再生水灌区地下水防污性能区划模型的建立与验证

为促进地下水水资源保护和利用,根据研究区域的特点以及地下水防污性能的影响因素,基于DRASTIC模型,选用以下6个因子：地下水水位埋深、降雨入渗补给量、表层土壤类型、包气带岩性、含水水力传导度以及土地利用类型建立了再生水灌区地下水特殊防污性能区划模型。采用地理信息系统GIS技术和内梅罗指数法,绘制研究区域地下水综合污染指数分布空间图,并且探讨了防污性能区划的验证方法以及等级划分标准。结果表明：地下水综合污染指数与研究区域的防污性能具有很好的相关性（R2=0.9591）,采用DRASTIC模型评价地下水特殊防污性能是可行的,可为再生水灌区地下水的保护以及利用规划提供重要借鉴。     

A Case of Hydrochemical Characterization of an Alluvial Aquifer Influenced by Human Activities

21 physico-chemical parameters have been determined in 47 groundwater samples collected in October 1994 from the alluvial aquifer of the Pisuerga river, located at the north-east of Valladolid (north-western Spain). Conventional hydrochemical methods and multivariate statistical analysis have been used to discriminate natural phenomena and pollution processes in the area. It has been demonstrated the existence of a heterogeneity in groundwater mineral contents related to anthropic actions such as irrigation, source of irrigation water and location of polluting sources. This study demonstrates the existence of two sub-units in the alluvial aquifer (left and right river banks) with different hydrochemical characteristics, and identifies three different singular areas in the left bank. Groundwater from this bank showed higher levels of dissolved ions caused by concentration processes derived from the predominant use of groundwater for crop irrigation, whilst in the right bank of the aquifer less saline water from canals is used. Degradation of groundwater quality has been observed in some areas of the left aquifer sub-unit (north, Santovenia and south-central sites) where anomalous high concentrations of sulphate, sodium, chloride and nitrate were measured, and can be related to the presence of potentially polluting sources such as leachates from industrial waste disposals, sewage effluents and use of organic and inorganic fertilizers.     

再生水灌区调蓄工程对地下水盐分的影响

为了对再生水灌区调蓄工程选址提供依据,该文通过建立5个不同深度监测井研究了再生水灌区调蓄工程对地下水盐分的影响,再生水经包气带入渗后渗滤液氯离子、全盐、总硬度含量有所增加,12 m包气带厚度对总氮、总磷去除率达到97.3%和99.0%以上,但是渗滤液中全盐、总氮、氮磷、总硬度等含量指标接近地下水背景值,未发现再生水调蓄工程蓄水导致地下水水质发生明显变化,说明研究区域再生水渗滤进入地下水对盐分的影响与其他补给水源的影响效果无显著差异。再生水灌区调蓄工程应建设在具有包气带岩性粗细相间、防污性能较好的区域。     

河套灌区井渠结合膜下滴灌土壤盐分演化规律

针对内蒙古河套灌区井渠结合的问题,基于SaltMod模型建立井灌区和渠灌区水盐均衡模型,并引入含水层侧向交换量对模型进行改进,利用隆胜井渠结合试验区15 a水盐观测资料对改进的模型进行率定和验证,采用验证后的模型分析了隆胜井渠结合区在现状条件下以及在井渠结合膜下滴灌推广实施后区域的土壤盐分演化规律。结果表明,现状条件下隆胜井渠结合区土壤盐分基本稳定,尤其是渠灌区根系层盐分基本稳定,保持在较低水平,可以在长时期内满足作物生长的需求。当推广井渠结合膜下滴灌后,井灌区的生育期灌溉定额和地下水埋深对其灌溉用地根系层土壤盐分积累的影响较小,而地下水矿化度与秋浇频率的影响较大。对于井灌区,建议采用黄河水2年1次进行秋浇压盐,可以长期将土壤全盐维持在3 g/kg以下,以满足作物生长需求。     

