Geoscience Reference
In-Depth Information
maps and documents to collect information on land use, soil types, elevation, and
piping network for a particular drainage area (Seth et al.
2006
). This process is not
only tedious and time consuming but also very labor intensive and prone to
errors. Using spatial data to gather information on the study area is far more
technically & economically feasible and less labor intensive. GIS can be used as
a platform to present the spatial information in an electronic format. This would
provide easy access to the data at the touch of a button and also facilitate data
manipulation, data upgrade, data analysis, statistical analysis, modeling, etc. For
example, in storm-water runoff determination, GIS can also facilitate better under-
standing of the drainage pattern of the study area as the drainage areas may be
overestimated or underestimated depending upon lack of spatial information
(Seth et al.
2006
). According to Djokic and Maidment (
1993
), GIS is seldom the
environment into which water system analysis methods are directly implemented.
GIS can preprocess data for urban water models. The urban water models have
wider capabilities w.r.t. the GIS software in regards to problem solving capabilities.
The natural geographic features/boundaries of the hydrologic basin can be used as
boundary conditions of a mathematical model (Sample et al.
2001
). This facilitates
examination of a wider range of alternatives and provides a living management that
can be modified and updated once the watershed conditions change (Xu et al.
2001
).
Needless to say this realization has lead to the marriage of mathematical drainage
models and GIS. According to Pullar and Springer (
2000
), incorporation of catch-
ment models into GIS has lead to streamlining data input and better interpretation of
model outputs. Therefore, GIS is a valuable and frequently indispensable tool for
water-related environmental planning and management (Tsihrintzis et al.
1996
).
Linking an urban storm-water runoff model and a low cost, PC-based GIS
raster package can facilitate preparation, examination, and analysis of spatially
distributed model inputs and parameters (Meyer et al.
1993
). The same GIS
package can also facilitate the display of the model results. GIS offers front-end
or back-end applications of existing hydrologic models where front-end applica-
tions include the computation of watershed parameters for existing hydrologic
models and back-end applications include the cartographic display of computed
hydrologic simulation results (Xu et al.
2001
; Shamsi
1996
). Once the spatial data
has been processed by GIS it can be fed into the urban water model for analysis.
Analyses can also be done in the GIS itself to understand the changing spatial
patterns of the data. Once the urban water model gets the processed data then it can
be modeled using different management scenarios and strategies. The impacts of
different urban water management strategies vis-`-vis the spatial data can be
studied so as to understand the model better and choose the best strategy. Once
the model has successfully modeled the strategy the resulting spatial output can
be displayed with the help of GIS. Today there are a number of urban water
management models available which can be integrated with GIS for analyzing
water management strategies.
The coupling of GIS and water management models leads to information
exchange between GIS and the model. There are several types of coupling between
an environmental model and GIS and these can range from a loose coupling to a
