Lake Level Dynamics Research Articles

A hybrid data-driven approach to analyze the drivers of lake level dynamics

A hybrid data-driven approach to analyze the drivers of lake level dynamics

Lake level dynamics in the centre of the East European Plain during the Holocene

Based on the lithostratigraphic and geomorphological approach, the study of lake level fluctuations in Nero and Seliger over the past 15,000 years was conducted. Common features of level changes were revealed: deep regression at the end of the late glacial period and early Holocene, intensive rise in level in the early-middle Holocene, stabilization (with a slight upward trend) in the late Holocene. Similar features in level changes were revealed in the history of a number of lakes in Germany and Scandinavia. A connection was found between lake level fluctuations and the intensity of fluvial processes in the center of the East European Plain.

Chironomid-based reconstruction of 500-year water-level changes in Daihai Lake, northern China

In recent decades, lakes in arid and semi-arid regions of northern China have been rapidly shrinking, threatening the area’s ecological security. However, the impacts of climate change and human activities on lake shrinkage remains unclear due to short instrumental records and a lack of long-term lake-level change records. To address this issue, we reconstructed the water depth changes of Daihai Lake, a typical lake experiencing rapid shrinkage in northern China, over the last 500 years using lake-level-sensitive chironomid assemblages. We established a regional quantitative transfer function of chironomid water-depth using 54 surface sediments from Daihai Lake and Bosten Lake in northern China. The partial least squares (PLS) model yielded a coefficient of determination (R2jack) of 0.85, a maximum bias of 1.75 m, and a root mean square error prediction (RMSEP) of 1.58 m demonstrating the reliability of inferred water depth. Several diagnostic methods were used to verify the results, and they were compared with a 60-years instrumental record. The reconstructed data revealed that the lake level was low during 1500–1780 CE, gradually increasing to its peak in the 1960s and then rapidly decreasing by approximately 10 m in the last few decades. By comparing the results with regional historical documents, palynology and stalagmite records, and meteorological data, we concluded that climate change was the main driver of lake level dynamics before the 1960s, while human activities dominated the rapid shrinkage of the lake in recent decades. Our results provide a valuable limnological dataset for the water management in Daihai Lake and a reliable method for reconstruct the lake-level changes.

On the capabilities of the SWOT satellite to monitor the lake level change over the Third Pole

The lake level dynamics of the Qinghai–Tibetan Plateau (QTP, also called the ‘Third Pole’) are a crucial indicator of climate change and human activities; however, they remain poorly measured due to extremely high elevation and cold climate. The existing satellite altimeters also suffer from relatively coarse temporal resolution or low spatial coverage, preventing effective monitoring of lake level change at such a large spatial scale. The recently launched surface water and ocean topography (SWOT) mission is expected to greatly enhance the current lake level monitoring capabilities. However, a systematic evaluation is still lacking in the region. To elucidate this potential, here, we generated SWOT-like lake products for 38 major lakes (>150 km2) over the QTP during 2000–2018 using a large-scale SWOT hydrology simulator with the input of satellite altimetry and water mask databases. The comparative assessments between the satellite altimetry data and SWOT simulations using various statistical metrics and decomposed time series components demonstrate that SWOT can successfully monitor both short-term dynamics and long-term trends. Extended experiments to derive SWOT-like data of 783 lakes (>1 km2) based on the synthetic lake level series present the spatial pattern of SWOT performance that tends to improve with the increasing lake area. Our findings provide comprehensive inferences and confidence for lake level monitoring in the Third Pole in the early period of the SWOT satellite.

Deciphering Hulun lake level dynamics and periodical response to climate change during 1961–2020

Study Region:Hulun Lake, the fifth largest lake in China. Study Focus:The notable decline in water level (WL) caused by climate change is the primary challenge faced by Hulun Lake. However, the contribution of climate to water loss and its driving mechanisms remain unclear. The impact of climate on WL change was investigated using wavelet analysis and structural equation models. New Hydrological Insights for the Region:In the past 60 years, the increasing potential evapotranspiration (ETp) caused by warming climate was the main reason for the WL decline (r=−0.67). For period I (1961–1997), reduced runoff due to increasing ETp caused an overall decrease in WL (r = 0.41). During the mid-1980s, the increase in rainfall driven by ENSO (r = −0.66) caused a slight increase in WL (r = 0.31). For period II (1998–2020), deforestation, farmland and urban area expansion were the main drivers behind the significant increase of ETp in the watershed (r = −0.22), which leads to reduced runoff and, consequently, a significant decrease in WL. The influence of climate on WL change weakened compared with that in the first period due to land use change (r = −1.08).

