Spring Locations Research Articles

Spatial and temporal variation of CBPI and leakage of heavy metals from cigarette butts into the urban environment

More than 5 trillion cigarettes are produced in the world every year. This hazardous waste is one of the most important litter in the environment. The purpose of this study was to investigate the density and dispersion of cigarette butts in the urban environment and to estimate the leakage of pollution from it to the environment. For this purpose, the cigarette butt pollution index was used in 14 locations. Observations were made during a year and once a month for each location. The study of the locations was done with the same conditions on weekend and working days. The amount of heavy metal leakage was estimated based on the average weight of cigarette butts and the ratio of metal leakage in different weather conditions. The results showed that the annual average of index for the studied locations was 1.36 (SD 0.11) to 10.6 (SD 1.23). Based on this, 28.5% of the locations were in the low pollution status and 42.8% were in the significant pollution status and worse. On average, the index on weekend decreased by 32.3 percent in all locations, and the average index of the studied locations in spring and summer was 26.2 percent higher than in autumn and winter. The average leakage of heavy metals including chromium, cadmium, zinc, lead, copper, and nickel from littered cigarette butts in commercial, residential, and recreational areas was estimated to be 0.27, 0.079, and 0.17 µg per square meter, respectively. Cigarette butt is one of the most abundant litter in the studied area, which is the source of many pollutants, including heavy metals. This hazardous waste is a serious threat to the urban environment.

Associations between temperature variations and tourist arrivals: analysis based on Baidu Index of hot-spring tourism in 44 cities in China.

Hot-spring tourism refers to entertainment, health preservation, commercial conferences, and other leisure activities at hot-spring locations. This tourism often shows periodic variability, which may be due to seasonal temperature variations. However, studies on the effects of temperature variations on tourist arrivals at hot springs are limited. Therefore, this study aimed to evaluate this relationship in 31 provincial capital cities and 13s-tier cities in China. Using the Baidu Index, we obtained data for tourist arrivals to hot springs in each city and constructed a generalised additive model to explore the associations between temperature variations and tourist arrivals. We also analysed the statistical significance of the estimated effects during different seasons to explore potential effect modification. A 1°C increase in temperature was associated with a 1.81% (95% confidence interval (CI): 1.69-1.93) decrease in daily tourist arrivals for hot-spring tourism. Significant positive associations between the abovementioned factors were observed in summer (2.18% change, 95% CI: 1.32-3.04). The effect of temperature on the volume of tourist arrivals may last for approximately 2months. Robustness analysis confirmed the data reliability. The results indicate that significant relationships exist between temperature variations and hot-spring tourism arrivals, which vary seasonally. This study has significant implications for travel agencies to effectively manage tourist visits to hot spring locations.

Land cover and NDVI are important predictors in habitat selection along migration for the Golden-crowned Sparrow, a temperate-zone migrating songbird

BackgroundMigrating passerines in North America have shown sharp declines. Understanding habitat selection and threats along migration paths are critical research needs, but details about migrations have been limited due to the difficulty of tracking small birds. Recent technological advances of tiny GPS-tags provide new opportunities to delineate fine-scale movements in small passerines during a life stage that has previously been inherently difficult to study.MethodsWe investigated habitat selection along migration routes for a temperate-zone migratory passerine, the Golden-crowned Sparrow (Zonotrichia atricapilla), given GPS tags on California wintering grounds. We used a resource selection function combined with conditional logistic regression to compare matched sets of known stopover locations and available but unused locations to determine how land cover class, vegetation greenness and climate variables influence habitat selection during migration. We also provide general migration descriptions for this understudied species including migration distance, duration, and elevation, and repeated use of stopover areas.ResultsWe acquired 22 tracks across 19 individuals, with a total of 541 valid spring and fall migration locations. Birds traveled to breeding grounds in Alaska and British Columbia along coastal routes, selecting for shrubland and higher vegetation greenness in both migration seasons as well as grasslands during fall migration. However, model interactions showed they selected sites with lower levels of greenness when in forest (both seasons) and shrubland (fall only), which may reflect their preference for more open habitats or represent a trade-off in selection between habitat type and productivity. Birds also selected for locations with higher daily maximum temperature during spring migration. Routes during spring migration were lower in elevation on average, shorter in duration, and had fewer long stopovers than in fall migration. For two birds, we found repeated use of the same stopover areas in spring and fall migration.ConclusionsUsing miniaturized GPS, this study provides new insight into habitat selection along migration routes for a common temperate-zone migrating songbird, contributing to a better understanding of full annual cycle models, and informing conservation efforts. Golden-crowned Sparrows selected for specific habitats along migration routes, and we found previously unknown behaviors such as repeated use of the same stopover areas by individuals across different migratory seasons.

