Scenario Trend Analysis on Water Balance in Fangshan

Scenario Trend Analysis on Water Balance in Fangshan
a
ZHU Qina YE Shuigena,* LI Fengb
College of Water Conservancy and Civil Engineering, China Agricultural University, Beijing, 100083,
P. R. of China
b
Fangshan Water Affairs Bureau, Beijing, 102488, P. R. of China
[email protected]
Abstract
Water resources shortage in Fangshan is very severely. This paper suggests a water balance
countermeasure through analyzing the supply and demand of water in Fangshan to ensure the
sustainable utilization of Haihe river basin water resources. It gives scenario trend analysis of social
economic development from the viewpoint of the sustainable development. It analyzes and calculates
the demand of water quantity for social development and environment based on the analysis of the
driving factors and restrictive factors of water demand. By analyzing the potential of water resources
tapping and saving, it proposes some basic and propulsion countermeasures to realize the water balance.
Key words Fangshan, water balance, scenario trend analysis
1 Background
Fangshan is located in the south-western of Beijing. There are 22 counties and the total area is 2019
sq.km. The northwest part of Fangshan is mountain, and the southeast part is plain. River system of
Fangshan includes Daqinghe watershed and Yongdinghe watershed. Daqinghe watershed can be divided
into Dashihe, Jumahe and Xiaoqinghe. Fangshan is one of the districts which have the maximum density
of population in Beijing. The total population of Fangshan was 0.903 million in 2004. The annual gross
domestic product was 142.39 hundreds of million yuan. Among them the primary industry produces
12.31 hundreds of million, the secondary industry produces 68.05 hundreds of million, and the rest of
GDP contributes to the tertiary industry which is 62.04 hundreds of million.
1.1 Surface Runoff
Lying in warm temperate semi humid climate zone, the weather is hot and wet in summer and chill and
dry in winter in Fangshan. The temperature distribution here is uneven. The annual average temperature
is 11 . The number of the northwest part which covers by mountain is from 9 to 11 , whereas the
southeast plain is from 11 to 12 .
According to the Fangshan Water Resources Assessment, multi-year average precipitation of the district
is 587.6mm, which for the mountain part is 599.2mm, for the plain part is 567.7mm. Wet year (P=25%)
precipitation of the district is 687.0mm. Normal year (P=50%) precipitation is 571.3mm. Partial dry year
(P=75%) precipitation is 459.1mm. Dry year (P=95%) precipitation is 338.0mm (Table 1.1). From the
table, it shows that the maximum annual precipitation is the one of 1956, which was 1085.0mm, and the
minimum one is in 1965, which was 315.8mm. Rainfall was mainly concentrated from June to August,
which account for 85% of the total year precipitation.
℃
Area
mountain
plain
total
*1
℃
℃
℃
℃
Table 1.1 Analysis of Frequency of Precipitation in Fangshan
Wet
Multi-year
Partial dry
Normal
year
average
year
year
Cv
Cs
Series
20%
precipitation
75%
50%
(mm)
(mm)
(mm)
(mm)
1956-2004
599.2
0.283
0.566
735.4
583.4
471.3
1956-2004
567.7
0.316
0.632
710.5
548.6
432.0
1956-2004
587.6
0.29
0.58
724.2
571.3
459.1
1956-2000
595.1
0.29
0.58
734.3
578.3
464.0
Corresponding author. Telephone Number: 13621384030
Email Address: [email protected]
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Dry year
95%
(mm)
350.0
308.2
338.0
340.8
According to the gross rainfall account, the multi-year average precipitation is 11.88 hundreds of million
cubic meters, which contains 795 millions in mountain areas and 393 millions in plain areas.
