DRAINAGE PATTERNS .
- 2. TOPICS TO BE COVERED Introduction Types of Drainage Pattern : 1. Trellised Drainage pattern 2. Dendritic Drainage pattern 3. Rectangular Drainage pattern 4. Radial Drainage pattern 5. Centripetal Drainage pattern 6. Annular drainage pattern 7. Barbed drainage pattern 8. Pinnate drainage pattern 9. Herringbone Drainage Pattern 10.Parallel Drainage pattern
- 3. INTRODUCTION Drainage patterns refer to the shapes and arrangements of river systems in a specific area. The location, number and flow directions of different streams of a particular region depend on: 1.Nature of slope : The steepness and direction of the terrain affect water flow and river formation. 2.Structural Control: Features like faults, folds, and fractures in the earth's crust guide water flow. 3.Lithological Characteristics: The type of rocks (hard or soft) influences erosion, shaping the drainage pattern. 4.Tectonic Factors: Movements of the earth's crust, such as uplift or subsidence, shape the landscape and drainage patterns. 5.Climatic Conditions: Climate affects water availability (rainfall, snowmelt) and river flow. 6.Vegetal Characteristics: The type and density of vegetation impact soil erosion and water flow.
- 4. TYPES OF DRAINAGE PATTERNS 1. Trellised Drainage Pattern A trellised drainage pattern is a type of river and stream network that looks like a garden trellis. Trellised drainage patterns form in regions with simple folds in the Earth's crust with alternating parallel ridges (anticlines) and parallel valleys (synclines). The landscape typically has layers of hard and soft rocks. The hard rocks form ridges, while the softer rocks erode away, creating valleys. This difference in rock type and erosion is key to forming the pattern. Master consequent streams (main rivers) flow along the synclinal valleys, following the natural slope of the land. These valleys are often long and narrow, running parallel to each other. Lateral consequent streams (tributaries) form on the sides of the ridges. These streams flow down the slopes and join the main rivers in the valleys at almost right angles. Because they are influenced by the slope and rock structure, they have straight courses.
- 5. TYPES OF DRAINAGE PATTERNS
- 6. TYPES OF DRAINAGE PATTERNS Example : Appalachian Mountains, USA: The Appalachian Mountains have a classic trellised drainage pattern, with main rivers flowing through valleys and tributaries joining at right angles.
- 7. TYPES OF DRAINAGE PATTERNS 2. Dendritic Drainage Pattern The drainage pattern resembling the branches of a tree is known as dendritic pattern It forms in areas where the rocks are of the same type i.e. of homogeneous lithologies and the ground is relatively flat or gently sloping . This type of pattern can be found in various places, such as mountains, plateaus, plains, deserts, and areas that were once covered by glaciers. Formation : A main stream (trunk stream) forms first on a gently sloping surface. Tributaries, which are smaller streams, develop on both sides of this main stream. Over time, these tributaries create a network that looks like tree branches.
- 8. TYPES OF DRAINAGE PATTERNS Stages of development : Over time, more tributaries form, making the pattern denser and "closed." In the beginning, the pattern is "open," with few, widely spaced streams. At much later stage i.e. in the penultimate stage of drainage development , some streams merge due to river capture, and the pattern become simplified Note : If the land is flat with gentle slopes and the rocks are impermeable, the pattern spreads out widely. If the land has steeper slopes, the pattern stretches more in length than in width.
- 9. TYPES OF DRAINAGE PATTERNS Example : rivers of the northern plains
- 10. TYPES OF DRAINAGE PATTERNS 3. Rectangular Drainage Pattern A rectangular drainage pattern is a type of river system where streams and rivers form a grid-like pattern, making right-angle turns. This pattern shares similarities with the trellised drainage pattern, but there are key differences: 1.Right-Angle Confluences: In both rectangular and trellised patterns, tributary streams join the main rivers at almost right angles. However, in the rectangular pattern, these angles are influenced by the lines of weakness in the rock, such as faults, fractures, and joints. 2. Stream Spacing: Rectangular Pattern: The streams are widely spaced. This means there is more distance between the tributaries. Trellised Pattern: The tributaries are more closely spaced, forming a denser network.
- 11. TYPES OF DRAINAGE PATTERNS Example : In the Vindhya and Satpura regions, the Narmada River and its tributaries, are more commonly associated with a rectangular drainage pattern.
- 12. TYPES OF DRAINAGE PATTERNS 4. Radial Drainage Pattern Radial drainage pattern also known as centrifugal pattern is a drainage pattern where water flows outward from a central high point in all direction It is obvious that dome structures, volcanic cones, batholiths and laccoliths, residual hills, small tablelands, mesas and buttes, and isolated uplands favour the development of ideal radial pattern.
- 13. TYPES OF DRAINAGE PATTERNS Example River originating from the Amarkantak range
- 14. TYPES OF DRAINAGE PATTERNS 5. Centripetal Drainage Pattern A centripetal drainage pattern is the opposite of a radial drainage pattern. In this pattern, streams and rivers flow inward from different directions and converge at a central point, which is usually a low-lying area like a depression, basin, or crater.
- 15. TYPES OF DRAINAGE PATTERNS Example : Kathmandu Valley, Nepal: In this area, streams flow towards the centre of a tectonically formed circular basin, creating a centripetal drainage pattern.
