| 1 | They are controlled by catchment basins which are combined with high, medium and low anomaly; | |
| 2 | The catchment area played a dominant role in determining surface runoff. | |
| 3 | Mekong river nature reserve is the catchment area of international famous mekong river. | |
| 4 | At night the flower closes and sinks underwater, at dawn it rises and opens again. | |
| 5 | Finally, on the basis of surface flow area calculation model, it realizes design and calculation for rainwater pipe catchment division. |