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土壤干湿状况是监测土地退化的重要指标之一,是植物物生长发育的关键因素;准确地估计土壤湿度在时空上的分布状况对理解生态系统有着重要的意义,且对干旱区农业生产及生态重建也具有重要价值。研究分析了两种植被指数(NDVI,MSAVI)构建的特征空间参数的特征;同时,在考察点尺度上,分析了旱情指数TVDI与土壤含水量的关系;并揭示了研究区TVDI的空间分布规律;结果表明:Ts/MSAVI空间和Ts/NDVI空间干边的拟合系数均大于0.90,湿边拟合的效果稍差,而Ts/MSAVI构成的特征空间其拟合的干湿边更易相交,与地表温度结合,更能表示地表湿度的变化情况;TVDIM与TVDIN同土壤含水量表现为极显著负相关,且TVDIM与土壤含水量的相关性大于TVDIN与土壤含水量的相关性;Ts/MSAVI特征空间和Ts/NDVI特征空间反演的旱情指数TVDI,在空间分布上是较为相似的。
Soil moisture status is one of the most important indicators to monitor land degradation and is the key factor of plant growth and development. Accurately estimating the spatial and temporal distribution of soil moisture is of great significance for understanding the ecosystem. Ecological reconstruction is also of great value. In the meantime, the relationship between TVDI and soil water content was analyzed on the scale of study site, and the spatial distribution of TVDI in the study area was revealed The results show that the fitting coefficients of Ts / MSAVI space and Ts / NDVI space dry edge are both greater than 0.90, the effect of wet edge fitting is slightly worse, while the Ts / MSAVI feature space is more likely to intersect with the fitted wet and dry edge, TVDIM and TVDIN are significantly and negatively correlated with soil water content, and the correlation between TVDIM and soil water content is greater than that between TVDIN and soil water content; Ts / MSAVI The drought index TVDI of feature space and Ts / NDVI feature space inversion are similar in spatial distribution.