Evaluation of the Hawizeh Marshes Water Requirements with Respect to Dust Control and Improvement in Environmental Conditions

Hawizeh marshes are located in the southwest of Iran in the drainage basin of Karkheh and Tigris rivers. Human activities in recent years, specifically via construction of several storage and diversion dams upstream of these marshes, have resulted in extreme hydrological and bioenvironmental stresses on the area. In other words, the marshes have lost a large portion of their original surface and have been converted into the greatest locus of haze in the region. Determination of the marshes water requirements may be significantly helpful in the restoration of their ecological conditions and improvement of their bioenvironmental performance. Therefore, marshes water requirements were determined using a comprehensive computational method. In this approach, riparian zone of the beds was determined using hydrological data, geographic information system, and field observations. Then, the normalized difference vegetation index was used to determine water level and vegetation conditions. According to the field observations and reports given by affiliated organizations, reed marshes were the dominant species in the region. Therefore, ecological water requirements of this plant were considered in the computation of water requirements of Hawizeh marshes. Two scenarios were proposed to meet the marshes water requirements. In the first scenario, original conditions of the marshes (before stress) were maintained. In the second scenario, ideal conditions of the northern parts of the marshes (recorded by international organizations) were maintained and the occurrence of haze was prevented in the southern parts. Results showed that the marshes water requirements were 15.6 and 12.4 billion cubic meters under the first and the second scenarios, respectively.