Understanding and mitigating water resource decline in the Deli watershed: a comprehensive analysis

Abstract

Abstract In Indonesia, the common method for determining water resources' carrying capacity in an area has been the comparison of water availability and water demand. However, water resources' carrying capacity constitutes a complex system with interrelated variables that interact and influence one another. This study employs both the System Dynamics and the Analytic Hierarchy Process (AHP) approaches, which are subsequently integrated to develop an index that effectively represents the status of the water resources' carrying capacity, to investigate the water resources' carrying capacity in the Deli Watershed, one of the National Strategic River Regions and a raw water supplier for three cities/regencies in North Sumatera Province. The focus is on the quantity of water resources and designing scenarios to address challenges posed by economic and population growth that cause changes in land use. The results indicate that without intervention, the water resources' carrying capacity index declines, reaching a concerning status by 2038; however, integrated programs targeting birth and in-migration rates, domestic water use reduction, and land restoration can lead to a positive trajectory, emphasizing the unique integration of System Dynamics and AHP hold promise for sustainable water resources management practices.