Ecological Risk Assessment of the Yulin Coal Mining Area Based on the PETAR Method
基于生态梯度风险评价方法的榆林煤炭开采区生态风险评价

In order to unravel the correlation and causality between multi-stressor sources, multi-risk receptors, and multi-type ecological effects of the Yulin Coal Mining Area, five members of the project team conducted social surveys in April, 2008 and October, 2009. Through qualitative evaluation, this study preliminarily described the main stressor sources, risk receptors, and the largest ecological effect over the Yulin coal mining area and progressive and conductive relation among the stressor sources, risk receptors, and ecological effects using the Procedure for Ecological Tiered Assessment of Risk method (PETAR). It was found that coal production processes of the coal mining industry was the main risk source; land, vegetation, water resources, and the atmosphere are major risk receptors. The ground collapse, trap mine drainage, soil pollution, vegetation wither, water pollution and water capacity loss, and air pollution were possible ecological effects caused by stressor sources. By means of the semi-quantitative evaluation and introducing fuzzy comprehensive evaluation method, some evaluation on the largest ecological effects caused by stressor sources to risk receptors was performed. It was found that Shenmu County was the sub-region which may suffer from the risk sources. Evaluation of six specific sub-regions of Shenmu County, which are most likely to be influenced by stressor sources, was performed. Areas where risk sources have caused ecological effects on the main risk receptor have been identified. Comprehensive risk assessment results show that region (01), region (02), and region (03) were rating for class I; the typical three regions were the specific subareas where ecological effects caused by risk source on receptors were created. Through the quantitative evaluation, ecological effects occurred in the specific areas were verified. That is, water capacity loss was caused primarily by mining and trap mine drainage; the ground collapse, cracks, and soil pollution were caused by mining and coal pile up; vegetation wither resulted from ground collapse, cracks, and decline of a water table. The PETAR method seems to be operable and effective in evaluating coal mining areas'ecological risks with multiple risk sources, risk receptors, and multi-type ecological effects.