Lake Width Research Articles

Enhancing the temporal resolution of water levels from altimetry using D-InSAR: A case study of 10 Swedish Lakes

Lakes provide societies and natural ecosystems with valuable services such as freshwater supply and flood control. Water level changes in lakes reflect their natural responses to climatic and anthropogenic stressors; however, their monitoring is costly due to installation and maintenance requirements. With its advanced hardware and computational capabilities, altimetry has become a popular alternative to conventional in-situ gauging, although subject to the temporal availability of altimetric observations. To further improve the temporal resolution of altimetric measurements, we here combine radar altimetry data with Differential Interferometric Synthetic Aperture Radar (D-InSAR), using ten lakes in Sweden as a testing platform. First, we use Sentinel-1A and Sentinel-1B SAR images to generate consecutive six-day baseline interferograms across 2019. Then, we accumulate the phase change of coherent pixels to construct the time series of InSAR-derived water level anomalies. Finally, we retrieve altimetric observations from Sentinel-3, estimate their mean and standard deviation, and apply them to the D-InSAR standardized anomalies. In this way, we build a water-level time series with more temporal observations. In general, we find a strong agreement between water level estimates from the combination of D-InSAR and Satellite Altimetry (DInSAlt) and in-situ observations in eight lakes (Concordance Correlation Coefficient - CCC >0.8) and moderate agreement in two lakes (CCC >0.57). The applicability of DInSAlt is limited to lakes with suitable conditions for double-bounce scattering, such as the presence of trees or marshes. The accuracy of the water level estimates depends on the quality of the altimetry observations and the lake's width. These findings are important considering the recently launched Surface Water and Ocean Topography (SWOT) satellite, whose capabilities could expand our methodology's geographical applicability and reduce its reliance on ground measurements.

Characteristic and affecting factors of wetland herbs\u2019 distribution in the radiant belt toward land of lake\u2013terrestrial ecotone in Tibet, China

BackgroundLake is a critical part of Tibet's hydrological cycle, the lake–terrestrial ecotone is the most sensitive area in the water and terrestrial ecosystem. For the ecological protection and maintenance of the lakeside zone, defining the upper boundary of the lake–terrestrial ecotone is a key issue that needs to be solved urgently. However, the ecological characteristics of lake–terrestrial ecotone made it difficult to delimit. Wetland herbs are characteristic plants of the lake–terrestrial ecotone, and their distribution width can be used to reflect the upper boundary of the lake–terrestrial ecotone. We took Baksum Lake, Yamdroktso, Namtso, Siling Co as examples, based on the spatial structure of the lake–terrestrial ecotone, used the moving split-window technology (MSWT) delimited the width of wetland herbs.ResultsThe results of the MSWT showed the distribution width of wetland herbs in each lake–terrestrial ecotone with the natural-wetland type sampling line of Baksum Lake, Yamdroktso, Namtso, Siling Co was 51 m, 56 m, 33 ~ 53 m, 19 ~ 31 m. The detrended correspondence analysis (DCA) showed quantity of wetland herbs species, BK1 > YT1 = NT1 > NT2 > SC1 = SC2. The principal component analysis (PCA) and the (redundancy analysis) RDA showed soil moisture content (SMO), pH, soil moisture content (SSC), and soil nutrient content had obvious correlation with distribution width.ConclusionThe MSWT was a feasible method to determine the width of lake–terrestrial ecotone. SMO, pH, SSC, and soil nutrient content were all important environmental factors affecting the wetland herbs distribution width of the four lakes; and the SMO was the most important factor. Besides, compared with the lakes in the Middle-Lower Yangtze Plain, the high-density population distribution, high-intensive human activity invaded the plants' growth area, resulting in a smaller distribution width. The distribution edge of wetland herbs is equivalent to the upper boundary of lake–terrestrial ecotone. It determines the management boundary of the lake–terrestrial ecotone, provides a theoretical basis for the construction of environmental protection projects, and is of great significance to the lake ecological restoration and management in watershed control planning.

Southern coastal subtropical shallow lakes skin temperature driven by climatic and non-climatic factors.

