that product the land subsidence. As China's political center and a metropolis, there are a lot of large constructions, underground traffic projects and complicated municipal pipeline network, and Beijing is also an important traffic hub for national railway and highway network, all of them would be threatened by the land subsidence disaster. In this article the author used twenty ENVISAT Synthetic Aperture Radar (SAR) images acquired in 2008 June-2010 August and ten TerraSAR images acquired in 2011 June-2012 September were processed with Small Baseline Subset SAR Interferometry (SBAS-InSAR) techniques, to investigate spatial and temporal patterns of land subsidence in the urban area of Beijing.

THE MONITORING AND SPATIAL-TEMPORAL EVOLUTION CHARACTERISTIC ANALYSIS FOR LAND SUBSIDENCE IN BEIJING

Directory of Open Access Journals (Sweden)

Q. Zhou

2018-05-01

Full Text Available At present the land subsidence has been the main geological disaster in the plain area of China, and became one of the most serious disaster that restrict the social and economic sustainable development, it also is an important content in the project of national geographic conditions monitoring. With the development of economy and society, Beijing as the capital of China has experienced significant population growth in the last few decades which led to over-exploitation of the ground water to meet the water demand of more than 20 million inhabitants, especially in the urban region with high population density. However, the rainfall and surface runoff can’t satisfy the need of aquifer recharge that product the land subsidence. As China’s political center and a metropolis, there are a lot of large constructions, underground traffic projects and complicated municipal pipeline network, and Beijing is also an important traffic hub for national railway and highway network, all of them would be threatened by the land subsidence disaster. In this article the author used twenty ENVISAT Synthetic Aperture Radar (SAR images acquired in 2008 June–2010 August and ten TerraSAR images acquired in 2011 June–2012 September were processed with Small Baseline Subset SAR Interferometry (SBAS-InSAR techniques, to investigate spatial and temporal patterns of land subsidence in the urban area of Beijing.

Shallow Faulting in Morelia, Mexico, Based on Seismic Tomography and Geodetically Detected Land Subsidence

Science.gov (United States)

Cabral-Cano, E.; Arciniega-Ceballos, A.; Vergara-Huerta, F.; Chaussard, E.; Wdowinski, S.; DeMets, C.; Salazar-Tlaczani, L.

2013-12-01

Subsidence has been a common occurrence in several cities in central Mexico for the past three decades. This process causes substantial damage to the urban infrastructure and housing in several cities and it is a major factor to be considered when planning urban development, land-use zoning and hazard mitigation strategies. Since the early 1980's the city of Morelia in Central Mexico has experienced subsidence associated with groundwater extraction in excess of natural recharge from rainfall. Previous works have focused on the detection and temporal evolution of the subsidence spatial distribution. The most recent InSAR analysis confirms the permanence of previously detected rapidly subsiding areas such as the Rio Grande Meander area and also defines 2 subsidence patches previously undetected in the newly developed suburban sectors west of Morelia at the Fraccionamiento Del Bosque along, south of Hwy. 15 and another patch located north of Morelia along Gabino Castañeda del Rio Ave. Because subsidence-induced, shallow faulting develops at high horizontal strain localization, newly developed a subsidence areas are particularly prone to faulting and fissuring. Shallow faulting increases groundwater vulnerability because it disrupts discharge hydraulic infrastructure and creates a direct path for transport of surface pollutants into the underlying aquifer. Other sectors in Morelia that have been experiencing subsidence for longer time have already developed well defined faults such as La Colina, Central Camionera, Torremolinos and La Paloma faults. Local construction codes in the vicinity of these faults define a very narrow swath along which housing construction is not allowed. In order to better characterize these fault systems and provide better criteria for future municipal construction codes we have surveyed the La Colina and Torremolinos fault systems in the western sector of Morelia using seismic tomographic techniques. Our results indicate that La Colina Fault

Subsidence evaluation in 218-E-E12B, trench 38

International Nuclear Information System (INIS)

Streit, J.J.

1995-01-01

An area in Trench 38 of the 218-E-12B Burial Ground has been gradually sinking over the past few years. The area spans the width of the trench and extends approximately 80 feet down the trench. The depth of the depression is approximately 3 feet in the center and gradually rises to existing grade at the trench edge. It has been determined that the most likely cause of the subsidence is decomposition of buried waste material. Fifty-six percent of the waste buried in the subject area is decomposable and has been in the ground for nine years. Waste packaging is largely plastic lined dump trucks and fiberboard boxes. It is recommended that this area be treated with dynamic compaction to stabilize the waste and minimize the reoccurrence of subsidence in this area

Effects of anthropogenic land-subsidence on river flood hazard: a case study in Ravenna, Italy

Science.gov (United States)

Carisi, Francesca; Domeneghetti, Alessio; Castellarin, Attilio

2015-04-01

Can differential land-subsidence significantly alter the river flooding dynamics, and thus flood risk in flood prone areas? Many studies show how the lowering of the coastal areas is closely related to an increase in the flood-hazard due to more important tidal flooding and see level rise. On the contrary, the literature on the relationship between differential land-subsidence and possible alterations to riverine flood-hazard of inland areas is still sparse, while several areas characterized by significant land-subsidence rates during the second half of the 20th century experienced an intensification in both inundation magnitude and frequency. This study investigates the possible impact of a significant differential ground lowering on flood hazard in proximity of Ravenna, which is one of the oldest Italian cities, former capital of the Western Roman Empire, located a few kilometers from the Adriatic coast and about 60 km south of the Po River delta. The rate of land-subsidence in the area, naturally in the order of a few mm/year, dramatically increased up to 110 mm/year after World War II, primarily due to groundwater pumping and a number of deep onshore and offshore gas production platforms. The subsidence caused in the last century a cumulative drop larger than 1.5 m in the historical center of the city. Starting from these evidences and taking advantage of a recent digital elevation model of 10m resolution, we reconstructed the ground elevation in 1897 for an area of about 65 km2 around the city of Ravenna. We referred to these two digital elevation models (i.e. current topography and topographic reconstruction) and a 2D finite-element numerical model for the simulation of the inundation dynamics associated with several levee failure scenarios along embankment system of the river Montone. For each scenario and digital elevation model, the flood hazard is quantified in terms of water depth, speed and dynamics of the flooding front. The comparison enabled us to

GRI's Devonian Shales Research Program

International Nuclear Information System (INIS)

Guidry, F.K.

1991-01-01

This paper presents a summary of the key observations and conclusions from the Gas Research Institute's (GRI's) Comprehensive Study Well (CSW) research program conducted in the Devonian Shales of the Appalachian Basin. Initiated in 1987, the CSW program was a series of highly instrumented study wells drilled in cooperation with industry partners. Seven wells were drilled as part of the program. Extensive data sets were collected and special experiments were run on the CSW's in addition to the operator's normal operations, with the objectives of identifying geologic production controls, refining formation evaluation tools, and improving reservoir description and stimulation practices in the Devonian Shales. This paper highlights the key results from the research conducted in the CSW program in the areas of geologic production controls, formation evaluation, stimulation and reservoir engineering, and field operations. The development of geologic, log analysis, and reservoir models for the Shales from the data gathered and analysis, and reservoir models for the Shales from the data gathered and analyzed during the research is discussed. In addition, on the basis of what was learned in the CSW program, GRI's plans for new research in the Devonian Shales are described

Improving the influence function method to take topography into the calculation of mining subsidence

OpenAIRE

Cai , Yinfei; Verdel , Thierry; Deck , Olivier; LI , Xiao-Jong

2016-01-01

International audience; The classic influence function method is often used in the calculation of mining subsidence caused by stratiform underground excavations. Theoretically,its use is limited to the subsidence predictions under the condition of horizontal ground surface. In order to improve the original influence function method to take topographic variations into account. Due to real-world mining conditions that are usually complicated, it is difficult to separate topography influences fr...

Human Research Program Integrated Research Plan. Revision A January 2009

Science.gov (United States)

2009-01-01

The Integrated Research Plan (IRP) describes the portfolio of Human Research Program (HRP) research and technology tasks. The IRP is the HRP strategic and tactical plan for research necessary to meet HRP requirements. The need to produce an IRP is established in HRP-47052, Human Research Program - Program Plan, and is under configuration management control of the Human Research Program Control Board (HRPCB). Crew health and performance is critical to successful human exploration beyond low Earth orbit. The Human Research Program (HRP) is essential to enabling extended periods of space exploration because it provides knowledge and tools to mitigate risks to human health and performance. Risks include physiological and behavioral effects from radiation and hypogravity environments, as well as unique challenges in medical support, human factors, and behavioral or psychological factors. The Human Research Program (HRP) delivers human health and performance countermeasures, knowledge, technologies and tools to enable safe, reliable, and productive human space exploration. Without HRP results, NASA will face unknown and unacceptable risks for mission success and post-mission crew health. This Integrated Research Plan (IRP) describes HRP s approach and research activities that are intended to address the needs of human space exploration and serve HRP customers and how they are integrated to provide a risk mitigation tool. The scope of the IRP is limited to the activities that can be conducted with the resources available to the HRP; it does not contain activities that would be performed if additional resources were available. The timescale of human space exploration is envisioned to take many decades. The IRP illustrates the program s research plan through the timescale of early lunar missions of extended duration.

At whose service? Subsidizing services and the skill premium

NARCIS (Netherlands)

van Groezen, Bas; Meijdam, L.

2009-01-01

In this paper we investigate the effects of subsidizing low-skilled, labour-intensive services hired by high-skilled individuals in the presence of labour income taxation. Whether such a subsidy can be Pareto-improving depends crucially on the degree of substitutability of both types of labour in

At Whose Service? Subsidizing Services and the Skill Premium

NARCIS (Netherlands)

van Groezen, B.J.A.M.; Meijdam, A.C.

2010-01-01

In this paper we investigate the effects of subsidizing low-skilled, labourintensive services hired by high-skilled individuals in the presence of labour income taxation. Whether such a subsidy can be Paretoimproving depends crucially on the degree of substitutability of both types of labour in the

On the use of InSAR technology to assess land subsidence in Jakarta coastal flood plain

Science.gov (United States)

Koudogbo, Fifame; Duro, Javier; Garcia Robles, Javier; Arnaud, Alain; Abidin, Hasanuddin Z.

2014-05-01

Jakarta is the capital of Indonesia and is home to approximately 10 million people on the coast of the Java Sea. It is situated on the northern coastal alluvial plane of Java which shares boundaries with West Java Province in the south and in the east, and with Banten Province in the west. The Capital District of Jakarta (DKI) sits in the lowest lying areas of the basin. Its topography varies, with the northern part just meters above current sea level and lying on a flood plain. Subsequently, this portion of the city frequently floods. The southern part of the city is hilly. Thirteen major rivers flow through Jakarta to the Java Sea. The Ciliwung River is the most significant river and divides the city West to East. In the last three decades, urban growing of Jakarta has been very fast in sectors as industry, trade, transportation, real estate, among others. This exponential development has caused several environmental issues; land subsidence is one of them. Subsidence in Jakarta has been known since the early part of the 20th century. It is mainly due to groundwater extraction, the fast development (construction load), soil natural consolidation and tectonics. Evidence of land subsidence exists through monitoring with GPS, level surveys and InSAR investigations. InSAR states for "Interferometric Synthetic Aperture Radar". Its principle is based on comparing the distance between the satellite and the ground in consecutive satellite passes over the same area on the Earth's surface. Radar satellites images record, with very high precision, the distance travelled by the radar signal that is emitted by the satellite is registered. When this distance is compared through time, InSAR technology can provide highly accurate ground deformation measurements. ALTAMIRA INFORMATION, company specialized in ground motion monitoring, has developed GlobalSARTM, which combines several processing techniques and algorithms based on InSAR technology, to achieve ground motion

Evaluation of vertical and horizontal movements in the subsidence depression near Karviná

Czech Academy of Sciences Publication Activity Database

Doležalová, Hana; Kajzar, Vlastimil; Souček, Kamil; Staš, Lubomír

2010-01-01

Roč. 7, č. 3 (2010), s. 355-361 ISSN 1214-9705. [Czech-Polish Workshop on recent geodynamics of the Sudety Mts. and adjacent areas /10./. Sklarska Poreba, 05.11.2009-07.11.2009] R&D Projects: GA ČR GA105/07/1586; GA ČR GA105/07/0878 Institutional research plan: CEZ:AV0Z30860518 Keywords : subsidence depression * GPS * horizontal shifts Subject RIV: DH - Mining, incl. Coal Mining Impact factor: 0.452, year: 2010 http://www.irsm.cas.cz/?Lang=CZE&Menu=25,29,0,0;&File=Obsah/AGG/Contents/AGGC7_3%28159%2910.htm

Seismic safety margins research program overview

International Nuclear Information System (INIS)

Tokarz, F.J.; Smith, P.D.

1978-01-01

A multiyear seismic research program has been initiated at the Lawrence Livermore Laboratory. This program, the Seismic Safety Margins Research Program (SSMRP) is funded by the U.S. Nuclear Regulatory Commission, Office of Nuclear Regulatory Research. The program is designed to develop a probabilistic systems methodology for determining the seismic safety margins of nuclear power plants. Phase I, extending some 22 months, began in July 1978 at a funding level of approximately $4.3 million. Here we present an overview of the SSMRP. Included are discussions on the program objective, the approach to meet the program goal and objectives, end products, the probabilistic systems methodology, and planned activities for Phase I

KUD SERVICE LEVEL IN FARMER SUBSIDIZE FERTILIZER (Case Study in District Banguntapan Bantul Yogyakarta

Directory of Open Access Journals (Sweden)

Sipri Paramita

2014-01-01

Full Text Available The purpose of the study was to determine: (1 the level of service in the provision of subsidized fertilizer cooperatives of farmers on the timeliness, accuracy number, precision type, right quality, right place and the right price, (2 factors that affect the level of service cooperatives in the procurement of subsidized fertilizer at the farm level. Descriptively and purposive of the 90 samples taken at random, were analyzed with analysis of the test sample Kolmogorov-Smirnov, the proportion of single test, and correlation analysis. Obtained results: (1 service cooperatives in the procurement of subsidized fertilizer at the farm level right time, right quantity, right price, right quality and the right target is good, (2 service cooperatives have an inverse correlation with the presence of other distributors. Other factors not directly affect the effectiveness of the service cooperatives

NASA's computer science research program

Science.gov (United States)

Larsen, R. L.

1983-01-01

Following a major assessment of NASA's computing technology needs, a new program of computer science research has been initiated by the Agency. The program includes work in concurrent processing, management of large scale scientific databases, software engineering, reliable computing, and artificial intelligence. The program is driven by applications requirements in computational fluid dynamics, image processing, sensor data management, real-time mission control and autonomous systems. It consists of university research, in-house NASA research, and NASA's Research Institute for Advanced Computer Science (RIACS) and Institute for Computer Applications in Science and Engineering (ICASE). The overall goal is to provide the technical foundation within NASA to exploit advancing computing technology in aerospace applications.

18 CFR 35.44 - Protections against affiliate cross-subsidization.

Science.gov (United States)

2010-04-01

... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Protections against affiliate cross-subsidization. 35.44 Section 35.44 Conservation of Power and Water Resources FEDERAL ENERGY... electric energy may be made between a franchised public utility with captive customers and a market...

Impact of rock salt creep law choice on subsidence calculations for hydrocarbon reservoirs overlain by evaporite caprocks

NARCIS (Netherlands)

Marketos, G.; Spiers, C.J.; Govers, R.

2016-01-01

Accurate forward modeling of surface subsidence above producing hydrocarbons reservoirs requires an understanding of the mechanisms determining how ground deformation and subsidence evolve. Here we focus entirely on rock salt, which overlies a large number of reservoirs worldwide, and specifically

Research program on regulatory safety research

International Nuclear Information System (INIS)

Mailaender, R.

2010-02-01

This paper elaborated for the Swiss Federal Office of Energy (SFOE) presents the synthesis report for 2009 made by the SFOE's program leader on the research program concerning regulatory nuclear safety research, as co-ordinated by the Swiss Nuclear Safety Inspectorate ENSI. Work carried out in various areas is reviewed, including that done on reactor safety, radiation protection and waste disposal as well as human aspects, organisation and safety culture. Work done concerning materials, pressure vessel integrity, transient analysis, the analysis of serious accidents in light-water reactors, fuel and material behaviour, melt cooling and concrete interaction is presented. OECD data bank topics are discussed. Transport and waste disposal research at the Mont Terri rock laboratory is looked at. Requirements placed on the personnel employed in nuclear power stations are examined and national and international co-operation is reviewed

Subsidence (2004-2009) in and near lakebeds of the Mojave River and Morongo groundwater basins, southwest Mojave Desert, California

Science.gov (United States)

Solt, Mike; Sneed, Michelle

2014-01-01

Subsidence, in the vicinity of dry lakebeds, within the Mojave River and Morongo groundwater basins of the southwest Mojave Desert has been measured by Interferometric Synthetic Aperture Radar (InSAR). The investigation has focused on determining the location, extent, and magnitude of changes in land-surface elevation. In addition, the relation of changes in land-surface elevation to changes in groundwater levels and lithology was explored. This report is the third in a series of reports investigating land-surface elevation changes in the Mojave and Morongo Groundwater Basins, California. The first report, U.S. Geological Survey (USGS) Water-Resources Investigations Report 03-4015 by Sneed and others (2003), describes historical subsidence and groundwater-level changes in the southwest Mojave Desert from 1969 to 1999. The second report, U.S. Geological Survey Water-Resources Investigations Report 07-5097, an online interactive report and map, by Sneed and Brandt (2007), describes subsidence and groundwater-level changes in the southwest Mojave Desert from 1999 to 2004. The purpose of this report is to document an updated assessment of subsidence in these lakebeds and selected neighboring areas from 2004 to 2009 as measured by InSAR methods. In addition, continuous Global Positioning System (GPS)(2005-10), groundwater level (1951-2010), and lithologic data, if available, were used to characterize compaction mechanisms in these areas. The USGS California Water Science Center’s interactive website for the Mojave River and Morongo groundwater basins was created to centralize information pertaining to land subsidence and water levels and to allow readers to access available data and related reports online. An interactive map of land subsidence and water levels in the Mojave River and Morongo groundwater basins displays InSAR interferograms, subsidence areas, subsidence contours, hydrographs, well information, and water-level contours. Background information, including

Monitoring and modeling of sinkhole-related subsidence in west-central Florida mapped from InSAR and surface observations

Science.gov (United States)

Kiflu, H.; Oliver-Cabrera, T.; Robinson, T.; Wdowinski, S.; Kruse, S.

