Hydromorphometric and flow characteristics of the
suggested dams basins in Ulaya Wadis,
Al Kharj
AlJuaidi, Farhan
Abstract
This study demonstrates the analysis of rainfall frequency and
hydromorphometric and flow characteristics for the suggested dam
basins in Ulaya wadis, mainly the Upper basins of Mawan and
AlAin in Al-Kharj province. Annual rainfall for the return period
between 2 to 100 years ranging as follows; 100.6 mm/y and 244
mm/y in Riyadh station, and between 98.1 mm/y and 246.6 mm/y
in the AlKharj station, and 57.4 mm/y and 208.4 mm/y in the Huta
station, and 72.3 mm/y and 178.6 mm/y in the Al-Hariq station and
finally between 74.9 mm/y and 254 mm/y in Wadi Hanifa station.
Morphometric analysis shows that the drainage basin area in wadi
Al-Ain is bigger than the area in Wadi Mawan by more than 77
km2. In Wadi Al-Ain basin, streams numbers are about 1111 with
total length of 728 km, the mean bifurcation ratio is around 4.18
and the drainage density is 2 km/km2. Whereas in Wadi Mawan
basin, streams numbers are about 2207 with total length of 785
km, the mean bifurcation ratio is around 4.84 and the drainage
density is 2.7 km/km2.
Flow characteristics indicate that maximum discharge peak in wadi
Al-Ain basin reaches 1310.4 m3/sec, the specific discharge peak is
3.59 m3/s/km2 and runoff volume is 120.8 .10 6 m3 with depth
reaches 333.4 mm. Whereas maximum discharge peak in wadi
Mawan basin reaches 1279.1 m3/sec, the specific discharge peak
is 4.45 m3/s/km2 and runoff volume is 116.9 .10 6 m3 with depth
reaches 407.1 mm.