共查询到20条相似文献,搜索用时 15 毫秒
1.
Yun Huang Bridget R. Scanlon Jean-Philippe Nicot Robert C. Reedy Alan R. Dutton Van A. Kelley Neil E. Deeds 《Hydrogeology Journal》2012,20(4):783-796
Understanding groundwater-pumpage sources is essential for assessing impacts on water resources and sustainability. The objective of this study was to quantify pumping impacts and sources in dipping, unconfined/confined aquifers in the Gulf Coast (USA) using the Texas Carrizo-Wilcox aquifer. Potentiometric-surface and streamflow data and groundwater modeling were used to evaluate sources and impacts of pumpage. Estimated groundwater storage is much greater in the confined aquifer (2,200?km3) than in the unconfined aquifer (170?km3); however, feasibility of abstraction depends on pumpage impacts on the flow system. Simulated pre-development recharge (0.96?km3/yr) discharged through evapotranspiration (ET, ~37%), baseflow to streams (~57%), and to the confined aquifer (~6%). Transient simulations (1980–1999) show that pumpage changed three out of ten streams from gaining to losing in the semiarid south and reversed regional vertical flow gradients in ~40% of the entire aquifer area. Simulations of predictive pumpage to 2050 indicate continued storage depletion (41% from storage, 32% from local discharge, and 25% from regional discharge capture). It takes ~100?yrs to recover 40% of storage after pumpage ceases in the south. This study underscores the importance of considering capture mechanism and long-term system response in developing water-management strategies. 相似文献
2.
The Middle East and North Africa (MENA) region is the world’s most water-stressed region, with its countries constituting 12 of the 15 most water-stressed countries globally. Because of data paucity, comprehensive regional-scale assessments of groundwater resources in the MENA region have been lacking. The presented study addresses this issue by using a distributed ArcGIS model, parametrized with gridded data sets, to estimate groundwater storage reserves in the region based on generated aquifer saturated thickness and effective porosity estimates. Furthermore, monthly gravimetric datasets (GRACE) and land surface parameters (GLDAS) were used to quantify changes in groundwater storage between 2003 and 2014. Total groundwater reserves in the region were estimated at 1.28 × 106 cubic kilometers (km3) with an uncertainty range between 816,000 and 1.93 × 106 km3. Most of the reserves are located within large sedimentary basins in North Africa and the Arabian Peninsula, with Algeria, Libya, Egypt, and Saudi Arabia accounting for approximately 75% of the region’s total freshwater reserves. Alternatively, small groundwater reserves were found in fractured Precambrian basement exposures. As for groundwater changes between 2003 and 2014, all MENA countries except for Morocco exhibited declines in groundwater storage. However, given the region’s large groundwater reserves, groundwater changes between 2003 and 2014 are minimal and represent no immediate short-term threat to the MENA region, with some exceptions. Notwithstanding this, the study recommends the development of sustainable and efficient groundwater management policies to optimally utilize the region’s groundwater resources, especially in the face of climate change, demographic expansion, and socio-economic development. 相似文献
3.
Estimating groundwater storage changes in the Mississippi River basin (USA) using GRACE 总被引:7,自引:0,他引:7
Matthew Rodell Jianli Chen Hiroko Kato James S. Famiglietti Joe Nigro Clark R. Wilson 《Hydrogeology Journal》2007,15(1):159-166
Based on satellite observations of Earth’s time variable gravity field from the Gravity Recovery and Climate Experiment (GRACE), it is possible to derive variations in terrestrial water storage, which includes groundwater, soil moisture, and snow. Given auxiliary information on the latter two, one can estimate groundwater storage variations. GRACE may be the only hope for groundwater depletion assessments in data-poor regions of the world. In this study, soil moisture and snow were simulated by the Global Land Data Assimilation System (GLDAS) and used to isolate groundwater storage anomalies from GRACE water storage data for the Mississippi River basin and its four major sub-basins. Results were evaluated using water level records from 58 wells set in the unconfined aquifers of the basin. Uncertainty in the technique was also assessed. The GRACE-GLDAS estimates compared favorably with the well based time series for the Mississippi River basin and the two sub-basins that are larger than 900,000 km2. The technique performed poorly for the two sub-basins that have areas of approximately 500,000 km2. Continuing enhancement of the GRACE processing methods is likely to improve the skill of the technique in the future, while also increasing the temporal resolution. 相似文献
4.
