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PROBLEM FORMULATION REPORT: FOR THE ASSESSMENT OF THE CONSEQUENCES OF GLOBAL CHANGE FOR AQUATIC ECOSYSTEMS
Citation:
Jarnagin, S T. PROBLEM FORMULATION REPORT: FOR THE ASSESSMENT OF THE CONSEQUENCES OF GLOBAL CHANGE FOR AQUATIC ECOSYSTEMS. EPA/600/S-02/004.
Impact/Purpose:
Overarching Objectives and Links to Multi-year Planning
This research directly supports long-term goals established in ORD's multi-year research plans related to GPRA Goal 2 (Water Quality) and Long Term Goal WQ-2 Assessment of aquatic systems impairment. Relative to the GRPA Goal 2 Water Quality multi-year plan, this research will "provide tools to assess and diagnose impairment in aquatic systems and the sources of associated stressors" and "provide the tools to restore and protect aquatic ecosystems and to forecast the ecological, economic, and human health outcomes of alternative solutions" (Water Quality Long Term Research Goals 2 and 3).
Subtask 1 - Impervious Surface Evaluation
This subtask addresses the development of impervious surfaces estimators for local to regional scale assessments of watersheds and their landscape relationship to stream ecology. The amount of impervious surface area in a watershed is a key indicator of landscape change. As a single variable, it serves to integrate a number of concurrent interactions that directly influence a watershed's hydrology, stream chemical quality, and in-stream habitat. It is our working hypothesis that impervious surface area within a watershed, as an independently mapped predictor variable, can be used to generally track a range of watershed ecological parameters (e.g., NPS pollution, biological integrity, TMDLs) that are of concern to local, state and federal environmental managers. The specific objectives of this research are: 1) to quantitatively evaluate the varying remote sensing methods used in mapping impervious surfaces at multiple scales (local to regional), and 2) to relate the varying levels of impervious surface area in watersheds to the environmental condition of multiple water resource endpoints such as streamflow, temperature, and biota.
Subtask 2 -- Landscape Assessments and Evaluations of Best Management Practices: Watershed Demonstrations
Best Management Practices (BMP) encompass a range of strategies to reduce water pollution related to urban and agricultural activities. EPA, through Section 319(h) of the Clean Water Act [PL 92-500], provides grants to states to implement BMPs in areas with suspected or known water-quality problems. Grants for implementation of BMPs have not been tracked or monitored to document their effectiveness. Although effectiveness can be measured in many different ways, one straightforward but important measure is existence. Implementation of BMPs is a voluntary process and actual implementation is not always executed (Nowak 1992). The primary objective of this project is to assess the feasibility of using high-resolution aerial photography and other remotely sensed data to identify the existence of BMPs that were planned under the 319 program. An additional objective is to evaluate the effectives of BMPs implemented by examining monitoring data from about 5 sites in the OW National NPS monitoring system.
There are several potential benefits to determining the feasibility of using the aerial photography for identifying BMPs: 1) since BMP implementation is voluntary and some may not be implemented due to a variety of social and economic factors (Nowak 1992), remote detection of BMPs can provide data to estimate the ratio of BMPs implemented to BMPs planned; 2) remote detection of BMPs provides validation data that can be input into EPA's Grants Reporting and Tracking System (GRTS), and 3) remote monitoring of BMPs over time could be used to develop data on BMP lifespans, providing important data related to social- and cost-effectiveness.
Subtask 3 -- TMDL Non-point Source Assessment Tool
This subtask involves the development of a software tool to assess the potential risks of water bodies to exceed TMDL threshold values established by States. When completed, the tool will allow the user to evaluate watersheds over entire regions. The too
Description:
Meyer (1995) describes land use as "the way in which, and the purposes for which, human beings employ the land and its resources; for example, farming, mining, or lumbering" and land cover as "the physical state of the land surface: as in cropland, mountains, or forests". The definition of the term land cover has broadened in recent usage to include human structures such as buildings or pavement (impervious surfaces) and other aspects of the natural environment, such as soil type, biodiversity, and surface and groundwater (Meyer, 1995). As human population and activities have increased over time, changes in land use and land cover change due to human activities have become major factors in changes in ecological processes at local to global scales (Groom and Schumaker, 1993; Houghton, 1994; Imhoff, 1994; Ojima et al., 1994). Human beings act as a keystone species: a species that regulates ecosystem structure and function (Ricklefs, 1993). Human activates alter not only their own environment but also act directly and indirectly to structure the ecosystem for all other organisms. Recently, human activities have increased to a level where they dominate the Earth's global ecosystem. Between one-third and one-half of the land surface of the planet Earth has been transformed by human activity (Vitousek et al., 1997) with approximately 40% of the Earth's terrestrial vegetated surface impaired in its ability to furnish benefits due to human activity (Daily, 1995). Humans appropriate more than 30% of terrestrial net primary production (Vitousek et aL, 1986; Rojstaczer et al., 2001) and human use accounts for 25% of the world's total evapotranspiration and 50% of the accessible runoff supply of fresh water (Postel et al., 1996). The consequences of land use and land cover change at a global scale are not easily measured and quantified but have impacts on global processes such as climate change (Houghton et al., 1999; Hurtt, et aL, 2002), resource depletion (Peskin, 1990; Daily, 1997), nutrient and hydrologic cycling (Nobre et al., 1991; Rasmussen et al., 1998), biodiversity (Wilson, 2002), and, ultimately, the carrying capacity of the Earth for human populations (Cohen, 1995a). At a regional scale, the impacts of agriculture, deforestation, and development on regional climate are greater than global changes in C02 (Couzin, 1999; Caspersen, et al., 2000; Schimel, et al., 2000). For terrestrial ecosystems, future global biodiversity is most dependent upon changes in human population and land use (Sala et al., 2000; Wilson, 2002).