1. Introduction
The need for energy has encouraged the exploitation of coal mines around the world. Extensive mining has made great contributions to the energy industry in the past. At the same time, however, extraction of coal has caused serious environmental problems, particularly as a result of mining. Typically, when all the coal had been mined from a site, that site was abandoned. As a result, in 1977 there were an estimated 1.1 million acres of abandoned surface coal mine sites in the United States.

The surface mining activities in the South Fork of the Patoka River watershed, in Indiana, were extensive, and they have been dominant economic influences for the past 60 years. However, according to Indiana Department of Natural Resources (IDNR), many of these abandoned mine sites have become major pollution sources of Indiana soil and waterways. Some parts of the South Fork of the Patoka River have been severely polluted and the ecosystem has been greatly damaged. As this process continues, the surrounding living environments become progressively more hostile to habitation. To prevent further pollution of this watershed, reclamation of the abandoned sites has become increasingly necessary. In 1977 the "Surface Mining Control and Reclamation Act" was passed by Congress to regulate the mining industry, and to address the problem of abandoned mine sites.

Today, Geographic Information System (GIS) is a mature technology used to store, to manage, and to analyze large amounts of environmental data. But it still lacks the capability to support sound decision-making XXX. To support spatial decision making effectively, GIS tools should be accompanied by models for analysis and decision support, which are developed in the spatial and management sciences. In recent years a number of studies have focused on the role of spatial information systems in facilitating more understandable and environmentally friendly planning. Special attention has been given to the potential use of GIS when combined with Multi-Criteria Analysis (MCA) techniques in environmental management (Fedra and Reitsma, 1990; Schaller, 1990; Pereira and Duckstein, 1993; Jankowski, 1995). A Spatial Decision Support System (SDSS) applies rules for the processing of information from a GIS database to model, and therefore to generate alternatives for decision-making. Abandoned coal mine reclamation planning is a process of decision-making, as many variables have to be taken into consideration. The strategies are usually generated by comparing alternatives created by applying different scoring schema or sets of criteria to the relevant variables. The purpose of this study is to develop a SDSS that will integrate GIS with complementary models, using image processing techniques and Multi-Criteria Decision-Making (MCDM) methods in order to aid in implementing a reclamation plan. In particular, the system devised in this study could support coal mine reclamation planXXX for the South Fork Patoka river watershed based on given environmental variables and requirements.

The objective of this study was to develop an approach for decision-making in abandoned land reclamation, not only for the South Fork Patoka river watershed area, but for other damaged sites, such as those associated with abandoned metal mines, hazardous wastes, and oil wells. This method will help those users with little knowledge of GIS/MCDM/SDSS to make good decisions.
[Xiao Liu:  You're asking the reader to remember quite a lot here, with this multiple acronym.]

The approach in this study was based on the assumption that GIS/MCDM/SDSS can improve the quality of decision-making primarily by offering an interactive environment for analysis, provided that this environment is also suitable for users who do not have knowledge of the analytic techniques employed. The spatial decision support system (SDSS) will assist decision-makers in the planning process to select from the alternatives by comparing XXX priority maps.

Hypothesis

Unlike traditional hypothesis based research, which could be tested objectively by field study, this study was focused on developing the methodology or prototype for coal mine reclamation planning using advanced techniques. It can be evaluated by users or experts in the coal mine reclamation area.

The main purpose of this study was to integrate GIS, modeling, image processing, and multi-criteria decision-making analysis into a spatial decision support system to provide support for decision-makers in reclamation planning. The integration of digital data sources, environmental modeling, and multi-criteria analysis in a computerized environment could produce models of the abandoned coal mine lands that are applicable to reclamation problems.  It was expected that better reclamation practice will result from applying the system in those areas with disturbed land.

The aim of this research is:

Study Area

The South Fork of the Patoka River watershed (Figure 1-1) is located in southwestern Indiana. It covers part of Pike County, with small remnants in neighboring Gibson and Warrick counties.  The total watershed area is approximately 50 square miles, which covers parts of four 1:24,000 USGS topographic maps (Oakland City, Augusta, Lynnville, and Folsomville). This area has been severely affected by surface mining. The surface mining area is approximately 22 square miles, or almost 45% of the total watershed. Farm lands and forest stands comprise the remaining area.

General Nature

"The parent material of the soils in this watershed consists of alluvial, lacustrine, glacial, and windblown deposits; material weathered from sandstone, silt-stone, shale, or limestone; and an overburden from surface mining" (Soil Conservation Service, 1987). The climate in Pike County is cool and humid. It is cold in winter and rather hot in summer. In winter the average temperature is 34 degrees F; in summer the average temperature is 76 degrees F. The total annual precipitation is 43.62 inches. The average snowfall is about 9 inches and the relative humidity in mid afternoon is about 60 percent (Soil Conservation Service, 1987).

