Thesis (M. Eng.) - Asian Institute of Technology, 2020

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

Agriculture and international food security are at unprecedented risk from climate change. In agriculture and the national economy, rice production plays an extremely important position in Pakistan. Therefore, Pakistan needs an hour to determine the effect of climate change on rice productivity and to lessen the impacts by using agricultural adaptation measures in district Sialkot. District Sialkot has the 2nd largest production of rice in Punjab, Pakistan. The main purpose of this study is to assess the effect on rice production of the future climate and to evaluate the different adaptations to agriculture to mitigate climate change effect using the DSSAT model. The future Climate Scenarios were built in three MCGs CCSM4, MIROC5 and MPI-ESM-MR and downsized using the Quantile Mapping Bias Correction Technique in terms of projections from RCP4.5 and RCP 8.5 for the periods 2010-2039, 2040-2069 and 2070-2099. In future time slices, the district's maximum and minimum temperatures are to rise respectively by 0.8 to 3.7 DC and by 0.9 to 3.9 DC. The annual rainfall is also projected to decline by 1 to 9.5%. Similarly, The DSSA T model has been used to predict the effect on yield of potential climates. Results show that the production for all scenarios and all periods of time, relative to base yield is reduced by 0.97 to 22 percent. This decrease of yield can be offset by opting for various agricultural adaptation measures. It was found that the practiced agricultural adaptation measures of proper management of nutrients, irrigation, use of alternate rice variety and shifting the planting dates have been helpful in mitigating the impact of climate change. Late transplanting of rice increases the yield by 7.3 % to 16 % in future. Increasing the fertilizer application rate enhances the yield from 0.5 % to 28.10 % under future climate. Shifting to alternate varieties also increases the yield in future up to 27 %. Deficit Irrigation increases the yield from 3 % to 23 % for the future. Based on these findings change in planting dates can therefore be beneficial to adapting rice cultivation to climate change scenarios in District Sialkot of Punjab, Pakistan, through deficit irrigation, adequate Nutrient management and adoption of alternative rice cultivars.