David A. Mouat

Remote sensing techniques in the analysis of change detection

Abstract A review of remote sensing techniques in change detection studies is presented. Due to the nature of imagery examined, most change detection studies have involved the use of Advanced Very High Resolution Radiometer (AVHRR), Landsat Thematic Mapper (TM) and Multispectral Scanner (MSS), SPOT data, and aerial photography. Change detection techniques have included transparency compositing, image differencing, classification, band ratioing, and principal components analysis. This paper will focus on a review of the utility of these methods for various resource applications.

SCENARIO ANALYSIS FOR THE SAN PEDRO RIVER, ANALYZING HYDROLOGICAL CONSEQUENCES OF A FUTURE ENVIRONMENT

Studies of future management and policy options based on different assumptions provide a mechanism to examine possible outcomes and especially their likely benefits and consequences. The San Pedro River in Arizona and Sonora, Mexico is an area that has undergone rapid changes in land use and cover, and subsequently is facing keen environmental crises related to water resources. It is the location of a number of studies that have dealt with change analysis, watershed condition, and most recently, alternative futures analysis. The previous work has dealt primarily with resources of habitat, visual quality, and groundwater related to urban development patterns and preferences. In the present study, previously defined future scenarios, in the form of land-use/land-cover grids, were examined relative to their impact on surface-water conditions (e.g., surface runoff and sediment yield). These hydrological outputs were estimated for the baseline year of 2000 and predicted twenty years in the future as a demonstration of how new geographic information system-based hydrologic modeling tools can be used to evaluate the spatial impacts of urban growth patterns on surface-water hydrology.

DESERTIFICATION EVALUATED USING AN INTEGRATED ENVIRONMENTAL ASSESSMENT MODEL

Desertification has been defined as land degradation in arid, semi-arid and dry sub-humid areas resulting from various factors, including climatic variations and human activities (United Nations, 1992). A technique for identifying and assessing areas at risk fordesertification in the arid, semi-arid, and subhumid regionsof the United States was developed by the Desert Research Institute and the U.S. Environmental Protection Agency (EPA), using selected environmental indicators integrated into a Geographic Information System (GIS). Five indicators were selected: potential erosion, grazing pressure, climatic stress (expressed as a function of changesin the Palmer Drought Severity Index [PDSI]), change invegetation greenness (derived from the Normalized DifferenceVegetation Index [NDVI]), and weedy invasives as a percentof total plant cover. The data were integrated over aregional geographic setting using a GIS, which facilitateddata display, development and exploration of data relationships, including manipulation and simulation testing. By combining all five data layers, landscapes having a varying risk for land degradation were identified, providing a tool which could be used to improve landmanagement efficiency.

A process for selecting indicators for monitoring conditions of rangeland health

This paper reports on a process for selecting a suite of indicators that, in combination, can be useful in assessing the ecological conditions of rangelands. Conceptual models that depict the structural and functional properties of ecological processes were used to show the linkages between ecological components and their importance in assessing the status and trends of ecological resources on a regional scale. Selection criteria were developed so that relationships could be assessed at different spatial scales using ground and aerial measurements. Parameters including responsiveness and sensitivity to change, quality assurance and control, temporal and spatial variability, cost-effectiveness and statistical design played an important role in determining how indicators were selected. A total of ten indicator categories were selected by a committee of scientists for evaluation in the program. A subset that included soil properties, vegetation composition and abundance, and spectral properties was selected for evaluation in a pilot test conducted in 1992 in the Colorado Plateau region of the southwestern United States. This work is part of a major effort being undertaken by the U.S. Environmental Protection Agency and its collaborators to assess the condition of rangelands (primarily comprised of arid, semi-arid and dry subhumid ecosystems) along with seven other ecosystem groups (forests, agricultural lands, wetlands, surface waters, landscapes, estuaries and Great Lakes) as part of a national Environmental Monitoring and Assessment Program (EMAP). The indicator selection process reported upon was developed to support EMAPs goal of providing long-term, policy-relevant research focusing on evaluating the ecological condition (or health) of regional and national resources.

