ABSTRACT
To understand the impact of an artificial intervention on rivers during rapid urban development, such as the ecological destruction of water systems and the blockage of aquatic pathways, we conducted field research on two typical rivers (the Kunyu River and the Shuiya Ditch)in Beijing. The study found that the Kunyu River is mainly a hard boundary, with physical barriers to biological exchange such as sluice gates, and that the river has a single species of aquatic plants and is rich in aquatic organisms, mainly hatchlings of loach, shrimps, minnows, crucian carp, and warbler, with few adults. Shuiya Ditch is dominated by ecological barges, and there are physical barriers such as waterfalls and barrages in the river, with fewer aquatic animals. It is thought that the water-blocking structures in urban rivers have blocked aquatic pathways and that the movement of individuals is mainly unidirectional downstream, with a lack of two-way communication, causing ecological fragmentation in many water systems and making it difficult to maintain the long-term survival of adult fish in local waters. Water system connectivity is essential for the long-term stability of river ecosystems. This paper combines the calculations of mathematical models to propose specific and feasible suggestions and measures for the restoration of aquatic pathways such as the construction of fish passages, with a view to providing a reference for the construction of urban river water ecology.
