Water Resource Development Study for a Mining Region

A water resource development study has been carried out for a proposed lignite mining area at Bhavnagar district of Gujarat state in India. This work is essentially a case study that uses standard methodology already applied in earlier research studies. The study covers assessment of water resources for the present and future, water balance status and formulation of a management and conservation strategy for the area. Ramdasiya watershed is considered as influencing zone having 31.92 km² area and covering full or part of ten villages with 13 647 population. There is no perennial river or major surface water bodies in the study area and annual average rainfall is only 567 mm. The groundwater is generally potable. Annual utilisable groundwater resource available in the area is 3.30 hm³ and present annual ground water demand for area is 2.967 hm³, whereas annual demand for various uses in theyear 2010 and 2020 would be around 3.298 and 3.659 hm³, respectively. The above problem of water scarcity in theregion has to be mitigated by immediate initiation of suitable short- and long-term water supply augmentation strategy for enhancing the groundwater recharge. To reduce the heavy surface runoff loss (around 40% of rainfall, although some part of it is also utilized as consumptive used) and enhance the groundwater recharge capacity of the area, suitable water retaining structures should be constructed. Interbasin transfer of water is also required to artificially recharge the aquifers for the augmentation of the groundwater potential of the area so as to meet the future demands.     

Delineation of Groundwater Potential Zones of Coastal Groundwater Basin Using Multi-Criteria Decision Making Technique

Delineation of groundwater potential zones (GWPZ) has been performed for a coastal groundwater basin of eastern India. The groundwater potential zone index (GWPZI) map is generated by using Analytic Hierarchy Process (AHP) from different influencing features, e.g., Land Use/Land Cover (LU/LC), soil (S), geomorphology (GM), hydrogeology (HG), surface geology (SG), recharge rate (RR), drainage density (DD), rainfall (RF), slope (Sl), surface water bodies (SW), lineament density (LD), and Normalized Difference Vegetative Index (NDVI). Recharge rate values are estimated from hydrological water balance model. Overlay weighted sum method is used to integrate all thematic feature maps to generate GWPZ map of the study area. Four zones have been identified for the coastal groundwater basin [very good: 36.39 % (273.53 km², good: 43.57 % (327.47 km²), moderate: 18.27 % (137.30 km²), and poor: 1.77 % (13.27 km²)]. Areas in north to south-west and south-east direction show very good GWPZ due to the presence of low drainage density. GWPZ map and well yield values show good agreement. Sensitivity analysis reveals that exclusion/absence of rainfall and lineament density increases the poor groundwater potential zones. Omission of hydrogeology, soils, surface geology, and NDVI show maximum increase in good GWPZ. Obtained GWPZ map can be utilized effectively for planning of sustainable agriculture. This analysis demonstrates the potential applicability of the methodology for a general coastal groundwater basin.     

Modeling Anthropogenic Impacts and Hydrological Processes on a Wetland in China

In many rapidly urbanizing countries like China, wetlands are constantly affected by anthropogenic factors such as landscaping, additional abstractions, reduction in catchment perviousness, etc. Thus, modeling of such anthropogenic factors should be explicitly considered when simulating wetlands. In this paper, the wetland module in a distributed hydrological model, SWAT, is modified to simulate the artificial water input to the designated wetlands. Local river runoff is used as the water sources to study the wetland restoration potential and to analyze the effects on local hydrological cycle and sea outflow. The QingDianWa depression, near Tianjin city, China, is used as a case study to study the restoration impact. Results showed that after restoration, the QinDianWa depression can reduce the potential impact of flooding by an average of 61 million m³ per year, increase the annual surface runoff by about 32 million m³ in non-flood seasons, and increase groundwater recharge by 9.4 million m³. This illustrated the importance of wetland restoration on flood control, river flow increase, groundwater recharge, and flood reclamation. But with local water resources is far from meeting the demands of wetland restoration, the actual restored water surface area is only 21.5 and 40.9 km² for the designated surface areas of 60 and 150 km² respectively. Compared with nature wetlands without human disturbance, the anthropogenic effect of reduction of runoff and groundwater recharge may be attributed to large amount of human consumption of local water. However, the results showed that the aims of restoring Tianjin wetlands cannot be achieved fully by relying solely on local water resources. It is necessary to consider a combination of external sources of water and using artificial recharge from reclaimed water.     