季节性冻融区井渠结合灌域地下水动态预报

该文以河套灌区永济灌域为研究对象,建立考虑冻融影响的分段式水均衡模型,预报12种井渠结合节水情景的地下水动态响应。结果表明:冻融期间气温对地下水埋深的影响在时间上滞后46.5 d,两者相关关系明显;地下水开发利用越多、秋浇采用黄河水的比例越小,节水规模越大,同时地下水位下降越明显。12种节水情景中,节水规模占现状引水量的5.7%~15.5%,全灌域平均地下水埋深增加0.05~0.24 m,井渠结合区地下水埋深增加0.16~0.38 m;灌域引黄水量与地下水埋深关系用二次函数进行拟合,决定系数R~2达到0.88以上;灌溉水利用效率的提高以及地下水位下降引起潜水蒸发的减小是井渠结合节水的实质。分析结果表明,考虑冻融影响的水均衡模型简单实用,可为中国西北干旱半干旱地区开展井渠结合地下水响应预报提供参考。     

Tracing Pharmaceuticals in the Unsaturated Zone (10 pp)

Background, Aim and Scope   One of the first occurrences of pharmaceutically active compounds in groundwater was reported from the sewage irrigation farms south of Berlin. At these sewage irrigation farms treated sewage effluent passed the soil and unsaturated zone before reaching the aquifer. Clofibric acid was detected in pore water from soils of those sewage irrigation farms in concentrations between 65 ng/L and 1430 ng/L. The aim of this study was to investigate the transport behavior of regularly detected clofibric acid, diclofenac, ibuprofen, and propyphenazone under conditions comparable to those at the sewage irrigation farms in a multiple compound sand column laboratory experiment. Materials and Methods   Sediment column experiments were conducted to study the transport of pharmaceuticals in the unsaturated zone. The migration was measured in fine to medium grained sand and leaching solution containing 1 mg/L of pharmaceutically active compounds and 61 mg/L of the tracer lithium chloride (LiCl). For the analysis of the pharmaceutical compounds the water samples were adjusted to a pH value of 2 and then extracted by solid-phase extraction (SPE). Before extraction, the samples were spiked with a surrogate standard for analytical quality control. The sample extracts were analyzed by capillary gas chromatography-mass spectrometry (GC-MS) with selected ion monitoring (SIM). Depending on the sample volume (100 to 200 mL) and the matrix, the limits of detection were between 1 and 10 ng/L, and the limits of quantitation were between 5 and 25 ng/L. Analysis for calcium, magnesium and lithium were carried out using a 'Trace Scan' ICP-AES from Thermo Jarrel Ash. Sodium, potassium, iron and manganese were analyzed using a Philips PU 9400 flame AAS. Analysis of anions was performed on a Dionex ion chromatograph DX 120. Results   At the sewage irrigation farms the average concentrations of clofibric acid in the unsaturated zone declined from higher values near ground surface (480 ng/L) to lower values near the groundwater table (65 ng/L). From the pharmaceuticals analyzed only clofibric acid, primidone and propyphenazone could be analyzed in the first (upper) aquifer at the sewage irrigation farms. All other pharmaceuticals could neither be detected in the first aquifer nor in the deeper aquifers. Breakthrough curves from soil column experiments revealed no transformation and no retardation for clofibric acid, whereas transformation of diclofenac was so high (79%) that no retardation factor could be calculated. Ibuprofen was significantly transformed (37%), transformation of propyphenazone (17%) was quite low and retardation (Rf = 2.05) was in the range of previously conducted column experiments. Discussion   The results confirm previously conducted experiments with clofibric acid where this compound was identified as highly mobile and persistent. The results that diclofenac and ibuprofen are significantly transformed where unexpected as other studies exhibited much lower transformation under saturated conditions at least for diclofenac. However, lower pH values and higher oxygen contents in the unsaturated zone compared to the aquifer may explain this observed high transformation of these compounds at the column experiments. Conclusions   We conclude that irrigation with sewage effluent containing the compounds used in our experiments will lead to an input into groundwater of clofibric acid, whereas diclofenac and ibuprofen will most likely be transformed during the passage. Propyphenazone will be retarded but will most likely occur in groundwater. These results from the column experiments coincide very well with the occurrence of the pharmaceuticals clofibric acid, primidone, and propyphenazone in the first aquifer. Recommendations and Perspective  : The results underline the need to study the sorption of pharmaceuticals on various materials. e.g. organic matter, surfaces at pH values occurring in the unsaturated zone. Future field studies will also include the investigation of desorption behavior in the unsaturated zone.     

