FORM 4 GEOGRAPHY

LAND RECLAMATION

Land reclamation is the process of converting wasteland into farmland for growing crops and keeping animals, while land rehabilitation is the process of restoring land to its former productive state.

Importance

• Intensify food production to feed the ever-increasing population.
• Overcome land shortage and pressure.

Methods of Land Reclamation

Irrigation

• Artificial method of supplying water to a region which does not receive adequate rainfall or to ensure continuous crop production.
• Done in dry areas with low rainfall and regions experiencing dry periods to sustain crop growth.
• Dams are used to store water.

Advantages

1. Can be used for hydroelectric power (HEP) generation.
2. Supports fish farming.
3. Supplies water for domestic use.
4. Controls floods.

Negative Effects

• Can cause deaths by drowning.
• Breeding ground for mosquitoes which transmit malaria.
• Breakage can cause destruction of life and property.

Factors Determining the Amount of Water Required for Irrigation

• Climate: Areas receiving low rainfall require more water.
• Soils: Sandy soils require more water than clays due to low water retention ability.
• Crop: Paddy rice requires waterlogged soils while vegetables require wet and well-drained soils.
• Size of fields: Small plots require small amounts of water while large plots require large amounts of water.

Methods of Irrigation

• Water lifting method

• Lifting water from a source using a bucket or watering can and pouring it on the crops.
• Used widely in market gardens and on farms adjacent to water sources.

• Diverting river water into a canal then to plots where it is flooded.
• Commonly used in irrigation schemes.

• Water is taken to the fields by pipes and applied on crops by rotating sprinklers mounted on vertical pipes.
• Used on golf courses and market gardening.

• Plastic pipes with holes laid in the fields through which water trickles to the base of plants.
• Popular where fruits and flowers are grown.

• Directing water through canals to farms.
• Commonly used in areas experiencing low rainfall, e.g., Yatta in Machakos.

• Inverting bottles filled with water into the roots of a plant.
• Used in low rainfall areas to grow trees, fruits, and flowers.

Drainage of Swamps

• Process of draining excess water from the land.
• Problems of land with excess water include:

1. Being a breeding ground for disease-causing vectors.
2. Waterlogging, making it unsuitable for agriculture.
3. Prone to flooding which destroys life and property.

Processes Involved

• Digging ditches for water to ooze into and flow away by gravity.
• Planting eucalyptus which absorbs a lot of water, e.g., at Kakuzi in Makuyu.
• Laying perforated pipes in ditches through which water seeps and flows away by gravity.

• Areas in Kenya reclaimed by draining include:
  • Yala on lower courses of River Yala.
  • Bunyala on lower courses of River Nzoia.
• The project was conceived in 1970.

Objectives of the Project of Draining Them

1. Free the area of pests.
2. Prepare land for settlement and agriculture.
3. Ease population pressure on Kano plains.
4. Reduce flooding and associated hazards.
5. Develop the otherwise remote area.

Achievements

1. Flooding has been controlled.
2. About 800 hectares are available for agriculture and settlement.
3. Waterborne diseases have been brought under control.

Control of Pests

Mosquitoes

1. Fumigation.
2. Draining of stagnant water.
3. Spraying.
4. Clearing of bushes near settlements.

Rodents, Birds, Squirrels, and Porcupines

• Trapping.
• Poisoning.
• Hunting.
• Scaring away.

Tsetse Flies

• They thrive in damp areas with high temperatures and prefer bushy vegetation as breeding grounds.
• Examples of tsetse fly-infested areas are Lambwe Valley in Kenya and Miombo woodland in Tanzania.
• The control of tsetse fly at Miombo woodland was aimed at:
• The control was done by The International Centre for Insect Physiology and Ecology (ICIPE).
• Eliminating the pest to obtain land for agriculture.
• Treating sick people and animals to check the spread of resultant diseases.

Measures Taken

Bush Clearing

• Selective clearing of bushes to prevent soil degradation.
• Caused tsetse flies to lack breeding places and killed adult flies and pupae due to low humidity.

Bush Spraying

• Spraying from the ground or from a low-flying aircraft.
• Does not affect other organisms.

Disadvantages

• Some insecticides such as DDT have serious environmental effects.
• The fly develops resistance, requiring higher doses of chemicals.
• Kills other useful organisms.

Sterilisation of Males

• Making the insect unable to reproduce by obstructing its reproductive organs.
• Luring male flies to a chemical substance that sterilizes them.
• When they mate with females, fertilization does not occur, reducing insect population.