Farming is the main land use in Pike County. Slightly more than half of the county is farmland. The major crops are corn, soybeans, and wheat. Coal mining is a major industry other than farming. Strip mining takes several hundred acres per year out of farm production. The coal mining was originally shaft mining, which employed large numbers of people. But in recent years it has been replaced by strip mining, which resulted in a marked decrease in the necessary work force. The population of Pike County reached its peak in 1900, when it was 20,846. It was 12,281 in 1970 (ISPSA, 1979) and 13,465 in 1980 (US Bureau of Census, 1981). In 1996 it was 12,785.

The processes involved in surface mining in this area have a dramatic impact on the soils. Surface mining begins with a total removal of vegetation, followed by the removal of the soil and bedrock, or overburden, covering the coal seam, then the removal of the coal, and finally the replacement of the overburden. The replaced mixture of soil and shattered bedrock is also known as spoil. The mine spoil consists of highly variable, partially weathered soil and rock material. Fragments of shale, silt-stone, sandstone, and coal comprise about half the volume of the spoil.  The natural soil structure is destroyed by mining activities.

The most common environmental problem associated with coal mining in the Patoka River Watershed is acid mine drainage (AMD). AMD is defined as mine-water runoff with high concentrations of acidity, iron, manganese, aluminum, and suspended solids toxic to aquatic life (Squillace and Dotter, 1990). It is caused when coal seams are mined or opened during road construction and exposed to oxygen. AMD can enter streams as runoff from a point source (mine seep) or from a non-point source (abandoned mine land).

The study area for this research is at the far southern end of the watershed of the headwaters, just around the border of Pike County and Warrick County (Figure 1-2). A major landmark for this area is the Log Creek Church. This area contains several abandoned mining sites (Figure 1-3) that have been mined during different time periods from 1921 to 1982. Little reclamation action has been done  concerning revegetating the abandoned lands. After decades of mining, this area has generated pollution problems for the entire watershed. The primary problem associated with older mines in this area is acidity, with some mines experiencing extremely acid "hot spots" high in sulfur (Soil Conservation Service, 1987).  Carried by water, the acid materials run into main streams and produce severe acid drainage into the South Fork and other streams. The Patoka South Fork Watershed Steering Committee (PSFWSC) has been monitoring the water quality on Log Creek for the past year. The sample data (Table 1-1) obtained from the site (Figure 1-4) indicate that Log Creek has been severely affected. It is very apparent that Log Creek accepts water flows with acidity from surrounding areas as it extends into abandoned mining areas. Since the Reclamation Act took effect in 1972, several reclamation projects have been planned in this area to recover the damaged land.

 

 

Soils

The major soil series in the study area are Fairpoint, Bethesda, Zanesville and a small amount of Gilpin. Fairpoint and Bethesda soils seem to appear mixed as mine spoil in surface-mined area, while Zanesville and Gilpin occur on uplands near the mining area.  Fairpoint and Bethesda are both in the family of loamy-skeletal, mixed mesic Typic Uorthents. Fairpoint is non-acidic and Bethesda is acidic. These soils formed in a regolith in surface-mined areas on uplands. They consist of deep, well drained, and moderately slowly permeable soils. Slopes range from 0 to 70 [degrees? percent? other?  I think you should include some units here.]for Fairpoint, and they range from 8 to70 [Ditto]for Bethesda. Typical Fairpoint and Bethesda soils are not well developed, and only have a thin "A" horizon and a thick "C" horizon. In the 3 inch "A" horizon, the fragment contents account for about 0 to 15 percent; the organic matter content is very low in the surface layer. In the "C" horizon the contents account for 10 to 30 percent. Because of the slope, the rock fragment, and the restricted permeability, these soils are generally not suitable for crops or for construction. Most areas are used for growing hay, for pasture or for woodland (SCS, 1987).

Zanesville series belongs to the family of fine-silty, mixed, mesic Typic Fragudalfs. This series of soils is well developed. It consists of deep, moderately well drained soils with fragipan on ridges and side slopes in the uplands. These soils formed in 2 to 4 feet of loess and in the underlying material that was weathered from acid sandstone, siltstone, and shale. Because of the location, some are severely eroded. Slopes range from 2 to 18 percent. Permeability is moderate above the fragipan and slow in the fragipan. The depth to fragipan is 20 to 32 inches. Low slope Zanseville soils are well suited to corn, soybeans, and small grain. In general, the wetness and restricted permeability limit its usefulness for construction. Most areas are used for crops, hay and pasture, and a few are wooded, depending on the slope.

