Simulation and Evaluation of River Habitat Suitability Using SEFA Ecohydraulic Model (Case Study:Kordan River)

The main objective of this study is to investigate habitat suitability in a representative reach of the Kordan River for aquatic species (Oxynoemacheilus bergianus) using the SEFA ecohydraulic model. According to a study conducted so far, this software has not been used in Iran. First, using the topographic map of the Kordan River and ArcGIS software, the geometry of the river model and cross sections was created. Hydraulic calculations and simulations in this model including simulation of water levels were conducted using two methods of rating curve and Water Surface Profile (WSP). The calibration of the WSP model is adjusted by the Manning''s coefficient to establish a suitable fit between the observed and calculated water levels. In addition to hydraulic simulations in the SEFA model, the relationship between hydraulic flow and habitat requirements was established using the Area-Weighted Suitability (AWS) and Q-AWS curves of target species were extracted at the studied intervals and transverse sections. the best flow assessed (2.05 – 2.63 m3/s) for target species were identified. According to the flow and AWS monthly time series, in January the AWS in 75% of the days is above 2.03 m2/m which is the highest AWS comparing to the other months. The lowest percentage of AWS is 13% (in September). The results showed that AWS is higher in the middle and downstream reaches of the river.