Traps

1. Square of black cloth coated with glue on which the insects stick.
2. Traps impregnated with insecticides which kill the insects.

Creation of Buffer Zones

Belt of 5 km wide with dense cultivated vegetation to create a barrier which the fly cannot cross.

Killing of the Hosts

Wild animals which the fly fed on were selectively hunted and killed.

Methods of Land Rehabilitation

Afforestation and Reafforestation

• Improve land productivity in the following ways:
• Control soil erosion by:
• Acting as windbreakers.
• Leaves reduce the impact of raindrops on the soil.
• Roots hold/bind soil particles together.
• Vegetation reduces runoff and increases infiltration of rainwater, ensuring a complete water cycle.
• Decayed vegetation provides humus which restores soil fertility.
• Roots help moisture percolate deeply into the ground.
• Modify the climate by releasing moisture to the atmosphere, causing higher rainfall and lowering temperature.

Bush Fallowing

• Cultivating a field for 2-3 years then abandoning it to regain fertility naturally by wild vegetation adding humus to the soil.

Grass Strips and Cover Crops

• Grass and cover crops (e.g., sweet potato vines, beans, peas) reduce the speed of running water, helping to check soil erosion.

Mulching

• Covering the soil using crop residues or artificial materials such as polythene sheets.
• Helps conserve soil by:
• Reducing evaporation, conserving moisture.
• Checking the speed of running water.
• Reducing the splashing effect of raindrops.
• Reducing runoff and increasing infiltration, ensuring more moisture for plant growth.
• Mulch from crop residues decomposes, releasing nutrients into the soil.
• Controlling weeds.

Application of Manure and Fertilizer

• Replenishing nutrients depleted from the soil by constant application of manure or chemical fertilizers.

Controlled Grazing

To solve overgrazing:

• The government advises farmers through extension officers on matching livestock numbers with land carrying capacity.
• Emphasizing quality over quantity by introducing exotic breeds and crossbreeds.
• Establishing ranches in livestock farming regions, e.g., Kaptuei group ranch.
• Subdividing land into paddocks so different sections can regain pasture at different intervals.

Filling Quarries

• Filling pits with rocks and topping with fertile soil, e.g., Bamburi Nature Trail where trees have been planted and animals introduced.

Drainage Trenches

Flooded areas can be rehabilitated by:

• Digging trenches to drain excess water.
• Constructing dams across rivers.

Planting Drought-Resistant Crops

• Planting drought-resistant and quick-maturing crops in Arid and Semi-Arid Lands to take advantage of the short wet season, e.g., pigeon peas, cassava, millet, sorghum, Katumani maize.

Irrigation Schemes in Kenya

Mwea Irrigation Scheme

• Located in Kirinyaga district in Central Province on the Mwea plains at the foot of Mt. Kenya.
• Started by the colonial government in 1954.

Objectives

1. Reclaim unproductive land from semi-arid conditions.
2. Occupy detainee labour since Mwea was a detention camp for political detainees during the 1952 state of emergency.
3. Settle former detainees and the landless.
4. Create employment for former detainees.
5. Increase agricultural production.

Factors Which Influenced the Location of the Scheme

Physical Factors

1. Availability of extensive land allowing future expansion.
2. Black cotton soils with high water retention suitable for rice growing.
3. Freely draining clay loamy soils suitable for other cash and food crops.
4. Gently sloping land allowing use of tractors and gravity flow of water, reducing pumping costs.
5. Plentiful water from permanent rivers Thiba and Nyamindi draining the area.
6. Warm weather during the second part of the year suitable for rice growing.

Human Factors

1. Land was uninhabited due to arid conditions, so no displacement occurred.
2. Availability of labour for rice growing due to presence of former detainees.
3. Desire by the colonial government to start a project to occupy detainees.
4. Location near major urban centres such as Nairobi, Embu, Nyeri, and Kerugoya providing immediate market for rice.

Irrigation/Cultivation Method Used

• Basin irrigation

• Ground is levelled.
• Embankments are constructed.
• Water is supplied to enclosed sections.
• Paddy fields are flooded to a depth of 10 cm.

• Water flows from irrigation canals to furrows between rows of crops, wetting them.

Crops Grown

1. Wet paddy (rice):

1. Basmati/Pishori, which is more valuable.
2. Sindano, which is resistant to diseases.

2. Subsistence crops such as maize, peas, and beans on a small scale.

Horticultural crops such as tomatoes, French beans, melons, etc.