- 16. TYPES OF DRAINAGE PATTERNS 6. Annular Drainage Pattern An annular drainage pattern looks like circular rings of streams around a high central area. It forms where a dome mountain with alternating hard and soft rock layers gets eroded, leading to a ringed pattern of rivers and streams. Hard rocks resist erosion better, so they form outer rings. Soft rocks erode more quickly, creating circular depressions or clefts. Streams start at the top of the dome and flow downwards in all directions (like radial pattern). The tributaries, however, flow along the circular clefts in the softer rock, giving the pattern its ring-like appearance. Over time, additional tributaries can develop, joining the main streams and creating a complex pattern that might look similar to a trellised pattern. Example : Weald, England: The Weald area has an annular drainage pattern formed over ancient, eroded domes.
- 17. TYPES OF DRAINAGE PATTERNS 7. Barbed Drainage Pattern Barbed drainage pattern, a rare kind of drainage pattern, is formed when the tributaries flow in opposite direction to their master streams. The tributaries join their master streams in a hook-shaped bend. Such pattern is generally developed due to river capture . River capture happens when a river or stream from one area captures or diverts the flow of another river, leading to the tributaries flowing into the main river in the opposite direction.
- 18. TYPES OF DRAINAGE PATTERNS 8. Pinnate Drainage Pattern A Pinnate pattern is developed in a narrow valley flanked by steep ranges. The tributaries originating from the steep sides of parallel ridges join the longtitudinal master consequent occupying the valley at acute angles(less than 90 degrees) meaning they enter the main river at a sharp, narrow angle It looks like the veins of a leaf.
- 19. TYPES OF DRAINAGE PATTERNS Example - Upper Son river
- 20. TYPES OF DRAINAGE PATTERNS 9. Herringbone Drainage Pattern The herringbone drainage pattern also known as rib pattern is a specific arrangement of rivers and streams that looks like the bones of a fish or like the rib bones of human beings. Here's how it forms and what it looks like: This pattern develops in mountainous regions where there are broad valleys surrounded by parallel ridges with steep slopes. The main rivers, known as longitudinal consequent streams, flow along the valleys between the ridges. Smaller streams, or tributaries, flow down from the steep ridges into the main rivers. These tributaries join the main rivers at almost right angles. The pattern resembles the rib bones of a fish or the spine of a herring fish, where the main river is like the spine and the tributaries are like the ribs extending from it.
- 21. TYPES OF DRAINAGE PATTERNS Example – Upper Jhelum River, Kashmir: This river receives many tributaries from both sides, creating a herringbone pattern.
- 22. TYPES OF DRAINAGE PATTERNS 10. Parallel Drainage Pattern A parallel drainage pattern is where streams and rivers run roughly parallel to each other, like lines running side by side. Here’s how it forms and what it looks like: In this pattern, the rivers and streams flow in parallel lines, all going in the same general direction. This pattern typically forms in areas with steep, uniform slopes. The streams follow the slope of the land, so they run parallel to each other. The streams start at higher elevations and flow down the slope. Because the slope is uniform, the streams stay roughly parallel as they move. The pattern looks like a series of parallel lines on the landscape, similar to stripes on a road.
- 23. TYPES OF DRAINAGE PATTERNS Examples: Western Coastal Plains of India: Streams originating from the Western Ghats flow westward in parallel courses towards the Arabian Sea. .
- 24. MULTIPLE CHOICE QUESTIONS 1. Which drainage pattern resembles the branches of a tree ? A. Trellised B. Dendritic C. Radial D. Rectangular 2. In which drainage pattern do the streams converge towards a central point? A. Dendritic B. Trellised C. Radial D. Centripetal 3. What characterizes a trellised drainage pattern? A. Streams run parallel to one another B. Streams flow into a central basin C. Streams intersect at right angles D. Streams resemble the branches of a tree 4. Which drainage pattern is typical in areas with a uniform structure and gentle slopes? A. Parallel B. Rectangular C. Annular D. Dendritic Answer given at the end i.e.28 page
- 25. MULTIPLE CHOICE QUESTIONS 5. The radial drainage pattern is commonly found around which geographical feature? A. Plateau B. Fold mountains C. Dome or volcanic cones D. Coastal plains 6. Which drainage pattern forms where resistant and less resistant rock layers create alternating ridges and valleys? A. Annular B. Trellised C. Radial D. Parallel 7. What is the main feature of an annular drainage pattern? A. Streams form a ring-like pattern around a central highland B. Streams converge towards a central point C. Streams follow a rectangular grid pattern D. Streams radiate outward from a central point
- 26. MULTIPLE CHOICE QUESTIONS 8. In which pattern do streams flow parallel to each other, usually due to steep slopes? A. Dendritic B. Radial C. Parallel D. Rectangular 9. Which drainage pattern is characterized by network of streams that appear to be spine of a herring fish ? A. Annular B. Trellised C. Radial D. Herringbone 10. Barbed drainage pattern is characterized by: A. Streams flowing in opposite directions to the main river B. Streams converge towards a central point C. Streams follow a rectangular grid pattern D. Streams radiate outward from a central point
- 27. MULTIPLE CHOICE QUESTIONS 11. In which drainage pattern do rivers and streams follow fault lines or fractures? A. Dendritic B. Radial C. Parallel D. Rectangular 12. In which drainage pattern do streams flow away from a central high point? A. Annular B. Trellised C. Radial D. Herringbone 13. The barbed drainage pattern is typically formed due to: A. River capture B. Volcanic activity C. Glacial activity D. Erosion of a circular mountain range 14. The pinnate drainage pattern resembles: A. The veins of a leaf B. A star C. A circular ring D. A ladder
- 28. MULTIPLE CHOICE QUESTIONS 15. Herringbone drainage pattern typically occurs in: A. Coastal regions B. Faulted regions C. Folded mountain regions D. Areas with parallel ridges and valleys 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 B D C D C B A C D A D C A A D Answers :