IRRIGATION WATER REQUIREMENT VULNERABILITY UNDER DIFFERENT CLIMATE CHANGE SCENARIOS AT SUB-NATIONAL SCALE, EGYPT

Abstract

The agricultural sector is the highest consumer of the water demand in Egypt, and it is facing crop yield reduction due to climate change. Irrigation technologies are one of the most recommended adaptation options to meet the proposed change. Egypt`s financial resources allocated to climate change adaptation plans are limited. Therefore, determining the most governorate vulnerable to climate change in terms of Irrigation Water Requirement (IWR) is essential. This study aims to assess the vulnerability of IWR to climate change at the subnational scale based on the IPCC Third Assessment Report (TAR) definition. In this study, reference evapotranspiration (ETo) and precipitation change were selected for exposure factors, sensitivity factors, soil type, and economic value of irrigation water were chosen. Finally, we identified education, poverty, and organizational capacity for adaptive capacity factors. The estimation of ETo was carried for the data of the Coupled Model Inter-comparison Project phase 6 (CMIP6) models under four Shared Socioeconomic Pathways (i.e., ssp126, ssp245, ssp370, and ssp585). Six models were used in this study, namely BCC-CSM2-MR, CanESM5, CNRM-CM6-1, IPSL CM6A-LR, MIROC-ES2L and MRI-ESM2-0. An ArcGIS tool was developed to estimate monthly average ETo for the historical period (1970-2000) and future periods (2020-2040 and 2040-2060). All the factors data were collected and calculated, followed by normalization and then aggregating. The results show nine governorates (Al Minya, Asyut, Shamal Sina, Suhaj, Al Buhayrah, Al Fayyum, Al Isma`iliyah, Ash Sharqiyah, and Bani Suwayf ) with the highest and high vulnerability degrees located in the country's middle and north. Four governorates (Ad Daqahliyah, Aswan, Al Gharbiyah, Bur Sa`id) have the lowest vulnerability degree under the climate change scenarios (SSP126, SSP245, and SSP370), and one governorate (Aswan) out of these four has the lowest vulnerability degree under the SSP585 scenario. The study output illustrates that the highest vulnerability governorates have at least two vulnerability components with a high degree. The study results are presented to be clear for the decision-makers to choose the best adaptation plans and may be support the research for adaptation and mitigation strategies effective design.