Identification of Spring Distribution in the Pusur Sub-Watershed and Surroundings Using Geographic Information System

Groundwater is the water that originates from the surface and infiltrates the ground, forming a hydrological system. The presence of groundwater is influenced by various factors, including climate conditions, geomorphology, geology, human activities, and land cover conditions. The Pusur Sub- Watershed area is part of the Bengawan Solo Watershed, and it is known to have a distribution of spring sources with varying levels of productivity. The presence of spring sources provides benefits for fulfilling needs in various sectors of life. This study aims to identify the distribution of springs and the productivity levels of aquifers in the Pusur Sub-Watershed area. The method used involves conducting surveys and ground checks of spring locations in the Pusur Sub-Watershed area. Subsequently, the spring distribution information is overlaid with a hydrogeological map. The results of the analysis indicate that the aquifer productivity in the Pusur Sub-Watershed area is divided into five categories: moderate productivity, moderate-localized productivity, high productivity, widespread productivity, and localized-localized productivity. The highest concentration of springs is found in the Polanharjo, Tulung, and Jatinom Districts, categorized as high productivity. Meanwhile, in the Musuk and Tamansari Districts, sprin†gs are also found in the localized-localized productivity category

Modern dextral strain controls active hydrothermal systems in the southeastern Canadian Cordillera

Thermal springs in the southeastern Canadian Cordillera occur in association with several major fault zones, which may permit deep circulation of fluid through fractured reservoirs to depths greater than 2 km. Both the current stress field and the most recent kinematics of these faults likely play a significant role in localizing hydrothermal upwellings but are poorly resolved. In this paper, we present new data from structural mapping along the Columbia River, Slocan Lake, Purcell Trench, Southern Rocky Mountain Trench, and Redwall faults. Fault plane and slickenfiber orientations measured in the field indicate a previously unidentified, post-Eocene phase of dextral strike-slip kinematics on these faults, which have historically been mapped primarily as Eocene extensional structures. The NE−SW maximum principal stress required for these kinematics shares a similar orientation to the present-day stress field derived from crustal earthquake focal mechanisms, which suggests dextral slip may be a recent and ongoing development that continues at the present time. On a regional scale, there is a positive correlation between the locations of springs and regions with elevated seismicity. At the local scale, geothermal upwellings may be controlled by local zones of enhanced permeability including fault intersections and strain-transfer zones. The identification of favorable structural settings may enable discovery of hidden (a.k.a. blind) geothermal energy resources.

Assessment of groundwater potential modeling using support vector machine optimization based on Bayesian multi-objective hyperparameter algorithm

Today, water supply in order to achieve sustainable development goals is one of the most important concerns and challenges in most countries. For this reason, accurate identification of areas with groundwater potential is one of the important tools in the protection, management and exploitation of water resources. Accordingly, the present study was conducted with the aim of modeling and predicting groundwater potential in Markazi province, Iran using Multivariate adaptive regression spline (MARS) and Support vector machine (SVM) machine learning models and using two random search (RS) and Bayesian optimization hyperparameter algorithms to optimize the parameters of the SVM model. For this purpose, 18 variables affecting the groundwater potential and 3482 spring locations were used to model the groundwater potential. Data for modeling were divided into two categories of training (70%) and validation (30%). The receiver operating characteristics (ROC) were used to evaluate the performance of the models. The results of evaluation models showed that using hyperparameters random search and Bayesian optimization were improved SVM accuracy in training and validation stages. Bayesian optimization methods are very efficient because they are consciously choosing the parameters of the model that this strategy improves the performance of the model. Evaluating accuracy in the validation stage showed that the AUC value is for MARS, SVM, RS-SVM and B-SVM models 87.40%, 88.25%, 90.73% and 91.73%, respectively. The results of assessment variables importance showed elevation, precipitation in the coldest month, soil and slope variables have the most importance in modeling groundwater potential, while aspect, profile curvature and TWI variables, have the least importance in predicting groundwater potential in Markazi province.

