Geography Reference
In-Depth Information
The last step, which is important but often underestimated or omitted in a
program, is synthesis, compilation, presentation and interpretation of
enormous chemical data in a convenient manner for visual inspection (Freeze
and Cherry, 1979; Sara and Gibbons, 1991). On completion of the programme,
recommendations should be communicated to relevant water authorities for
water management, water pollution control, and eventually the adjustment or
modification of monitoring activities.
4.
T
OOLS FOR
W
ATER
Q
UALITY
A
NALYSIS
Several conventional tools for the graphical analysis of water quality are
described in standard textbooks on groundwater hydrology or hydrogeology
(Freeze and Cherry, 1979; Karanth, 1987; Sara and Gibbons, 1991). Recently,
the need for application of modern approaches and tools such as multivariate
statistical techniques (e.g., principal component analysis, hierarchical cluster
analysis, discriminant analysis and correspondence analysis), and remote
sensing and GIS techniques have been emphasized for the efficient analysis of
water quality (e.g., Jha et al., 2007; Steube et al., 2009). The state-of-the-art
review of tools and techniques for the interpretation of water quality can be
found in Machiwal and Jha (2010) wherein available tools and techniques
(conventional as well as modern) for analyzing water quality are classified into
four major groups: (i) graphical, (ii) statistical, (iii) remote sensing (RS),
geographic information system (GIS) and geostatistical, and (iv) modelling
techniques.
5.
GIS-B
ASED
A
SSESSMENT OF
W
ATER
Q
UALITY
V
ARIABILITY
Extensive literature search made by the authors of this chapter revealed
that most studies dealing with GIS applications for evaluating water quality
are focused on subsurface water compared to that on surface water.
This is most likely due to the relatively easy availability of large number
of point groundwater samples through wells (hand pump, open well, tubewell,
etc.).
However, sampling of surface waterbodies requires some mechanism
(e.g., boat) to reach different points in the waterbody.
