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Iranian Journal of Environmental Health, Science and Engineering
Iranian Association of Environmental Health (IAEH)
ISSN: 1735-1979
Vol. 4, Num. 2, 2007, pp. 99-106
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Untitled Document
Iranian Journal of Environmental Health Science & Engineering,Vol.
4, No. 2, 2007, pp. 99-106
DEVELOPING A WATER QUALITY MANAGEMENT MODEL FOR KARUN AND
DEZ RIVERS
*1M. Afkhami, 2M. Shariat, 3N. Jaafarzadeh, 4H. Ghadiri, 5R. Nabizadeh
1Islamic Azad University, Sciences and Research Branch, Ahvaz, Iran
2Science and Research Campus, Islamic Azad University, Tehran, Iran
3Ahvaz Jondishapoor Medical Sciences University, Ahvaz, Iran
4Nathan Campus, Griffith University, Queensland, Australia
5Department of Environmental Health Engineering, School of Public Health,Medical Sciences/University of Tehran, Tehran, Iran
*Corresponding author-Email: info@mehranafkhami.com Tel: +98 611 3365219,
Fax: +98 611 3388474
Received 10 January 2007; revised 30 February 2007; accepted 25 March 2007
Code Number: se07015
Abstract
The Karun and Dez rivers basin are the largest rivers basin in Iran which
are situated in the south west of
the country. Karun River originates from Zagros mountain ranges and passing
through Khuzestan plain,
reaches the Persian Gulf. Several cities lie along its path of them the most
important is Ahvaz, the center
of Khuzestan province. To achieve water quality goals in Karun and Dez rivers,
a water quality
management model has been developed through the GIS approach and a mathematical
water quality
model. In Karun and Dez rivers, water quality has decreased due to heavy pollution
loads from Khuzestan
province cities and surrounding areas. In this survey, pollution sources, land
use, geographic features an
measured water quality data of the river basin were incorporated into the Arc-view
geographic
information system database. With the database, the model calculated management
type and cost for each
management project in the river basin. Until now, river management policy for
polluted rivers in Iran has
been first of all to get penalties from pollution sources and secondarily,
to construct treatment plants for
the pollution sources whose wastewater is released untreated and for which
the wastewater quality goal of
the Iranian Department of the Environment is not met. Different management
projects with a time
program were proposed and they were compared with the results of the river
quality without any
management approach. It became clear that the results based on the management
approach were much
better than those for the unmanaged condition from the viewpoint of the achievement
of water quality
goals and cost optimization.
Key Words: Dez, Karun, management model, quality, river, water
INTRODUCTION
More than one third of Iran's total surface
water of 94 billion m3 is flowing into the
Khuzestan province but ironically most of its inhabitants
are suffering from poor quality drinking water, especially during the summer months. More
than 70% of the four million population of the
khuzestan province, which includes the inhabitants of
the provincial capital city of Ahvaz and the two
major port cities of Abadan and Khoramshahr, are dependent on Karun river and its subsidiaries (KWPA, 2000 and 2001). According to the
World Commission on Dam's report (WCD, 2000), Iran with 7.2 million hectares of land under
irrigation agriculture is the largest in the Middle
East, followed by Turkey (42 million ha) and Iraq
(3.5 million ha). A large proportion of Iran's
irrigated lands are in the Khuzestan province. Country
wide 90% of Iran's freshwater needs are from groundwater sources and only 10% from
rivers. In Khuzestan province however the opposite
is true as 85% of its freshwater need is provided
by rivers and only 15% taken from groundwater. Five rivers with the total annual capacity of 31
billion m3/annum flow into the Khuzestan plain,
among them, Karun, with 22 billion m3/annum being
by far the largest and also the longest river (860
km) in the province and in the country as a whole.
The overall size of the Karun's catchments is
65,230 km2. Karun originates from the Zagros
mountain range on the western borders of Iran and 460
km of its 860 km journey to the Persian Gulf is in Khuzestan's alluvial plain where
irrigated agriculture has at least a 3000 years history.
As shown in Fig. 1, for the last 60km of its
journey, Karun joins Tigris and Euphrates which flow
in from the Iraqi side of the border, to form a
large shipping waterway called Arvand River
(Shiva, 2002). In this study, a GIS based
management model was introduced to take into account
the characteristics of the water quality
management projects and the cost function. To
date, conventional mathematical programming such
as linear programming, non-linear programming, dynamic programming and integer
programming have been used to solve the problems for
regional water quality management. Revelle et
a1., (1968) developed a river Water Quality
Management Model (WQMM) using linear programming.
