Abstract
Purpose Surface hydrology studies are becoming more important for environmentalists and design engineers in arid regions where climate elements, particularly rainfall, are severe, sporadic and difficult to forecast. The main purpose of this study is to analyse elements of surface hydrology in the northwest of Riyadh City as part of environmental quality characterization for urban development. Designmethodologyapproach The study area lies within a typical arid zone in the Arabian desert, and forms an integral part of Riyadh City extension. Field observations, collection and analyses of meteorological data, identification and analyses of the drainage network were the main approaches used in this study. The study made use of SPOT 4 satellite images, published topographic maps and Digital Elevation Model DEM from Shuttle Radar SRTM. Findings Drainage analyses show four subdendritic systems in northwest Riyadh. The study area lies within the middle subcatchment with a total area of 115km2. Average annual rainfall is 125mm. It occurs in the months of NovemberFebruary with a standard deviation of 1725.5 for monthly rainfall and a standard deviation of 3.28.8 for maximum daily rainfall. Annual relative humidity is 34.4 percent, annual solar radiation is 477calcm2 per day, prevailing wind direction is NE and N with an average speed of 5.1kmhr, and average annual evaporation is 2910mm. Runoff peak flow varies from 2.734.67m3sec. Practical implications Planners, design engineers, decision makers can use these findings for urban environmental development. The results of this study can help to prepare safeguard settlements from any unforeseen events. Originalityvalue The study indicates the importance of environmental quality chacterization for urban development.