Floods Hazard in Jazan Region, South West of Saudi Arabia: A Geomorphological Perspective

Abstract

Floods are usually considered to be one of the most important environmental issue in Jazan region. A Flood can be defined as a temporary but hazardous overflow of water which contains many solid substances, causing an increase in the level of water at the drainage basins and the valley, and is usually characterized by its unpredictable occurrence, high speed of its overflow and the simultaneous but sudden decrease in its amount of water. In the present study, the geological and typographical features of Jazan region together with the distribution of the rainfall have been studied for the purpose of demonstrating their effects on the occurrence of floods in this region and the effects of these floods on its ecology. In order to achieve this goal, the main features of the drainage basins in the region have been carefully studied by a means of exhibiting their geomorphometric characteristics and the variations of their places and how these factors are interrelated to (and with some effects on) the runoff channels of the floods. The present study also discusses the effects of climate changes on the hydrologic features of the drainage basins and how the interrelationship between the morophmetric and hyrologic features has an effect on the occurrence of the flood. In the present study, drainage basins have been classified according to the extent of their danger (high - moderate - low). In addition to determining the places in which groundwater can be found, the valleys in the region have also been classified in the present study according to the probability of flood occurrence in each of them (low possibility - moderate possibility - high possibility). The present study also discusses the problems inherited from the floods and their effects on the infrastructure of the region, and how the misconducts and misbehavior of the people may also contribute to the augmentation of flood hazard. The study then concludes by proposing and suggesting some of the possible means that might contribute in the reduction of flood hazard in the region.