The principal constraints prevented violation of
the dissolved oxygen standards and the results of
the model were compared with those based on dynamic programming. While Liebman and
Lynn (1966) and Klemetson and Grenny (1985)
utilized dynamic programming, McNamara (1976) and Fujiwara (1990) developed a
deterministic WQMM by non-linear programming. A
WQMM was also developed with integer programming (Bishop and Grenny, 1976; Burn, 1989)
using transfer coefficients to constitute
constraint equations. Lohani and Thanh (1979)
considered river flow as a random variable and a
probabilistic WQMM was constructed using the
DO-sag equation. Fujiwara et al. (1987) constructed
an optimisation problem of linear programming
using the Streeter-Phelps equation, Lee and Lin
(2000), their recursive equation and a cumulative probability density function of river flow.
Genetic Algorithms (Goldberg, 1989) imitate the
genetic evolution process of creatures in nature in
order to determine the global optimum in mathematical programming. Genetic algorithms (GA) have
some practical advantages. First, the concept is
very simple and easy to understand and it can be
applied to many problems for which traditional mathematical programming techniques
are intractable. Second, its searching strategy is
very efficient and, according to the theory, it will
finally find the global optimum solution. Chen and
Chang (1998) did introduce a GA to solve a
non-linear fuzzy multi-objective programming model, but
they only considered Biologycal Oxygen Demand (BOD) and Dissolved Oxygen (DO) as
water quality parameters and the water quality calculation was based on the
Streeter-Phelps equation. The first objective of this research
was to develop a WQMM to achieve specific water quality goals (Krenkel and Novotny, 1980) and
the optimization of management projects costs.
Most WQMMs can calculate BOD and DO as a standard. For the purpose of this study,
nitrogen and phosphorus were included in the
management model of this study as well as BOD and DO.
With a management approach exact output from the mathematical water quality model can be used
in this management model. The second objective was to apply this management model to the Karun
and Dez river, which is heavily polluted, and
identify whether the management approach
outperforms other approaches. From the application result,
a regional water quality management plan would be designed to improve the river water quality.
Among various sources of pollutants, the focus was
placed on the pollutants from domestic, agricultural
and industrial wastes, which are the most
important factors in the river basin.
MATERIALS AND METHODS
This study has been done in Khuzestan
province, south west of Iran (Fig. 1). A literature
review was made through searching in books, journals
and different papers. 20 stations were selected at Karun and Dez rivers; then twelve samples
were collected monthly from each station. The
samples were transferred to the laboratory and
were prepared for analysis. The main reference for experimental issues was standard methods for
the examination of water and wastewater. SPSS and Minitab software were used to perform a statistical analysis of the results.
A WQMM, in which water quality calculation results from
the Qual2e model (Brown and Barnwell, 1987) were accurately reflected in the optimization
problem whilst considering various water quality parameters such as BOD, DO, total nitrogen
(TN) and total phosphorus (TP). The management model was applied to the Karun and Dez
rivers where water quality is so poor that a comprehensive countermeasure for water
quality restoration is necessary. The Arc-view
geographic information system (GIS) was used to
estimate pollution loads for the river basin.
At the end after developing a WQMM to
achieve specific water quality goals (Krenkel and
Novotny, 1980), introduction of management projects
and their cost optimization have been done.
RESULTS
Salt in the soil profile and groundwater
Alluvial deposits in Karun and Dez river
system, and three other smaller rivers, have resulted
in the formation of Khuzestan plain. The plain is
very flat and the rivers are prone to regular
flooding despite the fact that both Karun and Dez
are regulated by a number of large hydro-electric dams. The soil profile is very rich in salt
deposits and groundwater is both shallow and highly
saline (Ghadiri, 1985; Ghassemi et al., 1995). From
about 40km north of Ahvaz where the watertable is
less than 1.5m deep, salt accumulation on the soil surface is clearly visible on the surface. As
the groundwater table becomes even shallower
further south, soil salinity is further widespread.
