start-ver=1.4 cd-journal=joma no-vol=14 cd-vols= no-issue=4 article-no= start-page=143 end-page=149 dt-received= dt-revised= dt-accepted= dt-pub-year=2020 dt-pub=2020 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Estimation of long-term external nutrient loading from watersheds to Lake Biwa by a combined rainfall-runoff model and loading-discharge curve approach en-subtitle= kn-subtitle= en-abstract= kn-abstract=External nutrient loadings to Lake Biwa were estimated using a combined tank model and loading-discharge curve approach. The model was applied to collective drainage basins of the lake’s Imazu (northwest), Hikone (northeast), and Otsu (south) areas. The hourly model was conducted using particular discharges from Kita (Ado) river, Takatoki (Ane) river, and Yasu River to obtain loading curves for phosphate (PO4) and silica (SiO2) by assimilating measured concentrations (2002–2003). The tank model was updated by adding an evapotranspiration routine and direct paths of groundwater discharges to the lake floor. The daily model was calibrated through analysis of water budget among the basin, inflow, lake and outflow, and then validated. The model was established and combined into a loading-discharge curve to determine the long-term external nutrient loadings entering the lake (1980–2017). Seasonal variation in nutrient loadings increased during spring and summer and decreased during winter. Annual phosphate-phosphorus (PO4-P) loading ranged from 217 to 296 tons yr–1 in the North Basin and 45 to 76 tons yr–1 in the South Basin, while SiO2 loading fluctuated from 16,027 to 32,655 tons yr–1 and 2,518 to 5,490 tons yr–1 in the North and South Basins, respectively. en-copyright= kn-copyright= en-aut-name=Le TienHuu en-aut-sei=Le Tien en-aut-mei=Huu kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=OkuboKenji en-aut-sei=Okubo en-aut-mei=Kenji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=Ho ThiPhuong en-aut-sei=Ho Thi en-aut-mei=Phuong kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=SaitoMitsuyo en-aut-sei=Saito en-aut-mei=Mitsuyo kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= affil-num=1 en-affil=Graduate School of Environmental and Life Science, Okayama University kn-affil= affil-num=2 en-affil=Graduate School of Environmental and Life Science, Okayama University kn-affil= affil-num=3 en-affil=School of Chemical, Biological and Environmental Technologies, Vinh University kn-affil= affil-num=4 en-affil=Graduate School of Environmental and Life Science, Okayama University kn-affil= END start-ver=1.4 cd-journal=joma no-vol= cd-vols= no-issue= article-no= start-page=93 end-page=100 dt-received= dt-revised= dt-accepted= dt-pub-year=2014 dt-pub=201406 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Seto Inland Sea tidal flow simulation en-subtitle= kn-subtitle= en-abstract= kn-abstract= en-copyright= kn-copyright= en-aut-name=MORIFUJIShinya en-aut-sei=MORIFUJI en-aut-mei=Shinya kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=SUITOHiroshi en-aut-sei=SUITO en-aut-mei=Hiroshi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=ROPPONENJanne en-aut-sei=ROPPONEN en-aut-mei=Janne kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=OKUBOKenji en-aut-sei=OKUBO en-aut-mei=Kenji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= affil-num=1 en-affil= kn-affil= affil-num=2 en-affil= kn-affil= affil-num=3 en-affil= kn-affil= affil-num=4 en-affil= kn-affil= END start-ver=1.4 cd-journal=joma no-vol= cd-vols= no-issue= article-no= start-page=76 end-page=92 dt-received= dt-revised= dt-accepted= dt-pub-year=2014 dt-pub=201406 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Simplified approach to evaluate total external loading to Kojima Lake en-subtitle= kn-subtitle= en-abstract= kn-abstract= en-copyright= kn-copyright= en-aut-name=NISHIMURAShin-ichi en-aut-sei=NISHIMURA en-aut-mei=Shin-ichi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=OKUBOKenji