The results of WQI in different layers.

This study aimed to analyze the spatial and temporal variations in water quality status and eutrophication level of Lake Aha, influenced by human activities and seasonal changes. Ten indicators were sampled and analyzed at seven sampling points in Lake Aha in different seasons and vertical layers. The eutrophication level and water quality status were evaluated using the Trophic Level Index (TLI) and Water Quality Index (WQI). Results showed that the average TLI and WQI values during the wet season (July) were 31.06 and 92.14, respectively, compared to 28.64 and 109.14 during the dry season (April). Eutrophication was more severe in the wet season than in the dry season, whereas water quality was poorer in the dry season than in the wet season. The main factors driving these patters were temperature and precipitation, respectively. Spatially, the northern part of Lake Aha exhibited higher eutrophication levels than the southern part, while water quality was better in the south than in the north, largely due to the impact of human activities. Significant differences in eutrophication levels and water quality were observed among the seven sampling points, though variations across vertical layers were minimal. Strong positive correlations between key indicators—such as CODMn, TP, and Chl-a—highlighted interdependencies affecting overall water quality, with these factors identified as critical drivers of TLI and WQI. These findings indicate the important impacts of seasonal changes and human activities on the water quality of Lake Aha and suggest the need for targeted water pollution management strategies.

本研究旨在分析受人类活动与季节变化共同影响的阿哈湖水质状况及富营养化水平的时空分异特征。本研究在阿哈湖的7个采样点，针对不同季节与垂直水层采集并分析了10项指标，采用营养状态指数（Trophic Level Index, TLI）与水质指数（Water Quality Index, WQI）对富营养化水平及水质状况进行评价。结果显示，丰水期（7月）的TLI与WQI平均值分别为31.06与92.14，枯水期（4月）的对应数值则分别为28.64与109.14。丰水期富营养化程度较枯水期更为严重，而枯水期水质状况较丰水期更差，驱动上述格局的主要因素分别为温度与降水。空间维度上，阿哈湖北部的富营养化水平高于南部，而南部水质优于北部，这在很大程度上源于人类活动的影响。7个采样点间的富营养化水平与水质状况存在显著差异，但不同垂直水层间的差异极小。关键指标（如高锰酸盐指数CODMn、总磷TP与叶绿素a Chl-a）之间存在显著正相关关系，揭示了影响整体水质的相互依存关联，上述因子被确定为影响TLI与WQI的关键驱动因素。本研究结果表明，季节变化与人类活动对阿哈湖水质具有重要影响，并提示需制定针对性的水污染治理策略。