(Afkhami, 2003). The 120 km distance between Ahvaz
and Khoramshahr consists almost entirely of highly saline soils with heavy texture and
high groundwater table of 0.60-1m. five new large sugar cane projects with the total area of
70000 hectares, have been planned for this region
(Fig. 1). Groundwater hydrology of the Khuzestan
plain also appears to have played a major part in
land degradation during the great Persian Empire of
2 to 3 thousand years ago. Remnants of irrigation canals from that era can still be seen in
regions around Ahvaz, an indication that the land was
being used for agriculture but rising ground water
and the salinization forced farmers to abandon the lands and move further north or towards
Mesopotamia. Now after more than 2000 years, the
government of Iran is trying to leach the salt out of the
soil profile and resurrect agricultural activities to
these salt affected lower regions of the Khuzestan
plain, a very costly exercise with a very doubtful outcome.
Agriculture
Agriculture is by far the biggest consumer
and polluter of the Karun river. Table 1 shows the current and predicted water consumption by
the three main users of the Karun river. The total
water consumption of agriculture and fish farming activities is currently around 10 billion
m3/annum with plans to expand this amount by
approximately 80% over the next 10 years. In the
Agricultural sector, the main contributors to the
deterioration in water quality are large agro-business units
in Dezful region, large scale government owned sugar cane plantations with their modern
irrigation and drainage systems and private farms and
fish farms established along the Karun and Dez
river system itself. By far the biggest single
problem that the Karun river is facing is its rising level
of salinity which is already above the drinking
water limit (WHO, 2004) for several months of the year for the two downstream cities of Abadan
and Khoramshahr. Prior to growing sugar cane in
these five new multi-million dollar projects, an
elaborate and expensive drainage system has to be put
in place and salt has to be washed down the soil profile and into the drainage system through
the ponding technique.
Industrial effluents
Khuzestan is the most industrialized province
of Iran and more than 25% of Iran's heavy
industries are located there. Most water polluting
industries of Iran such as the petroleum industry, gas
and sugar refineries, petrochemical factories,
paper mills, gas and petroleum based power plants,
steel plants and other heavy industries are built in
and around the provincial capital city of Ahvaz on
the banks of the Karun river. As well as using
Karun water for their needs, these industries release
their sewage effluent directly into this river
mostly without any treatment. Further downstream of
the river and near the twin port cities of Abadan
and Khoramshahr, where the Karun joins the
Euphrates and the Tigris rivers, large petrochemical
plants, petroleum refinery, soap factory and many
others further contribute to the degradation of
water quality in the Karun. In total, more than 315
million cubic meters of industrial sewage effluent
directly enters into Karun river annually.
Municipal effluent
The majority of Khuzestan's population of 4
million is directly dependent upon Karun for their
drinking and sanitary water consumption. Municipal sewage from several large and small cities
such as Ahvaz, Abadan, Khoramshahr, Dezful, Shoushtar, Mahshahr, and Masjed-Soleiman
enters the river. Table 2 shows the volume, flow
rate and the salinity (Electric Conductivity, EC) of
some of the sewage discharge entering Karun river
in an untreated form from these municipalities.
Seawater intrusion
The border river of Arvand Rood, which is
formed when the Karun and the two Iraqi rivers of
Tigris and Euphrates join together, as well as being
a major shipping waterway for both countries, irrigates the largest date palm plantation in
the world. In recent years both Iran and Iraq have significantly increased water uptake from
their respective rivers resulting in a decrease in the
flow rate in Arvand Rood. This has lead to an
increase in the distance upstream that sea water is
now capable of reaching during the high tides.
During the drought years of 1998-2001 sea water
backed up to the main pumping stations of the city
of Abadan severely contaminating its drinking
water supply. The date palm plantation industry
has already been damaged by the steady rise in
river salinity. Seawater intrusion, if it continues,
will ultimately destroy both countries' multi-million
dollar date export industry given time.
Water quality model and pollution load
QUAL2E was chosen as the water quality
model for this study because it is a one dimensional
steady state model and it is easily applicable to this
type of management. Modeling was performed from the Shahid Abasspoor and Dez
Dams, which are located in the upper parts of the rivers, to
the estuary bank as shown in Fig. 1. The main
river channel was divided into 5 reaches.