Structural analysis of fracture networks controlling geothermal activity in the northern part of the Malawi Rifted Zone from aeromagnetic and remote sensing data

We investigated the relationship between the geothermal activity and fracture networks that control storage and fluid pathways of geothermal systems in the northern part of the Malawi Rifted Zone (MRZ). It is suggested that low to medium temperature geothermal systems in the MRZ are mainly non-magmatic and structurally controlled. However, structural controls and favorable settings of geothermal activity are poorly understood in this region. We used an approach of remote sensing and aeromagnetic data analysis to 1) identify and characterize fracture networks to better understand the structural controls of geothermal activity in the northern part of the rift, 2) quantify and identify permeable areas using topological analysis of fracture intensity and connectivity frequency proxies, 3) understand the role that inherited structures play in the geothermal systems of the northern part of the rift, and 4) build preliminary geothermal conceptual models of selected geothermal systems. Our findings show that fracture networks in the Karonga and Nkhata regions comprise a varying degree of complexity along strike. This structural complexity occurs mainly in favorable structural settings such as 1) two fault segments coalescing to form hard and soft-linked relays, 2) two different oriented fracture segments intersecting each other, and 3) on the tips of major normal faults. The hot springs are located where one or more of these favorable settings occur. The remote sensing analysis shows that Quaternary normal faults are the primary controlling structures of thermal waters at shallow depths in the Karonga (NW-SE to N-S strike) and Nkhata (N-S strike) regions. The aeromagnetic data revealed that permeable NW-striking foliation planes of the Precambrian Mugesse Shear Zone and WNW to ENE-striking foliation planes of the Mwembeshi Shear Zone are important structural controls of geothermal fluids at greater depths in the Karonga and Nkhata region, respectively. The Mwankeja-Mwesia and Chiweta geothermal systems in the Karonga region show favorable structural settings for geothermal fluids related to NNW and NW-striking normal faults segments that coalesce to form hard and soft-linked relay ramps and NW, and NNE -striking faults intersecting each other and NW-striking foliation planes. The Mtondolo geothermal area in the Nkhata region shows that the intersection of N-striking normal faults and ENE-striking foliation planes is the favorable structural setting that controls the emergence of hot springs through the surface. We conclude that high fracture intensity and connectivity are related to the location of the hot springs at the surface and can be used to determine permeable zones and hidden geothermal fluids together with other methodologies. The aeromagnetic data analysis suggested that buried faults and inherited structures (e.g., foliation planes) are controlling the geothermal fluids at depth. Additionally, our aeromagnetic analysis of magnetic basement depth estimation suggests that some of the geothermal reservoirs in the northern part of the MRZ could have an estimated depth of ~ 500 to 1000 m.b.g.l. Finally, the low-cost methodology applied in this study can reduce the risk of drilling non-productive wells in the early exploration stages and become an exploration strategy for similar geothermal systems in countries of the Western Branch of the East African Rift System.

Dating springlines from hydrogeological and archaeological evidence

AbstractThe relationship between prehistoric populations and water is often poorly understood, partly as a function of historical reliance on qualitative and fragmentary datasets in many regions. Here, we adopt a quantitative approach to analyze a specific aspect of the relationship between prehistoric populations and water for the Cotswold Hills, southwest UK; an area of documented hydrogeological change and extensive Neolithic (ca. 5.5 ka) activity. Using a database of all known Neolithic monuments, we interrogate the significance of water to their habitation. By marshaling a large dataset of recent (ca. 100 years) changes in the discharge and elevation of 259 springs, we establish a striking negative relationship between present-day spring discharge and annual elevation change. We then formulate an inverse problem to predict spring elevations in Neolithic times. Spring elevations are predicted to be closer to, and higher than, Neolithic-dated sites relative to the location of modern springs. These results emphasize a utilitarian and/or reverential link between water and prehistoric populations. Our approach of reconciling markedly different datasets and timescales can easily be adapted to other regions. While groundwater had behaved reasonably predictably since Neolithic times, recent human activity is (and will continue to be) far more significant in influencing groundwater behavior.

