Sustainable Water Resources Management Strategies and its Implications in the Irrigated Areas of the Indus Basin of Pakistan

Abstract

Pakistan's agriculture relies heavily on the Indus basin, where 90% of the land is cultivated under irrigated agriculture. Limited water resources, poor irrigation practices, and inadequate water management pose a serious threat to the country's food security and economy. Recently, the Government of Pakistan has been working to implement a national water policy aimed at promoting the sustainable use of water resources. The policy targets the adoption of sustainable water−saving strategies for future irrigation practices. In this dissertation, alternative water management strategies are evaluated, including replacing water−intensive crops with less water−intensive ones and implementing improved irrigation technologies to replace less efficient surface irrigation methods. Furthermore, the impact of these alternative water management strategies is also investigated under climate change Representative Concentration Pathways (RCP2.6 and RCP8.5). The results show that up to 35% of water use can be reduced by using optimal cropping patterns and up to 50% by using both optimal cropping patterns and improved irrigation technologies under current climatic conditions (baseline scenario). While in the climate change scenarios, water consumption could be restrained by up to −3% compared to the status quo through the adaptation of alternative cropping patterns. Additionally, the results show that future water consumption under climate change could even be further decreased by up to −19% through the collective implementation of improved irrigation technologies and optimized cropping patterns. In a follow-up study, the site−specific greenhouse gas emissions of CO2 associated with groundwater pumping, irrigation system operation, and bicarbonate extraction from groundwater are analyzed. Additionally, the associated costs and effects on groundwater depletion are assessed, assuming that yields remain stable. Various energy sources, such as solar power, are incorporated into the scenarios for improved irrigation technologies. Results indicate that a reduction in net CO2 emissions is only possible via the extensive use of solar−powered systems, where net CO2 emissions can decrease by up to 81%. All improved irrigation technologies result in increased irrigation costs but reduced groundwater depletion. If all scenarios are considered concerning the sustainability aspects examined, the solar system is by far the best option.