scholarly journals Discussion of the climatic change in recent 600 years and dropping of lake water-level, Qinghai Lake drainage basin

1992 ◽  
Vol 4 (3) ◽  
pp. 25-31 ◽  
Author(s):  
Zhou Lusheng ◽  
◽  
Yang Weidong
2020 ◽  
Vol 141 (3-4) ◽  
pp. 1285-1300 ◽  
Author(s):  
Zaher Mundher Yaseen ◽  
Shabnam Naghshara ◽  
Sinan Q. Salih ◽  
Sungwon Kim ◽  
Anurag Malik ◽  
...  

2021 ◽  
pp. 126582
Author(s):  
Nawaraj Shrestha ◽  
Aaron Mittelstet ◽  
Aaron R. Young ◽  
Troy E. Gilmore ◽  
David C. Gosselin ◽  
...  

2021 ◽  
Vol 25 (3) ◽  
pp. 1643-1670
Author(s):  
Song Shu ◽  
Hongxing Liu ◽  
Richard A. Beck ◽  
Frédéric Frappart ◽  
Johanna Korhonen ◽  
...  

Abstract. A total of 13 satellite missions have been launched since 1985, with different types of radar altimeters on board. This study intends to make a comprehensive evaluation of historic and currently operational satellite radar altimetry missions for lake water level retrieval over the same set of lakes and to develop a strategy for constructing consistent long-term water level records for inland lakes at global scale. The lake water level estimates produced by different retracking algorithms (retrackers) of the satellite missions were compared with the gauge measurements over 12 lakes in four countries. The performance of each retracker was assessed in terms of the data missing rate, the correlation coefficient r, the bias, and the root mean square error (RMSE) between the altimetry-derived lake water level estimates and the concurrent gauge measurements. The results show that the model-free retrackers (e.g., OCOG/Ice-1/Ice) outperform the model-based retrackers for most of the missions, particularly over small lakes. Among the satellite altimetry missions, Sentinel-3 gave the best results, followed by SARAL. ENVISAT has slightly better lake water level estimates than Jason-1 and Jason-2, but its data missing rate is higher. For small lakes, ERS-1 and ERS-2 missions provided more accurate lake water level estimates than the TOPEX/Poseidon mission. In contrast, for large lakes, TOPEX/Poseidon is a better option due to its lower data missing rate and shorter repeat cycle. GeoSat and GeoSat Follow-On (GFO) both have an extremely high data missing rate of lake water level estimates. Although several contemporary radar altimetry missions provide more accurate lake level estimates than GFO, GeoSat was the sole radar altimetry mission, between 1985 and 1990, that provided the lake water level estimates. With a full consideration of the performance and the operational duration, the best strategy for constructing long-term lake water level records should be a two-step bias correction and normalization procedure. In the first step, use Jason-2 as the initial reference to estimate the systematic biases with TOPEX/Poseidon, Jason-1, and Jason-3 and then normalize them to form a consistent TOPEX/Poseidon–Jason series. Then, use the TOPEX/Poseidon–Jason series as the reference to estimate and remove systematic biases with other radar altimetry missions to construct consistent long-term lake water level series for ungauged lakes.


2020 ◽  
Vol 77 (11) ◽  
pp. 1836-1845
Author(s):  
K. Martin Perales ◽  
Catherine L. Hein ◽  
Noah R. Lottig ◽  
M. Jake Vander Zanden

Climate change is altering hydrologic regimes, with implications for lake water levels. While lakes within lake districts experience the same climate, lakes may exhibit differential climate vulnerability regarding water level response to drought. We took advantage of a recent drought (∼2005–2010) and estimated changes in lake area, water level, and shoreline position on 47 lakes in northern Wisconsin using high-resolution orthoimagery and hypsographic curves. We developed a model predicting water level response to drought to identify characteristics of the most vulnerable lakes in the region, which indicated that low-conductivity seepage lakes found high in the landscape, with little surrounding wetland and highly permeable soils, showed the greatest water level declines. To explore potential changes in the littoral zone, we estimated coarse woody habitat (CWH) loss during the drought and found that drainage lakes lost 0.8% CWH while seepage lakes were disproportionately impacted, with a mean loss of 40% CWH. Characterizing how lakes and lake districts respond to drought will further our understanding of how climate change may alter lake ecology via water level fluctuations.


