Structures for controlling soil erosion

Some structures for controlling erosion are:

1. Storm water diversion channel: This is the drain or direction, which diverts the storm water. It is the first line of defense and vital to the protection system for all lower structures.

2. Channel Terrace: To avoid soil dislodge and scouring action, some form of earthwork at right angles to the steepest slope is used to interrupt the surface run-off. These works are known as terraces or ridge or bund. In the cross-section the features common to all are an excavated channel, hence the name channel terrace.

3. Artificial watercourse: For discouraging the water from channels, frequent natural watercourse is not available. So it must be artificially made. They will normally run straight the steepest slope and have a bank on each side to contain the water.

4. Bench terrace: Bench terracing is converting a steep slope into a series of steps. They may be constructed on the contour, to minimize run-off. When regular cultivation is not required, as far tree crops, smaller terraces are effective.

5. Irrigation terrace: When flat bench terrace has a raised lip at the outer edge to retain irrigation water, this type of terrace is known as irrigation terrace.

6. Orchard terrace: For too sloppy areas and where soil is too shallow then the land may be developed for tree crops by the use of intermittent terraces, called orchard terraces.

7. Contour bund: In fact it is a rudimentary type of channel terrace. Somewhere, it is taken as erosion-controlling bank, which have grasses or shrubs, planted on them.

8.  Pasture furrow: It is small shallow drain whose function is to spread out surface water and allow it to concentrate in minor watercourse. Primary purpose is to conserve water by increasing infiltration and the technique is frequently used on grassland hence the name pasture furrows.

9.Tied ridging: It consists of covering the whole surface with closely spaced ridges in two directions at right angle so the ground is formed into a series of rectangular depressions.

10. Contour cultivation or grass strips: On gentle slopes, it may be sufficient to slow down surface run off by carrying out all tillage operations on the contour.

11.Ridge and furrow: This combines an element of erosion control with surface drainage. This is useful for gentle slopes and large areas .The ground is tilted into wide parallel ridges of the order of 10m wide with intervening furrows about 1/2m deep.

12. Check dams: The structure constructed to control the velocity of running water along the gullies is called check dams. They reduce the steep gradient of gully into a series of steps with low rises and long flat treads, reducing the velocity of running water. This makes water to deposit and increase the percolation of water on a soil.

  Print