Title: Temporal trends in precipitation using spatial techniques in GIS over Urmia Lake Basin, Iran

Authors: Farshad Fathian; Hamed Aliyari; Ercan Kahya; Zohreh Dehghan

Addresses: Department of Water Engineering, College of Agriculture, University of Tabriz, 51666-16471, Tabriz, Iran ' Department of Water Engineering, College of Agriculture, University of Tabriz, 51666-16471, Tabriz, Iran ' Department of Civil Engineering, Hydraulics Division, Istanbul Technical University, 34469 Maslak, Istanbul, Turkey ' Department of Water Engineering, Faculty of Agriculture, Isfahan University of Technology, 84156-83111, Isfahan, Iran

Abstract: Precipitation trend analysis, on distinct spatial and temporal aspects, has been of great interest due to the increased attention given to global climate change by the hydro-climatological community. The aim of this study is: 1) to detect precipitation trends using the Mann-Kendall method in annual and monthly time scales at 42 stations in the Urmia Lake Basin (ULB); 2) to evaluate these detected trends in conjunction with the spatial interpolation techniques; namely, inverse distance weighting (IDW), ordinary Kriging (OK) and completely regularised spline (CRS) using GIS model. Results showed that both decreasing and increasing trends was observed at all time scales over the basin. Assessment of interpolation methods exhibited that the OK with an RMSE value of 1.14 was the best interpolation technique according to the cross-validation results. Briefly, the OK technique is concluded as the best method in the interpolation procedures based on the cross-validation and spatial clustering outcomes.

Keywords: trend analysis; spatial interpolation; geographic information system; GIS; Urmia Lake Basin; ULB; precipitation trends; rainfall trends; Iran; spatial clustering; inverse distance weighting; IDW; ordinary kriging; completely regularised spline; CRS.

DOI: 10.1504/IJHST.2016.073883

International Journal of Hydrology Science and Technology, 2016 Vol.6 No.1, pp.62 - 81

Received: 08 Mar 2015
Accepted: 13 Jul 2015
Published online: 28 Dec 2015 *

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