Abstract:
Artificial greenspace is one of the important measures to build sponge city, which has the function of water storage and flood control. Its main influencing factors are soil infiltration and water conservation capacity, which different among vegetation types of greenspace. In order to explore the different influences of vegetation types on soil infiltration and water conservation capacity, three types (arbor, shrub and grass greenspace) of greenspace in Huaxi district of Guiyang city were selected. The saturated hydraulic conductivity and volumetric water content of shallow greenspace soil (0 - 10 cm, 10 - 20 cm, 20 - 30 cm) during rainy and dry seasons were analyzed in this study. The results showed that the soil saturated hydraulic conductivity was the largest in arbor greenspace but the smallest in grass greenspace, and small difference was found between shrub and grass greenspace. The saturated hydraulic conductivity was mainly affected by soil bulk density, total porosity, capillary porosity, non-capillary porosity and rock fragment content. In rainy season, the volumetric soil water content in arbor greenspace was the highest, followed by grass greenspace, and shrub greenspace was the lowest. Although arbor consumed more water, its canopy shading limited the evaporation of soil water. In dry season, the volumetric soil water content in shrub greenspace was the highest, followed by grass greenspace, and arbor greenspace was the lowest. During dry season, the temperature is relatively low, the evaporation rates of soil moisture of all types of greenspace are similar to each other. Due to the root characteristics of herbaceous plants, the grass greenspace consumed much less water in dry season. In conclusion, shrub greenspace has strong soil water conservation capacity which exhibited small evaporation during drought, and arbor greenspace has strong water holding capacity which stored most water after rainfall. We suggest to design more arbor and shrub greenspace and to set up protection measures in the early stage of artificial vegetation construction to reduce human interference.