Eco-hydrological Effects Of Rainfall Interception For Three Turfgrasses

With its function of environmental and regulating urban ecological climate, trufgrass is playing an important role in ecological system. But with the increasing seriousness of water resource shortage and the upswing of the growing area of lawn, improve the efficiency of lawn irrigation water is particularly important and urgent. Water was intercepted by canopy leaves when rainfall and irrigation happens. As rainfall increased or prolonged, the surplus water dripped into soil and utilized by root, which is considered as effective rainfall. Most part of these water was evaporated into atmosphere, a very small part was absorbed by leaves.Carried out by Zoysia, Kentucky bluegrass and Tall fescue, the absorption on surface of three turfgrasses leaf was measured through an experiment performed by living organism, and the process of dynamic change and affect factors of interception and evaporation was studied by weighing the difference. The result showed that:The relationships between water absorption rate and time accorded with power function, it was high at the beginning, and then gradually leveled off. Total amount of water absorption at per leaf area and per dry weight were different. In the amount of saturated leaf weight, per unit of leaf area of Tall fescue was the highest, while per unit dry matter of Kentucky bluegrass is the highest.The amount of intercepted water were higher than their fresh weight, in accordance of descending order is Zoysia, Tall fescue and Kentucky bluegrass. Interception was positively correlated with leaf area. Under ideal conditions, the interception rate of Zoysia, Kentucky bluegrass and Tall fescue is85.51%,79.25%and70.45%.In same rainfall intensity, the relationships between interception and precipitation accorded with power function, it was high at the beginning, and then gradually leveled off. The higher of mowing height, the more of the amount of the final interception, Interception of Kentucky bluegrass was always the smallest, while relationship between Tall fescue and Zoysia depends upon different circumstance. Under different rainfall intensity, interception was negatively correlated with precipitation. Interception rate also increases with the mowing height.The relationships between evaporation and time accorded with logarithmic function, it was high at the beginning, and then gradually leveled off. In accordance of descending order, evaporation accounts for interception ratio is Tall fescue, Zoysia and Kentucky bluegrass, which most of the interception were evaporated.