2017-12-01

Sinkholes in Florida cause millions of dollars in damage to infrastructure each year. Methods of early detection of sinkhole-related subsidence are clearly desirable. We have completed two years of monitoring of selected sinkhole-prone areas in west central Florida with XXX data and analysis with XXX algorithms. Filters for selecting targets with high signal-to-noise ratio and subsidence over this time window (XX-2015-XX-2017) are being used to select sites for ground study. A subset of the buildings with InSAR-detected subsidence indicated show clear structural indications of subsidence in the form of cracks in walls and roofs. Comsol Multiphysics models have been developed to describe subsidence at the rates identified from the InSAR analysis (a few mm/year) and on spatial scales observed from surface observations, including structural deformation of buildings and ground penetrating radar images of subsurface deformation (length scales of meters to tens of meters). These models assume cylindrical symmetry and deformation of elastic and poroelastic layers over a growing sphering void.

1974 review of the research program

International Nuclear Information System (INIS)

1975-01-01

The role of the Research Program in Controlled Thermonuclear Research, the activities that are contained within the Research Program, and summaries of the reports prepared by the study groups that analyzed the six activity areas that make up the Research Program are described. The recommendations by an ''Overview Panel'' are given. The recommendations are based on an analysis of the individual study group reports, consultations with CTR staff and field scientists, and on independent review of CTR program plans and needs. In some cases the recommendations of the Overview Panel are identical with study group recommendations and in other cases they are not. Some recommendations by the Overview Panel take into account factors and information that go beyond that available to the study groups. The five-year budget needed to accomplish the recommended Research Program is discussed. The Overview Panel chose to normalize its budget recommendations to the actual FY 1975 Research Program budget, reflecting the fact that this is already determined. The budgets for subsequent years are then based on this starting point. The complete reports prepared by the six study groups are given. Each report is based on an analysis of the needs as dictated by the Magnetic Confinement Systems and Development and Technology Program Plans. (U.S.)

Lifting and protecting residential structures from subsidence damage using airbags

International Nuclear Information System (INIS)

Triplett, T.L.; Bennett, R.M.

1998-01-01

Conventional practice in protecting residential structures from subsidence damage concentrates on saving the superstructure. The foundation is sacrificed, even though it represents the structural component with the greatest replacement cost. In this study, airbags were used to lift a 20 ft x 30 ft structure to test their ability to protect both the foundation and superstructure from ground settlement. Two contiguous sides of the test foundation were unreinforced, and the other two contiguous sides incorporated footing and wall reinforcement. The airbags successfully lifted the structure without causing damage, even on the unreinforced sides. This paper gives a procedure for determining airbag spacing, and describes installation and operation techniques of the airbags. The paper then focuses on the performance of the airbags in lifting the structure, and shows that airbags can preserve existing foundations during subsidence movements

75 FR 54885 - Submission for OMB Review; Comment Request

Science.gov (United States)

2010-09-09

... Researchers, Policy Experts, and State- level Coordinators Discussion Guide for Use with Program 25 1 2.5 63... subsidized and transitional employment programs. Through this information collection and other study....g. state-level coordinators), subsidized and transitional employment program directors and staffs...

NCI: DCTD: Biometric Research Program

Science.gov (United States)

The Biometric Research Program (BRP) is the statistical and biomathematical component of the Division of Cancer Treatment, Diagnosis and Centers (DCTDC). Its members provide statistical leadership for the national and international research programs of the division in developmental therapeutics, developmental diagnostics, diagnostic imaging and clinical trials.

The Use of the Internet to Support General Aviation Research

Science.gov (United States)

Rowbottom, James H.

1995-01-01

For the past few years, innovation in the field of General Aviation (GA) has declined. The reason for this decline has not been because of a lack of ideas, but rather a lack of funds necessary to convert these ideas into reality. NASA implemented the Small Business Innovative Research (SBIR) program in an effort to promote new technology in General Aviation. Under this program, small business with good ideas present them to NASA who reviews them and determines their value potential in the GA market. If the company's idea proves worthy, NASA subsidizes their research in three phases that include the research, testing, development, and production of their product. The purpose of my internship this summer was to use the Internet to promote the work of SBIR companies globally to prospective investors.

The influence of subsidence attributable to coal mining on the environment, development and restoration: some examples from western Europe and South Africa

Energy Technology Data Exchange (ETDEWEB)

Bell, F.G.; Genske, D.D. [University of Natal, Durban (South Africa). Dept. of Geology & Applied Geology

2001-02-01

One of the consequences of coal mining is subsidence, and it is associated with past and present mine workings. Indeed, old abandoned coal mines worked by the room-and-pillar method, which occur at shallow depth, often present a potential hazard as pillars collapse or voids migrate to the surface. Frequently, the situation is compounded by the fact that such workings are unrecorded. Subsidence prediction in such cases is impossible. In longwall mining, the total extraction of panels takes place, the working face being supported, while support is removed from behind the working face allowing the roof to collapse. Subsidence consequent on longwall mining can be regarded as more or less contemporaneous with mining and is normally predictable. This means that it is possible to develop an area after subsidence due to longwall mining has occurred or to incorporate features into the design of buildings and structures that will accommodate ground movements generated by subsidence. The nature of subsidence can be affected by discontinuities in the surface strata or the presence of superficial deposits. Of course, subsidence can adversely affect existing buildings and structures which do not incorporate special design features. In severe cases of subsidence damage, buildings may have to be demolished. Important buildings may be restored. Another problem associated with subsidence is flooding due to notable lowering of the ground surface. Examples of such problems and solutions are highlighted by the examples given.

Measurement of Subsidence in the Yangbajain Geothermal Fields from TerraSAR-X

Science.gov (United States)

Li, Yongsheng; Zhang, Jingfa; Li, Zhenhong

2016-08-01

Yangbajain contains the largest geothermal energy power station in China. Geothermal explorations in Yangbajain first started in 1976, and two plants were subsequently built in 1981 and 1986. A large amount of geothermal fluids have been extracted since then, leading to considerable surface subsidence around the geothermal fields. In this paper, InSAR time series analysis is applied to map the subsidence of the Yangbajain geothermal fields during the period from December 2011 to November 2012 using 16 senses of TerraSAR-X stripmap SAR images. Due to its high resolution and short repeat cycle, TerraSAR-X provides detailed surface deformation information at the Yangbajain geothermal fields.

New information on regional subsidence and soil fracturing in Mexico City Valley

Directory of Open Access Journals (Sweden)

G. Auvinet

2015-11-01

Full Text Available In this paper, updated information about regional subsidence in Mexico City downtown area is presented. Data obtained by R. Gayol in 1891, are compared with information obtained recently from surveys using the reference points of Sistema de Aguas de la Ciudad de México (2008 and on the elevation of a cloud of points on the ground surface determined using Light Detection and Ranging (LiDAR technology. In addition, this paper provides an overview of recent data obtained from systematic studies focused on understanding soil fracturing associated with regional land subsidence and mapping of areas susceptible to cracking in Mexico City Valley.

Fusion Energy Postdoctoral Research Program, Professional Development Program: FY 1987 annual report

International Nuclear Information System (INIS)

1988-01-01

In FY 1986, Oak Ridge Associated Universities (ORAU) initiated two programs for the US Department of Energy (DOE), Office of Fusion Energy (OFE): the Fusion Energy Postdoctoral Research Program and the Fusion Energy Professional Development Program. These programs provide opportunities to conduct collaborative research in magnetic fusion energy research and development programs at DOE laboratories and contractor sites. Participants become trained in advanced fusion energy research, interact with outstanding professionals, and become familiar with energy-related national issues while making personal contributions to the search for solutions to scientific problems. Both programs enhance the national fusion energy research and development effort by providing channels for the exchange of scientists and engineers, the diffusion of ideas and knowledge, and the transfer of relevant technologies. These programs, along with the Magnetic Fusion Energy Science and Technology Fellowship Programs, compose the fusion energy manpower development programs administered by ORAU for DOE/OFE

Residual subsidence analysis after the end of coal mine work. Example from Lorraine Colliery, France

International Nuclear Information System (INIS)

Al Heib, M.; Nicolas, M.; Noirel, J.F.; Wojtkowiak, F.

2005-01-01

This paper describes the residual movements associated with the deep coal mines. The studied case relates to works located into Lorraine coal basin. The paper is divided into two sections. The first one describes subsidence phenomena, especially the residual phase in terms of amplitude, duration and localization. The second one focus on Morsbach case: the total and residual subsidence measurements will be analyzed and compared to the state of the art as well as the currant knowledge. The results of the analysis show that the duration of residual movements does not exceed 24 months and their amplitude is about 5% of total subsidence. We analyze also the declarations of the mining damage during and after the mining period. Damages occur, after this period are probably due to late observations. (authors)

Epidemiology & Genomics Research Program

Science.gov (United States)

The Epidemiology and Genomics Research Program, in the National Cancer Institute's Division of Cancer Control and Population Sciences, funds research in human populations to understand the determinants of cancer occurrence and outcomes.

Assessing the long-term impact of subsidence and global climate change on emergency evacuation routes in coastal Louisiana.

Science.gov (United States)

2012-12-01

Subsidence forecast models for coastal Louisiana were developed to estimate the change in surface elevations of evacuation routes for the years 2015, 2025, 2050, and 2100. Geophysical and anthropogenic subsidence estimates were derived from on-going ...

Study on the change law of soil in subsidence area of horizontal coal seam

Science.gov (United States)

Li, Pengfeng; Wang, Shugang; Liu, Wei

2017-11-01

In order to provide theoretical basis for land reclamation in subsidence area, the mining subsidence area is divided into three areas: zone I (stretching zone), zone II (compression zone) and zone III (neutral zone). On this basis, the change characteristics of the soil in the three areas of the horizontal coal seam mining subsidence area are studied. The results show that: due to stretching, soil of zone I cracks was developed, the soil continuity damage, poor integrity, serious leakage of soil Water Leakage fertilizer, the area shows the soil water holding capacity decreased, the decline of soil fertility, soil coarsening and barren trend. The soil mass in zone II is compressed and the soil structure is relatively complete, but the soil bulk density increases correspondingly, while the soil porosity decreases gradually and the permeability decreases. The main soil layer in the zone III is vertical deformation, and the soil integrity is better. But the influence of mined out area leads to the movement of water and nutrients to the lower part of the soil. This paper suggests that in the land reclamation process should adopt corresponding reclamation method based on the variation law of the three soil area of reclamation area of mining subsidence, for improving soil physicochemical properties, so as to achieve the purpose of effective reclamation.

Multi-temporal InSAR evidence of ground subsidence induced by groundwater withdrawal: the Montellano aquifer (SW Spain)

NARCIS (Netherlands)

Ruiz-Constán, A.; Ruiz-Armenteros, A.M.; Lamas-Fernández, F.; Martos-Rosillo, S.; Delgado, J.M.; Bekaert, D.P.S.; Sousa, J.J.; Gil, A.J.; Caro Cuenca, M.; Hanssen, R.F.; Galindo-Zaldívar, J.; Sanz de Galdeano, C.

2016-01-01

This study uses the InSAR technique to analyse ground subsidence due to intensive exploitation of an aquifer for agricultural and urban purposes in the Montellano town (SW Spain). The detailed deformation maps clearly show that the spatial and temporal extent of subsidence is controlled by

Long Wavelenth Subsidence of Western Europe during Late Eocene-Oligocene (38-23 Ma): Mantle Dynamic Effect?

Science.gov (United States)

Guillocheau, Francois; Robin, Cécile; Bessin, Paul

2015-04-01

Western Europe (France, southern Britain, southern Belgium, western Germany) is subsiding during Late Eocene to Oligocene (38-23 Ma) as suggested by the growth of numerous small sedimentary basins mainly filled by lacustrine deposits with some brackish to marine deposits. This large-scale subsidence is coeval with the early stage of the so-called Oligocene rifts (in fact Late Bartonian to Rupelian): Lower Rhinegraben, Bresse, Limagnes. The subsiding domain extends from Cornwall to the Rhine Graben including the Armorican Massif, the southern Paris Basin, the northern Aquitaine Basin, the French Central Massif, the Ardennes-Eifel… This subsidence occurred at a period of global sea level fall and then an eustatic component cannot explain (1) the accommodation space creation and (2) the marine floding with a paroxysm during Early Oligocene times (Armorican Massif, ?Ardennes, French Massif central). This marine flooding also indicate that the relief of the Hercynian basement was less elevated and smoother than today. Some of those small "basins" were interpreted as little rifts, but new mapping (e.g. Puy-en-Velay or Forez Plain in the French Massif central) or new geophysical data (e.g. Rennes Basin in the Armorican massif) suggest that no faults control those basins or that they result from post-depositional collapses. This long wavelength subsidence is at the scale of the mantle dynamic. Possible mantle mechanisms and the relationships with the "Oligocene" rifts and the North Sea inversion will be discussed.

Halting Land Subsidence in Tucson, Arizona: Examining the Poroelastic Response to Artificial Recharge

Science.gov (United States)

Miller, M. M.; Shirzaei, M.; Argus, D. F.

2017-12-01

Overexploitation of groundwater results in stressed aquifer systems and surface deformation in the form of land subsidence. Differential land subsidence can lead to earth fissures, which threaten buildings and infrastructure. Therefore, careful water management is necessary to ensure aquifer resources are withdrawn and replenished at a sustainable yield to preserve supplies and minimize surface deformation. Tucson, Arizona is a semi-arid desert city that is reliant on a semi-confined alluvial aquifer system for much of the water supply. To understand the poroelastic response of the aquifer system over time, we analyze data from wells equipped with extensometers, InSAR time series, and GPS. From 1990-2005, compaction of fine-grained, aquitard material is measured up to 8.5 mm/yr at well sites equipped with extensometers. This induces permanent aquifer storage volume losses up to 4.1%. Yet, interferograms from Envisat and RadarSAT-2 C-band satellites, which yield multitemporal deformation maps at high resolution, reveal that subsidence remarkably slows by the late 2000s and nearly halts by 2015. We infer this deceleration corresponds to heightened artificial recharge efforts to bank Colorado River water delivered via canal. After groundwater levels recover, residual compaction continues for just a 6.6-year interval, which suggests a high value for vertical hydraulic conductivity up to 9.8 x10-4 m/day. Successful water management and conservation plans help the city preserve existing and replenish depleted groundwater reserves, decelerate land subsidence, and likely reduce the risks associated with earth fissuring.

Subsidized health insurance coverage of people in the informal sector and vulnerable population groups: trends in institutional design in Asia.

Science.gov (United States)

Vilcu, Ileana; Probst, Lilli; Dorjsuren, Bayarsaikhan; Mathauer, Inke

2016-10-04

Many low- and middle-income countries with a social health insurance system face challenges on their road towards universal health coverage (UHC), especially for people in the informal sector and vulnerable population groups or the informally employed. One way to address this is to subsidize their contributions through general government revenue transfers to the health insurance fund. This paper provides an overview of such health financing arrangements in Asian low- and middle-income countries. The purpose is to assess the institutional design features of government subsidized health insurance type arrangements for vulnerable and informally employed population groups and to explore how these features contribute to UHC progress. This regional study is based on a literature search to collect country information on the specific institutional design features of such subsidization arrangements and data related to UHC progress indicators, i.e. population coverage, financial protection and access to care. The institutional design analysis focuses on eligibility rules, targeting and enrolment procedures; financing arrangements; the pooling architecture; and benefit entitlements. Such financing arrangements currently exist in 8 countries with a total of 14 subsidization schemes. The most frequent groups covered are the poor, older persons and children. Membership in these arrangements is mostly mandatory as is full subsidization. An integrated pool for both the subsidized and the contributors exists in half of the countries, which is one of the most decisive features for equitable access and financial protection. Nonetheless, in most schemes, utilization rates of the subsidized are higher compared to the uninsured, but still lower compared to insured formal sector employees. Total population coverage rates, as well as a higher share of the subsidized in the total insured population are related with broader eligibility criteria. Overall, government subsidized health

Prediction of abrupt reservoir compaction and surface subsidence due to pore collapse in carbonates

Energy Technology Data Exchange (ETDEWEB)

Smits, R.M.M.; de Waal, A.; van Kooten, J.F.C.