5.
黄河流域是中国重要的生态屏障和经济地带,上中下游面临着不同生态环境问题,水在生态环境问题的形成演化过程中起着重要作用。本文从黄河流域地下水动态特征、地下水资源的数量、质量及开发利用等方面,分析了黄河流域地下水资源及饮水安全状况。黄河流域年度地下水资源量393.55亿m~3,银川平原、河套平原等7处主要平原(盆地)地下水资源量为81.91亿m~3,占比超过20%;黄河流域地下水质量以Ⅰ~Ⅳ类为主,劣质地下水主要受总硬度、硫酸盐、铁、溶解性总固体等天然原生组分影响,砷、氟、硒、碘等原生组分超标是流域部分地区地下水饮水安全的主要威胁;2020年与2019年同期相比,黄河流域地下水位呈上游稳定、中游局部上升、下游下降的态势,主要地下水降落漏斗形态基本稳定。针对黄河源区、宁蒙河套平原等重点区段,分析了存在的主要生态环境问题,提出了全面开展流域水文地质与水资源调查评价,深入开展黄河流域及重点地区水平衡分析等工作建议。 相似文献
6.
Abdalla Eltom Mohamed Elsheikh Khalid A. Elsayed Zeinelabdein Shaza A. Elobeid 《Arabian Journal of Geosciences》2011,4(3-4):567-574
The River Gash Basin is filled by the Quaternary alluvial deposits, unconformably overlying the basement rocks. The alluvial deposits are composed mainly of unconsolidated layers of gravel, sand, silt, and clays. The aquifer is unconfined and is laterally bounded by the impermeable Neogene clays. The methods used in this study include the carry out of pumping tests and the analysis of well inventory data in addition to the river discharge rates and other meteorological data. The average annual discharge of the River Gash is estimated to be 1,056?×?106 m3 at El Gera gage station (upstream) and 587?×?106 m3 at Salam-Alikum gage station (downstream). The annual loss mounts up to 40% of the total discharge. The water loss is attributed to infiltration and evapotranspiration. The present study proofs that the hydraulic conductivity ranges from 36 to 105 m/day, whereas the transmissivity ranges from 328 to 1,677 m2/day. The monitoring of groundwater level measurements indicates that the water table rises during the rainy season by 9 m in the upstream and 6 m in the midstream areas. The storage capacity of the upper and middle parts of the River Gash Basin is calculated as 502?×?106 m3. The groundwater input reach 386.11?×?106 m3/year, while the groundwater output is calculated as 365.98?×?106 m3/year. The estimated difference between the input and output water quantities in the upper and middle parts of the River Gash Basin demonstrates a positive groundwater budget by about 20?×?106 m3/year 相似文献
7.
Yumi Iwasaki Kimihito Nakamura Haruhiko Horino Shigeto Kawashima 《Hydrogeology Journal》2014,22(8):1841-1855
Assessing factors that influence groundwater levels such as land use and pumping strategy, is essential to adequately manage groundwater resources. A transient numerical model for groundwater flow with infiltration was developed for the Tedori River alluvial fan (140 km2), Japan. The main water input into the groundwater body in this area is irrigation water, which is significantly influenced by land use, namely paddy and upland fields. The proposed model consists of two models, a one-dimensional (1-D) unsaturated-zone water flow model (HYDRUS-1D) for estimating groundwater recharge and a 3-D groundwater flow model (MODFLOW). Numerical simulation of groundwater flow from October 1975 to November 2009 was performed to validate the model. Simulation revealed seasonal groundwater level fluctuations, affected by paddy irrigation management. However, computational accuracy was limited by the spatiotemporal data resolution of the groundwater use. Both annual groundwater levels and recharge during the irrigation periods from 1975 to 2009 showed long-term decreasing trends. With the decline in rice-planted paddy field area, groundwater recharge cumulatively decreased to 61 % of the peak in 1977. A paddy-upland crop-rotation system could decrease groundwater recharge to 73–98 % relative to no crop rotation. 相似文献
8.
