Determining a Method for Targeting Brush Control Through Remote Sensing, GIS, and Hydrologic Modeling

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1 Determining a Method for Targeting Brush Control Through Remote Sensing, GIS, and Hydrologic Modeling Project Duration: March 2003 to February Graduate Student Researcher: Jason D. Afinowicz, Graduate Student, Department of Biological and Agricultural Engineering, Texas A&M University, 210 Scoates Hall, Texas A&M, College Station, TX jason@cora.tamu.edu. phone: (979) Graduate Faculty Advisor: Clyde L. Munster, Ph.D., P.E., Associate Professor, Department of Biological and Agricultural Engineering, Texas A&M University, 210 Scoates Hall, Texas A&M, College Station, TX c-munster@tamu.edu. phone: (979) Problem Statement Encroachment of woody species, most typically mesquite (Prosopis glandulosa) and juniper (Juniperus ashei and Juniperus pinchotii), has dramatically changed the landscape of semi-arid regions due to a host of human and environmental factors (Van Auken, 2000) and is believed to have contributed to the decrease of useful water yield (Wu et al., 2001). Small scale experiments indicate that the removal of juniper species, for instance, may reduce transpiration by as much as 40,000 to 100,000 gallons per acre per year (Owens, 1996). This shortage of water adds additional stress to semiarid systems which operate in a soil-water-deficient manner, meaning that the potential ET rate far exceeds the annual precipitation rate (Wilcox, 2002). Given the rate at which the population of these semi-arid regions is expanding, it is of the utmost importance that efforts are made to minimize wasteful losses of water (TWDB, 2002). It is by this means that brush control has entered the public focus as a possible way to mitigate the problem of reduced water supplies in relatively dry regions. Currently, there is no method for determining regions where the greatest increase in water yield will result from the implementation of brush management practices. Studies that have been conducted tend to focus on a watershed based approach to determine the overall effects of brush control. Research such as this has focused on hydrologic simulation of entire basins to add merit to the cause of brush management, rather than the finer points of implementing these practices (Bednarz at al., 2001; Red River Authority, 2000). This is especially important since Texas has begun the subsidization of these techniques as a way of compensating land owners who make the effort to increase the overall availability of water for a region (TWDB, 2002). If this process of state funded brush control is expected to be economically viable, there must be a way of ensuring that the public funds expended in the name of environmental, agricultural, and anthropocentric well-being are properly spent to rehabilitate locations where the most benefit may be gained. Nature, Scope, and Objectives of the Research Ultimately, research should produce a clear and effective process for targeting brush control projects within an impaired watershed. This project aims to construct the basis upon which this process can be built by combining the use of readily obtainable data and common hydrologic tools to test a process of site selection. The working hypothesis of the research proposes that

2 regions of higher water recovery potential can be recognized, simulated, and confirmed for the implementation of brush management with the use of digital spatial data and techniques. Efforts to evaluate the abilities of GIS and hydrologic models completed prior to the onset of this project demonstrate that the objectives presented are reasonable and attainable with the use of such methods. To complete the goal of this project, this research proposal is written with the following objectives in mind: 1. Create and validate a methodology for recognizing different levels of brush cover from remotely sensed data with readily available digital information and the minimum use of traditional ground survey information. 2. Select candidate brush control sites within the Upper Guadalupe River watershed based on the amount of brush cover, as well as soil, topographic, and climate characteristics. 3. Calibrate and then validate the Soil and Water Assessment Tool (SWAT) with the use of hydrologic data from brush cover studies at the Honey Creek watershed in the Upper Guadalupe River watershed. 4. Use the calibrated model to electronically determine any potential water yield change due to brush removal for the selected sub-watersheds. Creation of a land cover dataset derived from remotely sensed imagery typically requires the acquisition of conventional ground truth data which can be costly and time consuming to collect. To aid in the selection of candidate brush control sites, this research proposes to derive a methodology for creating a coarse land cover set from Landsat 7 Enhanced Thematic Mapper Plus (ETM+) imagery, thorough the use of a classifier trained on the basis of fairly recent Multi- Resolution Land Characteristic (MRLC) that will be suitable for use in hydrologic modeling of candidate watersheds. Detailed information regarding the level of brush cover for both candidate selection and hydrologic modeling will be obtained by overlaying the coarse land cover set with information obtained from digital orthophoto imagery with a very high spatial resolution. The resulting methodology will be validated by GPS survey in the study watershed. Selection of candidate brush control sites will be conducted with the use of the most detailed, readily available data available. In addition to the derived land cover set for selection by brush cover, many other varieties of information will be utilized. Soil depth, which has been identified as a crucial aid in ensuring rainfall reaching the ground permeates the soil and contributes to deep aquifer recharge will be examined with the use of high resolution Soil Survey Geographic (SSURGO) datasets. Topographic analysis of National Elevation Dataset (NED) information will allow the recognition of areas of high slope, which minimizes the opportunity for surface water to be taken up by vegetation. Finally, it is suggested that regions receiving more than 450 mm of rainfall per year will be most likely to benefit from the implementation of brush control (Wilcox, 2002). This climate data will be obtained from Oregon State s Parameterized Regressions on Independent Slopes Model (PRISM), which provides climate data for over 30 years of record. Calibration and validation for the SWAT model will be carried out using data from an inprogress paired watershed study at Honey Creek in the Upper Guadalupe River basin conducted by the USGS, NRCS, and other contributing parties. Information form one of the gauged experimental watersheds in the project will contribute to the calibration of SWAT s overland flow

