2010 3rd International Conference on Biomedical Engineering and Informatics BMEI 2010 Application WASP Model on Validation of Reservoir-Drinking Water Source Protection Areas Delineatio
Trang 12010 3rd International Conference on Biomedical Engineering and Informatics (BMEI 2010)
Application WASP Model on Validation of Reservoir-Drinking Water
Source Protection Areas Delineation
Jianping Huang*1,2, Na Liu1, Mengyuan Wang1
1Environmental and Municipal Engineering Department
North China University of Water Resource and Electric Power
Zhengzhou, China
Kelu Yan2
2College of Chemical Engineering and Biotechnology
Donghua University Shanghai, China
Abstract—Applied the OTOXI module and EUTRO module of
WASP7.2 model to carrying out forecast analysis on attenuation
condition of the main water quality control factors within
second-level protection area which delineated by experience value, took
the reality water volume of 2007 and forecast water volume of
2010, 2020 as the validating condition, demonstrated the
rationality of the second-level protection area which delineated
by experience value method The results indicated that the
second-level protection area could satisfy industry and life water
request in 2007 and 2010, and could also satisfy the request of
living in 2020, the protection area delineation has been proved
reasonable Further obtained the allowable maximum taking
water volume of the protection area is 145 million m 3 /a through
the computation, it is suggested that the industry intake moves
when water volume which taken from the first-level and
second-level protection areas is bigger than the maximum volume, to
ensuring the quality and stability of the intake drinking water
Keywords-WASP7.2 model; reservoir-drinking water source;
delineating protection areas; validation
I INTRODUCTION Recent years the raises concerns about increased drinking
water wellhead pollution make people highly be focus on
safeguarding the public water supply The drinking water
wellhead protection plays a key role in terms of environmental
protection, socio-economic and safeguarding the public water
supply Many methods or approaches are being used to
delineate drinking water wellhead all over the word, but exact
prediction of a wellhead protection effort is difficult because
the amount of field work required for each method depends on
how much information is already available, the complexity of
the problem area, and the degree of accuracy desired by the
wellhead protection program [1,2,3] Drinking water wellhead
protection areas was re-delineated and approved work by the
State Council and State Environmental Protection
Administration (SEPA) in 2006 “Technical guidelines for
delineating source water protection areas” (HJ/T338-2007)
which was mandated in 2007 provided basis for drinking water
wellhead protection delineating Wellhead protection
delineating must be accurate and easy to carry out The
drinking water wellhead delineating combined actual
circumstance, especially for reservoir-drinking water source, is
faced with many challenges and needs further study
Nanwan Reservoir is located from 8.5km southwest to the
city of Xinyang, Henan Its drainage area is 1100km2 and total
Reservoir water volume is 16.3 billion m3 Nanwan Reservoir
is a Large-scale Reservoir which mainly combined by flood-protection, irrigation and so on At the same time it is the only drinking water wellhead of Xinyang A water quality model, WASP 7.2, was applied to simulate water quality results of drinking water wellhead delineated by experience value method, demonstrated the rationality of the protection area which delineated by experience value method The results of this division may provide a draw for the delineation of the reservoir-drinking water source and a more practical approach for the operation of reservoir
II INTRODUCTION OF WASP7.2 MODEL Water quality analysis simulation program (WASP) was developed by the EPA to simulate the water quality of rivers and lakes and so no WASP 7.2 model is the seventh improved version of WASP water quality model; it follows the law of mass conservation and adopts study of composition of variable water quality model [4] At the same time it considered dilute diffusion process, migration delivery process, physical transformation and biological metabolic processes, direct load
of pollutants, border load and so on WASP 7.2 is designed to permit easy substitution of user written routines into the program structure The model simulated and quantified relationship among convection, dispersion, point source pollution load, non-point sources pollution load and boundary exchange via time Based on flexible compartment modeling, WASP can be applied in one, two, or three dimensions of all waters: ponds, streams, lakes, reservoirs, rivers, estuarine, and coastal waters, and for the fate and transport of contaminants in surface waters [5,6] Three major submodules are contained in the WASP7.2 model: TOXI, EUTRO and HEAT The first is coupled with migration delivery process of traditional contamination (DO, BOD, eutrophication), the second is coupled with migration delivery process of toxic contamination (organic chemical component, metal, sedimentation), and the third is coupled with migration delivery process of heat [7]
Water quality analysis simulation program (WASP) is an effective, pragmatic and reliable water quality model which applied in and aboard
III VALIDATION STUDY OBJECT
It is determined that there was no attenuation of water quality between first-level protection area and quasi-protected area the basis for the analysis water quality goal of wellhead
