Long-term dynamics in land resource use and the driving forces in the Beressa watershed, highlands of Ethiopia

Land degradation in the Ethiopian highlands is considered to be one of the major problems threatening agricultural development and food security in the country. However, knowledge about the forces driving the long-term dynamics in land resources use is limited. This research integrates biophysical information with socio-economic processes and policy changes to examine the dynamics of land resource use and farmers' livelihoods in the Beressa watershed for over 40 years during the second half of the 20th century. It was found that there have been substantial dynamics in land resource use in the area. The natural vegetation cover has been extensively cleared, although most of the cleared areas have since been replaced with plantations. Grazing land has expanded remarkably at the expense of cropland and bare land. However, the expansion of cropland was minimal over the 43-year period despite a quadrupling of the population density. Yields have not increased to compensate for the reduction in per capita cropland, and the soil quality appears to be not that good. Though the farmers perceived it otherwise, the long-term rainfall pattern has improved. In response to soil degradation, water shortage, socio-economic and policy changes, farmers have tended to gradually change from annual cropping to tree planting and livestock production to cope with the problems of soil degradation, water scarcity and smaller farms. Income diversification through the sale of wood and cattle dung is becoming a major livelihood strategy. Apparently, however, little attention has been paid to investments in soil and water conservation (SWC) and local soil fertility amendments. In particular, increased erosion and related high nutrient losses in sediments, as well as the removal of potentially available soil nutrients through the sale of manure threatens to damage agricultural sustainability in the area.     

Assessing Land-Use Impacts on Natural Resources

/ Much information is available on changes that occur in natural resources from both spatially-explicit data on environmental conditions and models of the interactions of these conditions and resources with human activities. The strategy for assessing land-use impacts on natural resources developed in this paper provides a framework for using relevant data and models to address questions of how management practices can promote both use and protection of resources. This assessment strategy integrates spatially explicit environmental data using geographic information systems (GIS) with computer models that simulate changes in land cover in response to land-use impacts. The computer models also simulate susceptibility of species to changes in habitat suitability and landscape patterns. The approach is applied to management of limestone barrens on the Oak Ridge Reservation in East Tennessee. Potential limestone barrens habitats are identified by overlaying appropriate soils, geology, slope, and land-use/land-cover conditions. Their validity is tested against known sites containing rare species that occur in these habitats. The location of habitats at risk in the aftermath of human activities is determined by using an available area model that identifies the size and proximity of sites that particular types of species can no longer use as habitat. The resulting risk map can be used in land management planning. The approach uses readily available in situ and remotely sensed data and is applicable to a wide range of locations and land-use scenarios. This approach can be refined based on needs identified by land managers and on the sensitivity of the results to the resolution of available resource information.KEY WORDS: Land management; Assessment; Habitat characterization; Limestone barrens; Ecological modeling; Geographic information systems     

The Impact of Map and Data Resolution on the Determination of the Agricultural Utilisation of Organic Soils in Germany

Due to its nature, agricultural land use depends on local site characteristics such as production potential, costs and external effects. To assess the relevance of the modifying areal unit problem (MAUP), we investigated as to how a change in the data resolution regarding both soil and land use data influences the results obtained for different land use indicators. For the assessment we use the example of the greenhouse gas (GHG) emissions from agriculturally used organic soils (mainly fens and bogs). Although less than 5 % of the German agricultural area in use is located on organic soils, the drainage of these areas to enable their agricultural utilization causes roughly 37 % of the GHG emissions of the German agricultural sector. The abandonment of the cultivation and rewetting of organic soils would be an effective policy to reduce national GHG emissions. To assess the abatement costs, it is essential to know which commodities, and at what quantities, are actually produced on this land. Furthermore, in order to limit windfall profits, information on the differences of the profitability among farms are needed. However, high-resolution data regarding land use and soil characteristics are often not available, and their generation is costly or the access is strictly limited because of legal constraints. Therefore, in this paper, we analyse how indicators for land use on organic soils respond to changes in the spatial aggregation of the data. In Germany, organic soils are predominantly used for forage cropping. Marked differences between the various regions of Germany are apparent with respect to the dynamics and the intensity of land use. Data resolution mainly impairs the derived extent of agriculturally used peatland and the observed intensity gradient, while its impact on the average value for the investigated set of land-use indicators is generally minor.     

