Essay On Infiltration Rate

In soil science, infiltration rate is a measured (inches per hour of millimeters per hour) of the rate at which the water from precipitation or irrigation is able to absorb in the soil. In the other word, infiltration rate is the velocity of water entering the soil. One of the most important factors that affect the process of rainfall-runoff is infiltration rate (Miyata, 2010) which related to the occurrence of Hortonian overland flow (Horton, 1933) where the volume is governed by the difference between infiltration rate and rainfall intensity. Infiltration calculated by using simplified equations such as Horton equation, Philip equation, Green-Amp equation, Richard’s equation, Finite Water-Content Vadose Zone Flow Method, Kostiakov equation and Darcy’s law. Infiltration rate depends on the level of saturation of the soil.

The rate can be determined by using infiltrometer. High precipitation that exceeds the rate of infiltration will cause runoff which associated with the saturated hydraulic conductivity of near-surface soil. Thus, the rate of infiltration is important to be measured especially at the hillslope area which exposed to landslide since runoff can be a part of triggering factor of this hazard. The rate of infiltration of water into the soil depends of soil texture, structure and moisture

Nimmo (2004) stated that the porosity of a soil are depends on packing density, the breadth of the particle size distribution, the shape of particles and cementing. The porosity varies depending on the size and aggregation of the soil particles. Soil porosity is important because it give the soil an ability to provide water and oxygen for plant growth. Tightly packed soils have smaller porosities than loose, porous soil. The total porosity of the soil is the combination of pores of all sizes and