Soil Reclamation

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Soil reclamation (Land reclamation)

Soil reclamation is the process of improving lands to make them suitable for a more intensive use. Reclamation efforts may be concerned with the improvement of rainfall-deficient areas by Irrigation, the removal of detrimental constituents from salty or alkali lands, the diking and draining of tidal marshes, the smoothing and revegetation of strip-mine spoil areas, and similar activities.

Reclamation methods

Dry method

The dry method is suitable for filling material from land sources, especially rock, hillcut and clay fill. Filling or transporting clay fill material into the sea would create viscous slurry which would take much longer to become usable land. As explained earlier, the dry method usually uses a truck or conveyor belt to transport fill material to extend the land towards the sea.

Generally, the dry method works well for foreshore locations with underlying competent seabed soil. If the seabed soil is weak, a mud wave will be created in front of the fill because of displacement. In that case, a greater quantity of fill material would be required. In addition, the dry method usually results in a loose profile of fill especially when granular soil is used as fill material.

A comparison of the density profile of granular fill carried out by hydraulic filling and land filling is shown in Figure 6.1. It can be seen that the density profile of landfill is much lower than hydraulic fill. Therefore, landfill generally requires densification of granular soil.

Hydraulic reclamation

A wet method of reclamation is implemented when fill material is obtained from an offshore borrow source. However, this method is only suitable for granular fill, which has good drainage characteristics. As explained earlier, the method of filling is selected based on the availability of equipment, type of seabed soil, topography of seabed, and the production rate required.

Direct dumping

A direct dumping method is used when the seabed is deep or the underlying seabed soil is soft. A bottom-opening barge usually carries fill material from the borrow source and either sails with a self-propeller or pushed by the powerful tugboat to the designated location. At the location, fill material is dumped by opening the bottom of the barge. Sufficient draft and clearance is required for this method. Generally, a seabed of 6 – 8 meters depth is suitable for bottom dumping. This method is used not only for granular material but also for stiff clay and soft clay. However, dumping of soft clay is not appropriate for deeper seabed conditions since soft clay can be dispersed, and the Environment can be affected. Bottom-opening barges usually have a capacity of a few thousand cubic meters and the production rate of reclamation using bottom-opening barges is largely dependent upon the number of barges used and the distance between the borrow sources and the reclaimed area. The dumping location is generally controlled by a global positioning system. However, bottom dumping alone cannot complete the reclamation because it can only operate up to 2 – 3 meters depth below sea level. The next level of fill has to be raised by hydraulic filling or other means.

Rehandling from a rehandling pit

Sometimes, if cutter suction hopper trailers are not available or direct dumping is not feasible, a rehandling method is used. The rehandling method involves transporting sand by barges and dumping the fill material temporarily in the pit for storage. The pit should have a storage capacity of a few million cubic meters. Rehandling pit locations are generally selected at natural depressions on a firm seabed or created by dredging. To create a rehandling pit, one needs to consider the stability of the pit slope. Such an operation would require two stationary cutter suction dredgers, one at the borrow source and another at the rehandling pit. In that case, sand barges are required to transport sand to the rehandling pit. Alternatively, one cutter suction hopper dredger dredges the sand at the borrow source and transports it to the rehandling pit, while another stationary cutter suction dredger will operate at the rehandling pit to fill the reclamation area.

Hydraulic filling

The hydraulic filling method is suitable for granular fill. Generally, this method is used when filling is carried out from an offshore source, either from a rehandling pit, as explained earlier, or from a trailer suction hopper dredger. In the case of pumping from a cutter suction hopper dredger, the fill material is dredged from the borrow source with its own trailer suction dredger which is moved adjacent to the reclamation area and then pumped through the discharge pipe. Bulldozers are used to grade and spread the fill material around the discharge pipe. The discharge pipe is usually set slightly above the required finished level. Pumping is usually done with a mixture of fill material and water. The ratio of fill material to water is adjusted according to the grain size of the fill material. A large ratio of material to water would lead to wearing of the inner walls of the sand transportation pipe. On the other hand, a smaller ratio of material to water will reduce the production rate. After a certain amount of land has formed, the pipes are extended accordingly. Usually, the diameter of the sand transportation pipes is about 800 – 1000 m and 10 meters in length. Normally, wearing occurs at the bottom of the pipe, therefore, frequent rotation of the pipe after usage is necessary. Pipes that have to run above water can be floated with floaters attached to the pipes.

