基于环境容量的汶川地震重建规划区环境适宜性评价

Environmental suitability assessment of Wenchuan Earthquake region based on environmental capacity

基于对四川汶川地震中受灾严重的51个县1271个乡镇的水环境容量估算,对不同地域的环境适宜性进行评价,旨在为震区恢复重建的人口、经济布局提供一定科学依据。水环境容量选择COD和NH3-N两个指标进行评价,首先利用降雨量、径流系数和径流深等参数评价单元的径流量,再根据水环境质量标准、水体自然背景值等参数估算环境容量;进而在水环境污染胁迫程度计算的基础上,进行了环境适宜性评价。结果显示:水环境容量区域性差异明显,北部三省交界区域的乡镇容量较高、东南部四川盆地边缘和内部区域的乡镇容量较高、西部的山区乡镇环境容量低;西南部污染胁迫程度较低,环境适宜性较高;西部自然保护区胁迫程度较大,环境适宜性较低;成都平原附近县域胁迫较大,环境适宜性较低;环境适宜性区域性明显,但也呈现出一定的分散性。

Based on the calculation of water environmental capacity 1271 towns among the 51 most seriously affected counties in the Wenchuan Earthquake zone, Sichuan Province, the environmental suitability of different regions was assessed in order to provide a scientific reference point for the population and economy in post-Wenchuan Earthquake restoration and reconstruction. COD and NH3-N were used to assess water environmental capacity. First, the runoff amount of every unit was calculated using parameters such as rainfall, flow coefficient and runoff quantity; second, environmental capacity was estimated from the water environmental quality standards and water background quality; finally, environmental suitability was assessed based on calculation of the degree of water pollution stress. The results showed： （1） regional differences in water environmental capacity i the water capacity of villages and towns in the northern tri-province boundary region, the southeastern edge and the inner Sichuan Basin was high, while that in the western mountain area was low; （2） water pollution stress in the southwest was low and environmental suitability was high; （3） water pollution stress in the natural protection area in the western region was high and environmental suitability was low; （4） water pollution stress in areas close to the Chengdu Plain was high and the environmental suitability was low; （5） The distribution of envirenmental suitability level presents clear regionality as well as some dispersivity.