A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Water Engineering and Management

Thesis (M.Eng.) - Asian Institute of Technology, 2019

The intensity and frequency of climate sensitive hydro-meteorological extreme events have been significantly increased since 1970s. Drought is an environmental disaster that adversely affects the human, agriculture, land surface, river flow and the environment. The aim of this study was to quantify the impact of drought on the wheat yield of Pakistan under climate change scenarios. To identify the historical and future drought, SPI drought index was used. Two RCMs (ACCESS-CSIROCCAM & CNRM-CM-CSIROCCAM) was used. It was found that the rainfall is projected to increase in future under RCP 4.5 and RCP 8.5 scenarios. Future drought characteristics showed that drought frequency of the mild and moderate drought is expected to increase in future. Drought impact on wheat yield was calculated at Faisalabad, Gujranwala and Chakwal station by AquaCrop model. It has been observed that about 13.1 % and 12.4% yield is projected to reduce in future due to drought under RCP 4.5 and RCP 8.5 respectively at Faisalabad (canal irrigated) station. Similarly, at Gujranwala (tubewell irrigated) station 13.1 & 17.9% and at Chakwal (rainfed) station 24.8 & 26.4% yield is expected to reduce in future under RCP 4.5 and RCP 8.5 respectively. Laspeyres GDP index for the normal years and drought year was calculated at all three stations. It was observed that Laspeyres index value in drought year was less than normal year value. It was noticed that from 2031-34, drought affect the crop yield at all three stations, which indicated that during this duration drought might be affect the whole study area.