基于页岩气开发的威远县水环境承载力评价

为了科学合理评价分析威远县页岩气开发区水环境承载力,从社会资源、水资源、水环境三方面构建指标体系,通过模糊综合评价法构建基于页岩气开发的水环境承载力评价体系,并对威远县水环境承载力进行计算和评价。计算结果表明：2009～2018年间威远县页岩气开发水环境承载力评分值在0.246 6～0.764 0范围内,整体呈上升趋势,从临界承载状态上升为适宜承载状态；各子系统之间的评分值差异较大,水资源子系统评分值整体处于下降趋势,研究期内平均评分值达0.622 2,总体评分值较高,社会经济子系统和水环境子系统评分值呈上升趋势,两者为水环境承载力的提升奠定了基础；人口密度过大,水资源开发利用率过高、年均用水总量较高,人均水资源量较少,压裂液返排率较低成为制约威远县页岩气开发水环境承载力的关键因素。可见对威远县页岩气开发水环境承载力的评价针对性强,可以更为有效的为提高威远县水环境承载力提出针对性的优化和建议。

Evaluation of water environmental carrying capacity in Weiyuan County based on shale gas development

In order to scientifically and rationally evaluate and analyze the water environmental carrying capacity of Weiyuan Shale gas development zone, an index system was constructed from three aspects of social resources, water resources and water environment, and an evaluation system of water environmental carrying capacity based on shale gas development was constructed through fuzzy comprehensive evaluation method, and the water environmental carrying capacity of Weiyuan County was calculated and evaluated.The results show that: From 2009 to 2018, the water environmental bearing capacity score of Shale gas development in Weiyuan County is within the range of 0.2466-0.7640, showing an overall upward trend, rising from the critical bearing state to the appropriate bearing state;There was a large difference in the score values among the subsystems, and the overall score value of the water resources subsystem was in a downward trend. The average score value reached 0.6222 during the study period, indicating a high overall score value. The score values of the socio-economic subsystem and the water environment subsystem showed an upward trend, which laid a foundation for the improvement of the water environment carrying capacity.Large population density, high utilization rate of water resources development, high annual total water consumption, less water resources per capita, low fracking fluid backflow rate have become the key factors restricting the water environmental carrying capacity of shale gas development in Weiyuan County.It can be seen that the evaluation of water environmental carrying capacity of shale gas development in Weiyuan County is highly targeted, which can put forward targeted optimization and suggestions for improving water environmental carrying capacity in Weiyuan County more effectively.