MIYUN RESERVOIR
An overview of the lake
Photo: Chinese Research Academy of Environmental Sciences.
A. LOCATION
- Beijing, P.R. China.
- 40:13-40:48N, 116:40-117:30E; 75 m above sea level.
B. DESCRIPTION
Miyun Reservoir, located 100 km northeast of Beijing City, is a mountain valley reservoir. It was built in September,1960, and is the largest reservoir in Beijing area. Two main rivers, Chaohe and Baihe, flow into Miyun Reservoir. The catchment is about 15,788 km2, consists of mountains and piedmonts and lacks large industrial enterprises. Sediments and nutrients from agricultural, pastoral and forestry lands that enter the reservoir with overland flow make the main pollution sources.
The initial purpose of building Miyun Reservoir was flood control, irrigation and fishery, but it has become more and more important as a main drinking water storage for Beijing area. The water quality is therefore of great importance.
Recently, the nutrient concentration and the number of phytoplankton in the Reservoir are constantly rising to arrest the attention of Beijing municipality. A project for keeping the water clean is being put into effect (Q).
C. PHYSICAL DIMENSIONS (Q)
| Surface area [km2] | 188 |
| Volume [km3] | 0.4375 |
| Maximum depth [m] | 43.5 |
| Catchment area [km2] | 15,788 |
D. PHYSIOGRAPHIC FEATURES (Q)
D1 GEOGRAPHICAL
- Number of outflowing rivers and channels (name)
2 (Chaobaihe R. and a canal).
D2 CLIMATIC
- Climatic data at Miyun Station, 1980-1983
| Jan | Feb | Mar | Apr | May | Jun |
Jul | Aug | Sep | Oct | Nov | Dec | Ann. |
|---|
| Precipitation [mm] | 1 | 5 | 7 | 27 | 28 | 95 | 124 |
162 | 43 | 19 | 6 | 3 | 520 |
- Number of hours of bright sunshine: 2,862 hr yr-1.
- Solar radiation: 15.5 MJ m-2 day-1.
- Water temperature [deg C]
| Lake centre, 1985 |
| Depth [m] | Jan | Feb | Mar | Apr | May | Jun |
Jul | Aug | Sep | Oct | Nov | Dec |
|---|
| 0.5*1 | - | - | - | 10.0 | 19.5 | 22.8 |
26.0 | 26.5 | 21.1 | 18.2 | 9.4 | - |
| 1.5 | - | - | - | - | 19.0 | - |
26.0 | - | - | 18.2 | - | - |
| 3.0 | - | - | - | - | 17.5 | - |
26.0 | - | - | 18.1 | - | - |
| 5.0 | - | - | - | - | 17.0 | - |
26.0 | - | - | 18.0 | - | - |
| 9.5 | - | - | - | - | 15.9 | - |
26.0 | - | - | 17.9 | - | - |
| 16*2 | - | - | - | - | - | - |
- | - | - | 16.6 | - | - |
*1 Surface. *2 Bottom.
- Freezing period: December-March.
