Abstract:

Suitable grasses for the slope protection of urban rivers in Shenzhen city were screened from 7 species in a simulated urban river. In the investigation , the indexes such as covering rate , biomass , slope adaptability , root characteristics , submergence tolerance and erosion resistance of the grasses were compared. The results show that all the 7 species can grow in the embankments along the simulated urban river , and that there are significant differences in the above-mentioned indexes of the cultivars after 4 months of cultivation. It is also demonstrated that P. notatum is a desirable species due to its highest covering rate (70%) , greatest biomass (8. 33 kg/ m² in drγ weight) and root biomass (2. 09kg/m²) and the most effective roots with a diameter of less than 1 mm. Furthermore , P. notαtum is of the best submergence tolerance and its half lethal time under partial and full drowned conditions is up to 45 d and 15 d , respectively. The block of P. notatum is also found to be resistant to an erosive velocity of 4. 0 m/ s. By considering all the above-mentioned statements , it is thus concluded that P. notαtum is the most suitable for the slope protection of urban rivers in Shenzhen city.

Key words: urban river, grass, submergence tolerance, slope protection, screening, Shenzhen city