The Experts below are selected from a list of 11310 Experts worldwide ranked by ideXlab platform
Dennis C. Flanagan - One of the best experts on this subject based on the ideXlab platform.
-
geospatial application of the water Erosion Prediction project wepp model
Transactions of the ASABE, 2013Co-Authors: Dennis C. Flanagan, James R Frankenberger, Chris S. Renschler, T A Cochrane, William J. ElliotAbstract:Abstract. At the hillslope profile and/or field scale, a simple Windows graphical user interface (GUI) is available to easily specify the slope, soil, and management inputs for application of the USDA Water Erosion Prediction Project (WEPP) model. Likewise, basic small watershed configurations of a few hillslopes and channels can be created and simulated with this GUI. However, as the catchment size increases, the complexity of developing and organizing all WEPP model inputs greatly increases due to the multitude of potential variations in topography, soils, and land management practices. For these types of situations, numerical approaches and special user interfaces have been developed to allow for easier WEPP model setup, utilizing either publicly available or user-specific geospatial information, e.g., digital elevation models (DEMs), geographic information system (GIS) soil data layers, and GIS land use/land cover data layers. We utilize the Topographic Parameterization (TOPAZ) digital landscape analysis tool for channel, watershed, and subcatchment delineation and to derive slope inputs for each of the subcatchment hillslope profiles and channels. A user has the option of specifying a single soil and land management for each subcatchment or utilizing the information in soils and land use/land cover GIS data layers to automatically assign those values for each grid cell. Once WEPP model runs are completed, the output data are analyzed, results interpreted, and maps of spatial soil loss and sediment yields are generated and visualized in a GIS. These procedures have been used within a number of GIS platforms including GeoWEPP, an ArcView/ArcGIS extension that was the first geospatial interface to be developed in 2001. GeoWEPP allows experienced GIS users the ability to import and utilize their own detailed DEM, soil, and/or land use/land cover information or to access publicly available spatial datasets. A web-based GIS system that used MapServer web GIS software for handling and displaying the spatial data and model results was initially released in 2004. Most recently, Google Maps and OpenLayers technologies have been integrated into the web WEPP GIS software to provide significant enhancements. This article discusses in detail the logic and procedures for developing the WEPP model inputs, the various WEPP GIS interfaces, and provides example real-world geospatial WEPP applications. Further work is ongoing in order to expand these tools to allow users to customize their own inputs via the internet and to link the desktop GeoWEPP with the web-based GIS system.
-
The development of U. S. soil Erosion Prediction and modeling
International Soil and Water Conservation Research, 2013Co-Authors: John Matthew Laflen, Dennis C. FlanaganAbstract:Soil Erosion Prediction technology began over 70 years ago when Austin Zingg published a relationship between soil Erosion (by water) and land slope and length, followed shortly by a relationship by Dwight Smith that expanded this equation to include conservation practices. But, it was nearly 20 years before this work's expansion resulted in the Universal Soil Loss Equation (USLE), perhaps the foremost achievement in soil Erosion Prediction in the last century. The USLE has increased in application and complexity, and its usefulness and limitations have led to the development of additional technologies and new science in soil Erosion research and Prediction. Main among these new technologies is the Water Erosion Prediction Project (WEPP) model, which has helped to overcome many of the shortcomings of the USLE, and increased the scale over which Erosion by water can be predicted. Areas of application of Erosion Prediction include almost all land types: urban, rural, cropland, forests, rangeland, and construction sites. Specialty applications of WEPP include Prediction of radioactive material movement with soils at a superfund cleanup site, and near real-time daily estimation of soil Erosion for the entire state of Iowa.