1986-01-01

A new procedure has been developed to predict the abrupt in-situ compaction and the associated surface subsidence above high-porosity carbonate fields showing pore collapse. The approach is based on an extensive laboratory compaction study in which the effects of carbonate type, porosity, core preparation, pore saturant, horizontal to vertical stress ratio and loading rate on the pore collapse behaviour were investigated. For each carbonate type a trendline was established describing the relationship between the porosity after collapse and the vertical effective stress. This trendline concept, in combination with existing subsidence models, enables reservoir compaction and surface subsidence to be predicted on the basis of wireline porosity logs. Static and dynamic elastic constants were found to be uncorrelated during pore collapse. The position of the trendline depends strongly on carbonate type, pore saturant, loading rate and stress ratio. Therefore procedures are given to derive the correct in-situ trendline from laboratory compaction experiments.

Prediction of abrupt reservoir compaction and surface subsidence caused by pore collapse in carbonates

Energy Technology Data Exchange (ETDEWEB)

Smits, R.M.M.; De Waal, J.A.; Van Kootan, J.F.C.

1988-06-01

A new procedure has been developed to predict the abrupt in-situ compaction and the associated surface subsidence above high-porosity carbonate fields that show pore collapse. The approach is based on an extensive laboratory compaction study in which the effects of carbonate type, porosity, core preparation, pore saturant, horizontal/vertical stress ratio, and loading rate on pore-collapse behavior were investigated. For a number of carbonate types, a trendline was established that describes the relationship between the porosity after collapse and the vertical effective stress. This trendline concept, in combination with existing subsidence models, enables reservoir compaction and surface subsidence to be predicted on the basis of wireline porosity logs. Static and dynamic elastic constants were found to be uncorrelated during pore collapse. The position of the trendline depends strongly on carbonate type, pore saturant, loading rate, and stress ratio. Therefore, procedures are given to derive the correct in-situ trendline from laboratory compaction experiments.

Post-depositional fracturing and subsidence of pumice flow deposits: Lascar Volcano, Chile.

Science.gov (United States)

Whelley, Patrick L; Jay, J; Calder, E S; Pritchard, M E; Cassidy, N J; Alcaraz, S; Pavez, A

Unconsolidated pyroclastic flow deposits of the 1993 eruption of Lascar Volcano, Chile, have, with time, become increasingly dissected by a network of deeply penetrating fractures. The fracture network comprises orthogonal sets of decimeter-wide linear voids that form a pseudo-polygonal grid visible on the deposit surface. In this work, we combine shallow surface geophysical imaging tools with remote sensing observations and direct field measurements of the deposit to investigate these fractures and their underlying causal mechanisms. Based on ground penetrating radar images, the fractures are observed to have propagated to depths of up to 10 m. In addition, orbiting radar interferometry shows that deposit subsidence of up to 1 cm/year -1 occurred between 1993 and 1996 with continued subsidence occurring at a slower rate thereafter. In situ measurements show that 1 m below the surface, the 1993 deposits remain 5°C to 15°C hotter, 18 years after emplacement, than adjacent deposits. Based on the observed subsidence as well as estimated cooling rates, the fractures are inferred to be the combined result of deaeration, thermal contraction, and sedimentary compaction in the months to years following deposition. Significant environmental factors, including regional earthquakes in 1995 and 2007, accelerated settling at punctuated moments in time. The spatially variable fracture pattern relates to surface slope and lithofacies variations as well as substrate lithology. Similar fractures have been reported in other ignimbrites but are generally exposed only in cross section and are often attributed to formation by external forces. Here we suggest that such interpretations should be invoked with caution, and deformation including post-emplacement subsidence and fracturing of loosely packed ash-rich deposits in the months to years post-emplacement is a process inherent in the settling of pyroclastic material.

Subsurface transport program: Research summary

International Nuclear Information System (INIS)

1987-01-01

DOE's research program in subsurface transport is designed to provide a base of fundamental scientific information so that the geochemical, hydrological, and biological mechanisms that contribute to the transport and long term fate of energy related contaminants in subsurface ecosystems can be understood. Understanding the physical and chemical mechanisms that control the transport of single and co-contaminants is the underlying concern of the program. Particular attention is given to interdisciplinary research and to geosphere-biosphere interactions. The scientific results of the program will contribute to resolving Departmental questions related to the disposal of energy-producing and defense wastes. The background papers prepared in support of this document contain additional information on the relevance of the research in the long term to energy-producing technologies. Detailed scientific plans and other research documents are available for high priority research areas, for example, in subsurface transport of organic chemicals and mixtures and in the microbiology of deep aquifers. 5 figs., 1 tab

Plate boundary deformation and man-made subsidence around geothermal fields on the Reykjanes Peninsula, Iceland

KAUST Repository

Keiding, Marie; Á rnadó ttir, Thó ra; Jonsson, Sigurjon; Decriem, Judicaë l; Hooper, Andrew John

2010-01-01

We present Interferometric Synthetic Aperture Radar (InSAR) data from 1992-1999 and 2003-2008 as well as GPS data from 2000-2009 for the active plate boundary on the Reykjanes Peninsula, southwest Iceland. The geodetic data reveal deformation mainly due to plate spreading, anthropogenic subsidence caused by geothermal fluid extraction and, possibly, increasing pressure in a geothermal system. Subsidence of around 10. cm is observed during the first 2. years of production at the Reykjanes geothermal power plant, which started operating in May 2006. We model the surface subsidence around the new power plant using point and ellipsoidal pressure sources in an elastic halfspace. Short-lived swarms of micro-earthquakes as well as aseismic fault movement are observed near the geothermal field following the start of production, possibly triggered by the stresses induced by geothermal fluid extraction. © 2010 Elsevier B.V.

Plate boundary deformation and man-made subsidence around geothermal fields on the Reykjanes Peninsula, Iceland

KAUST Repository

Keiding, Marie

2010-07-01

We present Interferometric Synthetic Aperture Radar (InSAR) data from 1992-1999 and 2003-2008 as well as GPS data from 2000-2009 for the active plate boundary on the Reykjanes Peninsula, southwest Iceland. The geodetic data reveal deformation mainly due to plate spreading, anthropogenic subsidence caused by geothermal fluid extraction and, possibly, increasing pressure in a geothermal system. Subsidence of around 10. cm is observed during the first 2. years of production at the Reykjanes geothermal power plant, which started operating in May 2006. We model the surface subsidence around the new power plant using point and ellipsoidal pressure sources in an elastic halfspace. Short-lived swarms of micro-earthquakes as well as aseismic fault movement are observed near the geothermal field following the start of production, possibly triggered by the stresses induced by geothermal fluid extraction. © 2010 Elsevier B.V.

ANSTO - program of research 1991-1992

International Nuclear Information System (INIS)

1991-01-01

The direction and priorities of the Australian Nuclear Science and Technology Organisation (ANSTO) research program are outlined. During the period under review. Many of the initiatives of previous years come to fruition, adding significant strength and dimension to the Organisation's research capabilities. The advent of Australian Supercomputing Technology, a joint venture between Fujitsu Australia and ANSTO, will enable the grand challenges of computational science to underpin Ansto research generally but specifically in environmental science. The development of the accelerator mass spectrometry facilities on the tandem accelerator supported new initiatives in environmental research and management. The National Medical Cyclotron opens a new era in radiopharmaceutical research and development. Finally, the recently commissioned hot isostatic press provides a unique national resource for the development of new ceramics and their applications. The direction and priorities of Ansto's research program are determined through a combination of external and internal review. The Program Advisory Committees provide external evaluation against national objectives. New Committees have been formed and membership reflects the national and international nature of the ANSTO research programs. ills

Jointly Sponsored Research Program Energy Related Research

Energy Technology Data Exchange (ETDEWEB)

Western Research Institute

2009-03-31

Cooperative Agreement, DE-FC26-98FT40323, Jointly Sponsored Research (JSR) Program at Western Research Institute (WRI) began in 1998. Over the course of the Program, a total of seventy-seven tasks were proposed utilizing a total of $23,202,579 in USDOE funds. Against this funding, cosponsors committed $26,557,649 in private funds to produce a program valued at $49,760,228. The goal of the Jointly Sponsored Research Program was to develop or assist in the development of innovative technology solutions that will: (1) Increase the production of United States energy resources - coal, natural gas, oil, and renewable energy resources; (2) Enhance the competitiveness of United States energy technologies in international markets and assist in technology transfer; (3) Reduce the nation's dependence on foreign energy supplies and strengthen both the United States and regional economies; and (4) Minimize environmental impacts of energy production and utilization. Under the JSR Program, energy-related tasks emphasized enhanced oil recovery, heavy oil upgrading and characterization, coal beneficiation and upgrading, coal combustion systems development including oxy-combustion, emissions monitoring and abatement, coal gasification technologies including gas clean-up and conditioning, hydrogen and liquid fuels production, coal-bed methane recovery, and the development of technologies for the utilization of renewable energy resources. Environmental-related activities emphasized cleaning contaminated soils and waters, processing of oily wastes, mitigating acid mine drainage, and demonstrating uses for solid waste from clean coal technologies, and other advanced coal-based systems. Technology enhancement activities included resource characterization studies, development of improved methods, monitors and sensors. In general the goals of the tasks proposed were to enhance competitiveness of U.S. technology, increase production of domestic resources, and reduce environmental

The Future of Nearshore Processes Research: U.S. Integrated Coastal Research Program

Science.gov (United States)

Elko, N.; Feddersen, F.; Foster, D. L.; Hapke, C. J.; Holman, R. A.; McNinch, J.; Mulligan, R. P.; Ozkan-Haller, H. T.; Plant, N. G.; Raubenheimer, B.

2016-02-01

The authors, representing the acting Nearshore Advisory Council, have developed an implementation plan for a U.S. Nearshore Research Program based on the 2015 Future of Nearshore Processes report that was authored by the nearshore community. The objectives of the plan are to link research programs across federal agencies, NGOs, industry, and academia into an integrated national program and to increase academic and NGO participation in federal agency nearshore processes research. A primary recommendation is interagency collaboration to build a research program that will coordinate and fund U.S. nearshore processes research across three broad research themes: 1) long-term coastal evolution due to natural and anthropogenic processes; 2) extreme events; and 3) physical, biological and chemical processes impacting human and ecosystem health. The plan calls for a new program to be developed by an executive committee of federal agency leaders, NGOs, and an academic representative, created similarly to the existing NOPP program. This leadership will be established prior to the 2016 Ocean Sciences meeting and will have agreed on responsibilities and a schedule for development of the research program. To begin to understand the scope of today's U.S. coastal research investment, a survey was distributed to ten federal agency R&D program heads. Six of the ten agencies indicated that they fund coastal research, with a combined annual coastal research budget of nearly 100 million (NSF has not responded). The priority of the three research themes were ranked nearly equally and potential research support ranged from 15-19 million for each theme, with approximately 12 million as direct contribution to academic research. Beyond addressing our fundamental science questions, it is critical that the nearshore community stay organized to represent academic interests on the new executive committee. The program goal is the integration of academic, NGO, and federal agencies.

Programs of the Office of Energy Research

International Nuclear Information System (INIS)

1985-07-01

The purpose of this research has been to support the energy technology development programs by providing insight into fundamental science and associated phenomena and developing new or advanced concepts and techniques. Today, this responsibility rests with the Office of Energy Research (ER), DOE, whose present programs have their origins in pioneering energy-related research which was initiated nearly 40 years ago. The Director, Office of Energy Research, also acts as the chief scientist and scientific advisor to the Secretary of Energy for the entire spectrum of energy research and development (R and D) programs of the Department. ER programs include several thousand individual projects and hundreds of laboratories, universities, and other research facilities throughout the United States. The current organization of ER is shown. The budgets for the various ER programs for the last two fiscal years are shown. In the following pages, each of these programs and activities are described briefly for the information of the scientific community and the public at large

Ground subsidence monitoring of the Vega Media of the Segura River by means of Advanced differential Sar Interferometry

International Nuclear Information System (INIS)

Tomas, R.; Herrera, G.; Lopez-Sanchez, J. M.; Mallorqui, J. J.; Mulas, J.

2010-01-01

Ground subsidence caused by aquifer withdrawal is a geotechnical hazard that affects wide areas, causing high economic losses. This phenomenon id due to aquifer system fine soil consolidation produced by the increase of effective stress caused by piezo metric depletion. The Vega Media of the Segura River basin (SE Spain) has suffered this type of phenomena since 90s being until the moment the first documented case at a regional scale in Spain. In this work a Differential SAR Interferometry (DInSAR) remote sensing technique called Coherent Pixel (CPT) is applied to monitoring subsidence in the Vega Media of the Segura River using 81 SAR images provided by ERS-1, ERS-2 and ENVISAT European Space Agency satellites. The processing has provided the subsidence spatial distribution and temporal evolution for the whole study area showing maximum subsidence values near 15 cm for the 1994-2007 period. (Author) 33 refs.

Marine biosurfaces research program

Science.gov (United States)

The Office of Naval Research (ONR) of the U.S. Navy is starting a basic research program to address the initial events that control colonization of surfaces by organisms in marine environments. The program “arises from the Navy's need to understand and ultimately control biofouling and biocorrosion in marine environments,” according to a Navy announcement.The program, “Biological Processes Controlling Surface Modification in the Marine Environment,” will emphasize the application of in situ techniques and modern molecular biological, biochemical, and biophysical approaches; it will also encourage the development of interdisciplinary projects. Specific areas of interest include sensing and response to environmental surface (physiology/physical chemistry), factors controlling movement to and retention at surfaces (behavior/hydrodynamics), genetic regulation of attachment (molecular genetics), and mechanisms of attachment (biochemistry/surface chemistry).

High-resolution InSAR constraints on flood-related subsidence and evaporite dissolution along the Dead Sea shores: Interplay between hydrology and rheology

Science.gov (United States)

Shviro, Maayan; Haviv, Itai; Baer, Gidon

2017-09-01

Sinkhole generation and land subsidence are commonly attributed to dissolution of subsurface layers by under-saturated groundwater and formation of cavities. Along the Dead Sea (DS) shorelines, this process also involves seasonal flash floods that are drained into the subsurface by existing and newly formed sinkholes. We quantify the contribution of flash-floods to salt dissolution and land subsidence using high-resolution interferometric synthetic aperture radar (InSAR). Subsidence rates during a 3-year period (2012-2015) were calculated from 57 COSMO SkyMed X-band interferograms bracketing major flood events and intra-flood periods in 21 sinkhole sites. The sites are located within channels and alluvial fans along the western shores of the Dead Sea, Israel. The observed subsidence reaches maximum rates of 2.5 mm/day, accumulating in specific sites to 500 mm/year. In most of the sinkhole sites a gradual increase in the annual subsidence rate is observed during the 3-year study period. Three different modes of response to floods were observed: (1) sites where floodwater is not directly channeled into sinkholes do not respond to floods; (2) sites adjacent to active channels with sinkholes are unaffected by specific floods but their subsidence rates increase gradually from early winter to mid-summer, and decay gradually until the following winter; and (3) sites in active channels with sinkholes are characterized by an abrupt increase in subsidence rates immediately after each flood (by a factor of up to 20) and by a subsequent quasi-exponential subsidence decay over periods of several months. In these latter sites, subsidence rates after each flood are temporally correlated with alternating groundwater levels in adjacent boreholes. The rapid rise in groundwater head following floods increases the hydraulic gradient of the under-saturated groundwater and hence also the groundwater discharge and the dissolution rate of the subsurface salt layer. A subsequent quasi

Otolaryngology Residency Program Research Resources and Scholarly Productivity.

Science.gov (United States)

Villwock, Jennifer A; Hamill, Chelsea S; Nicholas, Brian D; Ryan, Jesse T

2017-06-01

Objective To delineate research resources available to otolaryngology residents and their impact on scholarly productivity. Study Design Survey of current otolaryngology program directors. Setting Otolaryngology residency programs. Subjects and Methods An anonymous web-based survey was sent to 98 allopathic otolaryngology training program directors. Fisher exact tests and nonparametric correlations were used to determine statistically significant differences among various strata of programs. Results Thirty-nine percent (n = 38) of queried programs responded. Fourteen (37%) programs had 11 to 15 full-time, academic faculty associated with the residency program. Twenty (53%) programs have a dedicated research coordinator. Basic science lab space and financial resources for statistical work were present at 22 programs (58%). Funding is uniformly provided for presentation of research at conferences; a minority of programs (13%) only funded podium presentations. Twenty-four (63%) have resident research requirements beyond the Accreditation Council for Graduate Medical Education (ACGME) mandate of preparing a "manuscript suitable for publication" prior to graduation. Twenty-five (67%) programs have residents with 2 to 3 active research projects at any given time. None of the investigated resources were significantly associated with increased scholarly output. There was no uniformity to research curricula. Conclusions Otolaryngology residency programs value research, evidenced by financial support provided and requirements beyond the ACGME minimum. Additional resources were not statistically related to an increase in resident research productivity, although they may contribute positively to the overall research experience during training. Potential future areas to examine include research curricula best practices, how to develop meaningful mentorship and resource allocation that inspires continued research interest, and intellectual stimulation.

Mechanisms of subsidence for induced damage and techniques for analysis

International Nuclear Information System (INIS)

Drumm, E.C.; Bennett, R.M.; Kane, W.F.

