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Open pit mining frequently requires regional water tables to be lowered to access ore deposits. When mines close, dewatering ceases allowing the water table to recover. In arid and semi‐arid mining regions, the developing pit lakes are predominantly fed by groundwater during this recovery phase and pit lakes develop first into "terminal sinks" for the surrounding groundwater system. With time, the re‐establishment of regional hydraulic gradients can cause pit lakes to develop into throughflow systems, in which pit lake water outflows into adjacent aquifers. In this study, we use numerical groundwater modeling to aid process understanding of how regional hydraulic gradients, aquifer properties, net evaporation rates, and pit geometry determine the hydraulic evolution of groundwater‐fed pit lakes. We find that before the recovery of the regional water table to its new equilibrium, pit lakes frequently transition to throughflow systems. Throughflow from pit lakes to downstream aquifers can develop within two decades following cessation of dewatering even under low hydraulic gradients (e.g., 5 × 10−4) or high net evaporation rates (e.g., 2.5 m/year). Pit lakes remain terminal sinks only under suitable combinations of high evaporation rates, low hydraulic gradients, and low hydraulic conductivities. In addition, we develop an approximate analytical solution for a rapid assessment of the hydraulic status of pit lakes under steady‐state conditions. Understanding whether pit lakes remain terminal sinks or transition into throughflow systems largely determines the long‐term water quality of pit lakes and downstream aquifers. This knowledge is fundamental for mine closure and planning post‐mining land use. [ABSTRACT FROM AUTHOR]

We use digital elevation models (DEMs) and ICESat‐2 data to study the filling and outflow from a large subglacial lake under Manson Icefield in the Canadian Arctic. When full, the lake is ∼17 × 3 km with an area of 52 km2. Early in 2021 the ice surface over the center of the lake sank by >140 m implying a subglacial outburst flood of ∼4 km3. Rapid outflow occurred over ∼30 days at an average rate of ∼1,500 m3s−1 resulting in the formation of a single ∼15 km subglacial outflow path detectable from post‐outflow surface depression. The shape of the surface depression, 600–800 m wide by 2–4 m deep, reflects the shape of the subglacial channel prior to closure. Downstream ice movement appears unaffected by the outflow. After outflow ends the surface depression persisted over weeks, apparently dependent on the difference between water and overburden pressures. Plain Language Summary: Using satellite observations, we discovered a large lake under the Manson Icefield in the Canadian Arctic. Early in 2021 the ice surface over the center of the lake sank by around 140 m implying a total subglacial water outflow of around 4 km3, the largest reported outside of Iceland and Antarctica. Most of this water drained from the subglacial lake within 30 days melting some of the ice along the outflow path. For the first time we map the position and size of the subglacial output channel between the downstream end of the lake and the ocean using post‐outflow surface depression as the ice sank downward to close the channel after the water outflow. These results help in understanding the ways in which the presence, movement, and volume of water beneath glaciers influence ice movement and climate related glacial ice loss. Key Points: Using satellite height change data we document the discovery of a 52 km2 subglacial lake under the Manson Icefield, Nunavut, CanadaThe lake filled for around 14 years until early 2021 when the level in the center of the lake dropped by 130 m over 30 daysThe outflow volume was around 4 cubic kilometers and created a wide and shallow subglacial channel that could be tracked for over 15 km [ABSTRACT FROM AUTHOR]

The crucial challenge in arid/developed endorheic basins is to balance agricultural water demands with ecosystem health. This study addresses this dilemma by developing a semi-distributed socio-hydrological model for the basins using monthly water balance coupled with annual community sensitivity (CS)/response models. The central research question focuses on whether the degradation of lakes in the Tashk-Bakhtegan basin, our selected case study, can shift the community's attitude towards allocating water resources for environmental rather than agricultural purposes. Given the basin's vastness and complex water access, individuals hold diverse environmental attitudes on lake degradation. Upon model calibration, it becomes evident that downstream areas exhibit a CS variable 2.4 times higher than upstream areas, with annual fluctuations ranging from 1.15 to 6.34. Remarkably, the findings underscore a gradual transformation in downstream attitudes, where increasing CS has shifted their perspective towards prioritizing the well-being of the lake, while upstream residents continue to prioritize agro-economic benefits. [ABSTRACT FROM AUTHOR]

Influenced by climate change and human activities, plain terminal lake basins (PTLB) in arid regions experience significant shrinkage, resulting in a decline in ecosystem services (ESs) such as windbreak and sand fixation (SF) and habitat quality (HQ). However, systematic assessments of these services in such basins are limited. A key research challenge is to define and enhance the contribution of plain terminal lakes within the ESs framework of their respective basins. Therefore, this study focused on the Ebinur Lake Basin (ELB), Manas River Basin (MRB), and Tarim River Basin (TRB) in Xinjiang. We adopted both the InVEST and RWEQ models to assess ESs in these regions, by employing the production possibility frontier (PPF) to optimize various ESs, including carbon storage (CS), water yield (WY), HQ, and SF. The results indicated a general upward trend in ESs across these key basins, with a particularly significant increase in the CS. Spatial analysis revealed that regions with improved ESs were mainly concentrated in the mountainous and oasis areas of the basins, with the most pronounced improvement observed in the TRB. Within these basins, the interactions between the different ESs mainly exhibited synergistic relationships. However, notable concave trade‐off relationships existed between WY and CS, WY and HQ, and HQ and SF, particularly in the TRB. This was largely attributed to increased trade‐offs between WY and other ESs, resulting from the widespread agricultural expansion in the TRB. We plotted the optimal Pareto efficiency curves for ESs across the three basins to obtain the corresponding optimization results, and made recommendations for the enhancement of ESs. In summary, this study lays a solid scientific foundation for establishing ecological protection boundaries and promoting high‐quality sustainable development in the PTLB of arid areas. [ABSTRACT FROM AUTHOR]

Lithium is a strategic metal due to its use in green technologies, particularly battery manufacturing. It is on the US List of Critical Minerals and the European Union's List of Critical Raw Materials. In Mongolia, there are three major types of potentially economic Li deposits: (1) Deposits related to granites, granitic pegmatites and associated rocks; (2) Li-rich clay deposits; (3) Salar (Li brine) deposits. The first type of mineralization is associated with the lithium–fluorine-rich peraluminous A-type granites and related rocks (greisens, pegmatites, ongonites, ongorhyolites). The mineralization includes Li and also Sn, W, Ta and Nb. Lithium is hosted in Li-rich micas, unlike the world-class Li-bearing pegmatite deposits where the bulk of Li is in spodumene. In Mongolia, particularly promising are Li brines of endorheic basins in the Gobi Desert with an arid environment, high evaporation rates and low precipitation. [ABSTRACT FROM AUTHOR]

The natural system at Great Salt Lake, Utah, USA was augmented by the construction of a rock-filled railroad causeway in 1960, creating two lakes at one site. The north arm is sequestered from the mountain snowmelt inputs and thus became saturated with salts (250-340 g/L). The south arm is a flourishing ecosystem with moderate salinity (90-190 g/L) and a significant body of water for ten million birds on the avian flyways of the western US who engorge themselves on the large biomass of brine flies and shrimp. The sediments around the lake shores include calcium carbonate oolitic sand and clay, and further away from the saltwater margins, a zone with less saline soil. Here a small number of plants can thrive, including Salicornia and Sueda species. At the north arm at Rozel Point, halite crystals precipitate in the salt-saturated lake water, calcium sulfate precipitates to form gypsum crystals embedded in the clay, and high molecular weight asphalt seeps from the ground. It is an ecosystem with gradients and extremes, and fungi are up to the challenge. We have collected data on Great Salt Lake fungi from a variety of studies and present them here in a spatial survey. Combining knowledge of cultivation studies as well as environmental DNA work, we discuss the genera prevalent in and around this unique ecosystem. A wide diversity of taxa were found in multiple microniches of the lake, suggesting significant roles for these genera: Acremonium, Alternaria, Aspergillus, Cladosporium, Clydae, Coniochaeta, Cryptococcus, Malassezia, Nectria, Penicillium, Powellomyces, Rhizophlyctis, and Wallemia. Considering the species present and the features of Great Salt Lake as a terminal basin, we discuss of the possible roles of the fungi. These include not only nutrient cycling, toxin mediation, and predation for the ecosystem, but also roles that would enable other life to thrive in the water and on the shore. Many genera that we discovered may help other organisms in alleviating salinity stress, promoting growth, or affording protection from dehydration. The diverse taxa of Great Salt Lake fungi provide important benefits for the ecosystem. [ABSTRACT FROM AUTHOR]

