Investigating the Use of Urban Rainfall for Green Space Usage using Civil Storm Software (Case Study: Southern Part of Mashhad City)

One of the main problems in industrial and urban areas is the runoff caused by rainfall and consequently the flood formation in these areas. Two important things in this regard are: i) rainfalls form urban floods, considering the recent droughts, this could be the main water resources for green spaces in urban areas, ii) the major amount of rainfalls become to flood due to the lack of synchronisation with irrigation demand or storage. The aim of this study is to determine the capacity of using rainfall in urban areas for usage in the development of urban green spaces. The runoff volume and runoff hydrograph are calculated using Civil Storm software. Based on the results, a suitable model for calculating the flood volume, as well as economic solutions to build runoff collecting structures are obtained. Civil Storm, Google Earth, Global Mapper, and AutoCad softwares were also used to map channels, nodes, routes, basins, and suburban basins and finally by adding the soil permeability coefficient and rainfall probability, the basin was simulated. The results confirm the ability of Storm Civil software to simulate the surface runoff and design the runoff collection systems. The comparison of the amount of runoff with a return period of 25 years, equal to 269337 m3, with the total volume of water requirement in district 9, equal to 2189849 m3, indicates that the study area, which is approximately one third of the area of district 9, can provide approximately 12.3% of the water requirement of the region.