Subtropical coastal shallow lakes (SCSL) are sensitive ecosystems. The lake-skin-water temperature (LSWT) is an average lake temperature proxy and responds to changes in surroundings, affecting biological and physical lake processes. In this study, M*D11A1 products are used to develop daytime and nighttime LSWT time series for 20 SCSL in South America. The influence of climatic (air temperature, surface net solar radiation, wind speed, and wind direction) and non-climatic (latitude, lake area, perimeter, width, length, and morphology) factors are evaluated from 2001 to 2017. Pearson's coefficients (ρ) and auto- and cross-correlations are used to establish the relation between LWST and the selected factors. We identify that the dynamic of LSWT is sensitive to geomorphological factors (latitude and lake width) throughout the year, especially in summer. In winter, the LSTW regime is mainly affected by wind direction (ρ = -0.66, p value < 0.01). Linear models are fitted to the temperature series to check the trend changes in the inflection points and the warming or cooling trend for LSWT. Considering the complete series, the maximum warming rate of LSWT is 0.25 °C per decade (°C/dec). The analysis of the identified sub-periods reveals that warming and cooling can occur (significantly) in shorter periods. The average trends within sub-periods for skin temperature-daytime (± 0.0105 °C/dec), skin temperature-nighttime (0.0041 °C/dec), and air temperature (- s0.006 °C/dec; 0.007 °C/dec) are estimated. Our approach has the potential to be applied in future studies due to the expansion of knowledge about the behavior of SCSL and the understanding of the current and potential effects of climate change in association with physical and geomorphological traits.

Glacial lake depth and volume estimation based on a large bathymetric dataset from the Cordillera Blanca, Peru

AbstractGlacial lakes are most often located in remote places making it difficult to carry out detailed bathymetric surveys. Consequently, lake depths and volumes for unmeasured lakes are often estimated using empirical relationships developed mainly from small bathymetric datasets. In this study, we use the bathymetry dataset of the Cordillera Blanca, Peru comprising 121 detailed lake bathymetries, the most extensive dataset in the world. We assess the performance of the most commonly applied empirical relationships for lake mean depth and volume estimation, but also investigate relationships between different geometric lake variables. We find that lake volume estimation performs better when derived from lake mean depth, which in turn is estimated from lake width. The findings also reveal the extreme variability of lake geometry, which depends on glacio‐geomorphological processes that empirical–statistical relationships cannot adequately represent. Such relationships involve characteristic uncertainty ranges of roughly ±50%. We also estimate potential peak discharges of outburst floods from these lakes by applying empirical relationships from the literature, which results in discharges varying by up to one‐order of magnitude. Finally, the results are applied to the 860 lakes without bathymetric measurements from the inventory dataset of the Cordillera Blanca to estimate lake mean depth, volume and possible peak discharge for all unmeasured lakes. Estimations show that ca. 70% (610) of the lakes have a mean depth lower than 10 m and very few longer than 40 m. Lake volume of unmeasured lakes represent ca. 32% (5.18 × 108 m3) of the total lake volume (1.15 × 109 m3) in the Cordillera Blanca. Approximately, 50% of the lakes have potential peak discharges &gt; 1000 m3/s in case of lake outburst floods, implying a need for additional studies for risk assessment. © 2020 John Wiley &amp; Sons, Ltd.

Preferences for a lake landscape: Effects of building height and lake width

Cities with lakes must balance the relationship between development and preservation of the natural landscape. Tall buildings are important in urban development, while landscape destruction and visual pollution caused by tall buildings have attracted more attention. Many qualitative or quantitative restrictions for building height have been designated along lakefronts. However, it is unclear whether the public accepts these restricted heights. This study aimed to assess the effects of building height and lake width on public preferences for lake landscapes. Two experiments were designed with two common lake scenarios. Three levels of building height crossed with three levels of lake width were presented in nine synthetic lake landscapes in each experiment, which were assessed by 50 participants using a psychological evaluation tool, namely the Affect Grid. The results showed that when lake width was within the Close View range with only trees on the other side of the lake, a lake landscape with the heights of buildings' visible part moderately less than average height of the trees contour was preferred over rigidly restricting that all buildings be barely visible. For lake landscapes with mountains in the background, it was found that a lake-wide threshold existed between 0.6 km and 1.8 km. Using this threshold, the Medium View range could be reclassified so that a lake width within this range might correspond to a particular type of building height restriction. These findings provide a reference for urban planners and suggest that lakes can be categorized on the basis of lake width and, in this category, building height can be restricted more appropriately.