1988-01-01

Structural damage due to mining induced subsidence is a function of the nature of the structure and its position on the subsidence profile. A point on the profile may be in the tensile zone, the compressive zone, or the no-deformation zone at the bottom of the profile. Damage to structures in the tension zone is primarily due to a reduction of support during vertical displacement of the ground surface, and to shear stresses between the soil and structure resulting from horizontal displacements. The damage mechanisms due to tension can be investigated effectively using a two-dimensional plane stress analysis. Structures in the compression zone are subjected to positive moments in the footing and large compressive horizontal stresses in the foundation walls. A plane strain analysis of the foundation wall is utilized to examine compression zone damage mechanisms. The structural aspects affecting each mechanism are identified and potential mitigation techniques are summarized

Regional and local land subsidence at the Venice coastland by TerraSAR-X PSI

Directory of Open Access Journals (Sweden)

L. Tosi

2015-11-01

Full Text Available Land subsidence occurred at the Venice coastland over the 2008–2011 period has been investigated by Persistent Scatterer Interferometry (PSI using a stack of 90 TerraSAR-X stripmap images with a 3 m resolution and a 11-day revisiting time. The regular X-band SAR acquisitions over more than three years coupled with the very-high image resolution has significantly improved the monitoring of ground displacements at regional and local scales, e.g., the entire lagoon, especially the historical palaces, the MoSE large structures under construction at the lagoon inlets to disconnect the lagoon from the Adriatic Sea during high tides, and single small structures scattered within the lagoon environments. Our results show that subsidence is characterized by a certain variability at the regional scale with superimposed important local displacements. The movements range from a gentle uplift to subsidence rates of up to 35 mm yr−1. For instance, settlements of 30–35 mm yr−1 have been detected at the three lagoon inlets in correspondence of the MoSE works, and local sinking bowls up to 10 mm yr−1 connected with the construction of new large buildings or restoration works have been measured in the Venice and Chioggia historical centers. Focusing on the city of Venice, the mean subsidence of 1.1 ± 1.0 mm yr−1 confirms the general stability of the historical center.

National Geospatial-Intelligence Agency Academic Research Program

Science.gov (United States)

Loomer, S. A.

2004-12-01

"Know the Earth.Show the Way." In fulfillment of its vision, the National Geospatial-Intelligence Agency (NGA) provides geospatial intelligence in all its forms and from whatever source-imagery, imagery intelligence, and geospatial data and information-to ensure the knowledge foundation for planning, decision, and action. To achieve this, NGA conducts a multi-disciplinary program of basic research in geospatial intelligence topics through grants and fellowships to the leading investigators, research universities, and colleges of the nation. This research provides the fundamental science support to NGA's applied and advanced research programs. The major components of the NGA Academic Research Program (NARP) are: - NGA University Research Initiatives (NURI): Three-year basic research grants awarded competitively to the best investigators across the US academic community. Topics are selected to provide the scientific basis for advanced and applied research in NGA core disciplines. - Historically Black College and University - Minority Institution Research Initiatives (HBCU-MI): Two-year basic research grants awarded competitively to the best investigators at Historically Black Colleges and Universities, and Minority Institutions across the US academic community. - Director of Central Intelligence Post-Doctoral Research Fellowships: Fellowships providing access to advanced research in science and technology applicable to the intelligence community's mission. The program provides a pool of researchers to support future intelligence community needs and develops long-term relationships with researchers as they move into career positions. This paper provides information about the NGA Academic Research Program, the projects it supports and how other researchers and institutions can apply for grants under the program.

Advanced maintenance research programs

International Nuclear Information System (INIS)

Marston, T.U.; Gelhaus, F.; Burke, R.

1985-01-01

The purpose of this paper is to provide the reader with an idea of the advanced maintenance research program at the Electric Power Research Institute (EPRI). A brief description of the maintenance-related activities is provided as a foundation for the advanced maintenance research projects. The projects can be divided into maintenance planning, preventive maintenance program development and implementation, predictive (or conditional) maintenance, and innovative maintenance techniques. The projects include hardware and software development, human factors considerations, and technology promotion and implementation. The advanced concepts include: the incorporation of artificial intelligence into outage planning; turbine and pump maintenance; rotating equipment monitoring and diagnostics with the aid of expert systems; and the development of mobile robots for nuclear power plant maintenance

Lewis' Educational and Research Collaborative Internship Program

Science.gov (United States)

Heyward, Ann; Gott, Susan (Technical Monitor)

2004-01-01

The Lewis Educational and Research Collaborative Internship Program (LERCIP) is a collaborative undertaking by the Office of Educational Programs at NASA Glenn Research Center at Lewis Field (formerly NASA Lewis Research Center) and the Ohio Aerospace Institute. This program provides 10-week internships in addition to summer and winter extensions if funding is available and/or is requested by mentor (no less than 1 week no more than 4 weeks) for undergraduate/graduate students and secondary school teachers. Students who meet the travel reimbursement criteria receive up to $500 for travel expenses. Approximately 178 interns are selected to participate in this program each year and begin arriving the fourth week in May. The internships provide students with introductory professional experiences to complement their academic programs. The interns are given assignments on research and development projects under the personal guidance of NASA professional staff members. Each intern is assigned a NASA mentor who facilitates a research assignment. In addition to the research assignment, the summer program includes a strong educational component that enhances the professional stature of the participants. The educational activities include a research symposium and a variety of workshops, and lectures. An important aspect of the program is that it includes students with diverse social, cultural and economic backgrounds. The purpose of this report is to document the program accomplishments for 2004.

Employment effects of active labor market programs for sick-listed workers

DEFF Research Database (Denmark)

Holm, Anders; Høgelund, Jan; Gørtz, Mette

2017-01-01

We use register data of 88,948 sick-listed workers in Denmark over the period 2008–2011 to investigate the effect of active labor market programs on the duration until returning to non-subsidized employment and the duration of this employment. To identify causal treatment effects, we exploit over......-time variation in the use of active labor market programs in 98 job centers and time-to- event. We find that ordinary education and subsidized job training have significant positive employment effects. Subsidized job training has a large, positive effect on the transition into employment but no effect...... on the subsequent employment duration. In contrast, ordinary education has a positive effect on employment duration but no effect on the transition into employment. The latter effect is the result of two opposing effects, a large positive effect of having completed education and a large negative lock-in effect...

Human Research Program Science Management: Overview of Research and Development Activities

Science.gov (United States)

Charles, John B.

2007-01-01

An overview of research and development activities of NASA's Human Research Science Management Program is presented. The topics include: 1) Human Research Program Goals; 2) Elements and Projects within HRP; 3) Development and Maintenance of Priorities; 4) Acquisition and Evaluation of Research and Technology Proposals; and 5) Annual Reviews

Small business innovation research program solicitation

Science.gov (United States)

1994-01-01

The National Aeronautics and Space Administration invites eligible small business concerns to submit Phase 1 proposals for its 1994 Small Business Innovation Research (SBIR) Program, which is described in this twelfth annual NASA SBIR Program Solicitation. The 1994 solicitation period for Phase 1 proposals begins April 4, 1994 and ends June 15, 1994. Eligible firms with research or research and development capabilities (R/R&D) in any of the listed topic and subtopic areas are encouraged to participate. Through SBIR, NASA seeks innovative concepts addressing the program needs described in the SBIR solicitation subtopics and offering commercial application potential. This document contains program background information, outlines eligibility requirements for SBIR participants, describes the three SBIR program phases, and provides the information qualified offerors need to prepare and submit responsive proposals.

Consideration of the restoring plan in subsidence prone areas through the development of ground stability assessment techniques

Energy Technology Data Exchange (ETDEWEB)

Kwon, Kwang-Soo; Kim, Im-Ho; Baek, Sang-Ho [Korea Institute of Geology Mining and Materials, Taejon (KR)] (and others)

1999-12-01

This report consists of 2 subjects. (1) Consideration of the restoring plan in subsidence prone areas through the development of ground stability assessment techniques : The number of mines at rest as well as closed have abruptly increased since the 1980's, which has caused subsidence problems around the mined areas. To protect such places from damage due to subsidence, it is necessary to develop the assessment techniques of ground stability and make restoration plan. To achieve this goal, the site investigation should have been conducted before the subsidence events occurred, but ground behaviors around the places where a vertical movement is expected and recognised in advance before the occurrence of the subsidence events. In this study ground stability analysis for the area surrounding the Moo-Geuk Mine, located close to a city, was conducted and the measurements were recorded. The objectives of the present study include, the development of a risk assessment technique for the subsidence using GIS tool, an evaluation of the numerical methods related to the site investigation and the ground stability analysis, the application of the numerical tools to the present problems. (2) Integration of coal mine data and use of remote sensing in investigation of coal mine area : This study attempt to integrate the previous geological and mining data to avoid confusions often occurred when accessing source data. And the investigation of underground mining place using remote sensing method is the other effort to assure the geographic locations of mining places as well as to find out unknown mining place. The sample region for examining the remote sensing method is the Chungnam coal field, which locates in the middle western part of South Korea. Detailed investigation was held on the Seongju area, locating north eastern part of the coal field. (author). 54 refs., tabs., figs.

SAR interferometry monitoring of subsidence in a detritic basin related to water depletion in the underlying confined carbonate aquifer (Torremolinos, southern Spain).

Science.gov (United States)

Ruiz-Constán, A; Ruiz-Armenteros, A M; Martos-Rosillo, S; Galindo-Zaldívar, J; Lazecky, M; García, M; Sousa, J J; Sanz de Galdeano, C; Delgado-Blasco, J M; Jiménez-Gavilán, P; Caro-Cuenca, M; Luque-Espinar, J A

2018-04-30

This research underlines the need to improve water management policies for areas linked to confined karstic aquifers subjected to intensive exploitation, and to develop additional efforts towards monitoring their subsidence evolution. We analyze subsidence related to intensive use of groundwater in a confined karstic aquifer, through the use of the InSAR technique, by the southern coast of Spain (Costa del Sol). Carbonates are overlain by an unconfined detritic aquifer with interlayered high transmissivity rocks, in connection with the Mediterranean Sea, where the water level is rather stable. Despite this, an accumulated deformation in the line-of-sight (LOS) direction greater than -100 mm was observed by means of the ERS-1/2 (1992-2000) and Envisat (2003-2009) satellite SAR sensors. During this period, the Costa del Sol experienced a major population increase due to the expansion of the tourism industry, with the consequent increase in groundwater exploitation. The maximum LOS displacement rates recorded during both time spans are respectively -6 mm/yr and -11 mm/yr, respectively. During the entire period, there was an accumulated descent of the confined water level of 140 m, and several fluctuations of more than 80 m correlating with the subsidence trend observed for the whole area. Main sedimentary depocenters (up to 800 m), revealed by gravity prospecting, partly coincide with areas of subsidence maxima; yet ground deformation is also influenced by other factors, the main ones being the fine-grained facies distribution and rapid urbanization due to high touristic pressure. Copyright © 2018 Elsevier B.V. All rights reserved.

ANSTO - Program of Research 1993-1994

International Nuclear Information System (INIS)

1993-01-01

The 1993-1994 Program of Research outlines ANSTO's scientific activities in four key research areas, Advanced Materials, Application of Nuclear Physics, Biomedicine and Health and Environmental Science. The effort has been channeled into applied research and development in partnership with industry and appropriate national and international institutions and into interdisciplinary strategic research projects to enhance the scientific base of the key research activities. A list of scientific publications originated from these program areas is also included. ills

National Research Council Research Associateships Program with Methane Hydrates Fellowships Program/National Energy Technology Laboratory

Energy Technology Data Exchange (ETDEWEB)

Basques, Eric O. [National Academy of Sciences, Washington, DC (United States)

2014-03-20

This report summarizes work carried out over the period from July 5, 2005-January 31, 2014. The work was carried out by the National Research Council Research Associateships Program of the National Academies, under the US Department of Energy's National Energy Technology Laboratory (NETL) program. This Technical Report consists of a description of activity from 2005 through 2014, broken out within yearly timeframes, for NRC/NETL Associateships researchers at NETL laboratories which includes individual tenure reports from Associates over this time period. The report also includes individual tenure reports from associates over this time period. The report also includes descriptions of program promotion efforts, a breakdown of the review competitions, awards offered, and Associate's activities during their tenure.

Review of defense display research programs

Science.gov (United States)

Tulis, Robert W.; Hopper, Darrel G.; Morton, David C.; Shashidhar, Ranganathan

2001-09-01

Display research has comprised a substantial portion of the defense investment in new technology for national security for the past 13 years. These investments have been made by the separate service departments and, especially, via several Defense Research Projects Agency (DARPA) programs, known collectively as the High Definition Systems (HDS) Program (which ended in 2001) and via the Office of the Secretary of Defense (OSD) Defense Production Act (DPA) Title III Program (efforts ended in 2000). Using input from the Army, Navy, and Air Force to focus research and identify insertion opportunities, DARPA and the Title III Program Office have made investments to develop the national technology base and manufacturing infrastructure necessary to meet the twin challenge of providing affordable displays in current systems and enabling the DoD strategy of winning future conflicts by getting more information to all participants during the battle. These completed DARPA and DPA research and infrastructure programs are reviewed. Service investments have been and are being made to transition display technology; examples are described. Display science and technology (S&T) visions are documented for each service to assist the identification of areas meriting consideration for future defense research.

The Australian synchrotron research program

International Nuclear Information System (INIS)

Garrett, R.F.

1998-01-01

Full text: The Australian Synchrotron Research Program (ASRP) was established in 1996 under a 5 year grant from the Australian Government, and is managed by ANSTO on behalf of a consortium of Australian universities and research organisations. It has taken over the operation of the Australian National Beamline Facility (ANBF) at the Photon Factory, and has joined two CATS at the Advanced Photon Source: the Synchrotron Radiation Instrumentation CAT (SRI-CAT) and the Consortium for Advanced Radiation Sources (CARS). The ASRP thus manages a comprehensive range of synchrotron radiation research facilities for Australian science. The ANBF is a general purpose hard X-ray beamline which has been in operation at the Photon Factory since 1993. It currently caters for about 35 Australian research teams per year. The facilities available at the ANBF will be presented and the research program will be summarised. The ASRP facilities at the APS comprise the 5 sectors operated by SRI-CAT, BioCARS and ChemMatCARS. A brief description will be given of the ASRP research programs at the APS, which will considerably broaden the scope of Australian synchrotron science

Environmental research program. 1992 annual report

Energy Technology Data Exchange (ETDEWEB)

1993-07-01

The objective of the Environmental Research Program is to contribute to the understanding of the formation, mitigation, transport, transformation, and ecological effects of energy-related pollutants on the environment. The program is multidisciplinary and includes fundamental and applied research in chemistry, physics, biology, engineering, and ecology. The program undertakes research and development in efficient and environmentally benign combustion, pollution abatement and destruction, and novel methods of detection and analysis of criteria and non-criteria pollutants. This diverse group investigates combustion, atmospheric processes, flue-gas chemistry, and ecological systems.

Natural versus anthropogenic subsidence of Venice: investigation of the present occurrence by PSI

Science.gov (United States)

Tosi, Luigi; Strozzi, Tazio; Teatini, Pietro

2014-05-01

We detected land displacements of Venice by Persistent Scatterer Interferometry (PSI) using ERS and ENVISAT C-band and TerraSAR-X and COSMO-SkyMed X-band acquisitions over the periods 1992-2010 and 2008-2011, respectively. PSI provides the cumulative land displacements (natural plus anthropogenic) of the investigated area independently of the radar band. The natural subsidence rate depends on the reference period and, due to the present elevation of Venice with respect to the sea level, it is much more interesting for the city to evaluate the natural displacement over the last few decades, i.e. the present natural land subsidence, than that averaged over geological periods. Concerning anthropogenic land subsidence the contribution due to activities characterized by large scale and long term effects, e.g., that caused by groundwater withdrawals, ended a few decades ago. Today, the anthropogenic component of the land subsidence is only due to local, short-time interventions such as restoration works and inherent deformations of historical structures. By reason of the larger observation period, the C-band sensors were used to quantify the long-term movements, i.e. the subsidence component primarily ascribed to natural processes. The high resolution, short revisiting time X-band satellites reveal a high effectiveness to monitor short-time movements as those induced by human activities. The statistical analysis of the displacement distributions measured by PSI points out that the average rates, i.e. the natural component of the subsidence, are almost equal with the C-band and X-band satellites. Conversely, the standard deviation with X-band acquisitions (1.6 mm/yr) is characterized by a value significantly larger than that detected with C-band images (0.7 mm/yr). The larger X-band variability superposes to a background velocity similar to that given by ERS/ENVISAT. It is reasonable to assume that the difference between the movements provided by ERS/ENVISAT and Terra

Quaternary development of resilient reefs on the subsiding kimberley continental margin, Northwest Australia

Directory of Open Access Journals (Sweden)

Lindsay B. Collins

2010-01-01

Full Text Available The Kimberley region in remote northwest Australia has poorly known reef systems of two types; coastal fringing reefs and atoll-like shelf-edge reefs. As a major geomorphic feature (from 12ºS to 18ºS situated along a subsiding continental margin, the shelf edge reefs are in a tropical realm with warm temperatures, relatively low salinity, clear low nutrient waters lacking sediment input, and Indo-West Pacific corals of moderate diversity. Seismic architecture of the Rowley Shoals reveals that differential pre-Holocene subsidence and relative elevation of the pre-Holocene substrate have controlled lagoon sediment infill and reef morphology, forming an evolutionary series reflecting differential accommodation in three otherwise similar reef systems. The Holocene core described for North Scott Reef confirms previous seismic interpretations, and provides a rare ocean-facing reef record. It demonstrates that the Indo-Pacific reef growth phase (RG111 developed during moderate rates of sea level rise of 10 mm/year from 11 to about 7-6.5 ka BP until sea level stabilization, filling the available 27 m of pre-Holocene accommodation. Despite the medium to high hydrodynamic energy imposed by the 4m tides, swell waves and cyclones the reef-building communities represent relatively low-wave energy settings due to their southeast facing and protection afforded by the proximity of the South Reef platform. This study demonstrates the resilience of reefs on the subsiding margin whilst linking Holocene reef morphology to the relative amount of pre-Holocene subsidence.Kimberly é uma região remota e pouco conhecida, localizada no noroeste da Austrália, ali são encontrados dois sistemas recifais: recifes costeiros de franja e os tipo-atois localizados na margem da plataforma continental. Esses recifes formam a feição geomórfica mais importante entre 12ºS a 18ºS estando localizados ao longo de uma margem continental em subsidência. Esses recifes encontram

Subsidized Housing, Public Housing, and Adolescent Violence and Substance Use

Science.gov (United States)

Leech, Tamara G. J.