Groundwater Recharge Assessment for the Kalahari Catchment of North-eastern Namibia and North-western Botswana with a Regional-scale Water Balance Model

Groundwater is the only source of drinking water for the inhabitants of the Kalahari. Thus understanding spatial and temporal variations in groundwater recharge is very important and a regional-scale water balance model has therefore been set up for a 209,149 km² catchment in north-eastern Namibia and north-western Botswana. The model has a spatial resolution of 1.5 × 1.5 km, daily model time-steps, and climatic input parameters for 19 years are used. The distributed, GIS-based, process-oriented, physical water balance model (MODBIL) used in this study considers the major water balance components: precipitation, evapotranspiration, groundwater recharge, and surface runoff/interflow. Mean precipitation for the study area is 409 mm a⁻¹, while mean actual evapotranspiration is 402 mm a⁻¹ and mean groundwater recharge is 8 mm a⁻¹ (2% of mean annual precipitation). The recharge pattern is mainly influenced by the distribution of soil and vegetation units. Groundwater recharge shows a high inter- and intra-annual variability, but not only the sum of annual precipitation is important for the development of groundwater recharge; a large amount of precipitation in a relatively short period is more important. Published independent data from the Kalahari in Namibia, Botswana and the Southern African region under similar climatic conditions are used to verify the modelling results.     

Assessment of Groundwater Potential in a Semi-Arid Region of India Using Remote Sensing,GIS and MCDM Techniques

Remote sensing (RS) and geographic information system (GIS) are promising tools for efficient planning and management of vital groundwater resources, especially in data-scarce developing nations. In this study, a standard methodology is proposed to delineate groundwater potential zones using integrated RS, GIS and multi-criteria decision making (MCDM) techniques. The developed methodology is demonstrated by a case study in Udaipur district of Rajasthan, western India. Initially, ten thematic layers, viz., topographic elevation, land slope, geomorphology, geology, soil, pre- and post-monsoon groundwater depths, annual net recharge, annual rainfall, and proximity to surface water bodies were considered in this study. These thematic layers were scrutinized by principal component analysis technique to select influential layers for groundwater prospecting. Selected seven thematic layers and their features were assigned suitable weights on the Saaty’s scale according to their relative importance in groundwater occurrence. The assigned weights of the thematic layers and their features were then normalized by using AHP (analytic hierarchy process) MCDM technique and eigenvector method. Finally, the selected thematic maps were integrated by weighted linear combination method in a GIS environment to generate a groundwater potential map. Thus, four groundwater potential zones were identified and demarcated in the study area, viz., ‘good’, ‘moderate’, ‘poor’ and ‘very poor’ based on groundwater potential index values. The area falling in the ‘good’ zone is about 2,113 km² (17% of the total study area), which encompasses major portions of Sarada, Salumber, Girwa, Dhariawad, and Mavli blocks of the study area. The northeast and southwest portions along with some scattered patches fall in the ‘moderate’ zone, which encompasses an area of 3,710 km² (about 29%). The ‘poor’ zone is dominant in the study area which covers an area of 4,599 km² (36% of the total area). The western portion and parts of eastern and southeast portions of the study area are characterized as having ‘very poor’ groundwater potential, and this zone covers an area of 2,273 km² (18%). Moreover, in the ‘good’ zone, the mean annually exploitable groundwater reserve is estimated at 0.026 million cubic metres per km² (MCM/km²), whereas it is 0.024 MCM/km² in the ‘moderate’ zone, 0.018 MCM/km² in the ‘poor’ zone, and 0.013 MCM/km² in the ‘very poor’ zone. The groundwater potential map was finally verified using the well yield data of 39 pumping wells, and the result was found satisfactory.     

Towards better water security in North China

Water shortages and related environmental degradation in North China are major issues facing the country. As runoff from the mountainous parts of the region steadily decrease and water resources become overcommitted, serious water and environmental problems have resulted. These include drying-up of rivers, decline in groundwater levels, degradation of lakes and wetlands, and water pollution. Thus, 4000,km of the lower reaches of the Hai River – some 40% of its length – has experienced zero flows and, as result, parts of this river have become an ephemeral stream. The area of wetland within the Basin has decreased from 10,000,km² at the beginning of 1950s to 1,000km² at present. Over-extraction of groundwater occurs beneath 70% of the North China Plain, with the total groundwater over-extraction estimated at 90,billion m³. Thus, problems of water shortage and related environmental issues in North China have become the most significant limiting factors affecting sustainable development in this important region of China. This paper addresses the water security issues facing North China in the 21st Century using the Hai River basin as an example. We describe hydrologic cycles under changing environments, water-saving agriculture, assessment of water resource security, and efforts towards achieving integrated catchment management.     

