Thesis. 1978. Sc.D.--Massachusetts Institute of Technology. Dept. of Civil Engineering. / Vita. / Bibliography: leaves 342-349. / Sc.D.

No description available.

This purpose of this study was to assess ground disturbance from harvesting hardwood stands with conventional rubber-tired skidders on slopes greater than 30 percent in Virginia. Special emphasis was placed on erosion, compaction and soil movement. Ten randomly selected study areas were clear-cut between September 1988 and August 1989; measurements followed between March 1989 and August 1989. Potential erosion was estimated using the Universal Soil Loss Equation and soil mechanical strength was measured with a cone penetrometer. Volumes of soil movement resulting from skid trails, landings, and waterbars were measured. Circular plots were used to estimate the percentage of each tract in seven disturbance classes. Descriptive data documented during the study includes land ownership, precipitation records, soil survey information, equipment (make, model, tire size), and volume of the products removed during harvesting. Results show a relatively small amount of soil disturbance associated with harvesting these tracts. Erosion estimates for seven of the ten tracts were below 1.08 tons/acre/year and only one was greater than 3.0 tons/acre/year. The erosion potential for these areas will decrease with time as vegetation increases. The primary source of ground disturbance within the harvested areas was due to skid trails, which occupied 3 to 10 percent of the ground surface. Tracts using overland skid trails experienced far less disturbance than those with bladed skid trails. Following harvest, the undisturbed area ranged from 73 to 81 percent on the ten study tracts. Scheduling practices, tract layout, and tract closure techniques concentrated in high risk spots, can greatly reduce the impact of harvesting steep slopes. / Master of Science

While the applications of Geographic Information Systems (GIS) have progressed from a descriptive tool to a decision making and modeling tool, the understanding of errors and variability of the components of a GIS has lagged behind. Slope is one of these components. This dissertation evaluates different methods for determining and characterizing slope values in polygons and how these methods affect natural resource models. Eight different previously used methods for determining cell slope values were compared using elevation data from the USGS Big Stone Gap, Virginia, Digital Elevation Model. The 28 pairwise comparisons were statistically different, but for practical applications six of the comparisons were similar with an average slope difference of less than one percent. In a decision model the effect of changing just the slope method used to determine cell slope values can influence the results of a model enough to cause almost a 10 fold difference. Since usually the smallest administered unit in natural resource management is the stand (polygon), nine ways of describing the slope of a polygon for 240 polygons using an aggregation of cell slope values were investigated. These polygon descriptors were mean, trim mean, median, mode, first quartile, third quartile, standard deviation, minimum and maximum cell slope value. Also, a new method of determining polygon slope was examined using trend surface techniques, which is not based on aggregation of single cell slope values. The distributions of cell slope values in a polygon cannot be assumed normal since few polygons had a normal distribution. The sensitivity of these polygon slope descriptors to polygon area and surface complexity, based on fractal dimension, was examined and found not to affect these polygon characteristics. The application and logical decisions required to choose an appropriate slope method and polygon slope descriptor(s) based on model objectives are shown in two examples, a harvesting and USLE model. Automating the process of choosing the appropriate polygon slope descriptor(s) and how to integrate these methods in an operational GIS using an Expert System is discussed. / Ph. D.