A 1,400-year eolian dust activity record from Lake Erhai in the northeastern Tibetan Plateau

Dust raised from Arid Central Asia (ACA) affects the global climate, global biogeochemical cycles, and human health. Studies on the ACA dust activities thus are crucial for understanding dust forcing mechanisms and the mitigation of hazardous storms. Located at the downwind margin of the ACA, the Lake Qinghai basin is an ideal trap for dust activities documentation. However, isolating eolian dust signals from Lake Qinghai sediments is difficult as the dust signals are well-mixed with riverine input signals. As a satellite of Lake Qinghai, Lake Erhai is much smaller and has only one inflow river. Lake Erhai, therefore, is much less sensitive to riverine input and its sediments theoretically contain more explicit dust signals. In this study, a 111.5-cm core was taken from Lake Erhai in 2016. The sediments’ grain size distribution (GSD) of this core was analyzed, and end-member (EM) analyses were applied to the GSDs to detect dust signals. Sediment carbonate content and carbonate oxygen isotopes (δ18Ocarb) were also measured to provide independent climate background information. Our results showed that the first EM is attributed to lake level dynamics due to its resemblances with carbonate content and δ18Ocarb records; the third EM, which peaked in the coarser grain size, is attributed to the riverine input; the remaining second EM likely captures the changes of regional dust activity and suggests that the Lake Qinghai basin has experienced multiple intense eolian dust activity intervals, i.e., 1000–1110, 1180–1290, and 1450–1560 AD over the past 1400 years. A further comparison of EMs with well-established climatic records in the northeastern Tibetan Plateau suggests that the rise and fall of regional dust activities are likely mainly controlled by wetness conditions and are secondarily affected by human activities.

Precipitation dynamics on the Tibetan Plateau during the Late Quaternary – Hydroclimatic sedimentary proxies versus lake level variability

Two of the largest and deepest endorheic lakes on the Tibetan Plateau, Nam Co and Tangra Yumco, were targeted to infer Late Quaternary (24 ka) responses of their hydrological balance to environmental dynamics. For this purpose, high-resolution multi-proxy records were used to obtain information on lake level variations and how these are related to direct precipitation proxies. Allochthonous minerogenic input as reflected by potassium (K), is directly linked to precipitation driven by variations in Indian Summer Monsoon. Negatively correlated elements such as Ca, Sr and Mg and associated carbonate mineral phases represent autochthonous sediment production, which is coupled to evaporation in these closed systems. δ 13 C and δ 18 O of bulk carbonates represent lake water conditions, i.e., salinity and lake water volume, interpreted as precipitation-evaporation (P/E) balance. In combination with geomorphological features, i.e., lake level terraces and paleo-shorelines, the multy-proxy data set from Nam Co is used to reconstruct lake level dynamics. Low lake levels of >90 m below the recent one between 20 and 16 ka cal BP are associated with most enriched δ 18 O carb values and the precipitation of aragonite and high-Mg calcite in a shallow lake with highly dynamic allochthonous minerogenic input. Similar conditions are observed between 13.1 and 11.4 ka cal BP matching the Younger Dryas chronozone. Between 15.5 and 13.1 ka cal BP as well as during the Early Holocene (11.4 to 8.0 ka cal BP) distinctly depleted δ 18 O carb and δ 13 C carb coupled with high rates of allochthonous minerogenic input suggest substantial strengthening in precipitation. After 9.4 ka cal BP, the terrigenous input and thus precipitation is significantly reduced, whereas δ 18 O carb reveals only a slight enrichment trend and thus a slowly but steady decrease in lake level througout the Mid- to Late Holocene. The decoupling of this relation between precipitation and lake level suggest that lake level terraces of large endorheic lakes on the TP and also δ 18 O carb records are not a direct indicator of (monsoonal) precipitiation, whereas the allochtonous minerogenic input can be directly linked to precipitation dynamics. This is supported by the comparison to regional archives from the Arabian Sea and the northern Bay of Bengal, showing the very same pattern in precipitation variability. The presented monsoon precipitation record from Nam Co additionally reveals a link to supra-regional atmospheric circulation components as it is oscillating in- and anti-phase to El-Niño strength and frequency. A distinct precipitation change at 2 ka cal BP seems to have affected all archives, however leaving space for future studies to find the cause of this Late-Holocene climatic shift. • First Late Quaternary lake level reconstruction for Nam Co, one of the best and most investigated lakes on the TP • Presentation of a robust paleo-precipitation proxy, i.e., allochthonous minerogenic input into the Tibetan lakes • Decoupling of lake level and precipitation proxy suggests e.g., paleo shorelines do not trace paleo-monsoonal variability • Robustness of the paleo-precipitation proxy supported by excellent temporal match of the variability to regional archives • Supra-regional link between paleo-precipitation on the Tibetan Plateau and the Tropical Pacific (El Niño variability)

