Sediment accumulation expectations for growing desert cities: a realistic desired outcome to be used in constructing appropriately sized sediment storage of flood control structures

Abstract

Many rapidly urbanizing desert cities (RUDC) around the globe experience an acute risk of flooding. To reduce this risk, properly engineered flood control structures (FCS) must account for sediment accumulation as well as flood waters. While the Phoenix area, USA, uses regional data from non-urban, non-desert watersheds to generate sediment yield rates, the proposed desired outcome for RUDCs is to base FCS on data related to urbanization. Wolman (1967 Geogr. Ann. A 49 385–95) recognized that sediment yields spike during a relatively short period of bare-ground exposure associated with urban growth, followed by surface sealing resulting in a great reduction in sediment yield. This research presents a new analysis of empirical data where two regression models provide estimates of a more realistic sediment accumulation for arid regions and also urbanization of a desert cities: (i) linear regression between drainage area and sediment yield based on a compilation of more than 150 global sediment yield data for warm desert (BWh Köppen‐Geiger) climate; and (ii) linear regression relating percent urban growth with sediment yield using available data on urbanization-generated sediment associated with growth of a desert city. The new model can be used to predict the realistic sediment accumulation for helping provide data where few data exists in urbanizing parts of arid Africa, southwest Asia, and India.

Keywords

• reservoir sedimentation
• flood control structure
• sediment yield
• rapidly urbanizing desert cities