新疆石河子地区地下水硝酸盐含量分布及影响因素分析

为了初步掌握石河子地区平原区地下水硝酸盐污染状况,通过调查取样分析,对研究区地下水硝酸盐含量状况及其影响因素进行了研究。结果表明,石河子地区地下水硝酸盐含量普遍较低,仅有3.03%的取样点超过《生活饮用水卫生标准(GB5749-2006)》。研究区内地下水硝酸盐氮含量空间分布特征显著,水平分布特征表现为从南到北逐渐降低,垂向分布特征表现为潜水区硝酸盐氮含量高于承压水区。影响地下水硝酸盐氮含量的主要因素包括含水层特性、地下水氧化还原条件、降水量等自然因素以及氮肥施用量、种植制度和农业污染源等人为因素。该研究对石河子地区饮水安全和地下水保护有现实意义。     

大规模开采条件下我国北方区域地下水水化学变化特征

本文在总结近些年来我国北方地下水水文地质调查成果的基础上,对大规模开采条件下我国北方主要盆地和平原地下水化学变化规律及其影响因素进行探讨。结果表明:在大规模开采地下水后,我国北方地下水水化学变化特征主要表现为:浅层地下水水化学类型向重碳酸型水转变,地下水硬度增高,且在地下水大规模开发利用时间比较早的山西盆地、华北平原和东北平原变化比较明显,在西北干旱地区并不明显;深层地下水水化学类型由重碳酸型水转变为其它类型,地下水矿化度增大,水质变差,且在新疆准噶尔盆地、山西盆地和华北平原及东北平原变化比较明显。同时在地下水强烈开采区的潜水和承压含水层及主要城市区的地下水水化学特征均表现为常量组分升高,矿化度增大,污染组分和污染程度增加。导致这些变化产生的原因主要是70年代以后地下水的大规模开发利用引起地下水流场发生变化和局部地区人类活动影响造成的污染物增加和不合理排放。     

电力工程地下水环境影响评价方法研究

文章根据从事电力工程地下水环境影响评价的方法,介绍了电力工程地下水评价,探讨了电力工程地下水评价等级的评价,分析了前电力工程地下水环境影响评价实践中存在的技术问题,对地下水评价过程中的评价等级划分、项目所在区地质环境现状调查、水文地质试验及参数计算、地下水污染源确定及影响预测、污染防治措施的确定等方面构建出电力工程地下水环境影响评价的整体框架,提出了地下水环境影响评价的整体思路,并以完成审批的电力工程为例进行了分析和探讨.     

北方典型设施蔬菜种植区地下水水质特征

为探究设施农业对地下水环境质量的影响,以我国华北平原典型设施蔬菜种植区为研究对象,采用常规理化分析、紫外-可见吸收光谱及荧光光谱技术,结合平行因子分析、主成分分析和二维相关光谱分析方法,对种植区地下水中无机盐、重金属及有机物的来源、组成、赋存分布及可能成因进行了研究.结果表明,设施蔬菜种植区地下水水化学特征为Cl-SO_4型水,硬度高,三氮含量严重超出国家地下水V类质量标准(GB/T 14848-93),重金属含量低于国家生活饮用水卫生标准(GB 5749-2006).氮素中NH_4~+-N的大量累积与较浅的地下水埋深度和强还原环境引起的硝化过程受阻有关,部分有毒亲硫重金属元素含量较高为农药和化肥的施用所致.地下水中溶解性有机物来源相似,由微生物代谢淋溶进入地下水的有机粪肥中组分新近产生为主,其主要成分为小分子易降解的类蛋白物质,同时含有部分与类蛋白物质结合的类富里酸物质.种植区地下水中类富里酸物质在地下水中含量稳定,而类蛋白物质含量受耕作过程有机粪肥的使用影响较大.设施蔬菜种植过程中应科学分配有机粪肥的施用,同时水质电导率、硬度及紫外区UVA波段应作为该种植区日后在线监管的主要指标.     

台南温泉井流量异常与南黄海地震关系初析

江苏省东台市台南温泉井１３年来共有三个时段的流量有较大幅度的异常都对应了南黄海一平方度内发生的４次４６～６３级地震。本文对该井的地质构造条件、观测方法、震前异常特征、干扰因素的排除、映震效能、异常机理、流量异常与地震三要素的关系等作了介绍和讨论。     

乌蒙山重点地区地下水水化学特征及成因分析

乌蒙山区是中国西南贫困连片分布区,水资源短缺问题已成为制约当地生态环境建设和社会经济发展的重要因素。本文选取乌蒙山重点地区赫章县和纳雍县作为研究区,采用描述性统计、Piper三线图、相关性分析和离子比例系数法对地下水化学特征及成因进行了分析。结果表明:(1)Ca~(2+)和Mg~(2+)为地下水中主要阳离子,HCO-3和SO2-4为地下水中主要阴离子,微量元素检出率较高,部分含量超标。HCO3·SO4-Ca型、HCO3-Ca型、HCO3·SO4-Ca·Mg型为主要地下水水化学类型;(2)碳酸盐的溶解作用和硫化物的氧化作用是地下水中两种主要的水文地球化学过程,共同决定了地下水的离子构成和水化学类型,部分地区还存在石膏和岩盐的溶解,人类活动对地下水也有一定的影响。     

