대청호의 부의양화에 관한 조사 연구

Abstract

A study on tropic states of Daechung Reservoir was conducted at 5 sampling stations from February through October 1995. The results are summarized as follows ; 1. The range of pH of the water of the reservoir was 7.4~8.1(The average was 7.7) 2. The range of DO was 4.1~11 mg/ℓ (The average was 8.0 mg/ℓ) and the range of COD was 1.8~4.1 mg/ℓ (The average was 3.2 mg/ℓ). The quality of the water in the reservoir was within the class 3 water criteria set by the ministry of environmental protectlon. 3. The concentrations of total nitrogen and total phosphorus were 1.22 mg /ℓ and 0.040 mg/ℓ respectively. The concentration of nitrogen, was thirty time higher than that of phosphorus and phosphorus acted as a limiting factor for eutrophic state of the water. Eutrophic states were noted at all sampling points in February, April, June, August, and October. 4. The range of chlorophyll-a was 2.0~10.2 mg/m3(The average was 5.2 mg/m3 ) , and the water was mesotrophic state in Chlorophyll- a. 5. The range of transparency was 1.4~3.6 m(The average was 2.1 m) and the water was mesotrophic sta te in transparency. 6. The trophic state of the water by the TSI wasas follows;The range of phosphorus was 51~61(The average was 57 TSI), and the state of water was eutrophic. The range of chlorophyll-a was 38~54(The average was 45 TSI) and the state of water was mesotrophic. The average of transparency was 44~55(The average was 50 TSI) and water state was mesotrophic. By the results of the study, it was assumed that active photosynthesis was being pro gressed and the state of water was meso-eutrophic. It is recommended that proper measure be taken to prevent eutrophic state of the reservoir.