Data-driven modelling became popular tools following the creation of data bases for water resources engineering. One of the outcomes of the data driven modelling was the use of decision tree algorithm, a technique of data mining. Data mining is a process of searching the patterns in data using computer programs and drawing estimations from large amounts of data. For the decision tree, data are compiled and rules are written using the "if-conditional" method, starting from the roots and ending with the leaves of the tree.