The hydraulic jump is a typical sudden change for mountain river areas. The effects of local hydraulic jumps on the particle transport capacity decrease and local flow resistance increase cannot be ignored as the sediment deposition disaster can amplify the flash flood disaster. The present research investigates the influences of a hydraulic jump on the individual particle movement and sediment deposition in a laboratory flume. The overall processes of a single particle movement are captured by a high-speed camera. The distribution of sediment deposition along the hydraulic jump is obtained statistically. The results show that both the particle size and the ratio of the upstream and downstream Froude numbers affect the particle motion process. A single particle coming from upstream gradually decelerates and finally stops at the hydraulic jump section because of hydraulic jump resistance. The particle acceleration first increases and then decreases during the time-domain process, and the attenuation trends are fast with the increase of ratio of upstream and downstream of Froude numbers. The increase of the maximum acceleration with sediment flows follows a linear trend approximately, which indicates that the kinetic features of the single sand particle are determined by the coupling effects of the hydraulic jump resistance and the sand dynamic properties. With the increase of sediment rate and sand particle size, the resistance effect of hydraulic jump on sediment deposition rate along the flow direction gets strong and the sediment deposition area is mainly located upstream of the hydraulic jump region. The present study shows that the possible sediment supply upstream must be obtained for identifying the disaster risk combined with the local hydraulic jump conditions. Further researches about the detailed critical condition deduced from the relationship between the water flow and sediment deposition are required to confirm and extrapolate present results to other applications.

Bird diversity is often used as surrogates for other species diversity, but there is a limited understanding of the extent of this surrogate in identifying representative priority conservation areas(PCAs). We used Yunnan Province in China as a case to measure the surrogacy of birds in systematic conservation planning. Here, we collected distribution records of mammals, amphibians, reptiles, and birds from public databases and literature, and applied systematic conservation planning methods to identify PCAs. We targeted four taxonomic groups at conservation targets of 17%, 31%, and 50% of the total study area, and used the Jaccard similarity index to evaluate the surrogate extent of bird PCAs for the other three groups. Then, we overlapped different portfolios of PCAs with six categories of protected areas(PAs) in Yunnan, calculated the protection rates,and evaluated the effect of sustainable-use PAs on improving the protection rate of strict Nature Reserves. The results showed that bird PCAs generally had the highest surrogacy for representing PCAs of the other three taxa. At the 50% conservation target, the Jaccard indices between birds and the other taxa reached about 0.50. Moreover, amphibian PCAs had a good surrogacy for conserving reptiles, with a Jaccard index of 0.30, 0.44 and 0.51 at the 17%, 31% and 50% conservation targets, respectively. The existing PA system had quite low coverages for PCAs of these four taxa, and the average protection rates were 22.97%, 19.78% and 16.52% at the three levels of conservation targets, respectively. The sustainable-use PAs can greatly complement the strict Nature Reserves by achieving average increased PA coverages of 10.00%, 9.20% and 7.90% at the three conservation targets. Our findings provide a basis for surrogate-based conservation planning for areas with insufficient biodiversity information.

To protect and promote the originality and authenticity of mountain foodstuffs, the European Union set Regulation No 1151/2012 to create the optional quality term "mountain product". Our research aimed at exploring the attractiveness of the mountain product label for consumers, considering both attitude towards the label itself and purchase intentions. We propose a model to investigate relationships between four latent constructs-mountain attractiveness, mountain food attractiveness, attitude towards the mountain product label, and purchase intention-which have been tested, thus confirming the statistical relevance of the relationships. All 47 items selected for describing the latent constructs are suitable for this purpose. Ridge and LASSO results also show that 17 items of the first three constructs are relevant in explaining purchase intentions. Some contextual variables, such as age, income, geographical origin of consumers, and knowledge of mountain products and mountains for tourism purposes, can positively influence consumers' behavior. These findings could support the design of mountain development strategies, in particular marketing actions for both the product and the territory.

High-density resistivity imaging method is widely used in landslide monitoring. The resistivity of rock and soil is closely related to factors, such as porosity, moisture content, saturation and temperature. In this study, the resistivity test was designed to investigate the influence of physical factors and pore solution components on the resistivity of landslide soil. Experimental and analytical results find that both moisture content and volumetric water content varies greatly under the same resistivity. At different temperatures, soil resistivity exhibits great changes. Under the same temperature, the ion concentration and species in pore solutions have great influence on soil resistivity. Based on the test results and grey correlation analysis,this study established a resistivity model by considering porosity, saturation, temperature and ion concentration. The study lays a foundation for the high-density resistivity method to measure the moisture content of landslides.

Three-dimensional(3D)printing technology is increasingly used in experimental research of geotechnical engineering. Compared to other materials, 3D layer-by-layer printing specimens are extremely similar to the inherent properties of natural layered rock masses. In this paper, soft-hard interbedded rock masses with different dip angles were prepared based on 3D printing(3DP) sand core technology. Uniaxial compression creep tests were conducted to investigate its anisotropic creep behavior based on digital imaging correlation(DIC)technology. The results show that the anisotropic creep behavior of the 3DP soft-hard interbedded rock mass is mainly affected by the dip angles of the weak interlayer when the stress is at low levels. As the stress level increases, the effect of creep stress on its creep anisotropy increases significantly, and the dip angle is no longer the main factor. The minimum value of the long-term strength and creep failure strength always appears in the weak interlayer within 30°–60°, which explains why the failure of the layered rock mass is controlled by the weak interlayer and generally emerges at 45°. The tests results are verified by comparing with theoretical and other published studies. The feasibility of the 3DP soft-hard interbedded rock mass provides broad prospects and application values for 3DP technology in future experimental research.

The staggered distribution of joints and fissures in space constitutes the weak part of any rock mass. The identification of rock mass structural planes and the extraction of characteristic parameters are the basis of rock-mass integrity evaluation, which is very important for analysis of slope stability. The laser scanning technique can be used to acquire the coordinate information pertaining to each point of the structural plane, but large amount of point cloud data,uneven density distribution, and noise point interference make the identification efficiency and accuracy of different types of structural planes limited by point cloud data analysis technology. A new point cloud identification and segmentation algorithm for rock mass structural surfaces is proposed. Based on the distribution states of the original point cloud in different neighborhoods in space, the point clouds are characterized by multi-dimensional eigenvalues and calculated by the robust randomized Hough transform(RRHT). The normal vector difference and the final eigenvalue are proposed for characteristic distinction, and the identification of rock mass structural surfaces is completed through regional growth, which strengthens the difference expression of point clouds. In addition, nearest Voxel downsampling is also introduced in the RRHT calculation, which further reduces the number of sources of neighborhood noises, thereby improving the accuracy and stability of the calculation. The advantages of the method have been verified by laboratory models. The results showed that the proposed method can better achieve the segmentation and statistics of structural planes with interfaces and sharp boundaries. The method works well in the identification of joints, fissures, and other structural planes on Mangshezhai slope in the Three Gorges Reservoir area, China. It can provide a stable and effective technique for the identification and segmentation of rock mass structural planes, which is beneficial in engineering practice.

