Coastal management
- Differentiate between hard engineering methods and soft engineering methods of coastal management
- Evaluate the success of coastal protection measures
- TYPES OF APPROACHES 2. Soft engineering approach (non-structural approach):
- Hard engineering approach (structural approach):
- the construction of physical structures to defend against erosive power of waves
- focuses on planning and management so that both coastal areas and properties will not be damaged by erosion
- aims at changing individual behavior or attitudes towards coastal protection by encouraging miminal human interference
- HARD ENGINEERING MEASURES
- SEAWALLS
- They are built along the energy of waves before hey can cause erosion
- They can be made of concrete, rocks or wood
- They are especially effective in protecting cliffs from erosion
- However they cannot prevent the back wash of the refracted waves from washing away beach materials beneath the walls
- This undermines the base of the seas=walls and they collapse
- Seawalls are costly to build and maintain
- BREAKWATERS
- It can be built with one and attached to the coast or away from the coast
- They break the force of high energy waves before they reach the shore
- When constructed offshore, it can create a zone of calm water behind them and allow deposition to occur, forming beaches
- Materials deposited behind the breakwater are protected but the zone located away from the breakwater its not
- It will not receive new materials and it will get eroded away.
- GROYNES
- They are built at right angles to the shore to prevent long shore drift
- They absorb or reduce the energy of waves and cause materials to be deposited on the side of the groyne facing the long shore drift
- However erosion can occur at places not protected by it
- GABIONS
- They are wired cages filled with crush rocks
- They are piled up along the shore to prevent or reduce coastal erosion by weakening wave energy
- It offers short-term protection (5 to 10 years)
- The cages require regular maintenance and are easily corroded by sea water, tramping and vandalism
- If not properly maintained, the wire baskets can be unsightly and dangerous along the beach
- SEAWALLS
- SOFT ENGINEERING MEASURES
- BEACH NOURISHMENT
- The constant replenishment of large quantities of sand to the beach system
- The beach is extended seawards, which leads to the improvement of beach quantity and storm protection
- It is costly to transport large quantities of sand to fill up the beach and sufficient sand is needed
- Sand being eroded and transported away by waves and wind and can affect wildlife e.g. coral reefs at Waikiki Beach in Hawaii
- RELOCATION OF PROPERTIES
- No beginning of properties are allowed in coastal areas vulnerable to coastal erosion
- The east coast of England ha a "green line" policy that discourage building located beyond it
- With the danger of increasing sea levels due to global warming, relocation is important to future coastal management
- PLANTING OF MANGROVES
- Mangroves with their prop roots help trap sediments and reduce coastal erosion
- As mangrove communities grow seawards, they extend the coastal land seawards
- STABILIZING DUNES
- access points to the beach should be controlled and designated so as not to be disturbed by human traffic
- Shrubs and trees can be planted to stabilize them. Roots of trees reach downwards to tap downwards to tap groundwater and anchor the sand in the process
- GROWTH OF CORAL REEFS
- Artificial reefs can be created by placing environmentally friendly and long-lived materials like steel or concrete on the sea floor
- Once the material is put in place, living organisms start to grow on it
- Man-made reefs are as productive as natural reefs in enhancing fishing oppppuronities and serve as undersea barriers to reduce impact of wave energy
- BEACH NOURISHMENT
- Seawalls:
- Advantages-
- absorb shock of waves
- reduce erosion of shore
- Disadvantages-
- erosion may lead to collapse of seawall
- costly
- Advantages-
- Breakwaters:
- Advantages-
- protect coast from high energy waves
- Encourage build up of beach
- Disadvantages- erosion on parts of coast not protected by breakwaters
- Advantages-
- Groynes
- Advantages-
- protect coast from high energy waves
- Encourage build-up of beach
- Disadvantages-
- erosion on parts of coast not protected by groynes
- Advantages-
- Gabions
- Advantages-
- weaken wave energy
- reduce coastal erosion
- Disadvantages-
- need regular maintenance
- Advantages-
WHat coastal STRATEGIES do we use in eastern Nc and WHy?
we use more soft engineering approaches than hard ones. Eastern North Carolina uses beach nourishment to save the look of the beaches so we don't change the look of the beach. Also, another reason we use soft engineering approaches is so we don't disturb wildlife or sea life from breeding and reproducing. For example sea turtles would have a hard time re-planting their nests if they had a huge breakwater or seawall in their way.
RANGE LAND management notes
WHAT IS A RANGE LAND?
- is uncultivated land dominated by native plants: grasses, herbaceous broad-leaves plants (forbs) and shrubs
- is all land that is not farmland, dense forest, barren desert or land covered by solid rock, concrete, or glaciers
- includes: grasslands, shrub lands, savannas, and open woodlands
- Are all range lands grazed?
- Grazing as an important ecological process in all range land, but not all range lands, but not all range lands are grazed by livestock
- Forest- 25%
- Cropland- 10%
- Urban- 3%
- Ice, rock & barren desert- 15%
- Rangeland- 47%
- 47% of the Earth
- 36% of the US
- 53% of the Western States
- 44% of Idaho
- In Idaho, 66% of all rangeland is "public Land"
- "Public Land" is owned and managed by federal and state governments for the good of the public
- In Idaho, the most important land management agencies are the Bureau of Land Management, the Us Forest Service, and the Idaho Department of lands
- Grazing on private lands is wholly integrated with public grazing land
- Livestock grazing occurs on 95% of BLM land
- and, 58% of the US Forest Service lands
- 88% of all beef cows in Idaho graze at least part of each year on BLM or USFS lands
- Livestock production
- wildlife habitat
- water
- minerals (oil, coal, sulfur)
- native plant products
- recreation
- open space
- western heritage
- Livestock Production
- rangeland & pastureland in the 19 western states are home to 58% of all beef cattle in the US
- Western rangelands also harbor 79% of sheep and 88% of goats in the US
- Livestock production on rangeland is very important to supply meat for American and World populations and also for leather, wool, mohair, and other products that livestock yield
- IS THE CAREFUL USE AND MANAGEMENT OF RANGELAND RESOURCES (PLANTS, ANIMALS, SOIL, AND WATER) TO MEET THE NEEDS AND DESIRES OF SOCIETY WITHOUT DAMAGING THE RESOURCE
- the tricky part is that the "needs and desires of society" are continually changing
- Livestock production has always been important but, greater management emphasis is now being placed on wildlife management, recreation, &water production
- INTEGRATED
- Fences
- The number of livestock can be increase or decreased to meet management objectives. Very heavy grazing may be required for some needs and light grazing is necessary for other purposes
- The species of livestock matters
- for example: cow generally prefer grasses, goats consume mostly shrubs or bushes
- And, different species of livestock also differ in type of terrain they use
- Invasion of weeds on rangelands is a growing problem. Range managers often need to use weed control
- Fire is a natural force in nearly all rangeland, fires are often carefully set and controlled
- RIPARIAN ZONE IS ALLOWING ONLY A PART OF AQUATIC RESOURCE TO BE AVAILABLE TO THE CATTLE
WHat is Rangeland worksheet
1. Western
2. grassland
3. Arizona
4. Bureau of Land management
5. Grassland
6. Rocky Mountains
7. canyons and rivers
2. grassland
3. Arizona
4. Bureau of Land management
5. Grassland
6. Rocky Mountains
7. canyons and rivers