Hydraulic calculations in the QUAL2E model were performed with the depth-flow
and velocity-flow equation (Brown and Barnwell, 1987). Initially,
the model was calibrated using the data set
observed at the Karun river in 1999 from Karun
river waterway project. Immediately after joining
the effluent flow of the Karun Dez river. However the calculated BOD and DO
were lower than those observed in 1999. Likewise, the water quality data for
stations observed on different sampling dates were also compared with the
calculated values. Data sets of the model for
verification including point source pollutant loads and
stream flow were prepared based on conditions in
October 2002 till September 2003. Unfortunately, as a
large volume of water is needed for agricultural use
in some special months, thus, the fluctuation of
the river water quality is very high, and it was
difficult to use the observed data for that particular
date for verification. For BOD and DO, the
calculated results show quite a good correspondence with the standards. To obtain
pollution load data from point sources and incremental inflows in the
model, the basin was divided into 5 sub-basins using Arc-view spatial analyst
pollution loads from
each sub-basin were estimated using a 180m*180m
grid based database compiled from the pollution sources data. Based on the
unit load approach, pollution loads from point sources and
non-point sources were estimated using the Arc-view GIS.
The pollutant removal rate of
management projectswere taken into account when
estimating the pollution loads from the WQMM with pollution loads of each reach
calculated from delivery ratios (the ratio of the mass of pollutants delivered
to
a stream divided by the mass of pollutants
generated at the source (Novotny and Olem, 1994)).
Proposed management options
In this section, the proposed management
options for water pollution control of the Karun-Dez basin are presented. These options have been
identified and proposed through the cooperation of
experts and the stakeholder organizations and agencies
in the study area (Fig. 2). The proposed options, which should be implemented during a 10
years timeframe, have been categorized into three groups, namely direct, indirect, and
supporting projects. The general characteristics of
these projects are presented below:
Direct projects
Direct projects are those which can
directly improve the river water quality. The
direct projects are classified into industrial, domestic, and agricultural
sectors as follows:
- Industrial Sector: The proposed direct
projects for the industrial sector have been
presented considering the following main categories:
- point source reduction
- improved solid waste disposal
- reduction of water withdrawal from
Karun river and
- control of miscellaneous polluter
As most of the industrial point loads are
violating the wastewater discharge standards of
Iranian Department of the Environment, point
source reduction will have significant effect on the
Karun river water quality.
- Domestic sector: The proposed direct
projects for the domestic sector have been
prepared considering source reduction as the main objective.The most important proposed
projects that can improve the river water quality
for the domestic sector are:
- implementation or completion of
wastewater collection and treatment systems for cities
in the study area and
- separation of biomedical wastewater of
hospitals located in the study area and surface
runoff management in urban areas.
- Agricultural and Agro industrial sector:
The direct water pollution reduction projects for agricultural and agro industrial sector
have been prepared considering source reduction as the main objective. These projects
are categorized into two sections, namely
pesticide and fertilizers pollution reduction, and deployment of modern irrigation projects
of agricultural return flows. The most important proposed projects for agricultural and
agro-industrial sector are:
- improvement and optimization of the
crop pattern and irrigation systems,
- using the resistant and plentiful seeds,
- reducing the application of pesticides
and chemical fertilizers in agricultural lands,
- use of suitable pesticide and fertilizers
in agricultural networks,
- transferring agricultural return flows,
- recycling and reuse of agricultural wastewater,
- watershed management
- reduction of the pollution loads of the
hatchery projects.
Indirect projects
Indirect projects are those which can
indirectly reduce the river water pollution. These
projects can also provide a long term stability in water
supply and demand and restore the ecological
condition of the system. The most important indirect
projects are proposed are:
- review of inter basin water transfer projects
to create balance between water supply and use,
- development of the infrastructure needed
in the domestic sector such as improvement of the domestic water supply system,
- improving the domestic water use pattern,
- separation of drinking and non-drinking water
- reducing water losses.
Supporting projects
The supporting projects are aimed at providing
the basic information and research background
needed for the implementation, monitoring, and
evaluation of the master plan of water pollution reduction
of Karun river. The supporting projects have been proposed considering the following objectives:
- development of a water quality
monitoring network
- man power capacity expansion and
behavioral improvement of existing institutional framework
- Policies and rules scientific and research
based approaches.
Successful implementation of the
agricultural water pollution reduction projects will reduce
the concentration of pesticides and total
dissolved solids in agricultural return flows as well
as improving the irrigation efficiency by up to 20 percent. The pollution
load reduction for each sector has been estimated using the
hierarchical structure and the relative weights of water
quality variables. Based on the results of this study,
which are presented in Table 3, the water pollution
in agricultural, industrial, domestic, and
miscellaneous sectors can be reduced 45, 88, 30, and 65
percent respectively. Table 3 presents the share of
each sector in annual water use, pollution load, and the percentage of pollution
reduction due to implementation of the proposed water pollution control projects.
