基于HJ-1B数据的作物根系土壤水分遥感监测

Monitoring Soil Moisture in Root-system Zone Based on HJ-1B Data with Remote Sensing Technology

针对作物生长期不同土层田间耗水发生变化的特点,在对植被供水指数(VSWI)和归一化水体指数(NDWI)构建原理进行分析的基础上,综合VSWI和NDWI构建了作物根系土壤水分监测指数(CRM),采用HJ-1B数据计算VSWI、NDWI、CRM等指数,基于不同指数分别建立土壤水分监测模型并对反演结果进行对比分析。结果表明:与单一指数模型相比,综合VSWI和NDWI的作物根系土壤水分监测指数与实测土壤水分的相关性更高,相关系数达0.6以上;降雨后浅层土壤含水量增高时,作物根系土壤水分监测指数反演精度提高更为明显,可减轻降雨对土壤水分监测的影响。

For the change characteristics of water consumption in different soil layers during crop growth period, based on the analytical results on the construct principles of Vegetation Supply Water Index （vSWI） and Normalized Difference Water Index （NDWI）, Crop Root Zone Soil Moisture Monitoring Index （ CRM ） was constructed by synthesizing VSWI and NDWI, the indexes of VSWI, NDWI and Crop Root Zone Soil Moisture Monitoring Index （ CRM）, were calculated according to HJ-1B data, the monitoring models of soil mois- ture were built based on the three indexes, and the inversions were compared and analyzed using the monitoring models of soil mois- ture. The results show that compared to the single-index model, Crop Root Zone Soil Moisture Monitoring Index （CRM） constructed by synthesizing VSWI and NDWI is high correlative with the soil moisture measured in the field, the correlation coefficient is over 0.6, the inversion accuracy of Crop Root Zone Soil Moisture Monitoring Index （CRM） obviously increases when the shallow soil moisture increa- ses after rain, and the influence of rain on monitoring soil moisture should be lightened.