Management of dry lands UE Past Papers Questions.

A large part of the drylands suffers from erosion due to water because rainfall usually comes in few, intensive storms. Give a detailed account of the rainfall erosivity factor, including the sub-factors that aggravate it, and how the factor may be controlled.

Answer / Solution

UNSOLVED

Clearly differentiate the following terms:

1. Winter -from continental-rainfall pattern
2. Climate change from global warming
3. Ephemeral annual from succulent perennial plants
4. Bench terracing from progressive bench terrace formation
5. Runoff-from flood flow-water harvesting
6. Agents from factors of erosion
7. Soil erosion from soil loss
8. Detachment limited – from transport limited-soil loss
9. Pipe-from tunnel-erosion
10. Unit plot from runoff plot

Answer / Solution

UNSOLVED

In order to curb soil and water loss, a farmer has decided to alternate strips of maize (Zea mays L.) and bambarranuts (Voandzea subterranea L.) that reduces soil loss by a third . The farmer will plant these two crops along the contour, thus minimising soil loss to a quarter. If the field is 50 m by 221 m on a gradient of 18%, the rainfall erosivity index in that area is 500 Jha^-1 and the soil`s resistance to erosion is 5, calculate the annual soil loss from this field.

Useful formulae/information:

1. A=R x K x LS x C x P
2. LS=(l/22.1 m)^m x (0.065 +0.045s +0.0065s^s)
3. V=A x R x Ro
4. One bucket has a volume of 20 litres.

Answer / Solution

UNSOLVED

A family of 5 people lives in a dryland that receives 600 mm rainfall per annum. To supplement their water needs, this family collects water from their rooftop which has a span of 30 m by 10m. The water needs for this family are: 20 L per person per day for bathing, 1.4 m³ per week for animal drinking, 420 L per week for washing clothes, two buckets per day for washing utensils and ten buckets daily for toiletry. If the runoff coefficient from the roof top rainwater harvesting is 90%, calculate how long (number of days) the harvested water will last this family.

Useful formulae/information:

1. A=R x K x LS x C x P
2. LS=(l/22.1 m)^m x (0.065 +0.045s +0.0065s^s)
3. V=A x R x Ro
4. One bucket has a volume of 20 litres.

Answer / Solution

UNSOLVED

1. Briefly describe the characteristics of dryland areas
2. Mention the two characteristics/ parameters used to classify dryland.
3. Describe one characteristic mentioned in (a) above.

Answer / Solution

UNSOLVED