基于TVDI的西藏“一江两河”地区干旱监测研究

TVDI Based Soil Moisture Retrieval from Remotely Sensed Data for the Central Tibet

  • 摘要: 利用MODIS合成产品数据集MOD11A2和MOD13A2获取的归一化植被指数(NDVI)和陆地表面温度(LST)来构建Ts-NDVI特征空间。依据特征空间设计的温度植被干旱指数(TVDI)作为干旱监测指标,对2000~2011年夏季“一江两河”地区旱情进行监测分析,并利用研究区气象站地面温度数据进行相关度分析。结果表明:2000~2011年夏季“一江两河”地区重旱区主要分布在南部和沿江河谷一带,北部干旱程度较轻,大部分地区TVDI≥0.6,处于干旱区域;近12年TVDI值变化趋势为下降,年际变化显著;TVDI空间分布特征与降水空间分布非常一致,与传统气候干旱监测结果总体上表现一致;实测地表温度与TVDI两者具有较好的线性正相关性。由此可见,温度植被干旱指数(TVDI)作为高原地区大范围干旱监测反演模型具有一定的科学性和参考性。

     

    Abstract: Ts-NDVI(Normalized Difference Vegetation Index) feature space was constructed by combining 8-day composite MODIS temperature product(MODl1A2) and 16-day composite MODIS NDVI product(MODl3A2) ,It is used temperature vegetation drought index which based on the feature space as drought monitoring indicators.The results showed that the serious drought from 2000 to 2011 in summer is mainly distributed in the south and around the river valley,the drought in the northern is not so serious as other regions,while when the most of the values of the temperature vegetation drought index are in the range from 0.2 to 0.4,we can regard them as normal or light drought area.After comparing the temperature vegetation dryness index results with the traditional meteorological elements analysis method ones,the inversion result is consistent with the actual situation,what’s more,this paper draw a conclusion that they two have a better linear positive correlation.In a word,using the temperature vegetation drought index as the widespread drought monitoring model in plateau area has a certain reference and scientificity.

     

/

返回文章
返回