滇池流域水生态功能一二级分区研究

Research of levelⅠand Ⅱ aquatic ecological function regionalization in Lake Dianchi basin

水生态功能分区是流域水资源管理、水环境保护、水生态恢复的基础,尤其是与人类活动紧密相连而又矛盾重重的湖泊流域,其水生态功能分区是实现流域可持续发展的必要条件,而如何科学合理地对湖泊流域进行水生态功能分区,成为流域综合管理过程中亟需解决的问题.以滇池流域为例,立足于滇池流域水生态系统存在的问题,确定了流域一、二级水生态功能区的主导功能;以水文完整性为基础,分别针对一、二级分区划分子流域单元;以生态功能区划的生态系统服务功能、尺度效应、地域分异规律等相关理论为基础,识别影响滇池流域水生态功能的关键因子,构建滇池流域一、二级水生态功能区的指标体系;对多指标进行空间叠加聚类,并根据滇池流域的水量水质特征对分区边界进行微调,将滇池流域划分为5个一级区和10个二级区;同时采用着生藻、水丝蚓的生物密度对分区结果进行合理性评价;在此基础上,对水生态功能分区存在的问题进行探讨.

The aquatic ecological function regionalization is the basic requirement of water resources management,water environment protection and water ecology restoration. Especially for lake basins which are connected closely with human activities and filled with inconsistencies,the aquatic ecological function regionalization is an indispensable condition of realizing sustainable development in the watershed. So how to delineate reasonable ecological function regionalization becomes the major issue to be addressed in the integrated watershed management. In the case of Lake Dianchi basin,the dominant water ecological functions are first determined according to the current problems of water ecosystems. And in the premise of hydrological integrity,sub-catchment units are divided for the first and the second level regionalization respectively. Then we indentify the key factors that affect water ecological function significantly and construct the index system for the watershed based on the relative theories,including ecosystem service function,scale effect and rule of territorial differentiation. The overlaying and clustering methods are used for multiple indices. Then final boundary is adjusted slightly according to water quantity and quality distribution. The consequence shows that Lake Dianchi basin is divided into 5 level Ⅰecological function regions and 10 level Ⅱecological function regions. By using the density of periphytic algae and Limnodrilus,assessment is made on the reasonability of regionalization. Finally the problems remained in the water ecological function regionalization are discussed.