Introduction of Application of Temperature Vegetation Dryness Index in China
Reducing of vegetation index and rising of surface temperature are two kinds of important physiological performance of plants when they are under severe drought stress,so remote -drought indices based on vegetation index(VI)and land surface temperature (LST)are commonly used in drought monitoring.Indices based on vegetation index are difficult to exclude the influence of irrigation, pest and the flood disasters,and due to their larger lag time,they are difficult to monitor drought events which occurred suddenly.The land surface temperature is rising rapidly under the condition of water deficiency,so the indices based on land surface temperature (LST)can detect drought events,but it can’t distinguish water stress conditions under different vegetation cover and it’s easy to be influenced by the surface heat exchange and soil background temperature.The temperature vegetation drought index(TVDI)based on spectral feature space combined the vegetation index and land surface temperature,its physical meaning is more definite and it is well defined.TVDI could overcoming the deficiency of using VI and LST only,there for it is widely used to estimate evapotranspiration and soil moisture.For well understanding the application situation of TVDI in our country and the method to calculate and improve it,this paper expounded the principle of TVDI firstly,and then gave a detail introduce about the calculation and improving methods as well as the way of monitoring drought based on TVDI,etc.The aim is to offer some reference for the calculation and application of TVDI.
NETL
NSTL
万方数据
维普
