Analisa Kapasitas Drainase terhadap Banjir di Perumnas Mandala Medan

Abstract

Problem of water pond which occurred over the urban in Medan indicate that the water volume which come into drainage exeed the normal capacities from drainage and there are other factors cousing to dcrease the capacities of drainage. One of matter causing increase charge the surface current is precipitation intensity. Calculation of discharge with the rasional method use 3 primary factors, they are maximum rainfall intensity, wide of area, and run off coefficient. Maximum intensity from daily precipitation data calculated by using Log Pearson Tipe III method, used plan method Log Pearson Tipe III distribution, that aims to get the price of peak flood discharge with certain return period (Q10). The results and calculations is known that the amount of existing drainage discharge (Qext), the area aroung kecamatan Percut Sei Tuan edge magnitude smaller than the flood peak discharge (Qplan). Thus it can be deduced that the exsisting drainage system is unable to accommodate peak flood discharge. Thus surface current drainage exeed existing (Qext)the area around Rajawali street 7,235541 m3/second, where as smaller than the flood peak discharge (Qplan) the area around Rajawali Street 18,22488 m3/second to overcome the problem of stagnant water/flood in the vicinity of around Rajawali street Mandala, through some effort in to overcome that : Normalize the channel and leeve repairs in the main channel and enlarging the exsisting dimension of the channel