E. LAKE WATER QUALITY (Q)
E1 TRANSPARENCY [m]
| Lake centre, 1985 |
| Depth [m] | Jan | Feb | Mar | Apr | May | Jun |
Jul | Aug | Sep | Oct | Nov | Dec |
|---|
| - | - | - | - | 1.25 | - |
1.72 | - | - | 2.58 | - | - |
E2 pH
| Lake centre, 1985-1986 |
| Depth [m] | Jan | Feb | Mar | Apr | May | Jun |
Jul | Aug | Sep | Oct | Nov | Dec |
|---|
| 0.5 | - | - | - | 8.2 | 8.2 | 8.3 |
8.2 | 8.5 | 8.3 | 8.2 | 8.2 | - |
| 1.5 | - | - | - | - | 8.34 | - |
- | - | - | - | - | - |
| 3.0 | - | - | - | - | 8.1 | - |
- | - | - | - | - | - |
| 5.0 | - | - | - | - | 7.65 | - |
- | - | - | - | - | - |
| 7.5 | - | - | - | - | 7.33 | - |
- | - | - | - | - | - |
| 10.0 | - | - | - | - | 7.15 | - |
7.9 | - | - | - | - | - |
| 15.0 | - | - | - | - | - | - |
8.0 | - | - | - | - | - |
E3 SS [mg l-1]
| Lake centre, 1986 |
| Depth [m] | Jan | Feb | Mar | Apr | May | Jun |
Jul | Aug | Sep | Oct | Nov | Dec |
|---|
| 0.5 | - | - | - | - | 4.5 | - |
- | - | - | - | - | - |
| 1.5 | - | - | - | - | - | - |
- | - | - | - | - | - |
| 3.0 | - | - | - | - | - | - |
2.8 | - | - | - | - | - |
| 5.0 | - | - | - | - | - | - |
4.0 | - | - | - | - | - |
| 7.5 | - | - | - | - | - | - |
- | - | - | - | - | - |
| 10.0 | - | - | - | - | - | - |
2.0 | - | - | - | - | - |
E4 DO [mg l-1]
| Lake centre, 1986 |
| Depth [m] | Jan | Feb | Mar | Apr | May | Jun |
Jul | Aug | Sep | Oct | Nov | Dec |
|---|
| 0.5 | - | - | - | - | 10.8 | - |
7.7 | - | - | - | - | - |
| 1.5 | - | - | - | - | 10.5 | - |
7.1 | - | - | - | - | - |
| 3.0 | - | - | - | - | 10.9 | - |
6.9 | - | - | - | - | - |
| 5.0 | - | - | - | - | 10.7 | - |
7.0 | - | - | - | - | - |
| 7.5 | - | - | - | - | 8.6 | - |
6.3 | - | - | - | - | - |
| 10.0 | - | - | - | - | 9.3 | - |
6.2 | - | - | - | - | - |
| 15.0 | - | - | - | - | - | - |
6.5 | - | - | - | - | - |
E5 COD [mg l-1]
Determined by KMnO4 method.
| Lake centre, 1985 |
| Depth [m] | Jan | Feb | Mar | Apr | May | Jun |
Jul | Aug | Sep | Oct | Nov | Dec |
|---|
| 0.5 | - | - | - | 1.88 | 2.51 | 2.63 |
2.82 | 2.82 | 3.10 | 2.58 | 2.85 | - |
E6 CHLOROPHYLL CONCENTRATION [micro l-1]
| Lake centre, 1986 |
| Depth [m] | Jan | Feb | Mar | Apr | May | Jun |
Jul | Aug | Sep | Oct | Nov | Dec |
|---|
| 0.5 | - | - | - | - | 2.77 | - |
4.14 | - | - | - | - | - |
| 1.5 | - | - | - | - | 2.82 | - |
5.41 | - | - | - | - | - |
| 3.0 | - | - | - | - | 3.10 | - |
6.00 | - | - | - | - | - |
| 5.0 | - | - | - | - | 3.33 | - |
5.71 | - | - | - | - | - |
| 7.5 | - | - | - | - | 3.20 | - |
5.36 | - | - | - | - | - |
| 10.0 | - | - | - | - | 2.92 | - |
4.65 | - | - | - | - | - |
| 15.0 | - | - | - | - | - | - |
5.09 | - | - | - | - | - |
E7 NITROGEN CONCENTRATION
| Lake centre, 1986 |
| Depth [m] | Jan | Feb | Mar | Apr | May | Jun |
Jul | Aug | Sep | Oct | Nov | Dec |
|---|
| 0.5 | - | - | - | - | 0.11 | - |
0.06 | - | - | 0.05 | - | - |
| 3.0 | - | - | - | - | - | - |
0.06 | - | - | 0.07 | - | - |
| 16.0 | - | - | - | - | - | - |
0.16 | - | - | 0.05 | - | - |
E8 PHOSPHORUS CONCENTRATION
| Lake centre, 1986 |
| Depth [m] | Jan | Feb | Mar | Apr | May | Jun |
Jul | Aug | Sep | Oct | Nov | Dec |
|---|
| 0.5 | - | - | - | - | 0.025 | - |
0.022 | - | - | - | - | - | |
| 1.5 | - | - | - | - | 0.013 | - |
0.028 | - | - | - | - | - |
| 3.0 | - | - | - | - | 0.011 | - |
0.027 | - | - | - | - | - |
| 5.0 | - | - | - | - | 0.025 | - |
0.030 | - | - | - | - | - |
| 7.5 | - | - | - | - | 0.008 | - |
0.028 | - | - | - | - | - |
| 10.0 | - | - | - | - | 0.012 | - |
0.029 | - | - | - | - | - |
| 15.0 | - | - | - | - | - | - |
0.038 | - | - | - | - | - |
F. BIOLOGICAL FEATURES (Q)
F1 FLORA
- Phytoplankton
Spring: Cyclotella, Bimuclearia. Summer and autumn: Cyclotella, Scenedesmus.