Hamza Jerbi Sylvain Massuel Christian Leduc Jamila Tarhouni 《Arabian Journal of Geosciences》2018,11(10):236
The aquifer of the semi-arid Kairouan plain has been exploited for decades to supply the growing irrigated agriculture and the need of drinking water. In parallel, the major hydraulic works drastically changed the natural groundwater recharge processes. The continuous groundwater level drop observed since the 1970s naturally raises the question of groundwater storage sustainability. To date, hydrogeological studies focused on groundwater fluxes, but the total amount of groundwater stored in the aquifer system has never been fully estimated. This is the purpose of the present paper. A complete database of all available geological, hydrogeological and geophysical data was created to build a 3D lithology model. Then, the lithological units were combined with the hydraulic properties to estimate the groundwater storage. Over the 700 km2 of the modelled area, the estimated storage in 2013 was around 18?×?109 m3 (equivalent to 80 times the annual consumption of 2010) with a highly variable spatial distribution. In 45 years (1968–2013), 12% of the amount of groundwater stored in the aquifer has been depleted. According to these results, individual farms will face strong regional disparities for their access to groundwater in the near future. 相似文献
9.
David Sanz Santiago Casta?o Eduardo Cassiraga Andr��s Sahuquillo Juan Jos�� G��mez-Alday Salvador Pe?a Alfonso Calera 《Hydrogeology Journal》2011,19(2):475-487
The Mancha Oriental System (MOS, 7,260?km2) is one of the largest aquifers within Spain, and is encompassed by the Jucar River Basin. Over the past 30?years, socioeconomic development within the region has been largely due to intensive use of groundwater resources for irrigating crops (1,000?km2). Groundwater pumping (406 million m3/year) has provoked a steady drop in the groundwater level and a reduction of MOS discharge to the Jucar River. The study aims to characterize the river?Caquifer relationship, to determine the influence that groundwater abstraction has on the river discharge. This research has advanced a three-dimensional large-scale numerical groundwater-flow model (MODFLOW 2000) in order to spatially and temporally evaluate, quantify and predict the river?Caquifer interactions that are influenced by groundwater abstraction in MOS. It is demonstrated that although groundwater abstraction increased considerably from the early 1980s to 2000, the depletion of water stored in the aquifer was lower than might be expected. This is mainly due to aquifer recharge from the Jucar River, induced by groundwater abstraction. The area of disconnection between the river and the water table (i.e. where groundwater head is lower than the riverbed) is found to have spread 20?km downstream from its position before pumping started. 相似文献
10.
Sahebrao Sonkamble 《Journal of the Geological Society of India》2014,83(5):535-548
Electrical resistivity methods are applied extensively for shallow sub-surface objectives but it has constraints in distinguishing the chemical characteristics of the medium. However, this complexity can be resolved by integrated investigations where geophysical anomaly would be validated with hydro-geochemical data. The present study highlights the notable importance of integrated geophysical and hydrogeological investigations in demarcating sub-surface pollution due to saline water intrusion and industrial effluents at Cuddalore coast in India. Geophysical scanning encompassing a total of 35 vertical electrical sounding (VES) were validated with drilling lithologs, water level and water quality parameters from a network of 125 observation wells at a test site of 17 km2. To understand the spatial variation of sub-surface contamination, two profiles of apparent resistivity sections were generated covering VES points parallel to the coast. Results revealed that, the low order of resistivity range 3 to 10 Ω-m (up to 30–40 m depth) and total dissolved solids range 2000 to 10,000 mg/l of groundwater reflects sub-surface contamination but cannot distinguish kind of salinity which is further verified by chemical analysis of Ca2+ (1200–2041 mg/l), SO4 2? (3000–9480 mg/l) which confirms the gypsum pollution and Na+ (750–1000 mg/l), Cl? (1000–2000 mg/l) designate the marine water contamination. Further, static groundwater head measurements demarcate the study area into above mean sea level (MSL) and below MSL zones. This study has provided a rapid and comprehensive picture about spatial variations of groundwater contamination which can help in planning, protection and safe management of coastal aquifers in India and worldwide. 相似文献
11.
