ground water is recharged by surface water, while in the dry season, surface water is
recharged by groundwater.
Fissure water of bedrock is widely distributed in and around the project site. The
rock is mainly rhyolitic crystal tufflava, and there is no obvious dividing line
between the recharge area and the discharge area. Generally, the higher area is the
recharge area, while the lower area is the discharge area. Groundwater flows are
mostly runoff along the slope and are discharged to the gully and a certain stream in
the form of spring. The hydraulic connection between groundwater and surface
water is greatly affected by season. In the wet season, groundwater is recharged by
surface water in a certain stream and gullies, while in the dry season, a certain
stream and gullies are recharged by groundwater.
③ Range of groundwater level
During the wet season in July 2013 and the dry season in November 2013, the
groundwater level of the tested wells in the project site was measured respectively.
The groundwater in the project site varies greatly, with the depth of groundwater
water generally being 4.00–22.27 m in the wet season, and 6.0–24.0 m in the dry
season. The depth of groundwater table is shallow in gullies and large on hillsides
and hilltops. The annual variation of water level is generally between 0.5 and
8.5 m, in which the larger variation of water level is distributed in gullies with low
terrain. For example, the annual variation of water level of K2 monitoring well in
front of the dam in the reservoir area is 8.5 m, the depth of groundwater table is
4.00 m in the wet season and 12.5 m in the dry season. Generally, the smaller
annual variation of water level is 0.5–1.73 m, which is mainly distributed in the
places where the depth of groundwater table is larger, such as hillsides. It shows
that the hydraulic connection between the groundwater in the area and the surface
water in a certain stream and gullies is greatly affected by the season, groundwater
is recharged by surface water in a certain stream and gullies in the wet season, while
surface water is recharged by groundwater in the dry season. See Table 5.70 for the
list of range measurements of groundwater at the site in the wet and dry seasons.
④ Development characteristics of structural fissures in the site area
I. Structure
The lithology at the site is mainly dacitic tufflava in the second member of Nanyuan
Formation (J3n2) and light flesh pink granite porphyry, and the surface layer is
mostly covered by eluvial, diluvial and weathered layers. The eluvial and diluvial
layers are relatively thin and generally less than 0.5 m.
Faults and dikes are relatively developed in the area, mainly in NEE, NNW and
EW directions. Most faults are tensional and compressional, and fissures are relatively developed along the fault plane on its both sides. Most fissures are slightly
tensional and have certain water conductivity.
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recharged by groundwater.
Fissure water of bedrock is widely distributed in and around the project site. The
rock is mainly rhyolitic crystal tufflava, and there is no obvious dividing line
between the recharge area and the discharge area. Generally, the higher area is the
recharge area, while the lower area is the discharge area. Groundwater flows are
mostly runoff along the slope and are discharged to the gully and a certain stream in
the form of spring. The hydraulic connection between groundwater and surface
water is greatly affected by season. In the wet season, groundwater is recharged by
surface water in a certain stream and gullies, while in the dry season, a certain
stream and gullies are recharged by groundwater.
③ Range of groundwater level
During the wet season in July 2013 and the dry season in November 2013, the
groundwater level of the tested wells in the project site was measured respectively.
The groundwater in the project site varies greatly, with the depth of groundwater
water generally being 4.00–22.27 m in the wet season, and 6.0–24.0 m in the dry
season. The depth of groundwater table is shallow in gullies and large on hillsides
and hilltops. The annual variation of water level is generally between 0.5 and
8.5 m, in which the larger variation of water level is distributed in gullies with low
terrain. For example, the annual variation of water level of K2 monitoring well in
front of the dam in the reservoir area is 8.5 m, the depth of groundwater table is
4.00 m in the wet season and 12.5 m in the dry season. Generally, the smaller
annual variation of water level is 0.5–1.73 m, which is mainly distributed in the
places where the depth of groundwater table is larger, such as hillsides. It shows
that the hydraulic connection between the groundwater in the area and the surface
water in a certain stream and gullies is greatly affected by the season, groundwater
is recharged by surface water in a certain stream and gullies in the wet season, while
surface water is recharged by groundwater in the dry season. See Table 5.70 for the
list of range measurements of groundwater at the site in the wet and dry seasons.
④ Development characteristics of structural fissures in the site area
I. Structure
The lithology at the site is mainly dacitic tufflava in the second member of Nanyuan
Formation (J3n2) and light flesh pink granite porphyry, and the surface layer is
mostly covered by eluvial, diluvial and weathered layers. The eluvial and diluvial
layers are relatively thin and generally less than 0.5 m.
Faults and dikes are relatively developed in the area, mainly in NEE, NNW and
EW directions. Most faults are tensional and compressional, and fissures are relatively developed along the fault plane on its both sides. Most fissures are slightly
tensional and have certain water conductivity.
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