Lake level dynamics exploration using deep learning, artificial neural network, and multiple linear regression techniques

Estimating the lake level dynamics accurately on a daily or finer timescale is important for a better understanding of ecosystems, especially the lakes in Badain Jaran Desert, China. In this study, lake level dynamics of Sumu Barun Jaran are simulated and predicted on a 2-h timescale using the deep learning (DL) model, which is structured for the first time in this area by considering critical environmental factors. Two machine learning methods, namely multiple linear regression (MLR) and the three-layered back-propagation artificial neural network (ANN), are also adopted for the prediction purpose. The performances of these models are evaluated by comparing the values of average relative error, the mean squared error, and the coefficient of determination. The result shows that the DL model performs better than MLR and ANN on these three criteria, and this DL model is beneficial for exploring the mechanism of lake level dynamics in Badain Jaran Desert.

Multi-decadal lake-level dynamics in north-eastern Germany as derived by a combination of gauging, proxy-data and modelling

In the glacially formed landscape of north-eastern Germany pronounced hydrological changes have been detected in recent decades, leading to the general question how lake levels and related groundwater levels perform in a long-term perspective, i.e. during the last c. 100 years. But long-term lake-level records are rare; most observations do not start before the late 20th century. Therefore, the potential of historic hydrological data, comprising drowned trees (as a geo-/bioarchive) and aerial as well as map imagery (as a document archive) was tested in order to derive discrete-time lake-level stands. These data are contrasted with lake-level simulations, obtaining a continuous-time series. Two small glacial lakes without connection to the stream network (i.e. closed lakes) were investigated in the Schorfheide area, c. 70 km north of Berlin. Both are dominantly fed by groundwater and precipitation but differ in their hydrogeological and catchment characteristics. For one lake a c. 40 year-long gauging record is available, showing high lake levels in the 1980s followed by a lowering of c. 3 m till the mid-2000s. In both lakes submerged in situ tree remains were discovered and dated by dendrochronology, revealing low lake levels during the first half of the 20th century. One lake was almost completely dry until c. 1960. Aerial photos provided data on lake levels since the 1930s which are corroborated by evidence of topographic mapping. Combining the empiric data with retrograde lake-level modelling, a well-proven lake-level record can be established for one lake that covers the last c. 90 years. The same general lake-level dynamics could be reconstructed by means of proxy data for the other lake. In both cases climate has been the dominant driver of lake-level dynamics. Comparisons with other multi-decadal lake-level records from the region show that these differ, depending on the hydrological lake type which modifies water feeding and water level. The results clearly showed that lake levels exhibited substantial long-term changes that should be taken into account in future hydroclimatic and hydrological studies.

Littoral landforms and pedosedimentary sequences indicating late Holocene lake-level changes in northern central Europe — A case study from northeastern Germany