Danau Laut Balbullol di Misool Raja Ampat

Danau laut adalah ekosistem unik yang ditemukan terfokus di empat lokasi saja di dunia. Salah satunya di Raja Ampat. Danau-danau tersebut memiliki karakter yang unik sesuai tingkat koneksinya dengan laut. Danau Balbullol adalah danau yang paling dalam diantara danau laut di Misool, terasing, dan belum pernah dikaji. Melalui studi ini ingin mengetahui karakter dari Danau Balbullol. Deskripsi danau dilakukan dengan serangkaian survei lapangan dan perekaman logger untuk mengetahui karakter fisik, kualitas air, dan kehadiran biota. Hasilnya diketahui luas danau adalah 1,94 ha dengan kedalaman maksimum 38 m. Suhu dan salinitas memperlihatkan profil vertikal yang homogen, sehingga membentuk tipe holomiktik. Selama 6 bulan time series dari rekaman logger, menunjukan suhu di danau selalu lebih panas dari pada di laut, demikian juga salinitas yang lebih salin di danau. Pasut di danau tertunda 4 jam daripada laut, walaupun jarak antara danau dan laut sangat dekat (&lt;45 m). Amplitudo pasut hanya 25% daripada laut. Walaupun dari hasil pengukuran pasut Danau Balbullol merupakan danau yang terisolasi, namun tidak ditemukan biota sebagai indikator danau terisolasi. Ditemukan minimal 7 karang lunak dengan atribut banyak dan melimpah di danau ini.

Lakemorpho: Calculating lake morphometry metrics in R

Metrics describing the shape and size of lakes, known as lake morphometry metrics, are important for any limnological study. In cases where a lake has long been the subject of study these data are often already collected and are openly available. Many other lakes have these data collected, but access is challenging as it is often stored on individual computers (or worse, in filing cabinets) and is available only to the primary investigators. The vast majority of lakes fall into a third category in which the data are not available. This makes broad scale modelling of lake ecology a challenge as some of the key information about in-lake processes are unavailable. While this valuable in situ information may be difficult to obtain, several national datasets exist that may be used to model and estimate lake morphometry. In particular, digital elevation models and hydrography have been shown to be predictive of several lake morphometry metrics. The R package lakemorpho has been developed to utilize these data and estimate the following morphometry metrics: surface area, shoreline length, major axis length, minor axis length, major and minor axis length ratio, shoreline development, maximum depth, mean depth, volume, maximum lake length, mean lake width, maximum lake width, and fetch. In this software tool article we describe the motivation behind developing lakemorpho, discuss the implementation in R, and describe the use of lakemorpho with an example of a typical use case.

Lakemorpho: Calculating lake morphometry metrics in R.

Metrics describing the shape and size of lakes, known as lake morphometry metrics, are important for any limnological study. In cases where a lake has long been the subject of study these data are often already collected and are openly available. Many other lakes have these data collected, but access is challenging as it is often stored on individual computers (or worse, in filing cabinets) and is available only to the primary investigators. The vast majority of lakes fall into a third category in which the data are not available. This makes broad scale modelling of lake ecology a challenge as some of the key information about in-lake processes are unavailable. While this valuable in situ information may be difficult to obtain, several national datasets exist that may be used to model and estimate lake morphometry. In particular, digital elevation models and hydrography have been shown to be predictive of several lake morphometry metrics. The R package lakemorpho has been developed to utilize these data and estimate the following morphometry metrics: surface area, shoreline length, major axis length, minor axis length, major and minor axis length ratio, shoreline development, maximum depth, mean depth, volume, maximum lake length, mean lake width, maximum lake width, and fetch. In this software tool article we describe the motivation behind developing lakemorpho, discuss the implementation in R, and describe the use of lakemorpho with an example of a typical use case.

Macrophyte diversity of lakes in the Pannon Ecoregion (Hungary)

We examined the distribution of submerged and emergent macrophyte species and the entire macrophyte community within and between five lake types (highland reservoirs, alkali lakes, large shallow lakes, small to medium sized shallow lakes, marshes) in the Pannon Ecoregion, Hungary. The lowest submerged, emergent and total species richness was found in alkali lakes. The highest submerged macrophyte richness was in small to medium sized lakes, while the highest emergent macrophyte species richness was in reservoirs, small to medium sized lakes, and marshes. The values of within-lake type beta diversity were generally lower than the values of alpha diversity, especially for submerged macrophytes, indicating between site homogeneity in species composition within the lake types. Emergent macrophyte communities contributed the most to within and between lake type diversity and total (gamma) diversity. Canonical correspondence analyses showed that the main environmental variables which influenced the distribution of submerged macrophytes were conductivity, Secchi transparency and water nitrogen contents. For emergent macrophytes conductivity, lake width, altitude and water depth proved to be the most influential variables. Our results contribute to the knowledge of large-scale distribution of macrophytes in the Pannon Ecoregion and to the identification of conservation value of lakes using macrophytes. The results support the importance of small lakes and artificial lakes in the conservation of macrophyte diversity compared to large and natural lakes in the Pannon Ecoregion.

