TITLE:
Mapping Potential Infiltration Patterns Using Digital Elevation Model
AUTHORS:
Haris Hasan Khan, Arina Khan, P. D. Sreedevi, Shakeel Ahmed
KEYWORDS:
DEM, Permeability, Infiltration Capacity, Drainage Density, Autocorrelation
JOURNAL NAME:
Journal of Geographic Information System,
Vol.6 No.4,
August
12,
2014
ABSTRACT: This study attempts to
simulate the spatial heterogeneity of infiltration in a drainage basin using
digital elevation models. Infiltration capacity is one of the controlling
factors in the formation of stream channels. Channel formation is also a
function of the slope and the contributing area. Natural stream channels, if
properly graded and adjusted to the present climate, reflect the interactions
of local slope, contributing area, and permeability of surface materials.
Channel networks can be delineated from a Digital Elevation Model (DEM) using a
variety of algorithms using different thresholds for channel initiation. These
algorithms delineate a channel network on the basis of local slope, curvature,
and contributing area, without considering the permeability of surface cover.
Hence, the difference in the structure of the two drainage networks,i.e.the surveyed drainage network obtained
from field observation and the simulated network generated from the DEM, is
indicative of the spatial heterogeneities in the permeability of the surface
cover as shown in this paper. Spatially variable drainage density maps
corresponding to the two networks have been used here to obtain normalized
difference maps that characterize the potential infiltration anomalies within the
catchment. The simulated spatial pattern is compared with the actual
infiltration measurements in the field using infiltration tests. Strong
positive correlation between the observed and modeled infiltration confirms the
effectiveness of this technique in the rapid assessment of potential
infiltration variability.