Multi-year (1956-2004) average quantity of surface runoff is 204.634 million steres. Wet year (P=20%)
number is 311.042 hundred million steres. The number of normal year (P=50%) is 131.011 hundred
million steres. The number of partial dry year (P=75%) is 692.15 hundred million steres. The number of
dry year (P=95%) is 429.78 hundred million steres. (Table 1.2)
area
（
mountain
plain
total
Table 1.2 Analysis of Frequency of Surface Water Resources in Fangshan
Normal
Muti-year
Partial dry
Wet
year
average
year
year
series
Cv
Cs
precipitation
50% 104
75%
20%
104m3
104 m3
(104 m3)
m3
1956-2004
15175.2
1.0
2.5
23066.4
9715.6
5132.8
1956-2004
5288.2
0.84
2.1
7909.3
3866.4
2180.2
1956-2004
20463.4
1.0
2.5
31104.2
13101.1
6921.5
1956-2000
21054.0
1.0
2.5
32196.0
13561.0
7164.0
（
）
）
（
Dry year
95%
104m3
） （
）
3187.2
1223.5
4297.8
4449.0
1.2 Groundwater
The mountain bedrock groundwater of Fangshan District is located in tertiary weathering conglomerate
pore water. Cretaceous, the Jurassic and Carboniferous conglomerate, sandstone and shale and volcanic
fissure water. Ordovician and Cambrian and Sinian fractured limestone karst water and Yanshan granite
and granodiorite weathering fracture water. However, karst distribution is uneven, the nature of
water-rich water, the levels and the water amount are also big differences.
According to the assessment of water resources, the combination of mountain groundwater, determined
that the available exploitation of underground water is the amount for 26.13 million m3 in Fangshan
Mountain. The average amount of water available for many years for exploitation is 249.92 million m3.
The average years of groundwater exploitation amount is 281 million m3, amounted to excessive
extraction is 31 million m3, the utilization rate reached 112%. 2004 ultra-realistic water production
19.38 m3.
1.3 The total water resources
The total water available is the local surface water available resources with the volume of shallow
groundwater resources exploitation, deducting the amount of duplication between the two. In the area of
duplication between the amounts of surface area is mainly the utilization part of plain water supply of
shallow groundwater. We can draw the results: the total available water resources in the region for
multi-year average is 327.708 million m3, it was 433.308 m3 in wet years, 284.644 million m3 in usual
years, 210.708 million m3 in much lower, 151.138 million m3 in dry year.
Table 1.3 Water resources in different levels of scale (million m3)
Partial dry
Multi-year
Wet year
Usual year
year
Areas
average
20%
50%
75%
mountainous
1020.06
1475.36
739.83
460.80
plain
2502.31
3153.61
2369.14
1857.51
repeated amount
245.29
302.32
238.49
191.65
Total
3277.08
4333.08
2846.44
2107.08
Source: “Fangshan District of Beijing water resources planning” 2007.3
Dry year
95%
309.67
1348.46
141.10
1511.38
2 Analysis on water balance
2.1 Available water supply
The available water supply in Fangshan is mainly precipitation and outside the region inflows, the
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inflows mainly come from the surface water of Juma River and Xiaoqing River. The mean precipitation
amount of 2002, 2003 and 2004 is respectively 481.2 mm, 508.4 mm, 642.3mm. According to the
integrated planning of water resources, the inflows of Juma River in 2002, 2003 and 2004 is respectively
52 million m3, 61 million m3, 138 million m3. Xiaoqing River’s inflow is negligible.
2.2 Water consumption
According to the Fangshan ET data provided by the project Office, calculated the value of Fangshan ET
integrated in 2002, 2002 is 646.2 mm, 702.0 mm in 2003, 718.3mm in 2004; The regional surface water
outflow (Juma River) is respectively 42 million m3, 36 million m3, 154 million m3. A lateral water
outflow over multi-year average is 59.84 million m3. Fangshan District, the groundwater level has
changed 0.51 m, 0.21m,-0.55m respectively in 2002,2003 and 2004, corresponding to the amount of
water resources is respectively 51 million m3, 21 million m3, -56 million m3, if taken by degree of
supplying water µ 0.05 calculation.
2.3 Analysis of the water supply and demand balance
According to the above data, we can analyze the water balance (Table 2.1).
