Abstract
This paper reports on the classification for the types of the water pressure (P) versus the flow rate (Q) curves (P-Q curves) that obtained by the borehole permeability tests, and the consideration on the causes for these types.
In these tests, the relation between the flow rate (Q) and the water pressure (P) is expressed in general equation as
Q=KPα
therefore, the types of the Q curves can be classified by the value of α, as follows
α=1-the normal type (N type)
α>1-the increase type (I type)
α<1-the decrease type (D type)
The causes for these types and subdivision can be so considered as follows
N type (α=1) -by the laminar flow
I type (α>1)
I-a type-by the percolation
I-b type-by the progressive increase of the permeable cross section.
I-c type-by the piping
D type (α<1)
D-a type-by the closed fissure or the beeing impervious
D-b type-by the limit of apparatus
D-c type-by the turbulent flow
