49
from surface water in rivers and lakes. River corridors have been extensively modified to ensure that crop lands receive irrigation water when and where it is needed
and to ensure that water tables remain at levels necessary to sustain crops. Other
critically important components of water resources are household, municipal, and
industrial water supplies; wastewater treatment; river navigation; and flood control.
Recreational uses and subsistence fisheries, although economically and societally
important in some regions, generally receive less emphasis in water resources
management.
Simply stated, traditional water resources management has striven to (1) make
river corridors as physically simple and uniform as possible in order to ensure
downstream conveyance of flood waters and wastewater and to maintain navigation
and (2) control the downstream movement of water and sediment to ensure a steady
supply of water when needed and to stabilize channels and floodplains in a static
configuration. To these ends, the great majority of river corridors in the temperate
latitudes have been highly engineered via dredging, channelization, levees, flow
regulation, and land drainage. Consequently, there now remain almost no natural
river corridors around the world except at higher or lower latitudes. Despite the
enormous and ever-increasing cost of river and water resources engineering, one
can argue that this engineering has been successful in supporting the 174% expansion of irrigated agriculture that has occurred globally since the 1950s (Scanlon
et al. 2007) and the associated increase in global population from 2.5 billion in 1950
to 6.5 billion in 2005 (Bongaarts 2009). One can also argue that this success has
come at unsustainable cost to freshwater and nearshore ecosystems and that rates of
increase in global standard of living cannot be maintained unless much greater
emphasis is given to protecting and restoring river ecosystem services.
So how exactly can river engineering and management be altered to better sustain rivers as ecosystems that provide vital ecosystem services? This topic is the
focus of Chap. 4, but the short answer is by restoring more natural processes—spatial and temporal variability in water and sediment inputs—that in turn support
more spatially heterogeneous and changeable river corridors, with sufficient habitat
diversity and connectivity to support diverse biotic communities. Before exploring
this new vision of management in more detail, however, Chap. 3 provides a more
in-depth review of the history and types of human activities that have altered river
ecosystems.
References
Abbe TB, Montgomery DR (2003) Patterns and processes of wood debris accumulation in the
Queets River basin, Washington. Geomorphology 51:81–107
Arnaud F, Piegay H, Schmitt L, Rollet AJ, Ferrier V, Beal D (2015) Historical geomorphic analysis
(1932–2011) of a by-passed river reach in process-based restoration perspectives: the Old Rhine
downstream of the Kembs diversion dam (France, Germany). Geomorphology 236:163–177
Baartman JEM, Masselink R, Keesstra SD, Temme AJAM (2013) Linking landscape morphological complexity and sediment connectivity. Earth Surf Process Landf 38:1457–1471
References
from surface water in rivers and lakes. River corridors have been extensively modified to ensure that crop lands receive irrigation water when and where it is needed
and to ensure that water tables remain at levels necessary to sustain crops. Other
critically important components of water resources are household, municipal, and
industrial water supplies; wastewater treatment; river navigation; and flood control.
Recreational uses and subsistence fisheries, although economically and societally
important in some regions, generally receive less emphasis in water resources
management.
Simply stated, traditional water resources management has striven to (1) make
river corridors as physically simple and uniform as possible in order to ensure
downstream conveyance of flood waters and wastewater and to maintain navigation
and (2) control the downstream movement of water and sediment to ensure a steady
supply of water when needed and to stabilize channels and floodplains in a static
configuration. To these ends, the great majority of river corridors in the temperate
latitudes have been highly engineered via dredging, channelization, levees, flow
regulation, and land drainage. Consequently, there now remain almost no natural
river corridors around the world except at higher or lower latitudes. Despite the
enormous and ever-increasing cost of river and water resources engineering, one
can argue that this engineering has been successful in supporting the 174% expansion of irrigated agriculture that has occurred globally since the 1950s (Scanlon
et al. 2007) and the associated increase in global population from 2.5 billion in 1950
to 6.5 billion in 2005 (Bongaarts 2009). One can also argue that this success has
come at unsustainable cost to freshwater and nearshore ecosystems and that rates of
increase in global standard of living cannot be maintained unless much greater
emphasis is given to protecting and restoring river ecosystem services.
So how exactly can river engineering and management be altered to better sustain rivers as ecosystems that provide vital ecosystem services? This topic is the
focus of Chap. 4, but the short answer is by restoring more natural processes—spatial and temporal variability in water and sediment inputs—that in turn support
more spatially heterogeneous and changeable river corridors, with sufficient habitat
diversity and connectivity to support diverse biotic communities. Before exploring
this new vision of management in more detail, however, Chap. 3 provides a more
in-depth review of the history and types of human activities that have altered river
ecosystems.
References
Abbe TB, Montgomery DR (2003) Patterns and processes of wood debris accumulation in the
Queets River basin, Washington. Geomorphology 51:81–107
Arnaud F, Piegay H, Schmitt L, Rollet AJ, Ferrier V, Beal D (2015) Historical geomorphic analysis
(1932–2011) of a by-passed river reach in process-based restoration perspectives: the Old Rhine
downstream of the Kembs diversion dam (France, Germany). Geomorphology 236:163–177
Baartman JEM, Masselink R, Keesstra SD, Temme AJAM (2013) Linking landscape morphological complexity and sediment connectivity. Earth Surf Process Landf 38:1457–1471
References