An investigation on the climate change and drought types in the Porsuk Stream Watershed, west of Turkey

Abstract

Climate change is a major parameter affecting agriculture. The aim of the study is to determine the effect of climate change on agricultural and hydro-meteorological drought in the Porsuk Stream Watershed. In this study, drought analyses in the watershed had been conducted using the past (1970-2018) and future (2020-2100) climate data produced according to the RCP 4.5 and 8.5 scenarios of the HadGEM2-ES model, with the help of Standard Precipitation Index (SPI), Standard Runoff Index (SRI) and Palmer Drought Severity Index (PDSI). The analysis revealed that the watershed was located in a dry region, it was detected that agro-hydrological droughts were dominant, and a meteorologically normal climatic situation prevailed in the past. Sub-basin in the watershed where agricultural drought is experienced severely are Odunpazari, Alpu and Tepebasi, respectively. 1981, 1986, 1989, 2008, 2013, 2015 and 2018 years were arid, while the driest years are expected to be 2056, 2058, 2069, 2070, 2089, 2096, the wettest year is expected to be 2021. The Porsuk Stream Watershed inclines to be dry meteorologically and humid hydrologically in the future. From the point of agricultural drought, although there is a potential for a drought over time, it is detected that a normal climatic situation will prevail throughout the watershed. Compared to the reference (1970-2000) period, climate change will happen in the manner of temperature and precipitation increases in the future. As a result of the study, important data about drought were produced for farmers.