安徽省阜阳地区深层地下水资源的开发利用

阜阳地区深层水指蕴藏于４０ｍ以深第四第及上第三系的松散岩类孔隙水，下限深度一般３００～９００ｍ属承压水。水位埋深６～２０ｍ，集中开采区２０～４０ｍ。按５０ｍ水位降深估算，天然储量＊约３８．５×１０８ｍ３。深层水以水质优良、储量较大且难以更新为主要特点。其中６６００ｋｍ２范围内蕴藏有高碘地下水，有的已达到国家饮用天然矿泉水标准。６００ｍ以深水温可达３０℃以上，为有待勘查和开发的地热水资源。深层水是目前阜阳地区城镇集中供水的唯一水源。近年来，随着各地竞相抢采深层水的强度逐年加大，合理开发利用深层水资源、保护地质环境，已成为区内水资源开发利用中最突出的问题。开发深层水须以勘查和监测资料为依据，在区域性统一规划可利用总水资源的基础上，实行分质供水、优水优用。要开发高碘地下水和地热水资源，兼顾资源效益。

石河子市区南部地下水异常带成因及其对环境影响

石河子南部低山区基岩裂隙水水质较差,导致该市区南部地下水深埋带水质矿化度偏高。通过对石河子市区40年来地下水动态变化的分析,指出南部高矿化水可能会因过度开采而引发市区水环境的改变,建议增大地表水对市区地下水的补给量,以优化该市水资源配置。

地下水深埋区咸水灌溉对土壤盐渍化影响的初步研究——以民勤绿洲为例

针对民勤绿洲近几十年来大量开采地下水造成地下水位急剧下降,同时大规模开采地下劣质咸水用于农业灌溉的现状,采用咸水沟灌大田试验,就绿洲地下水深埋区(>5 m)咸水灌溉对土壤盐渍化的影响进行了研究。结果表明,在地下水深埋区,灌溉水带入的盐分是土壤表层盐分积累的主要来源;播种前大定额淡水灌溉,土壤明显脱盐,但随着生长季内咸水灌溉及灌溉定额的减少,土壤开始返盐,到生长季末,根区土壤显著积盐,2 g.L-1和5 g.L-1咸水灌溉下土壤的积盐率分别为22.67%和35.30%;高垄覆膜种植方式下,膜上沟灌对沟下土壤盐分淋洗明显,但是在行间非覆膜区盐分强烈聚集;咸水灌溉导致根区土壤pH值升高,碱化度增大,绿洲土壤存在着明显的碱化趋势。

Experimental Study on the Utilization of Shallow Groundwater for Spring Wheat

[Objective]The paper aimed to study effect of shallow groundwater at different depths on crop water requirement and crop evaporation in spring wheat field.[Method]Five treatments of shallow groundwater table at different depth were designed to do evaporation experiment for spring wheat in 2008-2009.[Result]The groundwater at different depths had great impact on crop growth and field evaporation;its supply accounted for 0-52% of actual evapotranspiration.Atmospheric evaporation and crop rooting depth were the major factors to affect the uptake of groundwater at shallow table,and the supply of deep groundwater was controlled by groundwater table.[Conclusion]The study reveled the pattern of evapotranspiration of spring wheat and evaporation of shallow groundwater at different depth,in order to supply basis for the rational and effective utilization of shallow groundwater as well as optimization of the irrigation scheduling for spring wheat.

Subsurface Drainage Impact Assessment-in Ibshan, Egypt

This paper aims to mitigate the impacts of subsurface drainage system in Ibshan, Egypt on the environment. For studying and analyzing these impacts, data are collected concerning before and after the installation of the subsurface drainage system. The environmental impacts are set to be crops yields, salinity, and water table depth. Concerning crops yields, five crops are identified to study the effect of the subsurface drainage system on their productivity. Regarding salinity, the saline areas are investigated pre and post the subsurface drainage system. For the water table depth, the ground water table depths are reviewed before and after the subsurface drainage system. Also, the DRA1NMOD-S computer program is employed to determine the effect of the subsurface drainage system on the water table depth. It is concluded that the environmental impacts of the subsurface drainage system in Ibshan area are very good. The yields of five crops increased from 7% to 38%, 16.4% of saline areas are improved, and the ground water table depth is reduced by 10%. Also, an equation is obtained to predict the percentage decrease of ground water table depth according to the laterals spacing of the subsurface drainage system.