Spring efficiency assessment and efficient use of spring methods of statically balanced planar serial manipulators with revolute joints only

Abstract. This paper proposes a spring efficiency assessment of a statically spring-balanced planar serial manipulator. The admissible spring configurations for the static balancing of planar serial manipulators without auxiliary links have been determined in the past. Gravity is balanced by the spring configuration systematically; however, the spring configuration also contains counter-effects between springs. Conceptually, with fewer counter-effects between springs, there is less burden on the spring system, which means that the springs are used more efficiently, and accordingly, the system would be safer, and its service life would be longer. In this study, the spring energy is represented in a quadratic form. The coefficients in a quadratic form represent the change in elastic energy with the relative position between links, which is named “elastic pseudo-stiffness”. Compared to the quadratic form of gravity energy, those elastic pseudo-stiffnesses for static balancing are regarded as positive contributions of a spring, while those that contain counter-effects are seen as negative ones. Spring efficiency is defined as the ratio of the elastic pseudo-stiffnesses, which has positive contributions for balancing to total elastic pseudo-stiffnesses. To use springs efficiently, the counter-effects, which are functions of spring parameters, need to be decreased, including spring stiffness and the attachment location of springs on links. A method to use spring efficiently by adjusting spring parameters is developed. Furthermore, it is found that, for a spring attached between adjacent links, the spring efficiency is 100 %, and the spring efficiency decreases while the number of joints over which the spring spans increases. In a spring manipulator system, the efficiency is negatively correlated to the payload. As an example, an efficiency assessment on a 3 degrees of freedom (DOF) manipulator is shown at the end.

Identification of shallow groundwater in arid lands using multi-sensor remote sensing data and machine learning algorithms

The focus of this study is to locate shallow groundwater (SGW) occurrences in arid lands using the Western Desert (WD; area: ∼680,000 km2) of Egypt as a test site. The SGW in the study area originated from paleo-precipitation during previous wet climatic periods. In wet periods, fossil groundwater was at higher levels, ascended along high-angle faults, and discharged at the surface. In contrast, at present, the water levels are lower, and the discharge occurs at near-surface elevations. Spring locations were identified as the dependent variable, while the independent variables included remote sensing–based variables and geomorphological features indicative of current or paleo discharge locations, including elevation, slope, curvature, distance to sapping features, soil moisture, NDVI, radar backscatter coefficient, and brightness temperature. Relationships between SGW occurrences (target) and their controlling factors (independent variables) were established using extreme gradient boosting (XGB), support vector machine (SVM), and logistic regression (LR) methods. The trained models were used to map SGW locations across the entire WD. Findings include the following: (1) the XGB yielded the most favorable result in identifying SGW locations (overall accuracy: 0.93) compared to SVM (overall accuracy: 0.88) and LR (overall accuracy: 0.87); (2) areas with a very high probability of SGW occurrences were found in lowlands and proximal to sapping features; (3) the overwhelming majority of the cultivated lands within the southern and central sections of the WD lie within areas identified as high and very high probability SGW locations; (4) our models identify-two previously unrecognized major SGW occurrences, an eastern zone (EZ; length: 800 km; width: 9 to 80 km; area: 43,000 km2) and an east–west trending northern zone (NZ) centered over the Qattara depression (length: 500 km; width: 200 km; area: 62,150 km2); (5) additional criteria were used to refine the modeled (XGB) SGW distribution (southern and central WD: 43,200 km2 to 23,400 km2; EZ: from 21,300 km2 to 17,400, and NZ: from 62,150 to 30,700 km2) including presence of shallow aquifers to accommodate rising Nubian waters, Nubian water salinity (fresh to brackish), and low to moderate thickness (<1 km) of post-Nubian successions that rising waters interact with. The techniques are cost-effective and efficient and could be readily applied to large sectors of Saharan Africa and Arabia, whose landscape and fossil aquifers bear many resemblances in their geologic, climatic, and geomorphic characteristics to the Nubian Sandstone Aquifer System.

