Submitted to: ARS Workshop on Real World Infiltration
Publication Type: Proceedings
Publication Acceptance Date: 9/30/1996
Publication Date: N/A
Interpretive Summary: Seasonally frozen soil plays an important role in the hydrology in northern latitudes. In many areas, rain or snowmelt on seasonally frozen soil is the single leading cause of severe flooding and erosion, but most hydrologic models do not address the effects of soil freezing on infiltration. Efforts to predict frozen soil infiltration and runoff have had limited success, which is reflective of the current knowledge of frozen soil infiltration processes. Frozen soil processes lag considerably behind non-frozen processes due partly to the difficulty in quantifying and measuring water and ice conditions in frozen soil. An array of modeling approaches for describing infiltration into frozen soils is presented, and future directions for modeling infiltration into frozen soil is discussed. Incorporation of these modeling approaches into existing computer models of runoff and erosion promises better evaluation of flooding potential from seasonally frozen soils.
Technical Abstract: The occurrence of frozen soil can result in significant runoff and erosion events from otherwise mild rainfall or snowmelt events. However most hydrologic models, including most snowmelt runoff models, include no provisions for soil freezing and thawing, and thus cannot address these extreme, yet common hydrologic events. A wide array of approaches exist among different models for compensating for the effects of frozen soil on infiltration. The purpose of this paper is to present the state-of-the-sci in modeling frozen soil infiltration and to propose future research directions to improve our prediction of infiltration into frozen soils. Future research needs include: better quantification of the interrelation between water content, ice content, and texture; better quantification of the effects that these have on infiltration; and development of a methodology for accounting for which pores are filled with ice and which are available for infiltration.