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目前对大尺度、复杂地表覆盖类型的区域干旱监测研究仍然是一个难点。文中尝试选择近红外、短波红外、热红外波段组合成新的干旱指数,并选取甘肃定西市、庆阳市、平凉市、宁夏固原市等为研究区。在比较各种不同的干旱指数优缺点的基础上,采用MODIS 1B数据的第2,6波段和LST(Land Surface Tempera-ture)产品合成多波段干旱指数。并用降雨量计算SPI(Standardized Precipitation Index),以及日均相对湿度与多波段干旱指数进行全面比较。结果发现在干旱年份,该指数与气象数据有较好的相关性,说明其在大尺度、较复杂地表覆盖类型区域旱灾监测有一定前景。
At present, the research on regional drought monitoring of large-scale and complex land cover types is still a difficult task. In this paper, we try to select the near infrared, shortwave infrared and thermal infrared bands to form a new drought index, and select Dingxi City, Qingyang City, Pingliang City, Guyuan City, Ningxia as the study area. Based on the comparison of the advantages and disadvantages of various drought indices, the multi-band drought index was synthesized using the MODIS 1B data of the 2nd and 6th bands and the LST (Land Surface Tempera-ture) products. The SPI (Standardized Precipitation Index) was also calculated and the daily average relative humidity was compared with the multi-band drought index. The results showed that there was a good correlation between the index and meteorological data in drought years, indicating that it has some prospects for drought monitoring in large-scale and complex land cover types.