The Fraction of Absorbed Photosynthetically Active Radiation(FPAR) is an important indicator of the primary productivity of vegetation. FPAR is often used to estimate the assimilation of carbon dioxide in vegetation. Based on MOD15 A2 H/FPAR data product, the temporal and spatial variation characteristics and variation trend of FPAR in different vegetation types in 2001 to 2018 were analyzed in the Hengduan Mountains. The response of FPAR to climate change was investigated by using Pearson correlation analytical method and partial least squares regression analysis. Results showed that the FPAR in Hengduan Mountains presented an increasing trend with time. Spatially, it was high in the south and low in the north, and it also showed obvious vertical zonality by elevation gradient.The vegetation FPAR was found to be positively correlated with air temperature and sunshine duration but negatively correlated with precipitation. Partial least squares regression analysis showed that the influence of sunshine duration on vegetation FPAR in Hengduan Mountains was stronger than that of air temperature and precipitation.

Rock creep properties can be used to predict the long-term stability in rock engineering.In reservoir bank slopes,sandstones which are frequently used in the bank slope undergoing longterm effects of dry-wet(DW) cycles due to periodic water inundation and drainage may gradually accumulate creep deformation,resulting in rock structure's damage or even geological hazards such as landslides.To fully investigate the effect of DW cycles on the creep damage properties of sandstone,triaxial creep tests were conducted on saturated sandstone with different DW cycles by using a triaxial rheometer apparatus.The experimental results show that both the instantaneous strain and the stabilized strain increase with the DW cycles.In addition,using the Burgers model,four kinds of functions including an exponentially decreasing function,a linearly decreasing function,a linearly increasing function and an exponentially increasing function were proposed to express the relationships between the shear modulus,viscoelastic parameters of the Burgers model and the deviatoric stress under different DW cycles.Through comparative analysis,it is found that the theoretical curves generated using proposed four kinds of functions are in good agreement with the experimental data.Furthermore,macromorphological and microstructural observations were performed on specimens after various triaxial rheological tests.For samples with small number of DW cycles,approximately X-shaped fracture surfaces were observed in shear failure zones,whereas several shear fractures including obvious axial and horizontal tensile cracks,and flaws were found for samples with relatively large DW cycles due to long-term propagation and evolution of micro-fissures and micro-pores.Furthermore,as the DW cycles increases,the variation in micro-structure of samples after creep failure was summarized into three stages,namely,a stage with good and dense structure,a stage with pore and fissure propagation,and a stage with extensive increase of pores,fissures and loose particles.It is concluded that the combination effect of permeation of water molecules through pores and fissures within sandstone,and the propagation of preexisting pores and fissures owing to the dissolution of mineral particles leads to further deterioration of the mechanical properties of sandstone as the number of DW cycles increases.This study provides a fundamental basis for evaluating the long-term stability of reservoir bank slopes under cyclic fluctuations of water level.

In the restoration of degraded wetlands, fertilization can improve the vegetation-soilmicroorganisms complex, thereby affecting the organic carbon content. However, it is currently unclear whether these effects are sustainable. This study employed Biolog-Eco surveys to investigate the changes in vegetation characteristics, soil physicochemical properties, and soil microbial functional diversity in degraded alpine wetlands of the source region of the Yellow River at 3 and 15 months after the application of nitrogen, phosphorus, and organic mixed fertilizer. The following results were obtained: The addition of nitrogen fertilizer and organic compost significantly affects the soil organic carbon content in degraded wetlands. Three months after fertilization, nitrogen addition increases soil organic carbon in both lightly and severely degraded wetlands, whereas after 15 months, organic compost enhanced the soil organic carbon level in severely degraded wetlands. Structural equation modeling indicates that fertilization decreases the soil p H and directly or indirectly influences the soil organic carbon levels through variations in the soil water content and the aboveground biomass of vegetation. Three months after fertilization, nitrogen fertilizer showed a direct positive effect on soil organic carbon. However, organic mixed fertilizer indirectly reduced soil organic carbon by increasing biomass and decreasing soil moisture. After 15 months, none of the fertilizers significantly affected the soil organic carbon level. In summary, it can be inferred that the addition of nitrogen fertilizer lacks sustainability in positively influencing the organic carbon content.

This research aimed to identify the impact of local climatic and topographic conditions on the formation and development of the ice cover in highmountain lakes and the representativeness assessment of periodic point measurements of the ice cover thickness by taking into consideration the role of the avalanches on the icing of the lakes. Field works included measurement of the ice and snow cover thickness of seven lakes situated in the Tatra Mountains(UNESCO biosphere reserve) at the beginning and the end of the 2017/2018 winter season. In addition, morphometric, topographic and daily meteorological data of lakes from local IMGW(Polish Institute of Meteorology and Water Management) stations and satellite images were used. The obtained results enabled us to quantify the impact of the winter eolian snow accumulation on the variation in ice thickness. This variation was ranging from several centimetres up to about 2 meters and had a tendency to increase during the winter season. The thickest ice covers occurred in the most shaded places in the direct vicinity of rock walls. The obtained results confirm a dominating role of the snow cover in the variation of the ice thickness within individual lakes.

National parks are highly valuable natural areas and have the potential to attract a large number of visitors.The number of visitors at national parks is systematically increasing,often exceeding Tourism Carrying Capacity(TCC) of trails.This situation requires adjusting the number of park visitors to adapt to sustainable management systems of visitor flow,thus preventing or counteracting overtourism.The aim of the study is to propose a comprehensive method for tourists monitoring in mid-mountain national park presented on the example of the Sto?owe Mountains National Park(SMNP) in Poland,called as Monitoring System of tourist traffic(MSTT).The study describes six stages procedure of tourists Monitoring System creation and application as an optimal measurement technique.The MSTT enabled a multidimensional analysis of tourist traffic in SMNP.With the help of 39 pyroelectric sensors and surveys data spatio-temporal characteristic of visitor flow was obtained.The data generated in MSTT included hourly,daily,weekly,monthly,and annual reports,taking into account the direction of traffic measuring both directions:entries(IN),exits(OUT) and passages(IN+OUT).The results from pyroelectric sensors were supplemented with field surveys,where visitor's motivations,preferences,and behaviours were determined.In 2017 a total of 871,344 visitors were recorded in SMNP what causes one of the most popular national parks in Poland.The SMNP is a suitable destination for short breaks leisure visits in wilderness.In order to sustain MSTT methodology in the long-run the set of guidelines together with the workload estimates were presented.In the future,the MSTT can be further developed,including monitoring of climbing,cycling,cross-country skiing,car traffic and illegal tourism assessment.The MSTT can be considered as a useful tool for tourism management in mid-mountain national parks throughout the entire calendar year.

