Prediction of meteorological and hydrological phenomena in different climatic scenarios in the Karkheh watershed (southwest of Iran)

Abstract

This research evaluates effects of climatic change on future temperature, precipitation and flow discharge in the Karkheh watershed (a watershed in south west of Iran). For this purpose, it utilizes general circulation models (GCMs) and the non parametric Mann-Kendall (MK) trend test. Considered hydrometric station is the Jelogir station at the upstream of the Karkheh dam. Base time period is 1971-2014 and future time period is 2030- 2073 for prediction of meteorological and hydrometric phenomena in the Jelogir station. For GCM model, the Canadian Climate Change Scenarios Network (CCCSN) database represents data of HadCM3 model for A2 and B2 scenarios. For using in a watershed, this research applies SDSM downscaling model and introduces predicted precipitation and temperature of future time period to IHACRES model for prediction of flow discharge. Also the non parametric Mann-Kendall trend test and the Theil–Sen approach (TSA) estimator distinguishes trend of observed and predicted data. Results of scenarios A2 and B2 have not much difference. Different climatic scenarios show that temperature increases and precipitation and flow discharge decrease, also MK test and TSA estimator represent that slope of their variations will slow down in future and most of changes are related to winter and spring.