Theses and Dissertations at Montana State University (MSU)
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Item The development of an erosion test to determine the relative erodibility of fine grained forest soils(Montana State University - Bozeman, College of Engineering, 1964) Hogan, James DennisItem Radiocesium in Montana soils and applications for soil erosion measurement(Montana State University - Bozeman, College of Agriculture, 1984) Arnalds, Olafur Gestur; Chairperson, Graduate Committee: Gerald A. NielsenRadiocesium levels in soils were measured at eleven sites throughout Montana. Cesium was mostly confined to the top of the soil profile. Both lateral and vertical displacement of cesium was attributed to mechanical movement of soil particles. The areal activity of cesium was strongly correlated to annual precipitation (R^2 = 0.92). An equation is given to predict cesium activity from annual rainfall. Methods of calculating soil erosion and deposition are discussed and performed for a wind erosion study site in Pondera County and a small watershed in Teton County. The results indicate that deposition at the wind erosion study site can be quantified. Soil deposition of 70 to 1290 m^3 ha^-1 was measured on the leeward sides of a fence and tree windbreaks while an average of 450 m^3 was lost from the windward sides. An average of 740 m^3 ha^-1 was lost since 1962 from an adjacent wind eroded field. This amounts to 34.8 Mg ha^-1 yr^-1. Soil loss since about 1962 ranged from 300 to 820 m^3 ha^-1 within the upper areas of the watershed studied. A pond at the outlet of the watershed and deposition areas at the toeslope accounted for a relatively small fraction of the soil loss within the watershed. Most of the losses are likely to be from wind erosion. Length of slopes or position within the field were more related to erosion than was steepness of slopes, Estimates of erosion rates based on 137Cs ranged from 16.5 Mg ha^-1 yr^-1 at the summit of the watershed to 45.1 Mg ha^-1 yr^-1 at the midslope. Predictions by conventional methods (wind erosion equation and the Universal Soil Loss Equation) agreed rather closely with the estimates from 137Cs.Item Modeling soil productivity in Montana using a Geographic Information System and existing data bases(Montana State University - Bozeman, College of Letters & Science, 1998) Langner, UteItem Soil erodibility prediction for excavated materials(Montana State University - Bozeman, College of Engineering, 1988) Hartsog, William S.Item Spatial variability of soil redistribution processes in a small agricultural watershed(Montana State University - Bozeman, College of Letters & Science, 1990) Pings, John CorneliusItem Erosional impact of hikers, horses, off-road bicycles, and motorcycles on mountain trails(Montana State University - Bozeman, College of Letters & Science, 1991) Seney, Joseph PaulItem Physiographic components of trail erosion(Montana State University - Bozeman, College of Letters & Science, 2000) Godwin, Ian Chandler Paterson; Chairperson, Graduate Committee: Andrew MarcusNo previous study has sought to discriminate between soil erosion and soil compaction when explaining the "missing" cross-sectional areas of incised trails, assuming instead that erosion was the dominant process. Separating the two processes of erosion and compaction is critical to understanding the relationship between physiographic variables and the structure of trails. The purposes of this project are to estimate the relative effects of compaction and erosion on trail cross sectional area along the New World Gulch Trail, Montana, and to better understand the relationship between erosion, compaction, local topography, vegetation, soil bulk density, and soil texture. The following hypotheses were addressed: 1) adjusting the incised cross sectional area of a trail, by removing the effects of soil compaction, will increase the amount of variance in erosion explained by collected physiographic variables; and 2) inclusion of soil bulk density and soil texture as physiographic variables will increase the amount of variance in cross-sectional area explained along the trail. The goals of this study required the collection of field data, analysis of soil samples, and statistical analysis of data. Soil samples and other field measurements were collected over several months during the summer and fall of 1994. Some of the topographic information used in the statistical analysis originated in Urie's (1994) study of recreational trails. The determination of trail slope as one of the primary components of trail incision is consistent with previous studies. Soil water content is the second most significant independent variable when the percentage of particle sizes are not considered. Percent vegetative cover is also significant in the stepwise regression, although it is not significantly correlated to cross-sectional area. The most significant variable added to those already studied was soil bulk density. When individual variables were regressed against the measured cross-sectional area, off-trail soil bulk density accounted for the second greatest amount of variance (r2 = 0.12) after trail slope (r2 = 0.35). The ratio of on-trail soil bulk density to off-trail soil bulk density, which could be considered a measure of compaction, accounted for even more variance (r2 = 0.18) than soil bulk density.