Combating DesertificationHow far is desertification a feedback to human’s misuse of the natural resources in the semi-arid regions?

Misuse – in an unsustainable way

What resources?- Land- Water- Energy resources

Results: demands exceeding the carrying capacity

Misuse of the Land Resources 1

From pastoralism to sedentary cultivation & grazing in rangelands

Desertification sets in About 65% of dryland areas are rangelands Some suited to sustainable grazing than cro

p production

Results: inadequate fallowing for recovery

Misuse of the Land Resources 2

From free mobility to restricted movements Desertification sets in

Results: lower flexibility & adjustment of economic activity to meet disturbances and stress

Misuse of the Land Resources 3

From full control to threat of long-term security

loss of incentive for

maintaining

environmentally

sustainable practices

Results: Desertification sets in – vicious cycle!

Misuse of the Water Resources 1

From smaller households to large population

Great need to increase in food production Large-scale irrigation, tapping underground

water environmental crises

Misuse of the Water Resources 2

Environmental crises

e.g. water-logging & salinization, water

pollution, eutrophication,

over-exploitation of

groundwater aquifers

Results: degrading productivity of the land

Misuse of the Energy Resources 1

Destruction of vegetation in arid regions Often for fuelwood / firewood Leading to unprotected land

Results: Land degradation

Desertification – other factors?Other than human activities?

Desertificaton - Definition a process of turning the productive land into desert

a land degradation process that involves a continuum of change, from slight to very severe degradation of the plant and soil resource, and is due to human activities.

is also a situation on the desert expansion. That means desert is continuously expanding to the surrounding area.

Desertification

High pop. Poor / poverty

Climatic change

Over -cropping

Deforest- ation

Over -grazing

Global warming

Less PPT

↓ Soil fertility; soil degradation & Soil aridity

Human factors

+Impropriate irrigation

-salinization

∴infiltration >E underground water table rises salinization

What can we draw?

“If the climatic factors are said to be the main causes of desertification, then human activities are going to intensify it.”

Desertification & Climate Change

They are interlinked!

Desertification & Climate Change Long-term climate change (aridity)

Global warming rising temp lower soil moisture hinder condensation & rainfall drop of water table further drop of soil moisture loss of vegetation cover (protection) loss of organic matters less cohesive soil easy erosion by wind & water desertification climate change land degradation loss of vegetation higher CO2 emissions global warming lower evaporanspiration lower air humidity less & infrequent rainfall …..

Temporary / high magnitude drought periods in semi-arid areas

Effects of desEffects of desertificationertification

Atmosphere

-local climate

↓PPT

drought

-macro climate

global warming

Hydrosphere

-water cycle

breaks down

Lithosphere

-loss of arable

salinization

-land intensify the

soil erosion

Biosphere

-extinction of plants & animals

-↓biodiversity

Upset the balance of ecosystem

EffectsAtmosphere1) Micro (i)↓PPT+↑T° ↑T in day time &↓ T in night time↑ET/reflection ↑diurnal range of T° (ii) ↑wind speed no veg cover / shelter ∵ (iii) ↓relative humidity

2) Macro (i)Global warming (ii)Sandstormexpanding of desert

EffectsLithosphere

1)loss of arable land

soil texture change to sandy ↓cohesive

power (cannot hold water) not suitable for veg growth

2)intensify the soil erosion

1.↑ deforestationno root to bind the soil

↑ soil erosion↑ silting

EffectsHydrosphere1)Water cycle breaks down ↓∵ PPT & ↑ evaporation( no shelter)∵ rivers and wells dried up

Biosphere1)lower the bio-diversity ↓∵ PPT & unevenly dis.+deforestation scattered veg. (veg. Is shorter, few species, less luxuriant)extinction

Effects

Others1)lower the income

∵PPT ↓ crops productivity ↓

2)use a large amt of $ for soil protection & recovery

(i.e. UNCED US$1,100 m per yr to recover the deserted land)

What are the way out?Between LDCs & MDCs….

How to solve – In LDCs

1. Control the pop. growth / natural increase by using family planning, in order to decrease the land use capacity

2. The number of grazing and the rate of cultivation should not over the carrying capacity of land

How to solve – In LDCs

3. improve farming & grazing methods, to check reduce soil erosion and salinization

i) suitable timing and amount to carry out irrigation

plant the halophytes (which can adapt salty &

droughted soil) e.g. Chenopodiaceae

ii)sufficient fallowing period

animal welfare (e.g. Kenya)

How to solve – In LDCs

4. Legislation: ban the deforestation and over grazing, etc., in order to balance the ecosystem of desert.

5. Afforestation i.e. wind break trees & drought

resistant plants

6. Stone lines e.g. in Burkina Faso

7. Building reservoir and canal

e.g, The Indira Gandhi Canal

How to solve – In MDCs

1) international aid (e.g. Green Peace)

technology, low interest rate of loan &

education

2) scientific research

e.g World Association of Soil and Water Conservation (WASWC) 

How to solve – In MDCs

Both citizens in MDCs & LDCs have the

responsibility.

i) Don’t buy valuable halophytes (e.g. Fat Choi)

ii) 5R(reuse, reduce, renew, recycle, rethink)

iii) Fund raising

Effectiveness?

LDCs1)Money? LDCs are so poor

2)International aid? lack of technology,

efficient farming skill

& low education

3)Attitude? X family planning

Effectiveness?

MDCs1) Exploitation? try to get more raw materials

& resources from LDCs

2) Human behaviour?? rapid ↑in living

standard & large amt

of wastes are produced

MDCs

Remarks

The Recent Philosophy……

Remarks: “bottom-up approach” ~ drawing local communities to help:

(1) planning, decision-making & implementation

(2) empower those people who are most directly affected by desertification / those depend most on the land for their livelihood,

to become the initiators of projects

(3) enable local communities affected by these problems to understand properly the issues

*Take courage in formulating their unique solutions to the problems within their particular environmental & socio-economic conditions