山地页岩气开发的生态环境风险定量表征方法研究

The southwest mountainous areas is the main shale gas producing areas in China. Considering the specific geographical conditions of the mountainous areas, researching on eco-environmental risk assessment method for shale gas development is very significant to effectively identify ecological risks, and accurately control ecological risks of shale gas development in the mountainous areas. The potential resource shortage, environmental pollution, landscape destruction, habitat degradation and other ecological environmental problems of the whole process of shale gas development in the mountainous areas are analyzed. The eco-environmental risks of shale gas development are identified, and the exposure and response relationship between risk sources and risk receptors is revealed. The risk dominant factor is determined, and the method of quantitative characterization of mountainous shale gas development in watershed scale is constructed basing on the risk probability theory. Taking the typical mountainous area(Chongqing) as an example, selecting three periods of shale gas development, basing on hydrological analysis model, spatial accessibility analysis and statistical analysis model, relevant spatial data obtained. Combined with the environmental monitoring data, the quantitative evaluation of ecological environmental risk of shale gas development in Chongqing is accomplished. In this way, the feasibility, applicability and effectiveness of the method of the shale gas development eco-environmental risk quantitative assessment is verified.It provides scientific basis for the prevention of ecological environment risk of mountain shale gas development, and provides some reference and technical support for the eco-environmental risk assessment of mountain shale gas development.

我国页岩气的主产区主要集中于西南山地,针对山地特殊的地理条件,面向页岩气开发过程的生态环境风险定量评估方法研究,对有效识别生态环境风险,准确地进行山地页岩气开发的生态环境风险空间防范具有重要意义。本项目面向页岩气开发全过程,分析潜在资源短缺、环境污染、景观破坏、生境退化等生态环境问题,识别山地页岩气开发的生态环境风险,揭示风险源-受体的暴露响应机理;确定风险主导因子,基于风险概率理论,构建流域尺度的山地页岩气开发生态环境定量表征方法;以典型山地重庆为例,选取页岩气开发3个时段,基于水文分析模型、空间可达性分析及地统计分析模型等计算评价指标,运用所构建的页岩气开发生态环境定量表征方法,实现重庆市页岩气开发的生态环境风险定量评价,以此实证方法的可行性、适用性和有效性。为山地页岩气开发的生态环境风险空间防范提供科学依据，为山地页岩气开发的生态环境风险评价提供一定参考及技术支持。

我国页岩气的主产区主要集中于西南山地,山地特殊的地理条件,页岩气开发对区域生态环境带来潜在风险。项目面向页岩气开发全过程,识别了潜在水资源短缺、水环境污染、景观破坏、生境退化等关键生态环境风险,揭示了风险源-受体的暴露响应机理;基于风险概率理论,构建了流域尺度的山地页岩气开发生态环境定量表征方法;以典型山地重庆为例,选取页岩气开发2010-2020年段,基于水文分析模型、空间可达性分析及地统计分析模型等计算评价指标,实现了重庆市页岩气开发的生态环境风险定量评价,实证了方法的可行性、适用性和有效性。结果表明：1）山地页岩气开发的水资源短缺风险含资源型、季节性、工程型三种缺水类型。2015-2020年重庆页岩气开发水资源占用率为0.03-0.05%，水资源短缺风险总体不大，低风险占50%以上。渝西资源型缺水地区，及渝东南、渝东北季节性、工程性缺水局部地区，页岩气开发水资源短缺风险较大。2）污染源到水体的路径是影响山地页岩气开发水环境污染风险的重要因素。重庆境内页岩气开发水环境污染中等及高风险区低于10%。2010-2020年，渝西局部污染负荷有所增加，页岩气开发的污染贡献率0.32~11.5%。3）不同地下水类型，其固有脆弱性表征差异较大，土地利用类型、土壤类型、岩性和地下水埋深是地下水固有脆弱性的重要影响因子。4）生态风险因果链模型能够反映页岩气开发地表扰动带来的生境破坏、土地退化等生态风险。2010-2020年，重庆页岩气开发土地损毁带来的生态风险有所增加，中、高生态风险区占市域面积的40%以上，渝东南生态风险增加明显。研究确定了山地面向页岩气开发过程的生态环境风险主导因子及定量表征模型，明晰了山地页岩气开发生态环境风险的形成机理。为山地页岩气开发的生态环境风险空间防范提供科学依据，为山地页岩气开发的生态环境风险评价提供一定参考及技术支持。