3. Application of MATLAB Based Fuzzy Inference System
The methodology used in this model has been explained in six simple steps as shown in Figure 3. For illustration,
sustainability measure of the groundwater well located at Bana village with respect to domestic usage has been briefly explained. The same procedure has been applied for remaining groundwater wells. The main steps of the
process are as follows: (a) the membership grades for input variables (i.e. water quality parameters) have been
defined in MATLAB FIS framework, (b) the membership grades are also defined for the sustainability measure of
groundwater well, say at Bana for domestic purposes as the output variable. (c) Fuzzy inference rules are defined
using AND operator with the help of experts, (d) Normalized values of all water quality parameters have been
derived as shown in Table 1 and aggregation values have been evaluated under fuzzy inference rules to get the final
measure of sustainability of the well. Thus the sustainability measure of a well located at Bana for domestic
purposes is 0.644 which has been expressed as 64.4 %. It indicates that a well located at Bana demonstrates "good"
sustainability condition as can be seen from Figure 2. Similarly sustainability measures of all the wells have been
evaluated and classified with respect to both domestic and irrigation usages as shown in Tables 3 and 4.