Influence of Flow Regime on the Vegetation Zonation along Mountain Streams in the Western Cape, South Africa

Zonation patterns of riparian vegetation have been sampled and described in mountain streams in two catchments in the Hottentots-Holland Mountains, Western Cape, South Africa. Six main vegetation types that differ in structure and species composition, are dominant along these river banks: Aquatic vegetation, Wetbanks, Palmiet, Scrub, Forest and Shrubland(Fynbos). The study aims to correlate the vegetation patterns to flooding patterns, in particular the inundation frequency and stream power. A problem arises: because these catchments are ungauged, like most mountain catchments, with the only weirs at the downstream end of the catchment. Discharge data at the weirs are extrapolated to the sites upstream by multiplication with a factor based on the size of the subcatchment that drains through a sample site. In this way, recurrence intervals for floods in mountain streams are derived. Discharges at sites are also calculated using bed roughness(Manning's n) and slope in straight sections with uniform flow conditions. Stream power is derived from the discharges calculated in this manner. The combination of stream power and recurrence intervals explains the occurrence of most vegetation types occurring on the banks, except for one type: Afromontane Forest. This type is probably more dependent on other factors, such as protection from fire and the depth of the groundwater table.

CBM geology conditions study of Gemudi syncline,Western Guizhou Province

Through the analysis of the surrounding rock, coal seam burial depth, coal quality and hydrologic geological condition, the methane-bearing property characteristics of the coal reservoir in the Gemudi syncline were elucidated. Most of the wall rock of the coal reservoir is mudstone and silt, which is a favourable enclosing terrane. Burial depth of the main excavating coat seam is moderate. The groundwater activity is thin, and there are absolute groundwater systems between each coal seam, which make poor intercon- nections to accelerate CBM enrichment. In our research, the area coal reservoir meta- morphosis is high, CBM content is high, hole-cranny system development degree is high, and permeability of the great mass of the main coal seam exceeds 0.1×10^-3 μm2, The result demonstrates that the southeast of the Gemudi syncline has the best conditions for prospecting and exploiting CBM.

Soil Characteristics in Selected Landfill Sites in the Babylon Governorate, Iraq

The Babylon Governorate is situated in the middle of Iraq. It covers an area of 5,315 km2 and has 2,092,998 inhabitants distributed throughout its five major cities （Qadhaa）. Presently, there is no landfill site in the governorate that meets the environmental criteria for the disposal of municipal and industrial waste. Consequently, GIS （geographic information system） and methods of multi-criteria decision making were used here to select the best sites in each city in the Babylon Governorate that would fulfil the environmental requirements. Two sites were chosen in each city. As the groundwater is very shallow in this area, the design should ensure against groundwater pollution by leachate from these sites. To avoid this problem, soil investigation was conducted at these sites so that the most suitable landfill design could be accomplished. The results of soil investigation in these sites include the soil profile, groundwater depth, chemical properties, allowable bearing capacity, Atterberg limits test results and material characteristics of the soil strata. From the research, it is believed that the best design is one that puts the landfill above ground.

RS-based research on the relationship between vegetation development and groundwater in upper-middle reaches region of the Yellow River basin

The relationship between the groundwater and the surface eco-environment in arid area is very close. In this paper, the authors extracted normalized difference vegetation index （NDVI） and vegetation conditional ratio （VCR） from MODIS images, and analyzed the relationships among NDVI, VCR and the measured data of groundwater of the same location in the research region. Based on this, the depth of groundwater suitable for vegetation growth in the upper-middle reaches of the Yellow River basin has been calculated. The results show that the depth of groundwater suitable for vegetation growth in the research region ranges from 0.8 to 4.5m, and the optimal groundwater depth is 1.2m. The method developed in this study is applicable to research the relationship between the groundwater and land surface vegetation environment on large-scale in arid area.

Relationship between Water and Vegetation in the Ejina Delta

Water is the foundation of an arid ecological system, as the quantity and quality of surface water and groundwater determine its structure and function. The study on the relationship between water and ecosystem is the basis of ecosystem protection. Taking the Ejina delta, an extremely arid area located downstream of the Heihe River in northwestern China, as an example, this article gives an overviewe of the study in three aspects: (1) the groundwater table and salinity dynamics and their driving factors, (2) the groundwater depth and salt threshold of natural vegetation ecosystem, and (3) the impact evaluation of ecological flow control on Ejina natural vegetation. The authors point out the importance of the research into the relation between water and ecosystem and its key difficulties and weakness, and put forward strategies for promoting the study processes.

