Technical Report

Bosque Soil Evaporation Monitoring and Modeling Final Report

URL: https://webapps.usgs.gov/mrgescp/documents/Stormont%20et%20al_2007_Bosque%20Soil%20Evaporation%20Monitoring%20and%20Modeling%20Final%20Report.pdf

Date: 2007/07/11

Author(s): Stormont J., Coonrod J., Farfan E., Isaacson K., Smith L.

Publication: Unversity of New Mexico Report, 61 p.

Abstract:

Evapotranspiration (ET) can be a very significant depletion of water within the Middle Rio Grande corridor. ET includes water consumed by vegetation as well as that evaporated from soil. Attention has been focused on ET depletions from non-native species that have invaded the Middle Rio Grande corridor, notably salt cedar and Russian olive. However, soil water evaporation can be significant, especially in the presence of a shallow water table, and cannot be ignored as an ET component.

Habitat and bosque restoration strategies may include the removal of non-native species. Removal of vegetation can open the ground to more sun and wind, and consequently increase soil water evaporation. Other potential restoration activities include over-banking and creating wetlands, which will increase the near-surface soil moisture content, locally raising the groundwater table and increasing soil water evaporation. Thus, there is a need to understand the magnitude and controls on soil water evaporation as it relates to restoration activities.

Soil water evaporation is maximized if there is a shallow groundwater table, a hot and dry climate, a bare surface exposed to sunlight and wind, and a uniform fine-grained soil. Perhaps the most important factor in the amount of soil water evaporation is the proximity of the water table. If the water table is very shallow (within a meter or so), water will be continually supplied from the water table upward to the soil surface. This type of evaporation is often termed water table evaporation. In this case, soil evaporation will be controlled largely by climatic conditions at the soil surface. For example, an increasing amount of shade will greatly reduce the amount of soil evaporation in the presence of a shallow water table.