Introduction
Agriculture has played a significant role in Mississippi’s history. During the early periods of its settlement, the inhabitants relied upon the abundant natural resources for food and shelter. Even in the modern era, agriculture remains the number one industry, with enormous employment opportunities for the citizenry in 82 counties of the state. In 1999, it was estimated that one in five employees in the state held a job related to agriculture [
1]. The sector employs 30 percent of the state’s workforce either directly or indirectly and generates over $5.6 billion in revenues annually. The state’s farmland stretches through an area covering 11 million acres [
2–
4].
Accordingly, the socio-economic trends and history of Central Mississippi reveal a major rural influence due to a dependence on agricultural activities as part of the economic engine driving the state’s economy [
5]. Yet, the amount of agricultural land in the counties continues to decline. Similar changes in a host of other variables associated with agricultural land use and the continuity of farming in the state have occurred. In 1959, Mississippi contained 18,600,000 acres of farmland [
6]. That number had declined to 10,600,000 by 2000. Similarly, the total number of farms in Mississippi has decreased by 11,000 since 1982. In 1982, 11 counties in the state had at least 751 farms each; by 1997, only two counties showed that many. Also in 1982, eight counties contained 275,000 acres or more, by 1997 only five counties did. The gravity of such losses in 80 of the 82 counties led to a total decrease of over 2 million acres from 1982 to 1997 [
7].
Central Mississippi and other regions in the state have also experienced rapid population growth and have expanded into rural areas to accommodate this growth. This urbanization of rural areas triggers changes that often alter the environmental amenities that urban dwellers were seeking when they migrated into the countryside. The scenic appeal and quality of natural resources in rural areas have been important factors in bringing population growth to the countryside. As urban growth expands into rural areas, the land base changes. One critical impact on the natural resource base is the conversion of agricultural land to urban uses. This change often engenders the reduction of aesthetic and ecological values of natural areas [
8]. The growing incidence of agricultural land loss partly attributable to urbanization also poses an enormous threat to preservation of agricultural land in the state [
9]. From 1992 to 1977, urbanized acreage rose by 196,900 acres. Much of this lost acreage came from pasture (37,500 acres) and soybean production (13,100 acres). Cropland under irrigation in 1992 and developed by 1997 totaled 4,500 acres, most of which produced cotton (2000 acres). Given the effects of these trends on the future capacity to produce food items, there are concerns that farmland loss may also erode the basis for sustainable use of agricultural land, biodiversity and the protection of the state’s ecological treasures [
10].
Notwithstanding the situation in Mississippi, the phenomenon of sprawling urban development stands as one of the key factors driving land use and land cover changes in the United States. The US Department of Agriculture’s Natural Resources Conservation Service estimates that over 12 million acres of land were converted to developed land in the United States during the period between 1982 and 1997. During that period, farmland accounted for over 50 percent of newly developed land, while another third came from forestland [
11]. This intensification in urban land development at the expense of open space and natural lands has sparked a growing debate over the problems and benefits of urban development and sprawl.
Given that the literature on urban development is so broadly dispersed, it is quite difficult to limit the definition and conceptual analysis to a single domain. As a result, several definitions for sprawl have been coined that describe sprawl as a specific form of urban development with low-density, dispersed, auto-dependent, and environmentally and socially-impacting characteristics [
12,
13]. The negative externalities emanating from urban sprawl have been widely documented [
14–
17]. Other scholars have identified benefits of sprawl-style development [
18,
19]. Of particular concern is the extent of land consumption and the inefficient nature of this type of growth and the increasing amount of critical land resources lost in relation to human population growth [
20–
23]. However, from the standpoint of research and management, there is still a great need to further our understanding of spatial and temporal patterns of urban land use.
To keep up with these changes, agencies from all levels of government and the private sector devote substantial resources to obtaining spatial information systems to study the impacts of urban infrastructure on agricultural land [
24]. Notwithstanding the gravity of the trends, no major research effort has aimed at documenting the incidence of agricultural land loss due to urban development in Central Mississippi through the use of GIS. The crucial question remains, what changes have taken place in the amount and distribution of agricultural land within individual counties and what factors are responsible for it? If patterns of land loss can be determined through this technique, then future urban land development and conversion could be better predicted and better judgments could be made in developing land use policies and strategies restricting land use [
25].
