Desert and desertefecation for asma bahusain

8/6/2019 Desert and desertefecation for asma bahusain

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Desert&

Desertification

Dr. Asma Ali Abahussain

Director, Desert and Arid ZonesSciences Program

Arabian Gulf University


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Contents Introduction

Desert

Types of Deserts

Desert Ecosystem

Land degradation and

Desertification of Drylands

Types of land degradation Desertification in Bahrain

Sand Dunes (Types, movements

and Fixation).


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Desert

Deserts are found in all regions, cover more than 40 percent of the Earth and are home to nearly 2 billion people-- one-third of the worlds population.

Desert is an area with a dry climate with less than 250mmof rain a year.


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Types of Desert

- Subtropical Desert are found around the

Tropics of Cancer and Capricorn.

- Deserts on Leeward side of major Mountain

ranges Rain shadow.

- Interior Deserts- center of continents far

from ocean Continental

- Coastal desert-prevailing onshore wind

cooled by cold ocean current

- Polar deserts- extremely cold and dry

The worlds major deserts like the

Sahara and the Kalahari.


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However, deserts may experience no rain at all for years, thenit receives a heavy downfall, or flash flood.


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Dryland are harsh dry environments, where few peopledryland peoples have succeeded in having sustainablelifestyles and management practices that maintain thedelivery of dryland ecosystem services.

Drylands are characterized by low rainfall (less than 100mmm)and high rates of evaporation (water stress).

nomadic pastoralism


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Dryland EcosystemsNevertheless many species of flora and fauna have adapted tolive in deserts, and they support a wide diversity of life.


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Drylandecosystemswith theirbiologicaldiversity

arefundamental to thelivelihoodsof the

people


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Ecosystem Services

The benefits people obtain from ecosystems

2005


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Provisioning Services

Food Crops

Livestock

Wild Foods

Fiber Timber

Cotton, hemp, silk

Wood Fuel

Genetic resources

BiochemicalsTraditional medicines

Freshwater

Goods produced or provided by ecosystems

Services of Desert

Ecosystem


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Regulating Services

Air Quality Regulation

Climate Regulation

Erosion regulation Water purification

Disease regulation

Pest regulation

Pollination

Natural Hazard regulation

Benefits obtained from regulation of

ecosystem processes

Services of Desert

Ecosystem


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Cultural Services

Knowledge Systems

Educational values Inspiration

Aesthetic Values

Social Relations

Sense of Place Recreation and

Ecotourism

Spiritual and Religious

(Meditation)

on-material benefits obtained from ecosystems

Services of Desert

Ecosystem


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Supporting Services

Nutrient Cycles

Soil Formation

on-material benefits obtained from ecosystems

Services of Desert

Ecosystem


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people living in drylands dependheavily on Ecosystems services fortheir basic needs.


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Dryland ecosystems are highly vulnerable to degradation

What is unique about Dryland Ecosystems ?

It is Easily disrupted, and slow to recover

he UN Convention to Combat Desertification defines desertification ahumid dry area-the degradation of the land in arid, semiarid and sub"

caused by various factors, including climatic changes and humaactivities

Desertification


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Consequences of Ecosystem Change forHumanWell-being

These ecosystem services are in declineas land is being degraded


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Aspects which involved in acceleration of land degradatio

ar OvergrazingOvergrazingPremature GrazingPremature GrazingEphemerals annualEphemerals annual


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Calligonum comosum

Wood harvestingWood harvestingPerennialsPerennials


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Desert AgricultureDesert Agriculture

Drylands contain 43 per cent of the worlds cultivated lands.

Land degradation causes an estimated loss of US $42 billion ayear from agricultural production. Nearly one-third of theworlds cropland has been abandoned in the past 40 yearsbecause erosion has made it unproductive. Each year an additional20 million hectares of agricultural land either becomes too

degraded for crop production, or.....

Agricultural

expansion in Saudi

Arabia utilizing

fossil groundwater


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Groundwater Quality

Deterioration Due to Over-

Exploitation

Saline Irrigation

Water

More IrrigationWater

Used For Leaching Salts

from Soil Top Layer

Further Soil Salinization &

Groundwater Quality

Deterioration

Water-logging Due to

Inefficient Irrigation Drainage

Arid Climatic Conditions

&

High Evaporation Rates

Desertification of

Agricultural Land &

Abandonment

Soil Salinization

Reclamation through leaching of excess salts increases water consumption,thereby putting additional pressure on the limited water resources.

Loss of Agricultural Lands By Groundwater Salinization


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becomes lost tobecomes lost to

urban spreadurban spreadoutout

1/12/2005


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?March 2004

Spring CampingSpring Camping

KuwaitKuwait


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Soil Salinization


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Water erosion

The loss of top soil

resulting in a decline infertility and thus in land

productivity.

Loss of biodiversity of

fauna and floraCollaboration of wind and water


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Dust storms are a growingproblem in many areas,affecting the health of

people and ecosystems bothlocally and at a greatdistance.

Sand Storm, 26 April 2005. Al Asad, IRAQ


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loss of top soil

Restoring soil lost by erosionis a slow process. It can take200 years for 1 cm of soil toform.


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S

Declining infiltration rates in the degraded and barren soilsreduce the seasonal availability and quantity of indispensablwater resources.Recurrent droughts reinforce this process of environmentalaridification.


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Wind erosion causes the encroachment and accumulation

of sands on productive rangelands and agricultural land,

urban areas and civil construction.


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IMPACTS

RESPONSES DRIVING

FORCES

PRESSURES

STATE

MACRO ECONOMIC

POLICIES

LAND POLICIES AND

POLICY INSTRUMENTS

CONSERVATION AND

REHABILITATION

MONITORING AND

EARLY WARNING

SYSTEMS

COMMITMENT TO

INTERNATIONAL

CONVENTIONS

INVESTMENTS IN LAND

AND WATER RESURCES

LAND PRODUCTIVITY

DECLINE

POVERTY AND MIGRATION

LAND GOODS AND SERVICES

WATER CYCLE AND QUALITY

CARBON STORAGE CAPACITY

DECLINEHABITAT DESTRUCTION AND

LOSS OF BIODIVERSITY

CHANGE IN HUMAN

POPULATION SIZE AND

SPATIAL DISTRIBUTION

OTHER OFF-SITE IMPACTS

LAND PRODUCTIVITY

DECLINE

SOIL DEGRADATION &

SOIL CONTAMINATION

SOIL EROSION

SOIL SALINIZATION

LOSS OF VEGETATION

COVER

LOSS OF BIOLOGICAL

DIVERSITY

.

DEMANDS FROM

SECTORS

AGRICULTURE,

URBAIN ...etc

NUTRIENT MINING

DEMANDS FOR

WASTE DISPOSAL

POPULATION

GROWTH

OVER CULTIVATION,

OVER GRAZING,

DEMANDS FOR

WATER USES

MACRO-ECONOMIC

POLICIES

LAND USE

DEVELOPMENT

POPULATION

GROWTH

POVERTY

LAND USE LAND

TENURE CONDITION

EXTREME CLIMATE

EVENTS/CHANGE

NATURAL DISASTERS

WATER STRESS

land degradationDPSIR framework for the Land Degradation Assessment in Dryland project (LADA)

The Land Degradation Assessment in Dryland project (LADA). LADA e-mail conference E-mail conference 9 th of October - 4 th ofNovember 2002

Desert and desertefecation for asma bahusain

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