Spatial change detection of glacial lakes in the Koshi River Basin,the Central Himalayas 总被引:2,自引:0,他引:2
Region warming and the resulting ongoing deglaciation have led to the formation of new glacial lakes and expansion of existing glacial lakes. For giving an overview of the distribution and expansion of glacial lakes in the Koshi River Basin (KRB) between the Central China and Nepal Himalayas in the recent 10 years, this paper aimed to analyze and assess recent spatial variability of glacial lake changes in the KRB, Central Himalayas using two inventory data of glacial lake in 2001 and 2010 in Nepal and Landsat TM/ETM+ data for the 1990s, 2000 and 2009 on the Chinese section of the KRB. The datasets show that there are 1,203 glacial lakes with a total area of 118.54 km2 in the KRB in 2009, in which 599 lakes are mapped in the Nepalese section of the KRB with a total of 25.92 km2, and 604 lakes in the Chinese section of the KRB with a total area of 92.62 km2. From 2000 to 2009, the total number of glacial lakes decreased from 1,668 to 1,203 with a reduction of 45.86 % in the KRB, whereas the total lake areas expanded by 10.60 % (i.e. 0.72 km2/a), from 111.35 to 118.54 km2 between 2000, 2001 and 2009, 2010. Especially, 17 lakes are identified as potentially dangerous glacial lakes (PDGLs) by International Centre for Integrated Mountain Development (ICIMOD) on the Nepalese section of the KRB in 2009. In the same period, 23 PDGLs are also identified on the Chinese section of the KRB and the total area increased by 77.46 % (i.e. 0.37 km2/a) from 1990 to 2010 and the expansion rate is significantly higher than 39 % (0.19 km2/a) of non-PDGLs. Therefore, there is a need for promoting the awareness of the hazard potential of glacier lakes to support proper planning of mitigation and adaptation strategies in this context. 相似文献
12.
Lina Mi Honglang Xiao Jianming Zhang Zhenliang Yin Yongping Shen 《Hydrogeology Journal》2016,24(4):971-986
Investigation of the evolution of the groundwater system and its mechanisms is critical to the sustainable management of water in river basins. Temporal and spatial distributions and characteristics of groundwater have undergone a tremendous change with the intensity of human activities in the middle reaches of the Heihe River Basin (HRB), the second largest arid inland river basin in northwestern China. Based on groundwater observation data, hydrogeological data, meteorological data and irrigation statistical data, combined with geostatistical analyses and groundwater storage estimation, the basin-scaled evolution of the groundwater levels and storage (from 1985 to 2013) were investigated. The results showed that the unbalanced allocation of water sources and expanded cropland by policy-based human activities resulted in the over-abstraction of groundwater, which induced a general decrease in the water table and groundwater storage. The groundwater level has generally fallen from 4.92 to 11.49 m from 1985 to 2013, especially in the upper and middle parts of the alluvial fan (zone I), and reached a maximum depth of 17.41 m. The total groundwater storage decreased by 177.52?×?108 m3; zone I accounted for about 94.7 % of the total decrease. The groundwater balance was disrupted and the groundwater system was in a severe negative balance; it was noted that the groundwater/surface-water interaction was also deeply affected. It is essential to develop a rational plan for integration and management of surface water and groundwater resources in the HRB. 相似文献
13.