2012-01-01

This study examines the separate relationships of public housing residence and subsidized housing residence to adolescent health risk behavior. Data include 2,530 adolescents aged 14 to 19 who were children of the National the Longitudinal Study of Youth. The author used stratified propensity methods to compare the behaviors of each…

Improving Defense Health Program Medical Research Processes

Science.gov (United States)

2017-08-08

research , including a Business Cell; 87 Research Development, 88 Research Oversight, 89 and Research Compliance offices;90 and the Center...needed for DHP medical research , such as the Army’s Clinical and Translational Research Program Office, 38 the Navy’s Research Methods Training Program... research stated, “key infrastructure for a learning health system will encompass three core elements: data networks, methods , and workforce.” 221

USNRC HTGR safety research program overview

International Nuclear Information System (INIS)

Foulds, R.B.

1982-01-01

An overview is given of current activities and planned research efforts of the US Nuclear Regulatory Commission (NRC) HTGR Safety Program. On-going research at Brookhaven National Laboratory, Oak Ridge National Laboratory, Los Alamos National Laboratory, and Pacific Northwest Laboratory are outlined. Tables include: HTGR Safety Issues, Program Tasks, HTGR Computer Code Library, and Milestones for Long Range Research Plan

Collaborative Aerospace Research and Fellowship Program at NASA Glenn Research Center

Science.gov (United States)

Heyward, Ann O.; Kankam, Mark D.

2004-01-01

During the summer of 2004, a 10-week activity for university faculty entitled the NASA-OAI Collaborative Aerospace Research and Fellowship Program (CFP) was conducted at the NASA Glenn Research Center in collaboration with the Ohio Aerospace Institute (OAI). This is a companion program to the highly successful NASA Faculty Fellowship Program and its predecessor, the NASA-ASEE Summer Faculty Fellowship Program that operated for 38 years at Glenn. The objectives of CFP parallel those of its companion, viz., (1) to further the professional knowledge of qualified engineering and science faculty,(2) to stimulate an exchange of ideas between teaching participants and employees of NASA, (3) to enrich and refresh the research and teaching activities of participants institutions, and (4) to contribute to the research objectives of Glenn. However, CFP, unlike the NASA program, permits faculty to be in residence for more than two summers and does not limit participation to United States citizens. Selected fellows spend 10 weeks at Glenn working on research problems in collaboration with NASA colleagues and participating in related activities of the NASA-ASEE program. This year's program began officially on June 1, 2004 and continued through August 7, 2004. Several fellows had program dates that differed from the official dates because university schedules vary and because some of the summer research projects warranted a time extension beyond the 10 weeks for satisfactory completion of the work. The stipend paid to the fellows was $1200 per week and a relocation allowance of $1000 was paid to those living outside a 50-mile radius of the Center. In post-program surveys from this and previous years, the faculty cited numerous instances where participation in the program has led to new courses, new research projects, new laboratory experiments, and grants from NASA to continue the work initiated during the summer. Many of the fellows mentioned amplifying material, both in

Regulatory research program for 1987/88

International Nuclear Information System (INIS)

1987-01-01

The regulatory research program of Canada's Atomic Energy Control Board (AECB) is intended to augment the AECB's research program beyond the capability of in-house resources. The overall objective of the research program is to produce pertinent and independent information that will assist the Board and its staff in making correct, timely and credible decisions on regulating nuclear energy. The program covers the following areas: the safety of nuclear facilities, radioactive waste management, health physics, physical security, and the development of regulatory processes. Sixty-seven projects are planned for 1987/88; as well, there are some projects held in reserve in case funding becomes available. This information bulletin contains a list of the projects with a brief description of each

Southern Perú coseismic subsidence: 23 June 2001 8.4-Mw earthquake

Directory of Open Access Journals (Sweden)

L. Ocola

2008-01-01

Full Text Available The 23-June-2001 8.4-Mw magnitude earthquake partially filled the 1868-seismic-gap in southern Perú. This earthquake produced a thrust faulting dislocation with a rupture that started at about ~200 km SE from the 1996's Nazca earthquake epicenter, and stopped near Ilo, at about 300 km from the epicenter, near a positive gravity anomaly offshore Ilo. The 23-June-2001-earthquake dislocation zone is under the Arequipa sedimentary Basin. Pre- and post-seismic GPS measurements at Camaná and Ilo at SIRGAS-GPS points (SIRGAS: Sistema de Referencia Geocéntrico para América del Sur and the average sea level pre- and post-seismic event at Mollendo tide gauge provide evidence of a regional subsidence of southern Perú, with 84 cm at Camaná, 16 cm at Ilo, and 15 cm at Mollendo. Field surveys post earthquake document significant subsidence in Camaná resort beaches. Results of a simple dislocation modelling of 23-June-2001 earthquake agree reasonably well with the observed data. However, the coseismic subsidence of southern Perú is at variance with the regional uplift of southern Perú based on Neotectonic studies. This fact, suggests that, in recent geological times, the magnitude of the secular uplift due to tectonic plate converge has been larger than the coseismic deformation recovery.

Surveys for detection and measurement of subsidence resulting from solution mining--why, what and how

International Nuclear Information System (INIS)

Piper, T.B.

1983-01-01

Subsidence resulting from solution mining is usually expressed at the earth's surface by downwarping or change in elevation. Areas of several tens or hundreds of acres are involved. These settlements can sometimes be accommodated by buildings and other installations if the subsidence is gentle or the area is large. On the other hand, mineral extraction sometimes results in collapse of a relatively small area (on the order of a few acres) known as a sinkhole. The relationship between these two events has not been demonstrated. Subsidence can be detected by measurements made in the area involved by either access or non-access methods. The results provide early warning of surface downwarping and can be used as input in operating decisions. Precise levelling of a network of shallow monuments has shown a high level of applicability to solution mining sites and offers the maximum cost-benefit ratio. Time vs. settlement plots and summary contour maps serve to present the data and identify areas of concern

Heterogeneous rupture in the great Cascadia earthquake of 1700 inferred from coastal subsidence estimates

Science.gov (United States)

Wang, Pei-Ling; Engelhart, Simon E.; Wang, Kelin; Hawkes, Andrea D.; Horton, Benjamin P.; Nelson, Alan R.; Witter, Robert C.

2013-01-01

Past earthquake rupture models used to explain paleoseismic estimates of coastal subsidence during the great A.D. 1700 Cascadia earthquake have assumed a uniform slip distribution along the megathrust. Here we infer heterogeneous slip for the Cascadia margin in A.D. 1700 that is analogous to slip distributions during instrumentally recorded great subduction earthquakes worldwide. The assumption of uniform distribution in previous rupture models was due partly to the large uncertainties of then available paleoseismic data used to constrain the models. In this work, we use more precise estimates of subsidence in 1700 from detailed tidal microfossil studies. We develop a 3-D elastic dislocation model that allows the slip to vary both along strike and in the dip direction. Despite uncertainties in the updip and downdip slip extensions, the more precise subsidence estimates are best explained by a model with along-strike slip heterogeneity, with multiple patches of high-moment release separated by areas of low-moment release. For example, in A.D. 1700, there was very little slip near Alsea Bay, Oregon (~44.4°N), an area that coincides with a segment boundary previously suggested on the basis of gravity anomalies. A probable subducting seamount in this area may be responsible for impeding rupture during great earthquakes. Our results highlight the need for more precise, high-quality estimates of subsidence or uplift during prehistoric earthquakes from the coasts of southern British Columbia, northern Washington (north of 47°N), southernmost Oregon, and northern California (south of 43°N), where slip distributions of prehistoric earthquakes are poorly constrained.

Detailed quantification of delta subsidence, compaction and interaction with man-made structures: the case of the NCA airport, France

Science.gov (United States)

Cavalié, O.; Sladen, A.; Kelner, M.

2015-09-01

River deltas are dynamic coastal systems and their evolutions are closely monitored as it often concentrates vital natural resources for the surrounding areas. Many deltas worldwide experience subsidence due to geological processes (sediment loading and compaction) or human activities (groundwater or hydrocarbon extraction, land reclamation). This causes shoreline erosion or wetland loss which represent serious issues for the population. In this study we investigate the dynamic of the Var delta (France) where reclaimed lands over sea have been built to host the Nice côte d'Azur airport (NCA). Actually, the stability of this infrastructure is a permanent concern since, in 1979, a newly built extension of the runway platform collapsed in the sea, causing important damages. The project of land extension stopped, but the present airport platform is still located on reclaimed land. Factors that can trigger such catastrophic landslide are thought to be linked to the delta activity and the artificial airport platform load. We used, therefore, Envisat InSAR data to measure accurately the ground deformation of the area that includes the Var delta and NCA airport. Combining data from ascending and descending orbits, we estimated the east-west and vertical components of the deformation and obtained very accurate displacement rate (with a 1σ error of 0.25 mm yr-1). We found that nearly all the deformation is vertical and impacts the whole Var delta. The Var valley subsides at a very low rate (0.5-1 mm yr-1) but downstream the subsidence rate increases and a clear jump is observed at the transition with the reclaimed lands (1-2 mm yr-1). On average, the reclaimed lands subside at 3 mm yr-1. Since the subsidence rate increases in correlation with the sediment thickness, we interpret it as the compaction of the delta quaternary sedimentary wedge. In addition, three areas subside faster (between 5 and 10 mm yr-1), with one calling for more attention as it is the largest and

Estimating the distribution of salt cavern squeeze using subsidence measurements

NARCIS (Netherlands)

Fokker, P.A.; Visser, J.

2014-01-01

We report a field study on solution mining of magnesium chloride from bischofite layers in the Netherlands at depths between 1500 and 1850 m. Subsidence that was observed in the area is due to part of the brine production being realized by cavern squeeze; some of which were connccted. Wc used an

Base Program on Energy Related Research

Energy Technology Data Exchange (ETDEWEB)

Western Research Institute

2008-06-30

The main objective of the Base Research Program was to conduct both fundamental and applied research that will assist industry in developing, deploying, and commercializing efficient, nonpolluting fossil energy technologies that can compete effectively in meeting the energy requirements of the Nation. In that regard, tasks proposed under the WRI research areas were aligned with DOE objectives of secure and reliable energy; clean power generation; development of hydrogen resources; energy efficiency and development of innovative fuels from low and no-cost sources. The goal of the Base Research Program was to develop innovative technology solutions that will: (1) Increase the production of United States energy resources--coal, natural gas, oil, and renewable energy resources; (2) Enhance the competitiveness of United States energy technologies in international markets and assist in technology transfer; (3) Reduce the nation's dependence on foreign energy supplies and strengthen both the United States and regional economies; and (4) Minimize environmental impacts of energy production and utilization. This report summarizes the accomplishments of the overall Base Program. This document represents a stand-alone Final Report for the entire Program. It should be noted that an interim report describing the Program achievements was prepared in 2003 covering the progress made under various tasks completed during the first five years of this Program.

[Subsidence and its effects on the anterior plate stabilization in the course of cervical interbody spondylodesis. Part II. Clinical evaluation. Study design].

Science.gov (United States)

Hakało, Jerzy; Wroński, Jerzy

2003-01-01

Subsidence is a common phenomenon in the process of interbody fusion. The paper presents a retrospective clinical and radiological evaluation of subsidence in a group of 23 patients after cervical corpectomy with mesh cage and plate stabilization. Subsidence magnitude and its impact on the stabilizing system and on the clinical and radiological outcome were estimated. The mesh cage and cervical plate stabilization was preformed after one- (20 cases) or two-level (3 cases) corpectomy. The patients' mean age was 35 years (age range 18-72); 9 patients were aged over 50. Indications to corpectomy were: neurological impairment due to burst body fractures in 14 cases, multilevel spondylosis in 5, and OPLL in 2 patients. One patient had a kidney cancer metastasis. The mean follow-up period was 17 months (range 12-28 mo.). The patients' clinical status was evaluated using the ASIA scale in the post-traumatic group, and the Odom criteria in spondylotic cases. In all the cases pain severity was estimated by the VAS scale. Magnitude of subsidence was measured on consecutive lateral x-rays during the follow-up. Bone fusion was confirmed after 3 months in lateral flexion-extension x-rays. Changes in the local and general cervical lordosis were evaluated during the follow-up. A 72-year-old patient died after 6 weeks due to causes unrelated to the surgery. In all the remaining patients bone fusion was attained. There were no cases of the clinical status deterioration during the follow-up. Subsidence of over 1 mm was found in 19 patients (86.4%). The mean value of subsidence was 2.2 mm, but in a group of older patients (aged over 50) it amounted to 2.8 mm. In 4 cases (18.1%) with hardware complications, i.e. a screw breakage or slipping, the mean subsidence magnitude was 4.3 mm. Local and general cervical lordosis were maintained during the follow-up period, even in the group with excessive subsidence. The screw breakage site was invariably the round hole of the plate. The

Fusion program research materials inventory

International Nuclear Information System (INIS)

Roche, T.K.; Wiffen, F.W.; Davis, J.W.; Lechtenberg, T.A.

1984-01-01

Oak Ridge National Laboratory maintains a central inventory of research materials to provide a common supply of materials for the Fusion Reactor Materials Program. This will minimize unintended material variations and provide for economy in procurement and for centralized record keeping. Initially this inventory is to focus on materials related to first-wall and structural applications and related research, but various special purpose materials may be added in the future. The use of materials from this inventory for research that is coordinated with or otherwise related technically to the Fusion Reactor Materials Program of DOE is encouraged

Program of Research in Aeronautics

Science.gov (United States)

1981-01-01

A prospectus of the educational and research opportunities available at the Joint Institute for Advancement of Flight Sciences, operated at NASA Langley Research Center in conjunction with George Washington University's School of Engineering and Applied Sciences is presented. Requirements of admission to various degree programs are given as well as the course offerings in the areas of acoustics, aeronautics, environmental modelling, materials science, and structures and dynamics. Research facilities for each field of study are described. Presentations and publications (including dissertations and theses) generated by each program are listed as well as faculty members visting scientists and engineers.

The undergraduate research fellows program: a unique model to promote engagement in research.

Science.gov (United States)

Vessey, Judith A; DeMarco, Rosanna F

2008-01-01

Well-educated nurses with research expertise are needed to advance evidence-based nursing practice. A primary goal of undergraduate nursing curricula is to create meaningful participatory experiences to help students develop a research skill set that articulates with rapid career advancement of gifted, young graduates interested in nursing research and faculty careers. Three research enrichment models-undergraduate honors programs, research assistant work-for-hire programs, and research work/mentorship programs-to be in conjunction with standard research content are reviewed. The development and implementation of one research work/mentorship program, the Boston College undergraduate research fellows program (UGRF), is explicated. This process included surveying previous UGRFs followed by creating a retreat and seminars to address specific research skill sets. The research skill sets included (a) how to develop a research team, (b) accurate data retrieval, (c) ethical considerations, (d) the research process, (e) data management, (f) successful writing of abstracts, and (g) creating effective poster presentations. Outcomes include evidence of involvement in research productivity and valuing of evidenced-based practice through the UGRF mentorship process with faculty partners.

Numerical modelling of surface subsidence arising from longwall mining of steeply inclined coal seams

Energy Technology Data Exchange (ETDEWEB)

Nejad, M.A.; Reddish, D.J. [University of Nottingham, Nottingham (United Kingdom). School of Chemical, Environmental and Mining Engineering

1998-12-31

The paper presents results from and the methodology of a numerical modelling investigation into the surface ground movements above longwall mining of inclined and steep seams with varying panel configurations. A modelling approach was developed using a finite difference numercial model Fast Lagrangian Analysis of Continua (FLAC). On the basis of this methodology, representative surface subsidence profiles were simulated and the results of simulations were validated against the UK data using the Subsidence Engineer`s Handbook (SEH) and influence function methods. Furthermore, the proposed methodology was applied to two UK case histories for validation purposes. 15 refs., 7 figs., 3 tabs.

Overview of the Defense Programs Research and Technology Development Program for fiscal year 1993. Appendix II research laboratories and facilities

Energy Technology Data Exchange (ETDEWEB)

1993-09-30

This document contains summaries of the research facilities that support the Defense Programs Research and Technology Development Program for FY 1993. The nine program elements are aggregated into three program clusters as follows: (1) Advanced materials sciences and technologies; chemistry and materials, explosives, special nuclear materials (SNM), and tritium. (2) Design sciences and advanced computation; physics, conceptual design and assessment, and computation and modeling. (3) Advanced manufacturing technologies and capabilities; system engineering science and technology, and electronics, photonics, sensors, and mechanical components. Section I gives a brief summary of 23 major defense program (DP) research and technology facilities and shows how these major facilities are organized by program elements. Section II gives a more detailed breakdown of the over 200 research and technology facilities being used at the Laboratories to support the Defense Programs mission.

Biomechanical evaluation of a spherical lumbar interbody device at varying levels of subsidence.