Item
Table 2 The water balance analysis sheet of Fangshan
Unit
2002
Area
Precipitation
2003
2004
2014
2014
2014
mm
481.2
508.4
642.3
P
108 m3
9.69
10.24
12.94
ET
mm
646.2
702
718.3
108 m
13.01
14.14
14.47
m
-0.51
-0.21
0.55
0.25
0.25
0.25
108 m3
-0.89
-0.37
0.96
3
0.52
＋
0.61
0.42 0.60
＋
1.38
3
0.36 0.60
1.54 0.60
3
10.21
10.85
14.32
3
13.14
14.73
17.57
Area
2
km
P
ET
3
ET
△H
Groundwater level
Changes
degree of supplying
water
Reserve variables
Inflows
Outflows
Total supply amount
Total consumption
µ
µ
△HGW
RIN
108 m
ROUT
P+RIN
ET+ROUT+µ
△HGW
108 m
108 m
108 m
＋
Table 2.1 shows, water consumption is far greater than supply, in 2004 a difference of 325 million m3,
the main reason can be: (1) The calculated ET is larger, also showing a certain degree of error, (2) When
calculating the supply amount, there is no considering of the spring flow and recharge effect of the deep
pressure.
3 Social and Economic Development Trends
3.1 Population Growth Trend
According to the “Fangshan Economic and Social Statistical Yearbook” from 1989 to 2004, Agricultural
population proportion decreased year by year. It decreased to 56.04% whereas it was 69.96% in 1989.
Natural increasing rate per year of resident population in Fangshan is 1.7‰. The rate of urbanization
rose from 42.1% in 2001 to53.3% in 2004.
According to “Fangshan New Town Plan” in 2005, rate of urbanization in 2010 will be 70%, and rate of
population growth will be 7.5‰, which means the population will reach to 0.944 million in 2010,
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including 0.661 millions of citizens and 0.283 millions of rural people. Rate of urbanization in 2020 will
be 79%. Rate of population growth will be 22.6‰, which means the population will reach to 1.18
million in 2010, including 0.932 millions of citizens and 0.248 millions of rural people.(Table 3.1)
Table 3.1 Trend of Population Growth
Country
Year
4
Population(10 ind)
（ ）
2004
42.2
rate %
46.67
2010
2020
28.3
24.8
30.00
21.00
City
4
Population(10 ind)
（ ）
48.2
rate %
53.33
66.1
93.2
70.00
79.00
（
）
Total 104ind
90.3
94.4
118.0
3.2 Economic Development Trend
According to the “Fangshan Economic and Social Statistical Yearbook” from 1991 to 2004, GDP of
Fangshan in 1991 was 14.7 hundred million yuan, while the number increased to 142.4 hundred million
yuan. The rate of the annual growth is 17.6%. Among them the agricultural product was from 4.3
hundred million yuan to 12.3 hundred million in 1991, the annual rate of which is 7.8%. The secondary
industry product increased to 68 hundred million yuan from 7.9 hundred million yuan in 1991, the
annual rate of which is 12.8%. Building industry product increased to 29.5 hundred million yuan from
0.8 hundred million yuan in 1991, the annual rate of which is 29.5%. The tertiary industry product
increased to 62.0 hundred million yuan from 2.5 hundred million yuan in 1991, the annual rate of which
is 25.8%. Industry structure optimized constantly. The ratio of these three industries becomes to be
8.6:47.8:43.6, which was 29.2:53.8:17.0 in 1991.
According to “Fangshan New Town Plan” and “Beijing Fangshan Integrated Water Resources and
Environment Management Plan”, it can be predicted that in 2010, GDP will grow up to 385.1 hundred
millon yuan by 9.6% per year, the ratio of these three industry will be 4:65:31, among which the primary
industry increases by 9.6% per year, the secondary industry increases by 9.1% per year, and the tertiary
industry increases by 11.5% per year. In 2020, GDP will grow up to 866.6 hundred millon yuan by 8.4%
per year, the ratio of these three industry will be 3:52:45, among which the primary industry increases
by 5.4% or more per year, the secondary industry increases by 6.0% or more per year, and the tertiary
industry increases by 12.5% or more per year.(Table 3.2, 3.3)
Year
（
）
Population（10 ）
4
Total value 10 yuan
4
Mean value(yuan)
Year
Industry
（ ）
（
）
Total（10 yuan）
Proportion %
Increase
108yuan
8
Table 3.2 GDP Prediction in Fangshan
2000
2010
843387
2020
3851520
8665920
80.1
94.4
118
10529
40800
73440
Table 3.3 Industry Structure Prediction in Fangshan
2010
2020
primary
secondary
tertiary
primary
secondary
industry
industry
industry
industry
industry
4
65
31
3
52
15.4
250.3
119.4
385.15
26.0
450.6
tertiary
industry
45
390.0
866.59
3.3 Trend Analysis on Water Resources Demand
Sustainable utilization of water resources is one of the basic conditions of market economic and social
sustainable development. It sets newer and higher requirements to water resources for regional
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sustainable development. It follows two aspects including the driving factors and restrictive factors to
analyze water demand trend in Fangshan.