Soil quality determination and estimation is an important issue not only for terrestrial ecosystems but also for sustainable management of soils. In this study, soil quality was determined by linear and nonlinear standard scoring function methods integrated with a neutrosophic fuzzy analytic hierarchy process in the micro catchment. In addition,soil quality values were estimated using a support vector machine(SVM) in machine learning algorithms. In order to generate spatial distribution maps of soil quality indice values, different interpolation methods were evaluated to detect the most suitable semivariogram model. While the soil quality index values obtained by the linear method were determined between 0.458-0.717, the soil quality index with the nonlinear method showed variability at the levels of 0.433-0.651. There was no statistical difference between the two methods, and they were determined to be similar. In the estimation of soil quality with SVM, the normalized root means square error(NRMSE) values obtained in the linear and nonlinear method estimation were determined as 0.057 and 0.047, respectively. The spherical model of simple kriging was determined as the interpolation method with the lowest RMSE value in the actual and predicted values of the linear method while, in the nonlinear method, the lowest error in the distribution maps was determined with exponential of the simple kriging.

Studying the population ecology of endangered plants provides important baseline information for its monitoring and conservation.Juniperus phoenicea L. is an endangered species in arid ecosystems in Africa and the Middle East. The static life tables, survival curve and age structure of J.phoenicea populations from two mountains in North Sinai, Egypt(Gabal(G.) El-Halal and G. El-Maghara)were investigated. In each mountain, fifteen plots were selected, and field measurements such as stand density, tree height, and crown diameter were conducted. Moreover, 44 trees were cored and crossdated according to standard dendrochronological procedures. The results showed that the tree ages ranged from 50 to 262 years at G. El-Halal and 96 to431 years at G. El-Maghara. Mature J. phoenicea individuals dominated the study area, with only a few individuals being younger than 100 years. Moreover,seedling recruitment was extremely limited. Since the studied J. phoenicea populations showed high mortality rates among both old and young individuals,there is an imminent need for establishing a conservation program to prevent its extinction in the future. Therefore, management and conservation efforts should be made to minimize human disturbance and protect the relic habitats of this endangered species at its southern distribution limits in Africa.

Wetland is an important carbon pool, and the degradation of wetlands causes the loss of organic carbon and total nitrogen. This study aims to explore how wetland degradation succession affects soil organic carbon(SOC) and total nitrogen(TN) contents in alpine wetland. A field survey of 180 soilsampling profiles was conducted in an alpine wetland that has been classified into three degradation succession stages. The SOC and TN contents of soil layers from 0 to 200 cm depth were studied, including their distribution characteristics and the relationship between microtopography. The results showed that SOC and TN of different degradation succession gradients followed the ranked order of Non Degradation(ND) > Light Degradation(LD) > Heavy Degradation(HD). SWC was positively correlated with SOC and TN(p<0.05). As the degree of degradation succession worsened, SOC and TN became more sensitive to the SWC. Microtopography was closely related to the degree of wetland degradation succession, SWC, SOC and TN, especially in the topsoil(0-30 cm). This result showed that SWC was an important indicator of SOC/TN in alpine wetland. It is highly recommended to strengthen water injection into the wetland as a means of effective restoration to reverse alpine meadow back to marsh alpine wetland.

In seasonally frozen soil regions, freezingthawing action and hydrothermal effect have strong influence on physical and mechanical behavior of shallow soil. A field experiment on the Loess Plateau in Northwest China was carried out to analyze the freezing-thawing process and hydrothermal characteristics of shallow soil considering the climate influence. The results show that the maximum seasonal freezing depth under bare ground surface in this area is from 20 cm to 50 cm. The ground temperature shows a similar changing trend with air temperature, but it has lagged behind the air temperature, and the ground temperature amplitude exponentially decreases with the increase of soil depth. The seasonally frozen soil has experienced four typical stages: unfrozen period, alternate freezing period, freezing period and alternate thawing period. The freezing-thawing process is characterized by unidirectional freezing and bidirectional thawing. The water content of shallow soil is significantly affected by air temperature, evaporation and precipitation, and the soil water content shows a "low-high-low" changing trend with the increase of depth. The soil temperature and water content interact with each other, and are often coupled. The variation trend of soil moisture with time is consistent with the change trend of the ground temperature with time in each soil layer, and the degree of consistency is higher in the near surface soil than that in the lower layer. Also, the spatial-temporal characteristics of soil moisture and temperature is that the volumetric water content and ground temperature of near surface soil have strong variability, and the range value Ka and coefficient of variation Cv of soil water content and ground temperature in different seasons show a decreasing trend with the increase of depth.

The soil carbon pool which is the sum of soil organic carbon(SOC) and soil inorganic carbon(SIC) is the second largest active store of carbon after the oceans and it is an important component of the global carbon cycle. Hence, accurate estimation of SOC and SIC as important carbon reservoirs in terrestrial ecosystems using fast, inexpensive and non-destructive methods is crucial for planning different climate change policies. The aim of the current research was to examine the effectiveness of Vis-NIR(visible and near-infrared spectroscopy: 350-2500 nm) and MIR(mid-infrared spectroscopy: 4000-400 cm~(-1)) to characterize and estimate soil organic matter(SOM) and carbonates as main components of soil carbon stocks in Juneqan, Charmahal va Bakhtiari, Iran. To do so, a total of 548 soil samples from this area were collected(October 2015) and analyzed in laboratory(August 2017). In order to develop models capable of predicting SOM and carbonates content, seven spectral preprocessing methods comprising Absorbance(Abs), De-trending(Det), Continuum removal(CR), Savitzky-Golay derivatives(SGD), standard normal variate transformation(SNV), multiplicative scatter correction(MSC) and Normalization by range(NBR) were conducted along with five multivariate methods including Random Forest(RF), Partial Least-Squares Regression(PLSR), Artificial Neural Network(ANN), Support Vector Machine(SVM) and Gaussian Process Regression(GPR). The content of carbonates caused spectral reflectance intensity to augment on several ranges of spectrum and strong absorption feature at 2338 nm in the Vis-NIR and 714, 850, 870, 1796, 2150 and 2510 cm~(-1) in the MIR spectra range. SOM absorbed energy in several ranges, but also showed specific peaks in MIR. Both facts are associated with the structure of carbonates and SOM and its interaction with energy. The best combination of preprocessing and calibration models for carbonates quantification in Vis-NIR spectra was Det/PLSR(R~2= 0.74, RPD= 2.19, RMSE= 6.45). For SOM, it was Det/PLSR(R~2= 0.82, RPD= 2.41, RMSE= 0.75). The Det/RF(R~2= 0.87, RPD= 2.44, RMSE= 0.66) for the quantification of SOM and MSC/RF(R~2= 0.84, RPD= 2.84, RMSE= 5.50) for carbonates in MIR spectra range showed the greatest results. The stronger occurrence of spectral bands in MIR as well as the specificity of the absorption features indicated that this range produced better predictions. The obtained results highlighted the significant role of soil spectroscopy technique in predicting SOC and soil carbonates as key components of soil carbon stocks in the study area. Therefore, this technique can be used as a more cost-effective, time saving and nondestructive alternative to traditional methods of soil analysis.

