TITLE:
Assessment of the Relationships among Catchments’ Morphometric Parameters and Hydrologic Indices
AUTHORS:
Sotirios Karalis, Efthimios Karymbalis, Kanella Valkanou, Christos Chalkias, Petros Katsafados, Kleomenis Kalogeropoulos, Vasileios Batzakis, Antonios Bofilios
KEYWORDS:
Geomorphometry, Hydrologic Modeling, TOPMODEL, LISEM, Greece
JOURNAL NAME:
International Journal of Geosciences,
Vol.5 No.13,
December
16,
2014
ABSTRACT: In Greece
the hydrological analysis of ephemeral streams has been especially difficult
due to the lack of precipitation and discharge gauges. This study focuses on
the investigation of possible relationship between morphometric characteristics
of small to medium drainage basins and hydrological indices in order to
discover morphometric parameters “predictors” of flash flood potential of
ungauged catchments. Twenty-two morphometric parameters of twenty-seven
drainage basins (ranging in area between 3.6 km2 and 330.5 km2)
located in the northern part of the Peloponnese in southern Greece were
calculated utilizing GIS software ArcGIS10. Hydrological modeling was performed
using a simplified Matlab implementation of TOPMODEL, a conceptual model based
on the principle of variable contributing area to runoff production through
saturated overland flow, and LISEM, a physically based hydrologic and soil
erosion model. Rainfall-runoff simulations were performed for an extreme
precipitation event. The simulations outcomes, which include the peak
discharge, time to peak and the percentage runoff, were correlated with the
morphometric parameters of the catchments. Results were not consistent between
the two models, probably due to their different structure, with the LISEM
results being closer to what is anticipated. The results demonstrate that area,
length of the basin, perimeter and compactness factor appear better correlated
with the peak discharge (Qpeak)
of the catchment. The same parameters as well as Melton’s number correlate with
percentage runoff (C), while “celerity”
of the flood wave (length of the basin/time to peak) is better correlated with
relief, indicating that as the relief becomes greater, the response of the
basin becomes fastest.