基于多约束条件下六股河地段地下水优化开采方案研究

1、基于多约束条件下六股河地段地下水优化开采方案研究        【中文摘要】六股河地段位于葫芦岛市的西南部,属典型的滨海河谷区。该区地下水资源开发利用程度较高,随着人口增长和社会经济的发展,研究区对水资源需求量也随之增长,同时污水排放量不断增加、沿海地带由于地下水的大量开采引起海水进侵导致地下水水质流域生态环境的恶化,上述现象已经成为制约绥中六股河地区经济发展的主要影响因素。因此,如何使地下水资源量满足研究区经济发展的需求,又不致使流域生态环境恶化,成为很亟待解决的题目。本文以六股河地段已有地质、水文地质资料为基础

2、,利用Visual Modflow对研究区地下水流进行数值模拟,讨论了水位、水质、水量、生态环境等约束条件的内涵及作用,并结合以上约束条件确定了拟建水源地的优化开采布局,在优化开采布局基础上进而确定地下水优化开采方案,对六股河地段地下水未来开采规划和类似条件下的研究具有理论和实际的双重意义。');【Abstract】 With the development of economy, the water demand of the industry has increased year by year, the volume of water supply can not meet de

3、mand, water supply and demand contradictions have become increasingly prominent. Liu gu river section locates at south-west of Huludao City, under the jurisdiction of Huludao City, with an area of 378.78 km2, the industrial and agricultural water of this area are mostly from alluvial aquifer, develo

4、pment and utilization level of groundwater level has been very high, therefore, whether the pumping layout and project optimal or not has great influence to the economic and social development of Suizhong and Huludao City.The topography of Liu gu river section is higher in the north and lower in the

5、 south and terrain is flat open, tilts to the sea slightly, elevation generally is less than 20 m .There is abundant groundwater in the Quaternary layer, which is revealed along the river valley and piedmont. The general characteristics of the aquifer are thin, buried shallow, adequate and easy expl

6、oiting. Because bedrock is widely distributed around the study area and groundwater isnt abundant and little significance, Therefore, the alluvial and coastal plain are chosen as the simulation area. The main mining aquifer of study area consists of three parts: the first is the upper Holocene Sedim

7、ents aquifer, with a thickness of around 20 m; the second is upper pleistocene aquifer, which thickness is 14 to 22 m; the third is middle Pleistocene aquifer, which thickness is 3 to 8 m; these three above aquifers compose unconfined aquifer which is the purpose aquifer of this study. Based on the

8、Liu gu river sections datum including weather, su*ce runoff, geology, hydrogeology and groundwater exploitation, the thesis analyses the configurable characters of purpose aquifers and the recharge, runoff, discharge and dynamic characters of groundwater. On the foundation, the hydrogeological model

9、 has been established, and the study area is generalized as heterogeneous isotropic two-dimensional unsteady flow of phreatic water, then the math equation has been established, which is solved using Visual MODFLOW software. In the following, the established model needs to be identified and validate

10、d by the water lever datum The results indicate: the established model fits to the precision demand, and is comparatively right, so it can be used to forecast the coming water level.With the actual situation of the study area, optimal mining project of a variety of constraint conditions (including w

11、ater level constraints, water volume constraints, the water quality constraints, environmental and ecological constraints, etc.) conduct in-depth analysis, and specified the content an functions of all constraints, On this basis, this *s designs different groundwater mining layout, and simulate grou

12、ndwater flow and water level changes by the groundwater numerical model at the conditions of different layout of the same exploitation of the total extraction, then determine the west bank of Liu gu river and Da Shibao-Tashan layout as two optimal water exploiting distribution, and by comparing grou

13、ndwater flow field of two layouts for decades mining, the results show that have to building underground dams to prevent seawater intrusion.On the basis of the determined optimal exploitation layout, the thesis designs different exploiting distribution projects and mining time according to different

14、 precipitation guarantee rate. Then Simulated the project of the mining operations under the certain exploitation and meeting all the constraints conditions, analysis the simulation results and determined the groundwater optimization project of Liu gu River section based on the multiple-restrictive

15、conditions. In term of current pumping project, according to water resource requirement of social economy, the groundwater resources is evaluated in the following 10 years. The results show that the study area is in the state of negative balance on the whole, from the view of the total volume of gro

16、undwater resources, groundwater recharge guarantee rate was 100.6% in normal years, groundwater resources apart from meeting excretion, there is still residual, and the remaining amount of 243.13×104m3 / a, compensation can be used in the dry storage of -235.08×104m3 / a, groundwater resou

17、rces to be dynamic equilibrium after regulating in the Feng ku period. From the view of groundwater flow field map: from November to April next year in wet andpeace years, the ground water level larger declined around the DaShibao - Tashan, local areas even landed cone of Groundwater Depression, who

18、se centre the water level was 2.06 m, which is meeting designed constraints, in the wet period, even if to intensify the exploitation of the west bank of Liu gu River, the biggest drawdown is 6.62 m, which accounts for 16% of the aquifer thickness, also meets the water constraints; In the 75 per cent of the guaranteed rate, at the end of the dry season, the water level of cone depression is -1.04 m, account the aq