Hydrologic and edaphic patterns and processes leading to playa flooding

TitleHydrologic and edaphic patterns and processes leading to playa flooding
Publication TypeThesis
Year of Publication1989
AuthorsVan Vactor SScott
Number of Pages91
Date Published1989
UniversityNew Mexico State University
CityLas Cruces, New Mexico
Thesis TypeM.S. Thesispp
Accession NumberJRN00098
Call Number00345
Keywordsdissertation, dissertations, flooding,playa, hydrology, playa flooding, model, playa flooding, playa, flooding, theses, thesis, transect, playa flooding
AbstractA conceptual model of the hydrologic patterns and processes leading to the flooding of College Playa was developed. College Playa is a small, freshwater, desert playa located on the Jornada Long Term Ecological Research site and the New Mexico State University College Ranch. This model was based on an 18-year record of flooding of College Playa and the rainfall occurring on its watershed. College Playa's watersheds soils and major landforms were also considered in the model development. Several essential features of the model are that (1) College Playa may flood due to as little as 25 mm of rainfall if there is a 0.5 hr period with an intensity of 25mm/hr at some time during the storm, but (2) the rainfall must occur at or near the playa basin, and (3) runoff from the upland areas of the watershed's fan piedmont is not necessary for the playa to flood. The arrangement of playa basin soils is consistent with the observed high frequency of only partial flooding of the playa basin. The proposed conceptual model was examined using MULTSED, a mathematical, watershed level, physically based, rainfall-runoff event model. The essential features of the conceptual model were preserved in the mathematical model. The conceptual model may be applicable, at least qualitatively, to many other playas. However, the rainfall and flooding records necessary to investigate the applicability of the model to other playas are not available. Following from the proposed conceptual model, sediment and detritus sources in and near the playa basin have greater influence on playa water chemistry, and consequently on playa aquatic community structure and dynamics, than more distant, upland sediment and detritus sources.