Groundwater Rise Problem and Risk Evaluation in Major Cities of Arid Lands – Jedddah Case in Kingdom of Saudi Arabia

Arid lands are in the need of additional water supply but water transportation from outside of the natural hydrological cycle causes the groundwater to rise within the urban areas. Additional water supply from surrounding areas or through the desalination plants provides comfort in domestic activities but after the usage, its disposition is necessary in an efficient manner. Unfortunately, arid region cities have neither sufficient nor efficient sewage system. Consequently, the water returned to surface cesspools and leakages from insufficient sewage system makes internal groundwater recharge within the urban area. Additionally, water supply system leakages further raise the groundwater level. Deterioration in water quality becomes a potential danger for the infrastructure and foundations. Surface depressions in the city may be flooded due to groundwater level rise and at times bed smells occur at various parts of the city. In this paper, a quantitative method is followed to assess groundwater level rise risks in addition to the few chemical risks associated with sulfate and chloride solids. It is observed that each one of these variables has different probability distribution function and expose risk maps with different features.     

Natural recharge to sustainable yield from the barind aquifer: a tool in preparing effective management plan of groundwater resources.

This paper presents the results of water balance study and aquifer simulation modeling for preliminary estimation of the recharge rate and sustainable yield for the semi arid Barind Tract region of Bangladesh. The outcomes of the study are likely to be useful for planning purposes. It is found from detailed water balance study for the area that natural recharge rates in the Barind Tract vary widely year to year. It may have resulted from the method used for the calculation. If the considered time interval had been smaller than the monthly rainfall, the results could have been different. Aquifer Simulation Modeling (ASM) for the Barind aquifer is used to estimate long-term sustainable yield of the groundwater considering limiting drawdown from the standpoint of economic pumping cost. In managing a groundwater basin efficiently and effectively, evaluation of the maximum annual groundwater yield of the basin that can be withdrawn and used without producing any undesirable effect is one of the most important issues. In investigating such recharge rate, introduction of certain terms such as sustainable yield and safe yield has been accompanied. Development of this area involves proper utilization of this vast land, which is possible only through ensured irrigation for agriculture. The Government of Bangladesh has a plan to develop irrigation facilities by optimum utilization of available ground and surface water. It is believed that the groundwater table is lowering rapidly and the whole region is in an acute state of deforestation. Indiscriminate groundwater development may accelerate deforestation trend. In this context estimation of actual natural recharge rate to the aquifer and determination of sustainable yield will assist in proper management and planning of environmentally viable abstraction schemes. It is revealed from the study that the sustainable yield of ground water (204 mm/y) is somewhat higher than the long-term annual average recharge (152.7 mm) to the groundwater reservoir. The reason behind this is that the rivers within and around the Barind Tract might have played the role of influent rivers.     

Cost-effective Approaches for Sustainable Groundwater Management in Alluvial Aquifer Systems

The consequences of unsustainable use of groundwater are becoming increasingly evident worldwide, particularly in developing nations. Groundwater management is a serious problem in many parts of the world. The prime concern is how to achieve groundwater sustainability. Artificial recharge techniques coupled with water harvesting hold a great promise for groundwater sustainability. The main intent of this paper is to highlight salient cost-effective and easy-to-use methods for augmenting groundwater resources in the alluvial hydrogeologic setting. Based on the intensive field investigation in a groundwater basin of Japan, three low-cost and easy-to-implement recharge techniques are suggested for alluvial aquifer systems, viz., augmentation of river flow, recharge through irrigation/drainage canals, and recharge from paddy fields. The source of recharge water for these recharge techniques is surface water supply. The efficacy of these methods or approaches has been demonstrated. It is emphasized that such cost-effective methods of groundwater recharge are key to sustainable groundwater management in both developing and developed countries. These methods must not be overlooked in the midst of sophisticated and highly expensive methods.     

