LAGUNA10 47 56 2003 3 LAGUNA 10 p.47 56 2003 1997 2001 1 2 2 Water quality of Lake Kamo, Sado Island, northeast Japan, 1997 2001 Katsuaki Kanzo 1, Niigata Prefectural Ryotsu High School Science Club, Iwao Kobayashi 2 and Masaaki Tateishi 2 Abstract: We have examined the water quality of the Lake Kamo over a 4-year period from August 1997 to August 2001 at 17 observation sites that were set up at 250-m intervals along a N-S line in the lake. Measurements on water temperature, salinity, density, transparency, dissolved oxygen and ph were made at all the observation sites for every depth interval of 50 cm. Thus the data were obtained from a total of 180 measurement points during the entire study period, except on certain stormy days. The data were analyzed and the results are summarized. Key words: Kamo Lake, lagoon, monitoring, natural environment, water quality 1997 8 2001 8 4 250 m 17 50 cm 1 180 4 11 12 3 1 Fig.1. Map showing the location of the Lake Kamo. 1 2 Niigata Prefectural Sado High School Faculty of Science, Niigata University 47
48 167 160 250 2 3 1960 1970 30 2 Fig. 2. Bathymetry of Lake Kamo. 1 30 5 km 2 46 10 km 2km 2 9m 5m 260 m 3 4m 30 m 0.9 m sec 6 1997 6 1 10 4.2 km 4.2 km 3.8 km 4 2 5430 ha 11 1 3 2,202 10,859 5 3 1997 4m 6 9 m 3 250 m 2E 3 D 4 D 5 D 6 D 7 E 8 E 9 E 10 F 11 G 12 H 13 H 14 H 15 H 16 H 17 H 18 H 17 2 E 4 D 6 D 7 E 9 E 11 G 12 H 14 H 16 H 18 H 10 6 D 11 G 16 H 3 COD 2E 10 F 11 G 13 H 14 H 18 H 18 H 2E mpsu tph YSI-model 85,pH PH TPX-90 i
1997 2001 49 1 Table 1. Observation dates. days on which observations were stopped due to stormy weather; **, days on which water sampling could not be made due to stormy weather. 3 17 1 8 13 5 10 4 3 COD NO 2 PO 4 MBAS Fig. 3. Location of observation sites. 17 sites where observations were made for 8 hours aday. 13 sites at which measurements were made for 5 hours in the morning. 10 sites at which measurements were made for 4 hours in the afternoon. 3 sites where COD, NO2, PO4 and MBAS were measured. 4 1 1 2 3 4 250 m 50 cm 1 4 4 4a 5 11 G 4 4 1991 8 1 35.3 1999 2 34.7 5a 13.7 5a 3 9 4 1999 7 31.910 F 1997 12 6.0 17 H 4a 19.6 17
50 a d b e c f 4 2 E18 H 10 km abpsu c t d m e fph Fig. 4. Trends in water quality parameters. a, temperature ; b, salinity PSU ; c, densityt ; d, transparency m ; e, dissolved oxygen ; f, ph., average value of the surface measurements;, average value of the bottom measurements;, average of the measured values at all the points between the surface and bottom;, difference in average of surface and bottom values.
1997 2001 51 3 4a 2 4a 3 9 10 2 5a 5a 1 2 3 1 4 9 3 10 12 3 0.7 26 psu 32 psu 30 psu 4b 18 H 2E 1psu 4b 1 psu 7 81 5b 30 cm 5b 1998 8 04 200 mm 17.8 t 22.5 t 20.8 t 4c 18 H 2E 1 t 4c 3 4 2 t 1 5c 5c 10 11 8 5c 1998 8 04 200 mm 2 2.5 1 4 5 m 9m 4.5 m 50 4 d 4d 4 5 m 2000 11 88 42 69 4e 3 4e 73
52 a b d c e 5 11 G a bpsu c t d 30 eph Fig. 5. Temporal changes in the water quality at the observation site 11 G in the central part of the Lake month-year of observation on the horizontal axis; water quality parameter on the vertical axis. a, air and water temperatures, average of the daily maximum and minimum temperatures;, period when the surface water temperature was higher than that of the bottom;, period when the surface water temperature was lower than that of the bottom ; b, salinity PSU ; c, densityt ; d, dissolved oxygen, period when the DO is lower than 30; e, ph., measured value of surface water;, measured value of bottom water;, difference between surface and the bottom.
1997 2001 53 4e 61 3 30 62 30 5d1998 8 4 8 10 0 10 120 ph ph 8.1 7.8 8.0 4f ph 4f ph ph 4e f1999 6 1999 11 ph 4 4 180 11 G 4 6 6a 6c 6b 6d 6e 6f 6g ph 6a 1998 2 1998 3 2001 3 1 4 9 1997 8 6 10 12 1997 12 7 10 11 1997 11 1998 8 1998 10 3 1998 8 4 6 9 6 25 30 psu 2001 2000 8 17 mm 2001 7 2001 8 81 mm 6d 10 psu
神蔵勝明 新潟県立両津高校理科部 小林巖雄 立石雅昭 54 a b c d e f g 図 6 湖中央 観測点 11 G での時系列等値線図 横軸は観測月 縦軸は深度 m a 日最高気温 b 水温 c 月別降雨量 mm d 塩分 PSU e 密度 σt f 溶存酸素量 と透 明度 m g ph. Fig. 6. Time series isometric lines of water quality parameters at observation site 11 G in the central part of the Lake date month of observation on the horizontal axis and water quality parameter on the vertical axis. a, maximum air temperature ; b, water temperature ; c, monthly precipitation mm ; d, salinity PSU ; e, density σt ; f, dissolved oxygen and transparency, m ; g, ph.
1997 2001 55 1998 8 1998 8 4 24 200 mm 1.5 m 6d 1.5 m 10 11 1 6e 1998 8 1998 10 2 1998 11 6f 3 1997 8 2000 8 1998 3 1998 6 1999 4 1999 8 2000 5 1998 8 4 24 200 mm 1.5 m 0.3 0.9 m 1998 7 25 50 70 1998 8 5 6m 10 24 1998 9 1998 10 1998 11 30 10 1998 10 1.5 m 30 0 1.5 m 100 120 1998 8 30 2 COD 30 1 100 100 100 1997 8 1998 2 1998 10 1998 12 2001 5 2001 8 6f 6e 1997 8 1998 8 1998 9 1998 10 1999 8 1999 10 2000 7 2001 7 2001 8 1998 2 3m 100 120
56 ph ph ph ph 6 gph ph 1997 12 1998 2 1998 9 1998 10 4 180 pdf http: //www.kisuiiki.shimane-u.ac.jp 55 4 179 1 2 199802.pdf 3 199803.pdf 200103.pdf 4 199804.pdf 199904.pdf ** 200104.pdf 5 199805.pdf 199905.pdf 200005.pdf 200105.pdf 6 199806.pdf 199906.pdf 200006.pdf 200106.pdf 7 199807.pdf 199907.pdf 200007.pdf 200107.pdf 8 199708.pdf 199808.pdf 199908.pdf 200008.pdf 200108.pdf 9 199709.pdf 199809.pdf 200009.pdf 10 199810.pdf 199910.pdf 200010.pdf 11 199711.pdf 199811.pdf 199911.pdf* 200011.pdf 12 199712.pdf 199812.pdf* 200012.pdf 1998 LAGUNA No.5, 137-152. 1998 1996 8 7 9 A-1 83-136. Nguyen Lap Van 1997 8 9 C 5-34.