Conservation agriculture has many potential benefits for small farmers. This study seeks to estimate the value that farmers in eastern Uganda place on some these benefits. Data from a choice experiment study are analyzed with a mixed logit model to determine farmers' willingness to pay for increases in maize yield, reductions in erosion, and reductions in land preparation labor requirements. It finds that farmers have a statistically significant willingness to pay for increases in yield and reductions in erosion, but not for reductions in planting labor. In addition, farmers in Kapchorwa district value erosion control and labor reductions more and price increases less than in Tororo district, while women care more about price increases than men do. / Master of Science / CCRA-6 (Economic and Impact Analysis)

This research analyzes private and social costs of forest conservation in Yaque del Norte watershed, DR. It calculates private costs as average annual income from farming activities and social costs as the externalities from erosion and CO2 emissions. Social cost estimates are based on the difference in erosion and CO2 between conserved forest and other land use categories. The effect of soil erosion on the wellbeing of people is measured by its effect on reduced space at Tavera dam for water availability to generate electricity and to irrigate agricultural lands downstream. The social cost of increased annual carbon emission from potential land use change is estimated using IPCC default emission factors and social cost of carbon estimates. Private costs are inferred from a nonlinear binary response model that estimates the relative importance of factors affecting forest conservation decisions of households. Results show that payment level, measured through rental value, is not significant for landholders' decisions to sign a PES contract. Annual cropland is the most profitable land use in the area. Other important, but less profitable, land covers are pasture, coffee and managed forest. Cropland also generates the highest cost for society in terms of erosion and CO2 emissions. The comparison of private and social costs shows that only livestock generates a social cost that exceeds average private income. If forest conservation were to be justified based on social benefits, the analysis must include a more comprehensive assessment of what people value from conserved forest in YNW, such as the effect of erosion for water treatment costs. Any proposal to retain forests social benefits, such as REDD+ initiative, should take into account the high cost forgone by forest owners when deciding the distribution of benefits of carbon sequestration. / Master of Science / Environmental services generate benefits for both private and public entities, which increases the complexity of calculating optimal levels for payment for environmental services (PES). A pilot PES project in the Yaque del Norte watershed of the Dominican Republic is an excellent example of this complexity; with benefits from upland forest conservation accruing to a hydroelectric company, a water supply company, and society at large. Reducing soil erosion through forest conservation can preserve dam capacity for hydro-electric power generation, preserve water quality and lower treatment costs, and reduce the global economic costs of CO₂ emissions. This study evaluates the socio-economic costs of forestland conservation in the Yaque del Norte catchment. The social benefits of carbon stored under forest land are compared to benefits under alternative land uses. In addition, forest land benefits from erosion prevention are estimated using a Universal Soil Loss Equation. Calculated benefits from forestland conservation are then compared to landuse opportunity cost estimates generated through a farm-level survey in the area. Study results show that the opportunity cost of forest conservation in the Yaque del Norte is high; ranging from between RD$10,000 and RD$200,000 per hectare per year. If society values carbon and soil retention as the direct benefits drawn from conserved forest, only lands with low very opportunity costs will be conserved. However, inclusion of the indirect external benefits of forestland conversion suggests that in many cases forest conservation generates greater social benefits than the private benefits associated with alternative land uses from conversion. PES payment levels of RD$5,000/ha/yr that internalize these external social benefits to forest land holders appear to be sufficient to preserve a significant share of current land and generate net social benefits. Further, part of the costs of these PES payments can be borne by hydro-electric and water companies, as they benefit directly from forest land conservation.

