利用MODIS监测高原水稻生育期和长势的方法

Methods of Monitoring Rice Growing Periods and Growth Status by Using MODIS in Yungui Plateau

用GIS技术分离提取贵州高原上坡度<6°、面积>667hm2大坝子的地理信息,选择其中栽培水稻的大坝子为遥感监测区域,用2005-2006年MODIS的旬合成NDVI序列与地面农业气象观测站数据,分析水稻生育期、长势与NDVI值的关系。结果发现,水稻各生育期与NDVI有很好的对应关系,水稻返青后的NDVI在0.60左右,分蘖-拔节期NDVI迅速上升到0.70,孕穗-抽穗期NDVI到达峰值0.75左右,乳熟-成熟期则下降到较低点,NDVI=0.70可以作为水稻生殖生长开始点的指标。通过NDVI与同期气温资料对比分析,可以对水稻的长势进行定性预测和长势评估。

The geographic information aimed the areas of gradient 〈 6° and territorial areas of 〉 1 ha in Yungui Plateau was extracted and separated by GIS. The big basin which rice was cultivated was chosen to be the monitoring area by remote sensing. A composed ten days NDVI sequence of MODIS from 2005 to 2006 was compared to the data observed by meteorological stations to analyze the relationship between the NDVI value and growth durations and growth status of rice. The results showed that each growing period of rice corresponded with the NDVI. The NDVI was at about 0. 6 after rice regreening, and up to 0.70 rapidly from tillering to stem extension period. It reached at the peak with 0. 75 during booting and sprouting period and then turned down during milkripe and mature period. The point which NDVI was at 0.7 could be as an indicator represented the beginning of reproductive growth of rice. Comparing the NDVI to temperature at the same period, the growth status rice could be assessed and forecasted qualitatively.