What is a variable water source?
Variable Source Area Hydrology is the concept that the majority of runoff exiting a watershed is driven by a relatively small portion of the watershed. The abundance of these runoff generating sources may increase and decrease depending on temporal and spatial variability.
What is variable source concept?
Variable Source Area (VSA) Hydrology is the concept that runoff-generating areas in the landscape will vary in location and size over time.
What are variable source areas in relation to flow generation?
Abstract. The variable source area concept of streamflow and storm-flow generation proposes that the area of land yielding surface water to streamflow varies with time and that, for vegetated basins, subsurface flow not only sustains baseflow but is also a major component of storm flow.
What is variable hydrology?
The hydrological variables investigated are average annual rainfall (P), precipitation concentration degree (PCD), antecedent dry weather period (ADWP), and ratio of dry days to rainy days (nD/nR). With the exception of P, all other variables represent the temporal variability of precipitation.
What is saturated overland flow?
when the combination of precipitation intensity and duration (and run-on from higher areas) saturates the soil and raises the water table to the surface. This process is known as saturation overland flow.
What is the definition of throughflow in geography?
Beneath the surface, water is transferred via throughflow, which is the movement of water through the lower soil towards rivers, and groundwater flow. Groundwater flow is typically very slow.
What is the Horton model?
The Horton method describes how infiltration capacity declines as the precipitation event advances and is based on generating runoff when rainfall intensity exceeds the infiltration capacity. In addition, the modified Horton’s equation describes the recovery of infiltration capacity during dry periods.
What is overland flow by running water?
Overland flow is defined as water that flows over the land surface as either diffuse sheet flow (laminar or mixed laminar flow) or concentrated flow (turbulent flow) in rills and gullies (Ward and Robinson, 2000).
What is the difference between Hortonian and saturation overland flow?
when the intensity of precipitation that reaches the surface exceeds the infiltration capacity of the soil. This process is known as Hortonian overland flow. 2. when the combination of precipitation intensity and duration (and run-on from higher areas) saturates the soil and raises the water table to the surface.
What is variable source area hydrology?
Variable Source Area (VSA) Hydrology is the concept that runoff-generating areas in the landscape will vary in location and size over time. The VSAs are not static, they will increase and decrease in size and appear in various locations depending on time of year, rainfall, temperature, topology, and vegetation among other factors.
What is source water?
What Is Source Water? Source water refers to sources of water (such as rivers, streams, lakes, reservoirs, springs, and groundwater) that provide water to public drinking water supplies and private wells.
What is source water protection?
Source water protection includes a wide variety of actions and activities aimed at safeguarding, maintaining, or improving the quality and/or quantity of sources of drinking water and their contributing areas. These activities may depend on the type of source being protected (e.g., groundwater, reservoir, or river).
When is a source under the direct influence of surface water?
When these shifts can be closely correlated with rainfall, breakup, or other surface water conditions or when certain indicator organisms associated with surface water are found, the source is said to be under the direct influence of surface water.