Sustainable management-Khushab, Pakistan

Context:

In Northern Pakistan and dependent on irrigation and agriculture.

Challenges:

1. Irrigation has not been managed well (has led to water-logging and a rise in the water-table)
2. As the water-table rises it brings up the soluble salts to the surface 
3. These salts are toxic to plants
4. 8,000 families incomes dwindled as agricultural productivity declined 

Solution:

• World Bank has invested $69million to reduce the water-logging and salinisation
• Installed PVC pipes to allow drainage underground
• Irrigation ditches have been lined to prevent seepage into the fields
• Farms are used to educate farmers about sustainable water management

Successful?

• Reduced water-logging by 50% in 2 years
• Improved incomes per capita from $46 in 1989 to $195 in 2005
• The average family is now 34% above the official poverty line.

Sustainable management-Great green wall, China

Where is the risk of desertification?

• Affects 1/3 of total land area
• Northern China most at risk as it is an arid, semi-arid and sub-humid region. (Korqin Sandy Lands)

Why are there desertification problems?

Physical:

1. High temperatures and strong winds
2. Sandy soils (highly permeable)=decreased water storage
3. Loosely structured (organic material)= increased erosion

Human:

1. Inappropriate farming practices (increased in the last 100yrs)
2. Population pressure (increased in last 100yrs)
3. Overgrazing
4. Clearing land for agriculture/timber
5. Increased irrigation (decreased water table)
6. Over-cultivated (increased deforestation)

Extent?

• China loses 5 billion tonnes of topsoil to erosion.
• Due to poor managed irrigation, 1 million km2 of land is saline.

Solution?

• To establish 350,000km2 of shelterbelt and plantation forests across North China by 2050.
• 3 main objectives:

1. To protect farmland and settlements from wind and water erosion.
2. To improve land management
3. To stabalise sand dunes and reclaim degraded land

• So far 130,000km2 have been planted.

Sustainable?

Social:

• Allows people to keep their way of life
• Boosts morale (government doing something)
• Trees are food crop, increased variety in the diet, healthier, increased Q.O.L
• Dust reduced in the air, increased health, decreased illness, increased Q.O.L

Economic:

• Crops are a source of income

Environmental:

• Makes climate less harsh by providing shelter, meaning the inter-connected food web is able to thrive.
• Shelterbelts modify micro-climates downwind.

Alternative?

Education:

• Emphasis on appropriate cultivation techniques. 
• Recycling of organic material in the soil.
• Integration of other crops.
• Planting specific tree species.

Sustainable management= It seeks to balance social, economic and environmental needs of a place.

Salinisation

Definition= The accumulation of salts (e.g. chloride, sulphate, carbonate, salts of sodium, calcium, magnesium) in the soil.

Why is it a problem?

1. Accumulated salt crusts may be difficult for plants to penetrate.
2. These salts are toxic to many plants.
3. They reduce the spaces available for moisture and air in the soil.

The Process:

• Salts are present throughout the soil but are not concentrated enough to damage plant life.
• Occurs where land has been cleared of trees and then irrigated without proper drainage.
• This causes the water table to rise nearer the surface lead to low vapour pressure in soil pores driving capillary action drawing moisture to the surface.
• SALTS ARE LEFT ON THE SURFACE AS A CRUST

Fact: 80% of irrigation projects in Uzbekistan have been lost to this process

Agriculture-Aral Sea

Location:

• Scale= 68,000km2 (in 1964)
• 60% lost 1964-1987
• 90% lost by 2002
• found between Uzbekistan and Kazakhstan
• Fed by the Syr Darya and Amu Darya (no longer fed by the sea)

Opportunities:

• Farmer used water for cotton (irrigation)
• Cotton (cash crop) successfully exploited

Challenges:

• Double salt concentration 
• Salinisation of the sea
• Collapse of fishing industry 
• Native organisms have died out 
• Lowering of groundwater levels
• Exposed sea bed (dustbowl contaminating land several hundred km inland)

What did the government do?

• Tried to introduce new fish species (doesn't tackle root problem)
• Cost-benefit analysis
• Reliance on cotton (refused to stop cotton industry)

The Kokaral Dam (completed in 2005)

• In 2003 Kazakh. government used money from oil exports to build the dam.
• Since 2005 North Aral water level has risen by 10m.
• Wider variety of fish returned.
• Now over 80 fishing boats operating in the sea.
• 2009= 2400 tonnes of fish caught
• Thriving fishing industry attracting people back (improved local services, more investment in agriculture)

Future of the Aral Sea

South Aral:

• Little hope of saving major part of Aral (fewer fish, more saline, more wildlife will die out)
• Continued desertification (Local climate will become more acute with colder winters and hotter, drier summers.

North Aral:

• 2nd Dam funded by World bank ($126 million) will bring water level back to the port of Aralsk, is still currently some 40km from the waters edge.