F2 FAUNA
- Zooplankton: Conochilus, Keratella cochlearis, Polyarthra trigla.
- Benthos: Oligochaeta.
- Fish: Hypophthalmichthys molitris, Aristichthys nobilis.
F5 FISHERY PRODUCTS
- Annual fish catch [metric tons]
1980: 1,360.5.
G. SOCIO-ECONOMIC CONDITIONS (Q)
G1 LAND USE IN THE CATCHMENT AREA
| 1984 |
| Area [km2] | [%] |
|---|
| Natural landscape | |
| Woody vegetation | 419.535 | 27.7 |
| Herbaceous vegetation | 871.327 | 57.6 |
| Agricultural land | |
| Crop field | 114.216 | 7.5 |
| Residential area | 82.012 | 5.4 |
| Others | 26.361 | 1.7 |
| Total | 1,513.451 | 100.0 |
- Main kinds of crops: Maize, wheat.
- Levels of fertilizer application on crop fields: Light.
- Trends of change in land use in recent years: It is planned to increase
forest area.
G3 POPULATION IN THE CATCHMENT AREA
| Population | Population density [km-2] | Major cities (population) | |
|---|
| Urban | None | - | None |
| Rural | 130,000 | 8.2 |
| Total | 130,000 | 8.2 |
H. LAKE UTILIZATION (Q)
H1 LAKE UTILIZATION
Sources of water, fisheries.
H2 THE LAKE AS WATER RESOURCE: No information.
I. DETERIORATION OF LAKE ENVIRONMENTS AND HAZARDS (Q)
I1 ENHANCED SILTATION
- Extent of damage: Not serious.
I2 TOXIC CONTAMINATION
I3 EUTROPHICATION
Though nitrogen, phosphorus and COD contents of the lake water are low, the
population densities of plankton and benthic invertebrates have increased as
compared with those in 1981, indicating a trend toward eutrophication. To
counter this trend, the establishment of industrial factories in the catchment
area as well as swimming and other surface recreations in the lake is
prohibited.
J. WASTEWATER TREATMENTS (Q)
J1 GENERATION OF POLLUTANTS IN THE CATCHMENT AREA
b) No sources of significant pollution.
J2 SANITARY FACILITIES AND SEWERAGE: No treatment system.
K. IMPROVEMENT WORKS IN THE LAKE (Q)
No information.
L. DEVELOPMENT PLANS (Q)
Since Miyun Reservoir will be one of the most important water sources for
Beijing City, fishery may be allowed with certain limitation as long as it
causes no harm to water quality. Water recreations are all forbidden. In the
catchment area, water and soil conservation practices are encouraged.
M. LEGISLATIVE AND INSTITUTIONAL MEASURES FOR UPGRADING LAKE ENVIRONMENTS (Q)
M2 INSTITUTIONAL MEASURES
- Miyun Environmental Monitoring Station, Miyun County (mission : monitoring and control of water quality and restoration of the environment)
- Miyun Reservoir Management Division, Miyun County (mission: monitoring of water quantity and control of water uses)
M3 RESEARCH INSTITUTES ENGAGED IN THE LAKE ENVIRONMENT STUDIES
- Chinese Research Academy of Environmental Sciences, Beijing
- Beijing Environmental Monitoring Station
N. SOURCES OF DATA
- Questionnaire filled by Prof. Liu Hongliang, Chinese Research Academy of Environmental Sciences, Beijing.