Soil-rock mixtures containing macropore(SRMCM) is a kind of geological material with special mechanical properties. Located in the project area of Lenggu hydropower station on the Yalong River,Sichuan Province, China, there is an extremely unstable Mahe talus slide with a total volume of nearly160 million cubic meters, which is mainly composed of SRMCM. The study on the mechanical properties of SRMCM is of great significance for the engineering construction and safe operation. In this paper,laboratory tests and discrete element numerical tests based on three-dimensional scanning technology were conducted to study the influence of stone content,stone size, and the angle of the macropore structure on shear characteristics of SRMCM. The failure mechanism of SRMCM was discussed from a microscopic perspective. This work explains the internal mechanism of the influence of stone content,stone size, and the angle of the macropore structure on the strength of SRMCM through the microscopic level of stone rotation, force chain distribution, and crack propagation. As the macropore structure that intersects with the preset shear plane at a large angle could act as a skeleton-like support to resist the shear force, the fracture of the weak cemented surface of soil and stone in the macropore structure is an important cause of SRMCM destruction.

Endorheic basins(ENBs) are inland drainage basins allowing no outflow to oceans. These basins in the active mountain chains of the convergence zones are under the influence of compressional tectonic activity and climate condition. The Zagros Mountains of Iran is one of the youngest convergence zones in which continental-continental collision has occurred. In this paper we hypothesize the formation of ENBs among the Zagros range after the epeirogenic stage in the Late Paleogene-Early Neogene. Due to tectonic activity and Quaternary climatic conditions, the ENBs pass the transition stage to exorheic, and still, some tectonic depressions are not linked to the evolutionary process of exorheic drainage of Zagros. The geometry of the drainage network of Kul and Mond basins in Fars arch shows that 67% of their water gaps are located along the thrusts and transverse basement faults in the east and west of the Fars arch. Geometrically, the Kul and Mond basins form triangles with their sides matching with the edges of the Arabian Plate where the major inherited faults of Arabian plate controls the shape of the Zagros basin and a low strain zone along the Razak fault with lower salt tectonic activity, where the wind gaps are created. The ENBs are located in the rainshadow slopes, but the Kul and Mond basins are located in the upwind slopes of rain waves. This factor and the heavy rains of the basin lead to increase of the erosion potential, destruction of depressions, and floods and consequently, the funnel-shaped gaps have a significant impact on the flood flow.

In order to solve the problem of large deformation at the intersection of deep large section soft rock roadway, this paper takes the intersection of kilometer-deep roadway in the Wanfu Coal Mine as an engineering example and applies Negative Poisson's Ratio(NPR) steel anchor cable in roadway support for the first time. By combining numerical simulation indoor test, theoretical analysis and field test, the deformation mechanism of surrounding rock at the intersection of deep-buried roadway was analyzed, and the control strategy with micro NPR steel anchor cable as the core was put forward.Through numerical simulation, the numerical analysis model of roadway intersection with different intersection angles and excavation sequence was constructed, and the impact of two key variables of rake angle and excavation sequence on the stability of surrounding rock at roadway intersection was studied. The optimal dip angle is 90° and the optimal excavation sequence was determined as pump house-pump house passage-substation. The mechanical properties of the micro-NPR steel anchor cable were studied through the static tensile test in the laboratory. The results showed that the micro-NPR steel anchor cable showed high constant resistance,uniform tensile, no yield platform, and no obvious necking phenomenon during breaking. Through theoretical derivation, it was calculated that the vertical stress of roadway intersection is 45 MPa, and the bearing capacity of superposed arch composed of micro NPR steel anchor cable is 1257 kN, which is enough to guarantee the overall stability of intersection. Support application test and monitoring were carried out on site, and it was verified that the combined support strategy of short and long micro NPR steel anchor cable has a good control effect on large deformation of surrounding rock at intersection,which provides a new support material and support means for the safety and stabilization control of surrounding rock at intersection.

Salinization and desertification are closely related to water-salt migration caused by a temperature gradient. Based on the Darcy Law of unsaturated soils, the law of energy conservation and the law of mass conservation, the thermal-water-salt coupling mathematical model of unsaturated frozen saline soil was established. The model considered the latent heat of phase change, crystallization impedance, crystallization consumption and complete precipitation of solute crystallization in ice. In order to verify the rationality of the model, the unidirectional freezing test of unsaturated saline soil was carried out in an open system with no-pressure water supplement to obtain the spatial distribution of temperature, moisture and salt in the saline soil.Finally, numerical simulations are implemented with the assistance of COMSOL Multiphysics. Validation of the model is illustrated by comparisons between the simulation and experimental data. The results demonstrated that the temperature within saline soil changes with time and can be divided into three stages, namely quick freezing stage, transitional stage and stable stage. The water and salt contents in the freezing zone are layered, with peak values at the freezing front. The coupled model could reveal the heat-mass migration mechanism of unsaturated frozen saline soil and dynamically describe the freezing depth and the movement law of the freezing front, ice and salt crystal formation mechanism, and the change law of thermal conductivity and permeability coefficient.

This article presents a mathematical model for simulating the mechanical behaviour of lightning strikes and analysing the resulting damage to the soil. This article focuses on the electro-thermal effect and seepage caused by lightning strikes in particular. Then, a numerical model based on the conservation laws of momentum, mass and energy is developed for soil subjected to lightning strikes. Comparisons to field observations and theoretical calculations are used to demonstrate the efficacy and accuracy of numerical simulations. The findings demonstrate that lightning strikes can cause soils to experience both seepage force and heat stress. Under the calculative condition of this article: by increasing the intrinsic permeability of the soil, kp(≥10~(-10) m~2), the seepage force can be effectively reduced, hence reducing the risk of lightning strikes; improving the electrical conductivity of the soil β(≥10-1 S/m) and lowering its thermal expansion coefficient(≤10~(-6) K~(-1)) can greatly reduce the damage caused by lightning strikes to the soil. The preceding investigations demonstrate that the suggested model is capable of evaluating mechanical damage caused by lightning in the soil, and the findings contribute to a better understanding of soil mechanical response to lightning strikes

In the face of global warming and increasing impervious surfaces, quantifying the change of climate potential productivity(CPP) is of great significance for the food production planning.Targeting the Dongting Lake Basin, which is a key area for food production in China, this paper uses meteorological data, as well as Climate Change Initiative Land Cover, and Shuttle Radar Topography Mission digital elevation model to investigate the CPP and its changes from 2000 to 2020. The suitability of land for cultivation(SLC), and the land use/land cover change(LUCC) are also considered. The results showed that the CPP varied from 9,825 to 20,895 kg ha~(-1). Even though the newly added impervious surfaces indirectly resulted in the decrease of CPP by of 9.81×10~8 kg, overall, the CPP increased at an average rate of 83.7 kg ha~(-1) a~(-1). Global warming is the strongest driver behind CPP increase, and CPP has played an important role in the conversions between cultivated land and other land types. The structure of land types tends to be optimized against this challenge.

