Types of gis in modelling in water contaminants
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Answer:
Water pollution accident is a major type of China’s
environmental accident. It not only causes water quality
deterioration and ineffective use of water resource, but also
affects the normal activities of economy and society and does
serious harm to the water ecological environment. After a
water pollution accident occurs, the pollutant enters the river
and migrates with water current. During the transportation
process, pollutant is influenced by hydraulics, hydrology,
physics, chemistry, biology and other factors (Song, X. Sh.,
Deng, W., 2004), there is nonlinear relationship among these
factors which is difficult to be expressed by conventional
dynamics method. The migration and conversion of pollutants
in the water pollution accident is typically a dynamic, complex,
nonlinear system.
Dynamic systems are often hard to understand and difficult to
model because of the interactions among the spatial elements,
and the changes in the structure and function of the system
over time. Traditional modelling approaches focus on either
temporal or spatial variation, but not both (Ahmad, S.,
Simonovic, S. P., 2004). In order to better simulate dynamic,
complex systems, we should be aware that the system
performance in time is affected by the change of conditions in
space. So we need to focus on both temporal and spatial
variation. During the emergency response of water pollution
accidents, the management department needs to understand the
migration situation of pollution slick and the changes of
pollutant concentration in both time and space as soon as
possible to take effective emergency measures. Therefore, it is
very important to construct a water quality model with the
capability of simulating the pollutant concentration changes in
both time and space simultaneously, and help decision-makers
to grasp the change trends of accidents in two dimensional
spaces (Zhang, B., 2007).