Effect of Water Resources Allocation on Groundwater Environment and Soil Salinity Accumulation under Climate Change

The combined surface and groundwater allocation practice by wells and canals had contributed to the safety of groundwater environment and agriculture sustainable production. The typical area in the People＇s Victory Canal irrigation district was taken as a case, drawing together the irrigation district agriculture water consumption and precipitation from 1954 to 2014 in the People＇s Victory Canal irrigation district, ratios of surface to groundwater irrigation amount, dynamic of groundwater depth and hydrochemical characteristic of groundwater from 2008 to 2014 in the research area, the relationship between groundwater depth and ratio of surface to groundwater irrigation amount was analyzed, in order to ascertain the influence of precipitation on ratios of surface to groundwater irrigation amount and its effect on soil and groundwater environment. The results indicated that positive correlation between the ratios of surface to groundwater irrigation amount and annual precipitation was appeared, affected by climate change, average irrigation amount from surface in the recent 5 years was 2.90 x 108 cubic meters, accounted for 75.52% of total irrigation amount, on the other hand, decreasing tendency of precipitation was obvious, and groundwater depth dynamic in upstream of the branch canals was more dramatic than downstream because of surface water irrigation infiltration, under the unified condition of water use efficiency, ratio of surface to groundwater irrigation amount was negative correlation with area of the groundwater depth beyond 11 m, meanwhile, groundwater depth demonstrated negative correlation with the ratio of surface to groundwater irrigation amount, moreover, alkaline trend of groundwater hydrochemistry during the normal season in the research area was obvious because of phreatic evaporation and the agricultural irrigation from wells, along with irrigation from surface inflow of Yellow River, quality of groundwater hydrochemistry during the dry season was ameliorative greatly. Consequently, it was very important to the agriculture sustainable production that well-canal combined irrigation patterns alleviated extremely alkaline trend of the groundwater hydrochemistry and played a positive role of root layer soil salinity leaching.

The effect of hydrologic process changes on NDVI in the desert-oasis ecotone of the Hexi Corridor

In the arid inland river basins of northwestern China,human activities control almost all the surface hydrologic processes.The potential effects of these altered hydrologic processes are gradually becoming clear,especially since the 2000 implementation of the integrated water resources management projects in the Shiyang River,the Heihe River,the Tarim River,and the Shuler River.While the appearance of these eco-hydrology changes and consequent environmental effects in the oasis has attracted broad attention,related research is still lacking.Eco-hydrological process changes in the desert-oasis ecotone were investigated in the Pingchuan irrigation district in the middle reaches of the Heihe River.The results showed that the annual average amount of surface water irrigation during the past 20 years has decreased by 1.498×107 m3,while the annual average amount of well irrigation has increased by 1.457×107 m3,since 2000,when the State Council of China approved the water diversion scheme for the Heihe River Basin.The groundwater depth before the water diversion scheme generally varied between2.44–3.19 m(average 2.73±0.24 m),while that after the water diversion scheme has varied between 3.08–4.01 m(average3.79±0.62 m).The distribution area of<3 m groundwater depth decreased from 3612 to 394 hm2;while the distribution area of>3 m groundwater depth increased from 853 to 3843 hm2.However,although the hydrologic processes changed dramatically,no significant effects on vegetation productivity in the desert-oasis ecotone were detected during the study period.

Water use strategies of the desert riparian forest plant community in the lower reaches of Heihe River Basin, China

The object of this paper is the different plant communities in the Ejina desert riparian forest. Groundwater depth, soil moisture, plant water potential, relative leaf moisture content and water use efficiency was monitored, and the response of soil moisture and plant ecology to the groundwater depth and the water use efficiency of the different plant communities was analyzed. The results showed that：（1） Along with the groundwater depth increasing, predawn and midday water potential of the plants, with the exception of Reaumuria soongorica, did not decrease significantly, indicating that when the groundwater depth is less than 3 m, the plant communities in the range of 4 km from the river way did not suffer or slightly suffer from water stress;（2） The distribution of higher soil moisture content within 0–3 m soil layer is suitable with the plants’ root system, as indicated in the communities of coexisting overripe Populus euphratica or Taramrix chinensis, both of which can release excessive water into soil for shallow rooted shrubs or herbaceous plants when there is water shortage;（3） R. soongorica can absorb deep soil moisture through deep roots for their own survival;（4） The community consisting of Sophora alopecuroides, Karelinia caspica, T. chinensis, and overripe P. euphratica has the best species combination for restoring the damaged eco-environment in the lower reaches of Heihe River;（5） The order of plants’ relative leaf water contents is K. caspica ＆gt; S. alopecuroides ＆gt; young P. euphratica ＆gt; overripe P. euphratica ＆gt; mature P. euphratica = T. chinensis coexisting with other species ＆gt; single R. soongorica ＆gt; single T. chinensis and the order of WUE is single T. chinensis ＆gt; single R. soongorica ＆gt; T. chinensis living in symbiosis with other species ＆gt; S. alopecuroides = young P. euphratica ＆gt; mature P. euphratica ＆gt; overripe P. euphratica ＆gt; K. caspica. Therefore, with ample soil moisture, the plant community helps rapid growth of T. chinensis, young P. euphratica and R. soongorica plants of less moisture content. Despite this they do not have much water storage capability, but have strong drought resistance, and higher moisture contents of S. alopecuroides and K. caspica, thus leaving them with poor drought resistance. Overall, the desert riparian forest plant community in the lower reaches of Heihe River helps the species of higher WUE live on it.

