本 實驗은 1980年 9月부터 1981年 8月까지 서울 地域을 흐르는 漢江의 四個 地域을 選定하여 總 細菌과 選擇培地에서 자란 병원성 細菌의 年中 分布를 조사하였다. 아울러 각 물리화학적 요인과 세균간의 상관 관계도 조사하였다. 調査 定點에서 水溫의 年中 變化는 0.3∼27℃의 범주로서 규칙적인 계절적 변화를 보였으며, pH의 경우 年平均 變化는 pH7.5∼pH7.7을 나타냈다. 溶存酸素의 年間 變化는 定點 1인 천호대교 부근이 비교적 높았으며 하류로 갈수록 점차 낮아졌으며 月間 變化는 1.6∼12.97㎎/ℓ였다. BOD의 年中 變化폭은 1.1∼16.0㎎/ℓ로써 上流쪽인 천호대교 부근과 下流쪽인 성산대교 부근간에 큰 差를 보였다. 암모니아態 窒素의 경우는 定點間 年平均값이 0.17∼2.53㎎-atN/ℓ였다. 亞窒酸態 窒素의 경우, 10.84∼39.04㎍-atN/ℓ로써 1977年∼1978年 洪等의 結果보다 전체적으로 높은 값을 보였다. 한편 窒酸態 窒素의 年中 分布는 3.21∼3.47㎎-atN/ℓ로서 調査 定點間 유사한 값을 보였다. 전기전도도의 年平均 값은 0.72∼0.88mΩ/㎝를 나타냈다. Nutrient Agar 培地에서 計數한 總 細菌의 分布는 年中 5.5×10 exp (3) - 3.6×10 exp (8) cells/㎎로서 定點 2가 최고값을 보였고 定點 1이 최저값을 나타냈다. MPN法으로 測定한 總大腸菌 및 糞便性 大腸菌의 菌體數는 각각 8.63×10 exp (3)∼2.41×10 exp (5) /100㎖, 1.39×10 exp (4) - 4.21×10 exp (5) /100㎖의 범주에서 변화하였다. Endo 및 EC에 의한 평판배지법으로 測定한 總大腸菌과 糞便性 大腸菌의 測定값도 MPN法에 의한 값과 유사하였다. 또한 선택배지에 나타난 Salmonella 및 Shigella群의 年中 分布는 9.68×10 exp (2) - 5.23×10 exp (3) cells/㎖의 범주였으며, Streptococci와 Staphylococci는 各各 3∼1.75×10 exp (2) cells/㎖, 1.51×10 exp (2) ∼ 2.79×10 exp (2) cells/㎖를 나타냈다. 各 物理化學的 要因과 微生物間적 상관관계에 의하면 定點 2, 定點 3, 定點 4에서 분변성 대장균과 분변성 室素源間에 밀접한 관계를 보였는데 이것은 이 地域水質을 잘 指標해 주는 것으로 判定된다.

Samples were taken from the surface waters of the main stream of Han river at four designated sites in Seoul city area from September, 1980 to August, 1981. Enumeration of total bacteria and pathogenic bacteria grown on selective media and correlation coefficient with six physico-chemical factors were studied. Temperature distribution showed a regular seasonal cycle and ranged from 0.3℃ to 27℃ during investigation. Every sites of water maintained stable pH values ranged from pH 7.5 to pH 7.7. The oxygen content of the water was, relatively high near Cheon Ho Bridge of site I and lowered along the downstream. The monthly values of oxygen concentration varied between 1.6㎎/ℓ and 12.97㎎/ℓ at all sites. It showed that the oxygen depletion was becoming severe along the downstream. Annual average value of BOD were found to be 2.97㎎/ℓ at site 1, 5.70㎎/ℓ at site 2, 7.85㎎/ℓ at site 3 and 8.84㎎/ℓ at site 4. Annual average concentration of ammonium-N varied between 0.17㎎-at N/l and 2.53㎎-at N/l. The nitrite-N concentrations were relatively high comparing with those which were measured in 1977-1978 by Hong et al., their annual values of concentration varied between 10.84㎍-at N/l and 39.04㎍-at N/l. The concentration of nitrate-N were demonstrated similar values of all sampling sites during investigation and they were in the range of 3.21-3.47㎎-at N/l.? The mean annual values of conductivity varied from 0.72mΩ/㎝ to 0. 88mΩ/㎝. The total bacteria counted by NA media were in the range of 5.5×10 exp (3) - 3.6×10 exp (8) cells/㎖. The population density of total bacteria was highest at site 2 and lowest at site 1. Annual average population density of total coliform and fecal coliform by MPN method were in the range of 8.63×10 exp (3) - 2.41×10 exp (5) /100㎖, 1.39×10 exp (4) - 4.21×10 exp (5) /100㎖, respectively. Enumeration of coliforms by Endo and EC media also showed similar population density comparing with MPN methods. The presence of fecal coliforms in surface water was more accurately correlated with fecal discharges than total coliform group. Mean annual population density of salmonella & shigella groups grown on selective media were in the range of 9.68×10 exp (2) - 5.23×10 exp (3) cells/㎖ and that of streptococci and staphylococci were 3-1.75×10 exp (2) cells/㎖, 1.51×10 exp (2) - 2.79×10 exp (2) cells/㎖, respectively. According to correlation coefficients, fecal coliforms at site 2, site 3 and site 4 might closely relate with domestic waste origin of nitrogen sources.