Regional Evaluation of Hydrometric Monitoring Stations through Using Entropy Theory

Proper design and operation of monitoring systems for water resources management is one of themost important issues of water quality and quantity and accuracy and adequacy of data. The properevaluation of these data has a determining role in the correctand consistent decisions in the areacovered by the system. Therefore, determining proper distribution and number of monitoringnetwork stations and evaluation of theadequacy of existing network stations are needed to eliminateunnecessary stations and as a result decreasing costs of data productionthat are importantchallenges in the future. In this study, a new approach, based on this theoryof regional value ofhydrometric stations in Bakhtegan- Maharlu watershed has been investigated. In this case, usingdiscrete entropy theory, existing limitations in theprevious studies were removed and consideringthe indices of total information sent by the station S(i), total information received by the stationR(i) and total net information by the station N(i), the monitoring network has been assessed. Theresults of sensitivity analysis showed that values of entropy indices are sensitive to variation ofdata-classification interval. The calculated values of R(i) and S(i)are equivalent completely andeach station received as much information as it sent to other stations. In addition, with regard toacceptable results by Storeajse relation, using this equation to determine the appropriate number ofclasses is recommended. The obtained results showed that 4 out of 14 hydrometric Stations are incritical conditions and it is recommendedthat they should be removed from the network.