Assessment of the Watershed Properties of Iyi-Abi Stream Forest in Asaba, Delta State, Nigeria (Published)
This study was conducted to assess the potential properties of Iyi-abi stream forest watershed in flood management of the Asaba metropolis. Three locations were mapped out at the tail-water (TW), midcourse (MC) and headwater (HW) axes of >150 stand/ha, < 150 stand/ha and approximately 150 stand/ha in the closed, high and low canopy cover of the watershed respectively. Twenty-one (21) soil samples were augered from 0-40cm depths at gridded intersection points within each location and then bulked in three (3) replicates for determination of water aggregate stability, hydraulic conductivity, particle and bulk densities, porosity, pH, CEC, P and N-levels. Data collected were subjected to ANOVA, significant means (p>0.05) separated with DMRT and coefficient of variation was used to estimate soil variability along the watershed. Results showed that particle density was HW > MC >TW (1.87±0.56 g/dm3) and bulk density was MC < TW (1.40±0.08 g/cm3) < HW. Mean water stable aggregates was TW (22.50) > MC (18.50) > HW (15.10) with the highest hydraulic conductivity (3.58±0.66 cm/hr), water dispersal energy (10.5 J/g), CEC (3.24 ± 0.33 meq/100g) and organic matter content at tail-water (TW). Thus, underpinned the efficiency of the watershed in tail-water axis as most significant in the flood control and therefore, the need to protect the stream forest from further attenuation by adoption into the urban forest landscape development scheme in the metropolis for eco-friendly environment.
Keywords: Forest litters, Soil aggregates, Watershed