Daily rainfall assimilation based on satellite and weather radar precipitation products along with rain gauge networks

The analysis of the spatial and temporal distribution of storm events contributes to a better use of water resources, for example, the supply of drinking water, irrigation practices, electricity generation and management of extreme events to control floods and mitigate droughts, among others. The traditional observation of rainfall fields in Mexico has been carried out using rain gauge network data, but their spatial representativeness is unsatisfactory. Therefore, this study reviewed the possibility of obtaining better estimates of the spatial distribution of daily rainfall considering information from three different databases, which include rain gauge measurements and remotely sensed precipitation products of satellite systems and weather radars. In order to determine a two-dimensional rainfall distribution, the information has been merged with a sequential data assimilation scheme up to the diagnostic stage, paying attention to the benefit that the rain gauge network density has on the estimation. With the application of the Barnes method, historical events in the Mexican territory were analyzed using statistical parameters for the validation of the estimates, with satisfactory results because the assimilated rainfalls turned out to be better approximations than the values calculated with the individual databases, even for a not very low density of surface observations. HIGHLIGHTS The merging of the three databases considered allows for determining satisfactory approximations of the rainfall fields analyzed, regardless the rain gauge network configuration.; The increment in the error rates of the assimilated rainfall estimates is mainly due to the lack of accuracy of the remote sensing products.; The recovery of the spatial behavior of historical storms is possible.;