Evaluation of three environmental flow techniques in Shoor wetland of Golpayegan, Iran

Shoor wetland, in south central Iran, is a unique ecosystem which plays an important role in maintaining stability of this eco-region. The most important function of Shoor is dust control. Environmental flow releases are a tool for wetland restoration, but their success has not been consistent. We utilized Justin (Watershed), Flow Duration Curve (FDC), and Water Resources Balance (WRB) methods to determine optimal environmental flow for Shoor wetland, which can help in its preservation. Data pertaining to Golpayegan River flow, reported by Chamesfand Hydrometric Station between 1985 and 2017 were used for FDC analysis. FDC results say that 60% of flow frequency occurrence in to Shoor is < 2 m³/s, and 20% is > 5 m³/s. Water resource balance analysis indicates that between May and November, environmental flow to Shoor is negative, and the wetland is in desiccation mode. Suggesting that, at this time, surface water charges are essential for health of the wetland. The average monthly environmental flow rate (l/s) for each method are as follows: Justin (1282), FDC (1397.5), and WRB (5373). Environmental flow assessed by WRB is the highest. To protect health of Shoor and prevent further degradation of this wetland, we recommend shutting down agricultural drains. This action will safeguard appropriate groundwater levels and protect areas of Shoor that are prone to dust creation. Better well water management will also help restore Shoor ecosystem. We highly recommend these measures.