The erosion process was characterized on two small agricultural watersheds in Piedmont Virginia. Rainfall and runoff were measured for all storms at both watersheds over a two year monitoring period. Although the data base was relatively short, the data covered a wide range of rainfall and runoff conditions. Runoff samples were collected, analyzed, and used to compute loading rates of sediment, nitrate N, ammonium N, TKN, orthophosphate P, and total P on an event basis. Yields from missed storms were estimated from log-log linear least squares regression rating curves. Seasonal and annual totals of loading rates were computed by summing the yields for all storms. Existing estimation techniques were used to calculate rainfall energy, rainfall energy contributing to rainfall, the runoff/rainfall ratio, gross erosion and delivery ratios. USLE C-factors for each field were evaluated for changes in crop and cover conditions. Enrichment ratios for available P, nitrate N, and TKN were estimated on an annual basis. Clay enrichment and particle size distributions of the surface soil and the sediment in runoff from each watershed were also determined. These erosion characteristics were contrasted between the two watersheds whose land management practices differed. A comparison between years was also made on the conservation watershed, where part of the conservation plan was abandoned the second year. The use of conservation practices resulted in smaller estimates of gross erosion, smaller sediment and sediment-bound nutrient yields, and less runoff. / M.S.

Digital satellite remote sensing and Geographic Information Systems (GIS) have been used effectively to determine the Universal Soil Loss Equation (USLE) output for a number of North Texas watersheds. This method involves determining the values of each of the USLE factors and using these factors as information layers within the GIS.

Best Management Practices (BMPs) are conservation practices designed by Natural Resource Conservation Service to help mitigate erosion and nutrient losses in agriculture. Water and Sediment Control Basins (WASCoBs) are BMPs implemented in agriculture fields with sloping topography that are susceptible to erosion to help reduce sediment and nutrient losses. There is little research examining the water quality impacts of WASCoBs and their ability to decrease nutrients in water runoff. Runoff samples were collected following intense rain events in seven basins and analyzed for total suspended soils (TSS), total phosphorus, dissolved reactive phosphorus (DRP), ammonium-nitrogen, and nitrate-nitrogen. Nutrient and sediment concentrations and discharge measurements were used to determine event loads for each basin. The WASCoBs trapped an average of 63.4% of TSS, 30.5% of total phosphorus, 15.3% of DRP, 21.8% of ammonium-nitrogen, and 62.9% of nitrate-nitrogen. An Unmanned Aerial Vehicle (UAV) was used to estimate sedimentation rates and proved to be less effective for annual sediment estimates, but perhaps more accurate on a multi-year basis. A detailed soil assessment was performed on all thirty-two basins to estimate short-term legacy phosphorus accumulation. The thirty-two basins trapped an average of 5,403.0 kg/ha of sediment and 16.8 kg/ha of phosphorus. An average of 22 mg kg-1 of total phosphorus accumulated across the basins in one year of sediment accumulation. Potential crop yield penalty was investigated to see the impact between inside the basins compared to the surrounding area. Corn had a decrease of 5.1% yield and soybeans had a decrease of 36.9% in yield inside the basins.

Thesis (Ph. D.)--Oregon State University, 2008. / Printout. Includes bibliographical references. Also available on the World Wide Web.

The thesis is focused on the evaluation of erosion risks and design solutions to selected comprehensive landscaping project. As a region of interest for the job is selected cadastral areas Rychnov u Nových Hradů and Dlouhá Stropnice, which lies in Region of South Budweis. For calculations of values is washed off using a universal soil loss equation by Wischmeier and Smith. The plots of erosion rate greater than the permissible quantity of proposed erosion control measures such as erosion control crop rotation, contour cultivation and erosion limits.

