Infiltrationskapacitet

Infiltrationskapacitet is the maximum rate at which water can infiltrate the soil surface under specified conditions. It depends on soil properties such as texture, structure, porosity and hydraulic conductivity, as well as surface characteristics like roughness, crust formation, vegetation cover and organic matter. Antecedent soil moisture also plays a crucial role. Infiltrationskapacitet is not fixed; it is a dynamic parameter that changes during infiltration.

During a rainfall event, the infiltration capacity often decreases over time as the soil wets and a surface seal or crust may form, reducing the rate at which water can enter the soil. If rainfall intensity exceeds the current infiltration capacity, water will begin to runoff on the surface. If rainfall is lighter or soil conditions allow, infiltration may keep pace with the rainfall, resulting in little or no surface runoff. The concept is used to distinguish infiltration-excess runoff from saturation-excess runoff.

Measurement and modeling of infiltrationskapacitet typically involve field tests and numerical methods. Field methods include infiltrometers (such as double-ring or single-ring devices) and rainfall simulators to estimate infiltration rates. Infiltration capacity is also described by models that express instantaneous infiltration rate f(t) or cumulative infiltration F(t), such as Green–Ampt, Horton, or Kostiakov approaches. These models require parameters related to soil hydraulic properties and moisture conditions.

Applications of infiltrationskapacitet span hydrology, urban drainage design, agriculture and erosion assessment. Knowledge of infiltration capacity helps predict runoff, plan drainage and irrigation, and evaluate the effects of land cover, soil management and seasonal changes on groundwater recharge and surface water quality.