To quantify the impacts of native vegetation on the spatial and temporal variations in hydraulic properties of bank gully concentrated flows, a series of in situ flume experiments in the bank gully were performed at the Yuanmou Gully Erosion and Collapse Experimental Station in the dry-hot valley region of the Jinsha River, Southwest China. This experiment involved upstream catchment areas withone-and two-year native grass(Heteropogon contortus) and bare land drained to bare gully headcuts, i.e., Gullies 1, 2 and 3. In Gully 4, Heteropogon contortus and Agave sisalana were planted in the upstream catchment area and gully bed, respectively. Among these experiments, the sediment concentration in runoff in Gully 3 was the highest and that in Gully 2 was the lowest, clearly indicating that the sediment concentration in runoff obviously decreased and the deposition of sediment obviously increased as the vegetation cover increased. The concentrated flows were turbulent in response to the flow discharge. The concentrated flows in the gully zones with native grass and bare land were sub-and supercritical, respectively. The flow rate and shear stress in Gully 3 upstream catchment area were highest among the four upstream catchment areas, while the flow rate and shear stress in the gully bed of Gully 4 were lowest among the four gully beds, indicating that native grass notably decreased the bank gully flow rate and shear stress. The Darcy–Weisbach friction factor(resistance f) and flow energy consumption in the gully bed of Gully 4 were notably higher than those in the other three gully beds, clearly indicating that native grass increased the bank gully surface resistance and flow energy consumption. The Reynolds number(Re), flow rate, shear stress, resistance f, and flow energy consumption in the gully beds and upstream areas increased over time, while the sediment concentration in runoff and Froude number(Fr) decreased. Overall, increasing vegetation cover in upstream catchment areas and downstream gully beds of the bank gully is essential for gully erosion mitigation.

To study the damage mechanisms of anhydrite rock under freeze-thaw cycles, the physicalmechanical properties and the microcracking activities of anhydrite rock were investigated through mass variation, nuclear magnetic resonance, scanning electron microscope tests, and uniaxial compression combined with acoustic emission(AE) tests. Results show that with the increase of freeze-thaw processes,the mass, uniaxial compression strength, and elastic modulus of the anhydrite specimens decrease while the porosity and plasticity characteristics increase.For example, after 120 cycles, the uniaxial compression strength and elastic modulus decrease by 46.54% and 60.16%, and the porosity increase by 75%. Combined with the evolution trend of stressstrain curves and the detected events, three stages were labeled to investigate the AE characteristics in freeze-thaw weathered anhydrite rock. It is found that with the increase of freeze-thaw cycles, the proportions of AE counts in stage Ⅰ and stage Ⅱ show a decaying exponential trend. Contrarily, the proportion of AE counts in stage Ⅲ displays an exponential ascending trend. Meanwhile, as the freeze-thaw cycles increase, the low-frequency AE signals increase while the intermediate-frequency AE signals decrease. After 120 cycles, the proportion of low-frequency AE signals increases by 168.95%, and the proportion of intermediate-frequency AE signals reduces by 81.14%. It is concluded that the microtensile cracking events occupy a dominant position during the loading process. With the increase of freeze-thaw cycles, the b value of samples decreases.After 120 cycles, b value decreases by 27.2%, which means that the proportion of cracking events in rocks with small amplitude decreases. Finally, it is proposed that the freeze-thaw damage mechanism of anhydrite is also characterized by the water chemical softening effect.

Regeneration status of tree species along elevation gradient in temperate hill forest was not understood greatly. Present research examined the tree diversity and its regeneration patterns along an elevation gradient in temperate hill forest, central Nepal. Data were collected from 300 sample plots within vertical elevation bands of 10, ranging from 1365 to 2450 m asl. A random sampling method was used for data collection in three seasons, winter, premonsoon and post monsoon seasons. Diameter at breast height(DBH) was used to broadly categorize the plant individual into trees, saplings and seedlings. The tree species richness ranged from 12 to 25 with density of 350 to 1200 individuals per hectare. Species richness of tree and sapling showed statistically significant unimodal pattern, which peaked at midelevation. Elevation showed a strong and positive linear correlation with the seedling density(Deviance = 0.99, p < 0.001) and a significant hump-shaped relationship with sapling density(Deviance = 0.95, p < 0.001). Similarly, elevations showed a statistically significant negative hump-shaped relationship with all trees, saplings and seedling stages(Deviances = 0.89, 0.87 and 0.57). The highest values of the ShannonWiener index and the lowest value of the Simpson index were found at mid-elevation for all growth forms. Nearly 92% of tree species were found at regenerating stage; 49% in a good renewal regeneration status, 32% in fair renewal regeneration, and 11% at a poor regenerating condition. Nevertheless, 4% of tree species were reported as non-regenerating stages and 4% were newly introduced species. Hence, the regeneration status of the study area was considered fairly well since sapling(78.5%) > seedling(10.6%) ≤ mature(10.9%). Among tested environmental variables, elevation and annual mean rainfall were the most influential factors in the regeneration of tree species.

Currently, the application of the Yellow River silt in subgrade, especially in expressway subgrade, has not been widely promoted. The main reason is that the research on the mechanical characteristics of the Yellow River silt used for subgrade filling is extremely limited. In this study, the static shear test of the Yellow River silt under drained condition was carried out using Global Digital Systems(GDS) triaxial apparatus, and the effects of confining pressure, relative density and shear rate on the strength and deformation behavior of the Yellow River silt were investigated. The cohesive force of the Yellow River silt is low, and the friction angle is the main factor determining the shear strength. Friction angle at phase transformation state φ_(pt), friction angle at peak state φ_(ps), friction angle at critical state φ_(cs),were obtained via the observation on the evolution law of mobilized friction angle during the whole shearing process. The friction angles corresponding to three different characteristic states have the following magnitude relationship, namely φ_(ps)>φ_(cs)>φ_(pt). The strength parameters for low-grade subgrade and highgrade subgrade were chosen to be 29.33° and 33.75°.The critical state line(CSL), envelop of phase transformation(EOP), and envelop of dilatancy(EOD) for three different characteristic states were determined. The critical stress ratio M, the phase transformation stress ratio M_(pt) and the dilatancy stress ratio M_d of the Yellow River silt are 1.199, 1.235,1.152, respectively. These results provide a basis for the mechanical analysis of the Yellow River silt subgrades and the subsequent establishment of dynamic constitutive model of the Yellow River silt.

