If the observations of the Meteorological Department are data from rain gauges I would consider these as reference data. CFSR data are reanalysis data and assimilation of data and a modelling system. Often, these reanalysis data show smoothed patterns of the real climate reflecting the relatively coarse resolution of these products compared to in situ (point)measurements. Hence, statistics will be different, for instance the standard deviation (probably higher for in situ observations).

Hi Martijn,

Thanks for your response. actually my stations are located in a way that one is inside the catchment and one is outside the catchment. would the station outside the catchment be representative for the catchment as these are only point measurements. in case of CFSR again one station is outside and one inside but these are gridded data so wouldn't it be more representative. Although in CFSR there is combination of observations and model data so they might be less close to the actual measurements.

Hi Saima,

I would suggest to compare the two data sources by looking at daily, monthly and seasonal statistics (mean, standard deviation, wet day frequency, extreme values etc.). This will give you more insight in the value of CSFR data vs. station observations.

Whether you can use the station located outside your study area depends on the distance between the station and the catchment area, and the topography of the area. When the area is relatively flat and the station is close to the catchment, you can use that station to determine the catchment average rainfall and compare with the catchment average rainfall based on gridded CSFR data.

Thanks Martijn for detailed response.

My area is Hilly and the distance of outside station is around 12-15 km away when measured on flat ground.