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Accounting for the influence of runoff on event soil erodibilities associated with the EI 30 index in RUSLE2
Author(s) -
Kinnell P. I. A.
Publication year - 2014
Publication title -
hydrological processes
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.222
H-Index - 161
eISSN - 1099-1085
pISSN - 0885-6087
DOI - 10.1002/hyp.10271
Subject(s) - surface runoff , universal soil loss equation , environmental science , storm , hydrology (agriculture) , precipitation , erosion , soil water , soil loss , index (typography) , water content , soil science , mathematics , geography , meteorology , geology , ecology , paleontology , geotechnical engineering , biology , world wide web , computer science
Soil erodibilities ( K ) associated with the EI 30 index vary not only with soil properties but also with soil moisture as it varies in time and space. In Revised Universal Soil Loss Equation Version 2 (RUSLE2), temporal variations in soil erodibility in the USA are calculated using monthly precipitation and temperature as independent variables. K UM , the soil erodibility factor associated with the Q R EI 30 index, varies independently of runoff and the product of K UM and the runoff ratio for the unit plot ( Q R1 ) provides an alternative to the temporally varying K s currently used in predicting storm soil loss in RUSLE2. Comparisons were made between the product of Q R1 and K UM and RUSLE2 K s for representative storms at four locations representing the north to south variation in climate in the USA. Peak erosion associated with the current approach used in RUSLE2 was slightly higher at two locations and slightly lower at the other two locations. One other location, Morris, MN, provided an exception with the peak loss predicted by using the product of Q R1 and K UM being 1.7 times that obtained using RUSLE2 K s. In theory, average annual K UM values should be better related to soil properties than the average annual values of K frequently used when the average annual values of EI 30 are used to predict soil loss. However, work has yet to be performed to determine how K UM varies directly with soil properties and in space and time. Copyright © 2014 John Wiley & Sons, Ltd.