Response of three dominant shrubs to soil water and groundwater along the oasis-desert ecotone in Northwest China

The ecotone from oasis to desert is an important area for combating sandy desertification. Three dominant desert shrubs (Nitraria tangutorum, Calligonuum mongolicum, Haloxylon ammodendrori) were selected in Minqin Oasis, Northwest China, to determine the groundwater level; soil water potential; and change of the three shrubs in density, coverage, and biomass along the natural and seminatural oasis-desert ecotone (ODE), respectively. The results indicated that traits of desert plant interaction with the topsoil water and groundwater depth along the ODE play an important role in generating complex desert vegetation spatial dynamics. Some natural desert plant species with shallow root systems will distribute themselves according to distribution of topsoil water. Thus, the distribution of Nitraria tangutorum had a decreasing trend in distribution along ODE. Calligonuum mongolicum occurs in different trends in natural and seminatural ODE due to utilizing groundwater as well as topsoil water. Some plant species with deep roots, such as Haloxylon ammodendron, will show more degradation near oases and will exhibit an ascending trend along ODE. Therefore, it is of primary importance to protect the integrity of groundwater depth in order to protect the stability of the oasis-desert ecotones. The text was submitted by the authors in English.     

九江市地下水易污性评价——基于DPASTIC指标的模糊综合评价模型

从污染物入渗土壤-包气带-含水层的过程出发，以地质、地貌、水文地质条件为主控因素，选取地下水埋深〖WTBX〗(D)、降雨入渗补给量(P)、含水层岩性(A)、土壤类型(S)、地形坡度(T)、非饱和带介质(I)及含水层渗透系数(C)〖WTBZ〗7个指标，建立了九江市地下水易污性评价DPASTIC指标体系。结合模糊数学理论和方法，建立了基于DPASTIC指标的模糊综合评价模型。该模型克服了指标参数级别划分定额差异和指标值不连续性变化的缺陷，寻求出最优的级别定额划分状态和指标值的连续性变化情况；在指标级别定额划分上，引用了指标标准特征值的概念，根据实测参数数据资料，建立了10个级别的指标标准特征值矩阵，确定指标参数的最优相对隶属度。结合MAPGIS软件得出最后的地下水易污性分区，评价结果与规划区的实测及预测的水环境质量相吻合。     

AN EFFICIENT RESPONSE MATRIX METHOD FOR COUPLING A GROUNDWATER SIMULATOR AND A REGIONAL AGRICULTURAL MANAGEMENT MODEL1

ABSTRACT: By extending the concept of response matrix to consider “active” and “passive” effects, an efficient response matrix method is developed for coupling a groundwater simulator and a regional agricultural management model The method eliminates the need to store all of the recovery information from preceding time periods. Active effects are those which occur during the actual application of a pumping or recharge stress while passive effects represent the recovery of water levels from an initial departure from steady-state conditions at the beginning of a time step. Derivation of the required matrices and a numerical example are presented for the Salinas Valley groundwater basin in California.     

WATER TABLE INDUCED SHRUB-HERBACEOUS ECOTONE: HYDROLOGIC MANAGEMENT IMPLICATIONS1

ABSTRACT: Environmental factors were investigated across a shrub-herbaceous ecotone (sharp zone of change) on a sloping site underlain by shallow groundwater on the arid floor of Owens Valley, California. Dominant plant species were salt rabbitbrush (Chrysothamnus nauseosus ssp. consimilis [E. Greene] Hall and Clements) and saltgrass (Distichlis spicata var. stricta EL.] E. Greene); typical of many similar habitats across the Great Basin. Historic air photographs were analyzed, and soil properties, water table levels and shrub and herbaceous cover were measured at discrete sample points. To investigate soil and vegetation spatial properties, sample points were apportioned on both sides of the ecotone. Land management practices and fire were ruled out as causal factors for the ecotone which remained stable through a 45-year period of air photo record. Soil textural, chemical and hydraulic properties were similar across the ecotone and were uniform throughout the site. Only depth to the water table changed significantly in a gradient perpendicular to the ecotone. The shrub-herbaceous ecotone was located where the water table depth fluctuated periodically between 0.8 and 1.2 m; deeper water tables than this range favors shrub cover while shallower depths favors meadow vegetation. When extrapolated to hydrologic management such as groundwater pumping, such a shallow depth and a narrow range of amplitude could restrict options for water development if maintenance of meadow vegetation is a goal.