Geoscience Reference
In-Depth Information
Fig. 1 A flow direction map of discharge waste materials and chemicals from pollutant sources
into the river. Yellow circles indicate there is a conflict and wrong flow direction produced by D8
algorithm
a large area within a short period. Currently, more than 200 LiDAR systems are
available all over the world and can achieve up to 250,000 pulses per second and
with different type of sensors that fit variety of purposes (Schuckman and Renslow
2009
). In terms of accuracy, LiDAR systems, such as aero-space service, are able
to reach up to 15 cm RMSE ground surface (Hodgson and Bresnahan
2004
).
Even though a very high data accuracy such as LiDAR or high resolution
remote sensing satellite imagery are used, the information on surface water flow
directions are still in the same range of accuracy. It is the nature of hardware
development must coincide with software, while data development (accuracy of
new data acquiring methods) with the processing algorithm development.
At this moment, the overall SFD output of flow direction information could not
be provided at the best level of accuracy to the specific application due to the
unenhanced algorithms. Thus, there is a need to upgrade and improve SFD
algorithms such as D8 to simultaneously catch up with the development of data
acquisition techniques in order to provide the most accurate information related to
the surface water flow direction.
The study focuses on SFD model especially for D8 algorithm. So, basically this
paper tries to dig the limitations of D8 algorithm, how a new D16 algorithm can be
designed to overcome those weaknesses and some comparison results from various
comparison methods. As summary, this study is mainly conducted to develop and
test a new designed algorithm for surface water flow direction called ''D16 Water
