Research On Environmental Problems Of Water Landscape Planning In Chongqing Olympic Garden

In recent years, the construction of water landscape in city is more and more emphasized, but some of the designs of water landscape still have some problems, such as only considering the landscape effect, neglecting the construction of water system, which results in the water landscape lake of self-attendance and circulatory ability, the instability of water ecosystem and the quality and quantity of the water can't be assured. As time goes on, the landscape effects also decreased. So, to ensure the continuity of the water landscape, the design should be based on small watershed eyesight.This study was focused on the environmental applications such as small watershed geography, soil, quality and quantity of water in the planning of the water landscape in Chongqing Olympic Garden water system by systematology and ecology. To ecology design, this paper analyzed the small watershed geography, the water volume balance, the nutrients input output condition and the soil flows input of the wetland landscape and the reservoir in Olympic Garden. The main results were as follows:(1) The water system of the Chongqing Olympic Garden is composed of three water landscapes, pool, wetland landscape and reservoir. Wetland landscape and reservoir are mostly important water landscape resources. The area of the wetland is 2.2 hm~2, and the reservoir is 8.5 hm~2. The watershed concludes four types of soil, purple soil, dark purple soil, yellow earth and purple bone stone soil. The purple soil is the main type, is mostly distributed in the lower body of the mountain and takes about 59% of the small watershed. The vegetation forms of the watershed are mostly secondary or artificial vegetation form. The ratio of wood: shrub is 1:3, the ratio of evergreen species: deciduous tree is 1:4.(2) The input and output water quantity of the wetland is 24.3×10~4m~3 and 10×10~4 m~3, respectively. The input water quantity can satisfy the water demands of the wetland landscape. Access to release floodwater was designed for the output of superfluous water and improves renew of the water landscape. The cycle time of the water landscape in wetland is 268d, achieved the index of 1:1 water body change. The input and output water quantity of the reservoir of Chongqing Olympic Garden is 78.1×l0~4m~3and 32.62×10~4 m~3, respectively. The annual water quantity for the reservoir change is 45.48×10 m3. The cycle time of the reservoir is 268d, higher than the index of 1:1 water change. The input water quantity only can satisfy very little exchange, the reservoir has eutrophication or the increase eutrophication degree possibility.(3) The balance situation of the nutrition material of water landscape was analyzed by monitoring the input and output of the water quality of the water landscape in Chongqing Olympic Garden. The input water quality of the wetland landscape and the reservoir are midrange contaminated while the input water quality of the reservoir is eutrophication. So, design of the water landscape should be based on internal and external controls to make sure the water quality.(4) The soil erosion of the mountains in the small watershed of the Chongqing Olympic Garden results in input of 148.16t silt to the wetland landscape and 331.09t to the reservoir, most of these silts were deposited in the water landscape. The long-time silt deposition can decrease or vanish the water landscape. The erosion and torrent control works such us revegetation combined with warp land dam and blocking slag wall et al. can control the course of soil erosion and transportation stage, decrease the input of the settlings.