Hydro-physical characterization of contrasting urban and natural soils in a semi-arid basin: Implications for water transfer in Bouskoura, Morocco

Abstract

Urbanization modifies soil conditions and may alter the partitioning of rainfall between surface run - off and subsurface water transfer, particularly in semi-arid environments. This study characterizes the hydro-physical properties of soils under contrasting land-use conditions in the Bouskoura Basin, Mo - rocco. Four site-specific soil samples representing dense urban, peri-urban, industrial, and natural forest environments were analyzed for particle-size distribution, natural water content, bulk and dry density, and Atterberg limits. Total porosity was estimated from dry density using an assumed particle density of 2650 kg m −3 . The results show clear differences in particle-size composition and measured hydro-physical properties among the investigated sites. The industrial sample contains the highest gravel frac - tion (25%), whereas the natural forest sample has the highest fine-particle fraction (48.2%). Dry density ranges from 1540 to 1671 kg m −3 , with the highest value occurring at the natural forest site. Natural wa - ter content ranges from 4.4% to 12.5%. These observations indicate contrasting soil conditions among the investigated land-use settings that may influence water storage and subsurface transfer. However, infiltration rate, hydraulic conductivity, and groundwater recharge were not directly measured; there - fore, hydrological implications are interpreted as potential effects rather than quantified processes. The study provides a site-specific hydro-physical baseline for future investigations of infiltration, runoff, and groundwater recharge in the rapidly urbanizing Bouskoura Basin.