煤矿临时建设用地复垦适宜性评价——以重庆綦江区为例

Reclamation Suitability Evaluation of the Temporary Construction Land of Coal Mines——A Case Study of Qijiang District,Chongqing Municipality

开展煤矿临时建设用地复垦是矿区生态恢复、补充耕地、实现节约集约用地目标的重要途径之一.以重庆綦江区存在临时性建设用地的14个煤矿为研究背景,从煤矿临时建设用地复垦的适宜性、驱动力和约束力3个维度出发,构建由自然因素、区位因素、人口因素等8个因素,坡度、土地破坏程度、土源保证率等20多个评价因子组成的煤矿临时建设用地复垦适宜性评价指标体系,并采用综合权重法(AHP层次分析法+熵权法)进行指标赋权,从地块尺度出发,确定复垦方向.结果表明:(1)适宜复垦为生态用地的煤矿临时建设用地,占总面积的57.67%,主要为坡度较大、岩土污染较重、周边地类为林草地且距离林草地较近的地块;(2)适宜复垦为农业用地的煤矿临时建设用地,占总面积的39.25%,这些地块离村庄较近,土源保证率较高,灌排条件较好;(3)适宜续用为建设用地的煤矿临时建设用地,仅占总面积的3.07%,主要为一些地面建筑保存较好,旧物利用率较高的地块.该研究将复垦过程中的环境影响要素及复垦的隐形风险纳入评价体系中,对科学合理的开展煤矿临时建设用地复垦进行了有益探索.

Reclamation of temporary construction land in mine areas is an important approach to ecological restoration of mines,supplementation of cultivated land and realization of the goal of saving and intensive use of land.Taking 14 coal mines,which have temporary construction land,in Qijiang district of Chongqing as the research background and starting from three dimensions of temporary construction of land reclamation：suitability,driving force and binding force,this paper builds a suitable evaluation index system of reclamation in temporary construction land,which is made up of 8 factors such as nature,location and population,and more than 20 evaluation factors,including slope,degree of land damage,and land supply guarantee rate.A comprehensive weighting method（AHP＋ TOPSIS）is adopted to carry out the index weighting,thus to determine the direction of reclamation from the plot scale.The temporary construction land of coal mines which is suitable for reclamation as ecological land is shown to account for 57.67% of the total.It consists mainly of plots with large slopes and heavy soil and rock pollution which are close to forest and grass lands.The temporary construction land of coal mines which is suitable for agricultural land accounts for 39.25% of the total.These plots are mostly situated closely to villages and have a relatively high land supply guarantee rate and satisfactory irrigation and drainage conditions.Only 3.07% of the total area of temporary construction land of coal mines is suitable for construction land.The buildings on such plots are usually maintained in fairly good condition and the utilization rate of the old buildings is high.In this study,the environmental impact factors and the invisible risks in the reclamation process are included in the appraisal system,which should be helpful for the scientific and rational development of reclamation of temporary construction land.