en-aut-sei=OKUBO en-aut-mei=Kenji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=MORITAHidenori en-aut-sei=MORITA en-aut-mei=Hidenori kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=KOSKIAHOJari en-aut-sei=KOSKIAHO en-aut-mei=Jari kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=TATTARISirrka en-aut-sei=TATTARI en-aut-mei=Sirrka kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= affil-num=1 en-affil= kn-affil= affil-num=2 en-affil= kn-affil= affil-num=3 en-affil= kn-affil= affil-num=4 en-affil= kn-affil= affil-num=5 en-affil= kn-affil= END start-ver=1.4 cd-journal=joma no-vol= cd-vols= no-issue= article-no= start-page=69 end-page=75 dt-received= dt-revised= dt-accepted= dt-pub-year=2014 dt-pub=201406 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Total loading curves applied to Lake Pyhäjärvi en-subtitle= kn-subtitle= en-abstract= kn-abstract= en-copyright= kn-copyright= en-aut-name=OKUBOKenji en-aut-sei=OKUBO en-aut-mei=Kenji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=KOSKIAHOJari en-aut-sei=KOSKIAHO en-aut-mei=Jari kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=VENTELÄAnne-Mari en-aut-sei=VENTELÄ en-aut-mei=Anne-Mari kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=HUTTULATimo en-aut-sei=HUTTULA en-aut-mei=Timo kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= affil-num=1 en-affil= kn-affil= affil-num=2 en-affil= kn-affil= affil-num=3 en-affil= kn-affil= affil-num=4 en-affil= kn-affil= END start-ver=1.4 cd-journal=joma no-vol= cd-vols= no-issue= article-no= start-page=57 end-page=57 dt-received= dt-revised= dt-accepted= dt-pub-year=2014 dt-pub=201406 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=(Abstract for Journal paper) Waves in two shallow lakes in different latitudes with climate change perspective – measurements and forecasts en-subtitle= kn-subtitle= en-abstract= kn-abstract= en-copyright= kn-copyright= en-aut-name=WUTing Feng en-aut-sei=WU en-aut-mei=Ting Feng kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=OKUBOKenji en-aut-sei=OKUBO en-aut-mei=Kenji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=HUTTULATimo en-aut-sei=HUTTULA en-aut-mei=Timo kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=ROPPONENJanne en-aut-sei=ROPPONEN en-aut-mei=Janne kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= affil-num=1 en-affil= kn-affil= affil-num=2 en-affil= kn-affil= affil-num=3 en-affil= kn-affil= affil-num=4 en-affil= kn-affil= END start-ver=1.4 cd-journal=joma no-vol= cd-vols= no-issue= article-no= start-page=48 end-page=56 dt-received= dt-revised= dt-accepted= dt-pub-year=2014 dt-pub=201406 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=The sink of sediments suspended by waves in Lake Pyhäjärvi en-subtitle= kn-subtitle= en-abstract= kn-abstract= en-copyright= kn-copyright= en-aut-name=OKUBOKenji en-aut-sei=OKUBO en-aut-mei=Kenji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=HUTTULATimo en-aut-sei=HUTTULA en-aut-mei=Timo kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=SUITOHiroshi en-aut-sei=SUITO en-aut-mei=Hiroshi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=ROPPONENJanne en-aut-sei=ROPPONEN en-aut-mei=Janne kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=MANOAkiko en-aut-sei=MANO en-aut-mei=Akiko kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=NAKAZAWATakashi en-aut-sei=NAKAZAWA en-aut-mei=Takashi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= affil-num=1 en-affil= kn-affil= affil-num=2 en-affil= kn-affil= affil-num=3 en-affil= kn-affil= affil-num=4 en-affil= kn-affil= affil-num=5 en-affil= kn-affil= affil-num=6 en-affil= kn-affil= END start-ver=1.4 cd-journal=joma no-vol=1 cd-vols= no-issue=1 article-no= start-page=77 end-page=89 dt-received= dt-revised= dt-accepted= dt-pub-year=1996 dt-pub=199603 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Turbid intrusion below the thermal staircase in