-
improving frost simulation subroutines of the water Erosion Prediction project wepp model
Transactions of the ASABE, 2010Co-Authors: Joan Q Wu, Donald K Mccool, James R Frankenberger, Dennis C. FlanaganAbstract:Erosion models play an important role in assessing the influence of human activities on the environment. For cold areas, adequate frost simulation is crucial for predicting surface runoff and water Erosion. The Water Erosion Prediction Project (WEPP) model is a physically based Erosion Prediction software program developed by the USDA. One of the major components of WEPP is the simulation of winter processes, which include snow accumulation and melt as well as soil freeze and thaw. WEPP is successfully used in the evaluation of important natural resource issues throughout the U.S. and in a number of other countries. However, previous studies revealed problems in the winter component of the WEPP model, especially the routine for frost simulation. The main purpose of this study was to improve the WEPP model (v2006.5) by changing the soil profile discretization and computation of key thermal and hydraulic parameters in the frost simulation routines so that the model can adequately simulate soil freeze-thaw and winter runoff and Erosion. WEPP v2006.5 and the modified version (v2010.1) were applied to experimental plots in Pullman, Washington, and Morris, Minnesota. The simulated snow and frost depths as well as runoff and sediment yield were contrasted and compared with field observations; the results from v2010.1 showed substantial improvement compared to those from v2006.5.
-
Implementation of channel-routing routines in the Water Erosion Prediction Project (WEPP) model
2010Co-Authors: Li Wang, Shuhui Dun, William J. Elliott, Sergey Lapin, Fritz R. Fiedler, Dennis C. FlanaganAbstract:The Water Erosion Prediction Project (WEPP) model is a process-based, continuous-simulation, watershed hydrology and Erosion model. It is an important tool for water Erosion simulation owing to its unique functionality in representing diverse landuse and management conditions. Its applicability is limited to relatively small watersheds since its current version does not simulate flow in permanent channels. In this study we developed a channel-routing module to simulate water flow in a permanent channel network. The module can utilize two methods: numerical kinematic-wave method and Muskingum-Cunge method. Results showed that, for appropriate temporal and spatial discretizations, both numerical solutions compared well with analytical solution of kinematic wave equations for simplified cases; otherwise, numerical dissipation from the kinematic wave solution, and numerical dispersion from the Muskingum-Cunge solution would occur.
-
Adapting the Water Erosion Prediction Project (WEPP) model for forest applications
Journal of Hydrology, 2009Co-Authors: Shuhui Dun, Dennis C. Flanagan, William J. Elliot, James R Frankenberger, Peter R. Robichaud, Robert E. BrownAbstract:summary There has been an increasing public concern over forest stream pollution by excessive sedimentation due to natural or human disturbances. Adequate Erosion simulation tools are needed for sound management of forest resources. The Water Erosion Prediction Project (WEPP) watershed model has proved useful in forest applications where Hortonian flow is the major form of runoff, such as modeling Erosion from roads, harvested units, and burned areas by wildfire or prescribed fire. Nevertheless, when used for modeling water flow and sediment discharge from natural forest watersheds where subsurface flow is dominant, WEPP (v2004.7) underestimates these quantities, in particular, the water flow at the watershed outlet.
J. M. Laflen - One of the best experts on this subject based on the ideXlab platform.
-
Simulating small watersheds with water Erosion Prediction project technology.
2001Co-Authors: Dennis C. Flanagan, J. M. Laflen, J. R. Frankenberger, Chris S. Renschler, Bernard A. Engel, James C. AscoughAbstract:The USDA Water Erosion Prediction Project (WEPP) model is a continuous simulation, process-based soil Erosion model that allows simulation of small watersheds and hillslope profiles within those watersheds. A major problem that has impeded full implementation and use of WEPP since its public release in 1995 has been the lack of a modern, easy-to-use, Windows interface, particularly for watershed applications. Concentrated effort on watershed interfaces for WEPP has been underway at the National Soil Erosion Research Laboratory (NSERL) since 1997. The most basic watershed interface requires that the user enter information on the screen to delineate the channels, hillslope profiles, and impoundments that comprise the watershed. Background photographs (for example scanned from soil surveys), can be imported and used to assist in defining the watershed. Drawing tools allow orientation, scaling, and placement of polygons to match field areas. The visual representation is then converted to a group of hillslope, channel, impoundment and watershed structure files by the interface. After creating the appropriate input files, the interface executes the WEPP model and provides model simulation results in text format and graphically displays outputs on the user-delineated screen image. Additional work is also in progress to allow WEPP watershed model simulations through linkage with Geographic Information Systems (GIS) utilizing digital elevation data.
