دور التغايرية المناخية في نشوء الفيضانات النهرية غير المرئية: حالة المجال الحضري لمدينة قصبة تادلة (حوض أم الربيع- المغرب)

The topic of flood risks in light of the variability of the climate that Morocco has witnessed and is witnessing has become more important than ever in the field studies of urban and peri-urban centers, which are penetrated by valleys and reefs in Morocco, which often result in catastrophic losses at the

material, human and environmental levels. These floods often occur as aresult of climatic variability and in response to strong and concentrated rainfall in time and place, with weak infrastructure, which constitutes a major challenge to the population, and complicates management and preparation operations.

      In Morocco and very precisely in the city of Kasba Tadla, the wadi of Oum Er-Rbia crosses the urban area and divides the city into two parts. All the urban neighborhoods that surround the river, disturb the quality of water through discharges from domestic activities, which in most cases end up in rivers, through a direct pipe. If the role of the urban sewerage system is to discharge wastewater to the treatment plants. It also helps to preserve the quality of groundwater and surface water by avoiding direct discharges of wastewater into the stream.

     During the high-water period, the flows of the Oum Er-Rbia stream do not only cause floods and direct overflows. They often cause many other types of urban flooding, with sewer backups in all of the houses along the river.

     Through this paper, we want to show the importance of these anthropogenic urban hydrological phenomena, by understanding these floods of sewer backups related to the increase of flows of the Oum Er-Rbia stream. Try to understand their behaviors, map the spatial extent of these floods and finally analyze their impacts on the urban environment of the city of Kasba Tadla.