青藏高原东缘地形急变流域生态水文分区研究

Eco-hydrological division of the watershed in the rapid topographic change basin on the eastern Tibetan Plateau

生态水文分区是流域生态保护和水环境管理的重要依据,青藏高原东缘地形急变流域是生态水文分区研究的典型区域之一。基于生态-水文互馈机制,以青藏高原东缘地形急变典型流域大渡河为例,从地形地貌、气候特征、生态因子和人类活动4个方面选取12个指标构建生态水文分区评价体系,综合反映地形急变流域水文-土壤-气候-生态系统全链条,量化流域生态水文指数,由SWAT模型提取的小流域尺度,刻画区域生态水文分区格局;通过生态水文分区与土地利用、自然保护区及生态保护红线的叠置分析,为流域资源开发利用保护的科学布局及生态调控提供科学依据。基于生态水文指数值及384个小流域,共划定少水生态区、平水生态区及丰水生态区3种类型区,划定结果与土地利用格局、自然保护区及生态保护红线分布有较好的契合度。

Eco-hydrological division is an important basis for watershed ecological protection and water envi⁃ronment management.The watershed in the rapid topographic change basin on the eastern Tibetan Plateau is one of the typical areas for eco-hydrological zoning research.Based on the ecological hydrological mutual feed-back mechanism,an evaluation index system of eco-hydrological division is constructed,with 12 indi⁃cators from four aspects of topography,climatic characteristics,ecological background and human activities,which can comprehensively reflect the entire chain of hydrology-soil-climate-ecosystem in a river basin with rapidly changing terrain.Taking the Dadu River Basin as an example,this paper quantified the ecolog⁃ical hydrological index value of the basin,extracted small watersheds based on the SWAT model,and de⁃scribed the regional ecological hydrological division pattern;Through the analysis of the superposition of eco⁃logical hydrological divisions and land use types,nature reserves and ecological redlines,a scientific basis for the development,utilization,protection and ecological regulation of watershed resources was provided.Based on the value of the ecological hydrological index and the extraction of 384 small watersheds,three types of zones were delineated,the less water ecological zone,the water balanced ecological zone,and the multi-water ecological zone.The delimitation results were in good agreement with land use types,nature re⁃serves and ecological red lines.Attention should be paid to the ratio of production and living spaces in less water ecological areas,to coordinate the contradiction and balance between production and living water and ecological water demand,and to serve the land and space planning of the river basin.