Socio-hydrology modeling with changing community preferences in the Tashk-Bakhtegan Basin

This study focuses on developing a conceptual socio-hydrologic model to simulate community response and hydrology interactions in the Tashk and Bakhtegan lakes basin. There is a sharp decline in lake water levels due to agricultural development in upstream areas of Tashk and Bakhtegan lakes, along with droughts that occurred in the 2000s. This study demonstrates the potential of socio-hydrology modeling to describe complex human-water systems applying simple concepts and relationships. For the sociological module, two variables of community sensitivity and behavioral response have been chosen. For the hydrological module, the developed water balance model for dry catchments has been used. It is assumed that changes can be different in human priorities and community sensitivities in the upstream and downstream residents of the basin due to the basin extent and the differences in the region. The time period of the study is between 1996 and 2013. The results showed that the perceived level of threat to a community’s quality of life is low in the upstream sub-region of the basin, which has more rainfall and water resources. As a result, the preferences of its residents are toward using more water and land resources. But in the downstream sub-region of the basin, people have shifted their preferences for using less water and land resources, especially with environmental problems and scarcity of water resources causing a high level of threat to their quality of life.