Science.gov (United States)

Rundell, Steven A; Isaza, Jorge E; Kurtz, Steven M

2011-01-01

Ulf Fernström implanted stainless steel ball bearings following discectomy, or for painful disc disease, and termed this procedure disc arthroplasty. Today, spherical interbody spacers are clinically available, but there is a paucity of associated biomechanical testing. The primary objective of the current study was to evaluate the biomechanics of a spherical interbody implant. It was hypothesized that implantation of a spherical interbody implant, with combined subsidence into the vertebral bodies, would result in similar ranges of motion (RoM) and facet contact forces (FCFs) when compared with an intact condition. A secondary objective of this study was to determine the effect of using a polyetheretherketone (PEEK) versus a cobalt chrome (CoCr) implant on vertebral body strains. We hypothesized that the material selection would have a negligible effect on vertebral body strains since both materials have elastic moduli substantially greater than the annulus. A finite element model of L3-L4 was created and validated by use of ROM, disc pressure, and bony strain from previously published data. Virtual implantation of a spherical interbody device was performed with 0, 2, and 4 mm of subsidence. The model was exercised in compression, flexion, extension, axial rotation, and lateral bending. The ROM, vertebral body effective (von Mises) strain, and FCFs were reported. Implantation of a PEEK implant resulted in slightly lower strain maxima when compared with a CoCr implant. For both materials, the peak strain experienced by the underlying bone was reduced with increasing subsidence. All levels of subsidence resulted in ROM and FCFs similar to the intact model. The results suggest that a simple spherical implant design is able to maintain segmental ROM and provide minimal differences in FCFs. Large areas of von Mises strain maxima were generated in the bone adjacent to the implant regardless of whether the implant was PEEK or CoCr.

Radon Research Program, FY 1992

International Nuclear Information System (INIS)

1993-04-01

The United States Department of Energy, Office of Health and Environmental Research (DOE/OHER) is the principal federal agency conducting basic research related to indoor radon. The scientific information being sought in this program encompasses research designed to determine radon availability and transport outdoors, modeling transport into and within buildings, physics and chemistry of radon and radon progeny, dose response relationships, lung cancer risk, and mechanisms of radon carcinogenesis. There still remains a significant number of uncertainties in the currently available knowledge that is used to estimate lung cancer risk from exposure to environmental levels of radon and its progeny. The main goal of the DOE/OHER Radon Research Program is to develop information to reduce these uncertainties and thereby provide an improved health risk estimate of exposure to radon and its progeny and to identify and understand biological mechanisms of lung cancer development and required copollutants at low levels of exposure. Information useful in radon control strategies is also provided by the basic science undertaken in this program

Decontamination Systems Information and Research Program

International Nuclear Information System (INIS)

Berg, M.; Sack, W.A.; Gabr, M.

1994-01-01

The Decontamination Systems Information and Research Program at West Virginia University consists of research and development associated with hazardous waste remediation problems at the Department of Energy complex and elsewhere. This program seeks to facilitate expedited development and implementation of solutions to the nation's hazardous waste clean-up efforts. By a unique combination of university research and private technology development efforts, new paths toward implementing technology and speeding clean-ups are achievable. Mechanisms include aggressive industrial tie-ins to academic development programs, expedited support of small business technology development efforts, enhanced linkages to existing DOE programs, and facilitated access to hazardous waste sites. The program topically falls into an information component, which includes knowledge acquisition, technology evaluation and outreach activities and an R and D component, which develops and implements new and improved technologies. Projects began in February 1993 due to initiation of a Cooperative Agreement between West Virginia University and the Department of Energy

Why do adults entitled to free or highly subsidized dental services select fully out-of-pocket-paid care?

Science.gov (United States)

Bayat, Fariborz; Vehkalahti, Miira M; Murtomaa, Heikki; Tala, Heikki

2010-02-01

To investigate patients' reasons for selecting a dental clinic given their choice of free or highly-subsidized dental services. The study was based on cross-sectional data obtained through phone interviews with adults in Tehran, Iran. The present study included those entitled to free or highly-subsidized dental services (n = 726). The data covered the patients' awareness of subsidized dental services and type of dental clinic for their most recent visit and their reasons for selecting that clinic. Awareness of subsidized dental services was dichotomized as being either aware or unaware of such subsidy. The type of clinic was dichotomized as providing either free or highly-subsidized (FHS) or fully out-of-pocket paid (FOP) services. Free format answers about the subjects' reasons for selecting a particular clinic were later sub-grouped as: convenient access, good technical aspects, good interpersonal aspects, low or reasonable fees, recommendation by a friend, and no reason. Socio-demographic status was based on background. Data analysis included the chi-square test and logistic regression model. Of the subjects (n = 726), 60% were women and 58% were under 35 years of age. The subjects' mean age was 33.5 years with no difference by gender (P = 0.24) and the majority had public insurance (91%). Of all the subjects, 60% selected FOP. Good interpersonal aspects were the strongest reason for selecting FOP (OR = 4.6), follow by good technical aspects (OR = 2.3). Those subjects who were unaware of their benefit had 4.6 times the odds of selecting FOP. Despite the opportunity to use highly-subsidized dental services, good interpersonal and good technical aspects lead patients to select private dentists and to pay fully out of pocket.

Water reactor safety research program. A description of current and planned research

International Nuclear Information System (INIS)

1978-07-01

The U.S. Nuclear Regulatory Commission (NRC) sponsors confirmatory safety research on lightwater reactors in support of the NRC regulatory program. The principal responsibility of the NRC, as implemented through its regulatory program is to ensure that public health, public safety, and the environment are adequately protected. The NRC performs this function by defining conditions for the use of nuclear power and by ensuring through technical review, audit, and follow-up that these conditions are met. The NRC research program provides technical information, independent of the nuclear industry, to aid in discharging these regulatory responsibilities. The objectives of NRC's research program are the following: (1) to maintain a confirmatory research program that supports assurance of public health and safety, and public confidence in the regulatory program, (2) to provide objectively evaluated safety data and analytical methods that meet the needs of regulatory activities, (3) to provide better quantified estimates of the margins of safety for reactor systems, fuel cycle facilities, and transportation systems, (4) to establish a broad and coherent exchange of safety research information with other Federal agencies, industry, and foreign organization. Current and planned research toward these goals is described

Nursing research programs gather strength in Australia.

Science.gov (United States)

Borbasi, Sally; Emden, Carolyn; Jackson, Debra

2005-04-01

To shed light on programmatic research through direct experience is highly beneficial to nursing scholarship. Following a recent description of a successful Australian program of research centered around people's chronic illness experience we are inspired to continue the commentary (Koch et al 2005). Koch et al's (2005) case study reported on several 'core elements' they believe have contributed to the growth and effectiveness of their program. In this paper we consider some of these in light of current literature and our own challenging experiences within several Australian universities. Koch et al (2005) also makes a not too subtle distinction between dedicated research units independent of universities and research programs emanating from academia, suggesting the former are more productive. While one of the authors in the above paper, a UK scholar and nursing academic, makes interesting observations about this assertion, we contend that his UK perspective fails to capture the urgency of establishing nursing research programs in Australian universities. Consequently, we have chosen to extend the discussion about nursing research programs from the perspective of Australian academe, including comment on building productive relationships, strengthening a track record, research and practice as symbiotic processes, competitive funding strategies, and the integral role of research students. The entire commentary is located in a celebratory context of 20 years of Australian nursing education in the university sector, a context not without controversy. We give consideration to the best way ahead for the future of nursing research programs and hope our ideas spark further sharing of experiences.

Program of research 1988-89

International Nuclear Information System (INIS)

1988-08-01

From 1 July 1988, the research activities of ANSTO have reorganised into five programs: advanced materials; applications of nuclear physics; environmental science; applications of radioisotopes and radiation; biomedicine and health. This structure not only groups the main research activities but also identifies the underpinning of ANSTO's commercial activities. This document describes the projects to be undertaken in the 1988-89 financial year. Each project in a particular program area is defined in terms of background, objective, recent work and achievements, work planned, resources and the project manager is identified. Research is also undertaken in areas of the operational activities of the organisation and these also are detailed

Program Leader | IDRC - International Development Research Centre

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

Leads in the identification of the overall development research ... Ensures that a regional perspective is brought to bear on program planning at the PI and ... The incumbent is the manager of the Program Initiative program and team and as such: ... projects between Canadian and developing country researchers; and; When ...

Subsidence due to gas production in the Wadden Sea: How to ensure no harm will be done to nature

NARCIS (Netherlands)

Thienen-Visser, K. van; Breunese, J.N.; Muntendam-Bos, A.G.

2015-01-01

The Wadden Sea is a shallow tidal sea in the north of the Netherlands where gas production is ongoing since 1986. Due to the sensitive nature of this area, gas extraction induced subsidence must remain within the "effective subsidence capacity" for the two tidal basins (Pinkegat and Zoutkamperlaag)

Coastal city subsidence in Shenzhen (China), monitored using multi-frequency radar interferometry time-series techniques

Science.gov (United States)

Liu, Peng; Li, Yongsheng; Singleton, Andrew; Li, Qingquan; Zhang, Jingfa; Li, Zhenhong

2014-05-01

In just 26 years, the coastal city of Shenzhen (Southern China) has been transformed from a small fishing village to a modern city with a population exceeding 8.5 million people. Following its designation as a Special Economic Zone in the 1980s, the city became a test bed for China's economic reforms and currently leads many new practices in urban planning. The rapid economic development was matched by a sharp increase in the demand for usable land and consequently, extensive coastal reclamation has been undertaken by piling rock fragments from nearby hills onto the seabed. However, it has recently been reported that new apartments, offices and transport networks built on the reclaimed land have become unusable due to ground subsidence. The additional threat of coastal inundation from sea-level rise also requires serious consideration. InSAR time-series techniques (such as Persistent Scatterer and Small Baseline InSAR) are capable of detecting sub-centimetre elevation changes of the Earth's surface over large areas and at a density far exceeding the capabilities of a GPS network - particularly for such an urban environment as Shenzhen. This study uses numerous independent tracks of SAR data (two ENVISAT C-band tracks and two ALOS L-band tracks) to determine the surface movements between 2004 and 2013. Quantitative comparative analyses are carried out in the overlapping area between two adjacent tracks, and thus no ground data is required to validate InSAR results. The results show greatest subsidence in coastal areas with the areas of reclaimed land also predominantly undergoing subsidence. The combination of different ascending and descending tracks allows 2D velocity fields to be estimated and it will be important to determine whether the subsidence from the recently reclaimed land is consolidation or part of a longer-term trend. This ability to provide accurate measurements of ground stability for the city of Shenzhen will help focus investigations into areas of

Teacher Research Programs = Increased Student Achievement

Science.gov (United States)

Dubner, J.

2011-12-01

Columbia University's Summer Research Program for Science Teachers (SRP), founded in 1990, is one of the largest, best known university professional development programs for science teachers in the U.S. For eight weeks in each of two consecutive summers, teachers participate as a member of a research team, led by a member of Columbia University's research faculty. In addition to the laboratory experience, all teachers meet weekly during the summer for a series of pedagogical activities to assist them in transferring the experience to their classrooms. The primary goal of the program is to provide K-12 science teachers with opportunities to work at the cutting edge of science and engineering, and thus to revitalize their teaching and help them to appreciate the use of inquiry-based methods in their classroom instruction. The secondary goals of the program are to give the pre-college teacher the ability to guide their students toward careers in science and engineering, to develop new teaching strategies, and to foster long-term scholarly collaborations. The last is especially important as it leads to a model of the teacher as active in science yet committed to the pre-college classroom. Since its inception, SRP has focused on an objective assessment of the program's impact on attitudes and instructional practices of participating teachers, on the performance of these teachers in their mentors' laboratories, and most importantly, on the impact of their participation in the program has on student interest and performance in science. Our research resulted in a paper published in the journal Science. SRP also facilitates a multi-site survey-based evaluation of other teacher research programs around the country. The author will present the findings of both studies.

What Is the Economic Burden of Subsidized HIV/AIDS Treatment Services on Patients in Nigeria and Is This Burden Catastrophic to Households?

Directory of Open Access Journals (Sweden)

Enyi Etiaba

Full Text Available A gap in knowledge exists regarding the economic burden on households of subsidized anti-retroviral treatment (ART programs in Nigeria. This is because patients also incur non-ART drug costs, which may constrain the delivery and utilisation of subsidized services.An exit survey of adults (18+years attending health facilities for HIV/AIDS treatment was conducted in three states in Nigeria (Adamawa, Akwa Ibom and Anambra. In the states, ART was fully subsidized but there were different payment modalities for other costs of treatment. Data was collected and analysed for direct and indirect costs of treatment of HIV/AIDS and co-morbidities' during out-and in-patient visits. The levels of catastrophic health expenditure (CHE were computed and disaggregated by state, socio-economic status (SES and urban-rural location of the respondents. Catastrophic Health Expenditure (CHE in this study measures the number of respondents whose monthly ART-related household expenditure (for in-patient and out-patient visits as a proportion of monthly non-food expenditure was greater than 40% and 10% respectively.The average out-patient and in-patient direct costs were $5.49 and $122.10 respectively. Transportation cost was the highest non-medical cost and it was higher than most medical costs. The presence of co-morbidities contributed to household costs. All the costs were catastrophic to households at 10% and 40% thresholds in the three states, to varying degrees. The poorest SES quintile had the highest incidence of CHE for out-patient costs (p<0.0001. Rural dwellers incurred more CHE for all categories of costs compared to urban dwellers, but the costs were statistically significant for only outpatient costs.ART subsidization is not enough to eliminate economic burden of treatment on HIV patients. Service decentralization to reduce travel costs, and subsidy on other components of HIV treatment services should be introduced to eliminate the persisting inequitable

Role of EPA in Asset Management Research – The Aging Water Infrastructure Research Program

Science.gov (United States)

This slide presentation provides an overview of the EPA Office of Research and Development’s Aging Water infrastructure Research Program (AWIRP). The research program origins, goals, products, and plans are described. The research program focuses on four areas: condition asses...

Subsidized childcare and child development in Colombia: effects of Hogares Comunitarios de Bienestar as a function of timing and length of exposure.

Science.gov (United States)

Bernal, Raquel; Fernández, Camila

2013-11-01

Rigorous evidence regarding the impact of early care and education on children's development comes primarily from high-income nations. A few studies from Latin America and the Caribbean have identified benefits of conditional cash transfer and home visiting programs on children's development. However, there is still controversy around the impact and cost-effectiveness of childcare approaches. Further research is needed to understand how scaled-up childcare settings may support the development of low-income children in Latin America. To that end, the present study sought to identify the effects of exposure to a subsidized childcare program in Colombia on children's nutritional status, cognitive and socioemotional development. This community-based program, known as Hogares Comunitarios de Bienestar (HCB), serves 800 thousand low-income children under age 6, delivering home-based childcare, supplementary nutrition, and psychosocial stimulation. We analyzed data on 10,173 program beneficiary children (ages 3-6) collected in 2007. We compared beneficiary children who had been in the program for a long time with beneficiary children who had been in the program for a month or less, by age group, to estimate program exposure effects. We used a matching estimator to correct for self-selection into different exposure levels. Results indicated that cognitive development improved 0.15 to 0.3 of a standard deviation (SD) after at least 15 months of exposure for children between 3 and 6 years of age. Socioemotional skills improved 0.12 to 0.3 SD for children older than 3 after at least 15 months of program exposure. No significant gains were found for nutritional status. The estimated benefit-cost ratio ranged from 1.0 to 2.7, depending upon varying discount rates. Findings lend support for a potentially effective strategy to promote the development of low-income children in Colombia and other developing nations. Copyright © 2012 Elsevier Ltd. All rights reserved.

Use of Cemented Super-Fine Unclassified Tailings Backfill for Control of Subsidence

Directory of Open Access Journals (Sweden)

Lei Yang

2017-11-01

Full Text Available Known for its advantages in preventing geological and environmental hazards, cemented paste backfill (CPB has become a topic of interest for scientists and mining engineers in recent decades. This paper presents the results of a study on the use of cemented super-fine tailings backfill (CSUTB in an underground mine for control of surface subsidence. An analytical solution is developed based on the available model to calculate the required strength of backfill when in contact with non-cemented tailings (NCT. The effect of solid contents on the rheological properties of CSUTB is investigated. A reasonable mix proportion (RMP of CSUTB is determined for Zhongguan Iron Mine (ZGIM based on laboratory experiments. The validity of RMP in surface subsidence control is verified by a 3D numerical model. The obtained results show that CSUTB requires higher strength when in contact with NCT than when in contact with orebody. Rheological characteristics, e.g., slump, fluidity, and bleeding rate of fresh CSUTB, decrease with higher solids content, of which values with a certain solids content can be determined by quadratic polynomial regression equations. RMP with a cement to tailings (c/t ratio of 1:10 and a solids content of 70% is recommended for ZGIM, as it shows favorable mechanical and rheological abilities. The deformation parameters (curvature, inclination, and horizontal deformation rate obtained from numerical modeling are acceptable and lower than critical values, meaning CSUTB can feasibly be used with RMP in subsidence control.

Threat of land subsidence in and around Kolkata City and East ...

Indian Academy of Sciences (India)

ile wetland to minimize the adverse environmental impacts of groundwater development. This study, for the first time, indicates the threat of possible land subsidence due to unrestricted groundwater abstraction in the EKW and also out- lines a groundwater management plan for sustain- able development of groundwater in ...

