延吉市地下水资源评价及可持续利用研究

发布时间：2018-05-01 03:39

本文选题：延吉市 + 地下水资源　；参考：《吉林大学》2014年硕士论文

【摘要】：随着城市发展及人民生活水平的提升，对于水资源的需求量也在增大，地下水在水资源开发利用中的地位也在不断提升，地下水资源的可持续利用已成为城市发展的重要保障。延吉市的主要供水水源地为五道水库及延河水库，但由于城市发展需水量的增大，以及地表水库本身的限制性，地下水成为了城市供水的重要补充资源。因此，开展延吉市地下水资源的评价及可持续利用研究对于延吉市城市发展具有十分重要的意义。本次研究区的范围为延吉市城市规划区，涵盖了整个延吉盆地，面积约为87.81km2，该区域包括了布尔哈通河在延吉市境内的大部分流域。本次评价的目标含水层为第四系松散岩类孔隙水和白垩系碎屑岩类孔隙裂隙水。白垩系碎屑岩类孔隙裂隙水为承压含水层，第四系松散岩类孔隙水为潜水含水层，两含水层之间为由白垩系龙井组上部的粉砂岩、泥岩组成的隔水层。松散岩类孔隙水处于地下水流动系统的排泄区，其主要的补给来源为大气降水入渗补给及侧向径流补给，排泄的主要方式为蒸发、径流、泄流及人工开采；碎屑岩类孔隙裂隙层间承压水主要的补给来源为越流补给和侧向径流补给，排泄的主要方式为径流排泄、泉及人工开采。根据“延龙图地区环境地质调查评价”2012年度延吉市水文地质调查结果，结合相应的气象水文等资料，对研究区进行地下水均衡计算：2012年度地下水总补给量为1001.38×104m3/a，总排泄量为844.81×104m3/a，地下水呈现正均衡；根据水均衡计算得到研究区的允许开采量为547.48×104m3/a。利用Visual MODFLOW建立了地下水数值模型，通过识别和验证，水位拟合误差小于1m的结点分别占已知水位结点的92.7%和87.03%，，水位拟合情况良好，可以利用该模型进行地下水动态的模拟与预报。针对延吉市城市供水现状及未来供水需求，利用地下水数值模型对研究区在不同开采条件下的地下水水位进行了模拟预报，结果表明：目前开采布局较为不合理，在多年平均降水条件下，现状开采量大于允许开采量，地下水处于超采状态；按照城市未来供水需求以每年3％的增量进行地下水开采的条件下，地下水水位表现出明显持续下降的趋势，不能保障地下水资源的可持续利用；采用较为合理的开采布局，以模拟期内潜水水位下降不超过含水层厚度的1/3，承压水水位不超过含水层顶板为控制原则，得到地下水允许开采量为446.67×104m3/a；在城市地表水供水系统遇到突发情况下，以地下水开采量满足目前城市正常供水的条件下，可保障持续供水约165天；按照城市供水需求的增加，2020年地下水资源在应急条件下可保障持续供水约95天，2030年地下水资源在应急条件下可保障持续供水约90天。
[Abstract]:With the development of cities and the improvement of people's living standards, the demand for water resources is also increasing, and the status of groundwater in the development and utilization of water resources is also increasing. The sustainable utilization of groundwater resources has become an important guarantee of urban development. The main sources of water supply in Yanji are Wudao Reservoir and Yanhe Reservoir. However, due to the increase of urban water demand and the restriction of surface reservoir itself, groundwater has become an important supplementary resource for urban water supply. Therefore, it is very important for Yanji city to develop the evaluation and sustainable utilization of groundwater resources in Yanji city. The scope of the study area is Yanji city planning area, covering the whole Yanji basin, the area is about 87.81km2, this area includes most of the river basin in Yanji city. The target aquifer is Quaternary loose rock pore water and Cretaceous clastic rock pore fissure water. The pore fissure water of clastic rocks of Cretaceous is confined aquifer, pore water of Quaternary loose rock is phreatic aquifer, between the two aquifers is siltstone in the upper part of Longjing formation of Cretaceous, and the water-isolating layer is composed of mudstone. The porous water of loose rock is in the discharge area of groundwater flow system, the main recharge source is precipitation infiltration recharge and lateral runoff recharge, the main way of discharge is evaporation, runoff, discharge and artificial mining. The main recharge sources of the confined water between pore and fissure layers of clastic rocks are overflowing recharge and lateral runoff recharge, and the main ways of discharge are runoff discharge, spring water and artificial mining. According to the results of the environmental geological survey and evaluation of Yanji City in 2012, combined with the corresponding meteorological and hydrological data, The total groundwater recharge is 1001.38 脳 10 4 m 3 / a, the total discharge is 844.81 脳 10 4 m 3 / a, and the groundwater is in positive equilibrium, according to the calculation of water equilibrium, the allowable exploitation of the study area is 547.48 脳 10 4 m 3 / a, and the total groundwater recharge is 1001.38 脳 10 4 m 3 / a and the total discharge is 844.81 脳 10 4 m 3 / a. The numerical model of groundwater is established by using Visual MODFLOW. The results of identification and verification show that the nodes with water level fitting error less than 1m account for 92.7% and 87.03% of the known water level nodes, respectively, and the water level fitting condition is good. The model can be used to simulate and forecast groundwater dynamics. In view of the present situation of urban water supply and the future water supply demand in Yanji City, the groundwater level in the study area under different mining conditions is simulated and forecasted by using the groundwater numerical model. The results show that the current mining layout is unreasonable. Under the condition of annual average precipitation, the current exploitation amount is larger than the allowable amount, and the groundwater is in a state of overexploitation. In accordance with the future urban water supply demand, the groundwater is exploited in an increment of 3% per year. The groundwater level shows an obvious trend of continuous decline and cannot guarantee the sustainable utilization of groundwater resources. Based on the control principle that the groundwater level drops less than 1 / 3 of the aquifer thickness and the confined water level does not exceed the roof of the aquifer during the simulation period, the allowable groundwater exploitation rate is 446.67 脳 10 4 m3 / a. In the case of a sudden situation in the urban surface water supply system, If the groundwater exploitation can satisfy the condition of the normal water supply in the city at present, the sustainable water supply can be guaranteed for about 165 days. According to the increasing demand for urban water supply, groundwater resources can guarantee continuous water supply for about 95 days under emergency conditions in 2020 and 90 days under emergency conditions in 2030.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：P641.8

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