J. J. Carrera-Hernández D. Carreón-Freyre M. Cerca-Martínez G. Levresse 《Hydrogeology Journal》2016,24(2):373-393
The city of Querétaro, located near the political boundary of the Mexican states of Querétaro and Guanajuato, relies on groundwater as it sole water supply. Groundwater extraction in the city increased from 21?×?106 m3/yr in 1970 to 104?×?106 m3/yr in 2010, with an associated drawdown of 100 m in some parts of the aquifer. A three-dimensional numerical groundwater-flow model has been developed that represents the historical evolution of the aquifer’s potentiometric levels and is used to simulate the effect of two scenarios: (1) a 40 % reduction in the extraction rate from public water supply wells in early 2011 (thus reducing the extraction to 62?×?106 m3/yr), and (2) a further reduction in 2021 to 1?×?106 m3/yr. The modeling results project a temporary recovery of the potentiometric levels after the 40 % reduction of early 2011, but a return to 2010 levels by 2020. If scenario 2 is implemented in 2021, the aquifer will take nearly 30 years to recover to the simulated levels of 1995. The model also shows that the wells located in the city of Querétaro started to extract water from part of the aquifer beneath the State of Guanajuato in the late 1970s, thus showing that the administrative boundaries used in Mexico to study and develop water resources are inappropriate, and consideration should be given to physical boundaries instead. A regional approach to studying aquifers is needed in order to adequately understand groundwater flow dynamics. 相似文献
14.
Yu Zhou Yanxin Wang Yilian Li François Zwahlen Julie Boillat 《Environmental Earth Sciences》2013,68(3):765-778
The central Jianghan Plain is the semi-closed basin in the middle reaches of Yangtze River. A total of 78 water samples targeting groundwater were collected from 75 sites in this study site, the area between Yangtze River and Han River, including rivers and lakes for temperature, pH, electrical conductivity (EC), total dissolved solids (TDS) and ion composition measurements. Correlation matrix was used to assess the geochemical and anthropogenic processes. The most confined groundwater was grouped into HCO3–Ca–Mg, while phreatic groundwater and surface water had a more diversified hydrochemistry. The spatial variation in overall water quality as well as comparison with WHO (World Health Organization) standards for drinking water is illustrated. Mn, As and NO3 ? concentrations were found to exceed the allowable limits for drinking water of WHO guidelines, and they also show remarkable spatial variations. Abnormally high nitrate concentration, up to 150–190 mg/l, was found only in phreatic groundwater, which suggested that the nitrate pollution might be caused by agricultural activities. The present study may be helpful in further studies concerning water quality issues in this area where groundwater is a vital source for drinking and other activities. 相似文献
15.
Venkatesh Uddameri Chandana Kakarlapudi E. Annette Hernandez 《Environmental Earth Sciences》2014,71(6):2573-2587
Groundwater, under sustainable management policies, can be an invaluable source of water to municipal, agricultural, and industrial sectors. Management, however, can be challenging given that historically, these resources have been privately owned and minimally regulated. This research details the development of a decision support system (DSS) which couples a GIS-based multi-criteria decision-making (MCDM) scheme with simulation-optimization routines to identify suitable regions for groundwater development and optimal preferences for apportioning those supplies to areas of demand in South Texas. The developed DSS consisted of three modules: (1) a GIS-based MCDM for identifying suitable locations for groundwater production; (2) a simulation-optimization model for estimating available groundwater; and (3) a transportation optimization model for redistributing the groundwater. Applying a comprehensive suite of nine exclusionary criteria in GIS resulted in only 15,304 km2 (5,909 mi2) suitable for groundwater production out of the original ~50,500 km2 (19,500 mi2). Two ideal sites were selected in the suitable region based on proposed major water supply projects in the study area. The projected groundwater extraction rates per month varied considerably over a year emphasizing a need for storage technologies. Furthermore, a transportation optimization model, which considered cost of storage and movement, was developed and applied to obtain the most optimal scheme to transport groundwater from potential supply centers located in Bee and Kennedy counties to projected water deficit areas of San Antonio, Laredo, and McAllen, TX, USA. Lastly, a full-factorial sensitivity analysis was carried out to check the impacts of the supply and demand factors on groundwater production and transport. Policies at the supply centers had a larger impact on the total availability of water, and policies at the demand centers had a larger impact on the total cost of the management scheme. Furthermore, an analysis of total volume stored in a storage and recovery system exhibited an inverse relationship with the groundwater development (supply side) policies and a direct relationship with the demand requirements. The developed DSS proved useful for determining the most optimal siting and distribution network for groundwater sources in South Texas. 相似文献
16.
Groundwater levels in hard-rock areas in India have shown very large declines in the recent past. The situation is becoming more critical due to a paucity of rainfall, limited surface water resources and an increasing pattern of groundwater extraction in these areas. Consequently, the Ground Water Department with the aid of World Bank has implemented the water structuring programme to mitigate groundwater scarcity and to develop a viable solution for sustainable development in the region. The present study has been undertaken to assess the impact of artificial groundwater recharge structures in the hard-rock area of Rajasthan, India. In this study groundwater level data (pre-monsoon and post-monsoon) of 85 dug-wells are used, spread over an area of 413.59 km2. The weathered and fractured gneissic basement rocks act as major aquifer in the area. Spatial maps for pre- and post-monsoon groundwater levels were prepared using the kriging interpolation technique with best fitted semi-variogram models (Spherical, Exponential and Gaussian). The groundwater recharge is calculated spatially using the water level fluctuation method. The entire study period (2004–2011) is divided into pre- (2004–2008) and post-intervention (2009–2011) periods. Based on the identical nature of total monsoon rainfall, two combinations of average (2007 and 2009) and more than average (2006 and 2010) rainfall years are selected from the pre- and post-intervention periods for further comparisons. All of the water harvesting structures are grouped into the following categories: as anicuts (masonry overflow structure); percolation tanks; subsurface barriers; and renovation of earthen ponds/nadis. A buffer of 100 m around the intervention site is taken for assessing the influence of these structures on groundwater recharge. The relationship between the monsoon rainfall and groundwater recharge is fitted by power and exponential functions for the periods of 2004–2008 and 2008–2011 with R 2 values of 0.95 and 0.98, respectively. The average groundwater recharge is found to be 18% of total monsoon rainfall prior to intervention and it became 28% during the post-intervention period. About 70.9% (293.43 km2) of the area during average rainfall and more than 95% (396.26 km2) of the area during above-average rainfalls show an increase in groundwater recharge after construction of water harvesting structures. The groundwater recharge pattern indicates a positive impact within the vicinity of intervention sites during both average and above-average rainfall. The anicuts are found to be the most effective recharge structures during periods of above-average rainfall, while subsurface barriers are responded well during average rainfall periods. In the hard-rock terrain, water harvesting structures produce significant increases in groundwater recharge. The geo-spatial techniques that are used are effective for evaluating the response of different artificial groundwater recharge techniques. 相似文献
17.
《China Geology》2021,4(3):455-462
The Luanhe River Delta is located in the center of the Circum-Bohai Sea Economic Zone. It enjoys rapid economic and social development while suffering relatively water scarcity. The overexploitation of groundwater in the Luanhe River Delta in recent years has caused the continuous drop of groundwater level and serious environmental and geological problems. This study systematically analyzes the evolution characteristics of the population, economy, and groundwater exploitation in the Luanhe River Delta and summarizes the change patterns of the groundwater flow regime in different aquifers in the Luanhe River Delta according to previous water resource assessment data as well as the latest groundwater survey results. Through comparison of major source/sink terms and groundwater resources, the study reveals the impacts of human activities on the groundwater resources and ecological environment in the study area over the past 30 years from 1990 to 2020. The results are as follows. The average annual drop rate of shallow groundwater and the deep groundwater in the centers of depression cones is 0.4 m and 1.64 m, respectively in the Luanhe River Delta in the past 30 years. The depression cones of shallow and deep groundwater in the study area cover an area of 545.32 km2 and 548.79 km2, respectively, accounting for more than 10% of the total area of the Luanhe River Delta. Overexploitation of groundwater has further aggravated land subsidence. As a result, two large-scale subsidence centers have formed, with a maximum subsidence rate of up to 120 mm/a. The drop of groundwater level has induced some ecological problems in the Luanhe River Delta area, such as the zero flow and water quality deterioration of rivers and continuous shrinkage of natural wetlands and water. Meanwhile, the proportion of natural wetland area to the total wetland area has been decreased from 99% to 8% and the water area from 1776 km2 to 263 km2. These results will provide data for groundwater overexploitation control, land subsidence prevention, and ecological restoration in plains and provide services for water resources management and national land space planning.© 2021 China Geology Editorial Office. 相似文献
18.
