Spatial Heterogeneity of Hydraulic Conductivity in Green Infrastructure Due to Presence of Wilted and Live Grass: A Field Study

Abstract

Spatial variation of hydraulic conductivity governs the performance of green infrastructure. Previous studies show that, hydraulic conductivity of vegetated soil may vary by 400% due to presence of vegetation. However, spatial variation of hydraulic of wilted grass in the vicinity of a tree was rarely studied previously. The objective of this study is to investigate spatial variation of hydraulic conductivity of wilted mix grass in the vicinity of a tree. Field monitoring was conducted for two months in the site consisting live grass and wilted grass. The selected site consists of (i) mix grass cover under tree shade during entire daylight period, (ii) mix grass cover under tree shade during 3–4 h of daylight period, (iii) mix grass cover under light during entire daylight period and (iv) soil surface covered by mix grass and shredded leaves. Hydraulic conductivity was measured at 150 locations in the selected site using mini disk infiltrometer. Hydraulic conductivity of wilted and live grass near the tree stem (i.e., under tree shade during entire daylight period) was found to be lower than that away from tree stem. In addition, hydraulic conductivity of wilted and live grass under light during entire daylight period was found to be higher than that under shade for 3–4 h of daylight period. Furthermore, hydraulic conductivity of wilted grass was found to be lower than that of live grass in case of all the selected categories. The obtained results help to analyze the performance of green infrastructure accurately.