Future aims for aral sea basin:

1) Develop management strategies to give sustainable water use/sustainable land resource uses.

2) Improve information base (need to plan the development of water resources in the area

3) Stop/reduce deterioration of environment

4) Improve conditions (for people and animals living close to the sea)

Tourism-Skywalk

Context: 

• Grand Canyon, Utah
• Located away from the Grand Canyon Village (a honeypot site)
• Opened March 2004
• 1200m above canyon floor 
• cost £21 million to build (income shared by investor and Hualapai tribe)
• 70ft/20m from edge of canyon
• 4 million/yr tourists ($25 national park fee)

Opportunities:

• Exploitation/Commercialisation of culture
• Tourism
• Sustainable income helping local people (reduces the 50% unemployment rate, alcoholism, poverty)
• Positive multiplier effect
• Reduces overcrowding elsewhere (Grand Canyon Village)
• Profits go to a reconstructed Indian Village
• Better than a casino (causes less social problems)

Challenges:

• Conflicts with indigenous population
• Sacred ground to Hualapai tribe
• Delicate soil crusts 
• Aesthetically unpleasing on a unique landform 
• Water supply (Have to import at a high cost which is unsustainable)
• Not all members of Hualapai tribe benefit equally
• Lacks environmental sustainability
• New access road (air pollution/damage to soil crusts)
• Helicopter rides disturb wildlife/soil crusts impact

Exploitation= can be seen as the opposite of conservation-seeking economic gain usually at the expense of the environment.

Conservation= means keeping the landscape as it is - inhibiting any damage to the natural environment, so no economic development.

Urbanisation-Phoenix, Arizona

Context:

• Fastest growing state in the US (16% rise (2.5million) over the last 15-20yrs)
• Guaranteed sunshine (40°C)
• Cheap land (pediment)
• Surrounded by the Mojave Desert

Opportunities:

• Cheap land
• Guaranteed sunshine
• Urban development (profit)

Challenges:

• Isolated/Remote (Have to invest in infrastructure)
• Fragile due to cryptobiotic soil crusts
• Fragile ecosystem

Water landforms in arid environments

Case study: USA

1) Canyons 

2) Mesas, buttes, spires

3) Alluvial fans

4) Tafoni

5) Salt flats

1. Canyons

Ephemeral river= one that flows occasionally

Exogeneous river= permanent, originates in uplands outside of the arid environments.

Slot Canyons:

Location: Antelope Canyon 

• Canyons from ephemeral rivers 
• Made from one rock type
• Prone to flash floods as there is no vegetation

Key features:

• Narrower than it is tall
• Smooth sides 
• Sinuous 
• Uniform geology (Navajo sandstone)

Overland flow from where the local LP system breaks through the global HP system causing a flash flood. Due to limited interception and baked ground means there is a high amount of surface run-off. The overland flow picks up weathered material from wetting and drying, salt crystallisation, insolation/exfoliation, hydrolysis and freeze-thaw weathering. The weathered material abrades the sides of the canyon meaning there is a wider bottom than the sides.

Grand Canyon:

• Canyon formed with glaciation (relic landform)
• Stepped appearance
• Key processes: abrasion, hydraulic action

FACTS: 

1. Colorado river has had the same course for the last 6 million years.
2. River at deepest= 1600m

2. Mesas, Buttes, Spires

Location: Monument Valley

Shinarump cap rock (most resistant)

DeChelly sandstone (least resistant)

Organ shale (average resistant)

Parallel retreat= Occurs because rock debris is removed as fast as it accumulates.

3. Alluvial Fan

Location: Panamint Range, Death Valley, California

Increased friction means a decrease in energy leading to the deposition of sediment dropping the largest particles first.

4. Tafoni

Location: Snake Valley, Crystal Peak, Utah

Facts:

• 300m high
• Inselberg=crudely stratified
• rock type= porous & permeable (petrified volcanic ash)
• contains CaCO3 (calcite)

Definition= large hollows found in rock faces in semi-arid environments commonly <4m wide. They are a product of weathering (salt crystallisation).

Process:

1. Weakly acidic due to CO2 in the atmosphere is dissolved in the rainwater forming carbonic acidic.
2. Carbonic acid dissolves the calcite (Carbonation)
3. The evaporation of this leaves salt crystals of calcite in the pores of the rock. 
4. This causes the process of spalling leaving holes in the rock.

5. Salt Flats

Location: Bonneville Salt flats, Utah

Process:

1. High rates of evaporation bring salts to the surface
2. Surface run-off dissolves the salts running into the nearest lake or river
3. High temperatures lead to evaporation of the lake

Facts:

• 1.8m deep
• 4 levels are sodium chloride, sodium sulphate, sodium carbonate and calcium sulphate.