*Corresponding author: huangjianping@ncwu.edu.cn
Trang 2protection areas The second-level protection area water quality
controlling factors reached the level of class Ⅲ in “Surface
Water Quality Standard” (GB3838-2002) and the first-level
protection area water quality controlling factors were as the
same [8], that is to say water quality attenuation from Ⅲ to Ⅱ
was completed in second-level protection area The radial
distance which was from the first-level protection area
boundary to the second-level protection area boundary should
longer than the distance of attenuation of pollutant
concentration from Ⅲ to Ⅱ (GB3838-2002) So delineating
second-level protection area of delineating wellhead protection
areas was the main important issue for water suppliers,
experience value method as validating model was adopted to
delineate second-level protection area
Applied OTOXI module of WASP7.2 model to simulating
the CODMn, the results showed that the degradation of the
CODMn was in accordance with the first-order reaction, and
applied simple nutrition dynamics of OTOXI module to
validate eutrophication of second-level protection area
IV MODELING OF VALIDATION
1) Simplification of grid: Based on the detail of real data
and availability of hydrologic data, water quality data, making
the volume of each grid similar as much as possible and
making concerned points locate in the center of grid The delineating drinking water wellhead protection was shown in
Fig.1 Specific steps are as follows:
a) Simplified of topographic map of Nanwan reservoir
second-level protection region water boundary;
b) Establish validation concerned points which is the
nearest radial distance from the first-level protection area boundary to the second-level protection area boundary There are four water intakes in Nanwan reservoir Three which located in the same enclosure in the Southeast of Dam were Tielu intake plant, Hudong intake plant and Huayu Power plant except one was located in the west of Dam The three closer intakes as one protection area was delineated by experience value method Then the first-level protection area involve two parts and the concerned points are A and B,
respectively (Fig.1);
c) Grid was delineated by combining the size of studying
region and the concerned points, the grid was about 608.19m
×501.74m;
d) A 20-segment model grid, a 20-segment node and a
30-segment channel were established for studying region When the eutrophication submodel ‘EUTRO’ was used for the water body analysis simulation program increased a bottom section under each grid which using for substances precipitation but without simulation
Trang 32) Hydrological condition: Throughout 1955-2005, lots of
data such as the average runoff, water level, water depth,
storage capacity were obtained Based on the above data,
hydrological condition of studying region was obtained by
combining topographic map
3) Dynamic source of flow movement and simplification of
Reservoir water flow, water diffusions which caused by water
volume change (intake water volume) of studying region was
the main dynamic source of movement and the main cause of
contamination migration delivery process Validation of
dynamic source of water flow movement is the main cause of
Nanwan Reservoir water flow movement and 15 flow
functions of WASP7.2 model were adopted to express water
flow
importing that did not have significant impact on water quality
of studying region by analysis and investigation Three
boundaries were selected as validation simulation model of
second-level protection area: one upstream boundary
(second-level protection area boundary) and two downstream
boundaries (two first-level protection boundaries) Water
depth of boundary, the width of water area and so on was
obtained from topographic map There was response relation
exist between water input and water intake
B Estalishment of water quality model
1) Water quality control factors: The main contaminations
of Nanwan Reservoir were TP, TN, NH3-N and CODMn
Effects of chlorophyll-a [9] on zooplankton were incorporated
into water quality analysis simulation program model, so as to
divide TN to NH3-N, NO3--N, organo-nitrogen and TP to
organo-phosphorus, inorganic phosphorus Chlorophyll-a,
NH3-N, NO3--N, organo-nitrogen, organo-phosphorus,
inorganic phosphorus and CODMn were selected as the main
water quality control factors
areas water quality requirements, initial concentration of
second-level protection area water quality controll factors
were the level of class Ⅱ (GB3838-2002), initial
concentration of water quality controlling factors of water
TABLE I T HE INITIAL CONCENTRATION OF STUDYING REGION
Parameters Initial concentration of
second-level protection area
Inlet concentration of second-level area
Chlorophyll a
Organo-nitrogen(mg/L) 0.133 0.266
NO 3--N(mg/L) 0.258 0.517
Organo-phosphorus
Inorganic
phosphorus (mg/L) 0.01766 0.0353
flow which from quasi-protected area to second-level protection area were the level of class Ⅲ (GB3838-2002)
Chlorophyll-a was the level of “Environmental quatity standards for surface water” (GHZB1-1999) on the condition
of without on formulation of GB3838-2002 and the level of classⅡ, Ⅲ was 4μg/L, 10μg/L, respectively
Based on the detail of many years monitoring data and relative information, in order to simulation more reasonable, the ratio of organo-nitrogen, NH3-N, NO3--N was 0.266:0.217:0.517, the ratio of organo-phosphorus, inorganic phosphorus was 0.294:0.706 The molecular formula of classic algae according to Redfield’s law is C106H263O110N16P, demonstrated that 1μg/L chlorophyll-a contributes 0.009μg/L phosphorus and 0.063μg/L nitrogen, a relatively small contribution The results showed that TP and TN concentration addition caused by chlorophyll-a can be ignored
