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Book Environmental Research Center Papers

Download or read book Environmental Research Center Papers written by and published by . This book was released on 1982 with total page 70 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Geotitles

Download or read book Geotitles written by and published by . This book was released on 1993 with total page 524 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Climate Change Effects on Groundwater Resources

Download or read book Climate Change Effects on Groundwater Resources written by Holger Treidel and published by CRC Press. This book was released on 2011-12-02 with total page 422 pages. Available in PDF, EPUB and Kindle. Book excerpt: Climate change is expected to modify the hydrological cycle and affect freshwater resources. Groundwater is a critical source of fresh drinking water for almost half of the world’s population and it also supplies irrigated agriculture. Groundwater is also important in sustaining streams, lakes, wetlands, and associated ecosystems. But despite this, knowledge about the impact of climate change on groundwater quantity and quality is limited. Direct impacts of climate change on natural processes (groundwater recharge, discharge, storage, saltwater intrusion, biogeochemical reactions, chemical fate and transport) may be exacerbated by human activities (indirect impacts). Increased groundwater abstraction, for example, may be needed in areas with unsustainable or contaminated surface water resources caused by droughts and floods. Climate change effects on groundwater resources are, therefore, closely linked to other global change drivers, including population growth, urbanization and land-use change, coupled with other socio-economic and political trends. Groundwater response to global changes is a complex function that depends on climate change and variability, topography, aquifer characteristics, vegetation dynamics, and human activities. This volume contains case studies from diverse aquifer systems, scientific methods, and climatic settings that have been conducted globally under the framework of the UNESCO-IHP project Groundwater Resources Assessment under the Pressures of Humanity and Climate Change (GRAPHIC). This book presents a current and global synthesis of scientific findings and policy recommendations for scientists, water managers and policy makers towards adaptive management of groundwater sustainability under future climate change and variability.

Book Hydraulic Properties of the Aquifer Aquitard System and Their Impacts on Regional Groundwater Flow in the Pearl River Delta China

Download or read book Hydraulic Properties of the Aquifer Aquitard System and Their Impacts on Regional Groundwater Flow in the Pearl River Delta China written by Lichao Yang and published by . This book was released on 2017-01-26 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation, "Hydraulic Properties of the Aquifer-aquitard System and Their Impacts on Regional Groundwater Flow in the Pearl River Delta, China" by Lichao, Yang, 杨利超, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: Groundwater is now being considered as an alternative water supply in the Pearl River Delta (PRD) because of the increasing demand for fresh water coupled with deterioration in river water quality as a result of rapid urbanization and industrialization. There are thick aquitards in the PRD as a result of several times transgression and regression in the Holocene. This study considers this aquitards as a research object because it has a significant impact on the underneath confined aquifer. It is necessary to analyze the hydraulic properties of the aquitards. A slug-test is a reasonable method to determine the hydraulic conductivity and specific storage of the low-permeability aquitards of silt and clay in the PRD. In this study, several slug-test methods were used to determine the hydraulic parameters of aquitards in several piezometers at the key site MZ04in the PRD. The results from these methods were compared to obtain the most reasonable group of hydraulic parameters. A reasonable equivalent numerical method is applied at the key site MZ04 site after the calibration with the C-B-P solution and the KGS model. The natural groundwater regime is obtained, which is helpful for the further research. A three-dimensional numerical model using MODFLOW is carried out under some assumptions and the simplification for the sediments structure. The characteristics of regional groundwater flow and the influence of hydraulic properties of the aquifer-aquitard system on groundwater flow were analyzed. The simulated groundwater level both in the unconfined aquifer and confined aquifer agree reasonably well with the observed data. Study on the water budget of the groundwater showed that the quantity of ground water discharged from participation to participate the water exchange is very small. In the groundwater participated water exchange, 97% of them flow into rivers, while only 3% of them flow into the sea. Moreover, the vertical flow is more important than the horizontal flow to the regional ground water balance in aquitards according to the water budget obtained from the model. The research of the PRD needs numerous data due to the complicated deposition and evolution process of the sediments and the intensive river network. The modeling results are preliminary because of the complexity of the geological and hydrogeological conditions in the PRD and the limitation of the observed water level data. The hydraulic parameters calculated for this study and the model results can provide a basis for further research on groundwater in the PRD. DOI: 10.5353/th_b5153744 Subjects: Aquifers - China - Pearl River Delta Groundwater - China - Pearl River Delta

Book The Response of a Regional Unconfined Aquifer to Natural Recharge

Download or read book The Response of a Regional Unconfined Aquifer to Natural Recharge written by Wan Mokhtar Wan Nawang and published by . This book was released on 1983 with total page 79 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Aquifer Contamination and Protection

Download or read book Aquifer Contamination and Protection written by International Hydrological Programme and published by . This book was released on 1980 with total page 468 pages. Available in PDF, EPUB and Kindle. Book excerpt: Theoretical and practical aspects; case histories; appendix.