Characterisation of intertidal springs in a faulted multi-aquifer setting

In intertidal zones, groundwater is often present as seepage that provides freshwater and nutrients to marine ecosystems. Point discharge or springs in intertidal zones have been observed in many locations, often in the form of sand boils. The spatial extent, temporal variability and source of intertidal springs are rarely documented and typically, not well understood. This study examined four intertidal groundwater springs at Sellicks Beach, South Australia, during May 2017, November 2019 and September 2020 using a combination of hydrogeophysical methods. A thermal infrared survey undertaken in 2017 showed springs as groupings of closely spaced sand boils that were warmer (15 °C) than the surrounding saturated beach sediments (7 °C). The four springs ranged in diameter from 0.20 to 0.45 m. Electromagnetic geophysical surveys identified a resistive anomaly (3.5 to 5.0 ohm.m), assumed to represent freshwater upwelling at the location of a spring, that extended 10 m horizontally and at least 6.7 m vertically. The average electrical conductivity of water discharging from the springs was 18.4 mS/cm, while seawater was 54.8 mS/cm. δ18O and δ2H data from the springs showed a variation between winter and spring, likely caused by variations in mixing ratios between seawater and groundwater. The springs are proximal to major regional fault systems that likely create preferential flow paths that control spring location and flow rates. The observations of spring characteristics highlight the critical role of seawater-groundwater mixing ratios, preferential flow paths and tidal variations in creating temporal variability in spring discharge and salinity.

Groundwater input drives large variance in soil manganese concentration and reactivity in a forested headwater catchment

AbstractIn headwater catchments, surface groundwater discharge areas have unique soil biogeochemistry and can be hot spots for solute contribution to streams. Across the northeastern United States, headwater hillslopes with surface groundwater discharge were enriched in soil Mn, including Watershed 3 of Hubbard Brook Experimental Forest, New Hampshire. Soils of this site were investigated along a grid to determine extent of Mn‐rich zone(s) and relationships to explanatory variables using ordinary kriging. The O and B horizons were analyzed for total secondary Mn and Fe, Cr oxidation potential, total organic C, moisture content, wetness ratio, and pH. Two Mn hot spots were found: a poorly drained, flowing spring (Location A); and a moderately well‐drained swale (Location B). Both had ∼6,000–9,000 mg Mn kg–1 soil. However, Location A had high Cr oxidation potential (a measure of Mn reactivity), whereas Location B did not. Location C, a poorly drained seep with slow‐moving water, had lower Mn content and Cr oxidation potential. Manganese‐rich soil particles were analyzed using X‐ray absorption near‐edge structure and micro‐X‐ray diffraction; the dominant oxidation state was Mn(IV), and the dominant Mn oxide species was a layer‐type Mn oxide (L‐MnO2). We propose input of Mn(II) with groundwater, which is oxidized by soil microbes. Studies of catchment structure and response could benefit from identifying hot spots of trace metals, sourced mainly from parent material but which accumulate according to hydropedologic conditions. Small‐scale variation in Mn enrichment due to groundwater and microtopography appears to be more important than regional‐scale variation due to air pollution.

Double-beam metastructure with inertially amplified resonators for flexural wave attenuation

A new type of double-beam metastructure with periodically attached inertially amplified (IA) resonators is designed to attenuate the flexural wave propagation in the low-frequency range. An analytical approach based on the spectral element method (SEM) and the Wittrick-Williams algorithm is developed. The results of SEM show superior accuracy and an order of magnitude higher computational efficiency compared to the finite element method (FEM). Employing the developed approach, the wave attenuation behavior is presented as a function of the parameters including truss angle, beam thickness, IA mass, spring, and damper location to exhibit the perfect adjustability of bandgaps realized by the proposed structure. The local resonance bandgap frequencies are effectively lowered under the effect of inertial amplification. In addition, the damping amplification is also achieved by the IA structure, which is advantageous for extending the wave attenuation range. Finally, multibody dynamics numerical simulations are carried out to validate the reliability of the theoretical method and the rationality of simplifications used in the theoretical derivation. Furthermore, the formation mechanism of bandgaps is revealed by exploring the eigenmode shape on dispersion curves to obtain a thorough understanding of the structure.