Organization of the Scheme

• Divided into Mwea, Thiba, Wamumu, and Tebere sections.
• 6000 hectares under rice cultivation.
• Tenants live in 36 small villages.
• There are 17 primary schools, more than 5 secondary schools (one for disabled), and one mission hospital (Karira).
• Rice cultivation plots are one-acre each, surrounded by earth bunds to keep water within the field.
• Each tenant is given 4 acres and expected to maintain a nursery covering 1/8 of an acre.

Marketing

Farmers sell rice to local consumers in urban centres, especially Thika and Nairobi.

Benefits of the Scheme

1. Saves foreign exchange by contributing most of Kenya’s rice production.
2. Provides income to farmers and traders, alleviating poverty and raising living standards.
3. Provides land to thousands of landless people.
4. Reservoirs help control flooding.
5. Improves infrastructure, with roads built to transport rice to market.
6. Provides social amenities such as schools and hospitals, improving living standards.
7. Provides employment on farms, local mills, and trading.

Problems Facing the Scheme and Possible Solutions

Stagnant water has become a breeding ground for mosquitoes and snails transmitting malaria and bilharzia.

Insecticides should be sprayed on stagnant water to reduce vector breeding and infection rates.

Shortage of water due to droughts and diversion to ‘Jua Kali’ rice farms.

More reservoirs should be built; farmers should pay fees for water distribution maintenance.

Pests and diseases such as caseworm and leaf miner attack crops, lowering yields; Quelea birds feed on rice causing major losses.

Use clean planting seeds, burn residues after harvesting, and use explosives to scare birds.

Inadequate capital due to cooperative collapses prevents farmers from acquiring inputs, forcing leasing of farms.

Solution: remove politics from cooperatives to empower them to supply inputs and credit.

Shortage of labour during planting and harvesting forces farmers to hire expensive labour.

• Improved marketing by NCPB to help farmers earn enough to meet expenses.
• Siltation and weed growth in canals interfere with water flow.
• Control weeds using chemicals; farmers should avoid cultivating river banks.
• Inadequate health centres require long travel, losing working hours.
• Construct more health centres.
• Poor access roads make transport expensive.
• Government should improve existing roads and build new ones.

Perkerra Irrigation Scheme

Established in 1954.

Located in Marigat division in Baringo, Rift Valley province.

Aims of Setting up the Scheme

1. Utilize detainee labour.
2. Develop land for agricultural production.
3. Settle pastoralists as farmers.
4. Control seasonal floods of River Perkerra.
5. Utilize excess water of River Perkerra that was wasted.

Factors Which Influenced the Establishment of the Scheme

Physical Factors

Gentle slope allowing mechanization and gravity flow of water.

Fertile loamy soil suitable for various crops and reducing fertilizer use.

Semi-arid conditions necessitating irrigation for food production.

Extensive land area allowing large-scale cultivation.

River Perkerra providing constant water supply.

Human Factors

Sparse population due to harsh climate facilitating scheme establishment.

Large detainee population requiring productive occupation.

Colonial government desire to occupy political detainees.

Irrigation/Cultivation Method

• Ridges and furrows are made.
• Crops planted on ridges.
• Water directed to furrows and allowed to soak slowly.
• Seed maize planted in male and female lines.
• Maize from male lines is for consumption.
• Maize from female lines is for processing.

Crops

Seed maize for Kenya Seed Company; pawpaws are gradually being reintroduced.

Organisation of the Scheme

Managed by NIB, providing infrastructure, accounting, and extension services.

Each household allocated 3-4 acres plus ½ acre for homestead.

Farmers are tenants; plans underway to issue title deeds.

Marketing

• Seed maize graded, dried, and delivered for shelling.
• Shelled maize delivered to Kitale for processing.
• Seed delivered to KSC, which pays on delivery.
• Scheme management pays farmers after deducting service fees.

Achievements of the Scheme

Turned arid land into productive land.

Source of livelihood for farmers and dependents.

Seed maize raises government revenue.

Settled previously landless people.

Improved infrastructure and social amenities such as schools, shops, electricity.

Created employment opportunities.

Source of foreign exchange through seed maize export.

Problems of the Scheme and Possible Solutions

• Water fluctuation in River Perkerra due to droughts and obstructions reduces cultivated acreage.
• Dam construction upstream.
• Livestock-human conflict over grazing due to attractive vegetation.
• Conflict resolution through elders.
• Ethnic conflict between Tugen and Jemps tribes; government to issue title deeds.
• Financial problems prevent land preparation; start cooperatives for affordable credit.
• Poor transport and communication hinder perishable crop production; improve roads.
• Limited market due to sparse population; transport produce to denser markets.