Terminal lakes (without outflow) retain elements and compounds that reach them through fluvial, point source or atmospheric deposition. If the lake sediment is exposed, some of these chemicals could become toxic dust particulates. The Great Salt Lake (GSL) in Utah is a terminal lake that experienced record-low lake elevation in 2021-22, exposing vast areas of playa. Here, we used inductively coupled plasma mass spectrometry to analyze the environmental chemistry of GSL shallow sediment during historic lows in spring, summer, and fall of 2021. Contaminants at the subsurface interface are most able to influence diffusion into the water column and uptake by benthic biota. We focused our analysis on copper, thallium, arsenic, mercury, lead, and zinc, which have been historically deposited in this region and are toxic when at high concentrations. We compared records of regional mining activity to understand the current contamination and assess relevant spatial and temporal gradients. We also used two different extraction methods (EPA 3050b and NH4AcO at pH=7) that can distinguish "environmentally available" vs. tightly associated and less available fractions. We observed consistent concentration of copper across sites indicating a larger relative impact of atmospheric deposition, with some evidence indicating further impacts of point sources. Arsenic, on the other hand, is maintained at high levels in submerged sediments and is likely geologically-and fluvially- derived. Thallium and mercury fluctuate seasonally and correlate with lake elevation. Lead and zinc levels are relatively low in GSL sites compared with freshwater input sites, indicating the deep brine layer may sequester these heavy metals, preventing their release into the water column. Overall, the concentrations of most metals in GSL sediments have declined from historic highs. However, each contaminant has distinct sources, seasonality, mobility and transmission. Complete recovery (if possible) may require many more decades and individual remediation strategies. [ABSTRACT FROM AUTHOR]

We detail the effect of a small stream of dense inflow that significantly altered the stratification and water quality in a constructed water body in northern British Columbia, Canada. As the dense inflow passed through the epilimnion of the steep‐sided lake, it entrained relatively large quantities of water. The resulting mixture of dense inflow and entrained epilimnetic water sank to the bottom of the lake. The removal of water from the epilimnion due to entrainment reduced the epilimnetic thickness. This opposes the normal process of epilimnetic deepening due to wind and convective cooling. The flux of fluid entrained into the dense inflow was calculated to be between 4 and 14 times the inflow, depending primarily on the thickness of the epilimnion. The entrainment had four major effects: (1) it reduced the residence time of the epilimnion from half a year to less than a month; (2) it removed the freshwater cap that resulted from spring ice melt; (3) it enabled fall turnover, which further enhanced deep oxygen content and helped to prevent meromixis from developing in the lake; and (4) it produced a rapid decline in contaminant (i.e., zinc) concentrations in the epilimnion, which received dissolved metals inputs from oxidized sulfide minerals exposed in the subaerial walls of the lake. Given the wide variety of inflows to inland water bodies, some of which are at least seasonally dense, an understanding of the mechanisms detailed here can inform lake management in general, and more specifically, management of water quality in mine‐impacted water bodies. [ABSTRACT FROM AUTHOR]

The Great Salt Lake entered the zeitgeist of environmental concern in 2022 when a coalition of scientists and activists warned in a highly publicized report that the lake might be just five years away from complete desiccation, a possibility one state official warned was tantamount to an "environmental nuclear bomb". Shortly thereafter, an unpredicted and unprecedented pluvial winter resulted in an increase in inflow, temporarily halting the lake's decline and prompting Utah's governor to mock the dire prediction as "a joke", an outcome that speaks to the tension between agenda-setting and trust-building that researchers face when sharing worst-case warnings, particularly those based on short-term variability. Here, we describe a robust relationship between the lake and groundwater in the surrounding region and demonstrate how coupled models can thus be used to improve lake elevation predictions, suggesting that while the situation may not be as dire as some have warned, the lake remains at long-term risk as a result of climate warming. We further suggest that efforts to communicate the risk of future desiccation should be informed by stochastic variability and guided by long-term fluctuations in the total water storage of the endorheic lake's watershed. [ABSTRACT FROM AUTHOR]

If, as previously hypothesized, the effective elastic response of the lithosphere is sensitive to the imposed stress regime, then it may vary in time and produce distinctive geomorphic responses. Such effects will be at their most crucial in landscapes of low relief. Motivated by the existence of numerous small endorheic (internally‐drained) basins in central Australia, we examine the influence of changing elastic response in the presence of large embedded loads in the lithosphere underlying stable continental interiors. Focusing on the western Lake Eyre Basin and adjoining Lake Lewis basin—an area with a close correlation between drainage pattern and extreme Bouguer gravity anomalies—we devise a set of numerical simulations that incorporate the flexural response to time‐transient horizontal stresses. The simulations demonstrate that transient changes in the effective elastic thickness can drive topographic changes in low‐relief landscapes, including drainage capture and the development of endorheic basins, consistent with field observations. Plain Language Summary: Extreme density anomalies in central Australia suggest the presence of significant stress within the lithosphere, even though the region lies far from any tectonic plate boundaries. This in situ stress probably dates back to a mountain‐building period in the Paleozoic. The density anomalies correlate closely with drainage patterns and a set of internally‐drained catchments, suggesting an important relationship exists between the deep‐earth and landscape‐forming processes. We propose the driving mechanism is the result of changes in the rigidity of the lithosphere, which in the presence of in situ stress lead to surface uplift or subsidence. We use a landscape evolution model to show that topography similar to field observations can be simulated by imposing cycles of uplift and subsidence brought about by these changes in lithospheric rigidity over tens of millions of years. In consequence, the lithosphere must have fairly low rigidity counter to previously held ideas about continental interiors. Key Points: Loads embedded within the central Australian lithosphere produce large flexural responses that may evolve cyclically over timeSurface deflections induced by transient lithospheric rigidity can explain endorheic basins formed at wavelengths of order 100 kmCyclical behavior in lithospheric rigidity is consistent with the observed geomorphic record of erosion and deposition [ABSTRACT FROM AUTHOR]

The highest cycle of post‐Lake Bonneville Great Salt Lake in the Bonneville basin, Utah, USA, was thought for many years to have formed the 'Gilbert shoreline' (quotation marks indicate lack of scientific support). Mapping of the 'shoreline' is not reproducible and the concept has multiple problems, including that the 'shoreline' cannot be correlated with the well‐documented major rise of Great Salt Lake during the terminal Pleistocene. To avoid confusion, we propose abandoning the name Gilbert, which previously had been applied informally to both the hypothetical shoreline and lake cycle, and instead we use the name Currey cycle for the lake rise. During the Younger Dryas Currey cycle, Great Salt Lake became fresh to brackish about 12 700 cal a bp, and rose roughly 15 m higher than the modern lake. The end of the Currey cycle marked the beginning of extensive human occupation of the Old River Bed inland delta. [ABSTRACT FROM AUTHOR]

In the western Andes, climate changes have led to drastic ecological changes during the Pleistocene and Holocene. Given the debate surrounding precipitation pattern changes and the lack of research on lakes in the Chilean Altiplano, this study aims to assess recent climate changes. The paper presents an innovative methodology based on Google Earth Engine (GEE), utilizing fluctuations in water levels in endorheic lakes as natural precipitation indicators. Three lakes (Chungará, Miscanti, and Miniques) in isolated drainage systems were studied, where changes in water levels directly reflect rainfall variations. Data from Landsat-OLI 8, Landsat-ETM+, Landsat-TM 5, and MODIS spanning 31 years were processed using the Google Earth Engine platform. The shapes of the water bodies were extracted using hue saturation value (HSV) composites. The surface areas of the lakes were compared with precipitation data from national meteorological stations and the Tropical Rainfall Measuring Mission (TRMM) using linear regression analyses. Both lake area and rainfall volume showed a decrease over time, with varying trends depending on environmental conditions. However, the analysis consistently indicates a reduction in the area and volume of Chilean lakes corresponding to observed rainfall patterns over the past three decades. [ABSTRACT FROM AUTHOR]

