关键词: 土地利用/覆被变化;资源开发与利用;土地利用动态度;土地利用强度指数;长江经济带;

Abstract: Aiming at reducing the nitrogen and phosphorus pollution brought by rainwater, five native herbaceous plants of Chongqing City, including Zoysia matrella, Cynodon dactylon, Eremochloa ophiuroides, Bahiasgrass, and Axonopus compressus, were selected to investigate the removal efficiency of nitrogen and phosphorus in the initial runoff at rain gardens by leakage rate test and nitrogen and phosphorus removal test. The results showed that plants can ease the blockage in the medium layer. All of the five plants have good nitrogen removal efficiency in the rain gardens (removal rate up to 75%~95%), and the alternating wet and dry conditions have little effect on the denitrification process after the plants became mature. For the phosphorus removal, the discharge water from rain gardens still have high concentration phosphorus, however the form is particulate phosphorus that can hard be utilized by organism. Zoysia matrella and Cynodon dactylon have a good performance in nitrogen and phosphorus removal, and can adapt to the alternating wet and dry conditions. This result can provide technical support for the construction of rain gardens in sponge cities and the theory of nitrogen and phosphorus removal.

Key words: rain garden; nitrogen removal; phosphorus removal; water security; mountainous city