The Use of Geographic Information System Images as
a Tool
to Educate Local Officials about the Land Use - Water Quality
Connection
Chester L. Arnold and Heather M. Crawford
Sea Grant
Marine Advisory Program, University of Connecticut
Roy
F. Jeffrey and C. James Gibbons
University of Connecticut Cooperative
Extension System
Introduction
Land use management is the key to improving water quality. This is particularly true for nonpoint source pollution, which cannot be controlled solely with standard regulatory permitting and enforcement techniques.In the United States, land use decisions are made primarily at the local level, by elected, professional, or volunteer municipal officials. Because the cumulative water quality impacts of these local decisions can be enormous, educating municipal officials about the relationship of land use to water quality is a critical step toward the goal of effective watershed management.
The current proliferation of laws, regulations, and technical guidance directed toward management of nonpoint source pollution will further increase the need for education. As this wave of information cascades from federal to state to local agencies, the task of making this material understandable, or at least accessible, to municipal implementers becomes ever more important. Relevant to this task are two challenges associated with educating local volunteer decision makers: 1) the limited time that most people can devote to any one issue (such as water quality) in the course of their routine duties, and 2) the high membership turnover rate typical of municipal commissions.
This paper describes an ongoing pilot project in Connecticut, the Nonpoint Education for Municipal Officials (NEMO) project, whose purpose is to develop and test one method of dealing with the educational challenge outlined above. The NEMO Project is being used to explore the use of geographic information system (GIS) technology as a tool to educate local officials about the links between land use and water quality.
Project Background
NEMO is a project funded by the U.S. Department of Agriculture (USDA) - Extension Service as part of a national USDA water quality initiative. NEMO and a few sister projects in the Northeast have been funded in an effort to support the National Estuary Program (NEP) sponsored by USEPA. NEP projects are federal-state partnerships whose goal is to research, characterize, and assemble management plans to address key environmental problems threatening estuaries of national importance. In virtually all of the estuaries being studied throughout the country, nonpoint source pollution has been identified as a major problem, and Long Island Sound, the focus of NEMO, is no exception.NEMO is an outgrowth of several ongoing projects of the Connecticut Cooperative Extension System (CES). CES staff are working on water quality and natural resource planning issues. As part of the Sea Grant Marine Advisory Program (a cooperative venture between CES and the Connecticut Sea Grant College Program), additional staff are working on similar issues along the coast. CES and Sea Grant involvement with the Long Island Sound (NEP) Study provided the impetus for the creation of NEMO.
As part of the work done under the auspices of the Long Island Sound Study Nonpoint Source Working Group, Dr. Dan Civco, of the University of Connecticut Natural Resources Management and Engineering Laboratory for Earth Resources Information Systems, conducted remote-sensing research resulting in a land cover map for the entire state of Connecticut. Satellite images were analyzed for land cover (principally derived from the reflectivity of the land) and the data have been incorporated into a GIS. The land cover information is being used in the Long Island Sound Study as input to an effort to rank watersheds according to their nitrogen export to the Sound.
CES and Sea Grant staff involved with this aspect of the Long Island Sound Study realized that the educational potential of the GIS land cover information was at least as great as its research value. With support from USDA, the NEMO project team was formed. The team includes CES staff with water quality and natural resource planning expertise, CES and Sea Grant staff with water quality and coastal zone management expertise, Dr. Civco and his students providing GIS expertise, and Dr. Marilyn Altobello of the University's Department of Agricultural and Resource Economics.
Project Structure
Municipal officials, particularly volunteer commissioners, are the target audience for NEMO. The core of the project is an educational slide presentation based on GIS images (see next section).Two other educational media are being used in support of the slide presentation. A 12-minute educational videotape is used to introduce the viewer to nonpoint source pollution problems and solutions. The video, a cooperative effort between NEMO and the New York Sea Grant Extension Program, was made both as part of the introductory section of the core NEMO presentation for municipal officials, and with an eye to wider use for general audiences. A series of fact sheets is being written to provide more detailed information corresponding to the topics covered in the slide presentation. The fact sheets cover nonpoint source issues and management techniques and are organized by land use type (see section below on project publications).
