In: Wagner W., Székely, B. (eds.): ISPRS TC VII Symposium - 100 Years ISPRS, Vienna, Austria, July 5-7,2010, IAPRS, Vol. XXXVIII, Part 7B
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HYDROLOGICAL SIMULATION OF MAHANADI RIVER BASIN AND IMPACT OF
LAND USE / LAND COVER CHANGE ON SURFACE RUNOFF USING A MACRO
SCALE HYDROLOGICAL MODEL
V.K. Dadhwal 3 , S.P.Aggarwal b ’* and Nidhi Mishra b
a National Remote Sensing Centre, Balanagar, Hyderabad - 500 625, India
b Indian Institute of Remote Sensing (NRSC), 4, Kalidas Road, Dehradun - 248 001, India
KEY WORDS: Hydrological Modelling, Landuse Landcover Change, Variable Infiltration Capacity Model, Remote Sensing
ABSTRACT:
In the present study, Variable Infiltration Capacity (VIC) a macro-scale hydrological model was used to simulate the hydrology of
Mahanadi river basin of India. The analysis was carried out for the impact of land use/ land cover (LULC) changes on stream flow
pattern. Surface runoff was simulated for the year 1972, 1985 and 2003 to quantity the changes that have taken place due to change
in LULC. An increase by 4.53% (3514.2 x 10 6 m 3 ) in the annual streamflow was estimated at Mundali outlet of the Mahanadi basin
from 1972 to 2003. This may attributed due to decrease in forest cover by 5.71%. The validation of VIC model showed a close
agreement between the observed and simulated runoff values with the Nash-Sutcliffe coefficient of 0.821 and relative error of 0.085.
1. INTRODUCTION
Water resources management requires a systems approach that
includes not only all of the hydrological components, but also
the links, relations, consequences and interactions amongst all
the components. Human modifications of the environment,
including land cover change, irrigation, and flow regulation,
now occur on scales that significantly affect seasonal and yearly
hydrologic variations. It thus becomes necessary to understand
and quantify various hydrological components of the catchment
for efficient water resource management. Runoff representing
the response of a catchment to precipitation, reflects the
integrated effects of a wide range of landcover, soil,
topography, climate and precipitation characteristics of the area.
Hence, if one has to study the impact of changes in climate and
landcover on basin hydrology, altering streamflow pattern is an
important component to investigate.
Quantification of runoff and other hydrological components can
be done in many ways; Hydrological modeling is one efficient
way for consistent long term behavioral studies. Hydrological
modelling is a mathematical representation of natural processes
that influence primarily the energy and water balances of a
watershed. The fundamental objective of hydrological modeling
is to gain an understanding of the hydrological system in order
to provide reliable information for managing water resources in
a sustained manner. Powerful spatially-distributed models are
based on physical principles governing the movement of water
within a catchment area, but they need detailed high-quality
data to be used effectively. AVSWAT (ArcView Soil and Water
Assessment Tool), MIKE-SHE, Variable infiltration Capacity
(VIC) model, HEC-HMS (Hydrologic Engineering Centre-
Hydrologic Modelling System) are some of the physically based
distributed hydrologic models.
In the present study, VIC land surface hydrologic model has
been used for modeling the river flow regime. It is a physically
based, macroscale hydrological model which represents the
partitioning of incoming (solar and long wave) radiation at the
land surface into latent and sensible heat, and the partitioning of
precipitation (or snowmelt) into direct runoff and infiltration.
VIC explicitly represents vegetation, and simultaneously solves
the surface energy and water balances. A river routing model
when coupled with VIC permits comparisons between the
model-derived discharge and observations at gauging stations.
Further details of the VIC model can be found in Liang (1994);
Liang et. al, (1994); Liang et al. (1996); Lettenmaier (2001). An
attempt has been made to model and evaluate the changes in
streamflows attributable to changes in landcover throughout the
Mahanadi basin. For an understanding of the distribution of the
physical characteristics of such large catchments with little
available data, a better insight can be provided by remote
sensing techniques. The remote sensing data and GIS have
already been used by hydrologists to deal with large scale,
complex and spatially distributed hydrological processes.
Remote sensing has held a great deal of promise for hydrology,
mainly because of the potential to observe areas and entire river
basins rather than merely points.
2. STUDY AREA
The river basin at the appropriate scale is generally the most
logical geographical unit of streamflow analysis and water
resources management. In the present study, Mahanadi River
basin has been selected as study area. The Mahanadi basin
encompassed within geographical co-ordinates of 80°30' to
86°50' East longitudes and 19°20' to 23°35' North latitudes as
shown in Fig. 1. The total catchment area of the basin is
1,41,600 km 2 . The average elevation of the drainage basin is
426 m with a maximum of 877 m and a minimum of 193 m.