Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 75 for “"Overland Flow"”.
-
Overland flow on disturbed soil
… roughness storage and hydraulic resistance of overland flow. Experimental plots, with four types of tillage implemented roughness, were equipped with piezometer sets buried under the surface to measure hydrostatic pressure and a system of flow tracers composed of floating objects, border …
-
Characterization of pathogen transport in overland flow
Overland transport kinetics of pathogens are controlled, in large part, by soil and vegetation. With an increasing number of concentrated animal operations, there is becoming a greater need to dispose of a vast amount of manure in a single, localized area. Animal manure contains a substantial …
-
Simulation of pesticide availability and transfer into overland flow
Factors which affect the availability and transfer of soil applied pesticides to runoff water on the soil surface were investigated. This research was composed of three major components: field investigation of pesticide transport as a function of pesticide formulation and application technique, …
-
Determining overland flow hydrographs from sections of nonuniform width
Dimensionless hydrographs and equations for the time of equilibrium were developed for sections of nonuniform width. In order to determine the dimensionless hydrographs the equations of momentum and continuity were solved implicitly. This method was chosen because it is unconditionally stable …
-
Modeling fate and transport of Cryptosporidium parvum and rotavirus in overland flow
… of C. parvum oocyst and rotavirus in surface flow. Laboratory experiments conducted at the University of Illinois have demonstrated C. parvum oocysts and rotavirus transport is greatly influenced by climatic and soil-surface conditions like slope, soil types, soil texture, and ground cover. …
-
Concentration of Suspended Solids and Nutrients in Overland Flow in Suburban Philadelphia Watersheds
… consisted of upstream headwaters to four streams flowing into the Delaware River. The objective of this study was to determine sediment and nutrient concentrations in first flush overland flow (OLF) in three of the DRWI focus areas. Seven sites were selected for collection of OLF, stream, and rain …
-
Effect of tillage on rainfall infiltration and surface depressional storage
… Values of Manning's resistance coefficient and overland flow velocity were calculated using the detention storage depth. Comparisons between observed and calculated overland flow velocities were made.
-
Using Accumulation Based Network Identification Methods to Identify Hill Slope Scale Drainage Networks in a Raster GIS
… the use of ANIMs for deriving properties such as overland flow length for nonpoint source pollution models, without calibrating the accumulation threshold value. However, the basic assumption that underlies ANIMs is that convergent topography will yield a more rapid accumulation of cells, and …
-
Identification of catchment runoff processes as a basis for defining water quality protection zones
… of generation of different hydrological flow pathways and to recommend hydrology-based protection zones for overland flow within an agricultural catchment. The study is based in the 616 km2 Upper Eden catchment in Cumbria, and one of its subcatchments, Blind Beck (8.8 km2). Transfer …
-
Investigation of Partial Contributing Areas in Watersheds With a Conjunctive Surface Subsurface Flow Model
… developed a physically based conjunctive flow model (CFM) coupling two-dimensional surface three-dimensional subsurface transport to simulate the total runoff in watersheds. In conjunction with the CFM, an overland flow-tracking program (OFTP) was developed to compute the PCA under the …
-
Near-surface hydrology and hydrochemistry under contrasting land-cover
… to differences of the relative importance of flowpaths. This study was conducted in the southwestern part of the Brazilian Amazon basin. An intensive hydrological and hydrochemical sampling and monitoring network was set up. The results indicate that the hydrology was modified in many ways due …
-
Farm-scale Water Management in Adaptation to Climate Change in Morocco
… adapt to these dryer conditions and to collect overland flow for irrigation purposes before its evaporation or infiltration into the ground. We investigate a potential shift from basin-scale to farm-scale water resource management. A prototype of such small reservoirs has been built in the …
-
Saturated hydraulic conductivity in the humid tropics : sources of variability, implications for monitoring and effects on near-surface hydrological flow paths
… key soil properties which determine hydrological flow paths. One of these key properties sensitive to land-use change is the saturated hydraulic conductivity (Ks) as it governs vertical percolation of water within the soil profile. Low values of Ks in a certain soil depth can form an impeding …
-
Time characteristics of small watersheds in response to the probable maximum precipitation
… Loss Lake watershed in southcentral Missouri. Overland flow was simulated using kinematic wave routing and channel flow was simulated using dynamic wave routing.</p> <p>Lag time was defined as the time between the centroid of the excess rainfall hyetograph and the centroid of the direct runoff …
-
Hydrological and erosion responses to man-made and natural disturbances : insights from forested catchments in South-central Chile
… behavior of timber harvest areas in terms of overland flow generation and sediment fluxes, 3) geomorphic work and its efficiency as a function of seasonal logging, 4) possible hydrologic responses of the saturated zone to the 2010 Maule earthquake and 5) responses of the vadose zone to this …
-
Numerically Simulated Soil Surface Degradation (Erosion, Hydraulics)
… soil erosion require consideration of rainfall, overland flow, erosion, sediment transport and soil surface changes due to erosion.
-
Turbidity and Nutrient Response to Storm Events in the Wissahickon Creek, Suburban Philadelphia, PA
… to determine the relative roles of WWTPs and overland flow as sources of turbidity and nutrients during storm events. The upstream site and first downstream site at each WWTP were monitored for nutrients during storms using high frequency loggers and ISCO automatic samplers. Stream assessments …
-
Streamside Management Zone effectiveness for protecting water quality following forestland application of biosolids
… to the treated streams, we collected overland flow samples, soil solution samples at 60 cm and extracts from ion exchange membranes (IEMs) placed in the surface soil. We found elevated nitrate concentrations outside the SMZ in the treated side soil solution samples, in which …
-
Statistical-Based Hydrological Simulation and Inference
… the spatial autocorrelation of daily streamflow; (2) a Wilks feature importance (WFI) method that provides reliable variable rankings for supporting hydrological inference and simulation (through a stepwise clustered ensemble (SCE) model); (3) a baseflow-filtered stepwise clustered ensemble …
Page 1 of 4