气象干旱指标计算程序，已经集成为arcgis工具箱，导入后即可使用 也可在py环境下直接运行(The meteorological drought indicator calculation program has been integrated into the arcgis toolbox and can be used after import. Can also run directly in py environment)

标准化降水蒸散发指数 matlab的代码(Standardized index precipitation evaporation for matlab)，直接按照例子中的数据格式运行SPEI_Cal.m文件，运行结果在stacking中查询，可以自己修改时间尺度，亲测可用。(The program calculates a time series of the Standardised Precipitation- Evapotransporation Index (SPEI) at a g