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Special Sessions
Sponsored by the Geomorphology Specialty Group
Association of American Geographers 102nd Annual Meeting
Chicago, Illinois, March 7-11.
Hydrologic modeling of watershed land use/cover change
Paper Session 3658
Thursday, 3/9/06, from 5:00 PM - 6:40 PM
Sponsorship(s):
Geomorphology Specialty Group
Spatial Analysis and Modeling Specialty Group
Water Resources Specialty Group
Organizer(s):
Shixiong Hu, Department of Geography - East Stroudsburg University of PA
Chansheng He - Western Michigan University
Chair(s):
Chansheng He - Western Michigan University
Abstract(s):
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5:00 PM Author(s):
*Chansheng He, Professor - Western Michigan University
Thomas Croley - NOAA Great Lakes Environmental Research Laboratory
Abstract Title: Modeling Dynamics of Nonpoint Source Pollution Loadings in the Saginaw Bay Watersheds by DLBRM
Accurate nonpoint source (NPS) pollution accounting is essential to effective water quality and ecosystem management. The NOAA Great Lakes Environmental Research Laboratory and Western Michigan University are jointly developing a physically based, spatially-distributed hydrology model to simulate spatial and temporal NPS distributions in the Saginaw Bay watersheds. Multiple databases of meteorology, land use, topography, hydrography, soils, and agricultural statistics were used to estimate nonpoint source loading potential in the study watersheds. Soil erosion and sediment yield by water was estimated based on the revised universal soil loss equation (RUSLE). Animal manure production was computed from tabulations of animals by zip code area for the census years of 1987, 1992, 1997, and 2002. Relative chemical loadings for agricultural land use were calculated from county fertilizer and pesticide estimates by crop for the same periods. These estimates are used as the input to the distributed water quality model for simulating pollutant transport through surface and subsurface processes to the Great Lakes waters. Visualization and GIS interfaces are developed to visualize the spatial and temporal distribution of the pollutant transport. These simulations, once verified with the in situ Saginaw Bay water quality data, will provide important information to researchers and decision makers for developing the Environmental Protection Agency mandated Total Maximum Daily Load (TMDL) programs to minimize the nonpoint source pollution in the watersheds.
Keywords: Nonpoint Souce Pollution; Distributed Hydrologic Modeling; Water Quality; Saginaw Bay Watersheds; Great Lakes.
- 5:20 PM Author(s):
*Yong Q Tian - University of Massachusetts-Boston
Ji-Young Kim - Environmental Chemical Corporation, Otis ANGB, Massachusetts
Abstract Title: Up-scaling the hydrological processes in grazing hill lands using Cellular Automata
Animal treading changes land surface soil physical properties, thus representing a potentially important factor in hydrological modeling. In this paper, we present the models developed for assessing the impacts of animal treading on infiltration in animal grazing hill lands. The modeling was conducted in two hierarchical levels in scale: 1) re-modifying the Green & Ampt equation to include the variables on soil, water and animal activities on grazing paddocks at micro scale (0.5 m2) and 2) up-scaling the hydrological processes revealed at micro-scale level for use at a larger area or watershed. The up-scaling model was based on cellular automata approach by considering hydrological interactions between adjacent cells in desired time intervals. The modeling was specified for a single rainfall event on the lands of different topography, soil physical condition,season, and grazing management. The interactions are processes through surface water hydrology, such as velocity, flow volumes and infiltration in corresponding to slope, soil characteristics, inter-track, and track land physical conditions. We examined the up-scaling model in four watersheds with different geomorphology. The modeling results demonstrated great promise at a conceptual level. The study concluded that investigating infiltration processes at micro scale was appropriate to lands with complex grazing patterns and topographic conditions. The up-scaling process has considerable potential for describing spatial and temporal hydrological processes interacting with land, water and animal activities.
