关键词: 水环境, 营养状态, 综合营养状态指数, 喀斯特湖泊, 百花湖

Abstract: The ecosystem of Baihua Lake is fragile and difficult to recover after destruction. Based on the comprehensive nutritional status index method, the water environment of Baihua Lake was evaluated by monitored physical and chemical parameters in wet season, normal season and dry season. The results showed that the properties of surface water of Baihua Lake were as follow: temperature of 11.2 ℃ - 22.5 ℃, pH value of 7.7 - 8.4, dissolved oxygenof 5.0 - 14.9 mg/L, transparency of 0.6 - 1.9 m, the total nitrogen and total phosphorus of 1.4 - 4.1, 0.030 - 0.964 mg/L respectively, and the ratio of nitrogen to phosphorus of 14.9 - 64.3, indicating that the lake was controlled by high nitrogen and phosphorus. Ammonia nitrogen was 0.01 - 1.85 mg/L. The nutritional status index of Baihua Lake was 29.56 in wet season, showing a poor nutrition state, while the index was 35.31 and 31.56 in normal and dry seasons respectively, showing a middle nutrition state. Baihua Lake is in poor-middle nutrition state overall, and the runoff input is the main nutrient source of Baihua Lake.

Key words: water environment, trophic state, comprehensive trophic state index, karst lake, Baihua lake