Merging rainfall data of ground and satellite measurements in order to correct and improve the performance of data at the catchment area (Case study: Mond Basin)

Estimation of precipitation as one of the most important factors affecting human life and activities is one of the most important issues of interest among decision makers such as water resource managers, farmers, industry owners, and in general, water and climate researchers, especially in arid and semi-arid regions of the world.  However, so far, access to real rainfall in the basins, especially the mountainous basins, is a vague and complicated issue. Precise measurements of precipitation in not usually possible in these basins due to environmental conditions and relatively moderate spatial changes in rainfall.At present, there are various methods and tools for measuring rainfall or estimating it (Barrett, 1970, Rabiei et al., 2013), which includes: 1) Ground rain-gauge stations 2) Ground radars 3) Satellite estimates. But the most common method is to measure rainfall are meteorological radar Cremonini et al, (2015) and ground rain gauge stations (Acquaotta et al., 2016). The ground rain-gauge stations are usually used by sensors or rain measuring devices. They represent direct measurements of rainfall over the ground (precipitation depth), but they are not able to transmit the spatial pattern of precipitation (Huff, 1970). Meteorological radars and satellite data, on the other hand, are capable of recording and estimating rainfall data with high spatial and temporal resolution. However, considering the variable rainfall uncertainties in this type of data, they are not able to accurately estimate rainfall (Jordan et al. 2000). To solve this inherent problem, there is a need for a methodology that uses all methods of rainfall measurement in the best way. The most commonly used method for reconstructing the precipitation rate with higher accuracy is based on comparison of satellite observations or meteorological radars with ground measurements recorded by rain gauge stations that are spatially dispersed appropriately. In this research, in order to combine and correct the rainfall data, appropriate methods for the integration and correction of rainfall data using rain gauge stations and satellite images at the basin level have been used.