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The management of groundwater in densely populated areas with no centralized water treatment is critical for the prevention of diseases and maintaining sanitation. Here, we determine the bacteriological and chemical characteristics of groundwater in Kabul city, a resource that 4.1 million individuals rely on. Groundwater samples were analyzed from 41 newly established piezometric wells across Kabul, and data were compared with the last detailed study, undertaken in 2007, to understand contamination trends in an area that has undergone significant development and social changes. Piper diagrams, Gibbs diagrams, correlation analysis, and bivariate plots examine the hydrogeochemical and natural occurring processes of groundwater. The average concentration of cations followed the order Na+ > Mg2+ > Ca2+ > K+, and anions HCO3− > NO3− > Cl− > SO42− > F with Gibbs diagrams indicating mainly rock-weathering influence groundwater chemistry. An increase in nitrate (NO3−) and E. coli indicates anthropogenic activities impacting the shallow groundwater quality, with significantly elevated nitrate (over 50 mg/L) and E. coli (up to 250 CFU/100 mL). The increasing presence of E. coli and NO3− in the shallow groundwater of Kabul city in turn suggests problematic links to the prevalence of waterborne diseases. Additionally, the water quality index (WQI) was used to assess groundwater quality, and rank its suitability for drinking purposes. The WQI analysis showed that less than 35% of shallow groundwater samples had good water quality. The findings of this study are crucial for the development and sustainable management of groundwater in the city. In short term, we propose interventions such as point-of-use (POU) water purification which may offer temporary respite for waterborne disease prevention. Kabul city requires immediate attention to developing sustainable groundwater management policies, expansion of the water supply network, groundwater quality monitoring, and wastewater management.

Friction is one of the types of interaction between bodies. It occurs when two bodies touch. The forces acting between the surfaces of contacting solids are called dry friction forces. They are always directed tangentially to the touching surfaces and are divided into the forces of friction at rest, sliding and rolling. The friction forces depend on many factors that accompany the movement of bodies in the presence of friction. In this regard, the description of friction forces is possible only with the help of empirically found approximate laws, which are often quite rough. The rest friction force is a variable value, it can change from zero to a certain maximum value. By applying a force to the body that exceeds the maximum resting friction force, we will move the body from its place, and it will begin to move. The article considers examples of motion in which the friction force can be mistakenly interpreted as a driving force. The nature of the forces of friction at rest and rolling is considered from the perspective of modern physical materials science.

Both climate change and anthropogenic activities contribute to the deterioration of terrestrial water resources and ecosystems worldwide, with Central Asia and its endorheic lakes being among the most severely affected. We used a digital elevation model, bathymetry maps and Landsat images to estimate the areal water cover extent and volumetric storage changes for eleven small terminal lakes in Burabay National Nature Park (BNNP) in Northern Kazakhstan from 1986 to 2016. Based on the analysis of hydrometeorological observations, lake water balance, lake evaporation and Budyko equations, driven by gridded climate and global atmospheric reanalysis datasets, we evaluate the impact of historical climatic conditions on the water balance of the BNNP lake catchments. The total surface water area of the BNNP lakes decreased by around 7% for that period, mainly due to a reduction in the extent of three main lakes. In contrast, for some smaller lakes, the surface area increased. Overall, we attribute the decline of the BNNP lakes’ areal extent and volume to the prolonged periods of water balance deficit when lake evaporation exceeded precipitation. However, during the most recent years (2013–2016) precipitation increased and the BNNP lake levels stabilized.

