Soil reclamation -(Land reclamation)

Soil-reclamation/”>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 degraded land to a condition that is suitable for agricultural or other purposes. It can be used to restore land that has been damaged by mining, deforestation, or other human activities.

There are a number of different methods that can be used for soil reclamation, depending on the specific type of damage that has occurred. Some common methods include:

Revegetation: This involves planting new Plants on the land. The plants help to improve the Soil Structure and fertility, and they also help to prevent erosion.
Amendments: This involves adding materials such as compost or manure to the soil. These materials help to improve the soil structure and fertility.
Drainage: This involves installing Drainage Systems to remove excess water from the soil. This helps to prevent waterlogging and soil erosion.
Terracing: This involves creating terraces on the land. This helps to reduce soil erosion and improve water drainage.
Contour farming: This involves planting crops in rows that follow the contours of the land. This helps to reduce soil erosion and improve water drainage.

Soil reclamation can be a complex and time-consuming process, but it can be very effective in restoring degraded land to a condition that is suitable for agricultural or other purposes.

Here are some subtopics on soil reclamation:

Types of Soil reclamation: There are a number of different types of soil reclamation, depending on the specific type of damage that has occurred. Some common types of soil reclamation include:
- Mining reclamation: This involves restoring land that has been damaged by mining.
- Deforestation reclamation: This involves restoring land that has been damaged by deforestation.
- Industrial reclamation: This involves restoring land that has been damaged by industrial activities.
- Agricultural reclamation: This involves restoring land that has been damaged by agricultural activities.
Methods of soil reclamation: There are a number of different methods that can be used for soil reclamation, depending on the specific type of damage that has occurred. Some common methods of soil reclamation include:
- Revegetation: This involves planting new plants on the land. The plants help to improve the soil structure and fertility, and they also help to prevent erosion.
- Amendments: This involves adding materials such as compost or manure to the soil. These materials help to improve the soil structure and fertility.
- Drainage: This involves installing drainage systems to remove excess water from the soil. This helps to prevent waterlogging and soil erosion.
- Terracing: This involves creating terraces on the land. This helps to reduce soil erosion and improve water drainage.
- Contour farming: This involves planting crops in rows that follow the contours of the land. This helps to reduce soil erosion and improve water drainage.
Benefits of soil reclamation: Soil reclamation can provide a number of benefits, including:
- Improved soil quality: Soil reclamation can help to improve the soil quality by increasing the organic matter content, improving the drainage, and reducing the erosion.
- Increased crop yields: Soil reclamation can help to increase crop yields by providing a more suitable environment for plant Growth.
- Reduced soil erosion: Soil reclamation can help to reduce soil erosion by providing a more stable surface and by improving the drainage.
- Improved water quality: Soil reclamation can help to improve water quality by reducing the runoff of pollutants into waterways.
- Increased Biodiversity-2/”>Biodiversity: Soil reclamation can help to increase biodiversity by providing a more suitable habitat for plants and animals.
Challenges of soil reclamation: Soil reclamation can be a complex and time-consuming process, and it can be expensive. There are a number of challenges that can be associated with soil reclamation, including:
- The type of damage that has occurred: The type of damage that has occurred will determine the type of soil reclamation that is needed.
- The Climate: The climate can affect the success of soil reclamation. For example, in dry climates, it may be difficult to establish plants.
- The topography: The topography of the land can affect the success of soil reclamation. For example, it may be difficult to terrace steep slopes.
- The availability of Resources: The availability of resources, such as water, labor, and materials, can affect the success of soil reclamation.
- The social and political context: The social and political context can affect the success of soil reclamation. For example, there may be opposition to soil reclamation from local residents.
Conclusion: Soil reclamation is a complex and time-consuming process, but it can be very effective in restoring degraded land to a condition that is suitable for agricultural or other purposes. There are a number of different types of soil reclamation, and the best type of soil reclamation will depend on the specific type of damage that has occurred.