Internal solitary waves in Upper Lake Constance

The conceptual hypothesis that internal solitary waves (ISWs) in lakes are generated at fronts of basin-scale internal waves, propagate until they break at the terminal boundary and extend over the lake width in cross-propagation direction is tested using temperature and current profiles measured in Upper Lake Constance. Trains of ISWs of depression propagate in close association with the front of a Kelvin wave at almost constant phase speed from the main basin of Upper Lake Constance to the western shore of a sub-basin, Lake Uberlingen. The trough of the ISWs extends over the entire basin width in narrow Lake Uberlingen but not in the wider main basin. A substantial part of the ISWs propagating towards the western terminal boundary did not return, suggesting wave-energy loss due to wave breaking. Close to the shorelines parallel to their propagation direction the amplitudes of the ISWs are diminished. Temperature inversions suggest that wave breaking is occurring at these boundaries, but also in the open water where breaking events extend along the width of the ISW front. The heterogeneity of ISW breaking suggests that the associated mixing and vertical fluxes of plankton and nutrients across the thermocline are highly variable in space and time.

Modeling experiment of break of debris-flow dam

Glaciers are extensively developed in the southwest of Tibet and the moraines are widely distributed with large depth. Large-scale debris flows are often reported which blocked rivers and formed dams. In this paper, seven large debris flows in four valleys are discussed, among which five dams developed. 13 sets of experiments have been conducted in laboratory to simulate the formation and failure of the dam. Finally, a model of dam failure is proposed and a formula is established to calculate the flood discharge: \(Q = k\frac{{b_h h_k }}{T}\frac{{\bar B}}{L}G^{0.41} \), where bk is the outlet width of the dam at the original water level, hk the erosive depth, T the time from overflow to final state of failure, the average width of lake; L the length of the lake, and G the total potential energy of the water in the lake.

Water Quantity and Quality of Mansar Lake Located in the Himalayan Foothills, India

Bathymetric survey and physico-chemical analysis of Mansar Lake, located in the Himalayan foothills in the state of Jammu and Kashmir, India, were carried out to assess water quantity and quality. The bathymetric survey indicated that Mansar Lake, with a surface area of 0.59 × 106 m2 at present outflow level, has a maximum depth, length and width of 38.25 m, 1204 m and 645 m, respectively. The lake mean width is 490 m, mean depth is 21 m, and mean slope of the lake floor is 0.14 m·m−1. The storage capacity of the lake up to present outflow level is 11.57 × 106 m3. Vertical variation of temperature, pH, electrical conductivity, dissolved oxygen, hardness and alkalinity suggest that Mansar Lake undergoes complete mixing during January and February and is stratified in other months. Calcium, magnesium and sodium are the dominant cations, and bicarbonate the dominant anion. Analysis of chemical parameters shows that the lake water is of Ca-Mg-HCO3-CO3 type. Phosphate concentration >0.03 mg·L−1 in the Mansar Lake water indicated that the lake is eutrophic. Suitable measures have been suggested for sustainable management of Mansar Lake.

Lake‐induced atmospheric circulations during BOREAS

Lake‐induced atmospheric circulations over three lakes ranging from 3 to 10 km width are analyzed using data from three aircraft during the 1994 Boreal Ecosystem‐Atmosphere Study (BOREAS). A well‐defined divergent lake breeze circulation is observed over all three lakes during the day. Under light wind conditions, the lake breeze is not very sensitive to the water temperature, and the strength of the divergence over the lake decreases with increasing lake size. The boundary‐layer development over the surrounding land can be very important for generating a horizontal pressure difference which drives the lake breeze. Diurnal and seasonal variations of lake breezes are investigated on the basis of repeated passes from the different aircraft at different altitudes from late spring to early fall of 1994. The lake breeze divergence increases with time during the day and reaches a maximum around 1300 LST. The latent heat flux over 10‐km‐wide Candle Lake increases steadily from spring to fall as the lake temperature increases. The latent heat flux over the land reaches a maximum during the summer due to evapotranspiration. The lake effect on area‐averaged fluxes sometimes leads to a negative heat transfer coefficient for an averaging scale of several times the lake width.

