Vesuviano, G.; Griffin, A.; Stewart, E.; Cole, S.

Gridded rainfall depth-duration-frequency (DDF) estimates for the state of Kerala, India, 1979-2020

Name: Gridded rainfall depth-duration-frequency (DDF) estimates for the state of Kerala, India, 1979-2020
Published: 2022-11-22
License: https://eidc.ceh.ac.uk/licences/OGL/plain

https://doi.org/10.5285/4a08e6f1-e508-4bb6-b571-b3145dd1588e Cite this dataset

This data represents twenty-four modelled rainfall depth estimates by GridASCII files across the state of Kerala, India, for four durations (1, 6, 24 and 192 hours) and six return periods (2, 5, 10, 25, 50 and 100 years). The estimates were produced using a similar procedure to the Flood Estimation Handbook statistical method for flood frequency estimation: separately for each duration, the estimated median annual maximum (AMAX) rainfall was used as a standardizing “index” value and the estimated L-moments of the AMAX series were used to fit a generalized logistic distribution “growth curve”. The data are in units of mm at a spatial resolution of 0.12 degrees.

Publication date: 2022-11-22

Format

ASCII grid

Spatial information

Study area
Spatial representation type: Raster
Spatial reference system: WGS 84

Provenance & quality

1, 6, 24 and 192-hour annual maximum rainfalls were extracted from the gridded Indian Monsoon Data Assimilation and Analysis (IMDAA) hourly rainfall dataset for each year of 1979-2020 inclusive, for each grid cell in the state of Kerala, India. At each point, the median, and L-moments of the 42 annual maxima were calculated separately for each duration. At each location, linear regressions were created for the median using longitude, latitude, duration and mean annual rainfall. Linear regressions were created for the first two L-moments using these descriptors variables plus altitude and modelled median of annual maxima. The generalized logistic distribution was then used with the modelled median and L-moment ratios at each site to estimate the rainfall depths associated with specified durations and return periods.