Managing Radioactively Contaminated Land: Implications for Habitat Diversity

Radioactive contamination of agricultural land may necessitate long-term changes in food production systems, through application of selected countermeasures, in order to reduce the accumulation of radionuclides in food. We quantified the impact of selected countermeasures on habitat diversity, using the hypothetical case of two agricultural areas in Finland. The management scenarios studied were conversions from grassland to cereal production and from grassland and crop production to afforestation. The two study sites differed with respect to present agricultural production: one being predominantly cereal production and seminatural grasslands, while the other was dominated by intensive grass and dairy production. Some of the management scenarios are expected to affect landscape structures and habitat diversity. These potential changes were assessed using a spatial pattern analysis program in connection with geographic information systems. The studied landscape changes resulted in a more monotonous landscape structure compared to the present management, by increasing the mean habitat patch size, reducing the total habitat edge length and reducing the overall habitat diversity calculated by the Shannon diversity index. The degree of change was dependent on the present agricultural management practice in the case study sites. Where dairy production was predominant, the landscape structure changes were mostly due to conversion of intensive pastures and grasslands to cereal production. In the area dominated by cereal production and seminatural grasslands, the greatest predicted impacts resulted from afforestation of meadows and pastures. The studied management changes are predicted to reduce biodiversity at the species level as well as diminishing species-rich habitats. This study has predicted prominent side effects in habitat diversity resulting from application of management scenarios. These potential long-term impacts should be considered by decision-makers when planning future strategies in the event of radionuclide deposition.     

Deforestation and Forest Management in Southern Ethiopia: Investigations in the Chencha and Arbaminch Areas

Long-term human impacts are considered to be the prime cause of unsustainable forest exploitation in Ethiopia. Yet there exist well-established systems and a wealth of local experience in maintaining and managing forests. This study explores the trends and driving forces of deforestation plus traditional practices regarding sustainable forest use and management in the Chencha and Arbaminch areas, Southern Ethiopia. Satellite image analysis (images from 1972, 1984 and 2006) combined with field surveys were used to detect and map changes in forest cover. Household interviews and group discussions with experienced and knowledgeable persons were also employed. The results show a 23 % decline in forest cover between 1972 and 2006 with the most significant change from 1986 to 2006. Change was greatest in the lowlands and remarkable episodic forest changes also occurred, suggesting nonlinear spatial and temporal forest cover dynamics. According to farmers, the main driver of deforestation is agricultural land expansion in response to local population increases and a decline in agricultural production. Growing local and regional fuel wood demand is another chief cause. Despite these issues, remarkable relicts of natural forests remain and trees on farmland, around homesteads and on fields in every village are basic elements of farm activities and social systems. This demonstrates the effect of cumulative traditional knowledge and long-term local experience with forest management and preservation. Therefore, these practices should be promoted and advanced through the integration of local knowledge and forest management practices in the design and implementation of sustainable environmental planning and management.     

Land-Cover Change Trajectories in Northern Ghana

Land-cover change trajectories are an emergent property of complex human–environment systems such as the land-use system. An understanding of the factors responsible for land change trajectories is fundamental for land-use planning and the development of land-related policies. The aims of this study were to characterize and identify the spatial determinants of agricultural land-cover change trajectories in northern Ghana. Land-cover change trajectories were defined using land-cover maps prepared from Landsat Thematic Mapper dataset acquired in 1984, 1992, and 1999. Binary logistic regression was used to model the probability of observing the trajectories as a function of spatially explicit biophysical and socioeconomic independent variables. Population densities generally increased along the continuum of land-use intensity, whereas distance from market and roads generally decreased along this continuum. Apparently, roads and market serve as incentives for settlement and agricultural land use. An increase in population density is an important spatial determinant only for trajectories where the dominant change process is agricultural extensification. A major response to population growth is an increase in cultivation frequency around the main market. Agricultural intensification is highly sensitive to accessibility by roads. The increase in land-use intensity is also associated with low soil quality. These results suggest the need for policies to restore soil fertility for agricultural sustainability. The models also provide a means for identifying functional relationships for in-depth analyses of land-use change in Ghana.     

