EPA Science Inventory





LTHIA is a universal Urban Sprawl analysis tool that is available to all at no charge through the Internet. It estimates impacts on runoff, recharge and nonpoint source pollution resulting from past or proposed land use changes. It gives long-term average annual runoff for a land use configuration, based on actual long-term climate data for that area. By using many years of actual climate data in the analysis, L-THIA focuses on the average long-term impact, rather than an extreme year or storm. L-THIA results approximate the relative hydrologic and water quality impacts of different land use scenarios. This information can raise community awareness of potential long-term problems and support physical planning to minimize disturbance of critical areas. It is a convenient tool for screening potential effects of land use change, and to optimize location of a particular land use while minimizing impact on the natural environment. Recent urban sprawl concerns center on several land use change issues. Failure to plan for hydrologic aspects of land use change can result in flooding, stream degradation, erosion, and loss of groundwater supply. L-THIA offers a quick, accessible tool to assess the long-term impacts of land use change. Three versions of L-THIA are currently available. There is a WWW form ("spreadsheet") version, in which the user provides inputs through a simple WWW form. Results in the form of tables, bar charts, and pie charts are produced. There is a WWW GIS version, in which the user has direct GIS functionality in their own WWW browser. This allows them to zoom to the location of interest, create land use maps and obtain mapped LTHIA results within the WWW browser. There is also a GIS version (requiring ArcView) in which the user provides a land use and soil map for the area of interest, so that L-THIA can create a series of output maps. The free web site includes a large amount of background information on running the model, technical descriptions, documentation, interpreting results, case studies and more. It is available at: http://www.ecn.purdue.edu/runoff/lthianew/ Each year URISA ( the Urban and Regional Information System Association) offers the Horwood Critique, with one prize and one honorable mention for the best paper or article on GIS and other decision support tools. On three different occasions peer-reviewed LTHIA papers were judged one of the two best achievements in decisions support that year. 1999 Horwood Critique Honorable Mention Jon M. Harbor; Shilpam Pandey; Bernard A. Engel, Kyoung Jae Lim, Purdue University, West Lafayette IN for An Urban Sprawl Analysis System. A variant of this paper was presented at ORD's National Conference on Tools for Urban Water Resource Management and Protection Proceedings February 7-10, 2000 Chicago, IL It is available online at: http://www.epa.gov/ORD/WebPubs/nctuw/Harbor1.pdf (Further work was the cover story of the Fall 2000 URISA Journal) http://www.urisa.org/store/journal_tocs/Vol12No4toc.pdf 2001 Horwood Critique Honorable Mention - Shilpam Pandey, Jon Harbor, Bernard Engel, Purdue University, West Lafayette, IN Web Based Decision Support Tool for Land Use Planning 2002 Horwood Critique: Honorable Mention Shilpam Pandey, Cornell University, Ithaca, NY Jon Harbor, Jin-Yong Choi, Bernard Engel, Purdue University, West Lafayette, IN Internet Based Planning Decision Support System


LTHIA assesses the long-term Hydrologic impacts of land use change. These includes surface runoff vs. groundwater infiltration, along with quality changes for 14 non-point sources. It does this based upon computations of daily runoff derived from long -term climate records, soil data, current land use and curve number (CN). It requires no detailed data input, as the needed data is directly accessible for most U.S. planning scenarios. LTHIA assesses impacts upon water quality, watersheds, wetlands. It allows automatic optimum siting of commercial, industrial or residential facilities. Land uses automatically addressed include commercial, industrial, residential (several densities) open space, parking/paved, water/wetland, grass/pasture, forest, agriculture, and per cent impermeable. Curve numbers can be customized to express other land uses and Best Management Practices (BMP's). It evaluates areas from a few acres up to hundreds of square miles, or automatically defined watersheds. In addition, the basic LTHIA format allows virtually endless accretion of other geographical databases, including wetlands, floodplain mapping, and demographics (1990 and 2000 censuses). It thus can expand into an almost unlimited succession of planning and design tools covering wellhead protection, feedlot management, ambient air quality, stream hypoxia, and environmental justice. Note the wide range of journals that Bernie Engel and his colleagues have published in: LTHIA Publications - A Partial List Said, A., Stevens, D. and Sehlke, G. Limiting Nutrient and Phosphorus Loading from Non-Point and Point Sources and Groundwater Discharge. Hydrology. In Review Choi, J., Engel, B., Muthukrishnan, S. and Harbor, J., Evaluation of Long-Term Hydrologic Impact for Little Eagle Creek Watershed by Urbanization Using GIS. Journal of the American Water Resources Association. In Review Bhaduri, B., Minner, M., Tatalovich, S. and Harbor, J. Reply to Lantz and Hawkins' discussion of 'Long-term hydrologic impact of land use change: A tale of two models.' Jnl. Water Resources Planning and Management. Accepted Choi, J., Engel, B., Kim, Y., Bhaduri, B. and Harbor, J., Development of the Long Term Hydrologic Impact Assessment (LTHIA) WWW Systems. In: Stott, D., Mohtar, R. and Steinhardt, G. (Eds.), Sustaining the Global Farm, selected papers from the 1999 ISCO meeting. p.1018-1023. In Press. Choi, J., Engel, B. and Harbor, J., GIS and Web-based DSS for Preliminary TMDL Development. TMDL Conference Proceedings, American Society of Agricultural Engineers. In Press. Bhaduri, B., Minner, M., Tatalovich, S. and Harbor, J. Long-term hydrologic impact of land use change: A tale of two models. Journal of Water Resources Planning and Management, 127(1), p.13-19. 2001. Pandey, S., Harbor J., Engel B., A Web-Based Tool to Assess Impacts of Land Use Change. Urban and Regional Information Systems Association, Annual Conference Proceedings. 2001. Choi, J. Y., B. A. Engel, S. Pandey, J. Harbor, Web based DSS for Evaluation of Hydrological Impact by Urban Sprawl, 2001 ASAE Annual International Meeting, Sacramento, California, Paper No, 012026, 2001. Pandey S., Lim K.J., Harbor J., Engel B., Assessing the long-term hydrologic impact of land use change - A practical Geographic Information System (GIS) based approach . In: Singh, R. (Ed.), Urban sustainability in the context of Global Change. Science Publishers, Inc., Enfield, New Hampshire. p. 247-259. 2001. Grove, M., Harbor, J., Engel, B. and Muthukrishnan, S. Impacts of Urbanization on Surface Hydrology, Little Eagle Creek, Indiana, and Analysis of LTHIA Model Sensitivity to Data Resolution. Physical Geography, 22, p.135-153. 2001. Harbor, J., Engel, B., Jones, D., Pandey, S., Lim, K. and Muthukrishnan, S., A Comparison of the Long-Term Hydrological Impacts of Urban Renewal versus Urban Sprawl. National Conference on Tools for Urban Water Resource Management & Protection, Environmental Prote

Record Details:

Completion Date: 12/01/2005
Record Last Revised: 01/24/2006
Record Created: 10/27/2005
Record Released: 10/27/2005
OMB Category: Other
Record ID: 143157