a case study of Herat City and Surrounding Districts, Afghanistan Yusufi, Maryam creator Nguyen, Duc Hoang Examination committee Shrestha, Sangam Chairperson Babel, Mukand Singh Examination Committee Pandey, Vishnu P. External Expert AFG Western Basins Water Resources Management Project Scholarship donor text series technical report th Pathum Thani, Thailand Asian Institute of Technology 2017 continuing eng 135 leaves : ill. (some col.) Climate change is immensely affecting water resources. One of the vital resources of fresh water is groundwater which plays a significant role in fulfilling water demands of arid/semi- arid environments. Afghanistan{u2019}s dry weather with annual rainfall of lesser than 300 mm and remarkably high evapotranspiration rates makes it significantly dependent on groundwater resources. Therefore, this study aimed to examine the climate variability and change in Herat City and surrounding districts which is located in lower Harirud basin in Western Afghanistan, and assessed the vulnerability of groundwater resources under climate changes. Three Regional Climate Models (RCMs), namely ACCESS, CNRM-CM5, and MPI-ESM under RCP 4.5 and RCP 8.5 were used for projection of future temperature and rainfall of the basin. The linear scaling bias correction method was used to remove the bias and downscale the RCMs data. The impact of climate change on groundwater recharge, and surface runoff was quantified based on spatial and temporal variations using Soil and Water Assessment Tool (SWAT). The percentage change of future spatial recharge and surface runoff for each subbasin were derived. Furthermore, considering exposure, sensitivity, and adaptive capacity components of the watershed, groundwater vulnerability maps to climate change of Herat City & surrounding districts were derived for future periods under different RCMs projections. The experts{u2019} opinions were gathered through questionnaire for assigning weights to indicators. A multi-criteria decision making technique named AHP was used to derive final weights of indicators. By having the spatially and temporally detailed vulnerability maps, adaptation options are proposed for future management of groundwater resources of Herat City & surrounding districts. The average annual temperature is projected to increase up to 2.5 {u00BA}C, and 5.4 {u00BA}C under RCP 4.5 and RCP 8.5 respectively by 2100. The rainfall projection varies with RCM. ACCESS model result showed 2.4% and 6% decrease in rainfall by 2100 under RCP 4.5 and RCP8.5 respectively. Moreover, CNRM-CM5 model projected 10% decrease in rainfall by 2100 under RCP 4.5 but it showed 3% increase of rainfall under RCP 8.5 by 2100. The next RCM which was MPI-ESM showed completely different results of 9% and 12% increase of rainfall by 2100. Results of recharge and surface runoff changes indicate different changes under each RCM. General result of ACCESS and CNRM-CM5 showed that recharge will significantly decrease up to 25% and 45% under RCP 4.5 and RCP 8.5 respectively. Although surface runoff in 2050s indicated very high increase in most of subbasins, but considering overall results of RCMs, the surface runoff is projected to decrease by 5% and 18 % by 2100 under RCP 4.5 and RCP 8.5. The vulnerability assessment result shows slightly different degrees of vulnerability under ACCESS and CNRM-CM5. Overall, subbasins B13, B16, B19, B21 (25% of basin area) located in South-Eastern and B2, B3, B5, B6 (13% of basin area) located in Northern part of study area showed higher vulnerability of groundwater to climate change. The derived vulnerability maps for different future periods along with proposed adaptation measure could help decision makers to develop management plans and make decisions. The future research on this topic could be evaluation of adaptation measures. 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, 2017 Groundwater Afghanistan Climatic changes Case studies Asian Institute of Technology. http://203.159.5.9/ait-thesis/detail.php?q=B04446 http://203.159.5.9/ait-thesis/detail.php?q=B04446 180731 20260818132654.0