• Topography
According to the local topography, the landfill of waste relies on natural gullies.
A gravity-type trapezoidal sandstone dam is built on cemented sand foundation
within 20 m from the mouth of the gully. The dam is made of sand and gravel that
are compacted into layers. The height is 15 m. The width and length are 5 m and
10 m respectively at the top, and 73 and 40 m at the bottom. The upstream slope is
1:2.0 and the downstream slope 1:2.5. The earthworks used for the dam amount to
4.3 Â 10
4 m
3 .
• Climatic characteristics
Haixi Prefecture is located in western Qinghai Province, with most of its areas in
the Qaidam Basin, and controlled by typical plateau continental climate. The unique
climate with unclear seasons is characterized by long sunshine hours, strong solar
radiation, large temperature difference between day and night, frequent drought and
wind, and little precipitation. The mean annual temperature registers 4 °C and the
annual precipitation averages 177 mm, with about 90% concentrated in May to
September. In short, the study area enjoys typical plateau continental climate.
With sufficient sunshine, the solar energy resources are plentiful. The prevailing
wind direction during the year is northwest. The proposed landfill sits in the gully
7 km from the northern town, which crosses the town’s dominant wind direction. It
has a small scale considering sound diffusion conditions created by frequent and
strong winds.
• Water table and geological information
The landforms of Haixi Prefecture mainly include the Qaidam Basin surrounded by
the Kunlun Mountains, Altyn-Tagh Mountains and Qilian Mountains and the
northern plateau of the Tanggula Mountains.
With an average elevation of about 3000 m, the Qaidam Basin is higher in the
north and east and lower in the middle and northwest. The lowest point of the
Qaidam Basin is 2675 m above the sea level, located in the Dabson and Hobson
Lakes near Golmud City. From the edge to the center, the landforms in the basin are
mountains, hills, Gobi, plains and lakes. There are more than 100 rivers and 90
lakes, of which the largest lake is Chaerhan Salt Lake.
It is from Geladandong, the main peak of the Tanggula Mountains in the
southern margin of the prefecture, that the Yangtze River originates, while the
Tanggula Pass is an important gateway to Tibet.
• Hydrogeology
The sub-basin of the Qaidam Basin where the landfill sits is surrounded by bedrock
mountainous areas and classified into macroscopically closed tectonic basin. Thick
and loose sand and gravel of the Quaternary period have been deposited. Especially
the gravel layer and silty gravel layer of the middle and upper Pleistocene periods
provide sound media and space for groundwater endowment. In the northern part,
the strata consist of the Upper Ordovician, Upper Carboniferous and Jurassic
5.2 Northwest China
169
According to the local topography, the landfill of waste relies on natural gullies.
A gravity-type trapezoidal sandstone dam is built on cemented sand foundation
within 20 m from the mouth of the gully. The dam is made of sand and gravel that
are compacted into layers. The height is 15 m. The width and length are 5 m and
10 m respectively at the top, and 73 and 40 m at the bottom. The upstream slope is
1:2.0 and the downstream slope 1:2.5. The earthworks used for the dam amount to
4.3 Â 10
4 m
3 .
• Climatic characteristics
Haixi Prefecture is located in western Qinghai Province, with most of its areas in
the Qaidam Basin, and controlled by typical plateau continental climate. The unique
climate with unclear seasons is characterized by long sunshine hours, strong solar
radiation, large temperature difference between day and night, frequent drought and
wind, and little precipitation. The mean annual temperature registers 4 °C and the
annual precipitation averages 177 mm, with about 90% concentrated in May to
September. In short, the study area enjoys typical plateau continental climate.
With sufficient sunshine, the solar energy resources are plentiful. The prevailing
wind direction during the year is northwest. The proposed landfill sits in the gully
7 km from the northern town, which crosses the town’s dominant wind direction. It
has a small scale considering sound diffusion conditions created by frequent and
strong winds.
• Water table and geological information
The landforms of Haixi Prefecture mainly include the Qaidam Basin surrounded by
the Kunlun Mountains, Altyn-Tagh Mountains and Qilian Mountains and the
northern plateau of the Tanggula Mountains.
With an average elevation of about 3000 m, the Qaidam Basin is higher in the
north and east and lower in the middle and northwest. The lowest point of the
Qaidam Basin is 2675 m above the sea level, located in the Dabson and Hobson
Lakes near Golmud City. From the edge to the center, the landforms in the basin are
mountains, hills, Gobi, plains and lakes. There are more than 100 rivers and 90
lakes, of which the largest lake is Chaerhan Salt Lake.
It is from Geladandong, the main peak of the Tanggula Mountains in the
southern margin of the prefecture, that the Yangtze River originates, while the
Tanggula Pass is an important gateway to Tibet.
• Hydrogeology
The sub-basin of the Qaidam Basin where the landfill sits is surrounded by bedrock
mountainous areas and classified into macroscopically closed tectonic basin. Thick
and loose sand and gravel of the Quaternary period have been deposited. Especially
the gravel layer and silty gravel layer of the middle and upper Pleistocene periods
provide sound media and space for groundwater endowment. In the northern part,
the strata consist of the Upper Ordovician, Upper Carboniferous and Jurassic
5.2 Northwest China
169