Lam, Shu Kee. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (leaves 206-219). / Abstracts in English and Chinese. / Abstract --- p.i / Abstract (in Chinese) --- p.iv / Acknowledgements --- p.vi / Table of contents --- p.vii / List of tables --- p.xii / List of figures --- p.xvi / List of plates --- p.xvii / Chapter CHAPTER 1 --- INTRODUCTION / Chapter 1.1 --- Research background --- p.1 / Chapter 1.2 --- Conceptual framework --- p.4 / Chapter 1.3 --- Objectives of the study --- p.8 / Chapter 1.4 --- Significance of the study --- p.9 / Chapter 1.5 --- Organization of the thesis --- p.10 / Chapter CHAPTER 2 --- LITERATURE REVIEW / Chapter 2.1 --- Introduction --- p.12 / Chapter 2.2 --- Use of hydroseeding in slope bioengineering works --- p.12 / Chapter 2.3 --- Problems associated with hydroseeded slopes --- p.12 / Chapter 2.4 --- Common Bermudagrass used in hydroseeding --- p.13 / Chapter 2.5 --- "Sludge disposal, potentials and problems" --- p.14 / Chapter 2.5.1 --- Properties and disposal of sludge --- p.14 / Chapter 2.5.2 --- Use of sludge and potential problems --- p.16 / Chapter 2.5.3 --- Heavy metals in sludge --- p.19 / Chapter 2.5.3.1 --- Cadmium --- p.22 / Chapter 2.5.3.2 --- Chromium --- p.22 / Chapter 2.5.3.3 --- Copper --- p.23 / Chapter 2.5.3.4 --- Nickel --- p.24 / Chapter 2.5.3.5 --- Lead --- p.24 / Chapter 2.5.3.6 --- Zinc --- p.25 / Chapter 2.5.4 --- Speciation of heavy metals --- p.25 / Chapter 2.5.5 --- Factors affecting the bioavailability of heavy metals --- p.26 / Chapter 2.5.5.1 --- Reaction pH --- p.26 / Chapter 2.5.5.2 --- Organic matter --- p.28 / Chapter 2.5.5.3 --- Fertilizers --- p.29 / Chapter 2.5.6 --- Effect of heavy metals on plant growth --- p.29 / Chapter 2.5.7 --- Effect of heavy metals on animals and water bodies --- p.31 / Chapter 2.6 --- "Lime, heavy metals and plant growth" --- p.32 / Chapter 2.6.1 --- Effect of lime on heavy metal dynamics --- p.32 / Chapter 2.6.1.1 --- Competition with heavy metals for adsorption sites --- p.32 / Chapter 2.6.1.2 --- Immobilization of heavy metals --- p.32 / Chapter 2.6.2 --- Effect of lime on plant growth --- p.34 / Chapter 2.7 --- Effect of precipitation on slopes --- p.35 / Chapter 2.7.1 --- Infiltration --- p.35 / Chapter 2.7.2 --- Surface runoff --- p.38 / Chapter 2.7.3 --- Soil erosion --- p.39 / Chapter 2.8 --- Summary --- p.42 / Chapter CHAPTER 3 --- EFFECT OF SLUDGE AND LIME ON ABOVEGROUND BIOMASS OF COMMON BERMUDAGRASS / Chapter 3.1 --- Introduction --- p.43 / Chapter 3.2 --- Materials and methods --- p.44 / Chapter 3.2.1 --- Materials --- p.45 / Chapter 3.2.2 --- Experimental design --- p.46 / Chapter 3.2.3 --- Grass clipping and pre-treatment --- p.49 / Chapter 3.3 --- Chemical analysis --- p.50 / Chapter 3.3.1 --- Properties of decomposed granite --- p.50 / Chapter 3.3.2 --- "Properties of sludge," --- p.52 / Chapter 3.3.3 --- Nitrogen of grass clippings --- p.52 / Chapter 3.4 --- Statistical analysis --- p.53 / Chapter 3.5 --- Results and discussion --- p.54 / Chapter 3.5.1 --- Properties of DG and sludge --- p.54 / Chapter 3.5.2 --- Aboveground biomass of grass --- p.56 / Chapter 3.5.3 --- Effect of sludge on aboveground biomass --- p.63 / Chapter 3.5.4 --- Effect of lime on aboveground biomass --- p.66 / Chapter 3.5.5 --- Synergic effect of sludge and lime on aboveground biomass --- p.68 / Chapter 3.5.6 --- "Effect of sludge on nitrogen uptake by grass shoots," --- p.69 / Chapter 3.6 --- Summary --- p.72 / Chapter CHAPTER 4 --- EFFECT OF SLUDGE AND LIME ON HEAVY METAL UPTAKE BY COMMON BERMUDAGRASS / Chapter 4.1 --- Introduction --- p.74 / Chapter 4.2 --- Materials and methods --- p.77 / Chapter 4.2.1 --- Materials and experimental design --- p.77 / Chapter 4.2.2 --- Analysis of heavy metals in grass shoots --- p.77 / Chapter 4.2.3 --- Reaction pH at the end of Part 1 --- p.77 / Chapter 4.2.4 --- Statistical analysis --- p.78 / Chapter 4.3 --- Results and discussion --- p.78 / Chapter 4.3.1 --- Cumulative uptake of heavy metals by common Bermudagrass --- p.79 / Chapter 4.3.2 --- Effect of sludge on heavy metal uptake --- p.84 / Chapter 4.3.3 --- Effect of lime on heavy metal uptake --- p.86 / Chapter 4.3.4 --- Synergic effect of sludge and lime on cumulative heavy metal uptake --- p.88 / Chapter 4.3.5 --- Effect of fertilizer addition --- p.91 / Chapter 4.3.6 --- Concentration of heavy metals in grass --- p.93 / Chapter 4.3.7 --- Effect of pH on heavy metal uptake --- p.98 / Chapter 4.3.8 --- Effect of heavy metal uptake on aboveground biomass --- p.100 / Chapter 4.4 --- Summary --- p.103 / Chapter CHAPTER 5 --- EFFECT OF SLUDGE AND LIME ON HEAVY METALS IN LEACHATE / Chapter 5.1 --- Introduction --- p.106 / Chapter 5.2 --- Materials and methods --- p.107 / Chapter 5.2.1 --- Leachate collection --- p.108 / Chapter 5.2.2 --- Analysis of leachate --- p.109 / Chapter 5.2.3 --- Statistical analysis --- p.109 / Chapter 5.3 --- Results and discussion --- p.110 / Chapter 5.3.1 --- Effect of sludge and lime on leachate volume --- p.110 / Chapter 5.3.2 --- Leachate pH and the effect of sludge and lime --- p.115 / Chapter 5.3.3 --- Heavy metal contents in leachate --- p.119 / Chapter 5.3.4 --- Effect of sludge and lime on the leaching of heavy metals --- p.121 / Chapter 5.3.5 --- Effect of pH on the leaching of heavy metals --- p.125 / Chapter 5.4 --- Summary --- p.126 / Chapter CHAPTER 6 --- "LEACHATE, SURFACE RUNOFF, SEDIMENT YIELD AND THEIR HEAVY METALS" / Chapter 6.1 --- Introduction --- p.128 / Chapter 6.2 --- Materials and methods --- p.130 / Chapter 6.2.1 --- Materials --- p.130 / Chapter 6.2.2 --- Experimental design --- p.132 / Chapter 6.2.3 --- Rainfall intensities in simulation experiment --- p.134 / Chapter 6.2.4 --- Selection of slope gradient --- p.136 / Chapter 6.2.5 --- Rainfall simulation --- p.136 / Chapter 6.2.6 --- "Leachate, surface runoff and runoff sediment" --- p.137 / Chapter 6.2.7 --- Properties of decomposed granite and sludge --- p.138 / Chapter 6.2.8 --- "Heavy metals in leachate, surface runoff and runoff sediment" --- p.139 / Chapter 6.2.9 --- Statistical analysis --- p.140 / Chapter 6.3 --- Results and discussion --- p.140 / Chapter 6.3.1 --- Properties of DG and sludge --- p.140 / Chapter 6.3.2 --- "Leachate, surface runoff and runoff sediment production" --- p.142 / Chapter 6.3.3 --- "Heavy metal concentrations in leachate, surface runoff and runoff sediment" --- p.153 / Chapter 6.3.3.1 --- Heavy metal concentrations in leachate --- p.153 / Chapter 6.3.3.2 --- Heavy metal concentrations in runoff --- p.163 / Chapter 6.3.4 --- Cumulative loss of heavy metals --- p.170 / Chapter 6.3.4.1 --- Cumulative loss of heavy metals from leachate --- p.170 / Chapter 6.3.4.2 --- Cumulative loss of heavy metals from runoff --- p.178 / Chapter 6.3.4.3 --- "Heavy metal loss from leachate, surface runoff and runoff sediment" --- p.185 / Chapter 6.4 --- Summary --- p.189 / Chapter CHAPTER 7 --- CONCLUSIONS / Chapter 7.1 --- Summary of major findings --- p.192 / Chapter 7.2 --- Implications of the study --- p.196 / Chapter 7.2.1 --- Potential use of sludge in slope bioengineering works --- p.196 / Chapter 7.2.2 --- Measures to optimize the benefits of sludge in land application --- p.198 / Chapter 7.3 --- Limitations of the study --- p.200 / Chapter 7.4 --- Suggestions for further study --- p.202 / REFERENCES --- p.206 / APPENDICES --- p.220

