An economic approach to establish design capacities for storm drams in the Indus Plain, West Pakistan.

Abstract

Most drainage systems established to cope with heavy monsoon rains in the Indus plain of W. Pakistan have too low a capacity. A method of calculating their economic capacity is proposed. Its application to the Lahore area indicated that a capacity around 0.5 1/ha./sec., resulting in a mean annual crop loss of 3.3 per cent., would be economically justified at the present level of crop management. Bases of the calculations are: probabilities of 24- and 48-hour rainfalls exceeding certain values, US data on runoff, data on peak floods in the Punjab, the assumptions that crops will not be harmed by inundation during five days and that mean annual losses without drainage would be 25 per cent. costs of systems with various capacities, and crop yields and returns. T. A. (Abstract retrieved from CAB Abstracts by CABI’s permission)