A multidisciplinary study was carried out at Lake Großer Fürstenseer See (LFS) in order to explore the potential of littoral sediments, palaeosols and landforms as indicators of historical lake-level changes. This research was initiated to investigate the extent to which lakes in northern central Europe responded hydrologically to climatic and land-use changes in the last millennium. Specific landforms investigated comprise lake terraces, beach ridges, local basins/peatlands and dunes, revealing a wealth of sedimentary sub-environments at the lakeshore. Eleven sections were recorded with subsequent sedimentological–pedological, geochronological (OSL, 14C) and palaeobotanical (pollen, macro remains) analyses. Most of the pedosedimentary littoral sequences show a succession of basal glacial sand, intermediate palaeosols and lacustrine sand on top. A broader number of (semi-)terrestrial buried palaeosols along the lakeshore were systematically identified and analysed, providing evidence for changing hydrological conditions during the late Holocene. Additional historical data from the last centuries (e.g. maps, aerial photos, public records) allow the lake-levels reconstructed from geoarchives to be connected with modern gauging data. All local data sources available enable a tracing of lake level changes of the LFS during the last millennium, comprising periods of relatively low (c. 1200AD, 2000s AD) and relatively high water levels (c. 1250–1450AD, c. 1780AD, 1980s AD). The amplitude of lake-level changes during the last c. 1000years amounts to c. 3m, so that the fluctuations of the last 30years recorded by lake-level monitoring only reflect a small amount of the potential variability. Regional climate and local land-use history suggest that the Medieval lake-level dynamics of LFS were primarily governed by climate and secondarily influenced by human impact on the drainage system. At present the lake level is additionally influenced by the impact of highly water-consuming pine plantations in the catchment area. The regional significance of the local development at LFS can be demonstrated by comparison with other regional and supra-regional lake-level data. The present study underlines the potential of a closer examination of the littoral zone for lake-level reconstructions with high altitudinal precision.

Detection and attribution of lake-level dynamics in north-eastern central Europe in recent decades

The lake-rich glacial landscapes of north-eastern central Europe play an important role in the preservation and use of water resources, including protection of biodiversity, carbon storage and promotion of tourism. With a view to the last c. 20 years and the future, a regional ‘syndrome of water shortage’ has been frequently stated, which impairs particularly peatlands, flowing waters and lakes. Accordingly, the overall question addressed in this study is: What can regional and local gauging records tell us about decadal hydrological changes of lakes and their catchments? In the study area, most of the gauging records of lakes begin only in the late 1990s. Forty-five lake-level records were analysed by hierarchical agglomerative clustering, looking for the trend in the 1999–2008 time window. The analyses show that lake levels had varying dynamics, namely a negative, unclear or even a positive trend. The proportional shares of these three groups are 23 (51 %) to 15 (34 %) to 7 lakes (15 %), respectively. In group 1, largely groundwater-fed lakes, lake-level changes depend on groundwater-level changes. These are controlled by decreasing groundwater recharge in the catchments, which are caused by specific seasonal weather conditions in the observation period, and the impact of the dominating pine forests, which consume high quantities of water. In group 2, mainly stream lakes, direct human impact drives the lake levels through the management of weirs and ground sills. Nearly all lakes in group 3, consisting of river, stream and spring lakes, were subject to impoundment measures initiated by local rewetting projects. Thus, an important finding with respect to the impact of climate and land use is the fact that the (‘natural’) lakes of the region, primarily fed by groundwater and precipitation, show a predominantly negative lake-level trend in the period studied. Beyond the 10-year-time window analysed, further regional data show that periodic lake-level fluctuations with amplitudes of c. 1–2(–3) m are characteristic for regional groundwater-fed lakes.

Late Holocene lake level dynamics inferred from magnetic susceptibility and stable oxygen isotope data: Lake Elsinore, southern California (USA)

Southern California faces an imminent freshwater shortage. To better assess the future impact of this water crisis, it is essential that we develop continental archives of past hydrological variability. Using four sediment cores from Lake Elsinore in Southern California, we reconstruct late Holocene (� 3800 calendar years B.P.) hydrological change using a twentieth-century calibrated, proxy methodology. We compared magnetic susceptibility from Lake Elsinore deep basin sediments, lake level from Lake Elsinore, and regional winter precipitation data over the twentieth century to calibrate the late Holocene lake sediment record. The comparison revealed a strong positive, first-order relationship between the three variables. As a working hypothesis, we suggest that periods of greater precipitation produce higher lake levels. Greater precipitation also increases the supply of detritus (i.e., magnetic-rich minerals) from the lake's surrounding drainage basin into the lake environment. As a result, magnetic susceptibility values increase during periods of high lake level. We apply this modern calibration to late Holocene sediments from the lake's littoral zone. As an independent verification of this hypothesis, we analyzed � 18 O(calcite), interpreted as a proxy for variations in the precipitation:evaporation ratio, which reflect first order hydrological variability. The results of this verification support our hypothesis that magnetic susceptibility records regional hydrological change as related to precipitation and lake level. Using both proxy data, we analyzed the past 3800 calendar years of hydrological variability. Our analyses indicate a long period of dry, less variable climate between 3800 and 2000 calendar years B.P. followed by a wet, more variable climate to the present. These results suggest that droughts of greater magnitude and duration than those observed in the modern record have occurred in the recent geological past. This conclusion presents insight to the potential impact of future droughts on the over-populated, water-poor region of Southern California.

