River Regulation - Biophysical Environments

RIVER REGULATION AND SUSTAINABLE DEVELOPMENTCASE STUDY OF THE HYDROSPHERE MR SHIPP NHSPA 2015

River regulation is the act of controlling river water level or the variability of river flows to meet human demands

The mains reasons are domestic, industrial, irrigational and energy supplies

Hint: The 3 main river systems we will use as examples are the Murray-Darling, The Three

Gorges Dam and the Aral Sea

Hint: Rivers are a crucial function that interacts with lithosphere and biosphere

The Key Biophysical Processes for Rivers

Precipitation falling at high points in the landscape will be divided at a watershed and flow downwards into a catchment zone

inputs - rain, snow

outputs - evaporation, into oceans, transpiration from plants or human use

FLOOD PLAINS AND RIVER CATCHMENT AREAS

Hydrological Function within the water cycle

Geomorphic Function mass movement of solid or soluble productions. Erosion along river banks

Ecological Function main source of life for animal/plant species

WHY RIVERS CURVE

Main terms to learn about Rivers Click here

River Processes Overtime

Case 1:Murray Darling River Management

Issues that have caused loss of water in the river

drought, climate change, population growth, storage of river regulation, irrigation

Under the Murray Darling Basin Plan, the Aust Govt aims to return 2,750 GL to the river system

click here

MURRAY-DARLING BASIN PLAN

Salinity

The release of salt from groundwater released into the river. Can decrease water quality and soil fertility.

Two major causes for the MDB: dryland salinity and irrigation-induced

Management: Sinking bores into groundwater taking out saline water or replanting of trees in farming areas

Impacts of River Regulation on the Spheres for the Murray Darling Basin

BACKLASH TO MURRAY DARLING BASIN PLANABC NEWS, 2010

Turbidity and Nutrient Runoff

The Cloudiness of Water. Natural processes of weathering and erosion cause increase to turbidity levels.

Important to manage turbidity as it reduces the ability from primary producers in the food chain to grow

Management: Soil Erosion of farming areas, monitoring of water quality after floods, replanting of trees along river banks

Habitat Change due to Dam Construction

Dams create deep, still and slow moving water

Dams and Weirs prevent the natural flow of water species

Fish species particularly the golden perch and murray cod have nearly become extinct

Management: Recreating in-stream habitats, restoration of wetlands, removal of introduced-species such as the European carp

Hint:It is important to include Government Strategies in any question that involves management in Geography

MURRAY DARLING AND THE WATER CYCLE

High Relief - V-Shaped Valleys, Low Relief - Floodplains, deltas and levees

Fluvial Landform Features

Braided Rivers

Found in high alpine areas due to short periods of high discharge

Meander

The repeated curves of the river channel

Oxbow Lakes/Billabongs

Meanders that continue to bend until two channels meet and break off. These dry out over and leave scars

Hydroelectric dam that spans the Yangtze River, China and is the worlds largest power station and hydroelectric facility

The Chinese Government regards it as a historic development that may lead to reduce of greenhouse emissions due to less coal producing required, lower threat of acid rain

Case 2:Three Gorges Dam

THREE GORGES DAM, CHINALARGEST HYDROELECTRIC DAM IN THE WORLD

1. Damage to local habitats e.g Chinese River Dolphin. Unable to swim upstream to spawn. Management: government to design artificial spawning reserves

2. Changes to the Water Quality due to dam construction, dissolved oxygen content

3. Loss of forest and agriculture clearing will increase erosion, decrease fertility of soil downstream and threat of landslides

Environmental Impacts

Displacement of 1.3 million people along the Yangtze River. Towns submerged under the reservoir

Impact to nearby towns to accommodate migrant workers

Farming communities downstream affected by pollution and loss of water supply

Social Impacts

Water diversions, agricultural practices, and industrial waste have resulted in a disappearing sea, salinization, and organic and inorganic pollution

Intensive problems discovered after the break up of the Soviet Union, 1991.

Management:The Agreement on Cooperation in the Management, Utilization and Protection of Interstate Water Resources was signed on February 18, 1992

Case 3:Aral Sea

The salt and mineral content of the lake rose drastically

Water unfit for drinking purposes and killing off the once-abundant supplies of fish species

More extreme winter and summer temperatures

Impacts

ARAL SEA MANAGEMENT AND IMPACTS