Mass movement processes triggered by land subsidence in Iztapalapa, the eastern part of Mexico City

Directory of Open Access Journals (Sweden)

M. González-Hernández

2015-11-01

Full Text Available Geological and structural conditions in the Basin of Mexico coupled with natural and anthropogenic factors, such as groundwater exploitation, provokes land subsidence and differential deformation. The study area is located in to the north of Iztapalapa, a municipality within Mexico City, in a site called "El Eden" with irregular topography. Where volcanic sequences overlie the lacustrine deposits of clays and silts and show displacements by the action of gravity. The displacement zone was delimited at the top of the slope by the formation of circular tensile fractures with stair -shaped geometries. At the base of the slope, compressive processes damaged housing, sidewalks and inclined light poles and trees. A NW-SE system of fractures was identified in which displacement velocities vary from a few millimeters to several centimeters per year. Which affects urban facilities. In this work a conceptual model of deformation is presented that integrates the geological and mechanical factors leading to landslide and land subsidence. A geophysical survey leads to evidence of how land subsidence processes increase the sliding slope.

Summer Undergraduate Research Program: Environmental studies

Energy Technology Data Exchange (ETDEWEB)

McMillan, J. [ed.

1994-12-31

The purpose of the summer undergraduate internship program for research in environmental studies is to provide an opportunity for well-qualified students to undertake an original research project as an apprentice to an active research scientist in basic environmental research. The students are offered research topics at the Medical University in the scientific areas of pharmacology and toxicology, epidemiology and risk assessment, environmental microbiology, and marine sciences. Students are also afforded the opportunity to work with faculty at the University of Charleston, SC, on projects with an environmental theme. Ten well-qualified students from colleges and universities throughout the eastern United States were accepted into the program.

Development of an expert analysis tool based on an interactive subsidence hazard map for urban land use in the city of Celaya, Mexico

Science.gov (United States)

Alloy, A.; Gonzalez Dominguez, F.; Nila Fonseca, A. L.; Ruangsirikulchai, A.; Gentle, J. N., Jr.; Cabral, E.; Pierce, S. A.

2016-12-01

Land Subsidence as a result of groundwater extraction in central Mexico's larger urban centers initiated in the 80's as a result of population and economic growth. The city of Celaya has undergone subsidence for a few decades and a consequence is the development of an active normal fault system that affects its urban infrastructure and residential areas. To facilitate its analysis and a land use decision-making process we created an online interactive map enabling users to easily obtain information associated with land subsidence. Geological and socioeconomic data of the city was collected, including fault location, population data, and other important infrastructure and structural data has been obtained from fieldwork as part of a study abroad interchange undergraduate course. The subsidence and associated faulting hazard map was created using an InSAR derived subsidence velocity map and population data from INEGI to identify hazard zones using a subsidence gradient spatial analysis approach based on a subsidence gradient and population risk matrix. This interactive map provides a simple perspective of different vulnerable urban elements. As an accessible visualization tool, it will enhance communication between scientific and socio-economic disciplines. Our project also lays the groundwork for a future expert analysis system with an open source and easily accessible Python coded, SQLite database driven website which archives fault and subsidence data along with visual damage documentation to civil structures. This database takes field notes and provides an entry form for uniform datasets, which are used to generate a JSON. Such a database is useful because it allows geoscientists to have a centralized repository and access to their observations over time. Because of the widespread presence of the subsidence phenomena throughout cities in central Mexico, the spatial analysis has been automated using the open source software R. Raster, rgeos, shapefiles, and rgdal

International Research and Studies Program

Science.gov (United States)

Office of Postsecondary Education, US Department of Education, 2012

2012-01-01

The International Research and Studies Program supports surveys, studies, and instructional materials development to improve and strengthen instruction in modern foreign languages, area studies, and other international fields. The purpose of the program is to improve and strengthen instruction in modern foreign languages, area studies and other…

Sandia Combustion Research Program

Energy Technology Data Exchange (ETDEWEB)

Johnston, S.C.; Palmer, R.E.; Montana, C.A. (eds.)

1988-01-01

During the late 1970s, in response to a national energy crisis, Sandia proposed to the US Department of Energy (DOE) a new, ambitious program in combustion research. Shortly thereafter, the Combustion Research Facility (CRF) was established at Sandia's Livermore location. Designated a ''user facility,'' the charter of the CRF was to develop and maintain special-purpose resources to support a nationwide initiative-involving US inventories, industry, and national laboratories--to improve our understanding and control of combustion. This report includes descriptions several research projects which have been simulated by working groups and involve the on-site participation of industry scientists. DOE's Industry Technology Fellowship program, supported through the Office of Energy Research, has been instrumental in the success of some of these joint efforts. The remainder of this report presents results of calendar year 1988, separated thematically into eleven categories. Referred journal articles appearing in print during 1988 and selected other publications are included at the end of Section 11. Our traditional'' research activities--combustion chemistry, reacting flows, diagnostics, engine and coal combustion--have been supplemented by a new effort aimed at understanding combustion-related issues in the management of toxic and hazardous materials.

IMPACT OF OIL ON THE MECHANICAL PROPERTIES OF SOIL SUBSIDENCE

Directory of Open Access Journals (Sweden)

Алексей Алексеевич Бурцев

2016-08-01

Full Text Available The paper studied the effect of oil content on the mechanical properties of soil subsidence - Ek modulus and compressibility factor m0, obtained in the laboratory with the help of artificial impregnation oil soil samples. A comparison of the above parameters with samples of the same soil in the natural and water-saturated conditions has been perfomed.

Estimation of surface subsidence at the Waste Isolation Pilot Plant

International Nuclear Information System (INIS)

Givens, C.A.; Valdivia, M.A.; Saeb, S.; Francke, C.T.; Patchet, S.J.

1995-01-01

Subsidence effects at the WIPP site wee estimated using numerical methods as well as the influence function method and NCB method because single universally accepted method is not available for salt. The use of parallel methods and the agreement between their results greatly enhanced the confidence in the analysis because the prediction would not depend on the assumptions inherent in a single method

Experimental analysis of the effect of taxes and subsides on calories purchased in an on-line supermarket.

Science.gov (United States)

Epstein, Leonard H; Finkelstein, Eric; Raynor, Hollie; Nederkoorn, Chantal; Fletcher, Kelly D; Jankowiak, Noelle; Paluch, Rocco A

2015-12-01

Taxes and subsidies are a public health approach to improving nutrient quality of food purchases. While taxes or subsidies influence purchasing, it is unclear whether they influence total energy or overall diet quality of foods purchased. Using a within subjects design, selected low nutrient dense foods (e.g. sweetened beverages, candy, salty snacks) were taxed, and fruits and vegetables and bottled water were subsidized by 12.5% or 25% in comparison to a usual price condition for 199 female shoppers in an experimental store. Results showed taxes reduced calories purchased of taxed foods (coefficient = -6.61, CI = -11.94 to -1.28) and subsidies increased calories purchased of subsidized foods (coefficient = 13.74, CI = 8.51 to 18.97). However, no overall effect was observed on total calories purchased. Both taxes and subsidies were associated with a reduction in calories purchased for grains (taxes: coefficient = -6.58, CI = -11.91 to -1.24, subsidies: coefficient = -12.86, CI = -18.08 to -7.63) and subsidies were associated with a reduction in calories purchased for miscellaneous foods (coefficient = -7.40, CI = -12.62 to -2.17) (mostly fats, oils and sugars). Subsidies improved the nutrient quality of foods purchased (coefficient = 0.14, CI = 0.07 to 0.21). These results suggest that taxes and subsidies can influence energy purchased for products taxed or subsidized, but not total energy purchased. However, the improvement in nutrient quality with subsidies indicates that pricing can shift nutritional quality of foods purchased. Research is needed to evaluate if differential pricing strategies based on nutrient quality are associated with reduction in calories and improvement in nutrient quality of foods purchased. Copyright © 2015 Elsevier Ltd. All rights reserved.

Investigation of land subsidence in the Houston-Galveston region of Texas by using the Global Positioning System and interferometric synthetic aperture radar, 1993-2000

Science.gov (United States)

Bawden, Gerald W.; Johnson, Michaela R.; Kasmarek, Mark C.; Brandt, Justin; Middleton, Clifton S.

2012-01-01

Since the early 1900s, groundwater has been the primary source of municipal, industrial, and agricultural water supplies for the Houston-Galveston region, Texas. The region's combination of hydrogeology and nearly century-long use of groundwater has resulted in one of the largest areas of subsidence in the United States; by 1979, as much as 3 meters (m) of subsidence had occurred, and approximately 8,300 square kilometers of land had subsided more than 0.3 m. The U.S. Geological Survey, in cooperation with the Harris-Galveston Subsidence District, used interferometric synthetic aperture radar (InSAR) data obtained for four overlapping scenes from European remote sensing satellites ERS-1 and ERS-2 to analyze land subsidence in the Houston-Galveston region of Texas. The InSAR data were processed into 27 interferograms that delineate and quantify land-subsidence patterns and magnitudes. Contemporaneous data from the Global Positioning System (GPS) were reprocessed by the National Geodetic Survey and analyzed to support, verify, and provide temporal resolution to the InSAR investigation.

Impact of the Surgical Research Methodology Program on surgical residents' research profiles.

Science.gov (United States)

Farrokhyar, Forough; Amin, Nalin; Dath, Deepak; Bhandari, Mohit; Kelly, Stephan; Kolkin, Ann M; Gill-Pottruff, Catherine; Skot, Martina; Reid, Susan

2014-01-01

To evaluate whether implementing the formal Surgical Research Methodology (SRM) Program in the surgical residency curriculum improved research productivity compared with the preceding informal Research Seminar Series (RSS). The SRM Program replaced the RSS in July 2009. In the SRM Program, the curriculum in Year-1 consisted of 12 teaching sessions on the principles of clinical epidemiology and biostatistics, whereas the focus in Year-2 was on the design, conduct, and presentation of a research project. The RSS consisted of 8 research methodology sessions repeated annually for 2 years along with the design, conduct, and presentation of a research project. Research productivity was measured as the number of peer-reviewed publications and the generation of studies with higher levels of evidence. Outcome measures were independently assessed by 2 authors to avoid bias. Student t test and chi-square test were used for the analysis. Frequencies, mean differences with 95% CI, and effect sizes have been reported. In this study, 81 SRM residents were compared with 126 RSS residents. The performance of the SRM residents was superior on all metrics in our evaluation. They were significantly more productive and published more articles than the RSS residents (mean difference = 1.0 [95% CI: 0.5-1.5], p research performance improved 11.0 grades (95% CI: 8.5%-13.5%, p research methodology is crucial to appropriately apply evidence-based findings in clinical practice. The SRM Program has significantly improved the research productivity and performance of the surgical residents from all disciplines. The implementation of a similar research methodology program is highly recommended for the benefit of residents' future careers and ultimately, evidence-based patient care. Copyright © 2014 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

Taphonomic expressions of sedimentary hiatuses: field observations on bioclastic concentrations and sequence anatomy in low, moderate and high subsidence settings

Science.gov (United States)

Kidwell, S. M.

1993-07-01

Field studies of post-Palaeozoic siliciclastic records reveal a strong concordance between different types of bioclastic concentrations and discontinuity surfaces within third-order sequences (≈ 1 My duration), supporting the use of taphonomic criteria in establishing the relative magnitudes of sedimentary hiatuses. Comparison of records across a spectrum of subsidence rates, however (from ≤ 10 m to > 1 km/My), shows that, along with appreciable changes in sequence anatomy, the nature of surface-mantling bioclastic concentrations also changes. The most significant surfaces (second- and third-order sequence boundaries, surfaces or intervals of maximum transgression, transgressive surfaces) tend to be either bare or mantled with taphonomically complex hiatal and lag concentrations. These were more consistently encountered in low subsidence than in moderate subsidence records. In high subsidence records, major surfaces were more often mantled by composite or event concentrations, if they were bioclastic at all. In all subsidence settings, comparatively minor surfaces (parasequence boundaries, bed set boundaries and bedding planes) were bare or mantled with relatively simple event and composite concentrations. Although all fossil assemblages are biased taphonomically to some degree, relative degrees of bias should almost certainly vary among discontinuities as a general rule, suggesting specific adjustments in sampling strategies for evolutionary studies.

E-Area Low-Level Waste Facility Vadose Zone Model: Confirmation of Water Mass Balance for Subsidence Scenarios

Energy Technology Data Exchange (ETDEWEB)

Dyer, J. A. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2017-11-30

In preparation for the next revision of the E-Area Low-Level Waste Facility (LLWF) Performance Assessment (PA), a mass balance model was developed in Microsoft Excel to confirm correct implementation of intact- and subsided-area infiltration profiles for the proposed closure cap in the PORFLOW vadose-zone model. The infiltration profiles are based on the results of Hydrologic Evaluation of Landfill Performance (HELP) model simulations for both intact and subsided cases.

University Research Consortium annual review meeting program

International Nuclear Information System (INIS)

1996-07-01

This brochure presents the program for the first annual review meeting of the University Research Consortium (URC) of the Idaho National Engineering Laboratory (INEL). INEL is a multiprogram laboratory with a distinctive role in applied engineering. It also conducts basic science research and development, and complex facility operations. The URC program consists of a portfolio of research projects funded by INEL and conducted at universities in the United States. In this program, summaries and participant lists for each project are presented as received from the principal investigators

University Research Consortium annual review meeting program

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-07-01

This brochure presents the program for the first annual review meeting of the University Research Consortium (URC) of the Idaho National Engineering Laboratory (INEL). INEL is a multiprogram laboratory with a distinctive role in applied engineering. It also conducts basic science research and development, and complex facility operations. The URC program consists of a portfolio of research projects funded by INEL and conducted at universities in the United States. In this program, summaries and participant lists for each project are presented as received from the principal investigators.

Peat subsidence and its practical implications: a case study in Malaysia

NARCIS (Netherlands)

Wösten, J.H.M.; Ismail, A.B.; Wijk, van A.L.M.

1997-01-01

Due to pressure for land, substantial areas of peat swamps in South-East Asia have been and presently are being reclaimed for agriculture or for other land use. As soon as peat swamps are drained, the irreversible process of subsidence starts, which can only be stopped by waterlogging the peat

FY 1995 research highlights: PNL accomplishments in OER programs

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-10-01

Pacific Northwest Laboratory (PNL) conducts fundamental and applied research in support of the US Department of Energy`s (DOE) core missions in science and technology, environmental quality, energy resources, and national security. Much of this research is funded by the program offices of DOE`s Office of Energy Research (DOE-ER), primarily the Office of Basic Energy Sciences (BES) and the Office of Health and Environmental Research (OHER), and by PNL`s Laboratory Directed Research and Development (LDRD) Program. This document is a collection of research highlights that describe PNL`s accomplishments in DOE-ER funded programs during Fiscal Year 1995. Included are accomplishments in research funded by OHER`s Analytical Technologies, Environmental Research, Health Effects, General Life Sciences, and Carbon Dioxide Research programs; BES`s Materials Science, Chemical Sciences, Engineering and Geoscience, and Applied Mathematical Sciences programs; and PNL`s LDRD Program. Summaries are given for 70 projects.

Environmental Biotechnology Research and Development Program 1989-1992

OpenAIRE

Brinkman J; Rulkens WH; Visscher K

1989-01-01

This report is an English translation of the Dutch Research and Development Program on environmental biotechnology 1989-1992. In this program an overview is given of the recent developments in environmental biotechnology. Based on this overview, the possibilities of biotechnology for management of the environment are evaluated. In this program two kinds of research are distinguished. Applied research directly focusses on specific environmental problems. Fundamental research aims at developing...

Defense Nanotechnology Research and Development Program

National Research Council Canada - National Science Library

2007-01-01

...), Army Research Office (ARO) and the Air Force Office of Scientific Research (AFOSR)initiated numerous research and development programs focusing on advancing science and technology below one micron in size...

Summary of entire research achievements of creative engineering research program on nuclear fuel cycle

International Nuclear Information System (INIS)

Takenaka, Shingo; Ikegami, Tetsuo

2008-03-01

Creative Engineering Research Program on Nuclear Fuel Cycle (former In-house Innovative Research Encouraging Program) was implemented from FY 2001 to FY 2007 in order to support such in-house researches that create innovative new concepts and aim technical break-through. Totally 37 applications have been received and 14 research themes have been accepted and been performed in this program. As for the research achievements of the 14 research themes, first author papers accepted by scientific journals and by science councils were 47 and 32, respectively, and oral presentations at scientific societies were 99. Furthermore, interpretive articles for scientific journals, requested lectures, patents, and prize winnings were 13, 30, 8, and 3, respectively. Consequently, it can be evaluated that the research achievements resulted from this program are generally in high level and that the expectations, at the starting point of this program, to activate the innovative research activities have been accomplished. In this report, the final reports of the 14 research themes together with the outline of this program are included. (author)

Contributions of a Strengthened Early Holocene Monsoon and Sediment Loading to Present-Day Subsidence of the Ganges-Brahmaputra Delta

Science.gov (United States)

Karpytchev, M.; Ballu, V.; Krien, Y.; Becker, M.; Goodbred, S.; Spada, G.; Calmant, S.; Shum, C. K.; Khan, Z.

