Click on “Download PDF” for the PDF version or on the title for the HTML version.


If you are not an ASABE member or if your employer has not arranged for access to the full-text, Click here for options.

Estimating Effective Hydraulic  Conductivity (Ke) for the Rangeland  Hydrology and Erosion Model (RHEM)

Published by the American Society of Agricultural and Biological Engineers, St. Joseph, Michigan www.asabe.org

Citation:  Journal of the ASABE. 67(1): 141-149. (doi: 10.13031/ja.15652) @2024
Authors:   Osama Zuhair Al-hamdan, C. Jason Williams, Fred B. Pierson, Mariano Hernandez, S. Kossi Nouwakpo
Keywords:   Disturbed Rangelands, Hillslope Runoff, Infiltration.

Highlights

Effective hydraulic conductivity (Ke) predictive equations in all RHEM versions have satisfactory performance.

New Ke predictive equations were developed for RHEM applications over broader rangeland conditions.

Ke values on most rangelands can be estimated through readily measurable ground cover and soil texture data.

Abstract. Effective hydraulic conductivity (Ke) is an important parameter for the prediction of infiltration and runoff by the Rangeland Hydrology and Erosion Model (RHEM). Three sets of equations to predict Ke have previously been used in RHEM. These equations are mainly based on rainfall simulation data representing undisturbed sites and have not undergone comprehensive evaluation for various rangeland conditions, particularly after disturbances. The goal of this research was to evaluate these equations using independent data obtained from rainfall simulations conducted at multiple rangeland sites. Additionally, we developed and evaluated a new set of Ke predictive equations applying readily measurable cover and soils data spanning a wide range of vegetation, soil textures, and disturbance conditions. The results show that all previous Ke equations in RHEM have a “satisfactory” performance with index of agreement (d) > 0.75 and R2 > 0.4. The new Ke approach resulted in “very good” performance with d > 0.9 and R2 > 0.5. The new set of equations enhances RHEM for applications over broader rangeland conditions, including sparse vegetation cover following disturbances or community transitions.

(Download PDF)    (Export to EndNotes)