Deep foundations, including driven piles, are used to support vertical loads of structures and applied lateral forces. Many pile supported structures, including bridges, are subjected to large lateral loads in the form of wind, wave, seismic, and traffic impact loads. In many practical situations, structures subjected to lateral loading are located near or in excavated and fill slopes or embankments. Full-scale research to examine the effects of soil slope on lateral pile capacity is limited. The purpose of this study is to examine the effects on lateral capacity of piles located in or near cohesionless soil slopes. A full-scale lateral load testing program was undertaken on pipe piles in a cohesionless soil at Oregon State University. Five piles were tested near a 2H:1V test slope and located between 0D to 8D behind the slope crest, where D is the pile diameter. Two vertical baseline piles and three battered piles were also tested in level ground conditions. The cohesionless backfill soil was a well-graded material with a fines content of less than 10% and a relative compaction of 95%, meeting the Caltrans specification for structural backfill. Data collected from the instrumented piles was used to back calculate p-y curves, load-displacement curves, reduction factors, and load resistance ratios for each pile. The effects of slope on lateral pile capacity are insignificant at displacements of less than 2.0 inches for piles located 2D and further from the crest. For pile located at 4D or greater from the slope crest, the effect of slope is insignificant on p-y curves. A simplified p-multiplier design procedure derived from back-calculated p-y curves is proposed to account for the effects of soil slope. Comparisons of the full-scale results were made using proposed recommendations from the available literature. Lateral resistance ratios obtained by computer, centrifuge, and small scale-models tend to be conservative and overestimate the effects of slope on lateral capacities. Standard cohesionless p-y curve methods slightly over predict the soil resistance at very low displacements but significantly under predict the ultimate soil resistance. Available reduction factors from the literature, or p-multipliers, are slightly conservative and compare well with the back-calculated p-y curves from this study. / Graduation date: 2012

