Inventory and classification of the post Little Ice Age glacial lakes in Svalbard

Rapid changes of glacial lakes are among the most visible indicators of global warming in glacierized areas around the world. The general trend is that the area and number of glacial lakes increase significantly in high mountain areas and polar latitudes. However, there is a lack of knowledge about the current state of glacial lakes in the High Arctic. This study aims to address this issue by providing the first glacial lake inventory from Svalbard, with focus on the genesis and evolution of glacial lakes since the end of the Little Ice Age. We use aerial photographs and topographic data from 1936 to 2012 and satellite imagery from 2013 to 2020. The inventory includes the development of 566 glacial lakes (total area of 145.91 km2) that were in direct contact with glaciers in 2008–2012. From the 1990s to the end of the 2000s, the total glacial lake area increased by nearly a factor of six. A decrease in the number of lakes between 2012 and 2020 is related to two main processes: the drainage of 197 lakes and the merger of smaller reservoirs into larger ones. The changes of glacial lakes show how climate change in the High Arctic affect proglacial geomorphology by enhanced formation of glacial lakes, leading to higher risks associated with glacier lake outburst floods in Svalbard.

Hydrochemical Approach to Groundwater in the Environment of the Public Discharge of Lake Mbeubeuss (Dakar, Senegal)

To determine the origin and the processes of groundwater mineralization in the Mbeubeuss lake area, the major ion concentrations of the groundwater were compared to those of the rainwaters which constitute the input function of the aquifer of the Quaternary sands in the area of lake Mbeubeuss. The physico-chemistry of groundwater near the public discharge and its surroundings, has shown that the true value of the electrical conductivity of waters are around 2000 µS/cm. Values of electrical conductivity greater than 2000 µS/cm would represent the particular mineralization of ground waters by the public discharge of lake Mbeubeuss. The chemical facies of ground waters are dominated by the sodium and potassium chloride and calcium chloride facies. The study of the relationship between the major chemical elements and the chloride ion and the representation in the modified Chadha diagram of the chemical analyzes of ground waters from the campaigns of July 1998, July 2002 and March 2003, made it possible to highlight the different sources and processes controlling the mineralization of ground waters in the Mbeubeuss Lake area. Despite the proximity to the sea which suggests a considerable contribution of salts by aerosols and sea spray, the mineralization of ground waters in the area of lake Mbeubeuss is largely due to leachate from household waste and the influence of old sediments of the dry lake Mbeubeuss. The main processes controlling the mineralization of ground waters are marine contributions (aerosols and sea spray), dissolution-precipitation of minerals from the aquifer matrix, atmospheric CO2 diffusion, base exchanges, dilution-concentration and anthropogenic pollution.

CAEC (COMMUNITY OF ACTIVE ENGLISH COMMUNICATION)-BASED EMPOWERMENT OF LAKE TEMPE WAJO TOURISM REGIONAL COMMUNITIES

South Sulawesi's Lake Tempe is a popular tourist site. Many foreigners, both locally and internationally, visit Lake Tempe. The quality of the guide's service has a significant impact on the smoothness and comfort of travel in Tempe. As a result, a training and mentoring program for foreign-language tourism performers in the Tempe Lake area is required. The PKM program is carried out in stages: (1) PKM participant selection; (2) PKM briefing participants; (3) survey site; (4) PKM program socialization; (5) debriefing tourist actors; and (6) twice-weekly training and mentorship for three months. In total, 25 meetings were held to provide training and mentorship. The training team enhances the vocabulary at the start of the training, and subsequently, the material and speaking are intensified by the team. The assessment's findings revealed a significant increase: (1) There were three people in the very good group, 25 in the good category, and two in the bad category when it came to vocabulary ability. (2) There are 26 persons who are classified as good at tenses, and just four people who are classified as less good. (3) In terms of speaking skill, four people were rated as very good, 25 were rated as good, and one was rated as less good.

