Publications Details
Publications Details



Author: Tayebeh Zinati, Shahram Khalighi

Year: 2009

Publisher: European Water Resources Association (EWRA)


Prediction of daily rainfall over a region is one of important issues in water resources management and planning. Accurate estimation of the spatial distribution of rainfall is critical to the successful modeling of hydrologic
processes. The ability of obtaining high resolution estimates of spatial variability in rainfall fields becomes important for identification of locally intense storms which could lead to floods. The accurate estimation of the spatial distribution of rainfall requires a very dense network of instruments, therefore, it is the necessary to estimate point rainfall at unrecorded location from values at surrounding sites. In this study, 3 methods were used to estimate annual rainfall using interpolation techniques in GIS system. These methods were: Inverse Distance Weighted (IDW), Kriging, and Spline. These geostatistics method, which is based on the theory of regionalized variables, is increasingly preferred because it allows one to capitalize on the spatial correlation between neighboring observations to predict attribute values at unsampled locations and dose not that ignore both the elevation and rainfall records at surrounding stations. The data set including daily rainfall collected from rain gauge stations of study area were used. Normality and homogeneity of data were examined. Elevation
was used as co variable and its correlation with rainfall evaluated. Variographic analysis using three different techniques were applied for predicting annual rainfall then statistical comparison of the results obtained by three methods.