Endorheic lakes, lacking river outflows, are highly sensitive to environmental changes and human interventions. Central Asia (CA) has over 6000 lakes that have experienced substantial water level variability in the past century, yet causes of recent changes in many lakes remain unexplored. Modelling hydrological processes for CA lakes poses challenges in separating climatic change impacts from human management impacts due to limited data and long-term variability in hydrological regimes. This study developed a spatially lumped empirical model to investigate the effects of climate change and human water abstraction, using Shortandy Lake in Burabay National Nature Park (BNNP) as a case study. Modelling results show a significant water volume decline from 231.7x106m3 in 1986 to 172.5x106m3 in 2016, primarily driven by anthropogenic water abstraction, accounting for 92% of the total volume deficit. The highest rates of water abstraction (greater than 25% of annual outflow) occurred from 1989 to 1993, coinciding with the driest period. Since 2013, the water volume has increased due to increased precipitation and, more importantly, reduced water abstraction. Despite limited observational data with which to calibrate the model, it performs well. Our analysis underscores the challenges in modelling lakes in data-sparse regions such as CA, and highlights the importance and benefits of developing lake water balance models for the region. [ABSTRACT FROM AUTHOR]

This study investigates the Batha endorheic basin in Chad, situated east of the Lake Chad basin in the arid to semi-arid Sahelian zone. This region has not yet undergone comprehensive geological and hydrogeological studies. More broadly, the transition zone between semi-arid and arid climates has been minimally explored. This research aims to evaluate the resources and dynamics of this multi-layered system using a combined geology-hydrogeology-hydrochemistry-isotopes approach. The multilayer system includes sedimentary layers (Quaternary, Pliocene, and Eocene) over a crystalline basement. A piezometric investigation of the system shows a general SE–NW groundwater, indicating an interconnection between all layers. Hydrochemical analyses identifies four main facies (calcium-bicarbonate, sodium-bicarbonate, sulphate-sodium, and mixed), primarily controlled by water–rock interaction with secondary influences from base-exchange and evaporation. Saturation indices indicate that these waters are close to equilibrium with the calcite-Mg phases, gaylussite and gypsum. Stable isotopes (oxygen-18 and deuterium) categorize groundwater into three groups: ancient water, recent and older meteoric water mixtures affected by evaporation, and mixtures more heavily impacted by evaporation. Tritium contents reveal three groups: current rainwater, modern water, and sub-modern water. These results indicate that ionic and isotopic differentiations cannot be strictly linked to specific layers, confirming the interconnected nature of the Batha system. The observed heterogeneity is mainly influenced by lithological and climatic variations. This study, though still limited, enhances significantly the understanding of the basin's functioning and supports the rational exploitation of its vital resources for the Batha area's development. Future investigations to complete the present study are highlighted. [ABSTRACT FROM AUTHOR]

In the face of climate change and human activities, Central Asia's (CA) terminal lake basins (TLBs) are shrinking, leading to deteriorating natural environments and serious soil wind erosion (SWE), which threatens regional socio-economic development, human health, and safety. Limited research on SWE and population exposure risk (PER) in these areas prompted this study, which applied the RWEQ and a PER model to assess the spatiotemporal changes in SWE and PER in TLBs in CA, including the Ili River Basin (IRB), Tarim River Basin (TRB), Syr Darya River Basin (SRB), and Amu Darya River Basin (ARB), from 2000 to 2020. We analyzed the driving factors of SWE and used the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model to simulate dust event trajectories. The findings from 2000 to 2020 show a spatial reduction trend in SWE and PER, with primary SWE areas in the Taklamakan Desert, Aral Sea Basin, and Lake Balkhash. Significant PER was observed along the Tarim River, near Lake Balkhash, and in the middle and lower reaches of the ARB and SRB. Over the past 21 years, temporal trends in SWE have occurred across basins, decreasing in the IRB, but increasing in the TRB, SRB, and ARB. Dust movement trajectories indicate that dust from the lower reaches of the SRB and ARB could affect Europe, while dust from the TRB could impact northern China and Japan. Correlations between SWE, NDVI, temperature, and precipitation revealed a negative correlation between precipitation and NDVI, suggesting an inhibitory impact of precipitation and vegetation cover on SWE. SWE also varied significantly under different LUCCs, with increases in cropland, forestland, and desert land, and decreases in grassland and wetland. These insights are vital for understanding SWE and PER in TLBs and offer theoretical support for emergency mitigation in arid regions. [ABSTRACT FROM AUTHOR]

Endorheic river basins and their terminal lakes are highly sensitive to climate change and human activities. Based on chemical and pollen indicators, lake level, and erosion/accumulation rates of rivers, we explore the phasing of the evolution of the river system in the Hexi Corridor during the Holocene. The results suggest that climate change dominated the evolution of the river system during the early-Mid-Holocene. Entering the historical period, humans began to have an impact on runoff, water resources, and lake evolution, and since 1000 BP, anthropogenic perturbations recorded by regional proxies increased and humans dominated the migrations of river. In addition, we discuss the widespread erosion of rivers in the global endorheic zone and the impact of human activities in this context and found the timing of human influence on river evolution is not the same in different regions. [ABSTRACT FROM AUTHOR]

This paper seeks to address the deficiency of utilizing satellite-based GRACE observations and model-based GLDAS water budget components in estimating the changes in the groundwater storage in Konya Endorheic Basin (KEB), a basin experiencing considerable land use land cover (LULC) change, primarily agricultural expansion. Cereal cultivation in the basin has a slight decreasing trend, however, the cultivation of crops with high water consumption, such as maize and sunflower, is increasing substantially. And total agricultural areas are increasing. GRACE-GLDAS approach does not accurately give the long-term groundwater decline in the basin, mainly because the land surface models employed in GLDAS cannot realistically simulate variations in water budget components as they do not consider the changes in LULC and do not possess an elaborated irrigation scheme. Here, we used a fully-distributed mesoscale hydrologic model, mHM, that can handle multiple LULC maps from different years. The model was modified to incorporate the spatio-temporal changes of agricultural fields in KEB and an explicit irrigation scheme since we hypothesized that the groundwater depletion is mainly caused by well irrigation. mHM was calibrated against streamflow observations for the period 2004–2019. The simulations show that the use of mHM with the incorporated features gives groundwater storage changes that are more consistent with the well-based observations than those obtained from the GRACE-GLDAS approach. On the other hand, the mHM simulation with a static LULC map, as in GLDAS models but with a better representation of irrigated fields, provides groundwater anomaly changes that are more consistent with the GRACE-GLDAS results, a further justification of insufficiency of the GLDAS-based approach in estimating groundwater variations for basins with considerable landscape change. [ABSTRACT FROM AUTHOR]

