ABSTRACT
Rain falling on a virgin land such as forests, grasslands, and wetlands is partly intercepted by vegetation, partly retained by surface depressions and puddles, and partly infiltrates into the ground. Only a small fraction flows overland. Urbanization disturbs land and replaces natural vegetation with impervious surfaces such as roads, driveways, parking areas, and building roofs and compact soils. Thus, it eliminates interception, reduces surface retention, and diminishes infiltration.
