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Doctorat
Inde
2000
Stochastic Modelling Of hydrological Drought In Pennar Basin
Titre : Stochastic Modelling Of hydrological Drought In Pennar Basin
Auteur : Radha Krishna Murthy.B
Université de soutenance : Sri Venkateswara University
Grade : Doctor of Philosophy (PhD) 2000
Conclusions
per Pennar Project stream flows.
9.2 Conclusions
Conclusions drawn from the rainfall-runoff relationship study are,
i. There exists a strong correlation between present month runoff and
present month rainfall.
ii. Study revealed that number of rainy days can be excluded from the
regression analysis and
iii. Results obtained from co-axial graphical correlation are comparable with
that obtained from regression analysis.
The following conclusions are drawn from the modeling of annual rainfall in the
basin,
i. Autoregressive models preserve mean, standard deviation of historical
series.
ii. The choice of the model depends on the degree of complexity. As ARI
model satisfy all the criteria, it is used in simulating the drought in the
basin.
The following paragraphs enunciate the conclusions drawn from the modeling of
drought using annual rainfall series.
i. The rainfall in the basin is positively skewed. The negative first correlation
coefficient indicates high rainfall years followed by low rainfall years and
vice versa.
ii. All stations have identical coefficient of variation indicating the
homogeneity of region with respect to rainfall.
iii. Wide range of variation of coefficient of variation, skew and first
correlation coefficient signifies that rainfall series are not independent
normal.
iv. Entire basin is drought prone from mild to severe intensity.
v. Duration of mild drought varied from 3 to 10 years, whereas for moderate
drought it varied from 1 to 7 years and for severe drought is one year
only.
vi. The study reveals the suitability of transformation functions to normalize
the series (Box-Cox and TSPT). For obtaining the truly normal series it is
necessary to use both transformations.
vii. Gumbel distiribution fits well for rainfalllstream flow drought severity and
duration. Log nonnal distribution fits well for the case of drought severity
only.
The identified droughts by modified procedure of Herbst et.al (1966) are
concurrent with historicilly realized droughts, thus providing the viability of the
methodology in identification of drought conditions.
It is hoped that the present study can be applied with confidence to characterize
the drought in the long term perspective of water resources planning and management
of Pennar basin.
Page publiée le 30 septembre 2016, mise à jour le 1er février 2021