石川河河谷区地下水人工补给潜力与补给方式

为实现石川河地下水位的有效回升进而维持采补平衡,需在该区实施地下水人工补给工程,并确定合理的 补给位置及有效的补给方式。选取地下水埋深、坡度、含水层厚度、含水层渗透系数、与环境敏感区距离和给水 度 6 个指标,运用空间分析技术对人工补给地下水地点适宜性进行评价;在此基础上建立三维地质模型分析典型 人工补给潜力区的地层结构,探索可行的地下水人工补给方式。结果表明：适宜进行人工补给的高潜力和较高潜 力区域主要分布在研究区中部及东南部,面积达 48.01?km2,占研究区总面积的 32.0%。建议：在石川河河道中上 游高潜力和较高潜力区域的北部修建地表入渗池或渗坑;在河道中上游高潜力和较高潜力区域南部和河道中下 游的较高潜力区域布设反滤回灌井群;可沿石川河河道中上游高潜力与较高潜力区域之间布置一条长约 4.5?km 的渗渠,利用河道进行入渗补给。研究结果可为地下水库的修建提供参考。     

Quantitative Assessment of Regional Rock Aquifers, South-Western Quebec, Canada

The population of the St. Lawrence Lowlands platform in south-western Quebec, Canada, is heavily dependent on groundwater. The present study summarizes the quantity, quality and sustainability estimations of the groundwater resources found mainly in sedimentary rock aquifers. Results show that the regional groundwater flow in the considered domain of 1,500 km² is 97.7 Mm³/y with: 86.6% infiltration from precipitation, 9.6% inflow from neighboring aquifers, and 3.8% induced recharge. The regional sustainability is defined with simulated drawdowns from uniform withdrawal scenarios. The current withdrawal rate of 18 Mm³/y results in median drawdown of 0.6 m, compared to pre-development conditions. This drawdown is situated well in the sustainable range, an indication that regional aquifers are not overexploited. Hypothetical pumping rate of 24 Mm³/y resulting in an average drawdown of 2.2 m is estimated as sustainable limit. Increasing exploitation from 24 to 51 Mm³/y would need tight control and planning. Pumping rates beyond 51 Mm³/y are judged not sustainable as regional drawdowns become high, ∼8 m. The water levels in recharge areas are the most sensitive to groundwater extraction. Combining drawdown maps, groundwater quality zones, and aquifer vulnerability to surface contamination delineated the areas most suitable for future groundwater developments.     

Exploring the future impacts of urbanization and climate change on groundwater in Arusha,Tanzania

ABSTRACT

We combine satellite imagery, urban growth modelling, groundwater modelling and hydrogeological field expeditions to estimate the potential impacts in 2050 of rapid urbanization and climate change on groundwater in Arusha, Tanzania, and by extension similar areas in Sub-Saharan Africa. Our analysis suggests that a reduction of groundwater recharge by 30–44% will cause groundwater levels to drop by up to 75 m, mainly due to increased evapotranspiration and to an expansion in paved surface. If this scenario becomes reality, we predict that wells will run dry, creating health, social and environmental risks.     

Total Urban Water Cycle Models in Semiarid Environments��Quantitative Scenario Analysis at the Area of San Luis Potosi, Mexico

Systems view thinking and holistic urban water cycle concepts are increasingly called upon for integrated analysis of urban water systems to mitigate water stress in large urban agglomerations. However, integrated analysis is frequently not applied due to the inherent complexity, limitations in data availability and especially the lack of guidelines and suitable software tools. The paper presents the application of the total urban water balance model UVQ to the City of San Luis Potosi (1.2 Mio inhabitants) under the arid conditions of Northern Mexico. UVQ is a lumped parameter model which describes water and contaminant flows from source to sink in urban areas and includes all water types such as rainwater, imported water, surface runoff, wastewater and groundwater. The results were especially useful for spatially explicit groundwater recharge calculation in urban areas. A range of urban water scenarios, including different supply strategies and the effect of externalities such as demand change, were simulated and compared to a calibrated baseline scenario. The analysis demonstrated that shallow urban groundwater resources can substantially mitigate problems of water scarcity and overexploitation of deep aquifers if appropriate water quality protection or fit-for-use paradigms are put into place. The modelling exercise delivers relevant information for the decision making process and identifies the most relevant shortcomings in current monitoring systems. This represents a key step on the path to water sensitive and sustainable urban development, including the urban aquifers which have been neglected in the management policy of most cities of the Mexican arid zone.     