Distribution of Heterotrophic and Nitrogen fixing Rhizobacteria in Irrigation Sites of Lake Alau Borno State Northeastern Nigeria

This study was conducted to know the population of rhizobacteria in both irrigation and non-irrigation sites of the dam. The dense population of these organism indirectly promote plant growth and development. Five sites (A, B, C, D and E) were used to collect soil samples randomly and transported to the laboratory for analysis. Total heterotrophic bacterial count was done using nutrient agar (NA) and nitrogen fixing bacteria was counted using Ashbey’s media (AM). The result shows that highest number of total heterotrophic bacteria in site C (46.0×106) cfu/g in irrigation site whereas higher count in non-irrigation site was (13.0×106) site D, the nitrogen fixing bacterial count in irrigation site was higher at site E with (12.0×106) and for the non-irrigation site was higher at site D with (14.0×106) The total heterotrophic bacteria isolated in the soil sample are the species of Bacillus alvei, Bacillus alvei, Bacillus cereus, Bacillus cereus, Pseudomonas putida, Klebsiella aeruginosa and Enterobacter aeruginosa. Likewise, the Nitrogen fixing bacteria isolated are the species of Rhizobium leguminosarum, Klebsiella pneumonia, Bacillus lentus, Azotobacter nigricans, Azotobacter tropicalis, Azotobacter spp, and Azotobacter tropicalis. The long history of agricultural activities in the lake area has directly influenced the diversity of microbial population in the area.

Hydrological Conditions Of Drained Lake Basins Of The Anadyr Lowland Under Changing Climatic Conditions

The lakes of the Arctic lowlands are both the unique indicator and the result of climatic and permafrost changes. Remote sensing methods and field measurements were used to consider the patterns and features of the morphometric indicators dynamics of the Anadyr lowland lakes over 65 years. We analyzed the parameters of 36 lakes with an area of 0.02–0.3 km2 located in the bottoms of drained lake basins, in river floodplains, on sea-shore terraces. Field studies were conducted on 22 typical lakes. The considered dynamics of seasonal thawing are based on the monitoring of the active layer for 1994–2020. Due to an increase of mean annual air temperature by 1.8 °C, as well as an increase and then a decrease in the mean annual precipitation by 135 mm, the average share of a lake area in the study area decreased by 24%. It is shown for the first time that cryogenic processes of the lacustrine coastal zone affect the change in the area of lakes simultaneously with the influence of precipitation and air temperature. Based on field observations, we considered two causes of natural drainage: discharge of the lakes through newly formed thermokarst and thermoerosional surface flow channels and decrease in suprapermafrost groundwater recharge as a result of changing depth of seasonally thawed active layer in the coastal zone.

Seasonal Evolution of Supraglacial Lakes on Baltoro Glacier From 2016 to 2020

The existence of supraglacial lakes influences debris-covered glaciers in two ways. The absorption of solar radiation in the water leads to a higher ice ablation, and water draining through the glacier to its bed leads to a higher velocity. Rising air temperatures and changes in precipitation patterns provoke an increase in the supraglacial lakes in number and total area. However, the seasonal evolution of supraglacial lakes and thus their potential for influencing mass balance and ice dynamics have not yet been sufficiently analyzed. We present a summertime series of supraglacial lake evolution on Baltoro Glacier in the Karakoram from 2016 to 2020. The dense time series is enabled by a multi-sensor and multi-temporal approach based on optical (Sentinel-2 and PlanetScope) and Synthetic Aperture Radar (SAR; Sentinel-1 and TerraSAR-X) remote sensing data. The mapping of the seasonal lake evolution uses a semi-automatic approach, which includes a random forest classifier applied separately to each sensor. A combination of linear regression and the Hausdorff distance is used to harmonize between SAR- and optical-derived lake areas, producing consistent and internally robust time series dynamics. Seasonal variations in the lake area are linked with the Standardized Precipitation Index (SPI) and Standardized Temperature Index (STI) based on air temperature and precipitation data derived from the climate reanalysis dataset ERA5-Land. The largest aggregated lake area was found in 2018 with 5.783 km2, followed by 2019 with 4.703 km2, and 2020 with 4.606 km2. The years 2016 and 2017 showed the smallest areas with 3.606 and 3.653 km2, respectively. Our data suggest that warmer spring seasons (April–May) with higher precipitation rates lead to increased formation of supraglacial lakes. The time series decomposition shows a linear increase in the lake area of 11.12 ± 9.57% per year. Although the five-year observation period is too short to derive a significant trend, the tendency for a possible increase in the supraglacial lake area is in line with the pronounced positive anomalies of the SPI and STI during the observation period.

