An Introduction to Drainage Systems
Drainage systems are in place to remove waste water or extra water. If we do not have a proper drainage system, it may lead to floods in the low-lying areas and hence causing damage to property and health. An improper drainage system may also cause various kinds of disease and act as a breeding ground for various insects.
What are Drainage Systems?
Drainage is defined as the natural or artificial method to remove excess water/wastewater from one place to another place through channels.
Residential Drainage System
A residential drainage system removes extra water from the residential area. This system helps whisk water away from roofs, driveways, roadways, and homes.
Types of Drainage Systems
There are mainly four types of drainage systems:
Surface Drainage System
Subsurface Drainage System
Slope Drainage System
Downspout and Gutter System
Surface Drainage System
For the surface drainage system, it is needed to dig a few ditches which are used as a funnel for excess water. With this, we can send water away from home or any area to prevent flooding.
This type of drainage system is mostly found on very flat land. It is done to prevent rainwater accumulation on a flat surface because the accumulation of rainwater on a flat surface can lead to damage to our homes.
Subsurface Drainage System
For the subsurface drainage system, we use a drain or a pipe that goes deep inside the soil. Here, we can also use a sump pump to push water through these pipes as well. These drainage systems are made to remove excess water from the soil. Plants can grow properly with this drainage system because excess water that is trapped in roots or plants can cause them to rot.
Slope Drainage System
In this drainage system, pipes are installed on an inclined surface. This makes water move naturally away from the home or any area. Pipes can be made of steel, concrete, or plastic and wrapped with a protective layer.
Downspout and Gutter System
In this drainage system, the downspout is connected to the gutter, which gets rid of excess water that builds on the roof. It is the most essential drainage system used at home. Without this system, rainwater comes off the roof and damages our house.
Open Drainage
The open drainage system utilises tail, open side ditches, and lateral and outfall ditches. The open drainage system is mostly used to collect wastewater that is not sewage. These types of drainage systems are used to dispose of sanitary waste that is highly unhygienic and unsafe.
The open drainage system is not safe to use because people can easily come in contact with this and it may cause various types of disease in people. The benefit of this type of drainage system is it is convenient to build and maintain.
Closed Drainage System
This type of drainage system forms a closed underground network. In this type of drainage system, first refuse is collected from individual areas and then transported to the main network at last goes to the treatment plant.
A closed drainage system prevents human contact with waste and wastewater. It also prevents the spreading of disease. And also does not act as a breeding ground for insects. Cleaning a closed drainage system is easier than an open drainage system.
Conclusion
The drainage system is the system used to remove waste or extra water. There are four types of drainage systems. The open and closed drainage system is also there. Closed drainage systems are better than open drainage systems. Drain systems are an important necessity in human civilization to maintain hygienic conditions.
FAQs on Drainage Systems
1. What is a drainage system as per the CBSE Class 9 syllabus?
In geography, a drainage system refers to the network of rivers, streams, and other water channels that drain surface water from a specific area, known as a drainage basin. It describes the origin and development of streams through time and how they relate to the region's geology and topography. These systems are crucial for shaping landscapes and supporting ecosystems.
2. What are the four main types of drainage patterns?
Drainage patterns are determined by the topography and geology of the land. The four primary patterns studied in the NCERT syllabus are:
- Dendritic Pattern: This tree-branch-like pattern develops where the river channel follows the slope of the terrain. It is common in areas with uniform rock structure.
- Trellis Pattern: In this pattern, primary tributary rivers flow parallel to each other, and secondary tributaries join them at right angles. It forms in regions of folded topography with alternating hard and soft rocks.
- Rectangular Pattern: This pattern develops on a strongly jointed rocky terrain, where streams follow the path of least resistance and are concentrated in places where the rock is weakest.
- Radial Pattern: This pattern develops when streams flow in different directions from a central peak or dome-like structure, such as a volcano.
3. What is the difference between a drainage basin and a watershed?
While often used interchangeably, there is a technical difference. A drainage basin is an area of land drained by a major river and its tributaries. A watershed is the boundary or dividing line (usually a ridge or high ground) that separates one drainage basin from another. However, in common usage, 'watershed' can also refer to the entire area of a smaller drainage basin.
4. How does the geology of a region influence its drainage pattern?
The underlying rock structure (geology) is a primary factor in determining a drainage pattern. For example, in an area with uniform, flat-lying rock, a dendritic pattern will likely form as water flows evenly across the surface. In contrast, an area with folded layers of alternating hard and soft rock will force rivers into parallel valleys, creating a trellis pattern. The presence of faults and joints in hard rock leads to a rectangular pattern.
5. What are the key features of the Himalayan and Peninsular river systems in India?
The major drainage systems of India are broadly divided into two groups:
- The Himalayan Rivers: These rivers are perennial, meaning they have water throughout the year as they are fed by both rainfall and melting snow from the Himalayas. Major examples include the Indus, Ganga, and Brahmaputra systems. They have long courses and form large basins.
- The Peninsular Rivers: These rivers are mostly seasonal or non-perennial, as their flow depends on rainfall. They have shorter and shallower courses compared to the Himalayan rivers. Major examples include the Mahanadi, Godavari, Krishna, and Kaveri.
6. What is the difference between an open and a closed drainage system in residential areas?
An open drainage system consists of exposed ditches and channels to carry away wastewater and stormwater. While easy to build, it can be unhygienic and a breeding ground for pests. A closed drainage system uses a network of underground pipes to transport wastewater to a treatment facility. This system is far more hygienic, prevents direct contact with waste, and is the standard for modern urban planning.
7. Why is a proper drainage system important for a house or building?
A proper drainage system is essential to protect a building's structure and ensure a healthy living environment. It serves several key functions, such as preventing waterlogging around the foundation, which can cause structural damage. It also safely removes wastewater to prevent the spread of diseases and redirects rainwater from roofs and surfaces to avoid flooding and property damage.
8. What is a 'river regime' and what factors control it?
A river regime refers to the annual pattern of variation in a river's flow or discharge. It shows how the volume of water in the river changes from season to season. The primary factors that control a river's regime are:
- The amount and pattern of rainfall in its catchment area.
- The rate of snowmelt, especially for Himalayan rivers.
- The underlying geological structure, which affects groundwater contribution.
- Human activities such as the construction of dams and irrigation canals.
9. What are the main types of man-made drainage systems used for managing water?
Beyond natural river systems, several man-made systems are used to manage water, particularly in residential and agricultural areas. The main types include:
- Surface Drainage: Uses open ditches and channels to remove excess water from the land's surface.
- Subsurface Drainage: Employs underground perforated pipes (also called French drains) to remove excess water from the soil root zone.
- Slope Drainage: Uses pipes on inclined surfaces to move water away from structures like homes and roads.
- Downspout and Gutter Systems: Collects rainwater from rooftops and directs it away from a building's foundation.
10. What is a 'water divide' with an example from India?
A water divide is any elevated area, such as a mountain or an upland, that separates two drainage basins. It acts as a boundary, directing surface runoff into different river systems. A prominent example in India is the city of Ambala, which is located on the water divide between the Indus and the Ganga river systems. Rivers to the west of Ambala flow into the Indus system, while those to the east become part of the Ganga system.
