By : Neha Dhyani
Updated : Apr 4, 2022, 10:48
Drainage is a well-defined channel constructed to direct the flow of water. A network of these channels is called a drainage system. A Drainage Pattern is created over time by stream erosion, revealing characteristics of the region for example, the type of rocks or geological structures in the landscape. The pattern is formed by lakes, streams, and rivers in a specific drainage basin.
A myriad of factors governs the Drainage Pattern. Some of them are geological structure, the topography of the land, velocity of water, volume of water, etc. Drainage channels are easier to develop on surfaces that are least resistant to erosion and have an enhanced runoff.
Types of Drainage Pattern
Primarily, there are eight types of Drainage Patterns. They are:
- The channels look similar to garden trellis
- It develops in areas where the sedimentary rocks have been tilted or folded and then eroded.
- For example, the Appalachian Mountains of North America.
- It develops in areas that have elongated, similar landforms, similar to outcropping-resistant rock bands.
- The pattern is caused due to steep slopes with a certain degree of relief. The steep slopes make the streams straight and swift, with minimal tributaries.
- It is perhaps the most well-known Drainage Pattern. The pattern resembles the branching of tree roots.
- Only develops in regions underlain by homogenous material, which means the geology beneath the stream has no specific structure and is weathering resistant. There is no control over the direction of erosion.
- They are found in areas that have undergone faulting. The surface has minimal topography and a combination of bedding planes, faults, or fractures that forms a rectangular pattern.
- Streams follow the least resistant path, making it prominent in locations where the surface rocks are weak.
- They are formed from the disruption of a prior Drainage Pattern. For instance, a dendritic pattern can be disrupted due to any external reasons, leading to the formation of a deranged pattern.
- Example- Canadian shield
- It forms around a central elevated location. The pattern appears similar to Volcanoes.
- Laccoliths and domes are geological structures that exhibit perfect radial Drainage Patterns.
- They are developed in reassigns where faults and bedrocks joints intersect at an extremely acute angle.
- The angles are comparatively more acute than rectangular Drainage Patterns.
- This pattern is the opposite of the radial Drainage Pattern. It flows towards a central depression.
- It is prominent in southwestern and western areas of the United States as the basins show internal drainage systems.
The Drainage Patterns are categorized based on texture and form. Geologists, hydrologists, and other professionals take a deep interest in studying these patterns as it gives us vital information about the land.
FAQs on Drainage Pattern
Q.1. Does the number of drainage channels affect the Drainage Pattern?
Ans. Sloppy surfaces usually create fewer drainage channels, resulting in a coarser Drainage Pattern.
Q.2. What are the 4 types of Drainage Patterns?
Ans. The Types of Drainage Patterns are dendritic, trellis, rectangular, and radial patterns.
Q.3. Give examples of Dendritic Drainage Pattern
Ans. Some examples include parts of British Columbia, Indus, and Ganga.
Q.4. What type of Drainage Pattern is found in the Western Ghats of India?
Ans. A parallel Drainage Pattern is found in the Western Ghats of India.