Fluids ◽  
2019 ◽  
Vol 4 (4) ◽  
pp. 182 ◽  
Author(s):  
Seema Paul ◽  
Jesper Oppelstrup ◽  
Roger Thunvik ◽  
John Mango Magero ◽  
David Ddumba Walakira ◽  
...  

This study explored two-dimensional (2D) numerical hydrodynamic model simulations of Lake Victoria. Several methods were developed in Matlab to build the lake topography. Old depth soundings taken in smaller parts of the lake were combined with more recent extensive data to produce a smooth topographical model. The lake free surface numerical model in the COMSOL Multiphysics (CM) software was implemented using bathymetry and vertically integrated 2D shallow water equations. Validated by measurements of mean lake water level, the model predicted very low mean flow speeds and was thus close to being linear and time invariant, allowing long-time simulations with low-pass filtered inflow data. An outflow boundary condition allowed an accurate simulation to achieve the lake’s steady state level. The numerical accuracy of the linear measurement of lake water level was excellent.


1997 ◽  
Vol 15 (11) ◽  
pp. 1489-1497 ◽  
Author(s):  
M. Kadioğlu ◽  
Z. Şen ◽  
E. Batur

Abstract. Global warming resulting from increasing greenhouse gases in the atmosphere and the local climate changes that follow affect local hydrospheric and biospheric environments. These include lakes that serve surrounding populations as a fresh water resource or provide regional navigation. Although there may well be steady water-quality alterations in the lakes with time, many of these are very much climate-change dependent. During cool and wet periods, there may be water-level rises that may cause economic losses to agriculture and human activities along the lake shores. Such rises become nuisances especially in the case of shoreline settlements and low-lying agricultural land. Lake Van, in eastern Turkey currently faces such problems due to water-level rises. The lake is unique for at least two reasons. First, it is a closed basin with no natural or artificial outlet and second, its waters contain high concentrations of soda which prevent the use of its water as a drinking or agricultural water source. Consequently, the water level fluctuations are entirely dependent on the natural variability of the hydrological cycle and any climatic change affects the drainage basin. In the past, the lake-level fluctuations appear to have been rather systematic and unrepresentable by mathematical equations. Herein, monthly polygonal climate diagrams are constructed to show the relation between lake level and some meteorological variables, as indications of significant and possible climatic changes. This procedure is applied to Lake Van, eastern Turkey, and relevant interpretations are presented.


2018 ◽  
Vol 11 (1) ◽  
pp. 258-273 ◽  
Author(s):  
Tibebe B. Tigabu ◽  
Georg Hörmann ◽  
Paul D. Wagner ◽  
Nicola Fohrer

Abstract This research focuses on the statistical analyses of hydrometeorological time series in the basin of Lake Tana, the largest freshwater lake in Ethiopia. We used autocorrelation, cross-correlation, Mann–Kendall, and Tukey multiple mean comparison tests to understand the spatiotemporal variation of the hydrometeorological data in the period from 1960 to 2015. Our results show that mean annual streamflow and the lake water level are varying significantly from decade to decade, whereas the mean annual rainfall variation is not significant. The decadal mean of the lake outflow and the lake water level decreased between the 1990s and 2000s by 11.34 m3/s and 0.35 m, respectively. The autocorrelation for both rainfall and streamflow were significantly different from zero, indicating that the sample data are non-random. Changes in streamflow and lake water level are linked to land use changes. Improvements in agricultural water management could contribute to mitigate the decreasing trends.


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