variance estimation

In the water resources planning and management، rainfall is considered as the main representative factor of region''s hydroclimate system. There is a high level of spatial and temporal variability in rainfall events. Rain gauges are used for precipitation measurement in different points of the region. Due to limitations of rain gauges development، it is impossible to measure the exact distribution of rainfall over an area، so it is needed to select the optimal number and locations of the rain gauges in a region. There are several factors that affect the optimal number and location of stations، thus، development of an optimization model for development of rain gauges network is necessary. In this study an optimization model is proposed for determining location of the rain gauges considering the transformation entropy and the regional rainfall estimation error. In this model، the points with the minimum transformation entropy and the maximum rainfall estimation error are considered as candidates for development of new stations. The results of two considered criteria are combined to determine the location of the new stations. Geogrpahic information system (GIS) is used to better represent the results of rainfall spatial analysis and explain results of the proposed optimization model. A sub basin of Karkhe basin in South West of Iran has been considered as the case study of this study. Results show that using new rain gauges which are determined to be 17 using the proposed approach could improve accuracy of spatial analysis of rainfall siginficiantly.