Digital Elevation Models (DEMs) are a crucial tool for watershed analysis, offering valuable insights into landscape‐scale hydrology. Traditional watershed delineations are derived by filling a DEM to force flow paths through topographic depressions, thus creating a continuous drainage network throughout the domain. However, this approach is challenged in landscapes with abundant real‐world depression storage, intermittently flowing stream channels, and internally drained lake basin (endorheic basin) such as the Canadian Shield (CS). The CS landscape is characterized by "fill‐and‐spill" surface water hydrology, with runoff flow paths controlled by bedrock sills and rocky cascades that overtop when water levels are high but cease flowing when water levels are low. To better represent these intermittent drainage networks, we apply a non‐traditional, less‐aggressive DEM filling model (Fill‐Spill‐Merge or FSM) to a continental‐scale DEM (MERIT) all of Canada. To ensure adequate filling of DEM noise while also preserving real‐world topographic depressions, we propose a climatic method to initialize a key FSM parameter ("runoff depth") that calibrates observed discharges from 1690 Environment and Climate Change Canada (ECCC) river gauges with climate model P‐ET (precipitation minus evapotranspiration) data. Our application of FSM to all 1690 gauged watersheds identifies 916 significant topographical control points controlling >20% and/or 1000 km2 of their respective areas. The Geikie, Snare, Kazan, Tazin, and Seal rivers may be particularly affected, with impacted watershed areas ranging from 12% to 64%. Extending this approach to ungauged parts of the CS reveals an additional 635 significant topographical control points. Ensemble climate model projections suggest that around 10% of these control points are currently dry but will become active by 2100. This research explicitly determines how CS watersheds are affected by fill‐and‐spill hydrology, and demonstrates the importance of accurate terrain modelling for delineating surface water flow paths in depressional landscapes. [ABSTRACT FROM AUTHOR]

During the early Holocene to mid-Holocene, about 11 500 to 5500 years ago, lakes expanded across the Sahel and Sahara in response to enhanced summer monsoon precipitation. To investigate the effect of these lakes on the West African summer monsoon, previous simulation studies prescribed mid-Holocene lakes from reconstructions. By prescribing mid-Holocene lakes, however, the terrestrial water balance is inconsistent with the size of the lakes. In order to close the terrestrial water cycle, we construct a dynamic endorheic lake (DEL) model and implement it into the atmosphere–land model ICON-JSBACH4. For the first time, this allows us to investigate the dynamic interaction between climate, lakes, and vegetation across northern Africa. Additionally, we investigate the effect of lake depth changes on mid-Holocene precipitation, a neglected aspect in previous simulation studies. A pre-industrial control simulation shows that the DEL model realistically simulates the lake extent across northern Africa. Only in the Ahnet and Chotts basins is the lake area slightly overestimated, which is likely related to the coarse resolution of the simulations. The mid-Holocene simulations reveal that both the lake expansion and the vegetation expansion cause a precipitation increase over northern Africa. The sum of these individual contributions to the precipitation is, however, larger than the combined effect that is generated when lake and vegetation dynamics interact. Thus, the lake–vegetation interaction causes a relative drying response across the entire Sahel. The main reason for this drying response is that the simulated vegetation expansion cools the land surface more strongly than the lake expansion, which is dominated by the expansion of Lake Chad. Accordingly, the surface temperature increases over the region of Lake Chad and causes local changes in the meridional surface-temperature gradient. These changes in the meridional surface-temperature gradient are associated with reduced inland moisture transport from the tropical Atlantic into the Sahel, which causes a drying response in the Sahel. An idealized mid-Holocene experiment shows that a similar drying response is induced when the depth of Lake Chad is decreased by about 1–5 m , without changing the horizontal lake area. By reducing the depth of Lake Chad, the heat storage capacity of the lake decreases, and the lake warms faster during the summer months. Thus, in the ICON-JSBACH4 model, the lake depth significantly influences the simulated surface temperature and the simulated meridional surface-temperature gradient between the simulated lakes and vegetation, thereby affecting mid-Holocene precipitation over northern Africa. [ABSTRACT FROM AUTHOR]

High-quality satellite precipitation products (SPPs) are needed for hydrological simulations and water resource management, especially in remote regions where rain gauges are scarce, therefore the comprehensive evaluation of SPPs is critical. In this study, an improved rank score (RS) method was used to comprehensively and quantitatively evaluate the performance of 14 SPPs at the site and basin scales on the Chinese mainland based on gauge-observed precipitation data from 2000 to 2018 in terms of continuous statistics, detection of precipitation events, and extreme metrics. The results demonstrate the following: (1) The performance of the SPPs varied significantly when evaluated using different metrics and at spatial and temporal scales. However, the Climate Prediction Center morphing technique gauge blended product (CMORPH-BLD), Multi-Source Weighted-Ensemble Precipitation (MSWEP), and Integrated Multi-Satellite Retrievals for Global Precipitation Measurement (GPM) (IMERG)-final run generally showed the best performance. (2) MSWEP performed best in the Yellow River basin (YeRB), the Tibetan Plateau's endorheic basins (TPEBs), and the Northwest endorheic basins (NWEBs), whereas CMORPH-BLD showed the best performance in the other basins of the comprehensive quantitative assessment. (3) The spatial and temporal performances of SPPs varied considerably, and the performance of SPPs was generally better in the summer (rainy season) and in the southeastern coastal basins than in the winter (dry season) and in the northwestern basins. Overall, this study provides a reference for selecting appropriate SPPs for precipitation analysis over mainland China. [ABSTRACT FROM AUTHOR]

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As climate change intensifies, understanding the dynamics of lake evaporation is imperative, especially in semi‐arid regions where water resources are already scarce. This study examines the regulatory role of lake depth on evaporation rates, focusing on a terminal lake in a semi‐arid region: Dali Lake in China. Using the Complementary Relationship Lake Evaporation model, we simulated the heat and temperature lag time of Dali Lake, an 8 m deep lake, due to its heat storage capacity. This approach was validated through moderate‐resolution imaging spectroradiometer (MODIS)‐based surface temperatures of Dali Lake and adjacent Ganggenor Lake. Dali Lake, by storing heat during the warmer months, maintains lower surface temperatures compared with the shallower Ganggenor Lake. Under the same climatic conditions, Dali Lake has an annual evaporation of 980 mm, which is 45 mm less than that of Ganggenor Lake, which has an annual evaporation of 1024 mm. To further study the impact of lake depth, we simulated the heat storage and evaporation of Dali Lake during the Holocene, when the lake reached up to 34 m average depth, representative of the maximum depth reached by Dali Lake. During the Holocene, under constant climate conditions, the annual evaporation would be 44 mm/year less than the average evaporation from 1984 to 2016. Average annual evaporation decreased with increasing depth, showing a significant reduction during warmer months, while the release of heat during the ice‐cover period did not result in additional evaporation. Our results highlight the important relationship between lake depth and evaporation under climate change, emphasizing the necessity for depth‐specific water management strategies in semi‐arid regions. [ABSTRACT FROM AUTHOR]

Measurements of oxygen and hydrogen stable isotope ratios (δ18O and δD) in meteoric waters provide insight to overlapping effects of evaporation, precipitation, and mixing on basin scale hydrology. This study of waters collected between 2016 and 2021 in the Turkana Basin, northern Kenya, uses δ18O and δD to understand water balance in Lake Turkana, a large, low‐latitude, alkaline desert lake. The Omo River, a major river system in the Ethiopian Highlands, is historically understood to provide approximately 90% of the water input to Lake Turkana. Discharge of the Omo is prohibitively difficult to measure, but stable isotope ratios in the lake may provide a meaningful method for monitoring the lake's response to changes in input. Precipitation in the Turkana Basin is low (<200 mm/year) with negligible rainfall on the lake's surface, and all water loss from the lake is evaporative. We compare new measurements with previous data from the region and records of lake height and precipitation from the same time period. We show that a Bayesian approach to modeling evaporation using atmospheric conditions and river δ18O and δD yields results consistent with published water balance models. Continued sampling of lake and meteoric waters in the Turkana Basin will be a useful way to monitor the lake's response to regional and global climate change. Plain Language Summary: Lake Turkana is the largest desert lake in the world, in one of the hottest and driest places on Earth. Studying and preserving the lake are important because people and ecosystems depend on it, but information is lacking because it is remote and irregularly monitored. Most of the water in Lake Turkana comes from the Omo River, which flows through the Ethiopian Highlands. Lake Turkana has no outlet; therefore, evaporation is the only process that removes water from the lake. In this study, we analyzed samples of lake water as well as rain, river, surface, and ground waters and developed a model that uses measurements of oxygen and hydrogen stable isotopes in the water to help us understand how much evaporation occurs in Lake Turkana. Future lake water monitoring efforts should consider stable isotope methods to record how the basin hydrology responds to climate change. Key Points: New measurements of meteoric waters from the Turkana Basin in northern Kenya plot along the meteoric water lineA lake water evaporation line is developed using Bayesian modeling applied to a terminal lake mass balance modelThe model enables predictions of lake water δ values under past and future climate change scenarios [ABSTRACT FROM AUTHOR]