However, as evidenced in Table 3, the pollution load is not completely related to
water use. For example, the domestic sector that
uses only 4 percent of the total water use discharges
26 percent of the total pollution load of the
system. Table 3 also shows the range of variation of
the estimated share of each sector in pollution load
due to uncertainty in estimation of water use, and quantitative and qualitative
characteristics of discharged wastewater. The estimated share for agricultural
and miscellaneous sectors is less
certain because of either insufficient or imprecise
data related to the assessment of pollution loads of
return flows, urban surface runoff, leakage from land
fills, underground storage tanks, and pipes which
are used for storage or transfer of oil and
related products. (Afkhami, 2005).
DISCUSSION
One of the most important phases of this
study has been the need to determine an accurate timetable and budget for
implementation of the projects. The projects with a higher
effectiveness have been prioritized and budgetary spending
has been provided. These priority projects will be executed during the first
few years of the water pollution reduction strategy. The share of
this allocation from the total budget is very high because of the high cost
of collection system. The allocated budgets to other sectors in this table
also show the amount needed for a one percent reduction of water pollution
in each sector.
As demonstrated below, the unit reductions in
urban and industrial projects are more than
agricultural and miscellaneous sectors. In a
suggested framework for approving, monitoring, and evaluation of Karun pollution
reduction projects, the Commission on Karun Environmental Protection will
be the major overseer for
these activities. The representative of Khuzestan Environmental Protection Office
will be the executive secretary of the commission. The commission will select
the members of
urban, agricultural and agro-industrial and
industrial committees. The main task of these
committees will be to review and tentatively approve
the suggested water pollution reduction projects
and their associated budget requirements
considering the overall framework for the master plan of
Karun pollution reduction. These recommendations
will then be passed to the Commission for final approval. The committees should
request details of design, required budget, and the implementation timetable
for different projects from all of
the involved organizations. Each committee should approve the above details based
on the compatibility of each project with the master plan for
Karun pollution reduction, available amount of budget
and time needed for implementation. Where budget restrictions affect the commencement
and delivery of a project, then the affected projects should
be prioritized keeping in mind the overall
framework and other "cause and effect" issues related to
the overall implementation of the master plan. For
this purpose, the projects are prioritized in this
study based on their effectiveness in Karun river
pollution reduction within the assessment limited
time framework. As an example, in the agriculture
and agro-industrial section that consumes 88.5% of
the total water and produce 48% of the
contamination, development of modern methods of irrigation
and increasing efficiency like treatment and reuse
of drainages that needs five years time and
100,000 million Rials, totally can reduce contamination
by 10.5% with spending 447000 million Rials. The WQMM using pollution mitigation
projects developed in this study was applied to the
Karun and Dez rivers because of their very poor
water quality. Pollution loads used in the model
were calculated using Arc-view. The project type
and cost of the projects in the river basin to simultaneously achieve the water
quality goals and pollution reduction cost optimization were calculated from
the model.
Nowdays, water quality management policy in Iran has
focused mainly on wastewater treatment capacity expansion through the construction
of new WWTPs. However, from an economic viewpoint this is extremely ineffective
and therefore it
is necessary to establish a systematic water
quality management plan that directly considers the
cost of pollution mitigation projects. In the WQMM
the results calculated using the QUAL2E model is directly used to check the water
quality goal. Accordingly, the WQMM has several advantages in that it can reflect
the non-linearity of
the mathematical water quality model, consider
several water quality parameters and find the exact
optimal solution to the cost optimization problem.
According to the above mentioned results, some
self-governing communities in the river basin
would need to invest heavily in river quality
management whilst other communities would contribute little
and it is appreciated that mediating the profits
and losses of the self-governing communities in
the river basin is very difficult. Nonetheless, it
is expected that the results of this study could
be beneficial for the water quality management
plan for comprehensive and cost-effective
management of the Karun and Dez rivers in both the short
and long term.
ACKNOWLEDGEMENTS
The valuable contribution of the managers
and engineers of Khuzestan Environmental
Protection Agency and Khuzestan Water and Power
Authority for providing data and site maps as well as
the technical assistance are hereby acknowledged.
REFERENCES
- Afkhami, M., (2003). Environmental Effects of Salinity
in the Karun Dez basin, Iran. Int. J. Arab. Water.
World. Beirut. Lebanon.