Burabay National Nature Park (BNNP), which is famous for its beautiful lakes and pine forests, is an important tourist destination and biodiversity hot spot in cold, semi-arid Northern Kazakhstan, Central Asia. BNNP lake system is being influenced by increasing anthropogenic pressures and climate change impacts. Lake level declines observed from 2008 to 2013 followed by rebound from 2013 onwards raised concerns about the future of these unique lakes. Previous studies on BNNP lakes showed that its steady long-term water storage decline was mainly due to a natural water balance deficit, with evaporation (from the lakes and catchments) exceeding precipitation. Next, to obtain a deeper understanding of this complex lake system, we studied the BNNP’s catchments by applying a hydrological model. This work is the first attempt to simulate the hydrological processes in two key BNNP lakes (Ulken Shabakty and Burabay) using a semi-distributed hydrological model, Soil and Water Assessment Tool (SWAT). The available daily lake level measurements were transformed into lake volumes using the data from a recent bathymetric survey and Surface Volume tool of ArcGIS. The level of Burabay Lake is determined by its main outlet, Gromotukha river, that discharges the excess water from Burabay Lake to Ulken Shabakty. Therefore, it acts as a natural reservoir and allows to use the Reservoir function of SWAT. Calibration of the model by lake volumes was done for years 2010-2013 and the model performed well for both lakes (NSE 0.71 and 0.57; KGE 0.77 and 0.73; PBIAS -0.9 and -0.4 for Ulken Shabakty and Burabay, respectively). However, during validation for years 2014-2016 the model performance decreased considerably (NSE -23.94 and -0.35, KGE 0.12 and -0.35, PBIAS 7.6 and -0.3 for Ulken Shabakty and Burabay, respectively). SWAT substantially overestimated the lake volumes for Ulken Shabakty by 0.01 km3 on average for the validation period. This extreme overestimation highlights the specific features of both basins, which has to do with the local subsurface flows. Due to the relatively simplistic representation of groundwater in SWAT and the absence of comprehensive groundwater data, the calibrated model might not have been able to fully capture the complexity of the actual hydrogeologic system. As a result, smaller in size surface catchment boundary (in the case of Ulken Shabakty Lake) is considered in comparison to potentially larger groundwater catchment boundary. In addition, two years (2010 and 2012) used for calibration were drought years, during which the model might have compensated for the lower groundwater flows by simulating enhanced surface runoff and lateral flow. As a result, during the following years with normal and higher precipitation amounts (2013-2016) significantly higher surface runoff was generated. Further studies using coupled groundwater and surface water models are necessary to understand the interactions between groundwater and surface water.

The occurrence of both natural and man-made disasters is inescapable, but the consequences for the lives of vulnerable communities can be mitigated. United Nation (UN) and organizations such as the Federal Emergency Management Agency (FEMA) recommend investing proactive rather than re-active actions in dealing with disasters. It is commonly understood that “$1 spent on risk reduction saves between $5 and $10 in economic losses from disasters.” Currently Central Asian countries including Kazakhstan have weak proactive support programs and disaster mitigation plans. Most of the support activities are post disaster. Proactive actions, monitoring and prediction analysis of the potential disasters in Kazakhstan and other Central Asian countries require a multidisciplinary cooperative approach with applications of remote sensing sensor monitoring technologies. These require a permanent energy supply in various harsh environmental conditions. What advance energy storage systems are available and can be used for a Disaster Resilience programs? How can these energy storage systems be integrated into remote sensing sensor monitoring technologies? Our group of researchers is developing the multidisciplinary Disaster Resilience Institute ( www.drinu.org ) and Laboratory to Monitor Engineering Constructions (LaMEC, www.lamec.org ) to work on proactive monitoring actions related to engineering facilities that are interconnected to surface and underground water resources such as bridges, dams, and reservoirs. We are looking for the cooperation in these areas and are convinced that success is presaged on a multidisciplinary approach.

Snow cover plays an important role in the hydrological cycle and water management in Kazakhstan. However, traditional observations do not meet current needs. In this study, a snow depth retrieval equation was developed based on passive microwave remote sensing data. The average snow depth in winter (ASDW), snow cover duration (SCD), monthly maximum snow depth (MMSD), and annual average snow depth (AASD) were derived for each year to monitor the spatial and temporal snow distributions. The SCD exhibited significant spatial variations from 30 to 250 days. The longest SCD was found in the mountainous area in eastern Kazakhstan, reaching values between 200 and 250 days in 2005. The AASD increased from the south to the north and maintained latitudinal zonality. The MMSD in most areas ranged from 20 to 30 cm. The ASDW values ranged from 15 to 20 cm in the eastern region and were characterized by spatial regularity of latitudinal zonality. The ASDW in the mountainous area often exceeded 20 cm.

Both climate change and anthropogenic activities contribute to the deterioration of terrestrial water resources and ecosystems worldwide. Central Asian endorheic basins are among the most affected regions through both climate and human impacts. Here, we used a digital elevation model, digitized bathymetry maps and Landsat images to estimate the areal water cover extent and volumetric storage changes in small terminal lakes in Burabay National Nature Park (BNNP), located in Northern Central Asia (CA), for the period of 1986 to 2016. Based on the analysis of long-term climatic data from meteorological stations, short-term hydrometeorological network observations, gridded climate datasets (CRU) and global atmospheric reanalysis (ERA Interim), we have evaluated the impacts of historical climatic conditions on the water balance of BNNP lake catchments. We also discuss the future based on regional climate model projections. We attribute the overall decline of BNNP lakes to long-term deficit of water balance with lake evaporation loss exceeding precipitation inputs. Direct anthropogenic water abstraction has a minor importance in water balance. However, the changes in watersheds caused by the expansion of human settlements and roads disrupting water drainage may play a more significant role in lake water storage decline. More precise water resources assessment at the local scale will be facilitated by further development of freely available higher spatial resolution remote sensing products. In addition, the results of this work can be used for the development of lake/reservoir evaporation models driven by remote sensing and atmospheric reanalysis data without the direct use of ground observations.

