Missing role of groundwater in water and nutrient cycles in the shallow eutrophic lake Kasumigaura, Japan

2008 ◽  
Vol 22 (8) ◽  
pp. 1150-1172 ◽  
Author(s):  
Tadanobu Nakayama ◽  
Masataka Watanabe
Keyword(s):  
Eutrophic Lake ◽  
Nutrient Cycles ◽  
Lake Kasumigaura ◽  
Shallow Eutrophic Lake

Characterization of natural organic matter in a shallow eutrophic lake

2002 ◽  
Vol 46 (11-12) ◽  
pp. 465-471 ◽  
Author(s):  
P.B. Thapa ◽  
F. Nakajima ◽  
H. Furumai
Keyword(s):  
Organic Matter ◽  
Natural Organic Matter ◽  
Similarity Index ◽  
Eutrophic Lake ◽  
Lake Kasumigaura ◽  
Characterization Methods ◽  
Spatial Changes ◽  
Different Seasons ◽  
Shallow Eutrophic Lake ◽  
The Difference

Natural organic matter (NOM) from five sampling stations of a shallow, eutrophic lake, Lake Kasumigaura was analyzed in four different seasons of a year by several NOM characterization methods including GPC and pyrolysis GC/MS with the objective of elucidating its characteristics as well as studying its temporal and spatial changes. A comparison was also made among the characteristics of NOM from this and two other lakes. The study showed that NOM in Lake Kasumigaura had comparable DOC, UVA260, and THMFP with that of Lake Inbanuma, but much higher than that of Lake Tsukui. Both molecular weight and polydispersities remained similar among those three sources but these values were significantly smaller in comparison with Suwannee River NOM. The similarity index analysis based on pyrochromatograms was useful to evaluate spatial and seasonal changes in NOM characteristics. Distinctive characteristics of NOM at KS1 (station near the mouth of Sakura River) were better explained by the difference in pyro-chromatograms rather than in general water quality. Except for KS1, the change in NOM characteristics in the lake water was found to be more pronounced in different seasons than at different locations.

scholarly journals Warming of water temperature in spring and nutrient release from sediment in a shallow eutrophic lake

2021 ◽  
Author(s):  
Ryuichiro Shinohara ◽  
Kenji Tsuchiya ◽  
Ayato Kohzu
Keyword(s):  
Water Temperature ◽  
Temperature Increase ◽  
Nonlinear Response ◽  
Nutrient Release ◽  
Eutrophic Lake ◽  
Lake Kasumigaura ◽  
Sediment Temperature ◽  
Shallow Eutrophic Lake ◽  
The Relationship ◽  
Temperature Water

Abstract We investigated whether recent springtime water temperature increases in a shallow eutrophic lake affected bottom sediment temperature and fluxes of ammonia (NH4+) and phosphate (PO43−) from the sediment. We conducted a lake-wide survey of Lake Kasumigaura, Japan, and analyzed the relationship between water temperature increases in spring and NH4+ and PO43− release fluxes. We also developed a numerical model to analyze how water temperature increase affects sediment temperature. Water temperature in May increased during 2010–2019 at a rate of 1.8–3.2 °C decade−1. The numerical simulation results showed that the water temperature increase was accompanied by a sediment temperature increase from a minimum of 18.3 °C in 2011 to a maximum of 21.6 °C in 2015. Despite the substantial difference in the observed sediment temperature (2.9 °C), no significant differences in NH4+ and PO43− fluxes in May between 2013/2014 and 2015 were found. These results suggest that both water and sediment temperatures are increasing in Lake Kasumigaura in spring, but it is unclear whether this warming has affected NH4+ and PO43− releases from the sediment. However, because a nonlinear response to sediment temperature was observed, future springtime warming may accelerate NH4+ and PO43− releases.

Role of organic phosphorus in sediment in a shallow eutrophic lake

2017 ◽  
Vol 53 (8) ◽  
pp. 7175-7189 ◽  
Author(s):  
Ryuichiro Shinohara ◽  
Mikiya Hiroki ◽  
Ayato Kohzu ◽  
Akio Imai ◽  
Tetsunori Inoue ◽  
...  
Keyword(s):  
Organic Phosphorus ◽  
Eutrophic Lake ◽  
Shallow Eutrophic Lake
Sign in / Sign up

Export Citation Format

Share Document