丹江口库区及其上游流域水质安全保障成效评估及"十五五"对策建议OA

To systematically evaluate the effectiveness of water quality security in the Danjiangkou Reservoir area and its up-stream watershed,the water source area of the Middle Route of South-to-North Water Diversion Project,and to scientifically formulate governance strategies for the 15th Five-Year Plan period,an effectiveness evaluation and situation assessment were conducted through field surveys and systematic analysis,focusing on key indicators such as the water quality compliance rate,the proportion of sections with water quality better than Class Ⅲ,total nitrogen concentration,sewage treatment rate,newly added soil erosion control area,aquatic biological integrity index,reservoir trophic state,and regional green and high-quality development index.The results show that by 2025,the water quality compliance rate at national monitoring sections in the water source area re-mained at 100%,and the proportion of sections with water quality better than Class Ⅲ reached 100%.The urban sewage treat-ment rate significantly increased,the newly added soil erosion control area exceeded the planned target,the reservoir was generally in a mesotrophic state,the total nitrogen concentration decreased significantly compared to the binding target,the aquatic biologi-cal integrity index steadily improved,and the regional green and high-quality development pattern began to take shape.However,challenges remain prominent,including excessive total phosphorus and abnormal algal proliferation in some tributaries and reser-voir bays,insufficient intelligence level and coverage of monitoring systems,weak resilience of water supply security,and imperfect long-term financial guarantee mechanisms.Looking ahead to the 15th Five-Year Plan period,the study proposes key counter-measures,including refined control of water quality risks,the construction of an integrated"space-air-ground-water-engi-neering"intelligent monitoring system,optimization of water resource regulation,the establishment of a diversified funding guaran-tee mechanism,and strengthening research on key technologies,thereby providing scientific and technological support to ensure a perpetual flow of clear water to the north.