rural energy and land degradation major source of energy: crop (human) fodder (animal) fossils fuels...

Rural energy and land degradation

• Major source of energy:• Crop (human)• Fodder (animal)• Fossils• Fuels (coals, crude oil, natural gases)• Electricity; generated in hydro-station fossil fuelled • Nuclear• Solar • wind• Biomass (fuel-wood, crop residues, dung, biogas)

Rural energy

Traditional or non-commercial fuel include:• Fuel-wood• Animal dung• Stove• Charcoal• Crop residues• Biogas• Solar (direct sun energy)• Human energy• Draught animal

• 1/3 of all energy consumption in China derives from the non-commercial fuels

• ½ India

• ¾ Bangladesh

• 90% or more in SSA

Rural demography

• Majority low income countries population live in the rural areas – >90% in SSA– 4/5 in China and India– some 60% in Turkey

Rural energy major role

• Crop for human food

• Fodder for draught animal

• Cooking => 50% of total HH use

• Space heating => 30%

• Light

..Cont

• 15% - 20% for non-hh use

• Insect control

• Fruit and crop sun dried preservation

• Bricks and tiles production

• Cement and metal industry

• blacksmith

Contribution of Various Sectors to African Woodfuel Consumption for Different Reference Years (Million m3)

Year 1980 1985 1990 1994

Households 461.9 489.1 520.2 537.2

Industries 37.0 42.3 49.8 59.4

Fuel-wood contribution

• Fuel wood => 80% of rural HH energy– Cooking– Heating

• While charcoal – rural industry role

Contribution of Various Types of Woodfuels to African Woodfuel Consumption (million m3)

Year 1980 1985 1990 1994

Fuelwood 435.5 458.1 480.4 507.0

Charcoal 76.5 89.0 108.5 113.0

• (FAO), estimates that 37000 square kilometers of Tropical African forest disappear every year through forest clearing.– > Human popl. food production (agriculture)– Draught animal fodder – Fuel-wood

• Deforestation rate exceeds planting rate 29:1• 9 decades productive forests are expected to be

depleted.

Woodfuel Consumption According to the Best

Estimates* in Different Continents (1000 m3)

•   •    1980 1985 1990 Average annual

growth rate1980-90

Europe and non Europe OECD 451 504 488 0.8 %

Africa 514 549 592 1.4 %

Asia 636 711 788 2.2 %

Contribution of the Top 10 countries to African

Woodfuel Consumption in 1994 Rank Country 1000 m3 (%) of total African Consumption

1 Nigeria 118.8 19.1%

2 Ethiopia 56.6 9.1%

3 South Africa 42.5 6.8%

4 Tanzania 42.2 6.6%

5 Congo Democrat. Rep. 38.0 6.1%

6 Uganda 29.8 4.8%

7 Kenya 28.7 4.6%

8 Sudan 26.3 4.2%

9 Mozambique 21.7 3.5%

10 Cote d'Ivoire 19.0 3.0%

  Total 422.6 67.8%

Impact on environment

• Land is terrestrial bio-productive system that comprises:

• Soil• Vegetation• Other biota and,• Ecological and hydrological process that

operate with the system.• Any one of these components can be

affected by climate and/or human activity.

• Human activity– Over-cultivation– Overgrazing– Deforestation– Poor irrigation

• Climate – Prolong drought

• These are excessive pressure on resources ecosystems, fuelled by local forces– Increase in human popl.– Escalation of human needs– Poverty– Land shortages – Landlessness – Wars– Poorly conceived national policies (export production

vs crop production for local use)– Global economy– Debt burden

• SSA popl. *2 in the past 30 years => 708M (1994) & continue to expand;rate of 3%/yr

• Every year 21M people need food• Thus, > density + > popl. growth + rapid

urbanisation necessitate more land for crop production, fodder for draught animal, more wood for fuel.

• Over exploitation of land, forest, and pasture via over cultivation, overgrazing and deforestation will inevitably lead to soil erosion, i.e. land degradation.

• degradation = diminution or distraction of biological potential.

• Process of land degradation:– Long term distraction of vegetation– Diminution of many plants & animals popl.– H2O erosion– Wind erosion

• Soil erosion is believe to > in area, with little or no vegetation cover; e.g. maize yield have < from 6.5 t/ha to 1 t/ha due to erosion &/or loss soil fertility- Nigeria

Forest role

• Cumulus cloud are formed due to upward mvt of air (over forest) => start rain.

• Forests trap precipitation like fog, cloud & moisture.

• High permeability of forest soils enhances moistures balance and < risk of catastrophic floods

Org.M. & Humus role

• Organic matter helps hold the soil in place (vs rainfall & wind blows).

• Humus helps the soil to absorb and store water.

• Tropical soil appear to be thin & once exposed to the burning sun and rain => prone to erosion and loss of their structure and fertility.

• Live tree branches, shrubs and grasses were cut for fuel =>rob soil from protective & organic matter.

• Uproot crop residues for fuel after harvest have also contributed to degradation.

• Costly diversion of animal manure from food production (fertilizer) to cooking.

Manure and L. degradation

• Only in India 60 t. of dry animal dung is burned per year => robbing farmland of highly needed nutrients and organic matter.

• Loss nutrient, accounting to 1/3 of annual chemical fertilizer use in India.

• Thus damage to soil structure increases as the humus, organic matter and soil organisms which lives in it, play the role of preserving soil structure and fertility needed for production farming.

• Increase efficiency of energy use rather than energy supply

• Wood stove implementation =>40% to 50% energy saving than open fire with 60% smoke reduction.

• (-)ve, less heat and light• Require small pieces of fire (labour intensive)• Unsuitable for the local pots (problem of culture)

The substitute should be!?

• Technically efficient

• Finely viable

• Economically profitable

• Culturally acceptable

• Environmentally benign

summary

• Trees for fuel-wood and expansion of subsistence agriculture // to an ever > human popl. appears to lead to deforestation and subsequent land degradation.