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produce less than 1/5 of total economic return in the basin area.
At the same time, they generate significant nonpoint source
pollution problems. Since agriculture has been developed to a
matured level, and the related management measures can only
partly mitigate the environmental problems, it is suggested that
the agricultural activities and the related pollution concerns may
not fluctuate with time so significantly as other activities (e.g.
tourism and industries). As an example, Figure 7 presents the
solution for vegetable farming.
Figure 7 Planning for vegetable farming
For industrial activities, cigarette industry contributes to the
majority of regional economy with relatively low pollution
potential. Food processing industry would be promoted since it is
needed for supporting tourism development and for
corresponding to improved living standard. Figure 8 shows
planning for the food processing industry. For the other
industries, pulp, chemical fibre and leather production generate
large amounts of organic pollutants (with high COD
concentrations) under the existing technologies. It is suggested
they be significantly reduced or cut. For textile, paper and
cement industries, it is recommended that their status would be
flexible from short-term management point of view. Since the
study system is now with demanding environmental conditions, a
relatively conservative strategy may be desired. Therefore, from
long-term planning point of view, it is suggested that those
industries’ further development be limited. At the same time,
development of high-tech industries with low or no pollution
impacts would be encouraged
alternative for this type of activity is to develop fish ponds out of
the lake. Number of vessels for in-lake fishing and navigation
should be limited to reduce direct sewage/waste discharge into
the lake. Sanitary toilets should be installed within the existing
vessels. Also, public lavatories with sanitary facilities should be
constructed at docks for the vessels, with the sewage being
collected and treated periodically.
CONCLUSION
(1) In this study, a hybrid GIS-supported watershed modeling
system is developed for integrated planning of water pollution
control in the Lake Erhai Basin. This system consists of three
major components: database, modelbase, and user interface.
The modelbase includes three aspects: (i) simulation models for
bridging source/impact factors and the related water quantity and
quality; (ii) an optimization model for compromising a variety of
system objectives and generating desired decision alternatives;
and (iii) post-modeling analysis for further trade-off analysis and
risk assessment. The GIS technology is chosen as a basic tool
throughout the modeling process. It allows smooth
communication among the database, the models and the users.
(2) An inexact-fuzzy multi-objective programming (IFMOP) model
is developed as a planning tool. It can effectively reflect
uncertain, interactive, and multiobjective features of the study
system. The inexact solutions provide decision-makers with a
flexible decision space, and are useful for further risk analysis.
Three decision alternatives are generated by adjusting decision
variable values within their solution intervals.
(3) An important advantage of this study is its real-time feature.
When environmental and socio-economic conditions are
significantly changed in the future (e.g. when an unexpected
large project is developed in the basin area two or three years
later), the provided planning alternatives may become not
applicable. Consequently, updated alternatives need to be
provided. For the previous environmental planning, the provided
reports may become useless, and a new planning project may
have to be initiated again. In comparison, this study provides not
only research reports for planning based on the existing
information, but also a set of flexible computer software
packages. Thus, when conditions are significantly changed in the
future, local engineers/planners can input updated information
into the computer-managed database, run the user-friendly
modelling software, and obtain a new set of planning alternatives
through the provided graphic interfaces.
cessing Industry
—r caps mOST""""
Figure 8 Planning for food processing industry
Net-cage fish culture should be cut due to its significant
contribution to N and P pollution problems in the lake. An
(4) This study is the first integrated environmental planning study
in China. Comprehensively and quantitatively, it provides
planning schemes based on development/application of a set of
effective decision-support methodologies. The provide software
and part of the recommended schemes have been used by the
local authorities in their management practices.
ACKNOWLEDGEMENT
This research has been supported by the United Nations
Environment Programme and the Natural Sciences and
Engineering Research Council of Canada.
REFERENCES
Bicknell, B.R., et al. (1997), Hydrological Simulation Program-
Fortran: User’s manual for version 11. USEPA, National
Exposure Research Laboratory, EPA/600/R-97/080.