This article is an editorial published in Frontiers in Environmental Science that focuses on the impact of climate change, land surface processes, and critical zone processes in endorheic basins. Endorheic basins are land-locked drainage systems that do not drain into rivers leading to the ocean. These basins are highly sensitive to climate change and human activities, but our understanding of the processes and fluxes in these areas is limited. The editorial highlights several studies that investigate the hydrological impacts of climate change, the movement of sediments, the unique hydrochemistry of these basins, and the effects of drought and vegetation changes. The authors emphasize the need for precise water resource management and climate adaptation strategies in these regions. [Extracted from the article]

Constructed from a dataset capturing the seasonal and annual water body distribution of the lower Qarqan River in the Taitma Lake area from 2017 to 2022, and combined with the meteorological and hydraulic engineering data, the spatial and temporal change patterns of the Taitma Lake watershed area were determined. Analyses were conducted using Planetscope (PS) satellite images and a deep learning model. The results revealed the following: ① Deep learning-based water body extraction provides significantly greater accuracy than the conventional water body index approach. With an impressive accuracy of up to 96.0%, UPerNet was found to provide the most effective extraction results among the three convolutional neural networks (U-Net, DeeplabV3+, and UPerNet) used for semantic segmentation; ② Between 2017 and 2022, Taitma Lake's water area experienced a rapid decrease, with the distribution of water predominantly shifting towards the east–west direction more than the north–south. The shifts between 2017 and 2020 and between 2020 and 2022 were clearly discernible, with the latter stage (2020–2022) being more significant than the former (2017–2020); ③ According to observations, Taitma Lake's changing water area has been primarily influenced by human activity over the last six years. Based on the research findings of this paper, it was observed that this study provides a valuable scientific basis for water resource allocation aiming to balance the development of water resources in the middle and upper reaches of the Tarim and Qarqan Rivers, as well as for the ecological protection of the downstream Taitma Lake. [ABSTRACT FROM AUTHOR]

Lakes are hotspots for the biogeochemical processing of carbon, including dissolved organic matter (DOM). A less degradable fraction of DOM, preserved for a long time, can be categorized as recalcitrant DOM (RDOM). Lake RDOM is an important but neglected carbon sink, and its characteristics and transformation processes remain largely unknown. Highlights: • Recalcitrant dissolved organic matter (RDOM) is an important but neglected carbon sink in lakes. • The heterogeneity of lake environments determines the diversity and complexity of RDOM. • New techniques allow detailed studies of the mechanisms of RDOM formation and related processes. [ABSTRACT FROM AUTHOR]

The response of aquatic ecosystems in the Sierra Nevada (California, USA) to late Quaternary hydroclimate changes remains mostly unknown. Mono Lake, a large endorheic lake just east of the Sierra Nevada, contains an expanded archive of laminated sediments that can be used to examine the response of benthos to environmental changes. Fossil ostracodes from a radiocarbon‐dated core were used to examine paleoecologic changes from ~16.6 to 4.3k cal a bp. Seven species were identified, with the co‐occurrence of Limnocythere ceriotuberosa and Limnocythere staplini indicating a large SO42−‐rich lake in the Pleistocene. The Younger Dryas was complex, with Fabaeformiscandona caudata reflecting a cold and deep lake ~13.0–12.2k cal a bp, followed by an interval of extensive littoral habitat from ~12.2–11.6k cal a bp. Ostracode diversity, valves g–1 and the ratio of adult:juvenile valves declined after ~10.7k cal a bp due to regression, altered hydrochemistry and seasonal anoxia. Strong seasonality during the Early Holocene is suggested by the presence of reworked ostracodes and macrocharcoal, delivered to Mono Lake by erosion of ancient lake beds in the basin. A depauperate ostracode fauna in the Middle Holocene suggests a strong sensitivity to drought in this ecosystem, which has implications for biodiversity in the future. [ABSTRACT FROM AUTHOR]

Coastal regions are vital areas globally, serving as hubs for human habitation and economic activities. Water, being the fundamental resource for life, plays a crucial role in sustaining ecosystems and shaping coastal landscapes. The convergence of river systems in coastal zones underscores their significance in the hydrological cycle and aquatic biodiversity. However, managing these valuable yet vulnerable regions presents multifaceted challenges, necessitating robust management frameworks supported by monitoring and assessment tools. In Türkiye, a country with limited freshwater resources, the management of coastal zones is particularly complex due to increasing pressure on resources and land. This study examines the distribution and characteristics of river and coastal basins in Türkiye. Through spatial analyses on Geographical Information System and basin delineations with watershed modelling program, the study clarifies the regional differences and obstacles encountered by coastal provinces spanning the entirety of Türkiye's coastal borders. The results offer valuable understanding regarding the spatial dynamics of Türkiye's coastal areas with particular emphasis on the significance of Black Sea coastal basins and all coastal provinces. Firstly, river basin systems draining into the Black Sea constitute the majority of Türkiye's surface area. Although the Black Sea region covers only 14% of the total area, more than half of the country's surface area, excluding transboundary and endorheic basins, drains into the Black Sea. Similarly, the analysis of basin types reveals that coastal basins constitute approximately 18% of the drainage areas associated with our coastal waters, nearly one-fifth. This distinction between coastal basin and river basin boundaries differs from the traditional zoning approach in river basin management and coastal area management plans in Türkiye. Consequently, it is anticipated that this spatial evaluation, which has brought a new perspective, will significantly contribute to addressing management challenges, especially the studies that will be evaluated together with population and resource use. [ABSTRACT FROM AUTHOR]

The article discusses the importance of water management and governance in shaping future outcomes. It highlights the diverse perspectives and skills that different professionals bring to the table when considering water futures, including engineers, lawyers, scientists, anthropologists, custodians, health practitioners, and artists. The article emphasizes the need for collective engagement and collaboration across these perspectives to create sustainable and just water futures. It also suggests that insights can be gained from examining the present, the past, and imagining future scenarios. [Extracted from the article]

Through 2019, the Caspian Sea excluded, the majority (54–60%) of Earth's irrigation-impacted endorheic lake and sea (ELS) areal extent has been lost in basins that contain as much as 20% of global irrigated agricultural land. Estimates of irrigated agriculture contribution to ELS desiccation based on a steady-state water balance equation for endorheic basins generally agree that this contribution is on the order of 70–90% at the global scale. However, large uncertainties or errors in attribution – as large as 100% – are observed with respect to particular ELS, suggesting that attributions based on a single irrigated agriculture dataset, should be treated cautiously. The observed areal contraction in ELS attributed to irrigated agriculture corresponds to an estimated one-third decrease in ELS volume, excluding the Caspian Sea. Such volumetric decrease is expected to at least double solute concentration in 40–47% of Earth's ELS. [ABSTRACT FROM AUTHOR]

Understanding how temporal precipitation variability will behave in the future is crucial. Change point detection and sub-trend analysis were done on monthly total precipitation data acquired from the Coordinated Regional Climate Downscaling Experiment project in this study. Sub-periods have been determined based on the natural structure of the data set, as opposed to standard sub-period determination approaches. For the period 1971–2100, six different time series were used under three global climate models (CNRM-CERFACS-CNRM-CM5, ICHEC-EC-EARTH, MPI-M-MPI-ESM-LR) and two emission scenarios (Representative Concentration Pathway (RCP) 4.5 and RCP 8.5). The study area has been selected to be the Konya Endorheic Basin in Turkey, which has been significantly influenced by climate change and human impacts. For change point detection, the Pruned Exact Linear Time method (PELT) and Binary Segmentation (BS) were employed, for trend analysis, Mann Kendall (MK) and Şen-Innovative Trend Analysis (Şen-ITA), and for both change point detection and sub-trend analysis, the Onyutha Trend Test (OTT) was utilized. The findings revealed four change points and five sub-periods. Summer precipitation has reduced considerably at a 95% significance level. There is strong evidence that precipitation has decreased between 1981 and 2070. Precipitation decreases similarly in the middle basin for the 1981–2000 and 2041–2070 years. [ABSTRACT FROM AUTHOR]

