GIS assisted modeling of potential vegetation patterns in Zhulihe River watershed of the west-central Loess Plateau, China

摘要

Zhulihe River, located in the west-central Chinese Loess Plateau, is one of the major tributaries draining to Yellow River and is characterized by continental climate. Land degradation has been a main problem in the study area. Therefore, scientifically exploring the mechanisms to restore the natural ecological environments is urgently needed to prevent further irreversible degradation and retain the multiple values of productive lands. Predicting potential vegetation in the study area is the first and foremost step to restore the natural ecological environments. In This work, the main objective is to model potential natural vegetation under the present ecological conditions. Thornthwaite's method is used in the study. It can calculate monthly humidity index (IH), monthly aridity index (IA) and the annual moisture index (IM=III -0.6 IA) that is an index of climate-vegetation classification. The IM-modeled potential natural vegetation exhibits similar patterns of the field-mapped distribution of the present vegetation. Therefore, the method can be used as an effective modeling tool for ecological planning and management in watershed scale and can be trusted to model the mutual promotion between hydrology and ecology during ecological restoration process.