3 component, which will be verified with data from the remaining watershed. Large scale calibration will be carried out with gauging data for the entire Upper Guadalupe basin. The calibrated and validated SWAT model will then be used to model the watersheds targeted in the selection process to verify the effectiveness of the criteria. The catchments will be simulated with a brush-in-place condition before having the brush electronically removed and simulated again. The difference in water yield and recharge between each simulation will be noted to quantify the effectiveness of brush removal and the ability of the selection criteria. Results Expected from this Project By the combination of novel techniques in remote sensing and the redirection of the focus of previous studies from basin scale processes to small catchment processes, the proposed research aims to produce the critical first step in developing a reliable system for evaluating the level of brush cover and guiding brush management efforts in semi-arid landscapes. Fielding of such a system will considerably aid in the use of brush control to increase water resource availability in these water scarce locations. Future development, beyond the scope of this preliminary phase, can be expected to produce a simple system that may be used by policy makers when deciding where brush control funds are to be spent in order to maximize the sustainability of the range ecosystem and the associated human and agricultural dependency on the range environment. References Bednarz, S.T., T. Dybala, R.S. Muttiah, W. Rosenthal, W.A. Dugas Brush management/water yield feasibility studies for eight watersheds in Texas. Texas Water Resrources Institute, College Station, TX. Owens, M.K The roll of leaf and canopy-level gas exchange in the replacement of Quercus virginiana (Fagaceae) by Juniperus ashei (Cupressaceae) in semiarid savannas. American Journal of Botany. 83: Red River Authority Assessment of Brush Management/Water Yield Feasibility for the Wichita River Watershed Above Lake Kemp, Hydrologic Evaluation and Feasibility Study. Red River Authority of Texas. Wichita Falls, TX. TWDB Water for Texas Texas Water Development Board, Austin, TX. Van Auken, O.W Shrub invasions of North American semiarid grasslands. Annual Review of Ecology and Systematics. 31: Wilcox, B.P Shrub control and streamflow on rangelands: A process based viewpoint. Journal of Range Management. 55: Wu, X.B., E.J. Redeker, and T.L. Thurow Vegetation and water yield dynamics in an Edwards Plateau watershed. Journal of Range Management. 54:

4 Vita J.D. Afinowicz EDUCATION: 2002 B.S. in Agricultural Engineering. Department of Biological and Agricultural Engineering, Texas A&M University. CERTIFICATION: Engineer In Training (EIT) RESEARCH INTEREST: Hydrology and water policy affecting water quantity issues in rapidly expanding locations of the world with an emphasis on GIS, remote sensing, and other electronic techniques. CURRENT FUNDING: NASA Earth Systems Science Mission to Planet Earth Fellowship (09/01/01 08/31/03) Texas Water Resources Institute Mills Fellowship (09/01/02 08/31/03) PRESENTATIONS: American Geophysical Union Fall Meeting 2002, San Francisco, CA (Scheduled) Using Remote Sensing and GIS Techniques to Identify Watersheds for Brush Control to Maximize Water Yield American Society of Mechanical Engineers Fall Meeting 2001, New York, NY Ethics and Professionalism