-
The Water Erosion Prediction Project ( WEPP ) Model
Landscape Erosion and Evolution Modeling, 2001Co-Authors: Dennis C. Flanagan, M. Nearing, James C. Ascough, J. M. LaflenAbstract:Soil Erosion by water continues to be a serious problem throughout the world, and models play an increasingly critical role in conservation and assessment efforts. Improved soil Erosion Prediction technology is needed to provide land managers, conservationists and others with tools to examine the impact of different land management decisions on on-site soil loss and off-site sediment yield and determining optimal land use. Additionally, soil Erosion Prediction technology allows policymakers to assess the current status of land resources and the potential need for enhanced or new policies to protect soil and water resources.
-
Development and application of modern soil Erosion Prediction technology : The USDA experience
Eurasian Soil Science, 1997Co-Authors: L. J. Lane, G. R. Foster, K. G. Renard, J. M. LaflenAbstract:Erosion Prediction efforts are described to provide a synopsis of the USDA's experience in developing and applying soil Erosion Prediction technology in its research and development activities and its soil conservation programs. The Universal Soil Loss Equation (USLE) is the most widely known and used of the Erosion Prediction equations. The Chemicals, Runoff, and Erosion from Agricultural Management Systems model (CREAMS) contains a sophisticated Erosion component based, in part, on the USLE and on flow hydraulics and the processes of sediment detachment, transport, and deposition. The Revised Universal Soil Loss Equation (RUSLE) is an update of the USLE to improve Erosion Prediction.
-
The USDA Water Erosion Prediction Project (WEPP)
Eurasian Soil Science, 1997Co-Authors: Dennis C. Flanagan, J. M. LaflenAbstract:The Water Erosion Prediction Project (WEPP) models are intended to replace the Universal Soil Loss Equation for predicting soil Erosion in the United States. The WEPP programs are process-based models that operate on a daily time step to estimate soil, vegetation, and surface residue conditions when a rainfall event occurs. This information is then used to predict the infiltration, runoff, Erosion, and sediment loss for each individual event, and then long-term estimates are made using summations of the single event Predictions. This paper describes the history of the model development and the major components of the WEPP models and provides brief examples of how they may be applied by action agencies.
-
Plant Parameter Database for Erosion Prediction Models
Applied Engineering in Agriculture, 1995Co-Authors: L. A. Deer-ascough, G. A. Weesies, James C. Ascough, J. M. LaflenAbstract:Recently developed Erosion Prediction models require detailed input parameters including those describing cropping systems. Each model requires a different level of detail for crop growth modeling, and most plant parameters for these models are not readily found. Many parameters require interpretation from other measurable plant characteristics. In order to supply the users of these new Erosion Prediction technologies with required parameters, a database containing measurable plant characteristics was developed. The two Erosion Prediction models that the database currently supports are the USDA Revised Universal Soil Loss Equation (RUSLE) and the USDA Water Erosion Prediction Project (WEPP). A Microsoft® Windows™-based program, the Crop Parameter Intelligent Database System (CPIDS), was developed to assist crop database builders and users of RUSLE and WEPP in interpretation of plant characteristics and selection of plant parameters.
Yang Qin-ke - One of the best experts on this subject based on the ideXlab platform.
-
Current progress in water Erosion Prediction project
Agricultural Research in the Arid Areas, 2006Co-Authors: Shi Wan-li, Yang Qin-keAbstract:As a new generation Prediction technology,Water Erosion Prediction Project(WEPP) is a guide to conservation planning and a tool for quantitative researches of soil Erosion.In recent years,Geographic Information Systems(GIS) and Remote Sensing technologies have been introduced for generating,preprocessing and visual display of parameters in WEPP model.Meanwhile,the introduction of regionalization concept makes WEPP application in lager areas.This paper concentrated on the latest development of WEPP and briefly analyzed some potential problems of WEPP applied in China.The object of this paper was to promote the development of soil Erosion predicting model in China through calculating all the advantages and disadvantages of WEPP.