Sand spreading

Sand spreading is implemented when a shallow seabed is encountered or when the seabed soil is too soft. When sand spreading is carried out, a rehandling pit is generally necessary. The spreader is mounted on a small floating barge. The end of the discharge pipe is usually closed and several perforations are provided along the last two to three sections of the discharge pipes. Sand is discharged through the perforations with water.

Pumping inside the bunds

Reclamation can start from the coastal line and advance towards the sea. However, this type of reclamation may lead to great loss of fill material because of wave and current action. Therefore, sometimes reclamation is carried out within a protected area after a bund has been formed around the proposed reclamation area. In this way, losses caused by wave and current action can be minimized. However, this type of reclamation requires an outlet for the overflow of water and fine material, otherwise mud can be trapped at or near the corner of the bund.

Soil reclamation is the process of restoring land that has been damaged by human activity or natural disasters. It can be used to restore agricultural land, wetlands, forests, and other types of Ecosystems.

Soil erosion control is one of the most important aspects of soil reclamation. Erosion is the process of soil being carried away by wind or water. It can be caused by a variety of factors, including deforestation, agriculture, and construction. Erosion can lead to a loss of topsoil, which is the most fertile layer of soil. It can also damage water quality and increase the risk of flooding.

There are a number of ways to control soil erosion. One way is to plant trees and other vegetation. Trees and other Plants help to hold soil in place and prevent it from being eroded. Another way to control erosion is to use terracing. Terracing is a method of farming that involves creating a series of raised beds. This helps to slow down the flow of water and prevent erosion.

Soil fertility management is another important aspect of soil reclamation. Soil fertility is the ability of soil to support plant Growth. It is determined by a number of factors, including the amount of organic matter in the soil, the pH level of the soil, and the presence of nutrients.

There are a number of ways to improve soil fertility. One way is to add organic matter to the soil. Organic matter helps to improve the structure of the soil and increase its ability to hold water. Another way to improve soil fertility is to add nutrients to the soil. Nutrients can be added in the form of Fertilizers or manure.

Wetland restoration is the process of restoring wetlands that have been damaged by human activity or natural disasters. Wetlands are areas of land that are saturated with water. They play an important role in the environment by filtering water, providing habitat for wildlife, and preventing flooding.

There are a number of ways to restore wetlands. One way is to plant native plants in the wetland. Native plants help to improve the water quality of the wetland and provide habitat for wildlife. Another way to restore wetlands is to remove invasive species. Invasive species are plants or animals that are not native to an area and can harm the environment.

Forest restoration is the process of restoring forests that have been damaged by logging, fire, or other disturbances. Forests play an important role in the environment by providing habitat for wildlife, regulating the Climate, and preventing soil erosion.

There are a number of ways to restore forests. One way is to plant trees. Trees help to improve the air quality and provide habitat for wildlife. Another way to restore forests is to prevent wildfires. Wildfires can damage forests and make it difficult for them to recover.

Ecosystem restoration is the process of restoring entire ecosystems that have been damaged by human activity or natural disasters. Ecosystems are communities of plants, animals, and other organisms that interact with each other and with their environment. They play an important role in the environment by providing food, water, and shelter for wildlife.

There are a number of ways to restore ecosystems. One way is to plant native plants. Native plants help to improve the water quality of the ecosystem and provide habitat for wildlife. Another way to restore ecosystems is to remove invasive species. Invasive species are plants or animals that are not native to an area and can harm the environment.

Soil reclamation is a complex and challenging process, but it is essential for protecting our environment and ensuring the sustainability of our food system. By restoring damaged land, we can help to improve the quality of our air and water, protect wildlife, and prevent soil erosion.

What is soil?

Soil is a mixture of Minerals, organic matter, water, air, and living organisms. It is the foundation of life on Earth, providing nutrients and water for plants, and anchoring trees and other plants in place. Soil also helps to regulate the climate, filter water, and provide habitat for a wide variety of animals.

What is soil erosion?

Soil erosion is the process of soil being removed from the land by wind or water. It can be caused by natural forces, such as floods and storms, or by human activities, such as deforestation and agriculture. Soil erosion can lead to a loss of topsoil, which is the most fertile layer of soil. It can also damage Infrastructure-2/”>INFRASTRUCTURE, such as roads and buildings, and pollute waterways.

What are the causes of soil erosion?

There are many factors that can contribute to soil erosion, including:

Water: Rain and runoff can carry away soil particles, especially if the soil is loose or has been disturbed.
Wind: Wind can blow away loose soil particles, especially if the soil is dry.
Human activities: Human activities, such as deforestation, agriculture, and mining, can all contribute to soil erosion.
Climate Change: Climate change can lead to more extreme weather events, such as floods and droughts, which can increase soil erosion.