the seasonal thermocline of Lake Biwa en-subtitle= kn-subtitle= en-abstract= kn-abstract=Thermal 'staircase', a layer of constant temperature between the sheets of the steep gradients, was formed in the seasonal thermocline, which was 2.5 m above the bottom at a point of 18 m deep on the boundary slope in Lake Biwa. Following a sediment resuspension event when a moderate onshore wind blew, bed materials should be suspended up to the thermocline, then settled down forming a staircase above the turbid intrusion. Comparing the observed downward hear flux with the settling flux of sediment, it was found that double-diffusive convection would play an important role on the formation of the whole structure consisting of the staircase and turbid intrusion along with chemical anomalies and dense population of phytoplankters, which were fed by nutrients supplied from the bottom sediment under a typical condition of drought. Laboratory experiments were conducted to demonstrate the thermal and sediment processes in the stratified lake. Resuspension process due to surface and internal waves was examined using a tank with a sloping bottom, while the settling process was investigated by using a deep, diffusive tank. Formative process and scales of the staircase and intrusion were discussed relating with the intensity of resuspension and the buoyancy fluxes. en-copyright= kn-copyright= en-aut-name=OkuboKenji en-aut-sei=Okubo en-aut-mei=Kenji kn-aut-name=大久保賢治 kn-aut-sei=大久保 kn-aut-mei=賢治 aut-affil-num=1 ORCID= en-aut-name=MorikawaHiroshi en-aut-sei=Morikawa en-aut-mei=Hiroshi kn-aut-name=森川浩 kn-aut-sei=森川 kn-aut-mei=浩 aut-affil-num=2 ORCID= en-aut-name=KimotoTakashi en-aut-sei=Kimoto en-aut-mei=Takashi kn-aut-name=紀本岳志 kn-aut-sei=紀本 kn-aut-mei=岳志 aut-affil-num=3 ORCID= en-aut-name=TanakaYuji en-aut-sei=Tanaka en-aut-mei=Yuji kn-aut-name=田中祐志 kn-aut-sei=田中 kn-aut-mei=祐志 aut-affil-num=4 ORCID= affil-num=1 en-affil= kn-affil=岡山大学 affil-num=2 en-affil= kn-affil=Department of Civil Engineering, Faculty of Engineering, Kyoto University affil-num=3 en-affil= kn-affil=Research Institute of OceanoChemistry, c/o Faculty of Science, Kyoto University affil-num=4 en-affil= kn-affil=Department of Fisheries, Faculty of Agriculture, Kinki University END start-ver=1.4 cd-journal=joma no-vol=3 cd-vols= no-issue=1 article-no= start-page=97 end-page=104 dt-received= dt-revised= dt-accepted= dt-pub-year=1998 dt-pub=19980114 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Surface Air Temperature Distribution : A Study from Southwest Bangladesh en-subtitle= kn-subtitle= en-abstract= kn-abstract=Surface air temperature distribution over the Ganges Delta Region of southwest Bangladesh and its tendency of warming are discussed through the analyses based upon the long-term temperature data from 1900-93. The data consist of two parts corresponding to the time-periods: 1973-93 and 1900-72. The study area is one of most affected places by the annual monsoon hydrological cycle and the present observation from these temperature data indicate that the surface air temperature gradient in the north-south direction is significant in the rainy season and that the temperature of the region is at an increasing tendency; the warming rate during the data periods (1900-93) on the long-term mean annual basis is estimated as 0.77℃ at Satkhira of the Khulna division and 0.29℃ as an areal average including the Barisal division, for the time difference of about half a century between the data periods before and after 1972. en-copyright= kn-copyright= en-aut-name= en-aut-sei= en-aut-mei= kn-aut-name=HassanMuhammad Qumrul kn-aut-sei=Hassan kn-aut-mei=Muhammad Qumrul aut-affil-num=1 ORCID= en-aut-name=OkuboKenji en-aut-sei=Okubo en-aut-mei=Kenji kn-aut-name=大久保賢治 kn-aut-sei=大久保 kn-aut-mei=賢治 aut-affil-num=2 ORCID= affil-num=1 en-affil= kn-affil=Department of Geology, University of Dhaka affil-num=2 en-affil= kn-affil=岡山大学 END