Hydrological regime of Adygine lake, Tien Shan, Kyrgyzstan

This article provides a detailed analysis of the hydrological regime of the Adygine glacial lake in Tien Shan, Kyrgyzstan, and of the specific factors which affect it. Glaciers of central Tien Shan are considered to be very sensitive indicators of climate change. The studied lake belongs to a system of relatively recently formed lakes situated near the front of the retreating glacier and is numbered amongst the potentially dangerous. The lake’s water level and its dependence on the development of climatic conditions in the area were monitored in detail in 2007–2012. A substantial part of this paper is the evaluation of the inflow and outflow balance of the lake’s basin. The results confirmed that the hydrological regime is glacial and exhibits its typical characteristics, such as a seasonal evolution of runoff delay or significant diurnal fluctuation of the lake’s water level. During the monitored period, no major changes in annual lake level fluctuation were recorded.

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Lake level and trophic state variables among a population of shallow Florida lakes and within individual lakes

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f05-177 ◽

2005 ◽

Vol 62 (12) ◽

pp. 2760-2769 ◽

Cited By ~ 14

Author(s):

Mark V Hoyer ◽

Christine A Horsburgh ◽

Daniel E Canfield, Jr. ◽

Roger W Bachmann

Keyword(s):

Water Level ◽

Lake Level ◽

Trophic State ◽

Secchi Depth ◽

Water Level Fluctuation ◽

Water Level Fluctuations ◽

Level Fluctuation ◽

State Variables ◽

Florida Lakes ◽

Lake Level Fluctuation

Monthly total phosphorus, total nitrogen, and chlorophyll concentrations, Secchi depth, and lake water level data for 84 Florida lakes were used to examine relations between trophic state variables and water level fluctuation. Lake size averaged 566 ha (range 4.0 to 5609 ha), with the period of record for individual lakes averaging 57 months (range 7 to 175 months). Lake level fluctuation for individual lakes averaged 1.3 m (range 0.1 to 3.5 m). The lakes also ranged from oligotrophic to hypereutrophic, with average chlorophyll values for individual lakes ranging from 1 to 97 µg·L1. No overall relation between trophic state variables and lake level fluctuation could be found among the population of lakes. However, individual lakes showed direct, inverse, or no significant relations between lake trophic state variables and water level fluctuation, regardless of the magnitude of water level fluctuation. These data suggest that predicting how water level fluctuations will impact trophic state variables among a population of lakes will be difficult, if not impossible, and that any accurate predictions will have to be made after first examining several mechanisms within individual lake systems.

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Spatial and Temporal Dynamics of Water Hyacinth and Its Linkage with Lake-Level Fluctuation: Lake Tana, a Sub-Humid Region of the Ethiopian Highlands

Water ◽

10.3390/w12051435 ◽

2020 ◽

Vol 12 (5) ◽

pp. 1435 ◽

Cited By ~ 2

Author(s):

Minychl G. Dersseh ◽

Seifu A. Tilahun ◽

Abeyou W. Worqlul ◽

Mamaru A. Moges ◽

Wubneh B. Abebe ◽

...

Keyword(s):

Water Level ◽

Water Hyacinth ◽

Lake Level ◽

Temporal Dynamics ◽

Water Level Fluctuation ◽

Suitable Habitat ◽

Level Fluctuation ◽

Lake Tana ◽

Lake Level Fluctuation ◽

The Impact

Water hyacinth originated from the Amazon Basin and has expanded to other parts of the world since the 1800s. In Ethiopia, the weed is affecting the socio-economic activities of the people whose livelihood is directly or indirectly dependent on Lake Tana. Still, the area covered by water hyacinth and the impact of water level fluctuation on the expansion of water hyacinth has not been known clearly. Therefore, the main objective of this study was to determine the spatiotemporal distribution of water hyacinth and relation with lake-level fluctuation. The area covered by water hyacinth was determined using monthly Sentinel-2 images, which were collected from November 2015 to December 2019. The impact of water level fluctuation on the expansion of water hyacinth was evaluated using hourly water level data converted to a monthly average to correlate with the area covered by the water hyacinth. In addition, MOD13Q1.006 data was used to evaluate the trend of the Normalized Difference Vegetation Index (NDVI) and its linkage with the weed. The maximum areas covered by water hyacinth were 278.3, 613.6, 1108.7, 2036.5, and 2504.5 ha in Feb 2015, October 2016, September 2017, December 2018, and in December 2019, respectively. Its areal coverage was declining from the northern corridors and increasing in eastern shores of the lake. The lake-level fluctuation was observed in the range of 1.5 to 3.98 m in this study. The annual mean maximum spatial values of the NDVI were in the range of 0.27 and 0.47. The area covered by water hyacinth was increasing significantly (P < 0.05) and positively correlated with the seasonal lake-level fluctuation. High water level enabled the expansion of the weed by extending its suitable habitat of shallow water to the flood plain. Based on the results of this study, lake-level fluctuations can have an adverse impact on the expansion of the weed.

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