The Development of Saqqez City and its Effect on the Flooding the Saqqez River Basin

Flood is one of the which threats the cities, villages and farm land in our country the flood is a natural phenomenon that any river is talented to take that but what exist this phenomenon from its natural manner of makes that as a hazard is human interference in the nature. In the studied area some cases such as Saqqez urban development, interference to the rivers territory, destruction of the plant covers extension of the dry farm in sloped lands, designing and executing of the rivers crossways structures and etc caused to the increasing of the flooding to investigate the non- principle urban extension of fooling, the flood hydrograph using SCS method for the year of 1946 as the per- development period and 1996 (the most modern available map) as the post-development period has been designed and the calculations showed that the lag time of has in decreased from 1:56 min to 1:10 min, means by increasing the non- penetrable surfaces, the peak time of hydrograph has been decreased as 70 min so the flood go to it’s peak at a short time furthermore, the time getting to the peek discharge was 2:07 in 1946 while at 1996 had been 1:16 which is descending, then the flood peak get arrived 51 min earlier than before.