Stand structure dynamics are considered as major happenings in any forest as a response to environmental changes. However, this important topic is underrepresented in the treeline studies in the Nepal Himalayas. We aimed to investigate site-as well as species-specific changes in morphometric features(basal diameter, crown cover, density, and height) along the elevational gradient across treeline ecotones in response to recent environmental changes. The stand structure characteristics of Abies spectabilis, Pinus wallichiana, and Betula utilis across the treeline ecotone of three study sites in Eastern(Barun), Central(Manang), and Western(Dhorpatan) Nepal were analyzed to elucidate structural heterogeneities. Altogether, eight transects(20 m ×(60–250 m)) across the treeline ecotone were established. Trees of all life forms, trees(> 2 m), saplings(0.5–2 m), and seedlings(< 0.5 m), within each transect were enumerated and sampled for the morphometric features and age. Site-specific and species-specific stand structure dynamics were found. The rate of basal area increment was higher in Barun, but the Manang treeline, despite profound regeneration in recent years, had a low annual basal area increment. Moreover, the altitudinal distribution of age and morphometry were not consistent among those ecotones. Furthermore, intra-specific competition was not significant. The site-specific stand structure dynamics explain why treelines do not respond uniformly to increasing temperature. It invokes, in further studies, the incorporation of the tree's morphometric adaptation traits, phenotypic plasticity, and interactions between species genotype and the environment.

An understanding of how different land covers affect soil erosion caused by rainfall is necessary in mountainous areas. The land cover usually plays an important role in controlling landslide hazards associated with these terrains. This paper presents the results of a field experiment where several types of land covers were placed on a full-scale embankment as erosion control. An 8 m wide, 21 m long, and 3 m high embankment with a 45° side-slope was built with lateric soil. The soil was compacted under a relative compaction of 70% to simulate a natural soil slope. Two sides of the embankment were divided into six land cover areas, with three different areas of bare soil, and one each of a geosynthetic cementitious composite mat(GCCM), vetiver grass,and a combination of GCCM and vegetation. Soil erosion and moisture levels were monitored for each land cover area during six natural rainfall events encountered over the experimental period. Field results were compared with a numerical simulation and empirical soil loss equation. The results revealed that the GCCM gave the best erosion control immediately after installation, but vetiver grass also exhibited good erosion control six months postconstruction.

Residual soils are weathering products of rocks that are commonly found under unsaturated conditions. The properties of residual soils are a function of the degree of weathering. A series of index properties, engineering properties and geophysics survey examinations were performed on residual soils from two major geological formations in Iran. In the present research, the index properties of residual soils in the south of Mashhad city in Iran are investigated.Natural and artificial trenches were analyzed for evaluating the weathering profiles and collecting soil samples. Disturbed and undisturbed samples were obtained from each of the soil profile horizons resulting from weathering of different parent rocks.Subsequently, physical properties and mechanical properties of the soil samples were determined in accordance with ASTM standards. Also, the mineralogical composition, chemistry, and texture of the soil were evaluated in 51 profiles. The field observations showed the difference in the weathering profile of residual soils deposited on various rocks(igneous, sedimentary, and metamorphic). These profiles mainly consisted of two horizons includingresidual soil on top and saprolite at the bottom. The results of laboratory tests and geotechnical data showed that the properties of residual soil samples change by depth. Moreover, depending on the type of origin rock, the properties are different in various types of residual soils. In most of the samples, the moisture content of soil horizons was also increased by depth. Based on the unified soil classification(USCS), the soils of the upper horizons appeared to be classified as ML(Lean silt) and CL(Lean clay) while the soils of the lower horizons(saprolite zone) fall in SC(clayey sand), SM(silty sand), and SW(wellgraded sand) classes. Moreover, the results demonstrated that the particle size of the soil was increased by depth. Comparison of results of the geotechnical tests showed that properties of residual soils are changed by variations of depth, weathering level, and type of parent rock. Considering the concentration of the number of lines and the concentration of the points of intersection, the length and dimension fractal of lineaments in the southeastern part of the study area, it is evident that this zone possesses weathering severity and soil thickness. Fieldwork data from this zone have also verified the severity of weathering conditions. The analysis of lineaments trends in different parts of the study area indicated that the lineaments with the NW-SE trend have a strong effect on weathering development. The weathering depth depends on the orientation of bedding joints with respect to the slope in the study area. Slope inclination and soil thickness are controlled by weathering and erosion processes.

Deep-seated rock fractures(referred to as DSRF hereafter) in valley slopes are uncommon geological phenomena that challenge our previous understanding of slope unloading processes. These fractures weaken the strength and integrity of the rock mass, potentially forming unstable block boundaries with significant volume, thereby affecting the stability of slopes, chambers, and dam abutments.DSRF has emerged as a critical environmental and engineering geological issue that hinders large-scale projects in deep canyon areas. Despite the attention and practical treatment given to DSRF in engineering practice, theoretical research on this topic still lags behind the demands of engineering applications. To garner widespread attention and promote the resolution of DSRF-related problems, this review aims to redefine DSRF through comprehensive data collection and analysis, engineering geological analogies, and field investigations, and provide a summary and analysis of the research progress on DSRF, along with future research directions. The study defines DSRF as the intermittent tension cracks or relaxation zones within a slightly weathered or fresh, and intact or relatively intact rock mass distributed below the surface unloading zones of a deep canyon slope, and should be distinguished from "loose rock mass" and "deep-seated gravitational slope deformations". The article provides an overview of the development and distribution, rupture characteristics, and genesis mechanism of DSRF. It proposes that DSRF is formed based on the fluvial deviation-undercutting evolution mode, wherein the energy accumulated in the rock mass is violently released when the river further down cuts the slope after the rock mass has undergone cyclical loadingunloading. However, further research is necessary to establish a comprehensive database for DSRF, refine exploration techniques, understand evolutionary processes, develop engineering evaluation methods,and predict the distribution of DSRF.

The multi-model assessment of glaciohydrological regimes can enhance our understanding of glacier response to climate change. This improved knowledge can uplift our computing abilities to estimate the contributing components of the river discharge. This study examined and compared the hydrological responses in the glacier-dominated Shigar River basin(SRB) under various climatic scenarios using a semi-distributed Modified Positive Degree Day Model(MPDDM) and a distributed Glacio-hydrological Degree-day Model(GDM). Both glacio-hydrological models were calibrated and validated against the observed hydro-meteorological data from 1988-1992 and 1993-1997. Temperature and precipitation data from Shigar and Skardu meteorological stations were used along with field estimated degree-day factor, temperature, and precipitation gradients. The results from both models indicate that the snow and ice melt are vital contributors to sustain river flow in the catchment. However, MPDDM estimated 68% of rain and baseflow contribution to annual river runoff despite low precipitation during the summer monsoon, while GDM estimated 14% rain and baseflow contribution. Likewise, MPDDM calculated 32%, and GDM generated 86% of the annual river runoff from snow and ice melt. MPDDM simulated river discharge with 0.86 and 0.78 NSE for calibration and validation, respectively. Similarly, GDM simulated river discharge with improved accuracy of 0.87 for calibration and 0.84 NSE for the validation period. The snow and ice melt is significant in sustaining river flow in the SRB, and substantial changes in melt characteristics of snow and ice are expected to have severe consequences on seasonal water availability. Based on the sensitivity analysis, both models' outputs are highly sensitive to the variation in temperature. Furthermore, compared to MPDDM, GDM simulated considerable variation in the river discharge in climate scenarios, RCP4.5 and 8.5, mainly due to the higher sensitivity of GDM model outputs to temperature change. The integration of an updated melt module and two reservoir baseflow module in GDM is anticipated to advance the representation of hydrological components, unlike one reservoir baseflow module used separately in MPDDM. The restructured melt and baseflow modules in GDM have fundamentally enriched our perception of glacio-hydrological dynamics in the catchment.