Assessing Watershed-Scale, Long-Term Hydrologic Impacts of Land-Use Change Using a GIS-NPS Model

Land-use change, dominated by an increase in urban/impervious areas, has a significant impact on water resources. This includes impacts on nonpoint source (NPS) pollution, which is the leading cause of degraded water quality in the United States. Traditional hydrologic models focus on estimating peak discharges and NPS pollution from high-magnitude, episodic storms and successfully address short-term, local-scale surface water management issues. However, runoff from small, low-frequency storms dominates long-term hydrologic impacts, and existing hydrologic models are usually of limited use in assessing the long-term impacts of land-use change. A long-term hydrologic impact assessment (L-THIA) model has been developed using the curve number (CN) method. Long-term climatic records are used in combination with soils and land-use information to calculate average annual runoff and NPS pollution at a watershed scale. The model is linked to a geographic information system (GIS) for convenient generation and management of model input and output data, and advanced visualization of model results. The L-THIA/NPS GIS model was applied to the Little Eagle Creek (LEC) watershed near Indianapolis, Indiana, USA. Historical land-use scenarios for 1973, 1984, and 1991 were analyzed to track land-use change in the watershed and to assess impacts on annual average runoff and NPS pollution from the watershed and its five subbasins. For the entire watershed between 1973 and 1991, an 18% increase in urban or impervious areas resulted in an estimated 80% increase in annual average runoff volume and estimated increases of more than 50% in annual average loads for lead, copper, and zinc. Estimated nutrient (nitrogen and phosphorus) loads decreased by 15% mainly because of loss of agricultural areas. The L-THIA/NPS GIS model is a powerful tool for identifying environmentally sensitive areas in terms of NPS pollution potential and for evaluating alternative land use scenarios for NPS pollution management.     

Modeling Change-Pattern-Value Dynamics on Land Use: An Integrated GIS and Artificial Neural Networks Approach

The use of spatial methods to detect and characterize changes in land use has been attracting increasing attention from researchers. The objectives of this article were to formulate the dynamics of land use on the temporal and spatial dimensions from the perspectives of the Change-Pattern-Value (CPV) and driving mechanism, based on multitemporal remote sensing data and socioeconomic data. The Artificial Neural Networks were used to identify the factors driving changes in land use. The Pearl River Delta Region of southeast China, which was experiencing rapid economic growth and widespread land conversion, has been selected as the study region. The results show that from 1985 to 2000 in the study region (1) the most prominent characteristics of change in land use were the expansion of the urban land at the expense of farmland, forests, and grasslands, (2) the land-use pattern was being optimized during this period, (3) in an analysis of value, built-up land can yield a return of more than 30 times that of farmland, water area, and forests lands, and (4) rapid economic development, growth in population, and the development of an infrastructure were major driving factors behind ecological land loss and the nonecological land expansion.     

Quantifying Terrestrial Ecosystem Carbon Dynamics in the Jinsha Watershed, Upper Yangtze, China from 1975 to 2000

Quantifying the spatial and temporal dynamics of carbon stocks in terrestrial ecosystems and carbon fluxes between the terrestrial biosphere and the atmosphere is critical to our understanding of regional patterns of carbon budgets. Here we use the General Ensemble biogeochemical Modeling System to simulate the terrestrial ecosystem carbon dynamics in the Jinsha watershed of China’s upper Yangtze basin from 1975 to 2000, based on unique combinations of spatial and temporal dynamics of major driving forces, such as climate, soil properties, nitrogen deposition, and land use and land cover changes. Our analysis demonstrates that the Jinsha watershed ecosystems acted as a carbon sink during the period of 1975–2000, with an average rate of 0.36 Mg/ha/yr, primarily resulting from regional climate variation and local land use and land cover change. Vegetation biomass accumulation accounted for 90.6% of the sink, while soil organic carbon loss before 1992 led to a lower net gain of carbon in the watershed, and after that soils became a small sink. Ecosystem carbon sink/source patterns showed a high degree of spatial heterogeneity. Carbon sinks were associated with forest areas without disturbances, whereas carbon sources were primarily caused by stand-replacing disturbances. It is critical to adequately represent the detailed fast-changing dynamics of land use activities in regional biogeochemical models to determine the spatial and temporal evolution of regional carbon sink/source patterns.     

DEVELOPMENT AND MANAGEMENT OF LAND/WATER RESOURCES: THE EVERGLADES,AGRICULTURE, AND SOUTH FLORIDA1

ABSTRACT: South Florida and the Everglades have been under intensive development since 1850 by Federal and State governments who encouraged and financed extensive drainage and hydraulic changes, primarily for agricultural settlement. Agricultural development of the sugar industry in the northern Everglades adjacent to Lake Okeechobee rapidly progressed only after the 1900s. Political and resource management conflicts have arisen because policies which once favored development are now being reversed by policies and regulation efforts to restore and conserve natural ecosystems. Currently, the environmental and ecological impacts of agricultural land use adjacent to natural wtlands of the Everglades are being assessed. The objectives of this paper are: (1) to outline the historical development of south Florida and the sugar industry, (2) to relate this history to political and management policy changes occurring as it pertains to ecosystem restoration and the multiuser competition for water/land resources, and (3) to propose how integrated resource management might be utilized for a sustainable Everglades and south Florida. This paper outlines the historical paradox of urban settlement, land development, and agricultural production, with efforts in the recent decade to acquire, manage, and preserve land and water resources for natural areas conservation. Only though the use of integrated resource management will the defined resource conflicts be mediated.     

