2. DROUGHT
Drought is generally defined as prolonged
period during which annual precipitation is
less than 75% of average precipitation .
3. TYPES OF DROUGHT
Some types of droughts are
1. Meteorological drought.
2. Hydrological drought.
3. Agricultural drought.
4. CONTI…
Meteorological drought
This kind is usually determined by the
general lack of moisture in the weather such
as lack of precipitation.
It is expressed in relation to the average
conditions of the region over a long period of
time.
It is usually an indicator of potential water
crisis if the condition is prolonged.
Meteorological drought can begin and end
6. CONTI..
Agricultural Drought
This is when atmospheric moisture is
reduced to the extent that soil moisture is
affected. Here, crops and animals are
affected and evapotranspiration is also
affected.
It is often the signs one sees when a
meteorological drought is at play, but not
before a hydrological drought.
8. HYDROLOGICAL DROUGHT
Hydrological drought is associated with the effects of
periods of rainfall shortfalls on the water levels of
rivers, reservoirs and lakes, and aquifers.
Hydrological droughts usually are noticed some time
after meteorological droughts.
First precipitation decreases and some time after
that, levels of rivers and lakes decrease.
This kind of drought affects uses that depend on the
levels of rivers, reservoirs, lakes, and aquifers, such
as: hydroelectric power production, recreational uses,
ecosystems, industry, urban areas, irrigation
10. CAUSES OF DROUGHT
Droughts can occur when there is the lack of
expected precipitation (rain and snow).
Some regions are also well distributed with
surface water (streams and rivers) that have
their sources from far away mountains and
watersheds. These surface waters may dry
out if the flow from their sources upstream is
affected.
11. CAUSES OF DROUGHT
Cutting down trees (deforestation) in the
name of economics, will expose surface
water to more evaporation. It will also reduce
the ability of the ground to hold water and
make it easier for desertification to occur.
Emission of green house gases in
atmosphere result in global warming and
also in drought .
12. HOW DROUGHT EFFECTS RANGE LANDS
The effects of drought often are far-reaching,
impacting the environment and economy of an
area. Specific impacts depend on drought severity,
but often include:
o Lack of forage and drinking water
o Decreased vigor and production of plants
o Damage to plant community dynamics
o Increased wind and water erosion of soils
o Reduction and degradation of fish and wildlife
habitat
o Increased mortality of wildlife and livestock
o Increased number and severity of fires
o Reduced livestock performance
13. o In some cases hay is difficult to digest.
o Salt concentration in plants increases.
o Less nutritious food is available for
animals.
14. MANAGEMENT OF DROUGHT IN RANGE LANDS
There are some measures to be taken to
manage range land during drought.
To avoid drought
To provide hay, silage and supplements to
animals as full time food .
Let the animals to graze on less nutritious
food and then vaccinate them if it is easily
affordable.
15. Selling out of animals with least productivity
or no productivity.
16. To avoid drought:
Good land management before droughts
provides management flexibility when
drought occurs.
When drought is predicted then the hay
should be harvested before droughts and
then stored in the form of hay.
Use hay with free of weed seeds.
17. To provide hay,silage and supplements
to animal:
The animals should be fed entirely or
partially with hay and silage if affordable .
The animals are given other energy
sources like soybean extract, Wheat mids
and corn gluten meal to enhance energy
availability.
18. Let animals graze on less toxic plants
When drought comes the plant toxicity is
increased, so animal requirement can be
fulfilled by grazing them on less toxic plants
and then animals should be vaccinated .
Animals are more likely to feed on relative
toxic plants when forage is limited .
This implementation also depends on
affordability.
19. Graze animals on drought affected crops:
To graze animals on drought affected
crops that cannot be harvested profitably.
In such case the crop is used and also the
requirement of animals is fulfilled .
20. Stubble grazing:
Animals can be grazed on stubble of crops
.
Crop stubbles are remains of plant residue
after harvest.
21.
22. Selling out surplus animals
The stocking rate should be minimized so
that resources can be shared equally and
easily .
Sell young stocks .
Give priority to mature animals .
Reduction of herd size to minimize expenses.
Selling of animals before drought can give
higher price than sold during or after drought.
Reducing herd before drought allows the
increase in herd after drought .
23. Also, those animals should be kept that
can endure harsh conditions .
Quality breeding stock should be kept.
24. Moving animals
During drought animals can be moved to
non-drought conditions.
Here animals can be kept in non-drought
condition during the whole drought season
and also temporarily grazed in relative good
conditions .