3.3.1 Driving Factors
Population growth, economic development and demand of ecological environment protection are three
primary factors of driving demand of water resources. Considering water using targets, users can be
divided into domestic water user, production water user and environment water user. In next decades,
population of Fangshan will increase continuously, rate of urbanization will get further increased, and
water consumption per capita will increase further as well. Industry will get sustained and rapid
development. Under the premise of limited damping of industry water-using, water consumption in
industry will increase rapidly. As to agricultural water-using, because of the increasing irrigation area,
agriculture water consumption will keep growing before 2030 even water use efficiency get
improvement. As the demand of building the ecological civilization of China, it becomes increasingly
urgent to protect the ecological environment of Fangshan, which means the environment water-using
will be continuously increasing in the next decades.
3.3.2 Restrictive Factors
The increasing demand of water resources is not endless. On the contrary, it limits by total volume of
water resources, ability of development and use of water resources, level of water management and
water market demands. Total volume of water resources in Fangshan, hydraulic engineering
construction and level of management and finance condition obviously restrict the scale of water
demand in Fangshan to some degree. As the system of farming develops, the new irrigation system is
established and implemented, the agricultural management level gets improvement, the efficient of
industry water-using increases, propaganda force of water saving increases, as well as the construction
of the South-to-North Water Diversion Project and Zhangfang Emergency Water Supply Project, and
reclaimed water reuse, the increasing demand of water resources in the district could be partially
ameliorated in some extent.
4 Scenario setting and scheme analysis
4.1 Scenario setting
According to the Fangshan water resources and water environment problems which include shortage of
water resources, serious overexploitation of groundwater(overexploitation area reached 182 sq.km in
Chengguan, Xiacun, Liangxiang and Shilou region)and poor surface water quality, the scenario are set.
4.1.1 Consider irrigation quota management under the water-saving irrigation measures
In 2004, the total irrigation area is 448100 mus in Fangshan District, of which water-saving irrigation
area is 301100 mus. Irrigation methods include canal lining, low pressure pipeline, micro irrigation,
canal seepage control, micro jet, drop irrigation and so on.
4.1.2 Consider agricultural planting frame adjustment
Reduce dry food and open-air vegetable fields which water consumption are large, and increase forest
land, facility agriculture, dry fruit which water consumption are small. Set up two structures by the
status quo unchanged and agricultural planting frame optimization.
4.1.3 Consider overexploitation of groundwater
One method is to reduce groundwater overexploitation by 10% each year (1.9million m3), in 10 years
groundwater will achieve exploration and replenishment balance. The other is to strengthen the
management of self-equipped wells in overexploitation area which will stop overexploitation of
groundwater by 2010.
4.1.4 Consider Pollutants Reduction
One is the rapid reduction which will reduce 50% by 2010 and achieve to standards by 2020.The other
is gradual reduction which will reduce 25% by 2010, 80% by 2020, and achieve to standards by 2030.
