水文分析中干旱指标spi的计算代码，可计算多时间尺度的指标，黏贴成m文件即可，文件内有注释描述。-Spi hydrological drought index analysis of the calculation code, and calculate multi-time scale of the index, you can paste into the m file, file comments within the descr iption.

estimate drougth frequency for 100 years using SPI index

求算标准化降水指数SPI值的MATLAB程序，用于求算综合气象干旱指数CI值(Calculate the standardized precipitation index SPI value program)

MATLAB绘制干旱指数面积图，标准化降水指数（Standardized Precipitation Index，简称SPI）采用加利福尼亚大学欧文分校的code计算。(Drawing drought index area map with MATLAB. The standardized precipitation index (SPI) is calculated using the code of the University of California, Irvine.)