NEMO is being applied initially in three pilot areas. Because of the way land use decisions are made in Connecticut, the project team decided to work at the town level. Connecticut has no regional or county government, and, like much of New England, municipal "home rule" is strong. As explained in the next section, this municipal orientation does not preclude a watershed-based approach.
In order to get a wide range of experience in the applicability and usefulness of the program, the team chose towns that differed in three important characteristics: the degree of development, the type of water pollution problem of local concern, and the complexity and sophistication of town governance. A common criterion was a desire on the part of the chief elected official or town planner to participate in the project. Interest in the project was high. Although the project was not publicized, word-of-mouth news about it resulted in more towns "applying" for inclusion in the project than could be accommodated.
After working with two towns in eastern and central Connecticut (Waterford and Old Saybrook), NEMO project staff decided to choose a small watershed in western Connecticut shared between two towns (Fairfield and Westport) as the third pilot area. CES and Sea Grant are conducting this third pilot effort jointly with the USDA Soil Conservation Service (SCS), which has been doing an extensive GIS analysis of the watershed.
GIS as an Educational Tool
Geographic information systems allow geographically referenced data to be manipulated, analyzed, and displayed in ways that would be prohibitively time-consuming (or impossible) using conventional maps and overlays. Because of this, GIS is rapidly becoming an invaluable management and planning tool in a wide range of professions. GIS is often used for natural resource management applications at the national, regional, and state levels. At the local level, GIS, where used at all, seems to be reserved primarily for demographic and logistic applications, such as tracking property transactions or determining optimal bus routes. In many cases, GIS has been tried at the local level and then abandoned as expensive, overly complicated, and personnel-intensive.Although NEMO is based upon digitized natural resource information, it is used not so much with a planning emphasis, but as a highly effective visual tool to help non-technical citizen volunteers intuitively understand the relationship of land use to water quality in their town. It is important to note that we are not advocating adoption of GIS technology by the target towns, nor is our degree of GIS sophistication very great. While the project relies heavily on the GIS expertise of Dr. Civco and his students, all NEMO Project work is done with personal computers (as opposed to the more powerful work station environment typical of GIS work).
The land cover data developed by Dr. Civco is the primary source of NEMO project GIS images, but other data layers are used as well. These data layers are procured from town, state, and regional planning agencies. To date, the project team has been lucky in that almost all of the data necessary to the program has been available already digitized. For Waterford, hydrography, roadways, soils, topography, and town zoning data are being used. It is anticipated that a different set of layers may be used for each town, depending on availability and the problems at hand.
One general comment: GIS technology poses pitfalls, as well as opportunities, for educational programs. The powerful and colorful imagery creates a desire to use complicated, multi-layer images, simply because you can. Our feeling is that these "GIS pizzas" are probably more effective as modern art than as educational tools. Based on this intuition and our experience working with municipal commissions, our tendency has been to continually simplify the GIS images and shorten the slide presentation. The core NEMO presentation described in the following section now runs about 60 minutes.
The NEMO Presentation
The core NEMO presentation can be roughly divided into five parts. The first part makes use of the project videotape to introduce the audience to nonpoint source pollution: causes, effects, and management. The emphasis is on the need to change both personal behaviors and municipal policies and decision-making criteria. In addition to the video, new federal and state nonpoint source laws (stormwater management, coastal nonpoint program) are briefly reviewed to emphasize the need for towns to get up to speed on this issue. GIS is described in general terms.The second part of the presentation focuses on water quality and watersheds. Regional (Long Island Sound) water quality issues are mentioned, but the emphasis is on local water quality problems, both current and historical. To the extent possible, these are shown on a GIS map of the town. Examples of each major type of nonpoint source pollution (pathogens, nutrients, toxic contaminants, sediment, and debris) are illustrated with local photographs. Following the water quality discussion, hydrologic cycle and watershed concepts are introduced. It is here that the project makes the first real use of GIS technology -- town and regional hydrography, drainage basin boundaries, and topography are used to show how and why water systems are connected. The initial reaction of the NEMO team and other observers is that these three-dimensional images are very effective in communicating the concept of watersheds and the need for watershed management.