2018-02-01

The contribution of subsidence to relative sea level rise in the Ganges-Brahmaputra delta (GBD) is largely unknown and may considerably enhance exposure of the Bengal Basin populations to sea level rise and storm surges. This paper focuses on estimating the present-day subsidence induced by Holocene sediment in the Bengal Basin and by oceanic loading due to eustatic sea level rise over the past 18 kyr. Using a viscoelastic Earth model and sediment deposition history based on in situ measurements, results suggest that massive sediment influx initiated in the early Holocene under a strengthened South Asian monsoon may have contributed significantly to the present-day subsidence of the GBD. We estimate that the Holocene loading generates up to 1.6 mm/yr of the present-day subsidence along the GBD coast, depending on the rheological model of the Earth. This rate is close to the twentieth century global mean sea level rise (1.1-1.7 mm/yr). Thus, past climate change, by way of enhanced sedimentation, is impacting vulnerability of the GBD populations.

Late carboniferous foreland basin formation and Early Carboniferous stretching in Northwestern Europe: Inferences from quantitative subsidence analyses in the Netherlands

NARCIS (Netherlands)

Kombrink, H.; Leever, K.A.; Wees, J.-D. van; Bergen, F. van; David, P.; Wong, T.E.

2008-01-01

The large thickness of Upper Carboniferous strata found in the Netherlands suggests that the area was subject to long-term subsidence. However, the mechanisms responsible for subsidence are not quantified and are poorly known. In the area north of the London Brabant Massif, onshore United Kingdom,

[Research within the reach of Osakidetza professionals: Primary Health Care Research Program].

Science.gov (United States)

Grandes, Gonzalo; Arce, Verónica; Arietaleanizbeaskoa, María Soledad

2014-04-01

To provide information about the process and results of the Primary Health Care Research Program 2010-2011 organised by the Primary Care Research Unit of Bizkaia. Descriptive study. Osakidetza primary care. The 107 health professionals who applied for the program from a total of 4,338 general practitioners, nurses and administrative staff who were informed about it. Application level, research topics classification, program evaluation by participants, projects funding and program costs. Percentage who applied, 2.47%; 95% CI 2.41-2.88%. Of the 28 who were selected and 19 completed. The research topics were mostly related to the more common chronic diseases (32%), and prevention and health promotion (18%). Over 90% of participants assessed the quality of the program as good or excellent, and half of them considered it as difficult or very difficult. Of the18 new projects generated, 12 received funding, with 16 grants, 10 from the Health Department of the Basque Government, 4 from the Carlos III Institute of Health of the Ministry of Health of Spain, and 2 from Kronikgune. A total of €500,000 was obtained for these projects. This program cost €198,327. This experience can be used by others interested in the promotion of research in primary care, as the program achieved its objectives, and was useful and productive. Copyright © 2013 Elsevier España, S.L. All rights reserved.

Characterizing land subsidence mechanisms as a function of urban basin geohazards using space geodesy

Science.gov (United States)

Bawden, G. W.

2016-12-01

Land subsidence in urban basins will likely become a more significant geohazard in many of the global sedimentary basins as population growth, resource availability, and climate change compound natural and anthropogenic contributors that influence basin elevation. Coastal basins are at the greatest risk where land subsidence is additive to sea level rise, thereby increasing the rate of exposure to coastal populations. Land surface elevation change is a function of many different parameters, including: elastic and inelastic surface response to managed and natural groundwater levels; anthropogenic activities (hydrocarbon extraction, wastewater injection, fracking, geothermal production, and mass redistribution); local tectonic deformation and regional tectonic drivers (such as repeated uplift and subsidence cycles above subduction zones); climate change (influencing the timing, magnitude, nature and duration of seasonal/annual precipitation and permafrost extent); material properties of the basin sediments (influencing susceptibility to soil compaction, oxidization, and dissolution); post glacial rebound; isostatic flexure associated with sea-level and local mass changes; and large scale gravitational processes (such as growth faults and landslides). Geodetic measurements, such as InSAR and GPS, help track spatial and temporal changes in both relative and absolute basin elevation thereby helping to characterize the mechanism(s) driving the geohazards. In addition to a number of commercial radar satellites, European Space Agency's Sentinel-1a/b satellites are beginning to provide a wealth of data over many basin targets with C-band (5.5 cm wavelength). The NISAR (NASA-ISRO Synthetic Aperture Radar) L-band (24 cm wavelength) mission (anticipated 2021 launch) will image nearly every basin globally every 12 days and data from the mission will help characterize land subsidence and many other solid-Earth and hydrologic geohazards that impact urban basins.

Housing building with steel framing system in subsidence zones: Pertinence and Sustainability

Directory of Open Access Journals (Sweden)

Luis Alfredo Hernádez Castillo

2014-04-01

Full Text Available The phenomenon of subsidence caused by the extraction of groundwater is a problem that occurs in different places around the world. Particularly in the Mexican Republic is a situation that affects several cities in at least eight states located in the central region. Given the particular nature of the subsoil that occurs in these regions affected, subsidence can generate cracks and fractures that are evident on the surface of the soil causing differential settlement affecting all types of construction causing considerable damage to the structural elements of the dwellings. The materials traditionally used for housing construction such as masonry and concrete among others, have stiffness characteristics that make them especially vulnerable to these effects. In contrast, steel is an excellent choice for use due to their structural characteristics, such as its high tensile strength, ductility, compressive good performance, high efficiency in weight — strength ratio, among other qualities. The cold formed thin-walled steel elements, are another type of very light profiles, although its use has been known for several decades, is in recent times that have extended their application, mainly in housing construction, and to a lesser scale commercial and industrial construction. The main advantage of this material is that it retains the mechanical properties of steel, but with a significant reduction in the weight of the items. The most common use of this type of profile is in the manufacture of structural frames as standard modules, the most common form it is assembly profile channel with rigid edge section and section profiles of single channel, with different dimensions and sizes. In full-scale testing and numerical simulation models, the system exhibits an excellent performance under differential displacements as those caused by subsidence, accepting considerable deformations without reaching the failure of structural elements. In the goodness of

Fermilab Research Program Workbook

International Nuclear Information System (INIS)

Rubinstein, R.

1984-05-01

The Fermilab Research Program Workbook has been published annually for the past several years to assist the Physics Advisory Committee in the yearly program review conducted during its summer meeting. While this is still a major aim, it is hoped that the Workbook will also prove useful to others seeking information on the current status of Fermilab experiments and the properties of beams at the Laboratory. In addition, short summaries of approved experiments are also included

Nuclear plant aging research program

International Nuclear Information System (INIS)

Eissenberg, D.M.

1987-01-01

The U.S. Nuclear Regulatory Commission, Office of Nuclear Regulatory Research, has established the Nuclear Plant Aging Research (NPAR) program in its Division of Engineering Technology. Principal contractors for this program include Oak Ridge National Laboratory, Brookhaven National Laboratory, Idaho National Engineering Laboratory, and Pacific Northwest Laboratory. The program goals are: to identify and characterize time-dependent degradation (aging) of nuclear plant safety-related electrical and mechanical components which could lead to loss of safety function; to identify and recommend methods for detecting and trending aging effects prior to loss of safety function so that timely maintenance can be implemented; and to recommend maintenance practices for mitigating the effects of aging. Research activities include prioritization of system and component aging in nuclear plants, characterization of aging degradation of specific components including identification of functional indicators useful for trending degradation, and testing of practical methods and devices for measuring the functional indicators. Aging assessments have been completed on electric motors, snubbers, motor-operated valves, and check valves. Testing of trending methods and devices for motor-operated valves and check valves is in progress

The relation between land use and subsidence in the Vietnamese Mekong delta

Science.gov (United States)

The Vietnamese Mekong delta is subsiding due to a combination of natural and human-induced causes. Over the past several decades, large-scale anthropogenic land-use changes have taken place as a result of increased agricultural production, population growth and urbanization in th...

Foraminiferal record of Holocene paleo-earthquakes on the subsiding south-western Poverty Bay coastline, New Zealand

International Nuclear Information System (INIS)

Hayward, B.W.; Sabaa, A.T.; Grenfell, H.R.; Cochran, U.A.; Clark, K.J.; Litchfield, N.J.; Wallace, L.M.; Marden, M.; Palmer, A.S.

2015-01-01

Foraminiferal faunas in 29 short cores (maximum depth 7 m) of estuarine and coastal wetland sediment were used to reconstruct the middle-late Holocene (last 7 ka) elevational history on the southern shores of Poverty Bay, North Island, New Zealand. This coast is on the southwest side of a rapidly subsiding area beneath western Poverty Bay. Modern Analogue Technique paleo-elevation estimates based on fossil foraminiferal faunas indicate that the four study areas have gradual late Holocene (<3.5 ka) subsidence rates that increase from the southwest (mean c. 0.5 m ka - - 1 ) to northeast (mean c. 1.0 m ka -1 ). Only two rapid, possibly co-seismic, vertical displacement events are recognised: (1) c. 1.2 m of subsidence at 5.7 ± 0.4 ka (cal yr BP), which may have been generated by a subduction interface earthquake centred offshore and recorded in other published studies in northern Hawkes Bay, c. 35 km to the south; and (2) c. 1 m of uplift (relative sea-level fall) at c. 4.5 ± 0.3 ka, which might have been generated by rupture on an offshore upper plate fault that also uplifted coastal terraces at Pakarae and Mahia, 40 km to the north and south of the study area, or by rupture on the subduction interface penetrating beneath Poverty Bay. No sudden displacement events are recognised during the last 4 ka although subsidence, possibly aseismic, has continued. (author).

Undergraduate Research Program Between SCU and SOFIA

Science.gov (United States)

Kulas, Kristin Rose; Andersson, B.-G.

2018-06-01

We present results on an undergraduate research program run in collaboration between Santa Clara University (SCU), a predominately undergraduate liberal arts college and the SOFIA Science Center/USRA. We have started a synergistic program between SCU and SOFIA (located at NASA Ames) where the students are able to be fully immersed in astronomical research; from helping to write telescope observing proposal; to observing at a world-class telescope; to reducing and analyzing the data that they acquired and ultimately to presenting/publishing their findings. A recently awarded NSF collaborative grant will allow us to execute and expand this program over the next several years. In this poster we present some of our students research and their success after the program. In addition, we discuss how a small university can actively collaborate with a large government-funded program like SOFIA, funded by NASA.

Risk factors for subsidence in anterior cervical fusion with stand-alone polyetheretherketone (PEEK) cages: a review of 82 cases and 182 levels.

Science.gov (United States)

Kao, Ting-Hsien; Wu, Chen-Hao; Chou, Yu-Ching; Chen, Hsien-Te; Chen, Wen-Hsien; Tsou, Hsi-Kai

2014-10-01

To determine risk factors for subsidence in patients treated with anterior cervical discectomy and fusion (ACDF) and stand-alone polyetheretherketone (PEEK) cages. Records of patients with degenerative spondylosis or traumatic disc herniation resulting in radiculopathy or myelopathy between C2 and C7 who underwent ACDF with stand-alone PEEK cages were retrospectively reviewed. Cages were filled with autogenous cancellous bone harvested from iliac crest or hydroxyapatite. Subsidence was defined as a decrease of 3 mm or more of anterior or posterior disc height from that measured on the postoperative radiograph. Eighty-two patients (32 males, 50 females; 182 treatment levels) were included in the analysis. Most patients had 1-2 treatment levels (62.2 %), and 37.8 % had 3-4 treatment levels. Treatment levels were from C2-7. Of the 82 patients, cage subsidence occurred in 31 patients, and at 39 treatment levels. Multivariable analysis showed that subsidence was more likely to occur in patients with more than two treatment levels, and more likely to occur at treatment levels C5-7 than at levels C2-5. Subsidence was not associated with postoperative alignment change but associated with more disc height change (relatively oversized cage). Subsidence is associated with a greater number of treatment levels, treatment at C5-7 and relatively oversized cage use.

Teacher Research Experience Programs = Increase in Student Achievement

Science.gov (United States)

Dubner, J.

2010-12-01

Columbia University's Summer Research Program for Science Teachers (SRP), founded in 1990, is one of the largest, best known university-based professional development programs for science teachers in the U.S. The program’s basic premise is simple: teachers cannot effectively teach science if they have not experienced it firsthand. For eight weeks in each of two consecutive summers, teachers participate as a member of a research team, led by a member of Columbia University’s research faculty. In addition to the laboratory experience, all teachers meet as a group one day each week during the summer for a series of pedagogical activities. A unique quality of the Summer Research Program is its focus on objective assessment of its impact on attitudes and instructional practices of participating teachers, on the performance of these teachers in their mentors’ laboratories, and most importantly, on the impact of their participation in the program on student interest and performance in science. SRP uses pass rate on the New York State Regents standardized science examinations as an objective measure of student achievement. SRP's data is the first scientific evidence of a connection between a research experience for teachers program and gains in student achievement. As a result of the research, findings were published in Science Magazine. The author will present an overview of Columbia's teacher research program and the results of the published program evaluation.

Generalization of the influence function method in mining subsidence

International Nuclear Information System (INIS)

Bello Garcia, A.; Mendendez Diaz, A.; Ordieres Mere, J.B.; Gonzalez Nicieza, C.

1996-01-01

A generic approach to subsidence prediction based on the influence function method is presented. The changes proposed to the classical approach are the result of a previous analysis stage where a generalization to the 3D problem was made. In addition other hypothesis in order to relax the structural principles of the classical model are suggested. The quantitative results of this process and a brief discussion of its method of employment is presented. 13 refs., 8 figs., 5 tabs

Building Innovation and Sustainability in Programs of Research.

Science.gov (United States)

Villarruel, Antonia M

2018-01-01

Innovation and sustainability are two important concepts of impactful programs of research. While at first glance these concepts and approaches may seem at odds, they are synergistic. We examine the social, political, and policy context as it relates to innovation and sustainability. We present an exemplar of a program of research and discuss factors to consider in developing innovative and sustainable programs of research. Innovation is an important component of sustainable programs of research. Understanding the social and political context and addressing relevant policy issues are factors to be considered in both innovation and sustainability. Innovation and sustainability, important components of research, are also central to clinical practice. Open communication between researchers and clinicians can support the acceleration of innovations and the integration of evidence-based findings in practice. © 2017 Sigma Theta Tau International.

Base Research Program

Energy Technology Data Exchange (ETDEWEB)

Everett Sondreal; John Hendrikson

2009-03-31

In June 2009, the Energy & Environmental Research Center (EERC) completed 11 years of research under the U.S. Department of Energy (DOE) Base Cooperative Agreement No. DE-FC26-98FT40320 funded through the Office of Fossil Energy (OFE) and administered at the National Energy Technology Laboratory (NETL). A wide range of diverse research activities were performed under annual program plans approved by NETL in seven major task areas: (1) resource characterization and waste management, (2) air quality assessment and control, (3) advanced power systems, (4) advanced fuel forms, (5) value-added coproducts, (6) advanced materials, and (7) strategic studies. This report summarizes results of the 67 research subtasks and an additional 50 strategic studies. Selected highlights in the executive summary illustrate the contribution of the research to the energy industry in areas not adequately addressed by the private sector alone. During the period of performance of the agreement, concerns have mounted over the impact of carbon emissions on climate change, and new programs have been initiated by DOE to ensure that fossil fuel resources along with renewable resources can continue to supply the nation's transportation fuel and electric power. The agreement has addressed DOE goals for reductions in CO{sub 2} emissions through efficiency, capture, and sequestration while expanding the supply and use of domestic energy resources for energy security. It has further contributed to goals for near-zero emissions from highly efficient coal-fired power plants; environmental control capabilities for SO{sub 2}, NO{sub x}, fine respirable particulate (PM{sub 2.5}), and mercury; alternative transportation fuels including liquid synfuels and hydrogen; and synergistic integration of fossil and renewable resources (e.g., wind-, biomass-, and coal-based electrical generation).

Programs of the Office of Energy Research

International Nuclear Information System (INIS)

1986-04-01

The programs of the Office of Energy Research, DOE, include several thousand individual projects and hundreds of laboratories, universities, and other research facilities throughout the United States. The major programs and activities are described briefly, and include high energy and nuclear physics, fusion energy, basic energy sciences, and health and environmental research, as well as advisory, assessment, support, and scientific computing activities

Natural and accelerated bioremediation research program plan

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-09-01

This draft plan describes a ten-year program to develop the scientific understanding needed to harness and develop natural and enhanced biogeochemical processes to bioremediate contaminated soils, sediments and groundwater at DOE facilities. The Office of Health and Environmental Research (OHER) developed this program plan, with advice and assistance from DOE`s Office of Environmental Management (EM). The program builds on OHER`s tradition of sponsoring fundamental research in the life and environmental sciences and was motivated by OHER`s and Office of Energy Research`s (OER`s) commitment to supporting DOE`s environmental management mission and the belief that bioremediation is an important part of the solution to DOE`s environmental problems.

Programs of the Office of Energy Research: Revision

International Nuclear Information System (INIS)

1987-06-01

In establishing each of the Federal Agencies that have been successively responsible for energy technologies and their development - the Atomic Energy Commission, the Energy Research and Development Administration, and, currently, the US Department of Energy (DOE) - Congress made specific provisions for the conduct of advanced and fundamental research. The purpose of this research has been to support the energy technology development programs by providing insight into fundamental science and associated phenomena and developing new or advanced concepts and techniques. Today, this responsibility rests with the Office of Energy Research (ER), DOE, whose present programs have their origins in pioneering energy-related research of this nature, which was initiated nearly 40 years ago. The Director, Office of Energy Research, also acts as the chief scientist and scientific advisor to the Secretary of Energy for the entire spectrum of energy research and development (R and D) programs of the Department. ER programs include several thousand individual projects and hundreds of laboratories, universities, and other research facilities throughout the Unites States. In the following pages, each of these programs and activities are described briefly for the information of the scientific community and the public at large. 5 figs., 6 tabs

HTGR safety research program

International Nuclear Information System (INIS)