Keywords: Cellular Automata, interactive modeling, spatial analysis
- 5:40 PM Author(s):
*Tao Tang, Associate Professor - Buffalo State College(SUNY College at Buffalo)
Abstract Title: Coupling land use/land cover in a GIS distributed watershed model
Challenges exist in GIS based watershed visualization studies. First, large quantity of geospatial data was published, however these datasets were not effectively interpolated in the watershed framework due to lacking in compatibility of field measurements or lacking in visualization models and technologies. Second, studies of spatial quantifications of behaviors and interactions of human, ecosystem factors with landform factors in a drainage basin need to be enhanced. This study demonstrates the spatial modeling of the behaviors and effects of ecosystem and watershed factors, such as human land use activities, slope, and soil type for potential pollution generation and accumulations. GIS spatial analytical tools and distributed model were applied for data integration and visualization. Buffalo River watershed in western New York, in particular the lower Buffalo River watershed of urban land use activities, was used as a study area. USGS 10 meter resolution DEMs were used to delineate the sub-watersheds and river system in the watershed. ArcGIS - ArcHydro module was applied to simulate runoff and pollutant accumulation in the study area incorporating raster, vector, and field water sampling data. Land use classification scheme was developed using Land-Based Classification Standards (LBCS) by American Planning Association (APA). Impervious land uses were computed by relating land use categories to the impervious cover scheme from previous studies. Topological connectivity of factor map layers was established. Weighted effects of influential factors of human land use were computed.
Keywords: watershed, GIS, land use, landform, distributed model
- 6:00 PM Author(s):
*Shixiong Hu, Department of Geography - East Stroudsburg University of PA
Jeffrey W. Hardy,Department of Geography - East Stroudsburg University of PA
Abstract Title: Modeling Hydrological and Geomorphic Processes in Paradise Creek Watershed, PA
The Paradise Creek Watershed is a sub-watershed with an area of 44.5 square miles in the Delaware River Basin. Historically, the high quality water, mountainous forests and low temperatures in the tributaries have provided ideal habitats for cold-water fish. However, human activities and natural forces have caused tremendous changes in this watershed in recent years. Rapid growth, changing land use and development represent a potential for degradation of the entire watershed. This watershed also experienced two 100-year floods during aseven-month period in 2004 and 2005. The GIS-based models (TauDEM, SINMAP, Landserf, and BASINS) are chosen to simulate the hydrological and geomorphic processes. The impacts of recent changes on the nutrients and ecological processes in the watershed are also discussed. Based on remote sensing data and field surveys, preliminary analyses indicate that 1) the land use changes have resulted in a increase in runoff and bank erosion sites; 2) the combination of slope/longitudinal profile, wetness index and stability index is a good indicator for possible bank failure sites; 3) the huge floods destroyed some step-pool systems and dumped tons of sediment in the pools, which impaired the habitat of wild fish greatly; and 4) the rising levels of nutrient loads in the BASINS model simulation agree with the field measurements.
Keywords: watershed processes, hydrological model, bank erosion, and Pennsylvania
- 6:20 PM Author(s):
*T. Edwin Chow University of Michigan-Flint
Abstract Title: Scale Dependence of Rainfall-Runoff Model
Existing rainfall-runoff models can be broadly categorized as spatially invariant (i.e. lumped), spatially variant (i.e. spatially distributed), or a compromise between these two extremes (i.e. semi-distributed or link-lumped). As the geographic scale of input data increases, the spatial heterogeneity accounted within the landscape decreases. Research has shown that this generalization effect of spatial aggregation can affect the accuracy of modeled output. With the emerging use of Geographic Information Science (GISci) technology in coupling with existing stormwater models, spatial scale is undoubtedly one of the most fundamental issues of many researches. The goal of this research was to explore the scale dependence of rainfall-runoff models, including semi-distributed and distributed. This research focused in the two aspects of scale: 1) grid scale (e.g. cell size) and 2) model scale (e.g. number of subwatersheds in a semi-distributed model). A sensitivity analysis was conducted to investigate the impact of scale in modeling hydrologic response. Empirical records from a stream gauge in Columbia, South Carolina validated the estimated runoff hydrographs modeled at various scale. The results showed that the modeled hydrologic response, including peak discharge (Qp) and time to peak (Tp), had a monotonic relationship within the 3 - 20 m range in general. However, the modeled hydrologic response demonstrated greater variability at grid scale beyond 20 m. The results also suggested a positive logarithmic relationship between model scale and modeled hydrologic response. This work provided useful insights in the data acquisition of fine scale spatial data and their interpretation of modeled output.
Keywords: riparian zone, topsoil, heterogeneity, nutrients, nitrogen, phosphorus, gis, interpolation, map, land use, correlation, europe
Session Description: This series of three special paper sessions are co-sponsored by the Coastal and Marine Geography (CoMa) and Geomorphology specialty groups. The research presented in the paper sessions cover a broad spectrum of spatial and temporal scales within aeolian geomorphology.
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