Water resources in Central Asia are scarce, so complicated issues arise from this. Kazakhstan is a Central Asian landlocked country which has mostly closed drainage basins, characterized by endorheic lakes that do not drain to the oceans. These endorheic lakes are very sensitive to climate change and anthropogenic influences. Very few studies have been conducted on the hydrological cycle of the small endorheic lakes. This work reviews the endorheic lakes within Burabay National Nature Park (BNNP), Northern Kazakhstan. BNNP is a small ecozone consisting of terminal lakes watersheds covered by mixed forests and grasslands. These endorheic lakes have been drying out during the last one hundred years or so with the water level decrease accelerated in the past few decades. According to historical observations (1935-2014), on the one hand precipitation amounts did not significantly change, while on the other hand, air temperature steadily increased. The lake level decrease is most probably caused by a water budget deficit, with evaporation exceeding the precipitation inputs in the long-term. The direct anthropogenic impact (water abstraction) plays a minor role in deterioration of water levels, with most significant impacts through localized land use changes such as road and building construction in the catchments. The future of the park’s sensitive ecosystems in a changing climate is uncertain; therefore, BNNP requires modern ecohydrological monitoring methods and analysis tools to improve our understanding of its hydrological cycle variability, and to enable us to develop adequate adaptation and mitigation measures.

In Enterobacteriaceae, the ProP protein, which takes up proline and glycine betaine, is subject to a post-translational control mechanism that increases its activity at high osmolarity. In order to investigate the osmoregulatory mechanism of the Salmonella enterica ProP, we devised a positive selection for mutations that conferred increased activity on this protein at low osmolarity. The selection involved the isolation of mutations in a proline auxotroph that resulted in increased accumulation of proline via the ProP system in the presence of glycine betaine, which is a competitive inhibitor of proline uptake by this permease. This selection was performed by first-year undergraduates in two semesters of a research-based laboratory course. The students generated sixteen mutations resulting in six different single amino acids substitutions. They determined the effects of the mutations on the growth rates of the cells in media of high and low osmolarity in the presence of low concentrations of proline or glycine betaine. Furthermore, they identified the mutations by DNA sequencing and displayed the mutated amino acids on a putative three-dimensional structure of the protein. This analysis suggested that all six amino acid substitutions are residues in trans-membrane helices that have been proposed to contribute to the formation of the transport pore, and, thus, may affect the substrate binding site of the protein.

Highly productive wells in the Central Eastern Desert of Egypt are tapping groundwater in subsided blocks of Jurassic to Cretaceous sandstone (Taref Formation of the Nubian Sandstone Group) and Oligocene to Miocene sandstone (Nakheil Formation), now occurring beneath the Red Sea coastal plain and within the proximal basement complex. Aquifer development is related to Red Sea rifting: (1) rifting was accommodated by vertical extensional displacement on preexisting NW-SE– to N-S–trending faults forming a complex array of half-grabens and asymmetric horsts; and (2) subsided blocks escaped erosion accompanying the Red Sea–related uplift. Subsided blocks were identifi ed and verifi ed using satellite data, geologic maps, and fi eld and geophysical investigations. Interpretations of very low frequency (VLF) measurements suggest the faults acted as conduits for ascending groundwater from the subsided aquifers. Stable isotopic compositions (δD: –19.3‰ to –53.9‰; δ 18 O: –2.7‰ to –7.1‰) of groundwater samples from these aquifers are interpreted as mixtures of fossil (up to 70%) and modern (up to 65%) precipitation. Groundwater volumes in subsided blocks are large; within the Central Eastern Desert basement complex alone, they are estimated at 3 × 10 9 m 3 and 10 × 10 9 m 3 for the

This manuscript presents major, minor and trace elements data for groundwater samples collected from wells, tube wells, springs and karezes from Quetta Valley. Quetta Valley in Pakistan has frequently experienced shortage of groundwater. In recent years, the water quality has had a sharp decline at many locations. The study of groundwater resources in this valley is an attempt to understand the causes of and sources of contamination. At several locations, nitrate, sulfate, arsenic, selenium, chromium and nickel contamination has been determined. The preliminary results indicate that these contaminations apparently result from a combination of rock alteration and mining activity in the area. Different water sources could have also contributed to the deterioration of the water quality of Quetta Valley. This research provides the basis for future work, which will involve detailed hydrological modeling and water quality studies.

