Theoretical Background - Response of Flood Events to Land Use and Climate Change - page 11

Chapter 2
Theoretical Background
2.1 Introduction
With respect to the literatures and previous researches, this chapter gives a
comparative overview of the major challenges faced when dealing with flood
hazard. First, definition, source and implication of digital elevation model are
explained, and then the focus is on application of different interpolation techniques
in drainage network estimation, coupled with advantages and disadvantages of
these methods and their application in different research fields. Flood hazard,
concepts, definition, types, and causes are defined in the next parts. This chapter
also provides a background to climate change and land use change from global to
local (Barcelonnette area) which was estimated and interpreted based on different
scientific researches.
2.2 Digital Elevation Model: Sources and Implications
Topography representing as digital elevation model (DEM) is an important land-
surface characteristic that affects most aspects of the water balance in a catchment,
including the generation of surface and sub-surface runoff; the flow paths followed
by water as it moved down and through hill slopes and the rate of water movement.
All of the spatially explicit fully distribute hydraulic and hydrological models as
well as hydrological decision support systems use topography (represented by
DEM of the area modeled) to derive bathymetry [ 1 ].
Many applications depend on the shape represented by the DEM rather than the
absolute elevation values. These include hydrological applications, for which an
accurate representation of surface drainage structure is critical [ 2 , 3 ]. Computation
of terrain corrections to observed gravity data and remotely sensed data is another
important application that depends primarily on the representation of terrain shape.