Ecosystem Services: A 21st Century Policy Challenge

Resource /Energy Economics and Policy,

The Characterization Of The Effects Of Stress Concentrations On The Mechanical Behavior Of A Micronic Woven Wire Mesh

Woven structures are steadily emerging as excellent reinforcing components in dualphase composite materials subjected to multiaxial loads, thermal shock, and aggressive reactants in the environment. Metallic woven wire mesh materials display good ductility and relatively high specific strength and specific resilience. While use of this class of materials is rapidly expanding, significant gaps in mechanical behavior classification remain. This thesis works to address the mechanics of material knowledge gap that exists for characterizing the behavior of a metallic woven structure, composed of stainless steel wires on the order of 25 microns in diameter, and subjected to various loading conditions and stress risers. Uniaxial and biaxial tensile experiments, employing Digital Image Correlation (DIC) as a strain measurement tool, are conducted on woven wire mesh specimens incised in various material orientations, and with various notch geometries. Experimental results, supported by an ample analytic modeling effort, indicate that an orthotropic elastic constitutive model is reasonably capable of governing the macro-scale elasticity of the subject material. Also, the Stress Concentration Factor (SCF) associated with various notch geometries is documented experimentally and analytically, and it is shown that the degree of stress concentration is dependent on both notch and material orientation. The Finite Element Method (FEM) is employed on the macro-scale to expand the experimental test matrix, and to judge the effects of a homogenization assumption when modeling metallic woven structures. Additionally, plasticity of the stainless steel woven wire mesh is considered through experimental determination of the yield surface, and a thorough analytic modeling effort resulting in a modified form of the Hill yield criterion. Finally, mesoscale plasticity of the woven structure is considered, and the form of a multi-scale failure criterion is proposed and exercised numerically

Evaluation of policy tools to establish forests and protect water quality in cornbelt watersheds

The 1990 Farm Bill provides a number of incentives to farmers and farmland owners to improve water quality by retiring critical croplands through the Conservation Reserve Program (CRP) and the Agricultural Wetland Reserve Program (AWR), and by controlling chemical use through the Water Quality Incentives Program (WQIP). This study utilizes two contingent valuation methodologies on 770 mail surveys and 157 personal interviews in 10 Cornbelt counties to estimate potential participation in these programs as a function of financial incentives offered. It also identifies possible barriers to increased enrollment and presents farmers7 attitudes toward these programs as well as toward Swampbuster. The results show that potential enrollments in the WQIP are low; only 17.5% of respondents indicated an interest in participating. In contrast, potential enrollments of filter strips, recharge areas, and farmed wetlands in the CRP respond strongly to annual rental rates, particularly in the range $90-1401 acre. Enrollments in 30-year easements are lower, but also respond strongly to increased lump sum payments. In contrast, most respondents are clearly resentful of Swampbuster restrictions on wetland drainage.U.S. Department of the InteriorU.S. Geological SurveyOpe

ECOLOGICAL-ECONOMIC MODELING ON A WATERSHED BASIS: A CASE STUDY OF THE CACHE RIVER OF SOUTHERN ILLINOIS

A digitally represented watershed landscape (ARC/INFO GIS) is merged with farm optimization (linear programming) and sediment and chemical transport (AGNPS) models. Enhanced targeting of non-point source pollution to remedial policy and management initiatives result. The implications of which are linked back to farm income and forward to the managed ecosystem.Environmental Economics and Policy, Research and Development/Tech Change/Emerging Technologies,

THE TECHNICAL EFFICIENCY OF ILLINOIS GRAIN FARMS: AN APPLICATION OF A RAY-HOMOTHETIC PRODUCTION FUNCTION

The purpose of this paper is to measure the extent of technical inefficiency among a sample of Illinois grain farms using the corrected ordinary least squares method. Instead of assuming a Cobb-Douglas production function, a linear form of the ray-homothetic is used. The results show a significant amount of technical inefficiency among all the farms in the sample, but with large farms being less technically inefficient than small farms.Crop Production/Industries,

An Agent-Based Model of Multifunctional Agricultural Landscape Using Genetic Algorithms

