Regional analysis of maximum daily precipitations of Aegean Region

The two major objectives of the regional analysis are to estimate the T-year event magnitude at a given location in a statistically homogeneous region, mainly at ungauged sites, and to improve at- site estimates with large sampling errors because of the limited data. In this paper, an index method, based on the two ? parameter lognormal distribution as a parent one for the regionalization of annual maximum daily precipitations recorded at Ege Region of Turkey was presented. In addition to the procedure proposed by Wiltshire (1986) for identification of homogeneous sub clusters, a special student-t test based on the lognormal assumptions was applied in order to decide whether a given station is indeed a member of its individual sub cluster or not. The average regional coefficient of variation values computed as BCV,Ege= 0.3334; BCV,KuzeyEge= 0.3355; BCV,GüneyEge= 0.3299; BCV,KıyıEge= 0.3417; BCV,İçEge= 0.3252. After the determination of statistically homogeneous region, regional dimensionless growth curves are computed upto regional parameters. The maps of spatial distribution of basic statistics are prepared. By use of the prepared maps, estimation of the T-year event magnitude of a hydrologic variable could be done, mainly at ungauged sites or at the sites of which has limited data.