6. PRINCIPLE
●Plants and trees are surrounded by stones or ridges
that collect rainwater and surface run-off
●Collecting run-off by constructing basins to prevent
water run off to allow it to infiltrate into soil profile
and use it for further use like irrigation while
enhancing soil contents and increasing ground water
table by creating low soil ridges or optional stone
walls
7.
8. MAIN CHARACTERISTICS
● Over land flow harvested from short catchment
length
●Catchment length usually is between 1 and 30 m
●Runoff water is stored in soil profile
●Ratio catchment:cultivated area usually lies
between 1:1 to 3:1
9. ●Plant growth observed is even
●Works well on gentle slope ideally less than 5%
●A steeper slope only in case of very small
catchment basin
●Normally no provision for overflow is provided
●plant/crop growth in unfavourable condition is
possible
10. TYPES OF MICRO-CATCHMENT
●Negarim/ v-shaped micro-catchment (for trees)
●Contour bunds (for tree)
●Contour ridges (for crops)
●Semi-circular bunds(for ranges and fodder)
●Run off basins
11. NEGARIM
●Also known as v shaped micro-catchment
●Short slope catchment for trees and grass
●V shape is formed by small ridges with infiltration
pits
●Rainfall can be as low as 150mm per annum
●Depth of soil should be at least 1.5-2m for proper
infiltration
●Each micro catchment consists of catchment area and
infiltration pits
12.
13. LIMITATIONS
●Not easily mechanised once the tree is planted it is not
possible to operate and cultivate with machines trough
the tree lines. Cost increases as the size of micro
catchment increases
14. CONTOUR BUND
●This is used to grow trees and grass over contours
●Each bunds on contour spaced at 5-10m apart with
furrow up-slope and cross ties
●Is mechanised method can be used to plant over
large catchment area
●A minimum of 200mm of rainfall is required in semi
arid regions and more in arid regions
●Common size of catchment is 10-50 meter-sq
15. LIMITATION
●Not suitable for eroded land forms
●Sustainability is an issue with high cost of
maintenance for repair of bunds
16. CONTOUR RIDGES
●Also known as micro-water shed, used for growing
crops
●Small earth ridges on contour at an interval of 1.5 to
5m apart are constructed with up slope furrow and
cross ties and uncultivated catchment between ridges
●For production of crops with fertile soil usually in
semi arid regions
●Annual rainfall should be between 300-700mm
●Catchment:cultivated area ratio is usually 2:1
17. LIMITATIONS
Bunds are required to be repaired every season contour
ridges are limited to area with high rainfall and
cultivated area is small leading to small harvest
18. SEMI CIRCULAR BUNDS
●These are earth embankments in the shape semicircle
with the tip of bund on semicircle
●These are used for growing fodder, shrubs and in some
cases trees
●About 200-750mm rainfall is required and slopes below
2% is preferred
●Bunds can either be made narrow and closely spaced or
large and wider spaced
●Radii of bunds varies from 6-20m with C:CA 3:1
21. ADVANTAGES
●A Micro-catchment system has many advantages over other water
harvesting and irrigation systems
● Micro catchments are simple and inexpensive to construct
●Soil fertility is increased by trapping organic matter in the soil due to
surface run-off
●Many number of crops and plants can be grown simultaneously
●Maintenance cost is very low
●Most effective method of water harvesting in arid regions
●Increased crop yield and provide erosion control functions
22. LIMITATION
●Requires deep soil profile at least 2 metre deep
●Bunds need to be repaired constantly due bund
breaking
●Applicable at only small scale since implementation
process is not easily mechanised
●unsustainably due to various reasons and lack of
knowledge is a big issue
●Cost of construction and maintenance increases as
the catchment size increases
