Investigating the Impacts of Climate and Land Use Change on the Hydrologic Characteristics in the Sub-Basins of the Dez River, Middle East

Abstract

Human activities and the climate change affects the river flow therefore monitoring flow rate of river for an extended period can reveal the detail of involved mechanisms in these changes. The previous studies show impact of human activities and climate change on river temporal variations varies in different locations. Water scarce is one of most problem in this area therefore finding affected parameters in water accessibility is important for water management in Middle East. This study aimed to investigate the trend of annual and monthly flow changes in the Dez River branches in southwestern Iran by several nonparametric methods. A structural equation model was used to assess the effects of land use and climate changes on river discharge. The study results showed that the annual precipitation at all stations has no significant trend, but temperature and evaporation at most stations increased significantly. Additionally, more than 30% of the study area's rangeland and forestlands have been converted into agricultural and residential lands. The results showed that land use and climate can determine 43.2% of discharge changes. Also, land use changes are more effective than climate change on river discharge changes.

Keywords

• climate change
• discharge
• land use
• non-parametric methods
• structural equation model