Significance of Irrigation Farming in Kenya

1. Resettlement of landless people, e.g., in Mwea.
2. Made barren land productive.
3. Enables farmers to earn income from farm produce sales.
4. Provides employment, alleviating poverty and improving living standards.
5. Creates settlements for landless.
6. Earns foreign exchange through export of chillies, flowers, peas, fruits, etc.
7. Saves foreign exchange by reducing food imports.
8. Develops infrastructure and social amenities such as roads.
9. Promotes industrial development by providing raw materials (rice mills, pineapple processing, sugarcane factories).
10. Assists in controlling environmental hazards like droughts and floods.
11. Enhances food security by encouraging food crop production (maize, beans, rice).

Problems Experienced in Irrigation Farming in Kenya

Physical Problems

Crop destruction due to flooding from excess water.

Pests and diseases reduce cotton yields.

Inadequate water from unreliable rainfall in catchment areas limits land use.

Weed growth in furrows and canals reduces water flow.

Silting of canals impedes water flow.

Sheet erosion from overhead irrigation in hot, dry regions.

Salinisation from excess water application in dry regions.

Leaching removes nutrients to lower soil horizons, reducing yields.

Human Problems

1. Diseases like bilharzia and malaria transmitted by vectors in stagnant water weaken or kill farmers.
2. Low prices paid to farmers reduce morale and cause leasing out of farms.
3. High production costs lead to high produce prices, reducing competitiveness in world markets.
4. Soil nutrient exhaustion from continuous cultivation causes poor yields.
5. Mismanagement of irrigation bodies causes losses, lack of credit, and low prices as farmers market individually.
6. Few extension officers limit technical advice to farmers.
7. Labour shortages during planting, weeding, and harvesting force costly hired labour.
8. Limited markets due to sparse populations near some schemes, e.g., Perkerra.

Land Reclamation in the Netherlands/Holland

• Most coastal land has been reclaimed from the sea.
• Land reclaimed from the sea and enclosed by walls is called a polder.
• Reclamation was done under two main projects:

Zuider Zee Project

• Project in the Zuider Zee area north of Holland.
• Assigned to Dutch engineer Cornelius Lely (1927-1932).
• Aimed to increase land for cultivation and control flooding.

Sections

• Creation of a high dam across the highland of Wieringen between North Holland and Friesland.
• Reclamation of 4 polders safe from tides and creation of a freshwater lake from River Ijsel, converting the tidal sea into Lake Ijsel.

Stages in Reclamation of Land from the Sea in Netherlands

• Dykes constructed to protect land from high tide flooding.
• Ring canals built to carry water from reclaimed area to the sea.
• Pumps installed to remove water from enclosed areas.
• Reeds sowed to absorb excess water.
• Drainage pipes laid in ditches to drain water from the water table.
• Soil treated with chemicals to reduce salinity.
• Drained land flushed with fresh water to remove salt.

Benefits of Zuider Zee Project

• Increased arable land by 10%.
• Freshwater lakes provide water for domestic and industrial use.
• Improved drainage for reclaimed area.
• Reduced flooding risk.
• Shortened road connection between North Holland and Friesland.

Delta Plan Project

• Intended to reclaim southwest region of the country.
• Involved closing estuaries (Haringvliet, Brouwersha, Venschegat, Scheldt, Veersche) by dams.

Benefits of the Delta Plan

• Controlled pollution and salinisation of inland water.
• Improved soil, increasing land for agriculture.
• Created recreational lakes.
• Freshwater reservoirs provide water for irrigation, domestic, and industrial use.

Comparison of Land Reclamation in Kenya and Netherlands

Similarities

• Flooding was a common problem in both countries.
• Drainage ditches were used in both.
• Canals were used in both.
• Both aimed to increase land for settlement and agriculture and control flooding.

Differences

• Netherlands used canals, dams, and dykes; Kenya used ditches, irrigation, and bush clearing.
• Netherlands reclaimed land from the sea; Kenya reclaimed land above sea level.
• Netherlands had two major projects; Kenya had more.
• Netherlands reclamation was large scale; Kenya’s was small scale.
• Netherlands used advanced technology (dams, dykes, pumping stations); Kenya used less advanced methods (irrigation, afforestation, bush clearing).
• Netherlands reclaimed coastal land; Kenya reclaimed inland land.