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\"The Earth's oceans are on the rise. Since 1900, global sea levels have risen steadily each year to a global average of about 8 inches (20cm) today, and they're still rising. By 2100, the sea could climb as much as 14 feet (4.3m) to 32 feet (9.75m). Rising Seas: Flooding, Climate Change and Our New World gives youth an eye-popping view of what the Earth might look like under the rising and falling water levels of climate change. Photographs juxtapose the present-day with that same area's projected future. The shocking images will help them understand the urgency for action. Key issues in today's news will be better understood, such as the 2015 Paris Protocol in which the world agreed to limit temperature increases to 2 degrees Celsius (ideally 1.5 degree). This new edition features three new locations, updated information and new features about climate anxiety and reasons to hope for change.\"-- Provided by publisher

Coastal areas epitomize the notion of ‘at-risk’ territory in the context of climate change and sea level rise (SLR). Knowledge of the water level changes at the coast resulting from the mean sea level variability, tide, atmospheric surge and wave setup is critical for coastal flooding assessment. This study investigates how coastal water level can be altered by interactions between SLR, tides, storm surges, waves and flooding. The main mechanisms of interaction are identified, mainly by analyzing the shallow water equations. Based on a literature review, the orders of magnitude of these interactions are estimated in different environments. The investigated interactions exhibit a strong spatiotemporal variability. Depending on the type of environments (e.g., morphology, hydrometeorological context), they can reach several tens of centimeters (positive or negative). As a consequence, probabilistic projections of future coastal water levels and flooding should identify whether interaction processes are of leading order, and, where appropriate, projections should account for these interactions through modeling or statistical methods.

Being one of the most vulnerable regions in the world, the Ganges–Brahmaputra–Meghna delta presents a major challenge for climate change adaptation of nearly 200 million inhabitants. It is often considered as a delta mostly exposed to sea-level rise and exacerbated by land subsidence, even if the local vertical land movement rates remain uncertain. Here, we reconstruct the water-level (WL) changes over 1968 to 2012, using an unprecedented set of 101 water-level gauges across the delta. Over the last 45 y, WL in the delta increased slightly faster (∼3 mm/y), than global mean sea level (∼2 mm/y). However, from 2005 onward, we observe an acceleration in the WL rise in the west of the delta. The interannual WL fluctuations are strongly modulated by El Niño Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD) variability, with WL lower than average by 30 to 60 cm during co-occurrent El Niño and positive IOD events and higher-than-average WL, by 16 to 35 cm, during La Niña years. Using satellite altimetry and WL reconstructions, we estimate that the maximum expected rates of delta subsidence during 1993 to 2012 range from 1 to 7 mm/y. By 2100, even under a greenhouse gas emission mitigation scenario (Representative Concentration Pathway [RCP] 4.5), the subsidence could double the projected sea-level rise, making it reach 85 to 140 cm across the delta. This study provides a robust regional estimate of contemporary relative WL changes in the delta induced by continental freshwater dynamics, vertical land motion, and sea-level rise, giving a basis for developing climate mitigation strategies.

Water level change upstream of a reservoir highlights the risk of a landslide-prone area on the banks of a reservoir. This paper conducted a study on the deformation mechanism of a selected landslide that occurred in the Three Gorges Reservoir (TGR) after the water level of the reservoir changed. The long-monitored surface deformation of the slide mass revealed that the deformation of the landslide was related to the water level changes in the reservoir, especially of the change between flood and floodless seasons. The measured internal lateral displacements in the landslide showed that such a landslide was characterized by a trail-mode. FLAC3D was adopted to model the landslide by examining the plastic zone, factor of safety, and the displacement in the x-direction in consideration of four conditions: the natural state of a landslide in the TGR, the initial impoundment, the subsequent rise of water level, and the drawdown of water level. The numerical results indicated that the landslide mass tended to be unstable during the initial impoundment; the subsequent rise of water level had a limited effect on the landslide happening, but the drawdown of water level directly triggered the landslide. The landslide changed from push-mode to trail-mode. It is strongly recommended that drawdown of the water level in the reservoir be carefully controlled to mitigate the effect on landslide mass.

