摘要
利用MODIS归一化植被指数(NDVI)产品MODLT1M和MODIS地表温度产品MODND1M,计算2004—2014年陕西省月温度植被干旱指数(TVDI),基于TVDI采用一元线性回归、Theil-Sen Median趋势分析、Mann-Kendall检验等方法来研究陕西省11 a来干旱的空间分布特征、时间变化特征及干旱演变趋势,并结合气象数据进一步探究引起干旱变化的气象因素。研究表明:11 a中陕西省干旱发生频率呈现北高南低的特点,陕北、关中、陕南三大区域干旱发生的频率分别为68.2%、53.8%、22.7%,且均以轻度干旱为主;陕西省旱情主要出现在春季,11 a春季的平均TVDI值在0.6~0.7之间波动;陕西省11 a中干旱情况整体呈减弱趋势,TVDI值减小、不变、增大的区域分别占55.38%、42.89%、6.20%;TVDI与湿润指数对干旱的表征具有一致性,且年均TVDI值与年降水量呈显著负相关关系(P=0.019),降水是引起TVDI下降的一个重要气象因子。
NDVI,simple linear regression method,Theil-Sen Median trend analysis method and Mann-Kendall test method were used to calculate the monthly TVDI in Shaanxi from 2004 to 2014,thereby analyzing the spatial distribution features,temporal variation features and the evolution trend of drought. The results indicate that:( 1) The occurrence frequency of drought in Shaanxi province was higher in the north and lower in the south,with Shanbei,Guanzhong and Shannan being 68.2%、53.8% and 22.7% respectively.( 2) The drought of Shaanxi province mainly occurred in spring,the average TVDI in spring over the past eleven years varied between 0.6 and 0.7.( 3) The drought of Shaanxi province showed a downward trend as a whole.( 4) TVDI was consistent with wetness index on monitoring drought,and annual TVDI value had a significantly negative correlation with annual precipitation,precipitation was an important meteorological factor causing the decline of TVDI.
出处
《干旱地区农业研究》
CSCD
北大核心
2018年第1期221-229,共9页
Agricultural Research in the Arid Areas
基金
国家自然科学基金项目(41171310)
陕西省自然科学基础研究计划项目(2016MJ4016)
关键词
干旱变化特征
遥感
温度植被干旱指数
湿润指数
陕西省
variation of drought
remote sensing
temperature vegetation drought index
wetness index
Shaanxi