Spatial and temporal dynamics of hedgerows in three agricultural landscapes of southern Quebec,Canada

Noncrop areas such as hedgerows in agricultural landscapes can perform several ecological and agronomic functions (e.g., habitat, movement corridors, windbreak, etc.), but their dynamics and drivers of changes are often poorly known. We conducted a study in three agricultural landscapes of southern Quebec, Canada, to assess and compare the spatial and temporal (1958–1997) dynamics of three hedgerow networks in relation to geomorphic conditions (marine, glacial, and mixed deposit) and land-use changes. Hedgerow networks were mapped and described in terms of their structure (density, degree of connectivity, and presence of trees or shrubs) and their relationship to other components of the landscape (connection to woodland). Relationships were assessed in time and space using nonparametric correlation, Mantel test, and principal components analysis (PCA). Results show significant differences between hedgerow structure for the three landscapes and distinct temporal and spatial dynamics that can be related to changes in management practices and agricultural policies. On marine deposits, increases in hedgerow density did not always correspond to an increase in their degree of connectivity, suggesting a possible reduction in network quality. On glacial deposits, hedgerow density declined following abandonment of agricultural land, but rather than disappearing, these linear structures were integrated into adjacent brush or forested areas. Our analysis reveals the complex spatial and temporal dynamics of the hedgerow networks and highlights the need to take into account spatial attributes such as connectivity and connection to woodland to evaluate more accurately overall network quality.     

Effects of climate and land use changes on groundwater resources in coastal aquifers

To estimate the freshwater loss in coastal aquifers due to salinisation, a numerical model based on the sharp interface assumption has been introduced. The developed methodology will be useful in areas where limited hydrological data are available. This model will elaborate on the changes in fresh groundwater loss with respect to climate change, land use pattern and hydrologic soil condition. The aridity index has been introduced to represent the variations in precipitation and temperature. The interesting finding is that the deforestation leads to increase groundwater recharge in arid areas, because deforestation leads to reduce evapotranspiration even though it favors runoff. The combined climate and land use scenarios show that when the aridity index is less than 60, the agricultural lands give higher groundwater recharge than other land use patterns for all hydrologic soil conditions. The calculated recharge was then used to estimate the freshwater-saltwater interface and percentage of freshwater loss due to salinity intrusion. We found that in arid areas, the fresh groundwater loss increases as the percentage of forest cover increases. The combined effects of deforestation and aridity index on fresh groundwater loss show that deforestation causes an increase in the recharge and existing fresh groundwater resource in areas having low precipitation and high temperature (arid climates).     

The Control of Land-Use Patterns for Stormwater Management at Multiple Spatial Scales

While most research about the relationship between land use and watershed hydrological output has focused primarily on land-use types and their impact on hydrological processes, the relationship between characteristics of land-use patterns (such as pattern fragmentation, connectivity, and coherence) and hydrological processes has not been well examined. Using historical stormwater data, this study evaluates the hydrological effects of different land-use scenarios in the Qing-shui watershed in Beijing, China, at a variety of spatial scales. This study demonstrates that planning and managing land-use patterns can significantly reduce runoff under different scales, particularly for small storm events. In contrast to other aspects of land-use structure characteristics, such as the shape complexity of land-use patches, fragmented level of the patches of land-use types appear as dominant drivers of runoff. The results of the study suggest that land-use pattern management should be an important component of Best Management Practices to reduce the impacts of urbanization on natural hydrological processes.     

An integrated approach to modeling resource utilization for rural communities in developing countries

Resource consumption in developing countries has been the focus of a considerable amount of research. What has been understudied however, has been the feedback affects of resource consumption on resource availability to both households and communities. Heavy reliance on natural resources and intensive smallholder agriculture common to many rural communities in developing countries has forced people to fulfill short-term needs to the detriment of long-term ecological and livelihood sustainability. This paper introduces a conceptual framework to examine how individuals and households fulfill daily caloric needs and the aggregate effects on resource availability and consumption. Data were collected from a large number of published case studies of rural land-use dynamics, growth and yield models, and human livelihoods were reviewed from scientific journals, reports published by NGOs, and government reports. Using inputs defined by the user, the model tracks annual fuelwood and agricultural land use based on meeting individual energy demands. A case-study-based analysis was patterned after smallholder agriculturalists at the family and community level. Three scenarios are presented in this paper using data from Uganda to illustrate the application of this model.     

