Effect of highway greenbelt constrution on groundwater flow in a semi-arid region

Abstract

The highway greenbelt, vigorously promoted in arid and semi-arid areas, has obvious impacts on beautifying the environment, absorbing dust, reducing noise, and maintaining soil and water. Moreover, it affects the characteristics of how water resources are distributed and the regional groundwater cycle. The Hu-Bao highway greenbelt in the northern Tumochuan Plain served as an example in this study. Based on fully grasping the characteristics of the regional groundwater system, we used the 3S classification method and combine the relevant formulas, such as ET0, to calculate the evapotranspiration and water consumption of the green belt and quantitatively analyze the impact of highway greenbelt construction on the regional groundwater cycle. The results indicated that trees, shrubs, and grasses, accounting for 42.17% of the research area, are the predominant plant types in the greening construction area. The area of shrubs is the highest, reaching 17.29%; followed by trees, occupying 15.18%. Grasslands is the smallest, accounting for 9.7%；During the growth season, the total evapotranspiration water consumption in the green belt is 471.35×104m3, whereas trees, shrubs and grasslands is 182.27×104m3, 211.14×104m3,77.94×104m3, respectively. The groundwater recharge in the study area mainly originated from the mountain front lateral recharge, and the main discharge was the evapotranspiration water consumption of green belts. The latter accounts for 3.31 percent of the former. It is obvious that the construction of highway greenbelts has a substantial impact on the distribution of groundwater resources, and long-term evapotranspiration will cause groundwater levels to decline and the amount of accessible water resources to decrease.