(b) Tectonic fissure type
The tectonic fissure type is characterized by perpendicular tectonic fissures below
land surface, which differ little in scale and maturity degree and have flat sections.
Groundwater generally exists in the tectonic fissures connected the groundwater. In
view of similar structure, the tectonic fissure type can be generalized into monolithologic vadose zone, but with stronger permeability, the value should be greater
and the value range should be narrowed (Fig. 3.11).
(4) Karst water regions
(a) Bare karst type
Under the dissolution effect, erosional fissures form below land surface in the
vadose zone, but they vary in form and scale of sections. In the vadose zone of bare
karst type, groundwater generally exists in erosional fissures connected to
groundwater. In view of similar structure, the bare karst type can be generalized into
monolithologic vadose zone, but with stronger permeability, the value should be
greater and the value range should be narrowed (Fig. 3.12).
(b) Covered karst type
The covered karst type consists of low-permeablity clay layer at the top and
high-permeability erosional fissure media at the bottom. Groundwater is stored in
the erosional fissures. In view of similar structure, the covered karst type can be
Fig. 3.11 Vadose zone
structure—tectonic fissure
type
Fig. 3.12 Vadose zone
structure—bare karst type
3.2 Method of Groundwater Pollution Source Intensity Rating …
53
The tectonic fissure type is characterized by perpendicular tectonic fissures below
land surface, which differ little in scale and maturity degree and have flat sections.
Groundwater generally exists in the tectonic fissures connected the groundwater. In
view of similar structure, the tectonic fissure type can be generalized into monolithologic vadose zone, but with stronger permeability, the value should be greater
and the value range should be narrowed (Fig. 3.11).
(4) Karst water regions
(a) Bare karst type
Under the dissolution effect, erosional fissures form below land surface in the
vadose zone, but they vary in form and scale of sections. In the vadose zone of bare
karst type, groundwater generally exists in erosional fissures connected to
groundwater. In view of similar structure, the bare karst type can be generalized into
monolithologic vadose zone, but with stronger permeability, the value should be
greater and the value range should be narrowed (Fig. 3.12).
(b) Covered karst type
The covered karst type consists of low-permeablity clay layer at the top and
high-permeability erosional fissure media at the bottom. Groundwater is stored in
the erosional fissures. In view of similar structure, the covered karst type can be
Fig. 3.11 Vadose zone
structure—tectonic fissure
type
Fig. 3.12 Vadose zone
structure—bare karst type
3.2 Method of Groundwater Pollution Source Intensity Rating …
53