type of groundwater is mainly distributed along the faults in extremely different
quantities. The single-spring outflow is generally 0.1–1 L/s; and the salinity of the
HCO 3 Á Cl–Ca type water approaches 0.5 g/L.
Bedrock fissure water
Bedrock fissure water is mainly distributed in the northern middle and high
mountainous area. It can be divided into layered rock fissure water and massive
rock fissure water according to aqueous media.
Layered rock fissure water is distributed in the northern foothills of the study
area. The aquifer is composed of the Upper Carboniferous Zhongwu Nongshan
Group sandstone. Since weathering fissures and tectonic fissures have been formed,
the groundwater receives recharge from precipitation. Due to the constraints of
topography, meteorology and other factors, coupled with steep terrain, the
groundwater quantity is small and generally, the single-spring outflow is less than
0.1 L/s. The salinity registers 0.47 g/L of the HCO 3 Á Cl–Na Á Ca type water.
Massive rock fissure water is distributed in the northern middle and high
mountainous areas of the study area. The aquifer is comprised of granitic gneiss and
granite of the Upper Dakendaban Group. Though tectonic fissures have been created, but due to topographical and meteorological factors and aqueous media, the
fissure water is unevenly distributed with large quantity difference. Springs emerge
sporadically only in sulcus at higher altitudes at a rate of 0.2–0.5 L/s per spring. The
salinity of the groundwater is 0.17 g/L.
Frozen layer water
Frozen layer water is distributed in the northern bedrock mountainous areas at an
altitude of more than 3800 m. According to aqueous media, it can be divided into
the water in the upper frozen layer of loose rock and the water in the upper frozen
layer of bedrock (the lower frozen layer is not evaluated due to data unavailability).
(a) Water in the upper frozen layer of loose rock
It is mainly distributed in the valleys in the northern middle and high mountainous
areas. The aquifer is comprised of glacial and slope gravel and sandstone and
recharged by ice and snow meltwater. Constrained by topography, the aquifer is
relatively thin and has poor water yield property. The groundwater is exposed
mostly as falling springs of HCO 3 Á Cl–Na type, with a salinity of less than 0.5 g/L.
(b) Water in the upper frozen layer of bedrock
It is distributed in the northern middle and high mountainous areas. The aquifer is
comprised of Ordovician quartz schist, gravel-bearing sandstone, metamorphic
sandstone, gneiss and phyllite. The groundwater is mainly recharged by precipitation
and snow and ice meltwater as tectonic fissures and weathering fissures are relatively
developed. Affected by climate, the groundwater generally exists in solid state in
winter and as liquid runoff in summer. Water in the upper frozen layer is relatively
plentiful and widely exposed as falling springs with an outflow of 0.1–1 L/s per single
spring. The salinity of the HCO 3 Á Cl–Na type water is less than 0.5 g/L.
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161
quantities. The single-spring outflow is generally 0.1–1 L/s; and the salinity of the
HCO 3 Á Cl–Ca type water approaches 0.5 g/L.
Bedrock fissure water
Bedrock fissure water is mainly distributed in the northern middle and high
mountainous area. It can be divided into layered rock fissure water and massive
rock fissure water according to aqueous media.
Layered rock fissure water is distributed in the northern foothills of the study
area. The aquifer is composed of the Upper Carboniferous Zhongwu Nongshan
Group sandstone. Since weathering fissures and tectonic fissures have been formed,
the groundwater receives recharge from precipitation. Due to the constraints of
topography, meteorology and other factors, coupled with steep terrain, the
groundwater quantity is small and generally, the single-spring outflow is less than
0.1 L/s. The salinity registers 0.47 g/L of the HCO 3 Á Cl–Na Á Ca type water.
Massive rock fissure water is distributed in the northern middle and high
mountainous areas of the study area. The aquifer is comprised of granitic gneiss and
granite of the Upper Dakendaban Group. Though tectonic fissures have been created, but due to topographical and meteorological factors and aqueous media, the
fissure water is unevenly distributed with large quantity difference. Springs emerge
sporadically only in sulcus at higher altitudes at a rate of 0.2–0.5 L/s per spring. The
salinity of the groundwater is 0.17 g/L.
Frozen layer water
Frozen layer water is distributed in the northern bedrock mountainous areas at an
altitude of more than 3800 m. According to aqueous media, it can be divided into
the water in the upper frozen layer of loose rock and the water in the upper frozen
layer of bedrock (the lower frozen layer is not evaluated due to data unavailability).
(a) Water in the upper frozen layer of loose rock
It is mainly distributed in the valleys in the northern middle and high mountainous
areas. The aquifer is comprised of glacial and slope gravel and sandstone and
recharged by ice and snow meltwater. Constrained by topography, the aquifer is
relatively thin and has poor water yield property. The groundwater is exposed
mostly as falling springs of HCO 3 Á Cl–Na type, with a salinity of less than 0.5 g/L.
(b) Water in the upper frozen layer of bedrock
It is distributed in the northern middle and high mountainous areas. The aquifer is
comprised of Ordovician quartz schist, gravel-bearing sandstone, metamorphic
sandstone, gneiss and phyllite. The groundwater is mainly recharged by precipitation
and snow and ice meltwater as tectonic fissures and weathering fissures are relatively
developed. Affected by climate, the groundwater generally exists in solid state in
winter and as liquid runoff in summer. Water in the upper frozen layer is relatively
plentiful and widely exposed as falling springs with an outflow of 0.1–1 L/s per single
spring. The salinity of the HCO 3 Á Cl–Na type water is less than 0.5 g/L.
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161