A WebGIS-based flood control management system for small reservoirs: a case study in the lower reaches of the Yangtze River

Small reservoirs are important to flood control and water resource utilization in local areas. This study proposes a WebGIS-based flood control management system to support the flood discharge of small reservoirs during intensive rainfall in the flood season. The agile software development method and a loosely coupled structure are used to combine multidisciplinary knowledge from different experts. A flood level forecasting model for reservoirs in humid regions is established based on rainfall and water level measurements. It aims to provide concise information for reservoir managers to choose an appropriate discharging scheme, so that the capacity is maintained in a safe range on the next day. Using the Hengshan Reservoir in the lower reaches of the Yangtze River as an example, the model verification reveals that it is acceptable for rainfall events whose daily amount is near or above 100 mm (the heavy rainstorm level in China), and the system is verified by a trial operation during the typhoon season. While most existing flood control systems focus on river basins and large reservoirs, this study considers the data availability and practical flood discharging scenario of small reservoirs, and provides a useful tool for flood control management.