Effect of sampling duration on culturable and viable bioaerosol determination when using Rutgers Electrostatic Passive Sampler (REPS)

Rutgers Electrostatic Passive Sampler (REPS) is a passive bioaerosol sampler composed of a permanently polarized polyvinylidene fluoride (PVDF) film wound into a 3D printed film holder. In order to investigate the effect of sampling duration on its performance, REPS was deployed in an indoor and outdoor location in Spring and Fall over continuing sampling periods ranging from 24 h to 21 days. Reference concentrations were determined by an active, culture-based sampler twice daily. REPS samples were analyzed for culturable bacteria and fungi as well as adenosine triphosphate (ATP) activity. The number of culture forming units (CFU) determined by REPS exhibited strong and positive correlations with sampling duration for culturable bacteria (Pearson r > 0.899, p < 0.05) and fungi (r > 0.902, p < 0.05) for both test locations. Similar results were observed for ATP activity in outdoor samples (r > 0.844, p < 0.05). REPS showed an equivalent flow rate (Qeq) as high as 4.86 ± 4.90 L/min when sampling bacteria outdoors. When sampling bacteria indoors, the Qeq was lower: 0.37 ± 0.78 L/min. When sampling fungi, the Qeq outdoors was also higher than that indoors. Overall, the study demonstrated that REPS is able to effectively capture airborne culturable bacteria and fungi by passive means of collection in indoor and outdoor environments while maintaining bioaerosol culturability for over 21 days of continuous sampling. Further studies will explore methods to improve the sample detection limit by using different sample concentration techniques as well as the sampler's integration with the next-generation sequencing techniques.

Modeling a fractured geothermal reservoir using 3-D AMT data inversion: Insights from Garibaldi Volcanic Belt, British Columbia, Canada

An audio-magnetotelluric (AMT) survey was conducted to explore for shallow geothermal resources in the Garibaldi Volcanic Belt, the location of which has the highest geothermal potential in Canada. The data cover the south Meager geothermal system, including Pylon Peak and Meager Creek which have proven borehole temperatures exceeding 250 °C. A dimensionality analysis of the AMT data suggests complex 3-D subsurface structure. The 3-D resistivity model of the area shows two high conductivity features near surface in the areas south of Pylon Peak and north of Meager Creek, both of which are related to hydrothermal alteration. These layers act as the caprock and connect close to the surface. The conductive zones reach surface near the locations of warm springs along Meager Creek. Clay cap layers are interpreted to consist mainly of smectite, illite and rare kaolinite with the resistivities below 15 Ωm in our model. The caprock overlays fractured quartz diorite permeated by hot water. This hot fluid reservoir is related to a higher resistivity feature coinciding with high temperature zones at a depth of approximately 1 km below sea level. This model illustrates possible conduits through which the hydrothermal fluids were transported to thermal springs at the surface. This research shows that integrating the AMT model, geology, and temperature data is crucial to build a conceptual model of the Mount Meager geothermal system to support targeted drilling by industry.

Application of machine learning to groundwater spring potential mapping using averaging, bagging, and boosting techniques

Abstract Determining groundwater potential is vital for groundwater resource management. This study aims to present a comparative analysis of three widely used ensemble techniques (averaging, bagging, and boosting) in groundwater spring potential mapping. Firstly, 12 spring-related factors and a total of 79 groundwater spring locations were collected and used as the dataset. Secondly, three typical ensemble models were adopted to predict groundwater spring potential, namely, Bayesian model averaging (BMA), random forest (RF), and the gradient boosting decision tree (GBDT). The area under the receiver operating characteristics curve (AUC) and four statistical indexes (accuracy, sensitivity, specificity, and the root mean square error (RMSE)) were used to estimate the model's accuracy. The results indicate that the three models had a good predictive performance and that the AUC values of the GBDT, RF, and BMA were 0.88, 0.84, and 0.78, respectively. Furthermore, the GBDT had the best performance (accuracy = 0.89, sensitivity = 0.91, specificity = 0.87, and RMSE = 0.33) in terms of the four indexes, followed by RF (accuracy = 0.87, sensitivity = 0.91, specificity = 0.83, and RMSE = 0.36) and BMA (accuracy = 0.76, sensitivity = 0.87, specificity = 0.65, and RMSE = 0.49). This research can provide effective guidance for using ensemble models for mapping groundwater spring potential in the future.