Book Response of Unconfined Aquifer Systems to Deep Percolation

Download or read book Response of Unconfined Aquifer Systems to Deep Percolation written by Miguel A. Mariño and published by . This book was released on 1975 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Investigations of the Response of an Unconfined Aquifer to Localized Recharge

Download or read book Investigations of the Response of an Unconfined Aquifer to Localized Recharge written by Peter S. Tinsley and published by . This book was released on 1968* with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Groundwater around the World

Download or read book Groundwater around the World written by Jean Margat and published by CRC Press. This book was released on 2013-03-19 with total page 376 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents a unique and up-to-date summary of what is known about groundwater on our planet, from a global perspective and in terms of area-specific factual information. Unlike most textbooks on groundwater, it does not deal with theoretical principles, but rather with the overall picture that emerges as a result of countless observations,

Book Guidebook to Studies of Land Subsidence Due to Ground water Withdrawal

Download or read book Guidebook to Studies of Land Subsidence Due to Ground water Withdrawal written by Joseph Fairfield Poland and published by . This book was released on 1984 with total page 346 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Response of Deep Aquifers to Climate Variability

Download or read book Response of Deep Aquifers to Climate Variability written by Karem Fathy Abdelgaber Abdelmohsen and published by . This book was released on 2020 with total page 91 pages. Available in PDF, EPUB and Kindle. Book excerpt: Our recent analysis of Temporal Gravity Recovery and Climate Experiment (GRACE) solutions over the largest aquifer system in Africa (the Nubian Sandstone Aquifer System: NSAS) revealed that while the response of deep aquifers to climatic variations remains a relatively slow process that takes thousands to tens of thousands of years, there is a much faster response in aquifers that are characterized by dense networks of faults, fractures and karst as is the case with the NSAS. This rapid groundwater flow, when it occurs, is detected as an increase in GRACETWS over areas downgradient and distant (hundreds of km) from the source areas over which increased precipitation occurred in wet periods. The increase in GRACETWS over these distant areas cannot be accounted for by an increase in precipitation, soil moisture, or surface water flow given the hyperarid conditions even during periods of increased precipitation over the source areas. In this research we will accomplish the following using the NSAS in North Africa as test sites: (1) investigate whether the rapid response observed over the NSAS could be common to many of the aquifers worldwide, (2) identify the conditions under which such rapid flow occurs, and (3) apply groundwater flow models in fractured rocks and use the models to develop sustainable and/or optimum scenarios for groundwater management in areas showing evidence of rapid groundwater flow. These three tasks will be accomplished by conducting the following for each of the investigated aquifer systems: (1) use satellite-based precipitation mission data to identify temporal (short-term climate variability: wet and dry periods) and spatial variations of precipitation over areas of interest (source versus discharge areas), (2) identify the spatial and temporal response of GRACETWS to short climate variability over the areas of interest, (3) generate GRACETWS phase, difference, and amplitude images to investigate the direction and extent of GRACETWS variations that are indicative of mass movement in dry and wet periods and seasons; (4) delineate potential preferred pathways for groundwater flow by mapping fault traces from shaded relief maps, radar backscatter images, and geologic maps and their postulated extension in the subsurface from tilt derivative (TDR) product of a selected Gravity Field and Steady-State Ocean Circulation Explorer (GOCE)-based global geopotential model (GGM). Finally GRACE-based inferences will be validated using: (1) field data (temporal head data, isotopic and geochemical composition for groundwater samples) along the identified structures and satellite-based (SMOS) soil moisture content to test whether the identified structures represent preferred pathways for groundwater flow, and (2) conceptual flow models that simulate the rapid groundwater flow from the source areas towards discharge areas along preferred pathways and a much slower flow in the surrounding media. Findings will provide new insights into the response of large, deep aquifers to climate variability and address the sustainability of the NSAS and similar fossil aquifers worldwide.

Book Subsidence due to Fluid Withdrawal

Download or read book Subsidence due to Fluid Withdrawal written by E.C. Donaldson and published by Elsevier. This book was released on 1995-03-29 with total page 519 pages. Available in PDF, EPUB and Kindle. Book excerpt: Subsidence of geologic surface structures due to withdrawal of fluids from aquifers and petroleum reservoirs is a phenomenon experienced throughout the world as the demand for water and hydrocarbons increases with increasing population growth. This book addresses the definition and theories of subsidence, and the influences of unique conditions on subsidence; it includes discussions of specific field cases and a basic mathematical model of reservoir compaction and accompanying loss of porosity and permeability. The book is designed as a reference for readers giving immediate access to the geological events that establish conditions for compaction, the mathematical theories of compaction and subsidence, and practical considerations of field case histories in various regions of the world.

Book Groundwater Availability of the Central Valley Aquifer California

Download or read book Groundwater Availability of the Central Valley Aquifer California written by Claudia C. Faunt and published by Geological Survey. This book was released on 2009 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: