Evaluation of long-term groundwater level data in regular monitoring wells,Barka, Sultanate of Oman     

Natarajan Rajmohan  Ahmed Al-Futaisi  Ahmad Jamrah 《水文研究》2007,21(24):3367-3379

A detailed investigation was carried out to evaluate long-term groundwater level fluctuation in regular monitoring wells constructed by the Ministry of Water Resources in Barka, Sultanate of Oman. For this study, groundwater level data for 71 wells and rainfall data from six stations were collected from 1984 to 2003 and analysed. Based on long-term water level fluctuation, groundwater wells are classified into three groups. In group 1, water level shows a long-term cyclic trend without yearly fluctuation whereas in group 2 the water level declined continuously until 1995 followed by a constant water level. In group 3, water level decreases continuously throughout the study periods with rapid annual cyclic variation. Group 1 wells show high water-level fluctuations (5 to 10 m) and seem to be regulated by discharge (lateral flow) from this aquifer and recharge from the adjacent Jabal Akhdar mountainous region. Constant trend in water level after 1995 in group 2 wells illustrates the advancement of saline–fresh water interface to the inland due to heavy pumping which is justified by higher electrical conductivity and Cl/HCO₃ ratio. In group 3 wells, the water level dropped continuously due to overabstraction by agricultural farms and human settlements. In addition, wells existing near the recharge dams express the influences of recharge dams and rainfall, and exhibit high water-level fluctuations during heavy rainfall periods. The long-term regional variation indicates that water level drops continuously in the coastal and central parts of the study region. Linear regression analysis revealed that the decline in water level is 0·3–0·4 m year⁻¹ near the coastal and central parts of the study area and is almost constant in the remaining area. We conclude that the contribution of man-made activities on groundwater level is well compared with natural factors. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

Groundwater modelling to quantify the effect of water harvesting structures in Wagarwadi watershed,Parbhani district,Maharashtra, India     

K. P. Gore  M. S. Pendke  V. V. S. Gurunadha Rao  C. P. Gupta 《水文研究》1998,12(7):1043-1052

Marathwada Agricultural University, Pharbani, has developed about 560 hectares of Wagarwadi watershed in Pharbani district since 1987. Groundwater monitoring on 16 observations wells at weekly intervals commenced in January 1992, and rainfall and pan evaporation has been measured daily at a hydrometeorological station situated in the nearby university campus. Aquifer parameters, namely, transmissivity and specific yield, have been estimated by carrying out a pumping test on a large diameter well. Groundwater recharge resulting from rainfall has been estimated using a water balance model of the soil moisture zone considering soil zone thickness and crops grown. The SCS (Soil Conservation Service) curve number method was used for surface runoff estimation. The groundwater flow model has been constructed using the nested squares, finite difference method. Nested square meshes of sizes 160 m×160 m and 80 m×80 m have been used and the steady-state condition of aquifer system was simulated in the model assuming the June 1992 water level configuration under equilibrium conditions. The model has been calibrated for transient conditions incorporating additional seepage from the water harvesting structures and their contribution to the groundwater regime has been assessed. © 1998 John Wiley & Sons, Ltd.  相似文献   

Impacts of Seasonal Pumping on Stream‐Aquifer Interactions in Miryang,Korea          下载免费PDF全文

Hyeonju Lee  Min‐Ho Koo  Yongcheol Kim 《Ground water》2017,55(6):906-916

Large agricultural fields in South Korea are located mostly on alluvial plains, where a significant amount of groundwater is used for heating of water‐curtain insulated greenhouses. Such greenhouses are commonly used for crop cultivation during the winter dry season from November to March. After use the groundwater is discharged directly into streams, causing groundwater depletion. A hydrogeological study was carried out in a typical agricultural area of this type, located on an alluvial aquifer near the Nakdong River. Groundwater levels, chemical characteristics, and temperatures from 68 observation wells were analyzed to determine the impacts of seasonal groundwater pumping on the groundwater system and stream‐aquifer interactions. Our results show that the groundwater system has not yet reached a state of dynamic equilibrium. Decades of excessive seasonal pumping have caused a gradual decline of groundwater levels, leading to groundwater depletion, especially in areas further from the river. Seasonal pumping has also significantly affected groundwater quality in the aquifer near the river. Groundwater temperature is decreasing (in this case a disadvantage), and saline groundwater is being diluted by induced recharge. The results of this study provide a basic outline for effective integrated water management that is widely applicable in South Korea.  相似文献   

Evidence for extreme variations in the permeability of laterite from a detailed analysis of well behaviour in Nigeria          下载免费PDF全文

H. C. Bonsor  A. M. MacDonald  J. Davies 《水文研究》2014,28(10):3563-3573

Laterite soils are widespread in tropical Africa and have a large impact on the hydrology of the areas they cover. The permeability of laterite helps determine the partitioning of runoff and interflow and regulates groundwater recharge to underlying bedrock. Groundwater within laterite also forms a widespread source of drinking water, typically from unimproved hang‐dug‐wells. Despite its importance, there is little published information on laterite aquifer properties. In this study, data from a 6 m deep well in Nigeria have been analysed to characterise the hydraulic conductivity of the laterite from repeated pumping tests. Transmissivity measurements from 40 tests spread out across a hydrological year varied from 0.1 to 1000 m²/d. Further interpretation of the data demonstrate a strong non‐linear decrease in horizontal hydraulic conductivity with depth, characterised by an upper horizon of extreme permeability (400 m/d), and a much lower permeability profile beneath (<0.1 m/d). These data are substantiated with observations from other wells throughout the area. This non‐linear permeability structure has several implications: the upper laterite can facilitate rapid lateral throughflow in the wet season, enabling contaminants to be transported significant distances (up to 1 km); natural groundwater levels are restricted to a narrow range for much of the year; and, in the dry season, the lower permeability of the deeper laterite restricts the amount of water which can be abstracted from shallow wells, leading to well failure. The work highlights the need for a wider study to better understand laterite soils and the role they play in regional hydrology. © 2013 Natural Environment Research Council. Hydrological Processes published by John Wiley & Sons Ltd.  相似文献   

Understanding the dynamics and contamination of an urban aquifer system using groundwater age (14C, 3H,CFCs) and chemistry          下载免费PDF全文

Jürgen Mahlknecht  Arturo Hernández‐Antonio  Christopher J. Eastoe  Carol Tamez‐Meléndez  Rogelio Ledesma‐Ruiz  José A. Ramos‐Leal  Nancy Ornelas‐Soto 《水文研究》2017,31(13):2365-2380

The quality of the groundwater supplying drinking water to the Guadalajara metropolitan area has deteriorated due to both endogenic and exogenic processes. Previous studies of this complex neotectonic volcanic environment suggest that the sources of contamination here are underground fluids derived from an active volcanic center and surface wastewater derived from regional land‐use intensification. This study uses isotopic, gaseous, and chemical signatures to more comprehensively characterize this groundwater flow and its contamination paths. Groundwater is mainly recharged at the La Primavera Caldera to the west and is discharged into the Santiago River to the east. The exception to this trend is the Toluquilla area, where groundwater most likely represents rainfall originating from outside the basin limits. Evaporation affects groundwater in these areas, especially waters that have been affected by recycling below urban areas in the Atejamac area and by intensive agricultural activity in the Toluquilla area. Additionally, we present evidence that groundwater flow through alluvial sediments and tuffs in deeper wells mixes with a lower aquifer unit in basaltic‐andesitic rocks, which are in contact with hydrothermal fluids. Groundwater ages range from postbomb in the western and northwestern regions of the study area (i.e., the Atemajac aquifer unit) to Late Pleistocene in the southern and southeastern regions (i.e., the Toluquilla aquifer unit). Recently recharged water records little mixing and is located mostly in or near the La Primavera volcanic system. As groundwater undergoes gravitational flow towards discharge areas, it mixes with older water components. Chloride and sodium concentrations above natural background levels are primarily related to volcanic activity, nitrate is associated with human activities, and sulfate originates from both anthropogenic sources and water–rock interactions. Nitrate originating from land‐use activities (such as sewers, septic tanks, landfills, and agricultural fields) that is introduced into the deeper part of the groundwater system is expected to travel with the groundwater to the discharge areas because oxidizing conditions will prevent microbial reduction. See Supplementary Information.  相似文献   

Groundwater responses to the 2011 Tohoku Earthquake on Jeju Island,Korea     

Soo‐Hyoung Lee  Kyoochul Ha  Se‐Yeong Hamm  Kyung‐Seok Ko 《水文研究》2013,27(8):1147-1157

Groundwater responses at 15 monitoring wells on Jeju Island were observed in relation to the magnitude 9.0 Tohoku Earthquake off the Pacific coast of Honshu, Japan, on 11 March 2011, at 14:46:23 h local time (05:46:24 h UTC time). In coastal areas, the groundwater level responses to the earthquake were oscillatory at 12 wells, and the range of the maximum groundwater level changes was 3–192.4 cm. The response durations were approximately 1–62 min. The relationship between the maximum groundwater level changes and the response durations displayed a high correlation coefficient (r = 0.81). Groundwater temperature changes were also observed at 7 of 12 wells 3–10 min after the seismic wave arrived, and the range was from 0.01 °C to 1.20 °C. In mid‐elevation areas, the groundwater level changes appeared in three different forms: oscillatory, spiky and persistent. The groundwater temperature changes were also observed at two wells. One indicated decreasing and recovering temperatures, and the other exhibited rising and persistent temperatures. The primary temperature changes occurred 5–6 min after the earthquake and 2–3 min after the seismic wave arrived. In addition, the electrical conductivities at the depth of the transition zone were monitored, and the responses to the earthquake appeared at all three wells. Although the electrical conductivity and temperature changes were not well understood, groundwater inflow and mixing were likely caused by the earthquake, and the responses were various and site specific. The responses to the earthquake were closely related to the hydrogeological characteristics at each monitoring well, and a more detailed hydrogeological characterization is needed to understand the mechanisms related to earthquakes in general. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

Methods of groundwater recharge estimation in eastern Mediterranean—a water balance model application in Greece,Cyprus and Jordan     

E. Zagana  Ch. Kuells  P. Udluft  C. Constantinou 《水文研究》2007,21(18):2405-2414

Groundwater recharge studies in semi‐arid areas are fundamental because groundwater is often the only water resource of importance. This paper describes the water balance method of groundwater recharge estimation in three different hydro‐climatic environments in eastern Mediterranean, in northwest Greece (Aliakmonas basin/Koromilia basin), in Cyprus (Kouris basin and Larnaka area) and in Jordan (northern part of Jordan). For the Aliakmonas basin, groundwater recharge was calculated for different sub‐catchments. For the Upper Aliakmonas basin (Koromilia basin), a watershed‐distributed model was developed and recharge maps were generated on a daily basis. The mean annual recharge varied between 50 and 75 mm/year (mean annual rainfall 800 mm/year). In Cyprus, the mean groundwater recharge estimates yielded 70 mm/year in the Kouris basin. In the Larnaka area, groundwater recharge ranged from 30 mm/year (lowland) to 200 mm/year (mountains). In Jordan, the results indicated recharge rates ranging from 80 mm/year for very permeable karstified surfaces in the upper part of the Salt basin, where rainfall reaches 500 mm/year to less than 10 mm/year and to only about 1 mm/year in the southernmost part of the basin. For the north part of Jordan, a watershed‐distributed model was developed and recharge maps were generated. This water balance model was used for groundwater recharge estimations in many regions with different climatic conditions and has provided reliable results. It has turned out to be an important tool for the management of the limited natural water resources, which require a detailed understanding of regional hydro(geo)logical processes. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

Spatio‐temporal analysis of groundwater recharge and mound dynamics in an unconfined aquifer: a GIS‐based approach     

Ritesh Vijay  Nikhil Panchbhai  Apurba Gupta 《水文研究》2007,21(20):2760-2764

Groundwater recharge and mounding of water‐table is a complex phenomenon involving time‐ and space‐dependent hydrologic processes. The effect of long‐term groundwater mounding in the aquifer depends on soil, aquifer geometry and the area contributing to recharge. In this paper, a GIS‐based spatio‐temporal algorithm has been developed for the groundwater mound dynamics to estimate the potential rise in the water‐table and groundwater volume balance residual in an unconfined aquifer. The recharge and mound dynamics as predicted using the methodology recommended here were compared with those using the Hantush equation, and the differences were quite significant. The significance of the study is to assess the effectiveness of the basin in terms of its hydrologic and hydraulic properties for sustainable management of groundwater recharge. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

Reliability of recharge rates estimated from groundwater age with a simplified analytical approach     

Yanhui Dong  Yueqing Xie  Jun Zhang  Andrew J. Love  Xin Dai 《水文研究》2021,35(5):e14160

Groundwater age is often used to estimate groundwater recharge through a simplified analytical approach. This estimated recharge is thought to be representative of the mean recharge between the point of entry and the sampling point. However, given the complexity in actual recharge, whether the mean recharge is reasonable is still unclear. This study examined the validity of the method to estimate long-term average groundwater recharge and the possibility of obtaining reasonable spatial recharge pattern. We first validated our model in producing reasonable age distributions using a constant flux boundary condition. We then generated different flow fields and age patterns by using various spatially varying flux boundary conditions with different magnitudes and wavelengths. Groundwater recharge was estimated and analysed afterwards using the method at the spatial scale. We illustrated the main findings with a field example in the end. Our results suggest that we can estimate long-term average groundwater recharge with 10% error in many parts of an aquifer. The size of these areas decreases with the increase in both the amplitude and the wavelength. The chance of obtaining a reasonable groundwater recharge is higher if an age sample is collected from the middle of an aquifer and at downstream areas. Our study also indicates that the method can also be used to estimate local groundwater recharge if age samples are collected close to the water table. However, care must be taken to determine groundwater age regardless of conditions.  相似文献   

Hybrid-optimization algorithm for the management of a conjunctive-use project and well field design     

Chiu YC  Nishikawa T  Martin P 《Ground water》2012,50(1):103-117

Hi-Desert Water District (HDWD), the primary water-management agency in the Warren Groundwater Basin, California, plans to construct a waste water treatment plant to reduce future septic-tank effluent from reaching the groundwater system. The treated waste water will be reclaimed by recharging the groundwater basin via recharge ponds as part of a larger conjunctive-use strategy. HDWD wishes to identify the least-cost conjunctive-use strategies for managing imported surface water, reclaimed water, and local groundwater. As formulated, the mixed-integer nonlinear programming (MINLP) groundwater-management problem seeks to minimize water-delivery costs subject to constraints including potential locations of the new pumping wells, California State regulations, groundwater-level constraints, water-supply demand, available imported water, and pump/recharge capacities. In this study, a hybrid-optimization algorithm, which couples a genetic algorithm and successive-linear programming, is developed to solve the MINLP problem. The algorithm was tested by comparing results to the enumerative solution for a simplified version of the HDWD groundwater-management problem. The results indicate that the hybrid-optimization algorithm can identify the global optimum. The hybrid-optimization algorithm is then applied to solve a complex groundwater-management problem. Sensitivity analyses were also performed to assess the impact of varying the new recharge pond orientation, varying the mixing ratio of reclaimed water and pumped water, and varying the amount of imported water available. The developed conjunctive management model can provide HDWD water managers with information that will improve their ability to manage their surface water, reclaimed water, and groundwater resources.  相似文献   

A two‐dimensional analytical solution for groundwater flow in a leaky confined aquifer system near open tidal water     

Zhonghua Tang  Jiu J. Jiao 《水文研究》2001,15(4):573-585

Groundwater in coastal areas is commonly disturbed by tidal fluctuations. A two‐dimensional analytical solution is derived to describe the groundwater fluctuation in a leaky confined aquifer system near open tidal water under the assumption that the groundwater head in the confined aquifer fluctuates in response to sea tide whereas that of the overlying unconfined aquifer remains constant. The analytical solution presented here is an extension of the solution by Sun for two‐dimensional groundwater flow in a confined aquifer and the solution by Jiao and Tang for one‐dimensional groundwater flow in a leaky confined aquifer. The analytical solution is compared with a two‐dimensional finite difference solution. On the basis of the analytical solution, the groundwater head distribution in a leaky confined aquifer in response to tidal boundaries is examined and the influence of leakage on groundwater fluctuation is discussed. Copyright © 2001 John Wiley & Sons, Ltd.  相似文献   

Impacts on groundwater recharge areas of megacity pumping: analysis of potential contamination of Kolkata,India, water supply     

Paulami Sahu  Holly A. Michael  Clifford I. Voss  Pradip K. Sikdar 《水文科学杂志》2013,58(6):1340-1360

Abstract

Water supply to the world’s megacities is a problem of quantity and quality that will be a priority in the coming decades. Heavy pumping of groundwater beneath these urban centres, particularly in regions with low natural topographic gradients, such as deltas and floodplains, can fundamentally alter the hydrological system. These changes affect recharge area locations, which may shift closer to the city centre than before development, thereby increasing the potential for contamination. Hydrogeological simulation analysis allows evaluation of the impact on past, present and future pumping for the region of Kolkata, India, on recharge area locations in an aquifer that supplies water to over 13 million people. Relocated recharge areas are compared with known surface contamination sources, with a focus on sustainable management of this urban groundwater resource. The study highlights the impacts of pumping on water sources for long-term development of stressed city aquifers and for future water supply in deltaic and floodplain regions of the world.

Editor D. Koutsoyiannis

Citation Sahu, P., Michael, H.A., Voss, C.I., and Sikdar, P.K., 2013. Impacts on groundwater recharge areas of megacity pumping: analysis of potential contamination of Kolkata, India, water supply. Hydrological Sciences Journal, 58 (6), 1340–1360.  相似文献   

Groundwater recharge and discharge in a hyperarid alluvial plain (Akesu,Taklimakan Desert,China)     

Qiuhong Tang  Heping Hu  Taikan Oki 《水文研究》2007,21(10):1345-1353

Groundwater recharge and discharge in the Akesu alluvial plain were estimated using a water balance method. The Akesu alluvial plain (4842 km²) is an oasis located in the hyperarid Tarim River basin of central Asia. The land along the Akesu River has a long history of agricultural development and the irrigation area is highly dependent on water withdrawals from the river. We present a water balance methodology to describe (a) surface water and groundwater interaction and (b) groundwater interaction between irrigated and non‐irrigated areas. Groundwater is recharged from the irrigation system and discharged in the non‐irrigated area. Uncultivated vegetation and wetlands are supplied from groundwater in the hyperarid environment. Results show that about 90% of groundwater recharge came from canal loss and field infiltration. The groundwater flow from irrigated to non‐irrigated areas was about 70% of non‐irrigated area recharge and acted as subsurface drainage for the irrigation area. This desalinated the irrigation area and supplied water to the non‐irrigated area. Salt moved to the non‐irrigation area following subsurface drainage. We conclude that the flooding of the Akesu River is a supplemental groundwater replenishment mechanism: the river desalinates the alluvial plain by recharging fresh water in summer and draining saline regeneration water in winter. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

Temporary fluoride concentration changes in groundwater in the context of impact assessment in the Vaniyar sub-basin,South India     

《Acta Geochimica》2017,(1)

India's surface water and groundwater distribution is temporally variable due to the monsoon.Agriculture is one of the dominant economic sectors in India.Groundwater quality is regularly assessed to determine usability for drinking and irrigation.In this study,World Health Organization and Bureau of Indian Standards guidelines were used to determine suitability of groundwater near artificial recharge structures(ARS) with a focus on the structures impact on groundwater quality.Groundwater resources were evaluated for irrigation suitability using electrical conductivity(EC),sodium adsorption ratio,the US Salinity Laboratory diagram,sodium concentration,Wilcox's diagram,Kelly's index,and Doneen's permeability index.EC and major ions were tested in recharge areas at different distances from the ARS.The construction of ARS at optimal distances along major streams has improved groundwater quantity and quality in the subbasin.Before construction of ARS,fluoride concentrations were higher;after construction,fluoride was reduced in most locations.Water stored in the check dam and groundwater in the wells closer to the structure were suitable for both drinking and irrigation purposes.Impact of ARS on nearby groundwater quality was observed at Pallipatti,Mulayanur,Venkadasamuthram,Pudupatti,Poyyappatti,Harurl,and Sekkampatti.More distant sites included Pappiredipatti,Nambiyappati,Menasi,Harur,Todampatti,and Adikarapatti.Data demonstrated improved groundwater quality in the area of the ARS.Through recharge,the non-potable fluoride in the region is reduced to the permissible limit for human consumption.  相似文献   

Numerical groundwater modelling as an effective tool for management of water resources in arid areas     

Mohamed El Alfy 《水文科学杂志》2013,58(6):1259-1274

Abstract

Groundwater, possibly of fossil origin, is used for water supply in some arid regions where the replenishment of groundwater by precipitation is low. Numerical modelling is a helpful tool in the assessment of groundwater resources and analysis of future exploitation scenarios. To quantify the groundwater resources of the East Owienat area in the southwest of the Western Desert, Egypt, the present study assesses the groundwater resources management of the Nubian aquifer. Groundwater withdrawals have increased in this area, resulting in a disturbance of the aquifer’s natural equilibrium, and the large-scale and ongoing depletion of this critical water reserve. Negative impacts, such as a decline in water levels and increase in salinity, have been experienced. The methodology includes application of numerical groundwater modelling in steady and transient states under different measured and abstraction scenarios. The numerical simulation model developed was applied to assess the responses of the Nubian aquifer water level under different pumping scenarios during the next 30 years. Groundwater management scenarios are evaluated to find an optimal management solution to satisfy future needs. Based on analysis of three different development schemes that were formulated to predict the future response of the aquifer under long-term water stress, a gradual increase in groundwater pumping to 150% of present levels should be adopted for protection and better management of the aquifer. Similar techniques could be used to improve groundwater management in other parts of the country, as well as other similar arid regions.