What are the effects of soil erosion?

Soil erosion can have a number of negative effects, including:

Loss of topsoil: Topsoil is the most fertile layer of soil, and it is essential for plant growth. When topsoil is eroded, it can take many years to replace.
Damage to infrastructure: Soil erosion can damage roads, buildings, and other infrastructure.
Pollution of waterways: Soil erosion can carry sediment and pollutants into waterways, which can harm fish and other aquatic life.
Loss of Biodiversity-2/”>Biodiversity: Soil erosion can lead to the loss of plant and animal species that depend on healthy soil.

What can be done to prevent soil erosion?

There are a number of things that can be done to prevent soil erosion, including:

Planting trees and other vegetation: Vegetation helps to hold soil in place and prevent it from being eroded.
Conserving water: Water conservation can help to reduce the amount of runoff, which can carry away soil particles.
Using cover crops: Cover crops are plants that are grown between rows of crops. They help to protect the soil from erosion and improve its fertility.
No-till farming: No-till farming is a method of farming that does not involve tilling the soil. This helps to keep the soil in place and prevent erosion.
Contour farming: Contour farming is a method of farming that involves planting crops in rows that follow the contours of the land. This helps to prevent water from running off the land and carrying away soil particles.
Terracing: Terracing is a method of farming that involves creating terraces on hillsides. This helps to slow down the flow of water and prevent erosion.
Stabilizing slopes: Slopes can be stabilized with rocks, logs, or other materials to prevent erosion.

What are the benefits of preventing soil erosion?

There are many benefits to preventing soil erosion, including:

Maintaining soil fertility: Soil erosion can lead to a loss of topsoil, which is the most fertile layer of soil. Preventing soil erosion helps to maintain soil fertility and ensure that there is enough land for food production.
Protecting infrastructure: Soil erosion can damage roads, buildings, and other infrastructure. Preventing soil erosion helps to protect these structures and save Money on repairs.
Reducing pollution: Soil erosion can carry sediment and pollutants into waterways, which can harm fish and other aquatic life. Preventing soil erosion helps to reduce pollution and protect the environment.
Maintaining biodiversity: Soil erosion can lead to the loss of plant and animal species that depend on healthy soil. Preventing soil erosion helps to maintain biodiversity and protect the natural world.

Soil is a mixture of four main components:
(a) Sand, silt, clay, and organic matter
(b) Sand, silt, clay, and water
(c) Sand, silt, clay, and air
(d) Sand, silt, clay, and nutrients
Soil is important because it:
(a) Provides a home for plants
(b) Filters water
(c) Stores carbon
(d) All of the above
Soil erosion is the process of soil being moved from one place to another by wind or water.
(a) True
(b) False
Soil conservation is the practice of protecting soil from erosion and other damage.
(a) True
(b) False
One way to conserve soil is to plant trees.
(a) True
(b) False
Another way to conserve soil is to practice no-till farming.
(a) True
(b) False
No-till farming is a method of farming that does not involve plowing the soil.
(a) True
(b) False
Plows can damage the Soil Structure and make it more susceptible to erosion.
(a) True
(b) False
Cover crops are plants that are grown between rows of other crops.
(a) True
(b) False
Cover crops help to protect the soil from erosion and improve its fertility.
(a) True
(b) False
Crop Rotation is a system of farming in which different crops are grown in the same field each year.
(a) True
(b) False
Crop rotation helps to prevent the build-up of pests and diseases in the soil.
(a) True
(b) False
Organic Farming is a method of farming that does not use synthetic pesticides or fertilizers.
(a) True
(b) False
Organic farming helps to protect the environment and improve the quality of food.
(a) True
(b) False
Soil is a non-renewable resource.
(a) True
(b) False
Soil can be replenished through natural processes such as weathering and erosion.
(a) True
(b) False
Soil can also be replenished through human activities such as composting and land reclamation.
(a) True
(b) False
Soil is a finite resource that needs to be protected.
(a) True
(b) False
We can all help to protect soil by making small changes in our daily lives.
(a) True
(b) False
Some ways to protect soil include:
(a) Reducing our use of pesticides and fertilizers
(b) Composting our food scraps
(c) Planting trees
(d) All of the above

Answers:
1. (a)
2. (d)
3. (a)
4. (a)
5. (a)
6. (a)
7. (a)
8. (a)
9. (a)
10. (a)
11. (a)
12. (a)
13. (a)
14. (a)
15. (b)
16. (a)
17. (a)
18. (a)
19. (a)
20. (d)