Book contents
- Frontmatter
- Contents
- List of figures
- List of tables
- Preface
- List of abbreviations
- Conversions of selected units of hydrologic measurement
- 1 Water and Life
- 2 Challenge and opportunity
- 3 Unfolding recognition of ecosystem change
- 4 Natural waters
- 5 Plant–soil–water–ecosystem relationships
- 6 Groundwater
- 7 Lakes and wetlands
- 8 River channels and floodplains
- 9 Impounded rivers and reservoirs
- 10 Domestic and industrial water management
- 11 Decision processes
- 12 Integrative approaches
- Appendix: Guide to Internet resources on water and environment
- References
- Index
3 - Unfolding recognition of ecosystem change
Published online by Cambridge University Press: 05 October 2013
- Frontmatter
- Contents
- List of figures
- List of tables
- Preface
- List of abbreviations
- Conversions of selected units of hydrologic measurement
- 1 Water and Life
- 2 Challenge and opportunity
- 3 Unfolding recognition of ecosystem change
- 4 Natural waters
- 5 Plant–soil–water–ecosystem relationships
- 6 Groundwater
- 7 Lakes and wetlands
- 8 River channels and floodplains
- 9 Impounded rivers and reservoirs
- 10 Domestic and industrial water management
- 11 Decision processes
- 12 Integrative approaches
- Appendix: Guide to Internet resources on water and environment
- References
- Index
Summary
INTRODUCTION
Many of the challenges and opportunities articulated in international water assessments of the 1990s indicated a growing recognition of ecosystem changes generated by human water use. Much knowledge has been gained in recent years about the human effects on aquatic, riparian, estuarine, and groundwater ecosystems. Some effects, such as eradication of native non-commercial fish, purposely accelerated environmental impacts, while others have occurred with little or no recognition until illuminated by scientific or public inquiry (Gosnell, 2001). Assessment of habitat conditions, along with distinctions among levels of species endangerment, has become increasingly refined (IUCN, 2000). But many human effects on aquatic, amphibian, invertebrate, and fish species and their habitats still lie beyond comprehension.
Each year new surprises occur: an amphibious population declines, a waterbird species experiences birth defects, an exotic mollusk invades new waters, a fish disease spreads, an insect disease vector adapts to control methods. With sufficient time, the surprise is recognized, management alternatives are formulated, and actions are taken. For example, the adverse water quality effects of irrigation return flows from pesticide contamination in the Aral Sea basin of Central Asia, like increased selenium concentrations from irrigation return flows to the Kesterson Reservoir of California, have opened up new lines of environmental impact assessment and adjustments in irrigated areas of the world (Ghassemi et al., 1995; Kobori and Glantz, 1998; Micklin and Williams, 1996; NRC, 1989b). Remote sensing and aerial photography provide stark images of those impacts (Figure 3.1).
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- Information
- Water for LifeWater Management and Environmental Policy, pp. 26 - 46Publisher: Cambridge University PressPrint publication year: 2003