The Purpose and Organization of the Research
This project examines farmland loss in Central Mississippi from a temporal-spatial perspective with a focus at the county level, between 1987 and 2002. Alternate strategies for farmland protection, based upon growth management, land information inventory and mapping, as well as community participation in the region, are also recommended. This paper contains five sections. Section 1 offers a description of the methodology and the study area. Section 2 presents the results and data analysis, while section 3 discusses the findings and their significance to land management. The fourth section offers recommendations for change in land-use policy. The final section summarizes the importance of the study to the future of agricultural productivity in Mississippi and elsewhere. To analyze the trend, the project adopts a time series approach, descriptive statistics, regression analysis and Geographic Information System (GIS) mapping of socioeconomic and land data from the United States Census. This paper has three objectives. The prime objective is to update the existing literature. A second objective is to provide a useful tool for decision makers within the domain of natural resources management. The third objective is to show how the latest advances in GIS can be used to enhance land management at the county level.
Methods Used
This paper uses a mixed-scale approach based on government databases. The spatial information for the research was obtained from the Mississippi Automated Resource Information System office in Jackson, Mississippi, the American Farmland Trust and United States Census of Agriculture for 1987, 1992, 1997 and 2002. Federal geographic identifier codes for the seven counties (Copiah, Hinds, Rankin, Madison Simpson, Warren, and Yazoo) were used to geo-code the information contained in the data sets. The spatial data came from land-use capability and classification maps for the study area. This information was analyzed with basic descriptive statistics, regression analysis, and GIS, with particular attention to the temporal-spatial trends at the county level. The relevant procedures consisted of two stages, as described below.
Stage 1: Identification of Variables, Data Gathering and Study Design
The initial step in this research involves the identification of the variables required to analyze changes at the county level from 1987 to 2002. The variables consist of socioeconomic and environmental information, including amount of agricultural land, average size of farms, market value of land, value of machinery, amount of cropland, number of housing permits, population and selected indicators on housing (homeownership rate, income and unit structure)(See
Tables 1 through 4). Appropriate variables were derived from secondary sources such as government documents, newsletters and previous works. That process was followed by the design of data matrices for socioeconomic and land use (environmental) variables covering the census periods from 1987 to 2002. The design of spatial data for the GIS analysis required the delineation of city boundary lines within the study area as well. Given that the official boundary lines between the seven counties remained the same, a common geographic identifier code was assigned to each of the areal units to ensure analytical coherency.
Stage 2: Data Analysis
In the second stage, descriptive statistics and regression analysis were employed to transform the original socioeconomic and land-use data into relative measures (percentages, ratios and rates). This process generated the parameters for establishing, the extent of change or land loss for each of the seven counties facilitating gradual measurement and comparison of the trends in the area overtime. This approach allows detection of levels of change, while the graphics highlight the land-loss trends affecting the study area. The remaining steps involve spatial analysis and output (maps-tables-text) covering the study period, using ARCVIEW. The spatial units of analysis consisted of the seven counties (
Figure 1). The study area map indicates boundary limits of the county units and their geographic identification codes. Outputs for each county were mapped and compared across time. This process helped show the spatial evolution of farmland loss, as well as changes in other variables.
Discussions
The results indicate that the counties under consideration have experienced considerable changes in the size of agricultural land and host of other variables associated with the use of farmland due to urbanization. The nature and extent of this change transcend all spatial units, regardless of their designation as urban or rural. Another important point to note is Hinds’ County’s status as the county that contains the Metropolitan Statistical Area’s central city of Jackson. To a great extent, the growth in urbanized land in Rankin and Madison is related to this. In spite of some minor gains attributable to best management practices, agricultural land loss has become a major land management challenge for planners in the area [
39–
41]. The pattern of demographic change reveals that population growth and sprawl are threatening the preservation of agricultural land. Additionally, the rapid growth rates of the area coincide with a growing disturbance in the surrounding natural ecosystems. Growth pressure is also evident in the widespread request for building permits to meet domestic needs for new homes.
In light of these findings, it is evident that GIS stands as a valuable tool for decision makers and resource managers in gauging the problems posed by growth and development. Given the negligible effort to document the incidence of land loss due to linkages to urban development in Mississippi, this study not only fills that void, but also it fills an important gap in the literature. The temporal and spatial display of information pertaining to demographic and socioeconomic indicators of growth, and their potential impacts on land use, offers the decision makers the opportunity to craft response mechanisms to dealing with the problems created by urban development [
42]. GIS also offers county managers an appropriate tool for tracking the status of lands with high resource values and protecting them from development. Such information is essential in shaping the contours of Smart Growth policies and enabling local governments in Central Mississippi District to prepare plans for effective land uses.