Extreme environments enable the study of simplified food-webs and serve as models for evolutionary bottlenecks and early Earth ecology. We investigated the biodiversity of invertebrate meiofauna in the benthic zone of the Great Salt Lake (GSL), Utah, USA, one of the most hypersaline lake systems in the world. The hypersaline bays within the GSL are currently thought to support only two multicellular animals: brine fly larvae and brine shrimp. Here, we report the presence, habitat, and microbial interactions of novel free-living nematodes. Nematode diversity drops dramatically along a salinity gradient from a freshwater river into the south arm of the lake. In Gilbert Bay, nematodes primarily inhabit reef-like organosedimentary structures built by bacteria called microbialites. These structures likely provide a protective barrier to UV and aridity, and bacterial associations within them may support life in hypersaline environments. Notably, sampling from Owens Lake, another terminal lake in the Great Basin that lacks microbialites, did not recover nematodes from similar salinities. Phylogenetic divergence suggests that GSL nematodes represent previously undescribed members of the family Monhysteridae—one of the dominant fauna of the abyssal zone and deep-sea hydrothermal vents. These findings update our understanding of halophile ecosystems and the habitable limit of animals. [ABSTRACT FROM AUTHOR]

The over 2200 lakes of Mongolia are generally poorly studied, particularly the glacial lakes. This overview study presents a classification of the glacial lakes based on tectonic-geological and geomorphological dynamics. Selected representative lakes are described using results from fieldwork and satellite image analysis, including bathymetry, paleoshorelines, and recent lake-level fluctuations between 1987 and 2020. Generally, lake levels dropped from the early Holocene until recently, with the onset of the climate change-driven glacier recession that has resulted in lake-level rises and area expansion in almost all moraine-dammed, tongue-basin, and ice-contact lakes. In contrast, endorheic lakes have mainly been shrinking for the past forty years because of an increase in air temperature and evaporation rates and the effects of an intensifying water use within the catchment for irrigation, mining, and hydroelectric energy production in the form of dams. The creation of a lake monitoring system based on an in-depth inventory is recommended. [ABSTRACT FROM AUTHOR]

The western region of Mongolia is characterized by an arid climate and a fragile ecological environment. It is a sensitive zone in response to global climate change and one of the major sources of dust globally. This region is home to numerous lakes, and their dynamic changes not only reflect global climate variations but also have implications for the global ecological environment quality. In this study, Landsat images were used as the data source, and Google Earth Engine (GEE) was employed to extract lakes with an area larger than 1 km2 from 1992 to 2021. The spatiotemporal characteristics of lake water area (LWA) changes were analyzed, and a structural equation model was applied to attribute the lake changes. The results indicate an overall trend of increasing lake area followed by a decrease in the study area. Specifically, lakes in the provinces of Khovd and Gobi-Altai exhibited a decreasing trend followed by an increasing trend, while lakes in the provinces of Uvs and Zavkhan showed an increasing trend followed by a decreasing trend. Three typical types of lakes, namely, alpine lakes, throughflow lakes, and terminal lakes, all exhibited a trend of increasing area followed by a decrease. The analysis of driving forces behind lake area changes reveals that climate change and human activities primarily exert indirect influences on the lake area changes in each province. Specifically, climate change and human activities lead to changes in soil moisture, which have a significant explanatory power for lake area changes. Regarding the typical types of lakes, climate change serves as the primary driving force for alpine lakes, while human activities are the main driving forces for throughflow lakes and terminal lakes. [ABSTRACT FROM AUTHOR]

Continuous and accurate precipitation data are critical to water resource management and eco-logical protection in water-scarce and ecologically fragile endorheic or inland basins. However, in typical data-scarce endorheic basins such as the endorheic basin of the Yellow River Basin (EBYRB) in China, multi-source precipitation products provide an opportunity to accurately capture the spatial distribution of precipitation, but the applicability evaluation of multi-source precipitation products under multi-time scales and multi-modes is currently lacking. In this context, our study evaluates the regional applicability of seven diverse gridded precipitation products (APHRODITE, GPCC, PERSIANN-CDR, CHIRPS, ERA5, JRA55, and MSWEP) within the EBYRB considering multiple temporal scales and two modes (annual/monthly/seasonal/daily precipitation in the mean state and monthly/daily precipitation in the extreme state). Furthermore, we explore the selection of suitable precipitation products for the needs of different hydrological application scenarios. Our research results indicate that each product has its strengths and weaknesses at different time scales and modes of coupling. GPCC excels in capturing annual, seasonal, and monthly average precipitation as well as monthly and daily extreme precipitation, essentially meeting the requirements for inter-annual or intra-annual water resource management in the EBYRB. CHIRPS and PERSIANN-CDR have higher accuracy in extreme precipitation assessment and can provide near real-time data, which can be applied as dynamic input precipitation variables in extreme precipitation warnings. APHRODITE and MSWEP exhibit superior performance in daily average precipitation that can provide data for meteorological or hydrological studies at the daily scale in the EBYRB. At the same time, our research also exposes typical problems with several precipitation products, such as MSWEP's abnormal assessment of summer precipitation in certain years and ERA5 and JRA55's overall overestimation of precipitation assessment in the study area. [ABSTRACT FROM AUTHOR]

Various isotopic and palynological indicators have shown interspersed periods of aridity and humidity for the late Paleocene to early Eocene in central China, so the paleoclimate conditions remain unclear. This research investigates the environmental characteristics of a saline lake in the Jiangling depression, southwestern Jianghan Basin, from the Paleocene to the Eocene, using bulk-rock geochemistry in a 1280 m sediment core. The ratios of FeO/MnO, Al2O3/MgO, and C-value indicate a semi-humid to semi-arid climate in the early–middle Paleocene. There was a rapid shift to a humid climate during the late Paleocene to early Eocene, following a short time of intense dryness. The Eocene climate was arid, but experienced intermittent humidity. The variation trend of the CIA, CIW and PIA was similar to that of FeO/MnO, Al2O3/MgO, and the C-value, so chemical weathering of the surrounding rocks was controlled by climate change. The lake redox conditions in the Jiangling depression from the Paleocene to the Eocene were reconstructed using the ratios of U/Th, Ni/Co, and V/Cr. During humidity and alternations of aridity and humidity, the lake water received external water input, resulting in weak stratification, so the sediments were in oxidizing conditions. During aridity, lakes become endorheic, leading to sediments forming in reduced conditions. The salinity of the lake in the Jiangling depression from the Paleocene to the Eocene was determined through analysis of sedimentary sequences and the trend of the Sr/Ba ratio. In the early–middle Paleocene, lake salinity varied greatly. From the late Paleocene to the early Eocene, lake salinity decreased. In the Eocene, lake salinity increased and halite precipitated, but lake salinity finally decreased due to a humid climate. During the late Paleocene–early Eocene, the occurrence of multiple humid climates in the Jiangling depression were not merely regional effects. The most significant humidity was caused by a global hyperthermal (PETM), which caused a huge increase in precipitation in the whole of East Asia and even in low latitudes around the world. [ABSTRACT FROM AUTHOR]

