Sonoran Basin and Range Ecoregion: Chapter 30 in <i>Status and trends of land change in the Western United States--1973 to 2000</i>

Abstract

This Professional Paper is the first multitemporal assessment of late-20th-century land change in the conterminous United States across all regions and all land-use and land-cover sectors. The work is the culmination of nearly 10 years of research and development by the U.S. Geological Survey, with support from the U.S. Environmental Protection Agency and the National Aeronautics and Space Administration, as well as university collaborators. It represents the most complete and comprehensive analysis of the rates, types, distribution, and drivers of recent changes in land use and land cover. The study bridges the gap between coarse-scale continental and global assessments and fine-scale local and regional case studies.Land-change studies attempt to explain the "what, where, when, how, and why" of changes to the vegetation and to the use of the land. Land-change research is aimed specifically at measuring where change is occurring (and where it is not occurring); which land-use and land-cover classes are changing (and what they are changing to); how much land is changing (and how fast); and what drivers are responsible for the measured changes. The goal is not only to understand the scope of change but also to provide the information base necessary to evaluate, predict, and manage the consequences of change.Like many key issues in climate change and ecosystem functioning, land use and land cover are both drivers and indicators of environmental quality. The National Research Council has identified the understanding of land-use dynamics as one of the grand challenges for environmental research-no other global-change parameter is so tightly intertwined with issues of past, present, and future land-use practices, weather patterns, soil and carbon dynamics, ecosystem health and diversity, economic development and policy, technology issues, human population size and distribution, and overall human health. People and their use of the land are interrelated in complex ways, and the effects of land-use and land-cover change can have a huge impact on their quality of life, on the goods and services that they can expect from the land, and on the hazards that they may face. Despite these profound consequences, the Intergovernmental Panel on Climate Change's Third Assessment Report has cited the lack of scientific understanding about the timing, magnitude, and direction of response of ecological, social, and economic systems to the combined effects of climate change and land-use and land-cover change as a key uncertainty in determining societal vulnerabilities and predicting both regional and global impacts of climate change.Prior to this study, only sectorally specific or spatially limited assessments and inventories had been conducted to categorize land change in the United States. These efforts often included only certain land-use and land-cover classes or ownership categories, or they were conducted over short time intervals only, and integrating these various assessments into a comprehensive and consistent national synthesi...

Detecting Streamflow in Dryland Rivers Using CubeSats

“…Land cover types, shown in Figure 1b, are shrublands (85.6%), forests (6.9%), grasslands (5.3%), urban areas (1.5%), and croplands (0.3%) in the National Land Cover Dataset (NLCD) 2019 product (Jin et al., 2019), and organized into two ecoregions: AZ/NM Mountains (ANM) and Sonoran Basin and Range (SBR, https://www.epa.gov/eco-research/ecoregions). ANM has higher elevations and receives more precipitation that feeds the perennial headwaters of HR (Ruhlman et al., 2012), while SBR is characterized by a warm and arid climate that is dominated by ephemeral streams (Calzia & Wilson, 2012). For jurisdictional evaluations of surface waters, the Arizona Department of Environmental Quality (ADEQ) divided the main stem of the HR at major confluences (Figure 1b).…”

“…epa.gov/eco-research/ecoregions). ANM has higher elevations and receives more precipitation that feeds the perennial headwaters of HR (Ruhlman et al, 2012), while SBR is characterized by a warm and arid climate that is dominated by ephemeral streams (Calzia & Wilson, 2012). For jurisdictional evaluations of surface waters, the Arizona Department of Environmental Quality (ADEQ) divided the main stem of the HR at major confluences (Figure 1b).…”