An assessment of the potential and impacts of winter water banking in the Sokh aquifer, Central Asia
The dynamics of artificial recharge of winter surface flows coupled with increased summer groundwater use for irrigation in the Sokh aquifer (Central Asia) have been investigated. Water release patterns from the giant Toktogul reservoir have changed, as priority is now given to hydropower generation in winter in Kyrgyzstan. Winter flows have increased and summer releases have declined, but the Syr Darya River cannot pass these larger winter flows and the excess is diverted to a natural depression, creating a 40?×?109m3 lake. A water balance study of all 18 aquifers feeding the Fergana Valley indicated the feasibility of winter groundwater recharge in storage created by summer abstraction. This modeling study examines the dynamics of the process in one aquifer over a 5-year period, with four scenarios: the current situation; increased groundwater abstraction of around 625 million (M) m3/year; groundwater abstraction with an artificial recharge of 144 Mm3/year, equivalent to the volume available in low flow years in the Sokh River; and with a larger artificial recharge of 268 Mm3/year, corresponding to high flow availability. Summer surface irrigation diversions can be reduced by up to 350 Mm3 and water table levels can be lowered. 相似文献
19.
The landslides in the Three Gorges Reservoir Region,China and the effects of water storage and rain on their stability 总被引:5,自引:0,他引:5
According to the statistics, there were about 1,736 landslides with the total volume of 1.339 × 1011 m3 in the 100 km2 area of upper reaches of the Yangtze River, in which about 94% of landslides are triggered by rain and water storage. Thus,
based investigation of the results of the landslides in this region, this paper completed a systematic study on the effects
of rainfall and water storage on the landslides in the region and found that the distribution of landslides over time and
space are well correlated with the precipitation distribution in this region; landslides are also strictly controlled by the
stratum, geological structure, river valley form, shore type, etc. Meanwhile, the pattern of water table variation of the
three gorges reservoir will do have very serious impacts on the stability of the slopes in this region. All research results
show that water storage and rainfall are the two important inducing factors that can cause a lot of large-scale landslides.
Therefore, some effective control measures for water storage and rainfall should be taken so as to minimize the impacts of
water on the stability of the slopes in the Three Gorges Reservoir Region of Yangtze River, China. 相似文献
20.
Abdalla E. M. Elsheikh Khalid A. Elsayed Zeielabdein Ibrahim A. A. Babikir 《Hydrogeology Journal》2009,17(8):2075-2082
The Khor Arbaat basin is the main source of potable water supply for the more than 750,000 inhabitants of Port Sudan, eastern Sudan. The variation in hydraulic conductivity and storage capacity is due to the heterogeneity of the sediments, which range from clay and silt to gravely sand and boulders. The water table rises during the summer and winter rainy seasons; it reaches its lowest level in the dry season. The storage capacity of the Khor Arbaat aquifer is estimated to be 21.75?×?106 m3. The annual recharge through the infiltration of flood water is about 1.93?×?106 m3. The groundwater recharge, calculated as underground inflow at the ‘upper gate’, is 1.33?×?105 m3/year. The total annual groundwater recharge is 2.06?×?106 m3. The annual discharge through underground outflow at the ‘lower gate’ (through which groundwater flows onto the coastal plain) is 3.29?×?105 m3/year. Groundwater discharge due to pumping from Khor Arbaat basin is 4.38?×?106 m3/year on average. The total annual groundwater discharge is about 4.7?×?106 m3. A deficit of 2.6?×?106 m3/year is calculated. Although the total annual discharge is twice the estimated annual recharge, additional groundwater flow from the fractured basement probably balances the annual groundwater budget since no decline is observed in the piezometric levels. 相似文献