-
Distributed water Erosion Prediction model for small watershed in loess plateau
Journal of Hydraulic Engineering, 2005Co-Authors: Jia Yuan-yuan, Zheng Fen-li, Yang Qin-keAbstract:Based on the grid digital elevation model (DEM), a distributed water Erosion Prediction model for small watershed in loess plateau is established. The model is composed of hydrological component and Erosion component. In the hydrological component, the processes of rainfall, interception, surface storage formed by micro-depression, infiltration, overland flow and channel flow are taken into account, and the implementation of runoff confluence calculation is carried out on the basis of kinetic wave theory. The Erosion component includes the splash detachment, detachment rate formed by interrill flow, rill flow, ephemeral gully flow and channel flow, and the calculation of sediment yield is realized according to the principle of dynamic balance of mass. The simulation result of single rainfall event with rainfall intensity higher than medium grade shows that the accuracy of the Prediction is acceptable.
-
Review on Hillslope Erosion Prediction Models in China
Research of Soil and Water Conservation, 2004Co-Authors: Jia Yuan-yuan, Zheng Fen-li, Yang Qin-keAbstract:By the research of hillslope Erosion Prediction model,the knowledge about the process and the mechanism of soil Erosion were strengthened,and the arrangement of soil and water conservation practice on hillslope were supported.The quantificational evaluation and the research of Prediction model about hillslope Erosion were divided into three stages in China:(1) Hillslope Erosion statistical model based on USLE (Universal Soil Loss Equation);(2) Steep hillslope soil Erosion Prediction model;(3) Physically based hillslope Erosion Prediction model.Finally,considering special Erosion sediment and the complex terrain in our country,some intensified aspects on the establishment of hillslope Erosion Prediction model were advanced,which were the research on the process and the mechanism of ephemeral gully Erosion,the equation of interrill flow,rill flow,ephemeral gully flow,modeling of steep hillslope.
-
Construction of Water Erosion Prediction Model at Small Watershed in the Loess Hilly and Gully Region
Bulletin of Soil and Water Conservation, 2004Co-Authors: Jia Yuan-yuan, Zheng Fen-li, Yang Qin-keAbstract:According to Erosion vertical zone distribution in the loess hilly and gully region, the methods for demarcating distribution slope location of soil Erosion patterns at small watershed are put forward. Based on Erosion environmental characters in the loess hilly and gully region, the framework of the distributed water Erosion Prediction model at small watershed supported by GIS is designed. The fundamental Erosion (processes) in this model included splash detachment, sheet flow detachment and deposition, rill flow detachment and deposition, ephemeral gully flow detachment and deposition, gully flow detachment and deposition, and channel flow detachment and deposition. Meanwhile, the calculation processes of this model are discussed in detail. In term of the principle of dynamic balance of mass, the calculation of sediment yield in the whole watershed is accomplished.
-
Review on Abroad Water Erosion Prediction Models
Bulletin of Soil and Water Conservation, 2003Co-Authors: Yang Qin-keAbstract:Well-known water Erosion Prediction models, such as USLE, RUSLE, WEPP, EROSEM, LISEM and GeoWEPP are outlined. The recently developed regional water Erosion model (SEMMED), rill Erosion model (RILLGROW), shallow gully Erosion model (EGEM), and gully Erosion model are introduced in detail. The challenges in employing these Erosion models in China are discussed.
Siamack A. Shirazi - One of the best experts on this subject based on the ideXlab platform.
-
a comprehensive cfd based Erosion Prediction for sharp bend geometry with examination of grid effect
Wear, 2019Co-Authors: Jun Zhang, Farzin Darihaki, Siamack A. ShiraziAbstract:Abstract A comprehensive CFD-based Erosion Prediction procedure developed previously is applied to predict Erosion in a 90° sharp bend. This paper serves as a further validation of the proposed Computational Fluid Dynamics (CFD) based Erosion Prediction procedure for a different geometry, flow and particle conditions to examine the generalization of this comprehensive CFD-based approach to other geometries. Special emphasis is played on the strong effects of the grids on the resulting Erosion profile representation. Detailed meshing information is provided for repeatable and further improved CFD studies in future. In the process, Erosion Predictions for both large (256 μm ) and small particles (25 μm ) in a sharp bend geometry are performed by applying the comprehensive CFD-based Erosion Prediction procedure. Results are compared with data from the literature and are found to be in a good agreement with data which demonstrates the success of the applied CFD-based Erosion Prediction procedure. It is shown that appropriate meshing, selection of turbulence model and near wall modeling approach are crucial for obtaining good Erosion Prediction results utilizing CFD, especially for small particle Erosion Prediction under the present flow and geometry conditions.