Gilpin series is in the family of fine-loamy, mixed, mesic Typic Hapludalfs. It consists of moderately deep, well drained, moderately permeable soil in the uplands, formed of material weathered from sandstone, siltstone, and shale. Slopes range from 15 to 50 percent. The depth to rippable bedrock is 20 to 40 inches. The coarse fragment content in the surface soil is about 5 percent, and it increases with depth along the profile. Most areas of moderate slopes are wooded, and those of high slopes are pastured. Because of the steepness and depth to bedrock, these soils are generally unsuitable for construction and recreation. Gilpin soils account for only a small part of the soil in the study area.

 
Table 1-1. pH Values of Water Sample on Log Creek for 1998
(From Patoka South Fork Watershed Steering Committee (PSFWSC))
Date 0103 0218 0311 0407 0504 0618 0714 0818 0922 1023 1120
pH 3.0 4.7 4.8 3.0 3.2 5.6 5.8 5.0 4.1 3.3 4.0
 

Mining History

Coal mining began in Indiana in the middle 1800's using the underground mining method. As a consequence, abandoned underground coal mines underlay extensive areas of Indiana. By the early 1900's, through the development of steam-powered equipment, surface mining soon became the dominant method of coal removal in the State.

Large-scale surface mining operations began in this area as early as 1926, shortly after the end of World War I. With improvements in mining technology early in the 20th century, the extent of lands given to coal extraction through both deep and surface mining techniques increased dramatically, leading to the disturbance of a significant percentage of the area’s soil and vegetation.

In 1926, Indiana coal mine operators pioneered surface mined land reclamation in the United States when a few of them joined together to form the Indiana Coal Producers Association. They voluntarily decided to revegetate parts of their spoil banks (which were piles of removed rock and soils) through reforestation to either obtain a cash crop or to hide the spoil. Not all early mine operators joined the association; therefore, reclamation remained sporadic. As a result, the State of Indiana passed a law, in 1941, requiring the planting of trees on spoil banks. Indiana was the second state in the nation to implement a reclamation law. Prior to 1967, the spoil was simply used to fill in trenches from which the coal had been removed as the mining operation proceeded across the landscape. The abandoned spoil formed steep sided ridges on which trees were generally planted. By 1967, the Indiana law had realized a major revision including: provisions for the planting of farm crops, hay and grasses on mined land; requirements that certain acid-forming rocks and other materials be buried; and, areas reclaimed for agriculture were to be accessible by farm machinery. In addition, operators had to do advanced planning for use of the land after mining was completed. Standards were established for the creation of lakes and the leveling of peaks and ridges caused by rock and soil removal. It was the first law in the nation to require rules for grading mined land to specific contours. Performance bonds placed on the land to be mined were held until reclamation was completed and the revegetation was successful.

After the adoption of federal law in 1977, the reclamation began by replacing topsoil and planting grasses on the sites. From 1982 through 1997, more than 60 million dollars have been spent in Indiana by the Indiana Division of Natural Resources (IDNR)/Department of Reclamation, correcting more than 300 sites.

Impact of Surface Mining

Coal mine sites pose specific environmental problems that need to be addressed in a systematic manner. The primary negative impacts associated with coal surface mining are the accelerated erosion induced by a loss of vegetative cover and the leaching of elements from the mine spoil.

According to the National Coalition of Abandoned Mine Reclamation (NCAMR), the effects on the environment may be categorized under the following six headings:

    1. Water Quality Problems
Acid run-off and sedimentation from abandoned mine sites contaminate thousands of miles of streams and water tables that border them nationwide. This contaminated water eventually serves as the municipal water supply for many citizens in both rural and urban areas. Therefore, water treatment costs extend far beyond the mined land boundaries. Acid mine drainage also leads to increased road maintenance costs, due to the corrosive effects of this drainage on culverts.

Water that is discharged from mining or mine-related operations contains high levels of dissolved iron and aluminum sulfates in conjunction with pH values less than 4.5 (acidic). It is produced when oxygen dissolved in water reacts with pyretic (iron sulfide) materials found in association with most coal deposits. Acid mine drainage (AMD) degrades the water quality of streams and water supplies, often to the point of eliminating all biological activity within the stream so contaminated.

    1. Soil Contamination
    2. Mining activities disturb the original soil profiles. Both chemical and physical properties are altered. As coal is removed from the soil, fragments of shale, silt-stone, sandstone, and coal are left over and form so-called mine spoil. Acid sedimentation carried by water from abandoned mine sites accumulate in lower areas and contaminate the soil.
       

    3. Clogged Streams
    4. Streams and drainage systems are often clogged by sedimentation from abandoned mine sites. Such streams become filled with silt and sedimentation debris carried downstream by surface run-off from these abandoned mine lands. The resulting sedimentation often causes a blockage of the stream, resulting in the flooding of roads and/or residential and public properties.
       