Desertification in the Mediterranean Region. A security issue

Proceedings of the NATO Mediterranean Dialogue Workshop on Desertification in the Mediterranean Region. A Security Issue Valencia, Spain 2-5 December 2003

Ecological Indicator Strategy for Monitoring Arid Ecosystems

Environmental issues such as global change, acidic deposition, and toxic wastes will continue to be of great economic, political, and social concern during the coming decades. Ecological pressures on the earth’s limited natural resources will increase as human activities continue to alter the earth’s ecosystems. Part of the problem in the past has been the tradition of dealing independently with environmental issues related to land, air, and water resources. Because these components of the environment are intricately linked and often codependent, dealing with them independently has often led to the environmental degradation of both natural and developed areas (Viessman, 1990). The challenge of developing an effective monitoring program and selecting key ecological indicators is to integrate all resources in order to provide quantitative assessments of the effects of pollutants and environmental change on all ecosystem components.

The North American Great Basin: A Sensitive Indicator of Climatic Change

Climatic change has become a major scientific and political issue during the past decade. Articles concerning global warming due to the greenhouse effect and ozone depletion from industrial chemicals are common in the news media and scientific literature. As stated by Schneider (1989), “the intense heat, forest fires, and drought of the summer of 1988 and the observation that the 1980s are the warmest decade on record have ignited an explosion of media, public, and governmental concern that the long-debated global warming has arrived”.

The Upper San Pedro River Basin

The San Pedro River begins in Sonora, Mexico, and flows northward through Arizona, United States, before joining the Gila River, which flows into the Colorado, and finally empties into the Gulf of California.… The Upper San Pedro River Basin in Sonora and Arizona is the focus of a number of urgent, complex, interrelated, and controversial issues, including its international importance as bird habitat, its attractiveness to development, and the vulnerability of its landscape to changes caused directly by development and indirectly via continued lowering of the groundwater table.

Wg Ii — Loss of Livelihoods and Increased Migration

After initial presentations on a European Commission funded research project on global environmental migration1 in 24 countries as well as some introduction into scenario development and alternative futures, participants discussed some of the issues related to migration. Migration is often not perceived to be caused by environmental reasons, not even by the migrants themselves. Indeed academically, the causal linkage is not fully established yet and should not be overstated. What is needed in this respect is more research on very specific case studies in the Mediterranean region, but also in sub Saharan Africa, since the southern Mediterranean countries are increasingly becoming transit countries. Outward migration is in fact a security issue, in the sense that one looses a lot of local knowledge of the land, and this loss is irreversible. It puts pressures on legal migration channels. However, it should also be noted that migration can have a very positive impact on destination and origin countries. This issue is the subject of a conference to be held in Rabat on 12–13 December 2007.

Summary, Conclusions, and Recommendations for Policy and Research

What are the human impacts of environmental change? How might land be used and what would be the potential benefits or consequences? Numerous questions arise as the world we know becomes smaller in our perception and the human population it supports becomes more dependent on the circumstances of a globalized economy. Increasingly, technology makes information instant and accessible to many. A first premise of the concept of security is that protection of human life from environmental, economic, food, health, personal, and political threats is a vital core value. A second argument is that actions that guard against environmental degradation represent a key element to security by ensuring sustainable resources and the continuation of providing ecosystem services that sustain human well-being. The human element of these premises, often partitioned as human security, and the ecosystem element is typically thought of as environmental security; both concepts, nonetheless, are so intrinsically interlinked that one term does not usually occur without the other. One goal of this scientific volume is to examine both human and environmental security and their linkages in the context of both natural and social sciences, in order to suggest strategies for reducing our collective vulnerability to pervasive threats. New global challenges await us in the near future, with