基于GIS的浙江省水稻遥感估产最佳时相选择

水稻遥感估产最佳时相选择应包括水稻种植面积估算最佳时相和水稻产量预报最佳时相两部分。在水稻遥感估产最佳时相选择中，由于首次引入GIS技术提取水稻可能种植区域，缩小了研究范围，植被种类也较简单一，因此仅用农作物物候历即可确定水稻种植面积估算最佳时相，而不需要考虑所有的植被类型。利用盆栽试验和小区试验研究水稻产量与不同时期的农学参数、农学参数与植被指数及水稻产量与植被指数的关系，结果表明，水稻产量与农业参数、农学参数与光谱变量的关系均以孕穗以抽穗期最好，水稻产量与光谱变量的关系则从分蘖盛期到抽穗期的极显著。因此，以孕穗期到抽穗期作为建立水稻遥感估产模型的最佳时期。再利用1998年各地的水稻发育期观测资料，确定各区水稻产量遥感最佳时相。

Selection of optimum periods for rice estimation using remote sensing data based on GIS

The optimum temporal for rice estimation using remote sensing data included the optimum temporal for rice planting area estimation and the optimum temporal for rice yield estimation. Based on GIS,the rice potential planting area was extracted. Therefore, the study area became smaller and the plant species considered decreased. So the optimum temporal for rice planting area estimation were determined through comparing the crop phonological calendars. In order to select the optimum temporal for rice yield estimation using remote sensing data,the relationships between the rice yield and agronomic parameters,the agronomic parameters and spectral variables,the rice yield and spectral variables for different development stages using field experiment data in 1989 and 1990 were studied. The result showed that the key period of rice production was from boot stage to heading stage. At last,the optimum temporal for rice yield estimation using remote sensing data was selected using the rice phenological calendars of 1998.