Geology topics

William L. Graf

Publications and source records attributed to William L. Graf.

4 recordsLinked to original sources

USGS2015

Proposed best modeling practices for assessing the effects of ecosystem restoration on fish

Large-scale aquatic ecosystem restoration is increasing and is often controversial because of the economic costs involved, with the focus of the controversies gravitating to the modeling of fish responses. We present a scheme for best practices in selecting, implementing, interpreting, and reporting of fish modeling designed to assess the effects of restoration actions on fish populations and aquatic food webs. Previous best practice schemes that tended to be more general are summarized, and they form the foundation for our scheme that is specifically tailored for fish and restoration. We then present a 31-step scheme, with supporting text and narrative for each step, which goes from understanding how the results will be used through post-auditing to ensure the approach is used effectively in subsequent applications. We also describe 13 concepts that need to be considered in parallel to these best practice steps. Examples of these concepts include: life cycles and strategies; variability and uncertainty; nonequilibrium theory; biological, temporal, and spatial scaling; explicit versus implicit representation of processes; and model validation. These concepts are often not considered or not explicitly stated and casual treatment of them leads to mis-communication and mis-understandings, which in turn, often underlie the resulting controversies. We illustrate a subset of these steps, and their associated concepts, using the three case studies of Glen Canyon Dam on the Colorado River, the wetlands of coastal Louisiana, and the Everglades. Use of our proposed scheme will require investment of additional time and effort (and dollars) to be done effectively. We argue that such an investment is well worth it and will more than pay back in the long run in effective and efficient restoration actions and likely avoided controversies and legal proceedings.

Ecological Modelling↗

USGS2010

Reclaiming freshwater sustainability in the Cadillac Desert

Increasing human appropriation of freshwater resources presents a tangible limit to the sustainability of cities, agriculture, and ecosystems in the western United States. Marc Reisner tackles this theme in his 1986 classic Cadillac Desert: The American West and Its Disappearing Water . Reisner's analysis paints a portrait of region-wide hydrologic dysfunction in the western United States, suggesting that the storage capacity of reservoirs will be impaired by sediment infilling, croplands will be rendered infertile by salt, and water scarcity will pit growing desert cities against agribusiness in the face of dwindling water resources. Here we evaluate these claims using the best available data and scientific tools. Our analysis provides strong scientific support for many of Reisner's claims, except the notion that reservoir storage is imminently threatened by sediment. More broadly, we estimate that the equivalent of nearly 76% of streamflow in the Cadillac Desert region is currently appropriated by humans, and this figure could rise to nearly 86% under a doubling of the region's population. Thus, Reisner's incisive journalism led him to the same conclusions as those rendered by copious data, modern scientific tools, and the application of a more genuine scientific method. We close with a prospectus for reclaiming freshwater sustainability in the Cadillac Desert, including a suite of recommendations for reducing region-wide human appropriation of streamflow to a target level of 60%.

Proceedings of the National Academy of Sciences of↗

USGS2005

Geography for a Changing World - A science strategy for the geographic research of the U.S. Geological Survey, 2005-2015

This report presents a science strategy for the geographic research of the U.S. Geological Survey (USGS) for the years 2005-2015. The common thread running through the vision, mission, and science goals presented in the plan is that USGS geographers will provide national leadership to understand coupled human-environmental systems in the face of land change and will deliver pertinent information to decisionmakers on the vulnerability and resilience of these systems. We define land change science as the study of the human and environment dynamics that give rise to changed land use, cover, and surface form. A number of realities shape the strategic context of this plan: The Department of Interior Strategic Plan focuses on meeting society’s resource needs and sustaining the Nation’s life support systems, underscoring the importance of characterizing and understanding coupled human-environmental systems. In redefining its mission in the mid-1990s, the USGS envisions itself as an integrated natural science and information agency. The USGS will assume a national leadership role in the use of science to develop knowledge about the web of relations that couple biophysical and human systems and translate this knowledge into unbiased, reliable information that meets important societal information needs. The following trends will influence USGS geography-oriented science activities over the next decade. Most of the emerging earth science issues that the USGS will address are geographic phenomena. A growing international concern for aligning society’s development activities with environmental limits has led to an articulation of a science agenda associated with global environmental change, vulnerability, and resilience. Earth science investigations have evolved toward the study of very large areas, and the resulting huge volumes of data are challenging to manage and understand. Finally, scientists and the public face the challenge of gaining intelligent insights about geographic and environmental processes from these data, with the ultimate goal of guiding resource-management decisions. The first four science goals in the plan support understanding the human and environmental dynamics of land change. Each science goal has an associated set of strategic actions to achieve the goal. These goals and actions are consistent with national science priorities and the Department of Interior and USGS missions, take advantage of existing expertise, and lead to the strengthening of critical geographic research capacities that do not exist in other USGS disciplines.

Circular↗

USGS1987

Colorado Plateau

Field studies in the Colorado Plateau occupy an honored place in the development of geomorphic theory. The purpose of this chapter is to briefly review the foundational, regional, and process-oriented studies in the region, and to provide a review of promising threads of inquiry set in a context of more than a century of geomorphologic research in the region. The Colorado Plateau has sharply defined boundaries that separate it from neighboring geomorphic provinces (Fig. 1; for details see Thornbury, 1965). On the west, faults and the perimeters of volcanic plateaus mark the boundary between the Colorado Plateau and the Basin and Range Province. The boundary extends across the southern edge of the plateau where it is less radically defined, but is nonetheless visible on the surface in the form of an uplifted edge of sedimentary rocks known as the Mogollon Rim, which extends from northwest Arizona diagonally into north-central New Mexico. The eastern and northern boundaries are delineated by the contact between sedimentary rocks and upthrust or folded crystalline rocks of the Rocky Mountains. The plateau is a definable tectonic unit relatively easily separated from other provinces, but it shows considerable internal variation (Fig. 1; for details see Hunt, 1974a). The interior of the kidney-shaped Colorado Plateau Province reveals a series of subsections that depend on geologic and geomorphologic definition. The centrally located Canyon Lands Section is dominated by gently folded sedimentary rocks, while the western High Plateaus Section reveals widespread accumulations of volcanic materials.

Arizona, Colorado, New Mexico, Utah↗