Assessment of River Ecosystems and Environmental Flows: Role of Flow Regimes and Physical Habitat Variables

The management of water resources across Australia is undergoing fundamental reform in line with the priorities identified by the Council of Australian Governments (COAG) in 1994. This includes reforms to the specification of property rights, the way the resource is shared between the environment, irrigators and other users, charges for water use and the operational management of the river systems. In New South Wales (NSW), a series of water sharing plans (WSPs) is being developed for each water source in the State including regulated rivers, unregulated rivers and groundwater aquifers. These plans, which are the mechanisms by which COAG reforms are being implemented, are being developed by community-based water management committees (WMCs). The role of the WMCs is to develop a plan that achieves a balance between environmental, economic and social outcomes. NSW Agriculture has assisted a number of WMCs by quantifying the economic impact of proposed WSP options on the irrigation community. This paper outlines the approach taken by NSW Agriculture to quantifying economic impacts on irrigators in regulated catchments and provides results of case studies in the Lachlan River Catchment which is heavily developed for irrigation.

Download Full-text

The role of dambos in determining river flow regimes in Zimbabwe

Journal of Hydrology ◽

10.1016/0022-1694(92)90042-t ◽

1992 ◽

Vol 134 (1-4) ◽

pp. 349-372 ◽

Cited By ~ 20

Author(s):

Andrew Bullock

Keyword(s):

River Flow ◽

Flow Regimes

Download Full-text

Application of the physical habitat simulation for fish species to assess environmental flows in an Atlantic Forest Stream in South-eastern Brazil

Neotropical Ichthyology ◽

10.1590/1982-0224-20140170 ◽

2015 ◽

Vol 13 (4) ◽

pp. 685-698 ◽

Cited By ~ 3

Author(s):

Marcus Rodrigues da Costa ◽

Tailan Moretti Mattos ◽

Victor Hugo Fernandes ◽

Francisco Martínez-Capel ◽

Rafael Muñoz-Mas ◽

...

Keyword(s):

Atlantic Forest ◽

Fish Species ◽

Habitat Suitability ◽

Environmental Flows ◽

Southeastern Brazil ◽

Microhabitat Use ◽

Physical Habitat ◽

Forest Stream ◽

Habitat Simulation ◽

Target Fish

ABSTRACT The physical habitat simulation sub-routine of the Instream Flow Incremental Methodology (IFIM) uses hydraulic modeling and suitability indices of target fish species to predict how differences in-stream flows affect the microhabitat occupation by fish species. This habitat modelling approach was adopted to assess the ecological effects of running flows on three neotropical fish species of different orders (Bryconamericus ornaticeps , Ancistrus multispinis and Geophagus brasiliensis ).The study encompassed two reaches of an Atlantic Forest stream in Southeastern Brazil where topographic and hydraulic (depth, velocity and type of substrate) characteristics were measured to implement one-dimensional hydraulic simulation. Sub aquatic observation of fish was performed to collect data on microhabitat use and these data were used to develop habitat suitability curves that were used in the habitat simulation to obtain the habitat suitability index (HSI) and weighted usable area (WUA) versus flow curves. Upon these curves minimum and optimum environmental flows for the target fish species were proposed. Bryconamericus ornaticeps and A. multispinis selected microhabitats around 0.6 m depth, whereas G. brasiliensis showed a wider suitable range (0.35-0.9 m). All the three species were mainly observed in microhabitat with low flow velocity (0.1 m/s). Bryconamericus ornaticeps selected more frequently coarse substrate (e.g. boulders) but it appeared also over sandy substrate, whereas A. multispinis and G. brasiliensis selected preferably boulders. The range of 0.65-0.85 m3/s was found as the optimum to meet the needs of the three fish species. Our results agree with the necessary objective information to perform grounded management actions in the frame of a management program aiming at ecosystem conservation. Thereby it can be considered a successful pilot study in environmental flow assessment in an Atlantic Forest stream of Brazil.

Download Full-text