Small Lake Daytime Breezes: Some Observational and Conceptual Evaluations

Abstract The diversity of small lakes' (size <50 km) configurations, sizes, surrounding terrain, and land use combined with relative sparsity of observations complicates the observational evaluation of the lake breezes (LB) that are induced by these lakes. In the present article observational data obtained from available documents, data archives, and special projects were surveyed to suggest characterization of the LB features. The observational survey was complemented by conceptual evaluations. A preliminary generalization of the LB intensity and inland penetration in relation to the surrounding land use was inferred. The conceptual evaluation suggested that for a given lake width the prime factor affecting the LB intensity is the magnitude of the surface sensible heat flux over the surrounding land. Cooling related to the lake water temperature was indicated to have usually a secondary effect on the LB intensity for small lakes. Surface observations implied that the onshore penetration of the LB by the ...

Regional survey for He anomalies in Canadian shield lakes: sources of variation and implications for nuclear fuel waste management

Bottom-water He concentration (=[He]) was measured in the late summers of 1989, 1990 and 1991 in the waters of lake basins at the Experimental Lakes Area in northwestern Ontario, Canada. A total of 32 basins were sampled every year. Helium concentrations were relatively stable from year to year, exhibiting a mean coefficient of variation of 34%. Total [He] ranged from values below the atmospheric equilibrium concentration of 47 nl He/l H 2O to a maximum of 5364 nl/l measured in Lake 625 in 1991. Total [He] exhibited a two-phase distribution, with a large subpopulation of basins having only modest He enrichment (geometric mean G.M.= 77nl/l, geometric standard deviation G.S.D.= 1.65, n = 39), and a small subpopulation of basins, including Lakes 625, 634 and 615, with large He anomalies (G.M.= 692nl/l,G.S.D.= 3.08, n = 6). Using hydrological, morphometric and physical data for each lake, bottom-water [He] was predicted. A model including lake order and lake width accounted for 22% of the total variance in [He]. These results support the hypothesis that excess He in lake-bottom-water originates with deep groundwater discharge via fractures in the underlying granite.

Effect of anisotropy and groundwater system geometry on seepage through lakebeds: 1. Analog and dimensional analysis

Distribution of seepage through lakebeds is controlled partly by geometric configuration of the lake and of the groundwater system interacting with the lake. To evaluate the effect of these factors, conductive-paper electric-analog models were used to analyze a number of lake and groundwater settings having different geometric configurations. Most settings analyzed are of lakes that do not penetrate the groundwater system. The width ratio, the ratio of half the lake width to thickness of the groundwater system, is the principal geometric characteristic used in this study. Because the distribution of groundwater seepage into a lake is not uniform across the lakebed, the concept of a streamlinecrowding factor is developed, and is used to determine seepage patterns from geometric characteristics of the lake and its contiguous groundwater system. Analysis of fourteen different width ratios of lake and groundwater systems indicates that lakes can be defined by three general groups of seepage patterns, which include flow patterns, volumes and rates: (1) lakes having width ratios less than ∼ 0.6 show relatively uniform distribution of seepage across the lakebed; (2) lakes having width ratios of ∼ 0.6 to ∼ 2.0 change in absolute and relative streamline crowding in the near-shore region; and (3) lakes having width ratios greater than ∼ 2.0 show stable flow patterns near shore; however, with increasing lake width, the relative streamline crowding increases relative to that width. For deep lakes and those in anisotropic media, the crowding effect is decreased, resulting in more uniform seepage across the lakebed.

Magnetic survey of Lake Kinneret-central Jordan Valley, Israel

A magnetic survey of Lake Kinneret (Sea of Galilee) was conducted on a 1 km grid of north-south and east-west lines. The results indicate that the margins of the lake are associated with large amplitude anomalies, while the centre is quite smooth. The largest anomaly, more than 500 nT, was detected in the vicinity of the entrance of the Jordan River into the lake. Its source is interpreted to be Late Cenozoic basaltic flows. The lake's margins are associated with faults, hot springs and magnetic anomalies. A broad magnetic anomaly trending east-northeast extends from Ginosar Valley into the lake through most of the lake's width. The distribution of basalt flows of different ages and the various structures of the magnetized layers are all contributing to the magnetic anomaly pattern.