scholarly journals Interannual and long-term changes in the trophic state of a multibasin lake: effects of morphology, climate, winter aeration, and beaver activity

2016 ◽  
Vol 73 (3) ◽  
pp. 445-460 ◽  
Author(s):  
Dale M. Robertson ◽  
William J. Rose ◽  
Paul C. Reneau
Keyword(s):  
Water Quality ◽  
Trophic State ◽  
Secchi Depth ◽  
Climatic Changes ◽  
Main Flow ◽  
Temperature And Precipitation ◽  
Air Temperatures ◽  
Long Term Changes ◽  
P Sources

Little St. Germain Lake (LSG), a relatively pristine multibasin lake in Wisconsin, USA, was examined to determine how morphologic (internal), climatic (external), anthropogenic (winter aeration), and natural (beaver activity) factors affect the trophic state (phosphorus, P; chlorophyll, CHL; and Secchi depth, SD) of each of its basins. Basins intercepting the main flow and external P sources had highest P and CHL and shallowest SD. Internal loading in shallow, polymictic basins caused P and CHL to increase and SD to decrease as summer progressed. Winter aeration used to eliminate winterkill increased summer internal P loading and decreased water quality, while reductions in upstream beaver impoundments had little effect on water quality. Variations in air temperature and precipitation affected each basin differently. Warmer air temperatures increased productivity throughout the lake and decreased clarity in less eutrophic basins. Increased precipitation increased P in the basins intercepting the main flow but had little effect on the isolated deep West Bay. These relations are used to project effects of future climatic changes on LSG and other temperate lakes.

Analysis of Long-term Changes of Days with 25℃ or Higher Air Temperatures in Jeju

2016 ◽  
Vol 7 (1) ◽  
pp. 31 ◽  
Author(s):  
Jae-Won Choi ◽  
Yumi Cha ◽  
Jeoung-Yun Kim ◽  
Cheol-Hong Park
Keyword(s):  
Air Temperatures ◽  
Long Term Changes

Long Term Monitoring of the Macrobenthos of the Upper Clyde Estuary

1984 ◽  
Vol 16 (5-7) ◽  
pp. 359-373 ◽  
Author(s):  
Anne R Henderson
Keyword(s):  
Water Quality ◽  
Seasonal Variation ◽  
Organic Pollution ◽  
Long Term Changes ◽  
Pollution Loading ◽  
Faunal Density ◽  
History Of ◽  
Long Term Monitoring ◽  
Term Monitoring

The sublittoral macrobenthic invertebrate populations of the Upper Clyde Estuary are described. The estuary has a long history of organic pollution. The long term changes in species composition, faunal density and dominance patterns between 1974 and 1980 are presented. The fauna is dominated by brackish, pollution tolerant oligochaetes and polychaetes. Fluctuations in populations can be related to both seasonal variation in environmental conditions and long term improvements in water quality through a reduction in pollution loading to the estuary.

scholarly journals The consequences for stream water quality of long-term changes in landscape patterns: Implications for land use management and policies

2021 ◽  
Vol 109 ◽  
pp. 105679
Author(s):  
António Carlos Pinheiro Fernandes ◽  
Lisa Maria de Oliveira Martins ◽  
Fernando António Leal Pacheco ◽  
Luís Filipe Sanches Fernandes
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Stream Water ◽  
Landscape Patterns ◽  
Land Use Management ◽  
Stream Water Quality ◽  
Long Term Changes

Long-term changes in water quality and ecological status of lakes in the Wielkopolska National Park and its buffer zone with special reference to effectiveness of the lakes’ protection

2016 ◽  
Vol 45 (4) ◽  
Author(s):  
Agnieszka E. Ławniczak
Keyword(s):  
Water Quality ◽  
Catchment Area ◽  
National Park ◽  
Ecological Status ◽  
Buffer Zone ◽  
Field Studies ◽  
Long Term Changes ◽  
Protection Strategies

AbstractThis paper evaluates water quality and ecological status of lakes located in the Wielkopolska National Park and its buffer zone. Changes in water quality were analyzed from 1974 to 2012 in order to assess the effectiveness of the protection strategies implemented on the studied lakes since 1957, i.e. the date when the park was established. The ecological status of the lakes was assessed with the use of macrophytes as well as hydromorphological and physicochemical analyses performed in 2012. Changes in water quality of the studied lakes within the last 40 years were analyzed based on available published and unpublished data, as well as field studies. All water bodies are characterized by advanced eutrophication. However, evaluation of the ecological status showed good status of the charophyte-dominated lakes, i.e. Lake Wielkowiejskie and Lake Budzyńskie. Lack of significant differences in physicochemical water qualities between the park and its buffer zone indicated that measures implemented to protect the water, particularly in the park, are ineffective. This study shows that more radical conservation measures are necessary to protect and improve the water quality, not only in WPN and its buffer zone but also in the whole catchment area.

scholarly journals Long-term temperature and precipitation trends at the Coweeta Hydrologic Laboratory, Otto, North Carolina, USA