What is land reclamation?

Land reclamation is the process of converting wasteland or derelict land into a more productive state. It can be used to restore land that has been damaged by human activity, such as mining or industrial pollution, or to create new land for development.

What are the benefits of land reclamation?

There are many benefits to land reclamation, including:

Increased land for development: Land reclamation can be used to create new land for housing, businesses, or other development. This can help to meet the growing demand for land in urban areas.
Improved water quality: Land reclamation can help to improve water quality by reducing pollution and sedimentation. This can benefit both human Health and the environment.
Increased biodiversity: Land reclamation can create new habitats for plants and animals. This can help to protect biodiversity and improve the environment.
Reduced greenhouse gas emissions: Land reclamation can help to reduce greenhouse gas emissions by sequestering carbon dioxide. This can help to mitigate Climate Change.

What are the challenges of land reclamation?

There are also some challenges associated with land reclamation, including:

Cost: Land reclamation can be a costly process, depending on the type of land being reclaimed and the extent of the damage.
Time: Land reclamation can take a long time, depending on the type of land being reclaimed and the extent of the damage.
Environmental impact: Land reclamation can have an environmental impact, depending on the methods used. For example, some methods may involve the use of chemicals or heavy machinery, which can pollute the environment.

What are some examples of land reclamation?

Some examples of land reclamation include:

The construction of polders: Polders are artificial islands that are created by enclosing an area of land with dikes. They are often used in coastal areas to protect land from flooding.
The creation of artificial wetlands: Artificial wetlands are created by flooding an area of land with water. They can be used to improve water quality and provide habitat for wildlife.
The restoration of mine sites: Mine sites can be restored by backfilling the mine shafts and covering the area with topsoil. This can help to create new land for development or to restore the land to its natural state.

What are the future trends in land reclamation?

The future trends in land reclamation are likely to focus on the following:

The use of more sustainable methods: Land reclamation methods are becoming more sustainable, with a focus on using less energy and fewer resources.
The use of new technologies: New technologies are being developed to help with land reclamation, such as 3D printing and drones.
The involvement of the public: The public is becoming more involved in land reclamation, with a focus on community-led projects.

Soil reclamation is the process of restoring land that has been damaged by human activity or natural disasters.
Soil reclamation can be done through a variety of methods, including:
- Terracing: This involves creating a series of terraces on a slope to reduce erosion.
- Contour farming: This involves planting crops in rows that follow the contours of the land to reduce erosion.
- Cover Cropping: This involves planting cover crops, such as Grasses or legumes, between rows of crops to help prevent erosion and improve Soil fertility.
- No-till farming: This involves planting crops without disturbing the soil, which helps to reduce erosion and improve soil health.
- Conservation Tillage: This involves using methods such as minimum tillage or no-till farming to reduce soil disturbance.
Soil reclamation is important because it helps to protect the environment and improve the Quality Of Life for people.
Soil reclamation can help to reduce erosion, which can lead to flooding and sedimentation.
Soil reclamation can also help to improve soil fertility, which can lead to increased crop yields.
Soil reclamation can also help to improve water quality, which can lead to a healthier environment for people and wildlife.
Soil reclamation can be a complex and expensive process, but it is an important Investment in the future of our planet.

Here are some multiple choice questions about soil reclamation:

Soil reclamation is the process of:
- Restoring land that has been damaged by human activity or natural disasters.
- Removing pollutants from soil.
- Improving the quality of soil.
- All of the above.
Soil reclamation can be done through a variety of methods, including:
- Terracing.
- Contour farming.
- Cover cropping.
- No-till farming.
- All of the above.
Soil reclamation is important because it helps to:
- Protect the environment.
- Improve the quality of life for people.
- Reduce erosion.
- Improve soil fertility.
- All of the above.
Soil reclamation can be a complex and expensive process, but it is an important investment in the future of our planet.
- True.
- False.

Answers:
1. (d)
2. (d)
3. (d)
4. (t)