River Health Assessment and Conservation Strategies for the Nanting River Basin

An evaluation system was established from four criterion layers—waterfront, water quantity & quality, aquatic biota, and social-service functions—together with 12 corresponding indicators to assess the health of the Nanting River basin. The results showed that Nanting River obtained an overall health score of 66.6, placing it in the “sub-healthy” category. Among the four layers, social-service functions rated “very healthy,” the waterfront was “healthy,” whereas water quantity & quality and biological status were “unhealthy.” Tributaries were generally healthier than the main stem. For the six county-level administrative reaches, health scores ranged from 63.1 to 68.9, all classified as sub-healthy. Among the five channel-type divisions, scores varied from 65.7 to 72.4, likewise all sub-healthy. At the indicator level, 45.0 % were very healthy, 12.2 % healthy, 20.6 % sub-healthy, 3.8 % unhealthy, and 18.3 % poor. Targeted protection measures were proposed to address the identified river-health issues.