Overland flow erodes sediments from slopes and delivers them to stream valleys. Some precipitation returns to the atmosphere as evaporation. This dominates in arid regions. Intercepted rainwater gradually moves to soil by stemflow and drip. Some precipitation infiltrates the soil surface and becomes soil water or groundwater.
Some precipitation flows overland as sheetwash.
Unconfined to channels. B. Delivery pathways of water to streams The response of streamflow to precipitation events is dramatically influenced by the character of the surrounding drainage basin, especially as it effects the tendency for water to infiltrate into the soil or directly run off as unchannelized overland flow. As sheetwash moves over land, it erodes and transports sediments down slope. Precipitation intensity a. Areas with frequent thunderstorms have high overland flow and low infiltration rates.