MENVSC (Geography) / Department of Geography and Geo-Information Sciences / Environmental degradation is a quite familiar factor of the mining industry that has been associated with South African mining industry from the beginning. The decommissioning of abandoned mines before the environment legislation, The National Environmental Management Act 107 of 1998 and the Minerals and Petroleum Resources Development Act 23 of 2002, was introduced is of great concern as the abandonment of mines without appropriate remediation and pollution monitoring was the result. Soil erosion has been recognised as an environmental hazard that emanates from abandoned mines. This study seeks to assess the soil erosion hazard around Nyala abandoned mine. The modified method of Soil Loss Estimation Model for Southern Africa (SLEMSA), for assessing soil erosion hazard, was used to estimate the spatial variation of erosion to achieve the goal of the study. Parameters that were considered for the model include relief (Slope steepness, S & slope length, L), soil erodibility (Fb), vegetation cover (C) and rainfall erosivity (E). Soil samples were collected from the field and; sieve and hydrometer analysis was conducted to determine the erodibility factor value of the study area. The model was run in a GIS environment (ArcGIS) and the parameters were multiplied to generate a soil erosion hazard map for the abandoned Nyala mine area. Results from the study indicated that 74.3 % of the watershed experiences low to moderate erosion hazard, with an estimated annual soil loss of 2.76 tons/ha/yr. The low rates of soil erosion in most parts of the watershed are associated with the low topographic ratio and low rainfall erosivity. The research demonstrated that the modified SLEMSA model used within GIS is a very useful tool as it enhances the capacity to assess and model the spatial variation of soil erosion hazard in a timeously and affordable manner. / NRF

by Leung, Yu-fai. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1992. / Includes bibliographical references (leaves 167-178). / abstract --- p.ii / acknowledgements --- p.iv / table of contents --- p.vi / list of tables --- p.ix / list of figures --- p.xi / list of plates --- p.xiii / Chapter CHAPTER I --- introduction / the problem --- p.1 / The Country Parks of Hong Kong --- p.1 / Resource Impacts of Country-Park Recreation --- p.3 / Trail Degradation --- p.4 / objectives of the study --- p.5 / scope of the study --- p.6 / Chapter CHAPTER II --- literature review / introduction --- p.8 / research approaches --- p.9 / physical degradation on trails --- p.11 / Compaction / Widening and Incision / Erosion --- p.16 / FACTORS CONTRIBUTING TO TRAIL DEGRADATION --- p.17 / Use Characteristics --- p.19 / Environment --- p.20 / RECREATION IMPACT STUDIES IN HONG KONG --- p.21 / Chapter CHAPTER III --- study area / introduction --- p.24 / the pat sin leng country park --- p.24 / "Topography,Geology and Soils" --- p.25 / Climate and Vegetation --- p.29 / Recreational Use and Management --- p.31 / the pat sin range trail --- p.35 / Chapter CHAPTER IV --- research methodology / introduction --- p.41 / research design --- p.41 / hypotheses --- p.43 / SAMPLING SCHEME --- p.44 / VARIABLES INCLUDED IN THE STUDY --- p.46 / FIELD MEASUREMENTS --- p.49 / Degradation-Indicator Variables --- p.49 / Site Condition Variables --- p.58 / LABORATORY ANALYSIS --- p.63 / DATA MANIPULATION AND ANALYSIS --- p.65 / Chapter CHAPTER V --- SITE AND DEGRADATION CONDITION OF THE PAT SIN RANGE TRAIL / INTRODUCTION --- p.67 / SITE CONDITION OF THE TRAIL --- p.67 / Parent Material --- p.67 / Topography --- p.72 / TREAD SURFACE MATERIAL --- p.80 / COMPACTION OF TRAIL TREAD --- p.82 / MORPHOLOGY OF TRAIL TREAD --- p.90 / Tread width --- p.91 / Incision Depth --- p.94 / Tread Cross-Section Area --- p.96 / Multiple Treads --- p.96 / Other Morphology Variables --- p.98 / OVERALL EVALUATION --- p.98 / Other Evidence of Degradation --- p.98 / Summary Rating --- p.101 / REMARKS --- p.106 / Chapter CHAPTER VI --- ENVIRONMENTAL INFLUENCES ON TRAIL DEGRDATION / INTRODUCTION --- p.107 / BRANCHING EFFECT OF TRAILS --- p.108 / PARENT MATERIAL --- p.112 / Parent Rock --- p.112 / Soil Properties --- p.115 / LOCATIONAL FACTORS --- p.120 / Aspect --- p.120 / Slope Steepness --- p.124 / Trail Position on Slope --- p.136 / OVERALL EVALUATION --- p.145 / Chapter CHAPTER VII --- MANAGEMENT IMPLICATIONS / INTRODUCTION --- p.151 / MANAGEMENT CONSIDERATIONS --- p.152 / THE CASE OF PAT SIN RANGE TRAIL --- p.153 / MONITORING TRAIL USE AND IMPACTS --- p.159 / Chapter CHAPTER VIII --- CONCLUSION / SUMMARY OF FINDINGS --- p.162 / LIMITATION OF THE STUDY --- p.164 / SUGGESTIONS FOR FUTURE RESEARCH --- p.164 / BIBLIOGRAPHY --- p.167 / APPENDIX / DESCRIPTIONS OF SELECTED DEGRADED SITES --- p.179