石川河地下水库建库条件分析及地下水位动态预测

通过分析富平县石川河河谷阶地区的自然地理、气象、水文、地质等条件以及地下水资源开发利用情况,建立了水文地质结构三维模型,论证了建立石川河地下水库的可行性,初步计算了地下水库库容约为4.95亿m~3。利用Visual MODFLOW软件建立了地下水库库区的地下水数值模型,预测了不同降水和开采条件下,进行人工回灌0.52亿m~3/a、10年后地下水库库区的地下水位变化情况。结果表明,库区内的地下水位将大范围的抬升,大部分地区与1959年的水位相近,可基本满足当地的用水需求。     

Characterization of a Regional Aquifer System in the Maritimes Basin,Eastern Canada

A regional hydrogeological study was carried out in the Maritimes provinces, in one of the main aquifer systems in Canada. The study area covers a land surface of 10,500 km², of which 9,400 km² is over Carboniferous and younger rocks. The sedimentary fractured bedrock is composed of a sequence of discontinuous strata of highly variable hydraulic properties, and is overlain by a thin layer of glacial till (mostly 4 to 8 m). Depending on areas, 46 to 100% of the population relies on groundwater for water supply. Almost all residential wells are shallow (28 m on average) open holes that are cased only through the surficial sediments. This paper describes a regional hydrogeological investigation based on targeted fieldwork, the integration of a wide variety of existing multisource datasets and groundwater flow numerical modelling. The aim of this paper is to present the current state of understanding of the aquifer system in a representative area of the Maritimes Basin, along with the methodology used to characterize and analyze its distinct behaviour at the regional, local and point scales. This regional hydrogeological system contains confined and unconfined zones, and its aquifer lenticular strata extend only a few kilometers. Preferential groundwater recharge occurs where sandy tills are present. The estimated mean annual recharge rate to the bedrock aquifers ranges between 130 and 165 mm/year. Several geological formations of this Basin provide good aquifers, with hydraulic conductivity in the range of 5 × 10⁻⁶ to 10⁻⁴ m/s. Based on numerical flow modelling, faults were interpreted to play a key role in the regional flow. Pumping test results revealed that the aquifers can locally be very heterogeneous and anisotropic, but behave similarly to porous media. Work performed at the local scale indicated that most water-producing fractures generally have a sub-horizontal dip along a north-east (45°) strike.     

Estimating Land Use Impacts on Regional Scale Urban Water Balance and Groundwater Recharge

Anthropogenic activities have exerted increasingly large-scale influences on terrestrial ecological systems from the past century, primarily through agriculture; however, the impact of such changes on the hydrologic cycle is poorly understood. As one of the important land use (LU) in the coastal Dogo Plain of the Seto Inland Sea, Japan, paddy fields have been decreasing with the increase in urbanization in recent decades. As the main source of water in the Dogo Plain, groundwater plays an important role in providing people with fresh water and contributing to stream base flow. The purpose of this study is to analyze the water resource and evaluate the effect of LU change on groundwater table fluctuation in this coastal plain. Firstly, the observations of groundwater table and the investigation of water balance were carried out in this alluvial plain. Then, a distributed four-block three-layer water balance model was employed to analyze the groundwater table fluctuation with response to the change of paddy field area. Moreover, the role of paddy field in recharging groundwater in the basin has been clarified. Results show that groundwater table depends not only on rainfall and discharge from rivers, but also on irrigation water and topology of the study area. The net groundwater recharge was positive in irrigation periods whereas that in non-irrigation periods was nearly equal to zero or negative. The results of this study would be helpful to the urban development policy and land use planning decision.     

GIS-Based Groundwater Management Model for Western Nile Delta

The limited availability of renewable fresh water is a major constraint on future agriculture and urban development in Egypt. The main water resource that Egypt has been depending on is the River Nile. Nowadays, the role of groundwater is steadily increasing and will cover 20% of the total water supply in the coming decades especially in the reclaimed areas along the desert fringes of the Nile Delta and Valley. Abstraction from groundwater in Egypt is dynamic in nature as it grows rapidly with the expansion of irrigation activities, industrialization, and urbanization. One of these areas is the Western Nile Delta in which the groundwater is exploited in many localities. To avoid the deterioration of the aquifer system in this area, an efficient integrated and sustainable management plan for groundwater resources is needed. Efficient integrated and sustainable management of water resources relies on a comprehensive database that represents the characteristics of the aquifer system and modeling tools to achieve the impacts of decision alternatives. In this paper, a GIS-based model has been developed for the aquifer system of the Western Nile Delta. The GIS provides the utilization of analytical tools and visualization capabilities for pre-and post-processing information involved in groundwater modeling for the study area. The developed model was calibrated for steady state and transient conditions against the historical groundwater heads observed during the last 20 yr. The calibrated model was used to evaluate groundwater potentiality and to test two alternative management scenarios for conserving the aquifer system in Western Nile Delta. In the first scenario, reducing the surface water inflow while increasing the annual abstraction from groundwater by about 450 million m³ and improving the irrigation system could increase the net aquifer recharge by about 5.7% and reduce the aquifer potentiality by about 91%. Constructing a new canal as a second management scenario could increase the annual aquifer potentiality by about 23%. The GIS-based model has been proven to be an efficient tool for formulating integrated and sustainable management plan.     

