| 摘要: |
| 为了确定内蒙古典型湖泊的水质演变特征，选取2013-2023年乌梁素海、岱海和南海湖的水质数据，采用综合污染指数和综合营养状态指数法分析各湖泊的水质演变特征与趋势，运用皮尔逊相关分析研究三个湖泊各水质指标与两个指数的相关程度，并且分析湖泊氮磷摩尔比（简称氮磷比）的时间序列变化趋势，探究影响湖泊水质变化的主要因素。结果表明：2013-2023年间，乌梁素海、岱海和南海湖的化学需氧量（CODCr）、总磷（TP）、氨氮（NH3-N）、叶绿素a（Chl.a）浓度总体呈下降趋势，乌梁素海和南海湖的TN浓度年际变化呈良好趋势发展，但岱海的总氮（TN）浓度在2020年达到最大值并保持劣Ⅴ类水标准；乌梁素海富营养化程度呈现从重度到中度再到轻度的变化趋势，岱海随着“引黄济岱”试水的完成，富营养化程度从重度转为中度，兼具游客观光功能的南海湖多年处于重度富营养化状态；综合污染指数法表明乌梁素海水质正向良性方向发展，岱海和南海湖在环境治理下重污染水质逐渐改善，但治理措施仍需进一步强化，其中岱海和南海湖受氮素污染明显，TN、TP、及CODCr 治理应成为三个湖泊污染治理的主要方面。回归线性模型分析，三个湖泊的Chl.a与TN、TP浓度均分别呈极显著正相关。通过氮磷比的比较，湖泊水体多数时间都适宜藻类生长繁殖，磷可能是乌梁素海Chl.a的主要影响因素，岱海和南海湖可能是氮、磷共同限制型湖泊。 |
| 关键词: 内蒙古湖泊 水质特征 富营养化 演变特征 |
| DOI： |
| 分类号: |
| 基金项目:国家自然科学基金项目（42167018）;内蒙古自治区自然科学基金项目（2024LHMS04016） |
|
| Variation characteristics and trend analysis of water quality of typical lakes in Inner Mongolia based on long time series |
|
Yang Wenhuan1, Li Yanfang1,2,3,2, Zhang Mingyu1,2,3,2, Gao Jingtian1,2,3,2, Li Weiping1,2,3,2
|
|
1.College of Energy and Environment,Inner Mongolia University of Science and Technology;2.PRChina;3.Collaborative Innovation Center of Autonomous Region for Ecological Protection and Comprehensive Utilization in the Inner Mon-golia Section of the Yellow River Basin
|
| Abstract: |
| To identify the water quality variation of typical lakes in Inner Mongolia, the water quality data of Lake Wuliangsuhai (WLSH), Daihai Lake (DH) and Nanhai Lake (NH) spanning from 2013 to 2023 were selected. The comprehensive pollution index and comprehensive trophic level index methods were employed to analyze the evolution characteristics and trends of water quality in each lake. Pearson correlation analysis was applied to investigate the correlation between various water quality indicators and the two indices in the three lakes. Additionally, the time series change trend of the nitrogen to phosphorus molar ratio (referred to as nitrogen-phosphorus ratio) was analyzed, so as to explore the main factors affecting the change of lake water quality. The results indicate that during 2013 to 2023, the concentrations of chemical oxygen demand (CODCr), total phosphorus (TP), ammonium nitrogen (NH3-N), and chlorophyll-a (Chl.a) in WLSH, DH, and NH exhibited a general downward trend. Additionally, the interannual variation of total nitrogen (TN) in WLSH and NH showed positive trends, but the concentration of TN in DH reached its maximum in 2020 and remained exceeded the standard value of Class V; The eutrophication level of WLSH shows a trend of changing from severe to moderate and then to mild. With the completion of the water test project of “diverting water from the Yellow River into Daihai”, the eutrophication level of DH has changed from severe to moderate. NH, which also serves as a tourist attraction, has been in a state of severe eutrophication for many years; The comprehensive pollution index method indicates that the water quality of WLSH is developing positively. Under environmental governance, the heavily polluted water quality of DH and NH is gradually improving, but the governance measures still need to be further strengthened. Among them, DH and NH are significantly polluted by nitrogen, and the governance of TN, TP, and CODCr should become the main aspects of pollution control for these three lakes. Regression linear model analysis showed that Chl.a in the three lakes were positively correlated with TN and TP concentrations respectively. By comparing the ratio of nitrogen to phosphorus, the lake water is suitable for algae growth and reproduction most of the time, phosphorus may be the main influencing factor of Chl.a in WLSH, while DH and NH may be lakes limited by both nitrogen and phosphorus. |
| Key words: The lakes of Inner Mongolian water quality characteristics eutrophication evolutionary features |
