Comparison of Present and Potential Spatial Distribution of Vegetation in the Groundwater-Fluctuating Belt in the Lower Reaches of Heihe-River Northwestern China

The present and potential spatial distributions of vegetation were estimated respectively by remote sensing data and a logarithmic normal distribution model in the lower reaches of Heihe River, northwestern China. The results show: (1) the comparability of the potential and present spatial distribution of Populus euphratica is 66.3% and Tamarix ramossima is 74.7%; (2) the higher comparability of the potential and present spatial distribution indicates that the groundwater level is the decisive factor in the changes of spatial distribution of Populus euphratica and Tamarix ramossima in the study area. The difference is obvious between the potential and present spatial distribution of Populus euphratica and Tamarix ramossima in the distribution region of hardy salt layer. This study is an important reference for analyzing the relationships between vegetation distribution and groundwater level.