Statistical Approach for Comprehensive Planning of Watershed Development Through Artificial Recharge

The purpose of the study is to demonstrate that cross-correlation analyses can contribute to the artificial recharge study in regional level of shallow aquifer. Correlations between hydrologic time series data were analyzed to identify the hydrogeologic location for potential artificial recharge in district Surat, Gujrat, India. The natural groundwater-level fluctuations and rainfall data were used for the analyses. The effective development of groundwater resources is essential for a country like India. India receives a good amount of average annual rainfall (114?cm) but most of its part goes waste as runoff. Over exploitation of groundwater due to increasing population is an additional cause of water crisis that results in the reduction in per capita availability of water in the country. Artificial recharge is essential for effective development of groundwater resources. An effort has been made to evaluate the suitable recharge zone considering rainfall by arresting runoff to restore groundwater conditions using a statistical technique. Groundwater system in a basaltic terrain where the top weathered regolith forms shallow aquifer the water table variation is directly influenced with temporal rainfall variation. Understanding of this relation is of critical importance to management of groundwater resources. A diagnostic relationship between recharge time series and water level time series is used to serve the purpose to determine the best site for groundwater recharge.     

近40年三江平原典型区土地利用变化及其对地下水的影响

三江平原是我国重要的商品粮基地和粮食战略储备基地,地下水作为该地区的主要灌溉水源,其动态备受关注。选取三江平原典型区1980、1990、2000、2010及2018年五期遥感影像数据进行土地利用变化特征分析,探究土地利用类型变化对地下水位埋深的影响和城市化进程、耕地面积变化对流域水均衡状态的影响。结果表明:近40年来水田与城镇用地的面积和周长存在显著的分形特征,稳定性指数由强—弱—强,两种土地利用类型的重心在近40年内发生明显迁移且迁移方向主要为西南—东北—西南,其直接影响流域水均衡状态。土地利用类型的改变使得部分地区地下水补给恢复较慢,造成地下水位埋深不同程度地增大。城市化发展对大气降水入渗补给量影响相对较小,耕地面积变化对灌溉回归补给量影响显著。研究结果可为构建更准确的三江平原典型区地下水数值模型提供科学依据,为三江平原地下水的可持续开发利用提供理论参考。     

Groundwater Exploitation and Its Impact on the Environment in the North China Plain

Abstract

The North China Plain (NCP) is one of China's most important social, economic, and agricultural regions. Currently, the Plain has 17,950 thousand ha of cultivated land, 71.1 percent of which is irrigated, consuming more than 70 percent of the total water supply. Increasing water demands associated with rapid urban and industrial development and expansion of irrigated land have led to overexploitation of both surface and the ratio of groundwater resources, particularly north of the Yellow River. In 1993, the ratio of groundwater exploitation to recharge in many parts of the NCP exceeded 1.0; in some areas, the ratio exceeded 1.5. Consequently, about 1.06 million ha of water-short irrigated areas in the NCP also have poor water quality. Persistent groundwater overexploitation in the northern parts of the NCP has resulted in water-level declines in both shallow and deep aquifers. According to data from 600 shallow groundwater observation wells in the Hebei Plain, the average depth to water increased from 7.23 m in 1983 to 11.52 m in 1993, indicating an average water-table decline of 0.425 m/year. Water table declines are not uniformly distributed throughout the area. Depletion rates are generally greatest beneath cities and intensively groundwater-irrigated areas. Water-table declines have also varied over time. With the continued decline of groundwater levels, large depression cones have formed both in unconfined and confined aquifers beneath the Hebei Plain. Groundwater depletion in the NCP has severely impacted the environment. Large tracts of land that overlie cones of depression have subsided, seawater has intruded into previously freshwater aquifers in coastal plains, and ground-water quality has deteriorated due to salinization, seawater intrusion, and untreated urban and industrial wastewater discharge. In order to balance groundwater exploitation with recharge, the major remedial measures suggested are to strengthen groundwater management, to raise water use efficiency, to adjust the water-consumed structure, and to increase water supply