TITLE:
SCS-CN and GIS-Based Approach for Estimating Runoff in Western Region of Saudi Arabia
AUTHORS:
Abed Alataway
KEYWORDS:
Runoff, SCS-CN, GIS, Remote Sensing
JOURNAL NAME:
Journal of Geoscience and Environment Protection,
Vol.11 No.3,
March
15,
2023
ABSTRACT: Designing reservoir operations, hydraulic structure, and soil erosion
management techniques all require an estimation of a potential runoff. Accurate
runoff in-formation is typically scarce in Saudi Arabia—a significant challenge for hydrologists.
Wadi-Rahjan catchment in Western Saudi Arabia has been taken as a case study to
determine the potential runoff estimates. The study integrates the soil
conservation service curve number (SCN-CN) technique, remote sensing (RS), and geographical information system (GIS). Critical parameters including the digital elevation model (DEM), land use/land
cover (LULC), hydrologic soil groups (HSGs), and rainfall data were also
employed. The curve number (CN), which shows the catchment’s reaction to a
storm was estimated based on LULC and HSG layers. The CN map obtained and rainfall
data were employed in the GIS-based SCS-CN model to develop the potential
runoff map. Based on the results of calculations, the study area is classified
into three HSGs, namely, B, C, D. Averagely, CN for a normal condition is 90
while wet and dry conditions are 97 and 80, respectively. Results obtained from
the SCS-CN method’s calculations reveal a yearly runoff result that varies from
194 mm to 295 mm. A higher percentage of runoff water (35%) in a runoff range
from 289 to 295 mm, followed by 24%, ranged 269 to 288 mm. An interesting
rainfall-runoff regression evaluation reveals a good 0.90 correlation. Other
watersheds in Saudi Arabia may use this method for planning and development.