Arsenic Concentrations in Groundwater,Soils, and Irrigated Rice in Southwestern Bangladesh

Arsenic (As) poisoning of groundwater in Bangladesh has become a major environmental and health issue. The extensive use of groundwater in irrigation of rice has resulted in elevated As in soils and crops. A study was undertaken to determine As concentrations in groundwater, soils, and crops in 16 districts of southwestern Bangladesh. Groundwater samples were collected from shallow-tube and hand-tube wells (STW and HTW) used for irrigation and drinking water. Soil and rice plants were sampled from the command area of the tube wells. Arsenic concentrations were determined using an atomic absorption spectrometer equipped with flow injection hydride generator. Groundwater samples contained <10 to 552 μg As L^?1. Arsenic concentrations in 59% of STW samples exceeded 50 μg As L^?1, the national standard for As in drinking water. Unlike groundwater, most of the surface water samples contained <10 μg As L^?1. Concentrations of As in the soils from the command area of the tube wells ranged from 4.5 to 68 mg kg^?1. More than 85% of the soils contained <20 mg As kg^?1. The mean As concentration in the rice grain samples was 0.23 mg kg^?1, which is much less than the maximum food hygiene standard. A positive relationship was observed between groundwater and soil As, implying that soil As level increases as a result of irrigation with contaminated water. However, irrigation water As did not show any relation with rice grain As. The findings suggest that surface water bodies are a safe source of irrigation water in the As-contaminated areas.     

lead contamination of GROUNDWATER in an INDUSTRIAL complex

The objectives of this study were to investigate Pb contamination of a shallow groundwater aquifer underneath an industrial complex and Pb chemical forms that may be found in the study area. Concentrations of Pb in the groundwater samples ranged between 0.04 to 1570.12 µg L^-1 (10^-9.4 to 10^-5.1 mole L^-1), with an average of 88.2 µg L^-1 (10^-6.4 mole L^-1). The results of analysis of variance showed that sampling locations had significantly (p <0.05) affected Pb concentrations in the groundwater samples. Contour map of Pb concentrations and Pb/Cl ratios indicated that Pb contamination of groundwater could be associated to the seepage of irrigation water, corrosion of buried metallic structure (largely of iron), and leachate from the industrial dust pile. Thermodynamic modeling approach was used to speciate total Pb concentrations in the groundwater samples. The results of these computations revealed that, in the very dilute groundwater (salinity < 1 parts per thousand, i.e., ppt), Pb²⁺ and Pb-OH complexes were the most significant chemical forms. Groundwater salinities between 1 to 5 ppt, Pb²⁺, Pb-OH, Pb-Cl, Pb-HCO₃, and Pb-SO₄ were present in appreciable concentrations, depending on their respective anionic concentrations. Over 80% of the total Pb in water was present in Pb-Cl complexes in groundwater samples with salinities >40 ppt. A comparison of the calculated activities of Pb²⁺ and the thermodynamic solubility isotherms of Pb minerals suggested that mineral Pb(OH)₂(c) was too soluble to precipitate in these water samples. The distribution trend in Pb²⁺ activities do not support equilibrium with Pb₃(PO₄)₂(c). Formation of PbCO₃(c) and Pb₂CO₃Cl₂(c) in the groundwater samples appeared to be the most logical option. From the foregoing, it was concluded that Pb-CO₃ minerals can limit Pb solubility in saline groundwaters.     

华北农区浅层地下水硝酸盐分布特征及其空间差异性

华北平原地下水硝酸盐污染备受关注,然而受地貌类型、土地利用、土壤结构、含水层水文地质条件等因素差异性的影响,对区域尺度上农区浅层地下水硝酸盐污染程度和特征尚没有统一定论。本文通过综述过去华北平原地下水硝酸盐污染程度的相关研究,并结合近年来对华北平原农业种植区浅层地下水硝酸盐研究所取得的认识,指出补给源区(太行山低山丘陵区)、山前平原和低平原3个典型地貌类型区浅层地下水硝酸盐研究存在的问题:补给源区土地利用变化多样、土壤和含水层渗透性好,要重视对源区氮输入的控制,加强低山丘陵区气候变化对水文过程和氮迁移过程影响机制的研究;山前平原区是农业高产区,地下水埋深较深且包气带厚度大,较高的浅层地下水硝酸盐浓度除了与点源、污水渗漏以及污水灌溉等直接影响因素有关外,农田过量肥料施用对地下水硝酸盐影响的程度、水氮迁移路径以及未来潜在风险是农区地下水硝酸盐研究中亟需关注的问题;低平原区较细的土壤沉积结构减缓了氮向下迁移的速度,但地下水埋深较浅,二者的制约关系决定了地下水硝酸盐浓度,因此应在理解地表水-土壤-地下水转化关系的基础上评估地下水硝酸盐污染的风险。     