- Afkhami, M., Shariat, M., Jafarzadeh, N., Ghadiri, H.
and Nabizadeh, R., (2005) Quality and Operation
management plan of Karun and Dez Rivers at basic reaches.
Research Program of TSRC. IAU. Tehran. Iran.
- Bishop, A. B., Grenny, W. J., (1976). Coupled
optimization-simulation water quality model. J. Environ. Eng.
Division., ASCE., 92 (5): 1071-1086.
- Brown, L. e., Barnwell, J. R., (1987). The Enhanced
Stream Water Quality Models Qual2e and
QuaI2e-Uncas: Documentation and User Manual. EPN 600/3-87/007.
US Environmental Protection Agency, Athens. 15-16.
- Burn, D. H., (1989). Water-quality management
through combined simulation-optimization approach. J.
Environ. Eng., ASCE 115 (5): 1011-1024.
- Chen, H. W., Chang, N. B., (1998). Water pollution
control in the liver basin by fuzzy genetic algorithm-based
multi objective programming modeling. Water. Sci. Technol., 37 (3):
55-63.
- Cho, J. H., (2001). Development and Application of a
River Water Quality Management Model to Optimize the
Waste Load Abatement Cost by Genetic Algorithm,
Second Interim Report of the Interdisciplinary Research
Program of the KOSEF. Republic of Korea 2001 p. 56.
- Fujiwara, O., (1990). Preliminary optimal design model
for wastewater treatment plant. Journal of
Environmental Engineering. ASCE., 116 (I): 206-210.
- Fujiwara, O., Gnanendram, S. K., Ohgaki, S., (1987).
Chance constrained model for river water quality management.
J. Environ. Eng. ASCE., 113 (5): 1018-1031.
- Ghadiri, H., (1985). Reclamation of Salt Affected Soils
of Khuzestan and the Deterioration of Water quality of
Karun River. Shahid Chamran University. Ahvaz, Iran.
- Ghassemi, F., Jakeman, A. J. and Nix. H. A.,
(1995). Salinization of Land and Water Resources: Causes,
Extent, Management, and Case Studies. NSW University
Press. Sydney, Australia.
- Goldberg, D. E., (1989). Genetic Algorithms in
Search, Optimization and Machine Learning.
Addison-Wesley. Massachusetts, USA.
- Guidelines for drinking-water quality. (2004). Vol1,
3rd Ed. WHO. Geneva. Switzerland.
- Klemetson, S. L., Grenny, W. J. (1985). Dynamic
optimization of regional wastewater treatment systems.
J. Water. Pollut. Shar. Control. Federation., 57 (2): 128-134.
- Krenkel, P. A., Novotny, V., (1980). Water
Quality Management. Academic Press, Y. N. USA., 10003.
- KWPA., (2000)., An Assessment of Pollutants in
Karun River. A report prepared by the Water Quality
Assessment section, Khuzestan Water and Power Authority.
Ministry of Power. Ahvaz, Iran.
- KWPA., (2001). Salinization of Abadan Water. A report
prepared by the Division of Water utilization, Khuzestan Water
and Power Authority. Ministry of Energy. Ahvaz, Iran.
- Lee, C. C., Lin, S. D., (2000). Handbook of
Environmental Engineering Calculations, Mc Graw Hill, N. Y. USA.,
189-190.
- Liebman, J. C., Lynn, W. R., (1966). Optimal allocation
of stream dissolved oxygen, Water. Resources. Res., 2 (3): 581-591.
- Lohani, B. N., Thanh, N. C., (1979). Probabilistic
water quality control policies. J. Environ. Eng. Division.,
ASCE, 104 (4): 713-725.
- McNamara, J. R., (1976). Optimization model for
regional water quality management. Water. Resources. Res., 12 (2):
125-134.
- Novotny, V., Olem, H., (1994). Water Quality
Prevention, Identification, and Management of Diffuse Pollution.
Van Nostrand Reinhold. N. Y. USA.,603.
- Revelle, C. S., Loucks, D. P., Lynn, W. R., (1968).
Linear programming applied to water quality
management. Water. Resources. Res., 4 (I): 1-9.
- Shiva, V., (2002). Water wars: Privatization, Pollution
and Profit. South End Press.
- WCD., (2000). Dams and Development: A Framework
for Decision Making. A report of the World Commission
on Dams, Earth Scan Publication, London.
© 2007 Tehran University of Medical Sciences Publications
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