The third section of the NEMO presentation focuses on land cover and land use. The original satellite photography and its resultant land cover analysis (23 land cover categories) are shown and explained. Although, in general, the program does not explain the technical background or analytical techniques behind the GIS data, the difference between land cover (derived by reflectivity from what is seen by the satellite) and land use (actual use or what is zoned or planned for a given area) is explained.
The 23 land cover categories are then condensed into six basic land cover categories approximating traditional land use types with which municipal commissioners are familiar: 1) commercial and industrial land, 2) water, 3) roadways, 4) residential land, 5) agricultural and open land, and 6) forested and wetland areas. GIS images of the town highlighting each of these cover types are inset into corresponding local photographs, and followed by word slides summarizing characteristic nonpoint source problems associated with each land cover category. More detailed information on these topics is contained in NEMO fact sheets (see section below on project publications).
The fourth part of the NEMO presentation focuses on impervious surfaces (see Figure 1). A growing body of evidence suggests that there is a direct relationship between the amount of impervious surface in a given watershed and the impairment of water quality in the receiving stream of that watershed (Klein, 1979; Griffin et al., 1980; Schueler, 1987; Schueler, 1992; Schueler et al., 1992; Booth and Reinfelt, 1993). Existing land cover (the six-category GIS information) is used as the basis for estimating the present degree of imperviousness of watersheds draining to key town water resources, such as a coastal cove or a reservoir. A "build-out" analysis of imperviousness is performed based on the zoning regulations of the town, assuming a scenario of 100% development to zoning specifications (for instance, that all land zoned as residential will be developed as such). The analysis is applied only to land available and suitable for development. All dedicated open space, wetlands, and other non-developable areas are excluded from the build-out scenario. The estimates of current and future levels of imperviousness are calculated and displayed by watershed, which we believe is the most appropriate and useful way to consider the implications of the data.
It is not within our capabilities at present to estimate amounts of impervious surface directly from the satellite-derived land cover data. Therefore, both current and future estimates use literature values for the percent imperviousness of given land use types, using the land cover data and the zoning regulations, respectively, as the basis for applying these values.
By showing which watersheds, and which sub-basins within the watersheds, are likely to experience dramatic increases in impervious surface area, the NEMO presentation allows local officials a "quick and dirty" look at the present and future effects that their land use plans and policies might have on local water resources. Based on this information, the project team can suggest alternative strategies in the fifth and final portion of the program. Emphasis is placed on a three-tiered strategy of: 1) planning development based on natural resources; 2) minimizing impacts through site design; and 3) mitigating unavoidable impacts through the use of best management practices.
These strategies are covered in greater detail in the NEMO fact sheets which, in turn, contain reference lists. It should be noted that the NEMO project team members do not act as consultants or offer specific solutions. However, detailed follow-up seminars on such topics as natural resource inventories or best management practices are made available to interested commissions, and hard copies of key GIS images and analyses are left with the towns for future use.
The NEMO project emphasis on impervious surface is admittedly simplistic. NEMO is an educational program and is not designed to take the place of technical guidance. However, it is our hope that the simple yet scientifically valid relationship between impervious surface and water quality can be used as an underlying theme which town officials can understand and remember during the course of their day-to-day processing of site development applications. The danger of over-simplification pales in comparison to the danger that, faced with an avalanche of technical guidance and regulations from an army of agencies, local officials will be too confused and intimidated to act at all.