Effect of Groundwater Irrigation on Soil PAHs Pollution Abatement and Soil Microbial Characteristics:A Case Study in Northeast China

To evaluate the effect of groundwater irrigation on the polycyclic aromatic hydrocarbons(PAHs) pollution abatement and soil microbial characteristics,a case study was performed in the Shenfu irrigation area of Shenyang,Northeast China,where the irrigation with petroleum wastewater had lasted for more than fifty years,and then groundwater irrigation instead of wastewater irrigation was applied due to the gradually serious PAHs pollution in soil.Soil chemical properties,including PAHs and nutrients contents,and soil microbial characteristics,including microbial biomass carbon,substrateinduced respiration,microbial quotient(qM),metabolic quotient(qCO2),dehydrogenase(DH),polyphenol oxidase(PO),urease(UR) and cellulase(CE) in surface and subsurface were determined.Total organic C,total N,total P,and available K were significantly different between the sites studied.The PAHs concentrations ranged from 610.9 to 6362.8 μg kg-1 in the surface layers(0-20 cm) and from 404.6 to 4318.5 μg kg-1 in the subsurface layers(20-40 cm).From the principal component analysis,the first principal component was primarily weighed by total PAHs,total organic C,total N,total P and available K,and it was the main factor that influencing the soil microbial characteristics.Among the tested microbial characteristics,DH,PO,UR,CE,qM and qCO2 were more sensitive to the PAHs stress than the others,thus they could serve as useful ecological assessment indicators for soil PAHs pollution.

Spatio-Temporal Variability of Soil Salinity in Alluvial Plain of the Lower Reaches of the Yellow River——A Case Study

Soil salinity and hydrologic datasets were assembled to analyze the spatio-temporal variability of salinization in Fengqiu County, Henan Province, China, in the alluvial plain of the lower reaches of the Yellow River. The saline soil and groundwater depth data of the county in 1981 were obtained to serve as a historical reference. Electrical conductivity （EC） of 293 surface soil samples taken from 2 kin x 2 km grids in 2007 and 4{） soil profiles acquired in 2（108 was analyzed and used for comparative mapping. Ordinary kriging was applied to predict EC at unobserved locations to derive the horizontal and vertical distribution patterns and variation of soil salinity. Groundwater table data from 22 observation wells in 2008 were collected and used as input for regression kriging to predict the maximum groundwater depth of the county in 2008. Changes in the groundwater level of Fengqiu County in 27 years from 1981 to 2008 was calculated. Two quantitative criteria, the mean error or bias （ME） and the mean squared error （MSE）, were computed to assess the estimation accuracy of the kriging predictions. The results demonstrated that the soil salinity in the upper soil layers decreased dramatically and the taxonomically defined saline soils were present only in a few micro-landscapes after 27 years. Presently, the soils with relatively elevated salt content were mainly distributed in depressions along the Yellow River bed. The reduction in surface soil salinity corresponded to the locations with deepened maximum groundwater depth. It could be concluded that groundwater table recession allowed water to move deeper into the soil profile, transporting salts with it, and thus played an important role in reducing soil salinity in this region. Accumulation of salts in the soil profiles at various depths below the surface indicated that secondary soil salinization would occur when the groundwater was not controlled at a safe depth.

Prediction of water table depths under soil water-groundwater interaction and stream water conveyance

Water table over an arid region can be elevated to a critical level to sustain terrestrial ecosystem along the natural channel by the stream water conveyance. Estimation of water table depth and soil moisture on river channel profile may be reduced to a two-dimensional moving boundary problem with soil water-groundwater interaction. The two-dimensional soil water flow with stream water transferred is divided into an unsaturated vertical soil water flow and a horizontal groundwater flow. Therefore, a prediction model scheme for water table depths under the interaction between soil water and groundwater with stream water transferred is presented, which includes a vertical soil water movement model, a horizontal groundwater movement model, and an interface model. The synthetic experiments are conducted to test the sensitivities of the river elevation, horizontal conductivity, and surface flux, and the results from the experiments show the robustness of the proposed scheme under different conditions. The groundwater horizontal conductivity of the proposed scheme is also calibrated by SCE-UA method and validated by data collected at the Yingsu section in the lower reaches of the Tarim River, which shows that the model can reasonably simulate the water table depths.