- Lower discharge and less frequent flow: Due to lower precipitation and higher evapotranspiration rates in arid and semi-arid regions, ephemeral streams have lower discharge compared to those in humid locations. They experience extended periods of no or very low flow, often lasting for several months or even years.
- Flash floods and sediment transport: Arid and semi-arid regions are prone to intense rainfall events, which can generate sudden and powerful flash floods. These floods can rapidly transport large amounts of sediment, boulders, and debris, shaping the geomorphology of ephemeral stream channels.
- Vegetation influence: Vegetation plays a crucial role in ephemeral streams of arid and semi-arid regions. The presence of vegetation helps stabilize streambanks, reduce erosion, and improve water infiltration, thereby influencing the hydrology and geomorphology of these streams.
- Groundwater interaction: Ephemeral streams in arid and semi-arid locations often have a strong interaction with groundwater. During periods of flow, these streams may recharge groundwater aquifers, while during dry periods, groundwater can discharge into the streambed, sustaining base flow.
- Ecological significance: Ephemeral streams in arid and semi-arid regions provide important habitats for various plants and animals adapted to these harsh environments. Many species rely on these streams for water, food, and shelter during the brief periods when they are flowing.
In contrast, ephemeral streams in humid locations:
- More frequent flow: Ephemeral streams in humid regions experience more frequent flow due to higher precipitation and lower evapotranspiration rates. These streams may flow for several weeks or months each year, but they still have periods of no or low flow.
- Less pronounced flash floods: Flash floods can occur in humid regions, but they are generally less frequent and less intense compared to arid and semi-arid areas. The higher vegetation cover and more moderate rainfall events help mitigate the impact of flash floods.
- Reduced sediment transport: Ephemeral streams in humid locations typically transport less sediment compared to those in arid and semi-arid regions. The denser vegetation and lower erosive power of water in humid environments contribute to reduced sediment transport.
- Groundwater interaction: Ephemeral streams in humid regions can interact with groundwater, but the interaction is generally less significant compared to arid and semi-arid locations. Groundwater recharge and discharge may occur, but the streams are less dependent on groundwater for sustaining base flow.
- Ecological significance: Ephemeral streams in humid regions also provide important habitats for a variety of plants and animals, but the species composition and ecological functions may differ from those in arid and semi-arid environments.
