A Corrected Time-Area Technique for One-dimensional Flow

Time-area method is one ofthe most widely applied techniques ofwatershed routing, andcan be potentially used as a distributed model. in this paper, afundamental flaw in the arrangementof subareas in the original time-area histogram is identified for one-dimensional flow. this isconducted on the basis ofcomparing time-area hydrograph with that ofthe kinematic wave theorem.accordingly, a revised time-area algorithm is developed as a substitute for the original time-area.it is proved that in the revised approach, subareas must be reversely arranged. it is also shown thatthe revised time-area hydrograph is in perfect agreement with the hydrograph derived by thekinematics wave theory.