The term flashiness reflects the frequency and rapidity of short term changes in streamflow, especially during runoff events. Flashiness is an important component of a stream's hydrologic regime. A variety of land use and land management changes may lead to increased or decreased flashiness, often to the detriment of aquatic life. This paper presents a newly developed flashiness index, which is based on mean daily flows. The index is calculated by dividing the pathlength of flow oscillations for a time interval (i.e., the sum of the absolute values of day‐to‐day changes in mean daily flow) by total discharge during that time interval. This index has low interannual variability, relative to most flow regime indicators, and thus greater power to detect trends. Index values were calculated for 515 Midwestern streams for the 27‐year period from 1975 through 2001. Statistically significant increases were present in 22 percent of the streams, primarily in the eastern portion of the study area, while decreases were present in 9 percent, primarily in the western portion. Index values tend to decrease with increasing watershed area and with increasing unit area ground water inputs. Area compensated index values often shift at ecoregion boundaries. Potential index applications include evaluation of programs to restore more natural flow regimes.
Existing models of agricultural decisionmaking based on economic optimization often fall short of capturing the complex dynamics of land-use choices at both individual parcel and watershed-level scales. The complexity arises from an interplay of several factors, as explained by Herbert Simon's model of bounded rationality, the theory of diffusion of innovations through spatial contagion, the role of personal environmental values and local culture, and simple historical momentum. This complexity can be captured using ‘artificial life agents’ that model land-use choice for individual parcels by considering characteristics and personal beliefs of the owner or operator, physical traits of the land, and information obtained via social networks. Agents are therefore able to consider holistically a large number of factors affecting land-use choice. The creation of agent-based models of human behavior described herein is based upon empirical data on the acceptance of Conservation Reserve Program for the Cache River watershed of southern Illinois (USA). These models are interfaced with a geographic information system to produce a spatial decision support system capable of anticipating the effects of policies that affect land-use decisionmaking on a real landscape and their economic performance.
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.
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
Local watershed planning is an increasingly important component of environmental management. This article provides an overview of local watershed management efforts occurring across the U.S. and then focuses on one case study from southern Illinois. First, analysis of 1145 local watershed groups shows that government agencies, farmers, and rural residents are key stakeholders in local groups that primarily deal with regional environmental stressors in the form of soil erosion, nutrients, and agrichemicals. Second, the role of watershed partnerships in mediating the complex interactions among stakeholders and local water resources are investigated through a case study of one watershed group. The Cache River is located in the far-southern tip of Illinois and a watershed planning process was initiated there in the 1990s. An in-depth assessment of this watershed planning process was accomplished through participant interviews, stakeholder focus groups, and a regional telephone survey. This case study illuminates how different stakeholder groups have varying perceptions as to the efficacy and success of watershed management plans.
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