The initial concentration of studying region was shown in Table 1
boundary condition was determined by water quality boundary condition of the second-level protection area boundary and the first-level protection area boundary which was the upstream boundary and downstream boundary of studying region, respectively That is to say, the upstream water quality boundary condition was the inlet concentration of the second-level protection area boundary and the down stream water quality boundary condition was the initial concentration of the second-level protection area boundary as shown in Table 1
4) Load condition: The pollution loading of studying
region was mainly caused by water which were flowed from second-level protection area border Based on this model, load
condition (kg/d) can be described as Eq (1):
Load condition=Water quality boundary condition
of upstream×Flow boundry condition (1)
TABLE II T HE PARAMETERS OF VALIDATION MODEL
Parameters Data
Degradation coefficient of COD Mn 0.0175d -1
Organ phosphorus mineralization rate at 20℃ 0.04 day -1
Nitrifying rate at 20℃ 0.026 day -1
Organic nitrogen mineralization rate at 20℃ 0.03 day -1
Half saturation constant of DIN 0.025 mg N/L Half saturation constant of inorganic phosphorus 0.001 mg P/L The largest growth rate of phytoplankton at 20℃ 2.0day -1
Phosphorus-carbon ratio in phytoplankton 0.025 Nitrogen-carbon ratio in phytoplankton 0.176
Light attenuation 0.017m 2 /mg chl.-a Extinction coefficient 0.45 m -1
Average illumination intensity 300 langleys/day Saturation light intensity for phytoplankton
growth 300 langleys/day Phytoplankton respiration at 20℃ 0.1day -1
Phytoplankton mortality 0.02 day -1
Phytoplankton sedimentation speed 1m/day Inorganic phosphorus sedimentation speed 0.03 m/day
Grazing rate 1.2L/mgC-day
Trang 4C Study on the main parameters
Degradation constant applied from inverse method by
laboratory simulation study simulated with conclusion of other
micro-pollution water area [10,11] Based on the actual
circumstances of Nanwan Reservoir [7,12], empirical data was
used as EUTRO module simulation parameters The nutrients
conservation test for related parameters was carried out The
simulation results showed that choosing model parameters
involved a certain degree of credibility Details of the main
parameters of module are summarized in Table 2
V STUDY AND CONCLUSION VALIDATION
According to analysis of taking water volume of Nanwan
Reservoir, took taking water volume of 2007, 2010 and 2020
as the validating condition as circumstances simulation
analysis
water volume of 2010, 2020 as the validating condition of
protection area delineating
Took the reality water supply amount of Nanwan
Reservoir of 2007(including drinking water and industry water)
and forecast total water amount of 2010, 2020 as flow
boundary condition, demonstrated the rationality of protection
area which delineated by experience value method
On condition of reality water volume of 2005 and
forecast water volume of 2010, the concentration of CODMn,
NH3-N, TN and TP of concerned points all reached the level
of class Ⅱ in “Surface Water Quality Standard”
(GB3838-2002) The second-level protection area which delineated by
experience value method has been proved reasonable
On condition of forecast water volume of 2020, the
CODMn, TN and TP of the section of concerned points will all
exceed the allowed range The results showed forecast life
water volume of 2020 is smaller than forecast water volume of
2020 It is suggested that separated the industry intake and the
drinking water intake and moved the industry intake from
second-level protection area The protection area which
delineated by experience value method could ensure the
quality and stability of the intake drinking water
protection area
The allowable maximum taking water volume of the
protection area is 145 million m3/a through a lot of trial
calculations, that is to say when water volume which taken
from the first-level and second-level protection area is bigger
than 145 million m3/a, the water quality of first-level
protection area boundary may worse than the level of class Ⅱ
even when the water quality of second-level protection area
boundary reached the level of class Ⅲ under the protection
area delineation
TABLE III W HEN ACHIEVING WATER QUALITY STABLE THE FORECAST
CONSISTENCE OF THE CONCERNED POINTS
COD Mn
(mg/L)
NH 3 -N (mg/L)
B 0.127 0.182 0.161
TN (mg/L)
A 0.387 0.46 0.525 0.5
B 0.368 0.449 0.509
TP (mg/L) A B 0.004 0.015 0.051 0.025 0.001 0.005 0.037
VI CONCLUSION
1) According to validating study, the results indicated that
the second-level protection area which delineated by experience value could satisfy industry and life water request
in 2005 and 2010, and could also satisfy the request of living
in 2020, the protection area delineation has been proved
reasonable;
2) The allowable maximum taking water volume of the
second-level protection area is 145 million m3/a, it is suggested that the industry intake moves when water volume which taken from the first-level and second-level protection area is bigger than the maximum volume, to ensuring the
quality and stability of the intake drinking water;
3) The use of WASP7.2 model in simulation of water
quality should base on a lot of parameters The following work
should enhance the monitoring work of reservoir and provide
available data for the model, making the model more suitable
to actual situation
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