Geology Reference
In-Depth Information
1.1 Modelling in Hydrology
The known history of hydrology began around 5,000
6,000 BC. Evidence of this
can be seen from the construction remains of canals, levees, dams, subsurface water
conduits, and wells found in the Nile region of Egypt and Indus region of India.
Nile river
-
flow was monitored by the Egyptians as early as 3,800 years ago and one
famous Indian scholar Kautilya used rainfall measuring instruments approximately
2,400 years ago [
32
]. The Roman architect Marcus Vitruvius made the first attempt
to give a philosophical de
nition to the theory of the hydrologic cycle. More
scienti
c studies on the hydrologic cycle were initiated in the seventeenth century,
by the French scholars Pierre Perault and Edme Marriotte. By 1700, a British
scientist Edmund Halley contributed to the work of Perault and Marriotte by esti-
mating the quantity of water involved in the hydrologic cycle of the Mediterranean
Sea and surrounding lands. The term
received acceptance among
scholars in its current meaning by around 1750 [
68
]. The eighteenth century wit-
nessed the application of mathematics in hydrology and development of new
dimensions of hydrology named
“
hydrology
”
fluid mechanics, and hydraulics by scientists like
Pitot, Bernoulli, Euler, Chezy, and many more. The understanding of hydrological
cycle and processes involved were solidi
ed by the work of a British chemist John
Dalton by the year 1800 [
24
]. The ground breaking innovation in hydrology
occurred in the 18th century with the work of the Dutch-Swiss mathematician
Daniel Bernoulli, which included the Bernoulli piezometer and Bernoulli
s equa-
tion. The 19th century saw the development in groundwater hydrology, including
Darcy
'
ow
equation. Hydrology had a close connection with civil engineering from the early
days of development. During the 19th century, researchers started examining
relationships between precipitation and stream
'
s law, the Dupuit-Thiem well formula, and Hagen-Poiseuille
'
s capillary
flow. That information was used as a
guideline for designing bridges and other structures. Daniel Mead published the
first English-language text in hydrology in 1904 and Adolf Meyer followed with his
text in 1919. Both publications were written for civil engineers. Rational analyses in
hydrology began to replace empiricism in the 20th century and many organizations
like International Union of Geodesy and Geophysics (1922), Hydrology Section of
the American Geophysical Union (1930), which promotes researches in hydrology,
were set up in the
first half of the 20th century [
55
]. The second half of the 20th
century witnessed the diversi
ed application of techniques in the
field of hydrology
which includes statistical applications and arti
cial intelligence. Even now, in the
21st century, hydrology is developing day by day adding new concepts and
approaches. The hydrological community is eagerly waiting for new breakthroughs
and eminent deviations in hydrological science.
Hydrological models are mathematical representations of part or whole of the
hydrological cycle in which processes involved in the transformation of climate
inputs, such as precipitation, evapotranspiration, solar radiation and wind, through
atmospheric, surface and subsurface transfers of water and energy into hydrological
outputs like runoff, water level, etc. Singh and Woolhiser [
83
]de
ne hydrological