Integrated resource assessment and sustainable land use

Decision makers and planners in resource sectors recognize, at least in theory, the multiple uses of land, reflecting possible choices and options for society, and the need to evaluate the economic, social, and environmental implications of these choices. As such, the need for integrated resource management is now widely accepted in resource planning. This article contributes to the understanding of sustainable resource development through a specific case study. An integrated analytical system is developed and applied to the Peace River Region, British Columbia, Canada, to examine the impacts of a wide range of land-use options and policies upon the achievement of multiple resource use goals. The results indicate that an integrated approach in land resource analysis is not only possible but a necessary step in the move to develop procedures for assisting public decision makers in integrating the diverse functions of the land resource base and to revise demands or develop alternative strategies in order to move society closer to sustainable outcomes.     

Land-use dynamics in a southern Illinois (USA) watershed

The Cache River of southernmost Illinois is used as a case study for developing and demonstrating an approach to quantitatively link (1) national agricultural policy and global agricultural markets, (2) landowner's decisions on land use, (3) spatial patterns of land use at a watershed scale, and (4) hydrologic impacts, thus providing a basis to predict, under a certain set of circumstances, the environmental consequences of economic and political decisions made at larger spatial scales. The heart of the analysis is an estimation, using logistic regression, of the affect of crop prices and Conservation Reserve Program (CRP) rental rates on farmland owner's decisions whether to reenroll in the CRP or return to crop production. This analysis shows that reasonable ranges for crop prices (80%–150% of 1985–1995 values) and CRP rental rates (0–125% of 1985–1995 rates) result in a range of 3%–92% of CRP lands being returned to crop production, with crop prices having a slightly greater effect than CRP rental rates. Four crop price/CRP rental rate scenarios are used to display resulting land-use patterns, and their effect on sediment loads, a critical environmental quality parameter in this case, using the agricultural non point source (AGNPS) model. These scenarios demonstrate the importance of spatial pattern of land uses on hydrological and ecological processes within watersheds. The approach developed can be adapted for use by local governments and watershed associations whose goals are to improve watershed resources and environmental quality.     

Conservation strategies for effective land management of protected areas using an erosion prediction information system (EPIS)

This research demonstrates the predictive modeling capabilities of a geographic information system (GIS)-based soil erosion potential model to assess the effects of implementing land use change within a tropical watershed. The Revised Universal Soil Loss Equation (RUSLE) was integrated with a GIS to produce an Erosion Prediction Information System (EPIS) and modified to reflect conditions found in the mountainous tropics. Research was conducted in the Zenzontia subcatchment of the Río Ayuquíla, located within the Sierra de Manantlán Biosphere Reserve (SMBR), México. Expanding agricultural activities within this area will accentuate the already high rate of soil erosion and resultant sediment loading occurring in the Río Ayuquíla. Two land-use change scenarios are modeled with the EPIS: (1) implementation of soil conservation practices in erosion prone locations; and (2) selection of sites for agricultural expansion which minimize potential soil loss. Confronted with limited financial resources and the necessity for expedient action, managers of the SMBR can draw upon the predictive capacity of the EPIS to facilitate rapid and informed land-use planning decisions.     

SIMULATING HYDROLOGIC AND WATER QUALITY IMPACTS IN AN URBANIZING WATERSHED1

ABSTRACT: The Hydrologic Simulation Program‐Fortran (HSPF) was calibrated and used to assess the future effects of various land development scenarios on water quality in the Polecat Creek watershed in Caroline County, Virginia. Model parameters related to hydrology and water quality were calibrated and validated using observed stream flow and water quality data collected at the watershed outlet and the outlets of two sub water sheds. Using the county's Comprehensive Plan, land use scenarios were developed by taking into account the trends and spatial distributions of future development. The simulation results for the various land use scenarios indicate that runoff volume and peak rate increased as urban areas increased. Urbanization also increased sediment loads mainly due to increases in channel erosion. Constituent loads of total Kjeldal nitrogen, orthophosphorus, and total phosphorous for Polecat Creek watershed slightly decreased under future development scenarios. These reductions are due to increases in urban areas that typically contribute smaller quantities of nitrogen and phosphorous, as compared to agricultural areas. However, nitrate loads increased for the future land use scenarios, as compared to the existing land use. The increases in nitrate loads may result from increases in residential land and associated fertilizer use and concurrent decreases in forested land. The procedures used in this paper could assist local, state, and regional policy makers in developing land management strategies that minimize environmental impacts while allowing for future development.     