Project Status and Future
The initial NEMO presentation has been made to two of the three pilot towns. While the immediate reaction has been very positive in both cases, the project team is continuing to assess the long-term effectiveness of the program in several ways. In one town, the project team is working with the town planner and conservation commission to explore ways to implement an impervious surface "budget" in a key watershed. The pilot program has also led to additional project publications on roadway-related nonpoint source pollution issues and preventative site design elements. One unforeseen result of the pilots has been a number of requests for NEMO presentations from other towns, even given the understanding that the GIS images used would be of the pilot towns. To date, six of these "secondary" presentations have been made, some of which may ultimately bear more fruit than the pilot presentations.Efforts are under way to expand the NEMO model to address different problems and situations. In a follow-up to the Old Saybrook pilot, the project team is working with the regional planning agency to explore ways of integrating surface and ground water nonpoint source pollution protection. In the third pilot project, more accurate land cover data provided by SCS will allow the NEMO Project team to create nitrogen export build-out scenarios and analyze septic failure susceptibility. In addition, a spin-off project in cooperation with The Nature Conservancy is currently under way in the lower Connecticut River area. This watershed-scale project expands the NEMO concept to include GIS analyses and educational programs targeted to wider audiences and focused on other conservation-related topics.
It is difficult to tell whether or not a model project of this type can ultimately contribute to the creation of a program capable of overcoming the twin obstacles of commission turnover and (for lack of a better term) limited attention span for water quality issues. Such a program would need to be simple, inexpensive and easily implemented, yet effective. However, several trends in the GIS industry, including the proliferation of digital natural resource data, the decreasing cost of computer hardware, and the development of user-friendly GIS "browsing" technology (allowing users to manipulate and display existing data sets), make us think that we are heading in the right direction. By retaining our focus on devising an effective educational package, rather than on providing technical guidance or using our GIS capabilities primarily for data analysis, we hope to emerge with a program of practical use to local decision makers which will result in more effective management of nonpoint source pollution.
Project Publications
The NEMO project team is producing a series of 12 fact sheets designed to share information about the project and nonpoint source pollution control with the general public and local officials involved in making land use decisions that may affect water quality. Topics include 1) NEMO project description, 2) nonpoint source water pollution, 3) impacts of development on waterways, 4) strategies for coping with polluted runoff, 5) protecting your town from polluted runoff, 6) asking the right questions about polluted runoff, and polluted runoff and 7) wetlands, 8) agricultural and forested land, 9) residential land, 10) commercial and industrial land, 11) roadways, and 12) growth management. All of the fact sheets will be available by the end of 1994.A NEMO Site Design Booklet including simple sketches illustrating design-related nonpoint source control principles will be available in the fall of 1994.
Luck Isn't Enough is a 12-minute video on nonpoint source pollution suitable for general adult audiences and older students. Examples are taken from Long Island Sound region, but the information is generic and, therefore, applicable for many geographical areas. A totally generic version of the video is currently being produced, with special funding from USEPA.
For Further Information
Chester L. ArnoldSea Grant Marine Advisory Program, University of Connecticut
43 Marne Street, Hamden, CT 06514
Tel: 203-789-7865, Fax: 203-789-6461.
References
Booth, Derek B. and Lorin E. Reinfelt. 1994. Consequences of Urbanization on Aquatic Systems -- Measured Effects, Degradation Thresholds, and Corrective Strategies. In: Proceedings of the Watershed '93 Conference
Griffin, D.M. et al. 1980. Analysis of Non-Point Pollution Export
from Small Catchments, Journal of the Water Pollution Control
Federation
Klein, R. D. 1979. Urbanization and stream quality impairment,
Water Resources Bulletin 15(4): 948-963.
Schueler, T. R. 1987. Controlling Urban Runoff: A Practical Manual
for Planning and Designing Urban BMPs. Publication #87703, Washington
Metropolitan Council of Governments, Washington, DC. 275 pp.