The Ecological Water Conveyance Project (EWCP) is an important measure to restore the degraded vegetation ecosystem in Qingtu Lake Wetland (QLW), a terminal lake wetland of an arid inland river basin in northwestern China. Although many previous studies have demonstrated the positive effect of EWCP for vegetation restoration, they have ignored the possible soil salinization by EWCP which could lead to re‐degradation of restored vegetation in QLW. Therefore, the purpose of this study is to reveal the potential risk of soil salinization on sustainable vegetation restoration in QLW. Three satellite remote sensing‐based indices (i.e., Normalized Difference Vegetation Index (NDVI), Salinity Index, and Normalized Difference Water Index) are used to indicate the spatio‐temporal evolutions of vegetation growth status, surface soil salinity, and water surface. Additionally, ground data of groundwater, soil, and ecological water volume are collected. The development of soil salinization and its risk on vegetation restoration as well as its controlling factors are subsequently studied by combining remote sensing and ground‐based data. The results indicate that the vegetation restored during the first few years of EWCP in the southwest, west, and north of QLW has degraded again due to the aggravation of soil salinization in these regions since 2019. Soil salinization was accelerated by the low groundwater depth with high mineralization and high evaporation capacity of climate without adequate inundation of ecological water. Under current ecological water management in QLW, soil salinization will intensify and vegetation will further degrade. The artificial management of ecological water in QLW has created a complex relationship among vegetation growth, soil salinization, and groundwater. This indicates the irrationality of using a fixed relationship between groundwater depth and NDVI for the computation of optimal ecological water volume in previous studies. More field monitoring of groundwater‐soil‐surface water‐plant‐atmosphere continuum and process‐based modeling of water‐salt transport and vegetation growth should be conducted in the future. [ABSTRACT FROM AUTHOR]

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The McMurdo Dry Valleys (MDV) are home to a unique microbial ecosystem that is dependent on the availability of freshwater. This is a polar desert and freshwater originates almost entirely from surface and near-surface melt of the cold-based glaciers. Understanding the future evolution of these environments requires the simulation of the full chain of physical processes from net radiative forcing, surface energy balance, melt, runoff and transport of meltwater in stream channels from the glaciers to the terminal lakes where the microbial community resides. To establish a new framework to do this, we present the first application of WRF-Hydro/Glacier in the MDV, which as a fully distributed hydrological model has the capability to resolve the streams from the glaciers to the bare land that surround them. Given that meltwater generation in the MDV is almost entirely dependent on small changes in the energy balance of the glaciers, the aim of this study is to optimize the multi-layer snowpack scheme that is embedded in WRF-Hydro/Glacier to ensure that the feedbacks between albedo, snowfall and melt are fully resolved. To achieve this, WRF-Hydro/Glacier is implemented at a point scale using automatic weather station data on Commonwealth Glacier to physically model the onset, duration and end of melt over a 7-month period (1 August 2021 to 28 February 2022). To resolve the limited energetics controlling melt, it was necessary to (1) limit the percolation of meltwater through the ice layers in the multi-layer snowpack scheme and (2) optimize the parameters controlling the albedo of both snow and ice over the melt season based on observed spectral signatures of albedo. These modifications enabled the variability of broadband albedo over the melt season to be accurately simulated and ensured that modelled surface and near-surface temperatures, surface height change and runoff were fully resolved. By establishing a new framework that couples a detailed snowpack model to a fully distributed hydrological model, this work provides a stepping stone to model the spatial and temporal variability of melt and streamflow in the future, which will enable some of the unknown questions about the hydrological connectivity of the MDV to be answered. [ABSTRACT FROM AUTHOR]

The Salton Sea is the largest lake in California and is a shallow, hypersaline lake. The endorheic lake has been significantly maintained by agricultural return flows from Imperial Valley farming and two rivers- the New River and Alamo River- which originate in Mexicali, Mexico. The current salinity is at 74 ppt and is expected to increase due to the Quantification Settlement Agreement signed in 2003, stipulating the transfer of nearly 0.616 km³ per year of Colorado River water to urban areas for up to 75 years. This has resulted in inflows reduction, and the dust storms created by the dried-up playa have become a prominent risk to public health in the region. Massive fish and bird kills began in the 1980s and continued to occur periodically. In this study, the Delft3D numerical modeling suite- FLOW, WAVE, and WAQ- was utilized to investigate the transport and cycling of nutrients under the influence of wind-induced sediment resuspension activity. The three-dimensional hydrodynamic and water quality combined model was applied to simulate mitigation scenarios to assess long-term effects on salinity and water quality of (1) emerged islands as a nature-based solution, (2) seawater import/export, and (3) seawater import/export in addition to treating tributary rivers to remove nutrients. Overall, this study supported the findings fromprevious studies and showed that sediment resuspension is the driving force for nutrients cycling in the water column and that emerged islands have long-term potential to enhance burial activity for pollutants removal in the Salton Sea. Furthermore, the seawater import/export scenario showed promising results of reducing salinity level from 46 ppt to 38-39 ppt in 2 years. The 3D numerical hydrodynamic/water quality model developed in this work is the first and latest integrated modeling approach tailored to the Salton Sea's system and has the capacity to improve understanding of the complicated water quality dynamics changes in various restoration concepts. This study demonstrated that being able to explore the full potentials of restoration designs using a comprehensive 3D water quality modeling framework is critical in achieving wholesome planning that will create environmental, social, and economic benefits in the long term for the Salton Sea. [ABSTRACT FROM AUTHOR]

During the early to mid-Holocene, about 11,500 to 5,500 years ago, lakes expanded across the Sahel and Sahara in response to enhanced summer monsoon precipitation. To investigate the effect of these lakes on the West African summer monsoon, previous simulation studies prescribed mid-Holocene lakes from reconstructions. By prescribing mid-Holocene lakes, however, the terrestrial water balance is inconsistent with the size of the lakes. In order to close the terrestrial water cycle, we construct a dynamic endorheic lake (DEL) model and implement it into the atmosphere-land model ICON-JSBACH4. For the first time, this allows us to investigate the dynamic interaction between climate, lakes and vegetation over northern Africa. Additionally, we investigate the effect of lake depth changes on the mid-Holocene precipitation, which was neglected in previous simulation studies. A pre-industrial control simulation shows that the DEL model realistically simulates the lake extent over northern Africa. Only in the Ahnet and Chotts Basin is the lake area slightly overestimated, which likely relates to the coarse resolution of the simulations. The mid-Holocene simulations reveal that both, the lake expansion and the vegetation expansion cause a precipitation increase over northern Africa. The sum of these individual contributions on the precipitation is however larger than the combined effect, when lake and vegetation dynamics interact. Thus, the lake-vegetation interaction causes a relative drying response over the entire Sahel. The main reason for this drying response is that the simulated vegetation expansion cools the land surface more strongly than the lake expansion, mainly the expansion of the Lake Chad area. The resulting warming response over the larger lake area causes local changes in meridional surface-temperature gradient that decelerate the inland moisture transport from the tropical Atlantic into the Sahel, which causes a drying response in the Sahel. An idealized mid-Holocene experiment shows that a similar drying response is induced when the depth of Lake Chad is decreased by about 1–5 m, without changing the horizontal lake area. By reducing the depth of Lake Chad the heat storage capacity of the lake decreases and the lakes warms faster during the summer months. Thus, in the ICON-JSBACH4 model, the lake depth significantly influences the simulated surface temperature and the simulated meridonal surface-temperature gradient between the simulated lakes and vegetation and thus, the mid-Holocene precipitation over northern Africa. [ABSTRACT FROM AUTHOR]