Accurate and detailed information on lake/reservoir water levels and temporal changes around the globe is urgently required for water resource management and related studies. The traditional satellite radar altimeters normally monitor water level changes of large lakes and reservoirs (i.e., greater than 1 km2) around the world. Fortunately, the recent Ice, Cloud, and land Elevation Satellite-2 (ICESat-2) makes it possible to monitor water level changes for some small lakes and reservoirs (i.e., less than 1 km2). ICESat-2 ATL13 products provide observations of inland water surface heights, which are suitable for water level estimation at a global scale. In this study, ICESat-2 ATL13 products were used to conduct a global estimation and assessment of lake/reservoir water level changes. We produced monthly water levels for 13,843 lakes and reservoirs with areas greater than 0.1 km2 and all-season ATL13 products across the globe, in which 2257 targets are smaller than 1 km2. In total, the average valid number of months covered by ICESat-2 is 5.41 months and only 204 of 13,843 lakes and reservoirs have water levels in all the months in 2019. In situ water level data from 21 gauge stations across the United States and 12 gauge stations across Australia were collected to assess the monthly lake/reservoir water levels, which exhibited a high accuracy (RMSE = 0.08 m, r = 0.999). According to comparisons between the monthly water levels and changes from ATL08 products in another study and ATL13 products in this study, we found that both products can accurately estimate the monthly water level of lakes and reservoirs, but water levels derived from ATL13 products exhibited a higher accuracy compared with water levels derived from ATL08 products (RMSE = 0.28 m, r = 0.999). In general, the ATL13 product is more convenient because the HydroLAKES mask of inland water bodies, the orthometric height (with respect to the EGM2008 geoid) of water surfaces, and several data quality parameters specific to water surfaces were involved in the ATL13 product.

The upper few hundreds of meters of the crust often hosts leaky aquifers. Quantifying leakage is important if those aquifers are used as a water resource. The responses of water level to external forcing such as tides and barometric pressure changes offer the opportunity to measure aquifer hydrogeological properties and monitor possible changes in those properties. Around the Huayingshan faults adjacent to Sichuan and Chongqing provinces, China, inclined fold‐and‐thrust belts form the crust, and frequent earthquakes might impact aquifers in the shallow crust that are used for drinking water. We introduce a new computational approach for continuous modeling of water level changes in response to barometric pressure variations to identify when the signals are reliable and then determine values of aquifer transmissivity and aquitard hydraulic diffusivity. Computed aquifer transmissivity agrees with values from well tests. We obtain horizontal and vertical hydraulic parameters for more than 10 years (from 2008 to 2019). Of the six wells studied, five have aquitard vertical hydraulic diffusivities at least two orders of magnitude greater than aquifer horizontal transmissivity. Although several regional and teleseismic earthquakes caused changes in water levels in one of the wells with relatively low vertical permeability, we do not see clear changes in hydraulic properties in response to the earthquakes. We also identify small long‐term trends and seasonal variations in hydrogeological properties. Plain Language Summary Surface water and shallow groundwater can infiltrate into deeper aquifers used to supply water. Quantifying this leakage is important for assessing the risk of contamination and managing water resources. One way to measure leakage and to monitor how it might change over time, is to record how variations in atmospheric pressure caused by weather modify water levels in wells. Pressure variations at the surface affect pressure at depth and lead to groundwater flow. By monitoring water level changes, it is thus possible to determine properties of the subsurface and leakage from aquifers. We apply this approach to a set of wells in China in a groundwater system that provides water to >20 million people. We find that reliable estimates of subsurface properties can be obtained from atmospheric pressure variations over time periods greater than about one day. Over the 10‐year period we study, we also find no significant changes in subsurface properties. Key Points Continuous hydraulic properties obtained from barometric response of water level with improved calculation method Vertical leakage found in Jurassic Shaximiao shallow crust, aquifer properties from on‐site pumping tests match barometric calculations Chuan‐Yu shallow groundwater susceptible to contamination from surface sources

Despite having approximately 100,000 lakes, Sweden has limited continuous gauged lake water level data. Although satellite radar altimetry (RA) has emerged as a popular alternative to measure water levels in inland water bodies, it has not yet been used to understand the large-scale changes in Swedish lakes. Here, we quantify the changes in water levels in 144 lakes using RA data and in situ gauged measurements to examine the effects of flow regulation and hydroclimatic variability. We use data from several RA missions, including ERS-2, ENVISAT, JASON-1,2,3, SARAL, and Sentinel-3A/B. We found that during 1995-2022, around 52% of the lakes exhibited an increasing trend and 43% a decreasing trend. Most lakes exhibiting an increasing trend were in the north of Sweden, while most lakes showing a decreasing trend were in the south. Regarding the potential effects of regulation, we found that unregulated lakes had smaller trends in water level and dynamic storage than regulated ones. While the seasonal patterns of water levels in the lakes in the north are similar in regulated and unregulated lakes, in the south, they differ substantially. This study highlights the need to continuously monitor lake water levels for adaptation strategies in the face of climate change and understand the downstream effects of water regulatory schemes.Energy production and water consumption have led to the regulation of many lakes in Sweden. To understand the consequences of human activities, we studied water level changes in 144 regulated and non-regulated lakes, utilizing satellite data. We found that regulated lakes show larger water level changes and variability compared to non-regulated ones. These findings underscore the need for effective adaptation strategies to mitigate the impacts of water regulatory schemes.Increasing lake water level trends in 52% of all lakes and decreasing in 43% of them Increasing water level trends in northern Sweden and decreasing in the south Different Water level seasonal patterns in regulated and non-regulated lakes in the South.