Kathmandu Kyirong Highway(KKH) is one of the most strategic Sino-Nepal highways. Lowcost mitigation measures are common in Nepalese highways, however, they are not even applied sufficiently to control slope instability since the major part of this highway falls still under the category of feeder road, and thus less resources are made available for its maintenance. It is subjected to frequent landslide events in an annual basis, especially during monsoon season. The Gorkha earthquake, 2015 further mobilized substantial hillslope materials and damaged the road in several locations. The aim of this research is to access the dynamic landslide susceptibility considering pre, co and post seismic mass failures. We mapped 5,349 multi-temporal landslides of 15 years(2004-2018), using high resolution satellite images and field data, and grouped them in aforementioned three time periods. Landslide susceptibility was assessed with the application of 'certainty factor'(CF). Seventy percent landslides were used for susceptibility modelling and 30% for validation. The obtained results were evaluated by plotting 'receiver operative characteristic'(ROC) curves. The CF performed well with the 'area under curve'(AUC) 0.820, 0.875 and 0.817 for the success rates, and 0.809, 0.890 and 0.760 for the prediction rates for respective pre, co and post seismic landslide susceptibility. The accuracy for seismic landslide susceptibility was better than pre and post-quake ones. It might be because of the differences on completeness of the landslide inventory, which might have been possibly done better for the single event based co-seismic landslide mapping in comparison with multitemporal inventories in pre and post-quake situations. The results obtained in this study provide insights on dynamic spatial probability of landslide occurrences in the changing condition of triggering agents. This work can be a good contribution to the methodologies for the evaluation of the dynamic landslide hazard and risk, which will further help to design the efficient mitigation measures along the mountain highways.

The highest volcano in Mexico, at the same time the third largest mountain in North America(Citlaltépetl, 5610 m a.s.l.), is home to the largest glacier in the country. Because of the extinction of the Popocatépetl glacier(5500 m a.s.l.) caused by eruptive activity, and the almost disappearance of the Iztaccíhuatl glaciers(5220 m a.s.l.) due to the lower elevation of the mountain, the Glaciar Norte of Citlatépetl has been the only glacier that has shown a certain degree of stability as a response to the altitude in which it is located. However, as occurs in almost all glaciers on the planet, the retreat of its glacier terminus has been continuous. Furthermore, during the last years the thickness of its upper part began to decrease rapidly until its bedrock was exposed for the first time in 2019. Due to its ecosystem importance and because it is the main glacier in Mexico, as well as the only one in the world located at latitude 19°N, in this work its current dimensions are updated, as well as the local climatology that governs the current state of the glacier is pointed out. The study was based on the analysis of high-resolution Sentinel-2 optical images, as well as through Sentinel-1 SAR images,with the support of climatological information from the study area. Therefore, the outcropping of the bedrock in the accumulation zone and the consequent horizontal retreat of the upper part of the glacier are documented; at the same time, the decrease in the thickness of the ice along it is noted. The rocky outcrop in the accumulation zone suggests that the flow dynamics of the ice towards the ablation zone will be considerably less, accelerating the retreat of the glacier terminus. Finally, the ascent of the glacial front to 5102 m a.s.l. and the modelled altitude of the equilibrium line to 5276 m a.s.l. are reported as a warning signal in terms of snow catchment and mass balance; likewise, the decrease of 23% of its surface is also indicated regarding the surface reduction monitoring that has been done until 2017. These findings may indicate that the future of this glacier is related to its possible extinction sooner than previously thought, with severe environmental consequences, especially in terms of the provision of drinking water for thousands of inhabitants of the slopes of the volcano. This research is expected to help reflect on the impacts of current climate variability and at the same time serve as a reference for the tropical glaciers on the planet.

In areas with seasonal freezing, when the tunnel lining concrete is saturated with water infiltrating the interior, the lining and the surrounding rocks will simultaneously freeze.However, the current calculation of the frost heaving force fails to consider the synchronous damage to the lining and surrounding rocks under freeze–thaw cycles. Therefore, as per the elastic calculation model of the frost heaving force and model of steady-state heat transfer of circular tunnels, this study introduces the frost heaving rate of lining and surrounding rocks.First, the analytical solution of frost heaving force is obtained for simultaneous frost heaving of lining and surrounding rocks under any steady-state temperature field. Then, based on the fracture theory and meso-damage mechanics, the damage variables of lining and surrounding rocks under freeze–thaw cycles are extracted, representing their elastic modulus and porosity. Finally, the formula of frost heaving force for synchronous damage to the lining and surrounding rocks at any steady-state temperature field is obtained. The calculation results demonstrate that the lower the temperature inside the lining, the greater the frost heaving force. With the increasing number of freeze–thaw cycles, frost heaving force tends to gradually increase initially,reaching a peak value at 85 freeze–thaw cycles,decreasing to 80% of the peak value at 140 cycles before reaching a constant value. The lining participates in frost heaving, increasing the frost heaving force. The initial increase rate of frost heaving force is 15.7%. Changing the fitting coefficients s1 and s2 of the lining and surrounding rocks can effectively control the magnitude of the frost heaving force in the tunnels.

Inherited tectonic structures, ongoing tectonic deformation, and variations in relative rock uplift rates play an important role in conditioning the processes of relief development. Their influence among other factors, such as climate and lithology, can be quantified using landscape analysis, and geomorphometric indices, in particular. The usage of landscape analysis in recent years is increasing systematically due to the constant improvement of the digital elevation models and GIS software that significantly facilitate this approach. In this study, we aim to recognize the influence of tectonic structures and processes on relief development in the low mountains with moderate relief of the So?a River catchment in the Western Outer Carpathians. To this end, we calculated geomorphometric indices(river longitudinal profile, stream-length gradient index, minimum bulk erosion, relief ratio, circulatory ratio, elongation ratio, and hypsometric integral) for the So?a River and its 47 sub-catchments using a 25-m spatial resolution Digital Terrain Elevation Data Level 2. Additionally, we identified lineaments and knickpoints and correlated the computed results with local and regional fault networks, variations in lithology, and climate fluctuations. Obtained results indicate a significant impact of inherited tectonicstructures on the relief development of the So?a River catchment, i.e., directions of principal ridges and valleys follow the orientation of main folds and faults recorded in this area. Anomalously high values of minimum bulk erosion, river gradient, and streamlength gradient index allowed us to define two areas with higher relative uplift rates: 1) the So?a Gorge and 2) the Beskid ?ywiecki Mts. Polish Outer Carpathians are generally considered as an area of low strain rate and low seismic activity. However, the possibility of neotectonic processes should be considered in geohazard estimations. Observed bends in the direction of river valleys that do not correspond with changes in lithology could be related to active strikeslip faults. These are probably the reactivated basement structures, copied in the thin-skinned nappe cover, as a result of the accommodation of the Mur-?ilina Fault Zone resulting from the tectonic push of the Alcapa(Alpine-Carpathian-Pannonian) microplate against the European plate. Thus, the role of recent tectonic activity in relief development of the So?a River catchment even though appears to be subsidiary at the most, should not be excluded.

