基于保护目标制定的湖泊流域入湖河流河段划分方法——以滇池流域为例

通过科学合理地划分河段实现栖息地分类管理是恢复流域生物完整性的重要内容之一.湖泊流域入湖河流空间尺度小、坡降大、生态学过程差异性显著的特点导致其河段类型复杂多样,与河流流域河段类型的大尺度特征具有明显区别,因此,河流流域河段划分指标及其方法不适用于湖泊流域,亟需发展以栖息地分类管理为目的的湖泊流域河段划分方法.本文通过回顾河流分类的概念、划分依据及划分方法的发展历程,明确了湖泊流域河段划分理论基础,提出了基于保护目标制定的湖泊流域河段划分方法,为恢复湖泊流域生物完整性提供了更为精细的管理单元.同时,以滇池流域为例,通过筛选与大型底栖动物敏感种群和濒危种群显著相关的环境因子,建立了由地貌类型、土地利用方式、河水来源、河道人工化情况及水体营养程度构成的指标划分体系;在实现各划分指标空间化的基础上,利用空间叠加聚类技术手段,将滇池流域入湖河流划分为9个河段类型,为滇池流域水生态系统健康恢复提供了科学依据.

The method of river classification based on protection targets in lake basins:A case study of Lake Dianchi Basin

Classified management of habitats through river classification in a scientific way has been one of the priorities for restoring biological integrity. The features of small spatial scale, large gradient and the obvious heterogeneity of ecological processes, are totally different from the large-scale characteristics of the river reaches in river basins, resulting in diverse types of river reaches in lake basins. Therefore, the methods of river classification for river basins are not applicable in lake basins. It is urgent to explore the method of river classification in lake basins in the purpose of classifying and managing aquatic habitats. In this study, in order to provide a more precise unit for promoting biological integrity, the method and its indexes based on protection targets in the whole lake basin were proposed by reviewing the concepts, basis and methods about the classification of rivers in the past few years. In the case of Lake Dianchi Basin, after selecting the environmental factors significantly related to sensitive and endangered species of macrozoobenthos, the index system was constructed with geomorphology type, landuse type, water source, channelization and water nutrient. Based on spatializing each of five indexes, nine types of river reaches were obtained by intersecting and clustering of river reaches, which provided relevant basis for recovery of ecosystem health in the whole basin.