The coseismic response of a well’s water level and the degree of rock damage in response to earthquakes can be quantified and used to understand the mechanism of the response of the aquifer system. The coseismic response of well water levels has been reported to be related to aquifer permeability, and this relationship is influenced by seismic events. Hydraulic parameters of the aquifer were obtained from the coseismic response of the water level in Well X10 in Xinjiang, China, before and after three local earthquakes from December 2016 to August 2020, and were used to estimate the degree of rock damage caused. Results indicated that the hydraulic parameters and primary rock defects (e.g., microcracks and microvoids) changed by varying degrees. It is suggested that the coseismic response of the water level caused by local earthquakes is the result of the coupling between volume and deviator strains. It was concluded that earthquake-induced stress changes in the fracture zone were likely to lead to changes in the rock damage areas and alterations in its multiple elastic parameters, while the changes in the hydraulic parameter were relatively small. Evolution of rock defects was found to depend on initial stress level, initial damage state, and coseismic strain in the aquifer, indicating that the mechanism of the earthquake-induced coseismic response of the water level is complex. These findings contribute to a deeper understanding of the earthquake-induced deformation of an aquifer and the mechanism of the coseismic response of the groundwater.

A high-resolution and low-cost image-based water level sensor was developed using an image processing algorithm. The sensor measures water levels in six channels simultaneously. The image processing algorithm automatically identifies water level images and determines the water levels by analyzing the brightness of the images. The measured water levels were verified by comparison with the calibrated water levels using known length standards. The performance test results of the developed water level sensor were compared with those of commercial water level sensors, demonstrating a superior resolution of 0.06 mm and an inexpensive cost of USD 80. In addition, the developed sensor demonstrated an accuracy of 0.9%, a stability of 0.3%, an adjustable measurement range, and an instantaneous response time. In conclusion, the image-based water level sensor that was developed provides a reliable method for real-time visual monitoring of water levels in six channels simultaneously.

On 15 January 2022, the largest eruption of the Hunga‐Tonga volcano in recorded history produced a plume registered by multi‐parametric instruments around the world. However, the far‐field hydrogeological responses to Lamb waves from this eruption remain underexplored. We studied the responses of groundwater to the volcanic eruption in the far‐field over 8,700 km, including 274 wells. Results show that the Lamb waves with a speed of 316 m/s affects the groundwater system, leading to similar fluctuations in well water level (WL) and opposite phase fluctuation in borehole strain. Different wells exhibit diverse responses in WL amplitudes, possibly for heterogeneities in local aquifer systems. Gain values of 5 wells that simultaneously measure atmospheric pressure, borehole air pressure, borehole strain and WL are consistent with results obtained through cross‐power spectrum estimation. This work demonstrates a novel response in far‐field groundwater systems induced by Lamb waves and expects application for aquifer parameter estimation. Plain Language Summary The massive eruption of the Hunga‐Tonga volcano on 15 January 2022 generated shock waves in the Earth's atmospheric layer, known as Lamb waves, which propagated at the boundary of air and the solid Earth. While many studies reported multi‐parameter responses during or after the eruption, the response of the groundwater system has not been studied. In this study, we found that Lamb waves from the volcano eruption induced similar phase responses in the water levels of 256 wells within the 274‐well network and opposite phase responses in borehole strain in mainland China. Additionally, the Lamb wave induced a possible time lag in the response of well water level (WL) and horizontal strain, which may be caused by different hydraulic properties of the wells. In the five wells with common observations, the calculated atmosphere pressure sensitivity is consistent with previous studies. The response of well WL to the Lamb wave is obviously different compared to that observed during co‐seismic events and Earth tides. Key Points The Lamb wave from the Hunga‐Tonga volcano eruption induces similar phase responses in the water level (WL) of 256 wells in the far field Responses of well WL and borehole strain to the Lamb wave show a possible time‐delay relative to that of atmosphere pressure The incorporation of the WL parameter and horizontal transverse strain is recommended to calibrate the appropriate models