At 12:52 pm on September 5, 2022, an MS 6.8 earthquake occurred in Luding County, Sichuan Province, China. Based on high-resolution aerial photographs and satellite imageries obtained after the earthquake, as well as field investigation, a total of 8685 earthquake-triggered landslides(EQTLs) were interpreted. The landslides covered an area of 30.7km2, with a source area of 9.4 km2. These EQTLs were mainly distributed in areas with a seismic intensity of VIII and IX. Most of the landslides were small and medium in size, and their types included landslide,rockfall, and rock slump. Characteristic landslide distributions were found, EQTLs were distributed along the Xianshuihe fault, landslide area decreased gradually with an increased distance to the fault;EQTLs were distributed along the Daduhe River and roads; besides, landslide distribution was associated with ground deformation caused by the earthquake.EQTLs' characteristics indicated that, a large number of EQTLs were located near the foot of the slope; the full area of EQTLs and their source area followed a power function. This study concluded that Luding EQTLs were greater in number and area but relatively smaller in terms of affected area. Investigations on geo-hazards post-earthquake and risk assessment were proposed in the earthquake-stricken area to support the rehabilitation and reconstruction.

The Thar Desert, Sindh, Pakistan is characterized by low productivity. Besides, economy is based on agriculture, livestock and mining,nevertheless, livestock graze freely on public and private land. The aim of this research was to determine biomass production and to evaluate the effects of continuous and seasonal grazing on protected and unprotected plots. A 45 ha protected rangeland area of Hurrabad in the Umerkot Thar desert was selected and divided into three blocks of 15 ha each. Blocks of the same size were also established in unprotected area. The data for vegetation biomass,canopy cover, forage nutrients and weight gain of animals in two seasons(spring and summer) was collected from both protected and unprotected sites.The results showed that biomass significantly increased in summer in both sites. However, the biomass values in protected sites were significantly higher. Similarly, the vegetation cover also seemed to increase in summer in both protected(90.7% ± 0.29%)and unprotected sites(39.2% ± 0.09%). The foliar concentrations of all nutrients varied significantly with season. The average final live-weight gain for does on the protected grazing sites during the 42-day period in spring and the 96 days after the monsoon was almost double that of does grazing on the unprotected site during 2016 and 2017(P < 0.05).The study concludes that the protection of grazing lands during certain periods can lead to better production of vegetation and livestock and improve range conditions.

Tunnel-type anchorages(TTAs) installed in human gathering areas are characterized by a shallow burial depth, and in many instances, they utilize soft rock as the bearing stratum. However, the stability control measures and the principle of shallow TTAs in soft rock have not been fully studied. Hence, a structure suitable for improving the stability of shallow TTAs in soft rock strata, named the anti-pull tie(APT),was added to the floor of the back face. Physical tests and numerical models were established to study the influence of the APT on the load transfer of TTAs, the mechanical response of the surrounding rock, the stress distribution of the interface, and the failure model. The mechanical characteristics of APTs were also studied. The results show that the ultimate bearing capacity of TTAs with an APT is increased by approximately 11.8%, as compared to the TTAs without an APT. Also, the bearing capacity of TTAs increases approximately linearly with increasing height, width,length, and quantity of APTs, and decreases approximately linearly with increasing distance from the back face and slope angle of the tie slope. The normal squeezing between the tie slope and the surrounding rock increases the shear resistance of the interface and expands the range of the surrounding rock participating in bearing sharing. Both tension and compression zones exist in the APT during loading.The tension zone extends from the tie toe to the tie bottom along the tie slope. The range of the tie body tension zone constantly expands to the deep part of the APT with an increasing load. The peak tensile stress value is located at the tie toe. The distribution of compressive stress in the tie body is the largest at the tie top, followed by the tie slope, and then the tie bottom.

Soil moisture is a limiting factor of ecosystem development in the semi-arid Loess Plateau. Characterizing the soil moisture response to its dominant controlling factors, such as land use and topography, and quantifying the soil-water carrying capacity for revegetation is of great significance for vegetation restoration in this region. In this study, soil moisture was monitored to a depth of 2 m in three land use types(native grassland, introduced grassland,and forestland), two landforms(hillslope and gully),and two slope aspects(sunny and shady) in the Nanxiaohegou watershed of the Loess Plateau,Northwest China. The MIKE SHE model was then applied to simulate the soil moisture dynamics under different conditions and determine the optimal plant coverage. Results showed that the average soil moisture was higher in native grassland than in introduced grassland and Platycladus orientalis forestland for a given topographic condition; however,a high soil moisture content was found in Robinia pseudoacacia forestland, with a value that was even higher than the native grassland of a sunny slope. The divergent results in the two forestlands were likely attributed to the differences in plant coverage. Gully regions and shady slopes usually had higher soil moisture, while lower soil moisture was usually distributed on the hillslope and sunny slope.Furthermore, the mean absolute relative error and Nash-Sutcliffe efficiency coefficient of the MIKE SHE model ranged between 2.8%–7.8% and 0.550–0.902,respectively, indicating that the model could effectively simulate the soil moisture dynamics. The optimal plant coverage was thus determined for hillslope P. orientalis by the model, corresponding to a leaf area index(LAI) value of 1.92. Therefore, for sustainable revegetation on the Loess Plateau,selecting suitable land use types(natural vegetation),controlling the planting density/LAI, and selecting proper planting locations(gully and shady slope regions) should be considered by local policy makers to avoid the over-consumption of soil water resources.

Although the construction of underground dams is one of the best methods to conserve water resources in arid and semi-arid regions, applying efficient methods for the selection of suitable sites for subsurface dam construction remains a challenge.Due to the costly and time-consuming methods of site selection for underground dam construction, this study aimed to present a new method using geographic information systems techniques and decision-making processes. The exclusionary criteria including fault, slope, hypsometry, land use, soil,stream, geology, and chemical properties of groundwater were selected for site selection of dam construction and inappropriate regions were omitted by integration and scoring layers in ArcGIS based on the Boolean logic. Finally, appropriate sites were prioritized using the Multi-Attribute Utility Theory.According to the results of the utility coefficient, seven sites were selected as the region for underground dam construction based on all criteria and experts' opinions. The site of Nazarabad dam was the best location for underground dam construction with a utility coefficient of 0.7137 followed by sites of Akhavan with a utility coefficient of 0.4633 and Mirshamsi with a utility coefficient of 0.4083. This study proposed a new approach for the construction of the subsurface dam at the proper site and help managers and decision-makers achieve sustainable water resources with limited facilities and capital and avoid wasting national capital.