COVID-19 and Tourism in Pokhara: Strategies for Industry’s Recovery

Tourism is considered as travel related activities. Pokhara has many attractions for tourists including lakes, hills, religious and cultural sites. The presence of Phewa Lake in the west, Begnas Lake in the east attracts a large number of domestic and international tourists. The main objective of this study is to explore the impact of COVID-19 on tourism of Pokhara. Altogether 120 samples were taken purposively in the major touristic areas of Pokhara. Interviews were taken with key informants and the observation technique was also used. The obtained data were discussed in the form of table, charts and figures. The number of tourists visiting Pokhara is found decreasing over the last two years due to the Covid-19 pandemic. High quality hotels are only in the Phewa Lake area whereas there are very few quality hotels in the study area, so quality hotels with better facilities should be established in other areas, too. New tourism activities need to be explored and after the operation of international airport, the option for the present paragliding spots need to be managed in time. To minimize the impact of Covid-19 pandemic, there should be a provision of easy refinancing facilities from the financial institutions to be provided to the tourism entrepreneurs, including subsidies on the equated monthly instalments and decreasing the interest rate and quick vaccination to the people involved in tourism sectors.

Automated mapping of the seasonal evolution of surface meltwater and its links to climate on the Amery Ice Shelf, Antarctica

Surface meltwater is widespread around the Antarctic Ice Sheet margin and has the potential to influence ice shelf stability, ice flow and ice–albedo feedbacks. Our understanding of the seasonal and multi-year evolution of Antarctic surface meltwater is limited. Attempts to generate robust meltwater cover time series have largely been constrained by computational expense or limited ice surface visibility associated with mapping from optical satellite imagery. Here, we add a novel method for calculating visibility metrics to an existing meltwater detection method within Google Earth Engine. This enables us to quantify uncertainty induced by cloud cover and variable image data coverage, allowing time series of surface meltwater area to be automatically generated over large spatial and temporal scales. We demonstrate our method on the Amery Ice Shelf region of East Antarctica, analysing 4164 Landsat 7 and 8 optical images between 2005 and 2020. Results show high interannual variability in surface meltwater cover, with mapped cumulative lake area totals ranging from 384 to 3898 km2 per melt season. By incorporating image visibility assessments, however, we estimate that cumulative total lake areas are on average 42 % higher than minimum mapped values. We show that modelled melt predictions from a regional climate model provide a good indication of lake cover in the Amery region and that annual lake coverage is typically highest in years with a negative austral summer SAM index. Our results demonstrate that our method could be scaled up to generate a multi-year time series record of surface water extent from optical imagery at a continent-wide scale.

Analysis of Factors Influencing the Lake Area on the Tibetan Plateau Using an Eigenvector Spatial Filtering Based Spatially Varying Coefficient Model

Lakes on the Tibet Plateau (TP) have a significant impact on the water cycle and water balance, and it is important to monitor changes in lake area and identify the influencing factors. Existing research has failed to quantitatively identify the changes and influencing factors of lakes in different regions of the TP. Thus, an eigenvector spatial filtering based spatially varying coefficient (ESF-SVC) model was used to analyze the relationship between lake area and climatic and terrain factors in the inner watershed of the TP from 2000 to 2015. A comparison with ordinary regression and spatial models showed that the ESF-SVC model eliminates spatial autocorrelation and has the best model fit and complexity. The experiments demonstrated that precipitation, snow melt, and permafrost moisture release, as well as the area of vegetation and elevation difference in the watershed, can significantly promote the expansion of lakes, while evapotranspiration and days of mean daily temperature above zero have an inhibitory effect on lake area expansion. The degree of influence of each factor also differs significantly over time and across regions. Spatially quantitative modeling of lake area in the TP using the ESF-SVC method is a new attempt to provide novel ideas for lake research.

Long-Term Lake Area Change and Its Relationship with Climate in the Endorheic Basins of the Tibetan Plateau

Lakes are sensitive indicators of climate change in the Tibetan Plateau (TP), which have shown high temporal and spatial variability in recent decades. The driving forces for the change are still not entirely clear. This study examined the area change of the lakes greater than 1 km2 in the endorheic basins of the Tibetan Plateau (EBTP) using Landsat images from 1990 to 2019, and analysed the relationships between lake area and local and large-scale climate variables at different geographic scales. The results show that lake area in the EBTP has increased significantly from 1990 to 2019 at a rate of 432.52 km2·year−1. In the past 30 years, lake area changes in the EBTP have mainly been affected by local climate variables such as precipitation and temperature. At a large scale, Indian Summer Monsoon (ISM) has correlations with lake area in western sub-regions in the Inner Basin (IB). While Atlantic Multidecadal Oscillation (AMO) has a significant connection with lake area, the North Atlantic Oscillation (NAO) does not. We also found that abnormal drought (rainfall) brought by the El Niño/La Niña events are significantly correlated with the lake area change in most sub-regions in the IB.