Landowner characteristics influence his/her willingness to change landuse practices to provide more or less environmental benefits. However, most studies of agricultural/environmental polices identify landowners as homogenous. And, the primary cause of failure of many environmental and other polices is the lack of knowledge on how humans may respond to polices based on changes in their behavior (Stern, 1993). From socioeconomic theory and empirical research, landowners can be identified as individuals who make agricultural landuse decisions independently based on their objectives. Identifying possible classes of landowners, assessing how each would potentially respond to policy alternatives, and the resulting pattern of land uses in a watershed or a riparian corridor would be very useful to policy makers as they evaluated alternatives. Agricultural landscapes are important producers of ecosystem services. The mix of ecosystem services and commodity outputs of an agricultural landscape depends on the spatial pattern of land uses emerging from individual land use decisions. However, many empirical studies show that the production of ecosystem services from agricultural landscapes is declining. This is consistent with research conducted over the last few decades showing there is a narrow range of social circumstances under which landowners are willing to make investments in the present to achieve public benefits in the future through investing in natural capital resulting in public goods which are frequently produced as ecosystem services. In this study an agent-based model within a watershed planning context is used to analyze the tradeoffs involved in producing a number of ecosystem services and agricultural commodities given price and policy scenarios while assuming three different types of agents in terms of their goals. The agents represent landowners who have been divided into a number of different groups based on their goals and the size of their farm operations. The multi-agent-based model is developed using a heuristic search and optimization technique called genetic algorithm (GA) (Holland), which belongs to a broader class of evolutionary algorithms. GAs exhibit three properties (1) they start with a population of solution, (2) they explore the solution space through recombination and mutation and (3) they evaluate individual solutions based on their appropriate fitness value(s), for example given profit maximizing agents this would be gross margin. A GA is a heuristic stochastic search and optimization method, which works by mimicking the evolutionary principles and chromosomal processing in natural genetics. The three economic agents that are modeled are based on variations in their objective functions and constraints. This study will help in identifying the tradeoffs associated with various agents in the provision of ecosystem services and agricultural commodities. The agent model developed here will help policy and decision maker identify the various agents within the watershed and assess various policy options based on that information. The study will also help to understand the interaction and feedback between the agents and their environment associated with various policy initiatives. The results of the study indicate that the agent model correctly predicts the actual landuse landcover map by 75 percent.Multifunctional agriculture, Agent based modeling, Genetic Algorithm, Environmental Economics and Policy, Land Economics/Use,

COMPARATIVE STUDY OF SHOE-SURFACE INTERACTION IN TRAIL RUNNING - SUBJECTIVE AND OBJECTIVE EVALUATION

The purpose of this study is to compare and evaluate different running shoes in various surface conditions in two measurement phases. In the subjective test, fourteen trail runners performed the experiment with three running shoes in distinct surface conditions. Three features, comfort, cushioning and traction, were rated by means of questionnaire. In the objective measurement, a traction tester device was configured to simulate the movement and evaluate the rotational traction of the three shoes on different surfaces. The subjective test showed a significant difference with respect to comfort and cushioning. The objective measurement in dry conditions showed a significant decrease (P \u3c 0.05) in rotational traction on different surface types; rotational traction in wet conditions was significantly lower (P \u3c 0.05) than in dry conditions

REGIONAL ECONOMIC IMPACTS OF A WATERSHED PLANNING PROCESS TO REDUCE EROSION AND STREAM SEDIMENTATION

Farm-level and watershed-wide land-use changes resulting from policy initiatives are linked to a regional input/output model. As a result not only can the direct economic impacts at the farm and watershed levels be determined, so too can the direct and induced economic impacts at the regional level.Resource /Energy Economics and Policy,

Proposal for a Model State Watershed Management Act

During the Montana Constitutional Convention of 1889, John Wesley Powell, envisioning a landscape of watershed commonwealths, proposed that Montana adopt watersheds as the boundaries of its counties. The idea did not catch on. Over time, the power of local governments to regulate land use has grown immensely, but the misfit between their political boundaries and environmental policy problem sheds has persisted. As our understanding of ecosystem dynamics improves, however, natural resources management policy is gravitating, once again, to the watershed as an appropriate unit of governance. Many federal and state natural resource management initiatives have come on line in the past five years using watersheds as their primary focus. Yet, these new programs lack coherence and invest inadequate authority in watershed-based units of government. Representing perspectives from law, geography, economics, and anthropology, the authors propose the framework for a model state watershed management law. They conclude that the federal government is ill-equipped to take on the role of comprehensive watershed management czar as it has for pollution control and other environmental programs. Yet, local governments, even if organized around watershed boundaries, are unlikely to provide the platform for effective policy implementation. Rather, the authors propose a multi-tiered governance system linking state, regional, and local units of government through careful distribution of planning responsibilities and policy implementation authorities. Although for many states this framework would introduce a new layer of governance, its superior correspondence to the inescapable realities of ecosystem dynamics makes it worth serious consideration