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Testing a Grid‐Based Soil Erosion Model across Topographically Complex Landscapes
Author(s) -
Bonilla Carlos A.,
Norman John M.,
Molling Christine C.,
Karthikeyan K. G.,
Miller Paul S.
Publication year - 2008
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj2007.0310
Subject(s) - environmental science , surface runoff , erosion , storm , hydrology (agriculture) , wepp , growing season , soil science , plough , tillage , agronomy , agriculture , soil conservation , meteorology , geology , geography , ecology , paleontology , geotechnical engineering , archaeology , biology
This study was conducted to evaluate the overall performance of the Precision Agricultural‐Landscape Modeling System (PALMS) for calculating runoff and soil loss under cropped conditions. The PALMS model uses a lognormal distribution of saturated hydraulic conductivity across the fields to simulate typical soil heterogeneity within soil texture classes. Runoff and soil loss data were collected in three farm fields for a total of 75 runoff events during 2 yr under six cropping scenarios (alfalfa [ Medicago sativa L.] and corn [ Zea mays L.] no‐tilled, corn and soybean [ Glycine max (L.) Merr.] moldboard plowed, and alfalfa and corn chisel plowed). For individual storms, calculated runoff and sediment loss from PALMS were compared with corresponding measurements for each farm during the entire cropping season. The coefficient of determination ( r 2 ) between runoff calculations and measurements was 0.84. The r 2 between soil loss calculations and measurements with the storm‐by‐storm simulations during both seasons was 0.78. Based on these continuous simulation results, the PALMS calculations appear to have lower relative errors with large events than small events, a desirable result because large events are most important in assessing the environmental consequences of management practices.