Dead Sea and Arava Science Center

ABSTRACT Crises have the potential to significantly disrupt travel and tourism. However, tourism has shown a remarkable ability to recover, highlighting its resilience and adaptive capacity. Tourism resilience refers to the way tourism systems successfully absorb a crisis, using their adaptive capacity to reorganize and bounce forward. This study examines the resilience of the tourism demand system, focusing on how travelers adapt their plans in response to crises. Using a case study of travel during a crisis, the research employs social media sentiment analysis to understand outbound travel dynamics and their level of adaptability. The study identifies three key themes concerning the adaptive capacity of travel demand: new considerations in destination selection, increased emphasis on flexibility and cancelation policies, and changes in travelers' motivations. These findings shed light on the adaptive capacity of tourism demand, contributing to the emerging literature on tourism resilience and the dynamic nature of travel demand.

Abstract Single‐ and multi‐thread gravel‐bed ephemeral channels in semi‐arid and arid regions have a characteristic repeating, channel‐wide pattern of low angle, fine‐grained ‘flats’ alternating with steeper, coarse‐grained ‘bars’. The genesis of these macroforms, while a topic of ongoing discussion, has not been fully elucidated. We have documented the formation of these macroforms after both artificially homogenising the bed material of a reach of the Nahal Yatir in the northern Negev, Israel, and ensuring its surface was planar. Here, we integrate the empirical data gained from these field experiments with a novel mathematical model. The model we propose, within a one‐dimensional framework, is based on the analysis of flow over an initially planar, erodible bed consisting of a bimodal grain size mixture of sediment. We apply linear stability analysis to derive a solution that provides insight into the formational dynamics of these macroforms. Our results indicate that bar‐flat patterns may arise from a free‐instability mechanism driven by sediment size heterogeneity, provided that the standard deviation of the sediment grain size distribution (GSD) is sufficiently large. Application of the model to a selection of ephemeral channels of the northern Negev suggests that repeating bar‐flat patterns are likely to develop during the recession of flash flood hydrographs, specifically when flow conditions approach the critical threshold for bedload transport. Besides providing a possible explanation for the formation of these macroforms, this study also contributes to a broader understanding of geomorphic processes in dryland river systems.

In this research, different Mg chips were produced via a mechanical chipping method in air to explore their potential as hydrogen storage materials. The production of fine magnesium chips was achieved with a laboratory-scale milling device, while coarse magnesium chips were fabricated by using a standard milling machine. The investigation of the first hydrogenation, at 300 °C under 50 atm, reveals that the fine chips require a shorter activation period of turbomolecular vacuum evacuation at 300 °C and exhibit a higher hydrogen absorption rate than the coarse chips. The activation stage anneals the dislocations formed during milling; therefore, they do not contribute to the hydrogenation. The enhanced performances of the fine chips are attributed to their larger specific surface area, smaller thickness, and the presence of macrostructural defects. Surface analysis of the outermost layers of the Mg chips, before and after activation procedures, sheds light on the surface reactions and thermal processes enabling the initiation of hydrogen absorption in Mg chips. The first hydrogen absorption kinetics appear to be characterized by a low-dimensional nucleation and growth mechanism. Apparent activation energies for absorption and desorption, determined using the Avrami and Kissinger equations, respectively, fall within the reported range for absorption and are lower than those reported for desorption. The mechanical chipping method in air is a simpler alternative to ball milling for producing Mg chips for hydrogen storage applications but requires an activation period before hydrogenation.

Students in peripheral areas often score lower in the sciences than those in urban areas. This study explores the feasibility of distance learning in making quality science education accessible everywhere. In 2016, the Israeli government established technological infrastructure in southern peripheral schools, but these resources remained largely unused. From 2018 to 2019, we interviewed school principals and education department directors, and surveyed teachers and students about distance learning. The findings showed hesitance among educators to implement distance learning for expanding science subjects, despite their confidence in using it when necessary. After the mandatory shift to distance learning during the COVID-19 pandemic in 2020, attitudes towards technology in remote schools improved. Barriers to implementing distance learning were found to be mainly due to internal factors like preconceived notions, which limited the development of necessary skills among teachers and students. We recommend addressing internal resistance to distance learning in teacher training programs.

Anthropogenic habitat modification can indirectly effect reproduction and survival in social species by changing the group structure and social interactions. We assessed the impact of habitat modification on the fitness and life history traits of a cooperative breeder, the Arabian babbler (Argya squamiceps). We collected spatial, reproductive and social data on 572 individuals belonging to 21 social groups over 6 years and combined it with remote sensing to characterize group territories in an arid landscape. In modified resource-rich habitats, groups bred more and had greater productivity, but individuals lived shorter lives than in natural habitats. Habitat modification favoured a faster pace-of-life with lower dispersal and dominance acquisition ages, which might be driven by higher mortality providing opportunities for the dominant breeding positions. Thus, habitat modification might indirectly impact fitness through changes in social structures. This study shows that trade-offs in novel anthropogenic opportunities might offset survival costs by increased productivity.

