An accurate spatial and temporal representation of rainfall is essential
for hydrological assessments and water resources management. Rainfall is
monitored in India’s mountainous Western Ghats region via in-situ
rainfall gauging stations maintained by the Indian Meteorological
Department (IMD). However, the network is sparse, and significant
periods of data are missing. Furthermore, the IMD gridded rainfall
dataset is known to underestimate the depth of rainfall at the high
altitudes within this region. In this study, rainfall estimated by the
IMD grids and from remote sensing using the CHIRPS (0.25- and 0.05-
degree), MSWEP and PERSIANN datasets are compared to the IMD in-situ
gauged rainfall within the Western Ghats using a point-to-pixel
analysis.
The GWAVA model is utilised to determine the effect of the selected
rainfall input datasets on representing wider water resources. It was
found that the average ensemble provided the best representation of the
in-situ gauged and catchment rainfall and a better representation than
the IMD grids. It remains critical for water resources management to
ensure that in-situ rainfall gauging networks are maintained. In-situ
data sources of high confidence remain important for the continuous
development and ground-truthing of different rainfall datasets.