利用作物水盐生产函数和土壤水盐动态模型制定咸水灌溉制度

Using a crop-water-salinity production function and a soil-water-salinity dynamic model, optimal irrigation scheduling was developed to maximize net return per irrigated area. Plot and field experiments were used to obtain the crop water sensitivity index, the salinity sensitivity index, and other parameters. Using data collected during 35 years to calculate the 10-day mean precipitation and evaporation, the variation in soil salinity concentrations and in the yields of winter wheat and cotton were simulated for 49 irrigation scheduling that were combined from 7 irrigation schemes over 3 irrigation dates and 7 salinity concentrations of saline irrigation water （fresh water and 6 levels of saline water）. Comparison of predicted results with irrigation data obtained from a large area of the field showed that the model was valid and reliable. Based on the analysis of the investment cost of the irrigation that employed deep tube wells or shallow tube wells, a saline water irrigation schedule and a corresponding strategy for groundwater development and utilization were proposed. For wheat or cotton, if the salinity concentration was higher than 7.0 g L^-1 in groundwater, irrigation was needed with only fresh water; if about 5.0 g L^-1, irrigation was required twice with fresh water and once with saline water; and if not higher than 3.0 g L^-1, irrigation could be solely with saline water.     

猪场废水灌溉对地下水中钾、钙、钠、镁含量的影响

应用猪场废水处理工程中产出的厌氧水不同灌溉量和3个处理阶段出水与地下水按体积比1∶5混合对冬小麦-夏玉米轮作系统进行3年的小区灌溉试验,监测地下水的总矿化度及钾、钙、钠、镁等含量的变化。结果表明：（1）地下水中钾含量在厌氧水不同灌溉量条件下呈现高量厌氧水（Ha）〉中量厌氧水（Ma）〉低量厌氧水（La）的变化趋势,在混水灌溉处理地下水中钾含量均呈厌氧水与地下水1∶5混合（Tag）〉原水与地下水1∶5混合（Tog）〉仿生态塘水与地下水1∶5混合（Teg）的变化趋势;（2）地下水中钠、钙、镁含量大致呈现低量厌氧水（La）〉中量厌氧水（Ma）〉高量厌氧水（Ha）,仿生态塘水与地下水1∶5混合（Teg）〉原水与地下水1∶5混合（Tog）〉厌氧水与地下水1∶5混合（Tag）的变化趋势。     

Wellhead Protection Area Delineation Using the Analytic Element Method

Wellhead protection areas (WHPAs) were delineated around three water supply wells in Urmia Plain, Urmia City, Iran. WhAEM2000 (V.2.1.0) computer model based on the analytic element method was used and two years time of travel WHPAs were delineated for pumping wells drilled in the basin of Shahr-Chai River located in Urmia Plain. The steady-state flow was applied for unconfined aquifer. This feature included the main surface water features (rivers and lake), recharge rate due to precipitation, irrigation and periodical tributaries, and inhomogeneity to represent the western area of the plain, having different characteristics. The model was subsequently calibrated by means of the observed piezometric heads as test points. In confined aquifer the groundwater does not have interaction with the surface waters and no recharge penetrates into the aquifer. Hence, uniform flow was applied to create a new model. In confined model two parameters (hydraulic gradient and direction of the flow) were then evaluated using three points method. To overcome uncertainties related to the aquifer parameters and lack of sufficient piezometric data, the parameters sensitivity analysis and the hypothesis testing method were used and the final WHPAs were reasonably delineated for the wells. Results showed that the shapes of the WHPAs for wells in unconfined aquifer are longer and narrower than those in confined aquifer.     

