Study On The Ecography Method Of Loess Torrent Watershed

The Loess Torrent is a common type of mountains watershed and important unit of recharge and discharge on the Loess Plateau.The defects of the watershed drainage paradigm that based on grey hydraulic engineering have been gradually appeared.Contrary to the watershed drainage paradigm,the watershed storage paradigm advocates that the function of watershed ecostructures should be exerted to regulate the basin water behavior.Such a nature-based watershed management paradigm is receiving increasing attention in the world.The ecostructures of Loess Torrent watershed is composed of regolith,habitat and energy,through ecography method to investigate and mapping watershed ecography is of great significance to further explore the watershed ecostructures and reveal the operation law of the watershed ecosystem.By analyzing watershed ecostructures,this study proposed the principle of watershed ecography,demonstrated the relationship among the regolith,habitat and energy of the basin,and summarized the functions of the ecostructures of the basin.Based on the principle of watershed ecography,proposed the ecography method,and taking the Sanyanjing watershed as an example,this study carry out the regolith mapping,habitat mapping and energy mapping.Based on the results of watershed ecography,the landscape pattern of Sanyanjing watershed was analyzed,and then the comprehensive index model and analytic hierarchy process were used to evaluate the ecostructures health of the watershed.This study shows that :(1)In the view of complex open systems such as ecological coupling of the Regolith-Habitat-Energy continuum and the water storage basin-headland sequence,and based on the principle of watershed ecological structure under complex open systems,this study followed the principles of uniqueness and learning by doing,and applied geographic information technology and social survey methods to carry out sustainable mapping and modeling research on the watershed through a comprehensive analysis of the natural and socialecosystems of the watershed,so as to provide a basis for sustainable watershed management.(2)The watershed ecography which is based on complex open systems has received more and more attention at domestic and abroad.In this paper,a case study of the Sanyanjing watershed has been carried out to obtain good results,which is a beneficial exploration to further deepen the understanding of the watershed ecosystem.(3)The watershed ecography method was summarized and practiced,and it is suitable for small watershed on the Loess Plateau,and the regolith,habitat and energy of the watershed were mapped respectively,and the health status of the watershed ecostructures was evaluated based on the mapping results,which proved that the watershed ecography method was effective on the small watershed scale.Watershed ecosystem is a complex open system in nature,and its ecostructures is an organic coupling whole,which affects the balance of watershed ecosystem.It is a trend to study the ecological coupling of the Regolith-habitat-Energy continuum,and the ecography method can be used as an effective method to provide technical support for it.