A well-developed drainage network was carved in the study area in a hard calcretized and gypcretized gravelly sand of the Dibdibba Formation (Al-Rukham slope) in pluvial episodes in the post-pleistocene age, and is re...A well-developed drainage network was carved in the study area in a hard calcretized and gypcretized gravelly sand of the Dibdibba Formation (Al-Rukham slope) in pluvial episodes in the post-pleistocene age, and is referred to be paleo-drainage due to the current witnessed aridity. This study aims to investigate the geomorphologic, morphometric, and stratigraphic characteristics of the paleo-drainage system and its role in recharging shallow aquifers. Morphometric analysis was accomplished using GIS and remote sensing techniques. Six vertical pit holes were dug across the area to investigate the stratigraphy and recharging capacity. The drainage system is composed of 10 closely spaced, subparallel, dendritic, elongated, and variant-sloped drainage basins with highest stream order of 5. Water flows NE from Al-Rukham ridge’s crest (60 m a.m.s.l.) downstream in Khor Al-Subiyah coastal flat. The bed rock’s hard resistant nature lowered its infiltration and recharging capacity to the shallow aquifer, whereas the coarse-grained wadi fills deposits increased infiltration capacity of the surface sediments, but the water percolation chance is limited as it eventually directed seaward by the same-directed general topography resulting in limiting potential recharge to the shallow aquifers. This is suggested to oppose the salt water intrusion and thus enhance fresh water quality.展开更多
文摘A well-developed drainage network was carved in the study area in a hard calcretized and gypcretized gravelly sand of the Dibdibba Formation (Al-Rukham slope) in pluvial episodes in the post-pleistocene age, and is referred to be paleo-drainage due to the current witnessed aridity. This study aims to investigate the geomorphologic, morphometric, and stratigraphic characteristics of the paleo-drainage system and its role in recharging shallow aquifers. Morphometric analysis was accomplished using GIS and remote sensing techniques. Six vertical pit holes were dug across the area to investigate the stratigraphy and recharging capacity. The drainage system is composed of 10 closely spaced, subparallel, dendritic, elongated, and variant-sloped drainage basins with highest stream order of 5. Water flows NE from Al-Rukham ridge’s crest (60 m a.m.s.l.) downstream in Khor Al-Subiyah coastal flat. The bed rock’s hard resistant nature lowered its infiltration and recharging capacity to the shallow aquifer, whereas the coarse-grained wadi fills deposits increased infiltration capacity of the surface sediments, but the water percolation chance is limited as it eventually directed seaward by the same-directed general topography resulting in limiting potential recharge to the shallow aquifers. This is suggested to oppose the salt water intrusion and thus enhance fresh water quality.