5 Clyde L. Munster, Ph.D., P.E. Associate Professor, Agricultural Engineering Department Texas A&M University, College Station, TX Office: (979) / Fax: (979) / c-munster@tamu.edu / Web: Education Ph.D., Biological and Agricultural Engineering, North Carolina State University, Raleigh, NC, M.S.C.E., Civil Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA, B.S.C.E., Civil Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA, Professional Experience Associate Professor, Dept. of Agricultural Engr., Texas A&M University, College Station, TX, 9/98 - present. Assistant Professor, Dept. of Agricultural Engr., Texas A&M University, College Station, TX, 7/92-8/98. Postdoctoral Research Assoc., Biological and Agricultural Engr. Dept., N. C. State U., Raleigh, NC, 2/92-7/92. Research Assist., Biological and Agricultural Engineering Department, N. C. State U., Raleigh, NC, 2/88-1/92. Senior Associate Engineer, Environmental Department, IBM, Research Triangle Park, NC, 5/82-9/87. Graduate Research Assist., Virginia Polytechnic Institute and State University, Blacksburg, VA, 9/80-5/82. Current Grant Funding U.S. Geological Survey (9/1/01 8/31/04) $140,000 Assessing Water Quality Impacts of Nutrient Imports into an Urban Gradient (Lead Investigator with Co-PI s D. Vietor (AGRO) and R. White (AGRO) USDA-CSREES (10/1/01 9/30/04) $384,000 Achieving TMDL Goals in Impaired Watersheds Through Manure Export in Turfgrass Sod (Lead Investigator with Co-PI s D. Vietor (AGRO) and R. White (AGRO), Dr. Feagley (AGRO)) The Higher Education Coordinating Board Advanced Technology Program (ATP) $191,401 Sustainability of Systems for Manure Export and Water Quality Improvements on Impaired Watersheds (Lead Investigator with Co-PI s D. Vietor (AGRO) and R. White (AGRO), A. McFarland (TIAER)) Publications Since 1998 * Indicates a research associate working under the direction of Dr. C. L. Munster Gaudreau, J. E., D. M. Vietor, R. H. White, T. L. Provin and C. L. Munster; Response of turf and quality of water runoff to manure and fertilizer. J. Environ. Qual. 31: (In press). Haby, V. A., C. L. Munster, J. M. Sweeten, A. T. Leonard and J. V. Davis Effects of land-applied poultry lagoon effluent on the environment, 1. Forage production, 2. Nutrient uptake by forage grasses, 3. Soil nutrient levels, 4. Nutrient concentrations in runoff water. Research Center Technical Report No. 98-1: Sung,* K., M. Y. Corapcioglu, M. C. Drew and C. L. Munster Plant contamination by organic pollutant in phytoremediation, J. Environ. Qual. 30: (2001). Sung,* K., C. L. Munster, R. Rhykerd*, M. C. Drew and M. Y. Corapcioglu The use of box lysimeters with freshly contaminated soils to study the phytoremediation of recalcitrant organic contaminates, Environ. Sci. Technol. 36, Sung,* K., C. L. Munster, R. Rhykerd*, M. C. Drew and M. Y. Corapcioglu The use of vegetation to remediate soil freshly contaminated by recalcitrant contaminates. Water Research. In review. Sung,* K., J. Kim, M. Y. Corapcioglu, C. L. Munster, S. Park and M. C. Drew Microbial biomass in the rhizosphere: model development and column experiments. Plant and Soil. In review.

6 Sung,* K., C. L. Munster, M. Y. Corapcioglu, R. Rhykerd*, S. Park and M. C. Drew Phytoremediation and modeling of land contaminated by hydrocarbons using Eastern Gamagrass and annual ryegrass. Transactions of the ASAE. In review. Sung,* K., M. Y. Corapcioglu, C. L. Munster and M. C. Drew Modeling plant contamination during phytoremediation. Journal of Soil and Sediment Contamination. In review.