基于植被指数和地表温度的干旱监测方法的对比分析

以陕西省关中平原和渭北旱塬为研究区域,应用1999-2005年每年5月上旬的AVHRR卫星遥感数据,对比分析了基于归一化植被指数(NDVI)和地表温度的几种干旱监测方法:包括条件植被指数(VCI)、条件温度指数(TCI)、距平植被指数(AVI)和条件植被温度指数(VTCI)等,研究了VTCI与其他干旱监测方法的优缺点及其在研究区域的适用性.从研究区域旱情分布来看,VCI的干旱监测结果不符合研究区域干旱的分布规律.从监测结果的影像纹理特征来看,VTCI和AVI可能适合于研究区域的旱情监测.通过进一步对比分析遥感干旱监测结果与累计降水量的监测结果,得出了VTCI更适合于研究区域的干旱监测.

COMPARISON STUDY ON NDVI AND LST BASED DROUGHT MONITORING APPROACHES

This work is to study suitability of several drought monitoring approaches based on normalized difference vegetation index and land surface temperature,namely vegetation condition index(VCI),temperature condition index(TCI),anomaly vegetation index(AVI) and vegetation temperature condition index(VTCI).The study area is the Guanzhong Plain and Weibei Tablelands of Shaanxi Province in Northwest China.The NOAA-AVHRR remotely sensed data acquired at daytime under clear sky conditions on the first ten days of May in the years from 1999 to 2005 are selected for the study.From the spatial distribution of droughts,the VCI monitoring results are not in agreement with regional drought distribution,therefore,VCI approaches are not suitable for monitoring droughts.Form the image texture of the drought monitoring results,VTCI and AVI approaches might be suitable.From the further comparison study of VTCI and AVI drought monitoring results and precipitation based drought monitoring results,it can be concluded that VTCI is a more suitable approach for the regional drought monitoring.