-
Application and experimental validation of a CFD based Erosion Prediction procedure for jet impingement geometry
Wear, 2018Co-Authors: Jun Zhang, Brenton S. Mclaury, Siamack A. ShiraziAbstract:Abstract Computational Fluid Dynamics (CFD) based Erosion Prediction procedures are carried out to predict Erosion for a submerged liquid jet impingement geometry. 3-D modeling with different near wall treatments are employed to simulate the wall bounded turbulent jet flow. Discrete Phase Model (DPM) is applied to track particles and obtain particle impact characteristics. Erosion is calculated using typical Erosion ratio equations in the literature (Zhang et al., 2009) [1]. In this paper, two categories of near wall modeling approaches (wall functions and near wall models) are presented and examined. Particle impact parameters are extracted and compared with measured data to determine the most accurate near wall modeling approaches. A procedure for grid refinement particular for Erosion simulations is proposed and followed by uncertainty analysis from the CFD Predictions. Experimental data with uncertainty quantified for 300 μ m large particles and 25 μ m small particles are utilized to validate the proposed procedure. It is shown that following the proposed procedure yields very good Erosion Prediction from CFD regardless of particle size.
-
Effect of Near Wall Modeling Approaches on Solid Particle Erosion Prediction
Volume 1C Symposia: Gas-Liquid Two-Phase Flows; Gas and Liquid-Solid Two-Phase Flows; Numerical Methods for Multiphase Flow; Turbulent Flows: Issues a, 2017Co-Authors: Jun Zhang, Brenton S. Mclaury, Siamack A. ShiraziAbstract:Computational Fluid Dynamics (CFD) based Erosion Prediction procedures are carried out to predict Erosion for a submerged liquid jet impingement geometry. 2-D axisymmetric modeling with different near wall treatments are employed to model the wall bounded turbulent jet flow. Discrete Phase Model (DPM) is applied to track particles and obtain particle impact characteristics. Erosion is calculated using a typical Finnie-Bitter model [1]. In this paper, two categories of near wall modeling approaches (wall functions and near wall models) are presented and examined. Erosion Prediction results for 300 μm large particles and 25 μm small particles are compared with experimental data to evaluate different near wall models with application to Erosion Prediction. Near wall trajectories are extracted to explain Prediction results and reveal particle near wall behaviors. It is shown that appropriate selection of meshes and near wall models is capable of yielding good Erosion Prediction regardless of particle size.
