【摘要】 土壤湿度是表征土壤含水量的一种相对变量,是地下水-地表水-大气水循环系统的核心和纽带。研究土壤湿度的分布特征及其影响因素对干旱地区的生态环境保护具有重要意义。文章基于MODIS数据,应用表观热惯量(ATI)法反演了格尔木河流域土壤湿度时空变化规律并分析其影响因素。为了研究结果的可靠性,利用Mann-Kendall方法进行了趋势检验分析,利用CLDAS数据和野外实测土壤含水量数据对遥感反演结果进行了检验验证,结果表明:2002—2016年格尔木河流域土壤湿度总体呈现上升趋势,并且通过Mann-Kendall检验分析,结果显示2008年发生突变,上升趋势明显。通过对流域不同用地类型的解译,北部盐池平均ATI值最高为0.088;中部及南部大面积裸土平均ATI值最低为0.028;自然植被与耕、林地平均ATI值分别为0.034和0.033。遥感反演土壤湿度结果与CLDAS数据和野外实测土壤含水量数据的相关性分别为0.85和0.59,相关性较高,说明遥感反演结果具有一定的可靠性。与蒸发、植被有良好的响应关系,相关系数分别为0.92和0.79。更多还原

【Abstract】 Soil moisture is a relative variable which can characterize soil water content.It is the core and connection among the groundwater,surface water and atmosphere water cycle system.It is of great significance to study the distribution characteristics of soil moisture and its impact factors on the ecological environment protection in arid regions.Based on MODIS data,this paper uses the apparent thermal inertia(ATI) method to invert the temporal and spatial variation of soil moisture in the Golmud River Basin and analyzes its impact factors.In order to examine the reliability of the results,the Mann-Kendall method is used to verify the trend test analysis.The CLDAS data and the field measured soil water content data are used to verify the remote sensing inversion results.The results show that from 2002 to 2016,the soil moisture in the Golmud River Basin generally shows an increased trend,and the Mann-Kendall test show that the mutation occurred in 2008 and the increasing trend is obvious.According to interpretation of different land types,the northern salt pond has the highest average ATI value of 0.088.The average ATI value,0.028,of the bare soil in the middle and southern areas is the lowest.The average ATI values of the natural vegetation,farmland and forest land are0.034 and 0.033,respectively.The correlations between the remote sensing inversion soil moisture results and CLDAS data and field measured soil water content data are 0.85 and 0.59,respectively,and the highcorrelation indicates that the remote sensing inversion results are of certain reliability.The soil moisture has good response relationship with vegetation and evapotranspiration,and the correlation coefficients are 0.92 and0.79,respectively.更多还原