17.3 Environmental Flow Assessment and Water Resources…
369
In recognition of the extensive knowledge often held by people with a connection
to their local river systems, about 30 structured interviews were conducted at various
locations throughout Taizhou. The interviews were focused on collecting information
related to fishery assets, particularly local knowledge about important fish and other
aquatic species in each of the defined river reaches; trends in the number and size of
different fish over time; fish diets and habitats; fish breeding patterns and times; fish
migration patterns; and any relationships between the above details and changes in
river flows, including during periods of drought and after typhoons.
The key fishery species identified were subsequently grouped into categories of
species with similar flow requirements; this was to simplify the process of identifying
environmental flow objectives for the basin.
(2) Vegetation assets
Background searches did not identify any specific information on riverine plant
species or communities in the Jiaojiang River Basin. Furthermore, no species related
to riverine systems were identified from lists of protected species at both the national
and regional levels.
While there are no formal nature reserves or protected areas encompassing riverine
habitats, an area of floodplain wetland was identified near the city of Linhai, immediately downstream of the confluence of Yong’an Creek and Shifeng Creek. This is
characterized by mixed woodland (including Populus sp.) with some open marshland. Useful background information on the ecology of riverine vegetation and its
relationship to river flows was obtained from a number of international publications
(Naiman and Decamps 1997; Nilsson and Svedmark 2002).
As specific vegetation-related environmental assets were not identified for the
Jiaojiang River Basin, the environmental flow objectives focus on the flows necessary to maintain existing riparian and wetland plant communities and provide
opportunities for recruitment through the maintenance of habitats.
(3) Geomorphology
Field assessments are conducted to determine the geomorphology of the rivers
and streams. Limited previous information that provided details about the geomorphology of the watercourses in the Jiaojiang River Basin was identified. As such, the
identification of geomorphological processes that support the local ecosystem and
the identified fisheries and vegetation assets involved on-site assessments at various
locations.
Bed material particle size was sampled at four sites in Reaches 1 and 3. The
results of these samples are depicted in Fig. 17.2. Zhu Creek is a cobble-coarse
gravel-bed river, with sand-sized material present within in the substrate. The creek
bed is actively mined for sand and gravel in many places. In the lower reaches,
downstream of Linhai City, the bed particle size changes to sand, while the estuarine
section has a mud bed (Guan et al. 2005).
The morphology of the river varies throughout the study area. In terms of overall
size, it increases as it progresses from the dam site toward the sea. Long pools of
369
In recognition of the extensive knowledge often held by people with a connection
to their local river systems, about 30 structured interviews were conducted at various
locations throughout Taizhou. The interviews were focused on collecting information
related to fishery assets, particularly local knowledge about important fish and other
aquatic species in each of the defined river reaches; trends in the number and size of
different fish over time; fish diets and habitats; fish breeding patterns and times; fish
migration patterns; and any relationships between the above details and changes in
river flows, including during periods of drought and after typhoons.
The key fishery species identified were subsequently grouped into categories of
species with similar flow requirements; this was to simplify the process of identifying
environmental flow objectives for the basin.
(2) Vegetation assets
Background searches did not identify any specific information on riverine plant
species or communities in the Jiaojiang River Basin. Furthermore, no species related
to riverine systems were identified from lists of protected species at both the national
and regional levels.
While there are no formal nature reserves or protected areas encompassing riverine
habitats, an area of floodplain wetland was identified near the city of Linhai, immediately downstream of the confluence of Yong’an Creek and Shifeng Creek. This is
characterized by mixed woodland (including Populus sp.) with some open marshland. Useful background information on the ecology of riverine vegetation and its
relationship to river flows was obtained from a number of international publications
(Naiman and Decamps 1997; Nilsson and Svedmark 2002).
As specific vegetation-related environmental assets were not identified for the
Jiaojiang River Basin, the environmental flow objectives focus on the flows necessary to maintain existing riparian and wetland plant communities and provide
opportunities for recruitment through the maintenance of habitats.
(3) Geomorphology
Field assessments are conducted to determine the geomorphology of the rivers
and streams. Limited previous information that provided details about the geomorphology of the watercourses in the Jiaojiang River Basin was identified. As such, the
identification of geomorphological processes that support the local ecosystem and
the identified fisheries and vegetation assets involved on-site assessments at various
locations.
Bed material particle size was sampled at four sites in Reaches 1 and 3. The
results of these samples are depicted in Fig. 17.2. Zhu Creek is a cobble-coarse
gravel-bed river, with sand-sized material present within in the substrate. The creek
bed is actively mined for sand and gravel in many places. In the lower reaches,
downstream of Linhai City, the bed particle size changes to sand, while the estuarine
section has a mud bed (Guan et al. 2005).
The morphology of the river varies throughout the study area. In terms of overall
size, it increases as it progresses from the dam site toward the sea. Long pools of