Schueler, T. R. 1992. Mitigating the Adverse Impacts of Urbanization
on Streams: A Comprehensive Strategy for Local Government. In:
P. Kumble and T. Schueler (eds). Watershed Restoration Sourcebook:
Collected Papers Presented at the Conference; Restoring Our Home
River: Water Quality and Habitat in the Anacostia
Schueler, T. R. et al. 1992. Developing Effective BMP Systems for
Urban Watersheds. In: P. Kumble and T. Schueler (eds). Watershed
Restoration Sourcebook: Collected Papers Presented at the Conference;
Restoring Our Home River: Water Quality and Habitat in the
Anacostia
This publication addresses the idea of "trading" cleanup efforts
between pollution sources. Trading allows a polluting firm to sponsor
pollution controls elsewhere in a watershed rather than install
controls of its own. Point-nonpoint trading takes place between two
dissimilar firms, a point source involving traceable pollution and a
nonpoint source, producing more diffuse pollution, such as runoff of
agricultural chemicals from cropland. If nonpoint source pollution is
significant and the cost of its control is lower than additional point
source controls, trading may achieve water quality goals at a lower
cost. This analysis provides an initial, empirical assessment of the
feasibility of trading for managing agricultural land use in coastal
watersheds to protect water quality.
Copies may be ordered (refer to AER-674) from: ERS-NASS, 341 Victory
Dr., Herndon, VA 22070, Tel: 800-999-6779. The cost is $9 (For
non-U.S. addresses, add 25%).
Strategies and policy tools for protecting ground water from pollution
by agricultural chemicals are presented in this manual designed for
local leaders. Topics include: 1) background information on
sustainable agriculture and nonpoint source pollution of ground water
by agriculture and other sources; 2) a strategy for creating Special
Protection Areas for Ground Water and Sustainable Agriculture; 3)
citizen participation in community decision making; 4) finding
information; 5) policy tools for protecting ground water and promoting
sustainable agriculture (educational approaches, incentives and
disincentives to voluntary participation, and regulations to reduce
farm chemical pollution of ground water); and 6) identification of
sensitive land.
Copies may be purchased ($15 including postage/ handling) from The
Minnesota Project, 1885 University Ave. W., Suite 315, St. Paul, MN
55104, Tel: 612-645-6159.
In February, 1992, the U.S. Forest Service (USFS) and the
U.S. Environmental Protection Agency (USEPA) held a joint technical
workshop in Corvallis, Oregon, on sediment and water quality. The
meeting was prompted by the increased and widespread perception of
"clean sediment" as a nonpoint source pollutant of significant
ecological concern. There has been an increased focus on the potential
impacts of sediment production from forest management activities on
water quality and aquatic life. Most recently, the impairment of
salmon habitat by sediment has generated increased efforts to
understand the influences of forest management activities. In response
to these trends, USEPA and USFS have begun to work together to explore
possible approaches to address clean sediment problems and to clarify
technical methodologies and concerns.
The primary objectives of the Corvallis workshop were to review the
results of existing research and to build on these previous efforts by
identifying opportunities for technology transfer and by developing a
research agenda to address identified gaps in existing
knowledge. Panels and discussions addressed four topics: 1) sediment
production and transport processes; 2) land and riparian zone
interactions with sediment; 3) sediment production by activities
related to forest uses; and 4) sediment impacts on aquatic
life. Future research needs in each area were identified.
Copies ($12.95, including postage and handling) may be ordered from
Veronica Lee, Publications, The Terrene Institute, 1717 K Street, NW,
Suite 801, Washington, DC 20006, Tel: 202-833-8317, Fax:
202-296-4071.INFORMATION
Point-Nonpoint Source Trading for Managing Agricultural Pollutant
Loadings:
Prospects for Coastal WatershedsGround Water Protection Strategies
Technical Workshop on Sediments - Proceedings