Abstract We calibrated an acoustic pipe microphone system to monitor bedload flux in a sandy, gravel‐bed ephemeral channel. Ours is a first attempt to test the limit of an acoustic surrogate bedload system in a channel with a high content of sand. Calibrations varied in quality; significant data subsetting was required to achieve R2 values >0.75. Several data quality issues had to be addressed: (1) apparent pulses, which occur when a sensor records an impulse from sediment impacting the surrounding substrate rather than directly impacting the sensor, were frequent, especially at higher signal amplifications. (2) The impact sensors were frequently covered by gravel sheets. This prompted the development of a cover detection protocol that rejected part of the impact sensor record when at least one sensor was partially or fully covered. (3) Because of the lack of sensor sensitivity to impacts of sand‐sized particles, which was anticipated, and the considerable sand component of bedload in this channel, a grain size‐limited bedload flux was estimated. This was accomplished by sampling the bedload captured by slot samplers and evaluating the variation of grain size with increasing flow strength. This considerably improved the results when compared to attempts at estimating the flux of the entire distribution of grain sizes. This calibration is a successful first attempt, though the impact sensors required several site‐specific calibration steps. A universal set of equations using impact sensors to estimate bedload transport of fine‐gravel with a large content of sand remains elusive. Notwithstanding, our study demonstrates the utility of impact sensor data, producing relatively low root mean square errors that are independent of measurements of flow strength (i.e. discharge). These tools will be particularly useful in settings that would benefit from new methodologies for estimating bedload transport in sand‐rich gravel‐bed rivers, such as the American desert Southwest.

The use of Electric vehicles (EV) as a sustainable transport system has many issues connected with the acquisition of essential materials like lithium, cobalt, and nickel. This paper aims to highlight the environmental and social impacts of the EV supply chain and then evaluate the sustainability strategies that are being implemented to address them. The research also measures the carbon footprint, resource depletion, and ecological effects of raw material extraction and production processes through a lifecycle assessment (LCA). A social effect assessment is also conducted to examine the employment rights and liberties and displacement of communities within the mining regions. The transition to EVs and the comparison between EVs and Internal Combustion Engine Vehicles are highlighted in this section to expose the advantages and disadvantages of the change. The study also evaluates the efficiency of international measures and responsible sourcing norms such as the Organization for Economic Co-operation and Development (OECD) Due Diligence Guidance. As it has been pointed out in this study, while the use of EVs may offer opportunities for environmental benefits, social and ecological concerns are still left unsolved, thereby requiring greater collaboration along the supply chain for sustainability and social justice.

Abstract. One of the greatest threats to groundwater is contamination from fuel derivatives. Benzene, a highly mobile and toxic fuel derivative, can easily reach groundwater from fuel sources and lead to extensive groundwater contamination and drinking water disqualification. Modelling benzene transport in the unsaturated zone can provide quantification of the risk for groundwater contamination and needed remediation. Yet, characterization of the problem is often complicated, due to typical soil heterogeneity and numerous unknown site and solute parameters, as well as the difficulty in distinguishing important from non-important parameters, resulting in high uncertainty. Thus, the application of sensitivity analysis (SA) methods, such as global SA (GSA), is required to reduce uncertainty and detect important parameters for groundwater contamination, mitigation, and remediation. Nevertheless, studies devoted to identification of the driving parameters for fuel derivatives transport in the unsaturated zone are scarce. Here, we performed GSA on a problem of benzene transport in the unsaturated zone. First, a simple GSA ‘Morris’ screening method was used for a homogenous sandy vadose zone. Then, a more computationally-demanding ‘Sobol’ variance-based GSA was run on the most influential parameters. Finally, the ‘Morris’ method was tested for a heterogeneous medium containing clay layers. To overcome the problem of model crashes during GSA, several methods were tested for imputation of missing data. The GSA results found benzene degradation rate (λk) to be the utmost influential parameter controlling benzene mobility. The depth of aquifer followed in importance in the homogenous media, while in the heterogeneous media parameters related to the clay layers, such as clay adsorption coefficient and the number of clay layers, followed in importance. The study emphasizes the significance of λk and the presence of clay layers in predicting aquifer contamination. The study also strengthen the importance of heterogenous media representation in the GSA, since different parameters control the transport in different soil layers. Overall, GSA is demonstrated here as an important tool for the analysis of transport models. The results also show that in higher dimensionality models, the radial basis function (RBF) is an efficient surrogate model for missing data imputation.

Abstract The forecasted increased frequency and intensity of extreme climatic events may strongly affect ecosystem structure and function in the future. It is unclear how ecosystems will function in the long run over a large spatial scale under a new extreme water cycle. This open question calls for a conceptual framework as a fundamental basis for theoretical and experimental exploration of ecosystem function on a large scale driven by an extreme climate envelope. To assess the problem on a large scale, we investigated hyper‐arid ecosystems (HAEs) as natural tangible models that already function under an extreme climatic envelope. Our new assertion is that if extreme climate change drives arid lands to function under alternate extreme conditions, then arid land ecosystems will function like an HAE as an alternative state, rather than progress to desertification. To support our assertion, we developed a conceptual framework of HAEs that includes a geo‐hydrological “abiotic engine” that drives HAE function by soil moisture diversity and plant functional groups. Based on this conceptual framework, we suggest incorporating two new hypotheses in climate change studies to advance our understanding of responses of large‐scale, water‐limited ecosystems: (1) Hydro‐climatic extremes in water‐limited ecosystems will reduce the degree of resource conservation by slope ecosystems due to reduction in plant cover and soil. The decreased ecosystem function on the slope will be compensated for by increasing the effect of the abiotic engine on the ephemeral stream, thus enhancing meta‐ecosystem functioning in the ephemeral stream. (2) In water‐limited ecosystems, climate change toward hydro‐climatic extremes will rescale the dominant hydro‐ecological processes of pulse–reserve, source–sink, and connectivity along the semiarid, arid, and HA gradients in two ways: (i) shrinking of both spatial and temporal dimensions; and (ii) shrinking in the temporal dimension and expanding in the spatial dimensions. The first rescaling trajectory is related to biodiversity–ecosystem function and the second to the abiotic engine processes.