基于FY-3A/VIRR数据的藏西北干旱遥感监测研究

Study on drought monitoring in northwestern Tibet by remote sensing based on FY-3A/VIRR data

藏西北地区生态环境脆弱,由于地形复杂、气候独特,该区的观测资料非常缺乏。利用遥感技术开展藏西北地区的干旱监测,能获取在空间上连续变化的地表干旱情况,对于指导该区农牧业生产具有重要的意义。基于FY-3A/VIRR的一级数据和标准旬产品(地表温度、植被指数),采用温度植被干旱指数(TVDI)进行藏西北地区的干旱监测研究,并将监测结果分别与基于EOS/MODIS数据监测的结果、同期的野外实测土壤水分数据以及气象站点的降水量数据进行了对比分析。结果表明:利用FY-3A/VIRR数据的TVDI遥感监测结果与实测土壤水分、气象站累计降水量数据均呈显著的负相关关系,通过了0.01水平的显著性检验;利用FY-3A/VIRR数据与EOS/MODIS数据估算的TVDI干旱等级空间分布特征基本一致,FY-3A/VIRR数据可以代替EOS/MODIS数据在藏西北地区开展干旱遥感监测,可为指导藏西北地区农牧业生产提供数据支持。

Because of complicated landform and harsh climate,the meteorological observation data were very scarce in northwestern Tibet,which is characterized by vulnerable ecological environment.Drought monitoring by remote sensing could obtain drought conditions with continuous changes on the surface,which was of great significance for the arrangement of agricultural and husbandry production in this area.In this paper,we try to reveal the drought in northwestern Tibet based on primary data,standard products(surface temperature,vegetation index)of FY-3 A/VIRR and TVDI(temperature vegetation dryness index).Then,the monitoring results has been compared,respectively,the results of the EOS/MODIS data monitoring,field measured soil moisture data during this period,and the precipitation data from weather stations.The results were compared with those monitoring results based on MODIS data,measured soil moisture,the meteorological observation data.It is found that the TVDI calculated by FY-3 A/VIRR showing a significant negative correlation with the measured soil moisture and cumulative precipitation,which had passed the remarkable test of the 0.01 level;they were basically the same that the spatial distribution characteristics of TVDI drought grades estimated by remote sensing using FY-3 A/VIRR data and EOS/MODIS data.Therefore,the FY-3 A/VIRR data could be used to carry out drought monitoring by remote sensing in northwestern Tibet instead of EOS/MODIS data,also available for providing data support for guiding agricultural and husbandry production in northwestern Tibet.