by Choi Chi Hoi. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1991. / Bibliography: leaves 171-178. / ABSTRACT --- p.iii / ACKNOWLEDGMENTS --- p.v / TABLE OF CONTENT --- p.vi / LIST OF FIGURES --- p.x / LIST OF TABLES --- p.xii / LIST OF PHOTOS --- p.xiv / LIST OF APPENDICES --- p.xvi / Chapter I --- INTRODUCTION / Chapter 1.1 --- Background --- p.1 / Chapter 1.2 --- Objectives --- p.6 / Chapter 1.3 --- Uniqueness and Significance of the Study --- p.7 / Chapter 1.4 --- Some Key Concepts --- p.9 / Chapter 1.5 --- Organization of the Thesis --- p.11 / Chapter II --- THE STUDY AREA / Chapter 2.1 --- Selection of the Study Area --- p.12 / Chapter 2.2 --- The Physical and Socio-Economic Environment of the Deqing County --- p.17 / Chapter 2.2.1 --- Location --- p.17 / Chapter 2.2.2 --- Climate --- p.17 / Chapter 2.2.3 --- Geology and Landform --- p.18 / Chapter 2.2.4 --- Vegetation --- p.18 / Chapter 2.2.5 --- Population and Economic Activities --- p.19 / Chapter 2.2.6 --- History of Soil Erosion and Conservation --- p.21 / Chapter 2.3 --- The Shenchong Basin --- p.26 / Chapter 2.4 --- The Lichong Basin --- p.28 / Chapter 2.5 --- The Resource Base of Deqing --- p.30 / Chapter III --- METHODOLOGY --- p.34 / Chapter 3.1 --- Conceptual Considerations --- p.34 / Chapter 3.2 --- Land Degradation Processes --- p.35 / Chapter 3.2.1 --- Nutrient Loss from Hillslopes --- p.38 / Chapter 3.2.2 --- Iron Toxicity --- p.43 / Chapter 3.2.3 --- Properties and Nutrient Status of Rehabilitated Soils --- p.44 / Chapter 3.2.4 --- Methods of Chemical Analysis of Water and Soil Samples --- p.49 / Chapter 3.3 --- Cost-Benefit Analysis of Rehabilitation Measures --- p.50 / Chapter 3.4 --- Problems and Limitations --- p.54 / Chapter IV --- LAND DEGRADATION： PROCESSES AND PROBLEMS --- p.56 / Chapter 4.1 --- Landscape Changes in a Severely Eroded Granitic Area --- p.56 / Chapter 4.2 --- Land Degradation Processes 一 On-site Effects --- p.60 / Chapter 4.2.1 --- Soil Loss on the Hillsides --- p.60 / Chapter 4.2.2 --- Loss of productivity on the Hillsides --- p.64 / Chapter 4.3 --- Land Degradation Process - Off-Site Effects --- p.70 / Chapter 4.3.1 --- Burial of Agricultural Land Beneath Alluvial Fans --- p.70 / Chapter 4.3.2 --- Concentration of Dissolved Iron in Sub-surface Water --- p.74 / Chapter 4.4 --- Concluding Remarks --- p.78 / Chapter V --- COST-EFFECTIVENESS OF EROSION CONTROL MEASURES THEORETICAL CONSIDERATIONS --- p.80 / Chapter 5.1 --- Introduction --- p.80 / Chapter 5.2 --- Economic-Biophysical Management Linkages in the Shenchong Basin --- p.80 / Chapter 5.3 --- Range of Erosion Control/Land Use Options --- p.83 / Chapter 5.4 --- Methodology --- p.83 / Chapter 5.4.1 --- Data Sources --- p.85 / Chapter 5.4.2 --- Economic Valuation Techniques --- p.85 / Chapter 5.5 --- Cost-Effectiveness Evaluation of Erosion- Control Measures --- p.87 / Chapter 5.5.1 --- Option 1 - Hillsides are Maintained Under Dense Fern and Tree Cover and No Use is Permitted --- p.88 / Chapter 5.5.2 --- Option 2 : Slope - Maintaining Dense Vegetation Cover but Permitting Sustained Yield Harvesting of Fern for Fuel and Resin and Timber Production --- p.90 / Chapter 5.5.3 --- Option 3 : Slope - Building Terraces on Hillslopes --- p.92 / Chapter 5.5.4 --- Option 4 : Slope - No Erosion Control Measures --- p.94 / Chapter 5.5.5 --- Option 5 : Slope - Conversion from Fern and Woodland to Baji and Yu Gui Crops --- p.94 / Chapter 5.5.6 --- Option 6 - Small Check Dams Constructed to Control Gully Erosion --- p.94 / Chapter 5.5.7 --- Option 7 : Gully - Large Check Dams --- p.97 / Chapter 5.5.8 --- Option 8 : Gully - Biological Dams --- p.98 / Chapter 5.5.9 --- Option 9 : Gully - Infilling of Gullies --- p.99 / Chapter 5.5.10 --- Option 10 : gully - No Erosion Control --- p.100 / Chapter 5.6 --- Policy Implications --- p.100 / Chapter 5.7 --- Policy Optimization With Multiple-Objective Decision Modeling --- p.102 / Chapter VI --- REHABILITATION PROGRAM AT SHENCHONG AND LICHONG RECONSIDERED --- p.107 / Chapter 6.1 --- Introduction --- p.107 / Chapter 6.2 --- Land Rehabilitation at Shenchong --- p.107 / Chapter 6.3 --- Land Rehabilitation at Lichong --- p.111 / Chapter 6.4 --- Ecological Considerations --- p.119 / Chapter 6.5 --- Agricultural Considerations --- p.124 / Chapter 6.5.1 --- Chemical Soil Properties --- p.126 / Chapter 6.5.2 --- Physical Soil Property --- p.135 / Chapter 6.6 --- Economic Considerations --- p.143 / Chapter 6.6.1 --- Costs and Benefits of Rehabilitation Activities --- p.144 / Chapter 6.6.2 --- Sustainability of the Rehabilitation Programs --- p.146 / Chapter 6.6.3 --- Distribution of Costs and Benefits over Time --- p.148 / Chapter 6.7 --- Institutional Considerations --- p.151 / Chapter 6.7.1 --- Rural Economic Reform --- p.152 / Chapter 6.7.2 --- Institution Set-up of the Two Brigades --- p.153 / Chapter 6.7.3 --- Distribution of Cost and Benefits --- p.154 / Chapter 6.7.4 --- Risk Management --- p.155 / Chapter 6.7.5 --- Land Use Planning --- p.156 / Chapter 6.7.6 --- Motivation --- p.157 / Chapter 6.7.7 --- The Search for Solution --- p.159 / Chapter VII --- CONCLUSION --- p.162 / Chapter 7.1 --- Introduction --- p.162 / Chapter 7.2 --- Discussion --- p.166 / BIBLIOGRAPHY --- p.171 / APPENDICES --- p.179