Dendritic patterns, which are by far the most common, develop in areas where the rock (or unconsolidated material) beneath the stream has no particular fabric or structure and can be eroded equally easily in all directions. Examples would be granite, gneiss, volcanic rock, and sedimentary rock that has not been folded.

Dendritic drainage patterns look like tree branches with lots of twigs. They form in areas with flat and uniform bedrock like sandstone or shale. Can you find these patterns on a map? Radial drainage patterns form when streams and rivers flow off a central peak or dome like a volcano .

Dendritic patterns, which are by far the most common, develop in areas where the rock (or unconsolidated material) beneath the stream does not have structures that control the stream flow patterns such as folds and joints; the materials can be eroded by the stream equally easily in all directions.

Dendritic drainage pattern developed on flat-lying limestone in central Yemen.

Dendritic or Pinnate Drainage Pattern This is an irregular tree branch shaped pattern that develops in a terrain which has uniform lithology (uniform rock structure), and where faulting and jointing are insignificant. Examples: Indus, Godavari, Mahanadi, Cauvery, Krishna.

dendritic drainage pattern

There are 4 main types of subsurface drainage systems:

• corrugated and PVC slotted subsurface pipes.
• mole drainage (including mole drains, mole drains over collector pipe systems and gravel mole drains)
• interceptor drains.
• ground water pumps.

There are two types of artificial drainage: surface drainage and subsurface drainage.

The primary purpose of a road drainage system is to remove the water from the road and its surroundings. The road drainage system consists of two parts: dewatering and drainage. “Runoff” covers the water flowing from the surface of the pavement via road shoulders and inner slopes to the ditches.

All above ground and below ground horizontal drainage pipes should be laid to an adequate gradient. Gradients from 1 in 40 to 1 in 110 will normally give adequate flow velocities. A gradient of 1 in 80 is suitable for commencing calculations for pipe schemes.

In order to carry the flow and to avoid blockages, the drain or sewer that you intend to connect to generally needs to be at least 0.8m lower than the ground floor level. If it is less than this, you should seek advice from a builder, architect or drainage engineer.

Proper slope of gravity drainage and sewer pipes is important so that liquids flow smoothly, which helps transport solids away without clogging. A pipe that is too flat will prevent waste from flowing away.

1 in 80 = 12mm per metre. 3200 x 0.012 = 40mm. 1 in 40 = 25mm per metre. 3200 x 0.025 = 80mm.

A 1:100 slope means that for every 100 metres along the ground, the slope height increases by 1 metre. A 1:0.5 slope means that for every 1 metre along the ground, the slope height increases by 0.5 metres.

A road sign indicating a 6% grade, or 6% slope. A six percent slope means that the road elevation changes 6 feet for every 100 feet of horizontal distance (Figure 1.3). A road climbs at a gradient of 6 percent. The road gains 6 feet in elevation for every 100 feet of horizontal distance.

Converting from Percent Grade to Degrees Moving from geometry from trigonometry, the slope is also the same as the tangent of the angle of elevation. 176, which yields a percent grade of 17.6. Therefore, a 10-degree incline is slightly higher than you are likely to experience on a standard treadmill.