Cape Cod, an early North American colony, was covered by mature forest prior to European contact but, with settlement in the late seventeenth century, aeolian processes dominated into the twenty-first century. An aerial photographic time series from AD 1938 to 2003 quantifies dune movement that reflects processes over centuries and documents accelerated parabolic dune movement at ~4 m/yr from 1938 to 1977 during a drier interval. In contrast, dune movement between 1987 and 2003 slowed to ~1 m/yr with wetter conditions. Wetlands expand post dune movement often forming in dune blowouts with seasonally wet conditions. Stratigraphic studies, coupled with optically stimulated luminescence ages, place erosion and burial of the pre-settlement forest soil by migrating dunes at AD 1690 ± 40 yr, with aeolian deposition continuing into the nineteenth and twentieth centuries, consistent with the historic record of land surface conditions. A threshold of landscape stability was exceeded in the late seventeenth to early eighteenth centuries, indicated by dune formation in response to human-induced land-cover changes, concomitant severe droughts and exposure to tropical storm/hurricane windfield. Dune orientation indicates preferential movement during winter with winds dominantly from the W—NW and with reduced vegetation cover. The present high biodiversity in interdunal wetlands is a legacy of aeolian processes from landscape disturbance initiated by European settlers in the seventeenth century.

Summary Chemical and stable isotopic compositions of groundwater samples from the Rub Al Khali (RAK) in southern Saudi Arabia were analyzed. Samples were collected from wells of variable depth (1.5–800 m) along the perimeter of the eastern half of the RAK including flowing artesian wells, pumped wells (formerly artesian), and shallow hand-dug wells encompassing those in sabkha areas. Data indicate that the water from the artesian and formerly artesian wells represents the contents of confined aquifers. Such water (Group 1) is isotopically depleted (δ2H values ranging from −60‰ to −35‰), and has total dissolved solids (TDS) concentrations ranging from 1300 to 76,000 mg/L, indicating that much of the salinity is acquired in the subsurface. Water from shallow hand-dug wells including those in sabkha areas (Group 2) has experienced significant evaporation (δ2H values ranging from −34‰ to +19‰) as well as salinization (TDS as high as 92,000 mg/L) by dissolution of sabkha salts including halite and gypsum. Stable isotope data for the Group 2 water samples define an evaporation trend line originating from the Group 1 water samples. This relationship indicates that the Group 2-type water evolved from Group 1-type water by ascending through structural discontinuities, dissolving evaporative salts, and undergoing substantial near-surface evaporation in groundwater discharge zones (sabkhas) characterized by shallow groundwater levels (

Water resources in Central Asia are scarce, so complicated issues arise from this. Kazakhstan is a Central Asian landlocked country, which has mostly closed drainage basins, characterized by endorheic lakes that do not drain to the oceans. These endorheic lakes are very sensitive to climate change and anthropogenic influences. Very few studies have been conducted on the hydrological cycle of the small endorheic lakes. This work reviews the endorheic lakes within Burabay National Nature Park (BNNP), Northern Kazakhstan. BNNP is a small ecozone consisting of terminal lakes watersheds covered by mixed forests and grasslands. These endorheic lakes have been drying out during the last one hundred years or so with the water level decrease accelerated in the past few decades. According to historical observations (1935–2014), on the one hand precipitation amounts did not significantly change, while on the other hand, air temperature steadily increased. The lake level decrease is most probably caused by a water budget deficit, with evaporation exceeding the precipitation inputs in the long term. The direct anthropogenic impact (water abstraction) plays a minor role in the deterioration of water levels, with most significant impacts through localized land-use changes such as road and building construction in the catchments. The future of the park's sensitive ecosystems in a changing climate is uncertain; therefore, BNNP requires modern ecohydrological monitoring methods and analysis tools to improve our understanding of its hydrological cycle variability, and to enable us to develop adequate adaptation and mitigation measures. For further resources related to this article, please visit the WIREs website.