Estimating Ground Water Aquifer Transmissivity Using well Specific Capacity Data For Tazerbo Wellfield, SE - Libya

Abstract

Since the wells specific capacity data useful for estimating aquifers transmissivity, should be used to increase the number of ground water aquifer transmissivity estimations. In this study, an investigation of transmissivity (T) estimating using specific capacity (Sc) in the aquifer region of Tazerbo wellfield - SE Libya was established. The main procedure for transmissivity estimation in this study was: first, using analytical equation derived from Theis nonequilibrium formula solved by AQTESOLV software. Second, evaluation the existing empirical equations for sandstone aquifers transmissivity. Finally a new empirical relationship between transmissivity and specific capacity for Tazerbo wellfield aquifer was proposed and compared with other existing relationships. At this point the comparison between transmissivity values done by statistical analysis like efficiency coefficient (E) and mean absolute error (MAPE%).Moreover, this study shows that ( ) producing results close to the values obtained from step pumping test with (E=0.92) and (MAPE=5.01%), and provide an average value of transmissivity within the range of 95CI%.Transmissivity obtained from the selected relationships display that they are not effective for the study area aquifer, except Sandra (2016) equation provides a closed transmissivity values to the calculated one with (E=0.83) and (MAPE=7.05%).