地下水作用下微咸水灌溉对土壤及作物的影响

随着微咸水灌溉面积逐年增加,不合理的灌溉对土壤环境造成了不同程度的污染。该文采用大型蒸渗仪研究不同地下水埋深条件下微咸水灌溉夏玉米对土壤-作物系统环境因子的影响。研究结果表明：在地下水水位低于3 m地区进行微咸水灌溉,0～100 cm的土层内不会形成严重的积盐现象。当灌水水质为4 g/L时,灌水水质对土壤盐分环境的影响大于地下水埋深对其的影响。地下水埋深越深,夏玉米叶面积指数、株高及产量越小,且随灌溉水盐分水平的增加而减小,地下水埋深对夏玉米形态指标的影响大于盐分水平对其的影响。     

Aquatic Hazard Assessment of a Contaminated Surficial Aquifer Discharge into the Bush River,Maryland (U.S.A.)

An aquatic hazard assessment of contaminatedgroundwater in a surficial aquifer was conducted at Beach Pointwhich is located in the Edgewood Area of the U.S. Army Garrison,Aberdeen Proving Ground, Maryland. Toxicity was detected atvarious groundwater concentrations by seven of 10 toxicity testsystems exposed to a mixture of heavy metals and chlorinatedaliphatic hydrocarbons. When estimated maximum acceptabletoxicant concentrations (MATC) were established, the data foralgae, invertebrates, and fish suggested that the groundwaterwould not be harmful at a concentration of 10% groundwater byvolume. Likewise, no genotoxicity (Ames and SEC assays),development toxicity (FETAX), or chronic histopathology (9-monthfish test) occurred at 10% groundwater by volume.Near-field (ULINE model) and far-field (dye-tracer model)screening level dilution models were run to estimate the dilutionof the groundwater discharge plume from Beach Point into the BushRiver. The groundwater was considered to be a potentiallyexcessive hazardous material to the biota in the Bush River whena number of conservative assumptions regarding contaminantdistribution and discharge rate of the aquifer were used in thehazard assessment. By modeling the groundwater emanating fromBeach Point as the dilution of a discharge from a line diffuser,the potential water quality impacts were judged to be minimal ifState of Maryland surface water discharge criteria for a mixingzone were used for the discharge of groundwater to the Bush River.     

四川省简阳市地下水水化学特征及灌溉适宜性

[目的]对四川省简阳市地下水水化学特征与灌溉适宜性进行分析和评价,为合理开发该区地下水资源提供科学依据。[方法]利用Gibbs图、离子比值系数及多种统计分析方法,研究其浅表层与中深层地下水水化学特征,并将熵权理论与模糊物元法相结合,借助Matlab建立基于熵权的模糊物元模型,对地下水水质进行综合评价。[结果]研究区浅表层主要分布淡水,中深层主要为微咸水,由浅至深地下水水化学类型由HCO+3-Ca,HCO+3-Ca·Mg型转化为HCO_3-NaCa,HCO_3·SO_4~-Ca-Mg,SO_4-Na·Ca型。研究区地下水水化学成分主要受控于岩石风化作用,主要受岩盐、方解石、石膏、硅酸盐矿物的溶解及阳离子交替吸附作用的影响。浅表层地下水受人类活动影响比较明显;中深层地下水受深层盐卤水越流混合作用影响较明显。[结论]研究区浅表层地下水水质良好,适宜用做灌溉水源,由浅至深,地下水水质逐渐变差,中深层地下水不宜长期用于农业灌溉。     

成都平原典型样区浅层地下水水质调查与污染评价

[目的]开展成都平原区浅层地下水水质调查与污染评价,为该区域开展土壤和地下水资源保护、合理开发利用地下水资源提供理论依据。[方法]在成都平原典型样区采集了60个浅层地下水样,分析水样的pH值、溶解性总固体、总硬度、氯化物、氨氮、氟化物、硝酸盐、亚硝酸盐、硫酸盐、铁、锰等11项指标。利用层级阶梯评价法和主成分分析法对研究区浅层地下水水质进行评价,并用MapGIS绘制了水质综合评价图。[结果]研究区浅层地下水部分指标超标,尤其是硝酸盐污染较严重,其次是总硬度、铁和锰。[结论]研究区地下水质量总体较好,局部地区有一定程度污染。     

