Dynamics and Biogeochemistry of River Corridors and Wetlands (Proceedings of symposium S4 held during the Seventh IAHS Scientific Assembly at Foz do Iguaçu, Brazil, April 2005). IAHS Publ. 294, 2005, 122-129

1 Department of Geography, University of California, Santa Barbara, California 93106, USA

2 Bren School of Environmental Science and Management, University of California, Santa Barbara, California 93106, USA

Abstract This paper presents a methodology to calculate the ponding and infiltration hydrographs in rainfed wetlands with negligible overland drainage. The flooding cycle is made up of at most three phases. In the first, the rainfall rate equals the infiltration rate and there is no ponding. The second phase begins with the initiation of ponding and ends with the end of rainfall or of ponding, whichever comes first. The third, and last, phase starts with the end of rainfall—provided that there is ponded water still extant—and ends with the extinction of ponding. The ponding and infiltration hydrographs are calculated by solving ordinary differential equations of water balance and soil-water flow. Computational examples demonstrate the methodology developed in this work using soils with very different hydraulic properties.

Key words differential equations; infiltration; rainfall; soil moisture; wetlands