Agricultural Drought and Its Monitoring and Prediction: Some Concepts - Monitoring and Predicting Agricultural Drought: A Global Study - page 8

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Table 1.1 Coefficients of the biometeorological time scale model

Development phase a

Co efficient PE EJ JH HS SR

1] b a 0 [ V 1 = 8.413 10.93 10.94 24.38

a 1 1.005 0.9256 1.389 -1.140

a 2 0 -0.06025 -0.08191 0

b 0 44.37 23.64 42.65 42.18 37.67

b 1 0.01086 -0.003512 0.0002958 0.0002458 0.00006733

b 2 -0.0002230 0.00005026 0 0 0

c 1 0.009732 0.0003666 0.0003943 0.00003109 0.0003442

c 2 -0.0002267 -0.000004282 0 0 0

So urce: Robertson (1968).
a PE

[8],

= = = =

planting to emergence, EJ emergence to jointing, JH jointing to heading, HS heading to soft

= do ugh, and SR soft dough to ripening.

b Fo r determination of the PE, V 1

= [ a 1 (L- a 0 )+ a 2 (L- a 0 ) 2 ] = 1.0 in equation 1.3, thus not requiring use of

a 0 , a 1 , and a 2 coefficients separately.

Line
——
12.
——
Long
PgEn

V arious chapters in this topic include variables that are used to predict
ag ricultural droughts in different regions of the world.
In the years to come, a change in average patterns of temperature and
pr ecipitation will occur due to climate change. As a result, the existing
pa tterns of drought-prone areas will undergo a transformation. Chapter 34
di scusses effects of climate change and global warming on the occurrence
of agricultural drought.

[8],

C onclusions
A gricultural drought is the most complex natural hazard, and so is its mon-
ito ring and prediction. Agricultural drought affects large areas and causes
sig nificant drops in the food production. If an effective early warning sys-
te m for monitoring and predicting agricultrural droughts can be developed
us ing weather-based variables, satellite data and crop growth models, hu-
m an and livestock mortality and decline in food production can be mini-
m ized. Although some countries in the world have established or have ini-
tia ted work on developing a drought monitoring or early warning system,
ot hers have not. Information and issues presented in the chapters of this
bo ok will help drought planners of any nation to develop or improve their
dr ought monitoring or early warning system to tackle drought situations
m ore effectively. This in turn will contribute to ensuring sustainability of
fo od production for future generations.

Re ferences
Alley, W.M. 1984. Palmer drought severity index: limitations and assumptions. J.
Climate Appl. Meteor. 23:1100-1109.