In unstable landscapes, modern pedological research explores the role of soils as products and indicators of geomorphologic change. Understanding the dynamics of hill slope pedogenesis is especially important in regions with limited, poor, or threatened soil resources. The island of Cyprus, situated in the eastern Mediterranean, is claimed by many authors to exhibit signs of severe soil degradation and is a prime site for comparative soil geomorphologic research. This study strove to 1) identify the controls of soil genesis and landscape stability within the Troodos Mountains of Cyprus using image and GIS analysis; 2) compare toposequence data to expected soil thickness trends from traditional models of xeric soil toposequences prevalent in current scientific literature; and 3) develop a predictive model for hillslope pedogenesis based on measured soil properties within the field area. Study soils within the Troodos are thin, weakly developed Lithic and Typic Xerorthents formed in colluvium derived from fractured, igneous bedrock. Soil thickness was measured at 368 sites in seven transects across three watersheds in the Troodos, using interpretations of field profiles and image analysis of digital soil-bedrock profiles in photographed road-cuts along forestry paths. Soil thickness was compared through GIS and statistical analysis to landscape attributes derived from a 25-m DEM and other map data. Results indicate that lithology is the only factor of several studied to have a significant relationship with the variability of soil-profile thickness in the Troodos, and that soil thickness does not vary in a predictable manner across toposequences. These results, combined with differences between measured soil data and values predicted by the landscape stability model SHALSTAB, suggest that soil genesis in the Troodos is best described only within the context of a weathering-limited geomorphological system. Short-term disruptive processes such as forest fires, land sliding, tree throw, and raindrop impact, combined with long-term processes such as tectonic uplift and stream incision, are the most likely driving forces behind the rapid erosion of hill slope sediments and the weak development of Troodos hill slope soils. These findings have important implications for DEM-based, predictive soil mapping in weathering-limited geomorphologic systems. / Graduation date: 2005

abstract / Civil Engineering / Doctoral / Doctor of Philosophy

published_or_final_version / Geography and Geology / Master / Master of Philosophy

published_or_final_version / Civil Engineering / Master / Master of Philosophy