STABILITY AND DYNAMIC ANALYSES OF PIPE CONVEYED FLUID STIFFENED BY LINEAR STIFFNESS ELEMENT USING FINITE ELEMENTS METHOD

Different types of dynamic instability of the system occur when the flow velocity exceeds a specific value; thereby the problem of dynamic instability of the pipe conveyed flow became shining. Several effective parameters play an important role in stabilizing the system, such as stiffness addition. In this search, dynamic analysis of pipe conveying fluid stiffened by linear spring was studied using the finite element method. The effect of stiffness addition (linear spring) and the effect of spring location was deeply studied. Also, the effect of flow velocity on the dynamic stability of the system was taken into the consideration. It was observed that there is a critical flow velocity after which the system loses its stability. There is a critical spring constant at which the dynamic behavior becomes more sensitive. Also, there is a specific spring location (effective location) so the spring offers the best results for the frequency of the system. Effective spring locations depend on the flow velocity and spring constant itself. The effective spring location was found to be arranged from x/l= 0.7 to 1.

Integrating GIS and remote sensing for delineation of groundwater potential zones in Bundelkhand Region, India

The present research aims to find the groundwater prospective areas by using Geographic Information System and Remote Sensing based frequency ratio technique. The data sets that affect groundwater such as geomorphology, lithology, slope, soil, rainfall, drainage density, lineament density and land use/ land cover were taken under consideration for finding the groundwater prospective areas in the Bundelkhand region, India. Thematic maps of all the above-mentioned factors have been prepared from the remotely sensed data, data taken from the different organizations and departments. The weights of each attribute class of each thematic layer are assigned according to the frequency ratio technique. A total, 799 numbers of spring locations and discharge rate data of 108 numbers of well locations have been taken under consideration for obtaining the frequency ratio of each attribute class of every parameter used and testing the obtained result, respectively. Finally, all layers were combined by raster calculator command in ArcGIS software to develop the map of groundwater prospective zones in the Bundelkhand region. The produced groundwater prospective areas were classified into five different zones such as very high, high, moderate, low and very low prospective zones and verified by actual well yield data.

The effect of river regulation on groundwater flow patterns and the hydrological conditions of an aapa mire in northern Finland

Study regionNorthern Finland. Study focusThis study examined long-term (decade-scale) hydrological and ecological consequences of dam construction and subsequent river regulation on the environmentally protected Viiankiaapa mire. Pre-regulation floods affected the hydrology of the riverbanks and the Viiankiaapa mire, which contain habitats of flood-dependent or groundwater-influenced ecosystems. Groundwater discharge and flow patterns and pre-regulation flood coverage were simulated to investigate the impact of river regulation on the mire area. New hydrological insights for the regionThe flood models indicate that regular flooding covered the westernmost part of the mire before the regulation. Groundwater modelling suggests that the regulation has raised the locations of springs in the river shore, reduced the hydraulic gradient towards the river, raised the groundwater table in the river banks and the western part of the Viiankiaapa mire, and increased groundwater discharge in the mire. The groundwater flow models and the stable isotopic composition of water indicate that the constructed dam changed the groundwater flow directions close to dam. The ecological effects of regulation were mixed: the studied flood-dependent plant species declined due to the reduction in floods after regulation. Conversely, the occurrence of Hamatocaulis vernicosus and Hamatocaulis lapponicus appears to be related to the high water table and groundwater discharge areas in the mire, suggesting suitable habitat for these species may have expanded after the regulation.

Debarking intensity of European bison in the Bieszczady Mountains in relation to forest habitat features

The damage to trees that is caused by ungulate species is a natural result of their presence in ecosystems. High densities of ungulates may have a negative effect on biodiversity and the regeneration and survival of trees. The aim of this study was to identify the factors that affect the probability of the occurrence of damage in forest stands as a result of the presence of European bison (Bison bonasus). We collected data on the presence of European bison in given locations in winter and spring of 2020; this data also concerned damage to trees, forest stand characteristics, and densities of other ungulates.European bison was the most important debarking agent. Within the home range of the European bison, 344 forest stands were damaged, which represented 43.5% of all stands. The most frequent damage was bark stripping, 35.9%. The most important factors in terms of bark damage were canopy cover, dominating tree species, dominating tree age, and distance to a feeder. More debarking occurred in stands with open canopies, and coniferous species were more likely to be damaged than broadleaved species. Frequency of damage in forest stands with dominating Norway spruce was higher than 0.5, whereas for forest stands with silver fir and Scots pine it was over 0.4. Other coniferous species also presented a relatively high proportion of damage (0.38). The results of our study indicate a need for rational damage-prevention measures in the ranges of other free-living wisent populations that live in managed forests.