Atmospheric photochemistry on Titan continuously transforms methane and nitrogen gases into various organic compounds. This study explores the fate of these molecules when they land on Titan's surface. Our analytical exploration reveals that most simple organics found in Titan's atmosphere, including all nitriles, triple‐bonded hydrocarbons, and benzene, land as solids. Only a few compounds are in the liquid phase, while only ethylene remains gaseous. For the simple organics that land as solids, we further examine their interactions with Titan's lake liquids. Utilizing principles of buoyancy, we found that flotation can be achieved via porosity‐induced (25%–60% porosity) or capillary force‐induced buoyancy for hydrogen cyanide ices on ethane‐rich lakes. Otherwise, these ices would sink and become lakebed sediments. By evaluating the timescale of flotation, our findings suggest that porosity‐induced flotation of millimeter‐sized and larger sediments is the only plausible mechanism for floating solids to explain the transient "magic islands" phenomena on Titan's lakes. Plain Language Summary: Titan, Saturn's largest moon, has a unique atmosphere that transforms simple gases like methane and nitrogen into more complex organic compounds. In this study, we explored what happens to these organic compounds when they reach Titan's surface. We find that most molecules would land as solids. We also looked at what happens when these solids land on Titan's hydrocarbon lakes. Imagine a sponge, full of holes; if the solids are like this, with 25%–60% of their volume being empty space, they can float. Some solids, like hydrogen cyanide ice, can also float due to surface tension effects. If these conditions are not met, they sink into the lake liquids, adding to the lakebed sediments. We examine whether floating rafts can explain a mysterious feature on Titan's lakes known as the "magic islands." These are temporary bright spots seen by radar. By looking at how long the materials will float for each scenario, our study suggests that the magic islands might be made of large chunks of porous organic solids. Key Points: Most simple organics land as solids on Titan's surface, including all nitriles, triple‐bonded hydrocarbons, and benzeneOrganics may float on Titan's lakes via porosity or capillary force‐induced flotation, the latter is unique to hydrogen cyanide ice on ethane‐rich lakesPorosity‐induced flotation of millimeter‐sized and larger particles may explain the transient radar‐bright magic islands on Titan's lakes [ABSTRACT FROM AUTHOR]

The MERIT-Hydro networks re-gridded by the Iterative Hydrography Upscaling (IHU) algorithm do not retain exo- or endorheic basin attributes from the original data. Here we developed methods to assign such attributes to those and any other digital river networks. The motivation is that endorheic inland drainage basins are essential for hydrologic modelling of global and regional water balances, land surface water storage, gravity anomalies, sea level rise, etc. First, we create basin attributes that explicitly label endorheic and exorheic catchments by the criteria of direct or hidden connectivity to the ocean without changing their flow direction grid. In the second step we alter the delineation of endorheic basins by the merging algorithm that eliminates small inland watersheds to the adjacent host basins. The resulting datasets have a significantly reduced number of endorheic basins while preserving the total land portion and topology of the inland basins. The data was validated using the Water Balance Model by comparing volume of endorheic inland depressions with modelled water accumulation in their inland lakes. [ABSTRACT FROM AUTHOR]

In the context of climate change, precipitation and runoff in the arid inland basins of northwest China have undergone significant changes. The Qaidam Basin (QB) is a typical highland arid inland area. Understanding the spatial and temporal variations in surface water and groundwater chemistry and isotopes, as well as their causes, is crucial for future water resource management and ecological protection. Samples of river, lake, and groundwater, as well as others, were collected and tested in five typical watersheds in the summer and winter. The hydrochemistry and isotopic spatiotemporal differences in various water bodies were studied using the significant difference method, water vapor flux models, hydrochemistry, isotopes, and other methods for cause analyses. The results indicate the following: (1) There are differences in hydrochemistry between the southern and northern basins because the southern basin is more influenced by the dissolution of salt rocks and evaporation, whereas the northern basin is mainly affected by carbonate weathering. (2) The enrichment of δD and δ18O in the northern basin gradually increases from west to east, while in the southern basin, it is the opposite. This is because the southern basin receives a larger contribution of water vapor from the mid-latitude westerlies, while the northern basin primarily relies on local evaporation as its water vapor source. (3) Significant differences are observed in the total dissolved solids (TDS) and hydrochemical types of river water and groundwater between the summer and winter due to higher rates of rock weathering and evaporation in the summer. (4) The more pronounced seasonal differences in hydrogen and oxygen stable isotopes in the southern basin are due to higher rates of internal water vapor circulation in the summer. (5) The similarity in characteristics between river water and groundwater is the result of strong exchanges between river water and groundwater from piedmonts to terminals. The spatiotemporal heterogeneity of terminal lakes is attributed to the accumulation of salts and groundwater replenishment from other sources. [ABSTRACT FROM AUTHOR]

The endorheic Konya Basin is a vast aggradational plain in Central Anatolia, Türkiye. It occupies a significant portion of Konya Province, covering approximately 50,000 km2. The basin is subjected to intense groundwater withdrawal and extensive agricultural activities with excessive irrigation. These activities have led to human-induced hazards, such as sinkholes and regional land subsidence. Although sinkhole occurrence mainly occurs in the Karapınar area, land subsidence is primarily observed in the central sector of Konya city, with 2 million inhabitants, as well as in various parts of the basin. This study focuses on determining the extent and rate of land subsidence throughout the basin, understanding sinkhole formation, and unraveling their relationship with anthropogenic activities. For this purpose, Interferometric Synthetic Aperture Radar (InSAR) analysis of Sentinel-1 data from 2014 to 2022 was conducted to identify and assess land subsidence. We also used the land cover data and groundwater-level information to better understand the spatial and temporal patterns of land subsidence and sinkhole occurrence. Additionally, the land cover data were used to resolve spatial–temporal variations in the cultivated area and urbanization, which are the main factors governing groundwater exploitation in the region. Our study identified widespread subsidence zones with rates as high as 90 mm/y. Groundwater overexploitation to sustain extensive agricultural operations is the main cause of the high rate of land subsidence. Additionally, it was discovered that the number of sinkholes has substantially increased due to anthropogenic influences, currently amounting to as many as 660. [ABSTRACT FROM AUTHOR]

A few studies on ozone deposition over lake water are available and so far only one using the eddy covariance technique (Wesely et al., 1981, https://doi.org/10.1007/BF00122295). A 23‐day field campaign was held in August‐September 2012 at the Lake Kuivajärvi in Hyytiälä, Finland. The results showed a mean flux of −30 ± 1 ng m−2 s−1 and deposition velocity of 0.86 ± 0.05 mm s−1. Deposition velocity showed a weak diurnal cycle over the lake with elevated values during the nighttime. The daytime and nighttime portions of the data set differed statistically. Analysis showed that waterside convective mixing enhanced deposition and such conditions pre‐dominantly occurred during nighttime. We compared the measured deposition velocities with the dry deposition model of air‐sea exchange, adjusted for the chemical sinks relevant for the lake. We suggest that the buoyant mixing and unaccounted chemistry can be responsible for the difference between the model results and observations. Plain Language Summary: Ozone deposition was studied over lake in Southern Finland. Deposition velocity showed elevated values during the nighttime. Higher ozone deposition at night was related to enhanced convective mixing in uppermost water layers. Key Points: Ozone deposition over the lake is enhanced by waterside buoyancy velocityWind speed and friction velocity had minor or no impact on ozone deposition, instead waterside convective mixing enhanced depositionIn late summer, over diurnal course higher deposition velocities occurred at night [ABSTRACT FROM AUTHOR]

Lake Shala, endorheic Soda Lake in the Ethiopian Riftvally Lake, supports an enormous biodiversity, with a large human population and economic development. However soda lakes are under several ecological changes, with unexpected shifts in biodiversity composition and physicochemical changes. This study focuses on assessing the community structure of zooplankton in Lake Shala. Samples were taken at monthly intervals from January to December 2018. A total of 32 zooplankton species were identified, of which 23 species were Rotifers and followed by Copepoda (6) and Cladocera (3). The community was dominated by Brachionus dimidiatus, B. dimidiatus inermis, B. plicatilis and B. calyciflorus. Their abundance exhibit significant seasonal and vertical variations (ANOVA, p < 0.05). Zooplankton community structure of Lake Shala has changed over time, benthic harpacticoids (Nitocra lacustris) have become replaced by small-bodied and generalist-feeder rotifers (genus Brachionus). Such ecological shifts may be driven mainly by partial atelomixis in this deep tropical lake. Overall, zooplankton species distribution and abundance are influenced by various environmental factors such as conductivity, salinity, Chl-a and nutrients. This study concludes that the composition and community structure of zooplankton in Lake Shala has changed over time with the change in physicochemical and internal limnological dynamics (atelomix). [ABSTRACT FROM AUTHOR]