    5. Health & Safety problems
    6. Abandoned mine sites have contributed to many deaths in several states. Children seem to be drawn to these sites, because they see them not as dangerous areas but as interesting places to play and to explore. High walls, open shafts, dilapidated mine structures, and water-filled pits present serious health and safety threats. These sites are sometimes within easy walking distance from schools and subdivisions and can become deadly play areas.
       

    7. Economic Problems
    8. These lands are often located in the most economically depressed areas of our nation. Cities and towns in these areas often thrived during the period of active mining but were then frequently abandoned when the mining activity slowed or halted. All that remains in many once populated mining communities are scarred lands and a few residents who were willing to commute to larger cities for employment. These areas are in desperate need of new industries to replace the jobs that the coal mining industry once provided. But, the mine sites, as they presently exist, make it nearly impossible for these communities to compete for industry and tourism.
       

    9. Esthetic Problems
Abandoned mine sites with sparse, or no, vegetation, and with stagnant water pools--often used as illegal trash dumps--have a negative effect on all viewers, local and non-resident alike. The appearance of the sites and their proximity to public lands often depresses land values and detracts from tax bases. Such environmental scars contribute to a loss of community pride; people become apathetic toward the conditions in these areas. It is important to note that the spread of debris, from erosion, and of pollutants from the mines, are often linked by the running water that transports them. In addition, mining activities leave soils unsuitable for most types of vegetation. Problems associated with these soils are physical, nutritional, and toxic.

The impact of mining activities varies dramatically within the watershed. According to the data collected monthly by the Patoka South Fork Watershed Steering Committee (PSFWSC) to monitor the water quality, the pH typically ranges from 3.0 to 7.0 at various points. The sites with low pH have an urgent need for reclamation of the strip of surface mine areas causing the problem in order to prevent further pollution.

Abandoned Coal Mine Reclamation

As abandoned coal mines have been degrading environmental quality with increasing intensity, reclamation has become more necessary. The major goal of reclamation is to restore the land, water and air environments that have been degraded by the adverse effects of past coal mining practices. Potential solutions include measures for the conservation and development of soil, water, woodland, fish, wildlife, recreation, and agricultural resources.

Potential benefits from the reclamation of abandoned mine lands include: protection of life, health, and safety; improvement of environmental and social conditions; and better use of natural resources.

Several abandoned mine sites in this study area create conditions hazardous to human health, safety, and property. The abandoned mine drainage sources upstream of water supply intakes and the dangers inherent in high walls and pits near roads were addressed.

Many of the abandoned mines in this study have caused environmental and aesthetic problems as well. These conditions lead to extreme land and water erosion and pollution damage. The benefits that can be derived from eliminating problems are many and varied.

Land oriented potential benefits of this study include improved hunting and recreation areas, improved environmental aesthetics, enhanced timber production, improved land quality for agriculture, and increased land values.

Water oriented benefits include the evolution of better fishing, the re-establishing of natural stream biota, the attractiveness for non-fishing stream recreation, and the reduction of water treatment costs.

Reclamation of abandoned mines in rural areas, particularly in wild life habitat management areas implemented to encourage the presence of game species, will have a positive impact on hunting. The introduction of game food vegetation, and fringe areas created through the diversity of vegetative replanting, will increase the availability of food to all wildlife while providing an excellent habitat for them. Such reclamation of abandoned mines will enhance not only the wildlife habitat, but also the aesthetic appeal and accessibility it has to hunters.

Farmers will find reclaimed surface mines primarily useful as pasture land for their animals. The particular seeding mixtures commonly used to re-vegetate reclaimed mines is actually better for pasture than was the original pre-mine vegetative cover. Associated benefits will include food and cover for wildlife.

As reclamation projects in Indiana have progressed, the reclaimed area has been mostly covered. The pH is back into the acceptable range of parameters (pH of 6-9).  The Deer Ridge Mine, which has affected 1846.4 acres in Warrick and Pike counties, is undergoing a reclamation process supervised by the Department of Reclamation of Indiana Department of Natural Resources. Most of the affected area has been reclaimed to post mining land uses of wildlife/ forest/wetland. All pre-mining crop Xland acres have been returned to crop land. Prime farmland has had 4 feet or more of soil replaced. Non-prime crop has a minimum of 18 inches. Wildlife and forest land uses have a minimum of 12 inches. Most land uses have more than the minimum required. For example, soils to depths of 3 feet were added in some wildlife areas where 12 inches is all that is required by 310 IAC (the Indiana surface mine reclamation rules and regulations). Native Prairie grasses have been planted on a portion of the wildlife areas with some success. Big blue stem, and little blue stem, Indian grasses, and switch grass have also been planted.