基于MODIS的渍害田和正常农田遥感特性对比研究

渍害田在我国南方地区分布广泛，严重影响农业生产。以四湖流域洪湖地区为实验区，基于渍害田的物理及生态特性来探讨渍害田遥感识别特性。利用2002～2011年MODIS产品，辅以土壤图、土地覆被数据，对比分析了正常农田及渍害田在反照率、增强型植被指数（EVI）、地表夜温、地表温差和表观热惯量的时相差异；并结合相关研究成果加以解释和验证。结果表明：一年中大部分时段，正常农田的反照率、EVI、地表温差都大于渍害田，而地表夜温、表观热惯量都低于渍害田；各指标的多年平均值也具有类似差别；渍害田的EVI在6、7月份比正常农田高, 可能是由于渍害田在雨、热、肥条件同时良好时比正常农田生长的更快。研究结果可为进一步准确识别渍害田空间分布及其动态变化

REMOTE SENSING CHARACTERISTICS COMPARATIVE STUDY BETWEEN WATERLOGGED AND NORMAL CROPLAND IN THE SIHU BASIN BASED ON MODIS

The waterlogged cropland,which seriously affects the farm production, is widely distributed in south China. In this paper,the physical and ecological characters of the waterlogged cropland and its identification using remotely sensed image in Honghu,Sihu watershed are studied.Based on data including the MODIS products from 2002 to 2011,the soil and land cover data, the differences between the normal and waterlogged cropland in albedo,Enhanced Vegetation Index(EVI),land surface night temperature,land surface temperature between day and night and apparent thermal inertial are compared systematically.The differences between these indices are interpreted and proved based on the early researches.Result shows that the values of albedo,EVI and land surface temperature between day and night of the normal cropland are higher than those of the waterlogged cropland,whereas the values of land surface night temperature and apparent thermal inertial are lower than those of the waterlogged cropland throughout the majority of the year.The differences of the five indicators are also reflected in the mean values of these indicators.The EVI of the waterlogged cropland is higher than the normal cropland in June and July.Maybe the waterlogged cropland grows faster than the normal cropland when all the factors such as rain,heat and fertiliser in good condition.These characters provide useful information for the identification of the spatial pattern and dynastic change of waterlogged cropland