Study On Real-time Monitoring Of Double-crop Rice Area Based On MODIS Data

In this experimentation,we had set up four rice observation points in Jiangxiang town,Nanchang County,Jiangxi Province during 2007 and 2008. Observing the growth of double-crop rice, every eight days,we recorded dry weight, wet weight,plant height, leaf area index (LAI), the changes in the depth of paddy field irrigation and management measures.This paper analysed the relationship of the MODIS vegetation indices and field sampling data, established the model of real-time monitoring of rice and the late rice production estimation model.The results showed that, MODIS-EVI (Enhanced Vegetation Index) and LAI have a strong correlation at the rice tillering stage and milky stage than NDVI(Normalized Difference Vegetation Index), LSWI(Land Surface Water Index),which more suitable for research hot.LSWI has a strong monitoring capacity for late rice water content in the heading and milky stage. In tillering stage rice leaves can not completely cover the surface of paddy fields.LSWI had been effected by paddy fields irrigation water and leaves.After the tillering stage, LSWI has a strong relationship with rice water content.In the early period of rice growth, the relationship between vegetation index and LAI is lower than the late rice,especially in 2007. This result showed that MODIS is not suitable for monitoring early rice in the study area.MODIS-EVI can be used to monitor and estimate the biomass in the tillering stage and milky satage of late rice. In the late rice tillering stage and milky stage, MODIS can be used to estimate the rice production,but in early rice,the result is not yet clear.