ABSTRACT: The Role of Lake Level Dynamics in Lacustrine Stratal Architecture and Sequence Development: Evidence from The Songwe Delta, Lake Malawi, East Africa

ABSTRACT: The Role of Lake Level Dynamics in Lacustrine Stratal Architecture and Sequence Development: Evidence from The Songwe Delta, Lake Malawi, East Africa

Carbonate deposition, Pyramid Lake Subbasin, Nevada: 4. Comparison of the stable isotope values of carbonate deposits (tufas) and the Lahontan lake-level record

In this paper, the fundamental importance of changes in hydrologic balance and hydrologic state on the δ 18O and δ 13C values of water and dissolved inorganic carbon (DIC) in lakes of the Lahontan basin is illustrated. Abrupt changes in δ 18O and δ 13C values of carbonate deposits (tufas) from the Pyramid Lake subbasin, Nevada, coincide with abrupt changes in lake-level and hydrologic state. Minima in lake-level at ∼26,000, ∼15,500 and ∼12,000 yr B.P. are associated with relatively heavy δ 18O and δ 13C values; maxima in the lake-level record at ∼14,000 and ∼10,500 yr B.P. are associated with relatively light δ 18O and δ 13C values. We believe that the correlation between maxima and minima in the lake-level and δ 18O records reflect the fundamental effect of lake-level dynamics on the δ 18O value of lake water. Evaporation increases the δ 18O value of lake water, whereas, streamflow discharge and on-lake precipitation decrease the δ 18O value. Variation in the δ 18O value of lake water, therefore, indicates change in the hydrologic balance; increases in δ 18O accompany decreases in lake volume and decreases in δ 18O accompany increases in lake volume. Covariance of δ 13C and δ 18O indicates that change in δ 13C values of DIC also accompany change in lake volume. We offer the hypothesis (first put forward by J.A. McKenzie) that change in the productivity (photosynthesis) respiration balance is responsible for much of the observed variation in δ 13C. Most Great Basin lakes, including Lake Lahontan, experienced changes in hydrologic state during the late Wisconsin. When a lake becomes hydrologically open, the residence time of water decreases. The greater the rate of spill, the greater the volume of evaporated ( 18O-enriched) water removed from the spilling lake and the more negative the δ 18O value of water remaining in the spilling lake. The concentration of DIC, as well as the concentrations of photosynthesis limiting nutrients (e.g., phosphorus, nitrogen, silica, molybdenum) decrease as spill increases. Increasing rates of spill, therefore, lead to overall decreases in photosynthetic rates relative to respiration rates and, as a consequence, the δ 13C values of DIC become more negative.

Deposition of modern pollen and plant macroremains in a hypersaline prairie lake basin

Comparisons between current vegetation patterns and deposition of modern pollen and plant macroremains in a saline lake basin on the northern Great Plains are used to assess the value of plant remains as indicators of past local vegetation dynamics and lake-level changes. Results indicate that both modern pollen spectra and assemblages of plant macroremains reflect clearly the composition of the local vegetation, whereas plant macroremains best reflect lake size. Cactaceae pollen and seeds are confined to upland prairie deposits. Liguliflorae (Compositae) and Leguminosae pollen, Selaginella densa microspores, and Euphorbia and Cruciferae seeds are more abundant in prairie upland deposits than in shoreline or lacustrine environments. An abundance (> 50%) of Ruppia pollen distinguishes near-shore lake sediments, indicating that this taxon is a useful marker of shallow shoreline environments in saline lakes. Seeds of Chenopodiaceae, Erigeron, Cruciferae, and Cyperaceae, as well as Chara oogonia, are more abundant in near-shore lacustrine sediments than in the central lake area, suggesting that they too are indicators of shoreline proximity. These data are useful for paleobotanical reconstructions of past lake-level dynamics. Key words: saline lakes, Great Plains, pollen, paleobotany, paleohydrology, environmental reconstruction.