4.2 Scheme Analysis
According to scenario setting, 16 programs are combined (Table 3-20). Boundary conditions are as
followed: control 30 million m3 net output, use rainfall from 1980 to 2004, and natural vegetation
242
remains unchanged.
scenarios
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
Water saving
Medium water-saving
Highly water-saving
Medium water-saving
Highly water-saving
Medium water-saving
Highly water-saving
Medium water-saving
Highly water-saving
Medium water-saving
Highly water-saving
Medium water-saving
Highly water-saving
Medium water-saving
Highly water-saving
Medium water-saving
Highly water-saving
Table 4.1 scenario programs
cropping pattern
Groundwater Over exploitation
Current condition
Reduce step by step
Current condition
Reduce step by step
Optimization
Reduce step by step
Optimization
Reduce step by step
Current condition
Strengthen reducing
Current condition
Strengthen reducing
Optimization
Strengthen reducing
Optimization
Strengthen reducing
Current condition
Reduce step by step
Current condition
Reduce step by step
Optimization
Reduce step by step
Optimization
Reduce step by step
Current condition
Strengthen reducing
Current condition
Strengthen reducing
Optimization
Strengthen reducing
Optimization
Strengthen reducing
Pollution control
Reduce rapidly
Reduce rapidly
Reduce rapidly
Reduce rapidly
Reduce rapidly
Reduce rapidly
Reduce rapidly
Reduce rapidly
Reduce gradually
Reduce gradually
Reduce gradually
Reduce gradually
Reduce gradually
Reduce gradually
Reduce gradually
Reduce gradually
According to water balance principle, analyze various scenarios programs.
4.2.1 Comparative analysis between agricultural planting frame adjustment and irrigation quota
management
Compared with Water-saving status (moderate) and a high degree of water-saving, excluding planting
frame optimization, water-saving amount will be respective 6.52million m3, 5.9 million m3, 6.12 million
m3 till 2010, 2020, 2030. If planting frame optimization is considered, they will be respective
6.74million m3, 6.33 million m3, and 7.02 million m3.
Figure 4.1 Agriculture reduce the amount of groundwater exploitation and programs to reduce the amount of
groundwater
4.2.2 Scenario analysis of groundwater overexploitation
Close up the self-equipped wells in overexploitation area gradually. According to the current
overexploitation amount is 3100 m3, stop overexploitation in 2015, that is to say 50% of
overexploitation amount will be reduced in 2010 and overexploitation will stop in 2015. The other
method is to strengthen the management of self-equipped wells in overexploitation area which will stop
overexploitation of groundwater by 2010.
According to the above analysis, 85% of water consumption that optimization program of agricultural
planting frame adjustment and irrigation quota management can reduce is from Groundwater.
Agriculture can reduce the exploitation of groundwater as shown in Figure 4.2
243
Figure 4.2 Agriculture reduce the amount of groundwater exploitation and programs to reduce the amount of
groundwater
As can be seen from the chart, strengthening reduction of groundwater overexploitation in agriculture
alone can not meet the requirements in 2010 and 2015 no matter which programs. With highly
water-saving and planting frame optimization,2.5 million m3 need to be reduced in 2015 in addition to
agriculture according to the gradually reduction program,8.53 million m3 in 2010 and 2.5 million m3 in
2015 according to the forcibly reduction program. As a result, gradually closing up the self-equipped
wells of other industries is imperative.
5 Conclusions
The imbalance between supply and demand of water resource in Fangshan is conspicuous. This situation
can be partly solved by water-saving and reclaiming the wasted water. It’s very important to study water
resources and environment carrying capacity well, strengthen the protection of water resources and
environment, save water, and develop and use water resources efficiently. It has actual and far-reaching
meaning to support the social and economic development of Fangshan with limited water resources.
References
[1] Demand of Water Resources in Sanjiang Plain for Sustainable Development, Yao Jingfu,Wang
Zhongbo, Xiao Jianmin, Heilongjiang Science and Technology of Water Conservancy, 2005(6),
61~63 (in Chinese)
[2] Discuss on Balance of Supply and Demand of Water Resources in Haihe Basin in Shandong, Zheng
Yongjie, Qian Xiuhong, Xu Hua, Theory and Practice on Water Environment Management Based on
Harmonious Relationship Between Human Beings and Environment,20050900,199~222(in
Chinese).
[3] Integrated Water Resources and Environment Management Plan in Fangshan, (in Chinese).
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