拉萨市河谷平原区地下水资源评价与合理开发利用

发布时间：2018-11-11 20:18

【摘要】：拉萨市河谷平原区是西藏自治区人口最密集、经济发展最快的地区之一,属高原河谷地貌,水文地质工作程度较低,地下水开采量大,缺乏系统的地下水资源评价研究。本文对拉萨市河谷平原区地下水资源进行评价和分析,旨在为该地区地下水资源的合理开发利用提供科学依据。本文在系统分析研究区地质和水文地质条件的基础上,建立了拉萨市河谷平原区水文地质概念模型,并基于GMS软件建立地下水流数值模型,并对模型进行了识别和验证,结果良好。利用水均衡法和数值法进行了地下水水均衡计算分析对比,得到地下水可开采量分别为345222.21m3/d、303687.40m3/d,地下水开采潜力指数分别为0.96和0.97,均处采补平衡状态,对比可知计算结果是合理的;地下水水质综合评价结果表明,研究区地下水水质整体上优良,部分地区水质较差。拉萨市河谷平原区地下水动态变化主要表现为地下水位的整体下降,并表现出一定的阶段性,但地下水流场整体趋势没有发生变化。利用地下水流数值模型,进行1970年、2000年以及2015年地下水均衡计算分析,结果对比表明:地下水均衡逐渐由正均衡变为负均衡,拉萨河在水均衡中起了至关重要的作用;人类活动对地下水产生影响的原因主要有地下水开采量逐年增加、城市建设用地不断增加以及湿地面积的减小。应用建立的地下水流模型,预报了不同开采方案的水位变化情况,表明:在现状开采布局条件对地下水位影响较小,但开采量增加不应超过现状的二分之一;在增加开采量的情况下,沿拉萨河新增水源地分担开采量为最佳开采方案。综合分析后,为拉萨市河谷平原区地下水资源合理开发利用提出了措施。
[Abstract]:The valley plain of Lhasa is one of the most densely populated areas with the fastest economic development in Tibet Autonomous region. It belongs to the valley landform of the plateau. The degree of hydrogeological work is low, the exploitation of groundwater is large, and there is a lack of systematic evaluation of groundwater resources. In this paper, the groundwater resources in the plain area of the valley of Lhasa City are evaluated and analyzed in order to provide scientific basis for the rational development and utilization of the groundwater resources in this area. Based on the systematic analysis of the geological and hydrogeological conditions in the study area, the conceptual model of hydrogeology in the plain area of Lhasa valley is established, and the numerical model of groundwater flow is established based on GMS software, and the model is identified and verified. The result is good. The groundwater equilibrium was calculated and compared with the numerical method. The recoverable groundwater was obtained as 345222.21m3 / d 303687.40m3 / d, and the groundwater exploitation potential index was 0.96 and 0.97, respectively. The equilibrium state of complement is adopted at the same place, and the comparison shows that the calculation result is reasonable. The results of comprehensive evaluation of groundwater quality show that the groundwater quality in the study area is good on the whole and poor in some areas. The dynamic change of groundwater in the plain area of Lhasa river valley mainly shows that the groundwater level decreases as a whole and shows certain stages, but the overall trend of groundwater flow field does not change. By using the numerical model of groundwater flow, the groundwater equilibrium was calculated and analyzed in 1970, 2000 and 2015. The results showed that the groundwater equilibrium gradually changed from positive equilibrium to negative equilibrium, and the Lhasa River played an important role in the water balance. The main reasons for the influence of human activities on groundwater are the increase of groundwater exploitation year by year, the increasing of urban construction land and the decrease of wetland area. By using the groundwater flow model established, the variation of water level of different mining schemes is predicted. The results show that the present mining layout condition has little influence on the groundwater level, but the increase of mining yield should not exceed 1/2 of the present situation; Under the condition of increasing mining capacity, the optimum mining plan is to share the new water source along Lhasa River. After comprehensive analysis, the measures are put forward for the rational development and utilization of groundwater resources in the plain area of Lhasa valley.
【学位授予单位】：山东科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P641.8

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