Prospective changes in irrigation water requirements caused by agricultural expansion and climate changes in the eastern arc mountains of Kenya

Water resources and land use are closely linked with each other and with regional climate, assembling a very complex system. The understanding of the interconnecting relations involved in this system is an essential step for elaborating public policies that can effectively lead to the sustainable use of water resources. In this study, an integrated modelling framework was assembled in order to investigate potential impacts of agricultural expansion and climate changes on Irrigation Water Requirements (IWR) in the Taita Hills, Kenya. The framework comprised a land use change simulation model, a reference evapotranspiration model and synthetic precipitation datasets generated through a Monte Carlo simulation. In order to generate plausible climate change scenarios, outputs from General Climate Models were used as reference to perturbing the Monte Carlo simulations. The results indicate that throughout the next 20 years the low availability of arable lands in the hills will drive agricultural expansion to areas with higher IWR in the foothills. If current trends persist, agricultural areas will occupy roughly 60% of the study area by 2030. This expansion will increase by approximately 40% the annual water volume necessary for irrigation. Climate change may slightly decrease crops' IWR in April and November by 2030, while in May a small increase will likely be observed. The integrated assessment of these environmental changes allowed a clear identification of priority regions for land use allocation policies and water resources management.     

Use of agricultural land evaluation and site assessment in Linn County,Oregon, USA

Oregon state law requires each county in the state to identify agricultural land and enact policies and regulations to protect agricultural land use. State guidelines encourage the preservation of large parcels of agricultural land and discourage partitioning of agricultural land and construction of nonfarm dwellings in agricultural areas. A land evaluation and site assessment (LESA) system was developed in Linn County to aid in the identification of agricultural land and provide assistance to decision makers concerning the relative merits of requests to partition existing parcels of ricultural land and introduce nonagricultural uses.Land evaluation was determined by calculating soil potential ratings for each agricultural soil in the county based on the soil potentials for winter wheat, annual ryegrass, permanent pasture, and irrigated sweet corn. Soil potential ratings were expressed on a scale of 0 to 150 points. The land evaluation score for a parcel consists of the weighted average soil potential rating for all of the soils in the parcel, weighted by the percentage of each soil present in the parcel.Site assessment was based on the size of a parcel and on the amount of existing conflict between agricultural and nonagricultural uses, particularly rural residential uses, both adjacent to and in the vicinity of a parcel. Parcel size refers to both size in relation to a typical field and size in relation to a typical farm unit. Conflict takes into account the number of nonfarm dwellings within 1/4 mile (0.4 km) of a parcel, the amount of the perimeter that adjoins conflicting land uses, and the residential density adjacent to the parcel. Empirical scales were derived for assigning points to each of the site assessment factors. Both parcel size and conflict were worth 75 points in the model. For parcel size, 45 points were allocated to field size and 30 points to farm-unit size. For conflict, 30 points were allocated to nonfarm dwellings within 1/4 mile and 45 points to perimeter conflicts.The LESA model was validated by testing on 23 parcels in Linn County for which requests to partition and/or convert to nonagricultural uses had been received by the County Planning Department. This testing was an essential part of the development process, as it pointed out inconsistencies and errors in the model and allowed continuous adjustment of factors and point scales. The results of application of the final model to three of the case studies are presented to illustrate the concepts.Three possible uses of the information generated by the LESA system include determining the relative agricultural value of a parcel, determining grades of agricultural land suitability, and determining the impacts of changing land use on other parcels in the vicinity. Relative agricultural value is a direct outcome of application of the evaluation criteria in the LESA model. Good, marginal, and nonagricultural grades of agricultural suitability were determined by examining the data from all 23 test cases and establishing threshold point values for soil quality, conflict, parcel size, and total LESA score. Impact analyses were not done in this study, but could be achieved by calculating LESA scores for all parcels possibly affected by a land-use change both before and after a proposed change. All three applications fall short of making a specific land-use decision, but they do provide information that should be of value to the local jurisdiction charged with making such decisions.