ZENG Huaxian1,2, LI Yulin3, WANG Jingfu1, CHEN Jingan1,YANG Yongqiong1,4,WEI Xingyun1,4
(1.State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China;
2.University of Chinese Academy of Sciences, Beijing 100049, China;
3. Environmental Protection Monitoring Station of Two Lakes and One Reservoir in Guiyang, Guiyang 551400, China;
4. Guizhou Normal University, Guiyang 550025, China)
Abstract: In order to learn the dynamic changes of the water quality in Aha Reservoir, the water source of Guiyang City, the water quality monitoring data of the reservoir and its tributaries, and hydrological and meteorological data, was analyzed. The results showed that the nutrients, SD and Chl.a in reservoir regions and its tributaries presented seasonal variations, due to the cyclical effect of hydrometeorology and phytoplankton growth. The water quality of the reservoir region appeared to range from Class II to Class IV of surface water quality standard, and mainly in Class III. The water quality in the central area is superior to that in the east area, as the over standard rate of water quality was 19.82% in the central area and 45.05% in the east area. The trophic level index (TLI) analysis indicated that the reservoir water is in the mesotrophic state to mild eutrophic state. TLI indexes showed an overall trend of fluctuating decline over the years, suggesting that the water quality has been improved. The water quality of the tributaries is in decreasing order of Youyu River > Baiyan River = Caichong River>Jinzhong River. TP and NH3-N were proved as the main indexes exceeding the standard. Pearson correlation analysis showed that Chl.a presented a significant positive correlation to NH3-N, CODMn, temperature, precipitation, and sunshine duration in this reservoir; and a significant negative correlation was shown between Chl.a and SD, water level, and atmospheric pressure. Principal component analysis showed that algal growth was mainly controlled by hydrometeorological factors. At present, the crucial measurement to improve water quality in the reservoir shall be a more powerful rectification against external pollution such as Jinzhong River. In the future, the research on the processes and mechanisms of algal blooms affected by hydrological and meteorological factors should be strengthened to enhance the ability to deal with algal blooms.
Key word: Aha reservoir; water quality; trophic level index (TLI); nutrient; hydrometeorological factor
EARTH AND ENVIRONMENT Vol.49, No.4, Tot No.342, 2021, Page 367-374