-
A Comprehensive Erosion Prediction Method for Gas/Liquid/Sand Multiphase Flow
Volume 1: Symposia Parts A and B, 2005Co-Authors: Xianghui Chen, Brenton S. Mclaury, Siamack A. ShiraziAbstract:Sand particles induced Erosion of the piping system and fittings is a concern for many industrial practices. The local flow behavior is one of the primary factors that determine the severity of Erosion as well as the location where the Erosion occurs. Extensive research has been conducted experimentally and numerically to study the Erosion phenomena in single-phase (i.e. gas or liquid) flow systems and a variety of Erosion Prediction models have been developed. Nevertheless, very limited work has been done to investigate the Erosion in multiphase (i.e. gas/liquid) flow systems, which is mainly due to the extreme complexity of the phenomena. A comprehensive procedure is proposed to estimate the Erosion for sand particles entrained in gas/liquid multiphase flow systems. This procedure combines the mechanistic analysis approach and numerical simulation approach. In this procedure, the dominant flow characteristics of a given flow pattern are analyzed and the corresponding representative single-phase flow is proposed. Such that the Erosion problem in this multiphase flow is simplified as one in the representative single-phase to which a single-phase Computational Fluid Dynamics (CFD) based Erosion Prediction model is applied. Meanwhile, the effective sand mass ratio is introduced to reflect the influence of individual flow patterns on the Erosion process by applying a unified mechanistic multiphase flow Prediction model. The calculated Erosion from the single-phase flow weighted by the effective sand mass ratio yields the estimated Erosion for the multiphase flow. Applying this approach, the Erosion in elbows is calculated for bubbly flow, annular and annular-mist flow and slug flow and compared with the experimental data in literature. Agreement between the simulations and the data is reasonable, which indicates that the proposed method is an effective tool to estimate the Erosion in multiphase flow.Copyright © 2005 by ASME
-
application and experimental validation of a computational fluid dynamics cfd based Erosion Prediction model in elbows and plugged tees
Computers & Fluids, 2004Co-Authors: Xianghui Chen, Brenton S. Mclaury, Siamack A. ShiraziAbstract:Abstract This paper presents a computational fluid dynamics (CFD)-based Erosion Prediction model and its application to oilfield geometries specifically elbows and plugged tees. This comprehensive procedure consists of three major components: flow simulation, particle tracking, and Erosion calculation. The effect of the particle rebound model on the particle trajectories as well as Erosion pattern in the elbow and plugged tee is also investigated. Experimental Erosion tests were performed in both an elbow and a plugged tee to evaluate the simulation results. The results from the model show good agreement of the Erosion trend with the Erosion data for elbow and plugged tee geometries. Experiment confirms that a stochastic rebound model is required in simulations to give a reasonable estimate of Erosion rate and pattern in a plugged tee.
William J. Elliot - One of the best experts on this subject based on the ideXlab platform.
-
Enhancements to the Water Erosion Prediction Project (WEPP) for modeling large snow-dominated mountainous forest watersheds
Watershed Management 2015, 2015Co-Authors: Anurag Srivastava, William J. Elliot, Erin S. BrooksAbstract:The Water Erosion Prediction Project (WEPP) model, originally developed for hillslope and small watershed applications, simulates complex interactive processes influencing Erosion. Recent incorporations to the model have improved the subsurface hydrology components for forest applications. Incorporation of channel routing has made the WEPP model well suited for large watersheds. However, the model is still limited in modeling forested watersheds where groundwater baseflow is substantial, and where snow accumulation and melt dominate winter hydrology.
-
geospatial application of the water Erosion Prediction project wepp model
Transactions of the ASABE, 2013Co-Authors: Dennis C. Flanagan, James R Frankenberger, Chris S. Renschler, T A Cochrane, William J. ElliotAbstract:Abstract. At the hillslope profile and/or field scale, a simple Windows graphical user interface (GUI) is available to easily specify the slope, soil, and management inputs for application of the USDA Water Erosion Prediction Project (WEPP) model. Likewise, basic small watershed configurations of a few hillslopes and channels can be created and simulated with this GUI. However, as the catchment size increases, the complexity of developing and organizing all WEPP model inputs greatly increases due to the multitude of potential variations in topography, soils, and land management practices. For these types of situations, numerical approaches and special user interfaces have been developed to allow for easier WEPP model setup, utilizing either publicly available or user-specific geospatial information, e.g., digital elevation models (DEMs), geographic information system (GIS) soil data layers, and GIS land use/land cover data layers. We utilize the Topographic Parameterization (TOPAZ) digital landscape analysis tool for channel, watershed, and subcatchment delineation and to derive slope inputs for each of the subcatchment hillslope profiles and channels. A user has the option of specifying a single soil and land management for each subcatchment or utilizing the information in soils and land use/land cover GIS data layers to automatically assign those values for each grid cell. Once WEPP model runs are completed, the output data are analyzed, results interpreted, and maps of spatial soil loss and sediment yields are generated and visualized in a GIS. These procedures have been used within a number of GIS platforms including GeoWEPP, an ArcView/ArcGIS extension that was the first geospatial interface to be developed in 2001. GeoWEPP allows experienced GIS users the ability to import and utilize their own detailed DEM, soil, and/or land use/land cover information or to access publicly available spatial datasets. A web-based GIS system that used MapServer web GIS software for handling and displaying the spatial data and model results was initially released in 2004. Most recently, Google Maps and OpenLayers technologies have been integrated into the web WEPP GIS software to provide significant enhancements. This article discusses in detail the logic and procedures for developing the WEPP model inputs, the various WEPP GIS interfaces, and provides example real-world geospatial WEPP applications. Further work is ongoing in order to expand these tools to allow users to customize their own inputs via the internet and to link the desktop GeoWEPP with the web-based GIS system.
