Implement SPEI index suitable for WRI power-generating asset model

[deepakbaskaran]

There is a python package that can be used to calculate the SPEI (as well as other useful indices). https://climate-indices.readthedocs.io/en/latest/# https://pypi.org/project/climate-indices/

[deepakbaskaran]

SPI Index: AMS_Relationship_Drought_Frequency_Duration_Time_Scales_1993.pdf

[deepakbaskaran]

SPEI Index: A Multiscalar Drought Index Sensitive to Global Warming - The Standardized Precipitation Evapotranspiration Index.pdf

[joemoorhouse]

Hi @faridradmehr, this is the original issue, re-awakened thanks to your additions. https://github.com/os-climate/hazard/blob/main/src/hazard/models/drought_index.py Based on xclim implementation https://xclim.readthedocs.io/en/stable/ Last things to do:

• add concurrency (multi-threading) for SPEI index calculation stage (I'll add a suggested approach)
• complete tests and sanity checks of results
• perform clean run