2012 ◽  
Vol 43 (6) ◽  
pp. 890-901 ◽  
Author(s):  
Stephanie H. Laseter ◽  
Chelcy R. Ford ◽  
James M. Vose ◽  
Lloyd W. Swift
Keyword(s):  
North Carolina ◽  
Global Climate ◽  
Forest Health ◽  
Monitoring Network ◽  
Drought Severity ◽  
Temperature And Precipitation ◽  
Air Temperatures ◽  
Precipitation Record ◽  
Coweeta Hydrologic Laboratory

Coweeta Hydrologic Laboratory, located in western North Carolina, USA, is a 2,185 ha basin wherein forest climate monitoring and watershed experimentation began in the early 1930s. An extensive climate and hydrologic network has facilitated research for over 75 years. Our objectives in this paper were to describe the monitoring network, present long-term air temperature and precipitation data, and analyze the temporal variation in the long-term temperature and precipitation record. We found that over the period of record: (1) air temperatures have been increasing significantly since the late 1970s, (2) drought severity and frequency have increased with time, and (3) the precipitation distribution has become more extreme over time. We discuss the implications of these trends within the context of regional and global climate change and forest health.

Long-term Changes of Physicochemical Water Quality in Lake Youngrang, Korea

2017 ◽  
Vol 50 (1) ◽  
pp. 169-185 ◽  
Author(s):  
Bal Dev Bhattrai ◽  
Sungjin Kwak ◽  
Kwansoon Choi ◽  
Woomyung Heo
Keyword(s):  
Water Quality ◽  
Long Term Changes

scholarly journals Climatic-change implications from long-term (1823-1994) ice records for the Laurentian Great Lakes

1995 ◽  
Vol 21 ◽  
pp. 383-386 ◽  
Author(s):  
R.A. Assel ◽  
D.M. Robertson ◽  
M.H. Hoff ◽  
J.H. Selgeby
Keyword(s):  
Great Lakes ◽  
Climatic Changes ◽  
The Other ◽  
Laurentian Great Lakes ◽  
Great Lakes Region ◽  
Lake Mendota ◽  
Air Temperatures ◽  
The 1960S ◽  
Different Parts

Long-term ice records (1823-1994) from six sites in different parts of the Laurentian Great Lakes region were used to show the type and general timing of climatic changes throughout the region. The general timing of both freeze-up and ice loss varies and is driven by local air temperatures, adjacent water bodies and mixing, and site morphometry. Grand Traverse Bay and Buffalo Harbor represent deeper-water environments affected by mixing of off-shore waters; Chequamegon Bay, Menominee, Lake Mendota, and Toronto Harbor represent relatively shallow-water, protected environments. Freeze-up dates gradually became later and ice-loss dates gradually earlier from the start of records to the 1890s in both environments, marking the end of the “Little lce Age”. After this, freeze-up dates remained relatively constant, suggesting little change in early-winter air temperatures during the 20th century. Ice-loss dates at Grand Traverse Bay and Baffalo Harbor but not at the other sites became earlier during the 1940s and 1970s and became later during the 1960s. The global warming of the 1980s was marked by a trend toward earlier ice-loss dates in both environments.

scholarly journals Identification of possible dynamical drivers for long-term changes in temperature and rainfall patterns over Europe

2020 ◽  
Vol 143 (1-2) ◽  
pp. 177-191
Author(s):  
Peter Hoffmann ◽  
Arne Spekat
Keyword(s):  
Decadal Variability ◽  
Meteorological Data ◽  
Weather Type ◽  
Seasonal Rainfall ◽  
Weather Types ◽  
Temperature And Precipitation ◽  
Long Term Changes ◽  
Rainfall Patterns ◽  
Climate Station

AbstractThis study looks into the question to what extent long-term change patterns of observed temperature and rainfall over Europe can be attributed to dynamical causes, in other words: Are the observed changes due to a change in frequency of the patterns or have the patterns’ dynamical properties changed? By using a combination of daily meteorological data and a European weather-type classification, the long-term monthly mean temperature and precipitation were calculated for each weather-type. Subsequently, the observed weather-type sequences were used to construct analogue time series for temperature and precipitation which only include the dynamical component of the long-term variability since 1961. The results show that only a fraction of about 20% of the past temperature rise since 1990, which for example amounted to 1 °C at the Potsdam Climate Station can be explained by dynamical changes, i.e. most of the weather-types have become warmer. Concerning long-term changes of seasonal rainfall patterns, a fraction of more than 60% is considerably higher. Moreover, the results indicate that for rainfall compared with temperature, the decadal variability and trends of the dynamical component follow the observed ones much stronger. Consequently, most of the explained seasonal rainfall variances can be linked to changes in weather-type sequences in Potsdam and over Europe. The dynamical contribution to long-term changes in annual and seasonal rainfall patterns dominates due to the fact that the alternation of wet and dry weather-types (e.g. the types Trough or High pressure over Central Europe), their frequencies and duration has significantly changed in the last decades.

scholarly journals Atmospheric stilling and warming air temperatures drive long‐term changes in lake stratification in a large oligotrophic lake

2020 ◽  
Author(s):  
Jonathan T. Stetler ◽  
Scott Girdner ◽  
Jeremy Mack ◽  
Luke A. Winslow ◽  
Taylor H. Leach ◽  
...  
Keyword(s):  
Oligotrophic Lake ◽  
Air Temperatures ◽  
Long Term Changes ◽  
Lake Stratification
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