基于MODIS数据的农业干旱遥感指数对比和应用

Comparison and application of agricultural drought indexes based on MODIS data

以辽西北为研究区域,选取典型干旱年2009年作物(春玉米)主要生长季,采用表观热惯量(apparent thermal inertia,ATI)、距平植被指数(anomalies of vegetation index,AVI)和植被供水指数(vegetation supply water index,VSWI)3种基于不同理论的遥感干旱指数方法对土壤水分进行反演,分析其监测效果。结果表明,3种指数分别在一定程度上反映出了辽西北地区2009年的旱情趋势,但得到的反演结果并不一致;ATI在中高植被覆盖率下的监测效果高于预期结果,比较符合历史气象资料;AVI可以有效反映当年作物主要生长季各时期相对的受旱状况;VSWI夸大了植被的影响作用,存在严重的滞后性。

With northwest Liaoning Province as the study area, the authors analyzed the soil moisture content by using the method of apparent thermal inertia（ATI）, anomalies of vegetation index（AVI） and vegetation supply water index（VSWI）. The results show that the three indexes respectively in a certain extent can reflect the drought trend of the northwest area of Liaoning Province in 2009, but inversion results are not consistent, that the monitoring effect of ATI in high vegetation coverage rate is higher than expected, more in line with historical weather data, that AVI can effectively reflect the current crop growth season relative to the drought condition, and that VSWI exaggerates the influence of vegetation, which seems to be a serious lag.