-
Application of the Water Erosion Prediction Project (WEPP) Model to simulate streamflow in a PNW forest watershed
International Symposium on Erosion and Landscape Evolution (ISELE) 18-21 September 2011 Anchorage Alaska, 2011Co-Authors: Anurag Srivastava, William J. Elliot, Mariana Dobre, Emily A. Bruner, Ina Sue MillerAbstract:Assessment of water yields from watersheds into streams and rivers is critical to managing water supply and supporting aquatic life. Surface runoff typically contributes the most to peak discharge of a hydrograph while subsurface flow dominates the falling limb of hydrograph and baseflow contributes to streamflow from shallow unconfined aquifers primarily during the non-rainy season. The Water Erosion Prediction Project (WEPP) model is a physically-based, distributed-parameter, continuous-simulation model. Recent improvements to WEPP include enhanced computation of evapotranspiration (ET) by incorporating the Penman-Monteith method into the model, and improved calculation of subsurface lateral flow by properly setting a restrictive layer and soil anisotropic ratios. These modifications have substantially improved the performance of the WEPP model for forested watersheds. In order to further enhance the model applicability, a baseflow component needs to be incorporated to adequately represent hydrologic conditions where significant quantities of ground water flow to streams.
-
Adapting the Water Erosion Prediction Project (WEPP) model for forest applications
Journal of Hydrology, 2009Co-Authors: Shuhui Dun, Dennis C. Flanagan, William J. Elliot, James R Frankenberger, Peter R. Robichaud, Robert E. BrownAbstract:summary There has been an increasing public concern over forest stream pollution by excessive sedimentation due to natural or human disturbances. Adequate Erosion simulation tools are needed for sound management of forest resources. The Water Erosion Prediction Project (WEPP) watershed model has proved useful in forest applications where Hortonian flow is the major form of runoff, such as modeling Erosion from roads, harvested units, and burned areas by wildfire or prescribed fire. Nevertheless, when used for modeling water flow and sediment discharge from natural forest watersheds where subsurface flow is dominant, WEPP (v2004.7) underestimates these quantities, in particular, the water flow at the watershed outlet.
-
Effects of DEM resolution on forest hydrologic and Erosion Prediction using WEPP
2006 Portland Oregon July 9-12 2006, 2006Co-Authors: Jane Xinxin Zhang, William J. Elliot, Shuhui Dun, Kang-tsung ChangAbstract:The recent modification of WEPP (Water Erosion Prediction Project) has improved the original model’s applicability to hydrology and Erosion modeling in forest watersheds. To generate reliable topographic and hydrologic inputs for the WEPP model, carefully selecting Digital Elevation Models (DEMs) with appropriate resolution and accuracy is essential because topography is a major factor controlling water Erosion. LIght Detection and Ranging (LIDAR), a new remote sensing technology, provides an alternative for generating fine and high-quality DEMs. This study applies WEPP (v2006.201) for hydrological and Erosion simulation under forest conditions and evaluates the effects of DEM resolution and accuracy on watershed hydrology and water Erosion Prediction at a watershed scale. Stream flow and total suspended solids (TSS) in two small forest watersheds located in northern Idaho were collected and processed. A total of six DEMs from three sources (NED, SRTM, and LIDAR) at three resolutions (30 m, 10 m, and 4 m) were obtained and used to calculate topographic parameters as inputs to the WEPP model. WEPP-simulated hydrologic and Erosion results using the six DEMs were compared with the field-observed data. For both study watersheds, DEMs with different resolutions and sources generated varied topographic and hydrologic attributes, which in turn led to significantly different Erosion Predictions by WEPP.