What does wetting front mean?
What does wetting front mean?
As water penetrates a dry soil, the wetted soil takes a darker color in contrast to its original light appearance. The region of rapid change in color resulting from an increased water content is called the wetting front.
What is wetting front suction?
The wetting front suction head describes the attraction of water within the void spaces of the soil column. Like effective porosity, this parameter can also be estimated using surficial soil textures. The wetting front suction head of various soil textures is shown in Table 3.
What is wetting depth?
Depth of wetting is the depth to which water contents have increased due to the introduction of water from external sources, or due to capillarity rise after the elimination of evapo-transpiration.
What is the Green Ampt method?
The basic assumption behind the Green and Ampt equation is that water infiltrates into (relatively) dry soil as a sharp wetting front. The total infiltrated volume between the surface of the soil and the wetting front is defined by equation [7-30]. The infiltration rate f = dF/dt is then given by [7-31].
What is loss method?
The loss rate method defines the equations used in the HMS simulation to separate precipitation volumes from runoff excess. Each of the following methods require one or more input parameters to be defined.
What is wetting zone?
Wetting Zone – In this zone, the water content sharply decreases with depth from the water content of the transmission zone to near the initial water content of the soil. Wetting Front – This zone is characterized by a steep hydraulic gradient and forms a sharp boundary between the wet and dry soil.
What is depth of active zone?
The active zone depth is approximately 0.5 to 4 m depending on the soil properties and climatic conditions. The diffusion coefficient and saturated hydraulic conductivity are the two important parameters controlling the active zone depth.
How do you read hydraulic conductivity?
Values to the right indicate saturated conductivity values. Values to the left indicate unsaturated values. The poorly structured clayey soil (lower line) has a saturated conductivity much lower than the sandy soil. This is because the clayey soil consists of small pores and the flow paths are more restricted.
Which soil has highest hydraulic conductivity?
sandy soil
The soil with the steeper slope (the sandy soil in figure 3) has the higher hydraulic conductivity. Hydraulic conductivity (or slope “K”) defines the proportional relationship between flux and hydraulic gradient, or in this case, of unidirectional flow in saturated soil.
What is ponding time in infiltration?
‘Ponding time’ is the period from the beginning of rainfall until the occurrence of ponding. This model also can compute the variation in the infiltration capacity for constant or variable rainfall rates. A simple conceptual model is valuable for carrying out the stormwater runoff analysis.
What is the initial abstraction?
Initial Abstraction is a parameter that accounts for all losses prior to runoff and consists mainly of interception, infiltration, evaporation, and surface depression storage. In theory all Rainfall minus Initial Abstraction will generate the runoff from a specified Catchment.