Monitoring and prognosis of regional water and salt

A system designed for monitoring and prognosis of regional water and salt (PWS), was developed to consist of a monitoring system, a group of models and an information system. PWS was developed and tested using a 253 km² portion of a monitored area of 487 km² established for observation of the surface water flow and quality, groundwater table and quality, soil water and salt regime in Quzhou county, Hebei Province. Predictive models for groundwater table location and quality were developed using basic principles of hydrodynamics and solved using finite element methods. A regional soil water model was developed based on a water balance approach, while a regional soil salinity models was developed by combining salt balance and expert identification methods. Submodels were integrated and applied seasonally, with satisfactory prediction results for the regional scale. The percentage of mean relative error for groundwater depth (m) and quality (g/l), water storage (mm) and salt storage (kg/m²) in the 0–1 m soil layer were 14.8, 13.1, 14.1 and 25.4%, respectively. The information system component of PWS, defined as PWSIS, was composed of four parts: the subsystems database, vector management, a system model, and information output. The predicted outputs were expressed as either tables or contour maps of groundwater table or depth and quality, grade maps of soil water and salt storage or drought/waterlogging and salinity status. Some key problems, such as how to expand the point data to a plane and how to determine the boundary of each grade on the map, were solved using “the point-to-plane expanding algorithm” and GIS techniques of digitizing and overlaying the grid maps concerned.     

华北平原灌溉农田的土壤水量平衡和水分利用效率

华北平原农业面临的主要问题是水资源短缺,地下水位持续下降。通过一维土壤水量平衡模型模拟了华北平原不同灌溉方式下农田耗水量和土壤水分深层渗漏的变化,并分析了作物的产量和水分利用效率。结果显示在正常的灌溉条件下,冬小麦季地下水的采补差额超过了200mm,某生育期一定程度的水分亏缺(返青期、拔节期或灌浆期)能明显减少冬小麦的耗水量,但没有明显减少作物的产量。因此,在一定程度上减少灌溉是可行的,但仍不能达到地下水资源的采补平衡。从长远来看,华北平原维持可持续的地下水灌溉开采,应减少冬小麦的种植面积、增加低耗水经济作物的比例。     

华北平原地下水压采区冬小麦种植综合效应探讨

华北平原冬小麦-夏玉米一年两熟种植模式为维护国家粮食安全发挥了重要作用。但冬小麦生长期正处于华北平原降水较少的干旱季节,实现高产依赖于灌溉,是华北平原地下水超采的主导因素之一。随着国家地下水限采政策的实施,在地下水超采区如何稳定冬小麦的种植面积和产量是面临的一个重要问题。本文通过综述以往研究并结合典型地点田间试验结果,从冬小麦种植可减少休闲期土壤蒸发损失、具有的深根系系统可充分利用土壤储水、可利用微咸水替代淡水灌溉、通过限水灌溉发展优质麦生产、冬春形成覆盖层美化和防沙尘效应等方面论述了华北平原种植冬小麦的优势,提出华北平原冬小麦生产需要转变传统高耗水高产量理念,充分发挥冬小麦抗旱、耐盐能力强的特点,在不实施大规模压缩冬小麦种植面积条件下,通过冬小麦限水灌溉和微咸水利用满足对地下水压采需求,充分发挥华北平原冬小麦种植冬春防风沙、美化环境的生态功能,同时满足区域口粮安全的保障功能。     

The nature and management of saprolite aquifers in the wheatbelt of western Australia

Regional weathered-zone goundwaters in the southern part of Western Australia are primarily stored in a granular saprolite aquifer derived from the isovolumetric weathering of granitic and gneissic rocks. Recent drilling has confirmed the existence of permeable materials capable of yielding groundwater of a suitable quality for livestock. Development of supplies of 10 to 250 kl d⁻¹ is realisic and would complement local livestock, domestic and Government water supply systems. Wheatbelt aquifers currently supply 18 to 25 per cent of all water used for livestock in the agricultural areas of the southern part of Western Australia, although less than 1 per cent of the available resource is being utilized. Unused groundwater, artificially recharged by water-use inefficiencies of agricultural development, provides both a potential resource and a cause of soil and water quality deterioration. Groundwater pumping may provide one method of aquifer control to mitigate the influence of secondary salinization. Pumping the low transmissivity Wheatbelt aquifers provides a means to lower water-tables and limit the volume of groundwater reaching saline discharge areas at low points in the landscape. Unlike aquifer pumping systems developed in saline discharge areas, extraction systems in groundwater recharge areas, or in saline areas where groundwaters are of a suitable quality for agricultural use, can be used to mitigate salinity. The volume of groundwater available in southwestern Western Australia usually exceeds livestock requirements, to maintain low water-tables, the water has either to be pumped to suitable drainage systems or alternative uses must be sought.