Human action has led to a vast cascade of environmental problems. They now pose a threat to the continued ability of both human and natural systems to flourish. Solving these critical environmental problems of water scarcity, global warming, biodiversity loss and pollution are perhaps the biggest challenges of the century. Will we rise to beat these challenges? Let’s dig in and find out more.
LEARNING OBJECTIVES
By the end of this topic, you are expected to;
- Understand the meaning of land reclamation and rehabilitation
- Understand the importance of land reclamation
- Know the different methods of land reclamation
- Know the methods of land rehabilitation
Land reclamation refers to the process of improving lands in order to make them suitable for more intensive use. The efforts of reclamation may concentrate on the irrigation of rainfall-deficient areas, removal of elements with detrimental effects, draining or diking of tidal marshes and other similar activities. Land rehabilitation refers to the process of restoring land to its former reproductive state.
IMPORTANCE OF LAND RECLAMATION AND REHABILITATION
- It intensifies the production of food to feed the ever-increasing population
- It helps to overcome the land shortage and pressure
METHODS OF LAND RECLAMATION
IRRIGATION. This refers to the artificial method of supplying water to a region that doesn’t receive enough rainfall to facilitate continuous crop production. Dams may be constructed in order to store water.
FACTORS DETERMINING THE AMOUNT OF WATER NEEDED FOR IRRIGATION
- Climate. More water is required for areas that receive low rainfall.
- Soils. Due to the low water retention ability of sandy soils, they require more water than clay soils.
- Crop. Some crops require waterlogged soils while others do not require so much water.
- Size of fields. Small amounts of water are required for small fields while large plots require large amounts of water.
METHODS OF IRRIGATION
- Water lifting method.
- Flood/basin irrigation. This involves diverting river water into a canal then to plots where it’s flooded.
- Sprinkler/overhead irrigation.
- Trickle irrigation.
- Canal irrigation.
CONTROL OF PESTS. Pests can have devastating effects on the activities of human beings. Some of the methods used in the control of pests include; spraying, fumigation, draining of stagnant water, poisoning, trapping, scaring away and hunting.
MEASURES TAKEN
- Bush clearing. Selective clearing of bushes can be applied to prevent soil degradation.
- Bush spraying.
- Sterilizing males.
- Creating buffer zones and
- The killing of the hosts.
METHODS OF LAND REHABILITATION
- Afforestation and reforestation. It improves the productivity of land in the following ways; controls soil erosion, vegetation reduces runoff, decayed vegetation provides humus, roots help moisture to percolate deeply into the ground and modification of the climate of an area by moisture that is released to the atmosphere causing higher rainfall and lowering the temperature.
- Bush fallowing. It involves cultivating a field for a period of 2-3 years then abandoning it for another in order for it to regain fertility naturally through wild vegetation adding humus to the soil.
- Grass strips and cover crops. Grass and cover crops like grass potato vines, peas, and beans reduce the speed of running water, therefore, helping to check soil erosion.
- Mulching. It involves covering the soil with crop residues or artificial materials like polythene sheets.
- Application of manure and fertilizer. Replenishing nutrients depleted from the soil by constant application of chemical fertilizers and manure.
- Other methods include; controlled grazing, filling quarries, drainage trenches flooded and planting drought-resistant crops.
