In this paper a three-dimensional agro-hydrological model for shallow landslides' prediction is presented. The model is an extension of the CRITERIA-3D free-source model for crop development and soil hydrology, developed by the Hydrometeorological service of the Regional Agency for Environmental prevention and Energy of EmiliaRomagna region (Arpae-simc). The soil-water balance is computed through the coupling of surface and subsurface flows in multi-layered soils over areas topographically characterized by Digital Elevation Model (DEM). The rainfall infiltration process is simulated through a three-dimensional version of Richards' equation. Surface runoff, lateral drainage, capillarity rise, soil evaporation and plant transpiration contribute to the computation of the soil hydrology on an hourly basis. The model accepts meteorological hourly records as input data and outputs can be obtained for any time step at any selected depth of the soil profile. Among the outputs, volumetric water content, soil-water potential and the factor of safety of the slope can be selected. The validation of the proposed model has been carried out considering a test slope in Montue` (northern Italy), where a shallow landslide occurred in 2014 a few meters away from a meteorological and soil moisture measurement station. The paper shows the accuracy of the model in predicting the landslide occurrence in response to rainfall both in time and space. Although there are some model limitations, at the slope scale the model results are highly accurate with respect to field data even when the spatial resolution of the Digital Elevation Model is reduced.

Terrestrial ecosystems, account for approximately 31% of the global land area and play a significant role in the biogeochemical cycling of toxic elements. Previous studies have explored the spatial patterns, effects, and drivers of toxic elements along urban gradients, agricultural lands, grasslands, and mining sites. However, the elevational patterns of toxic elements in montane ecosystems and the underlying drivers remain largely unknown. Atmospheric deposition is a crucial pathway through which toxic elements accumulate along terrestrial elevational gradients. The accumulation of toxic elements exhibited seasonal variability along elevational gradients, with higher deposition occurring in summer and winter. Approximately 46.77% of toxic elements (e.g. Hg) exhibited increasing trends with elevation, while 22.58% demonstrated decreasing patterns (Ba, Co). Furthermore, 8.06% displayed hump-shaped distributions (Ag), and 22.58% showed no distinct patterns (As and Zn). The accumulation of these elements is influenced by several key factors, including atmospheric deposition (26.56%), anthropogenic activities (14.11%), and precipitation (10.37%) primarily via wet deposition of atmospheric pollutants. The accumulation of toxic elements threatens terrestrial biodiversity by disrupting food chains, altering community structures, and causing individual mortality. These disruptions also pose risks to human health through contaminated food sources and food webs, potentially leading to health issues like cancer, organ damage, and reproductive challenges. This review offers key insights into the factors affecting the accumulation and distribution of toxic elements along elevation gradients. It also lays the groundwork for further study on how toxic elements impact ecosystem functions, which is crucial for protecting biodiversity under climate change.

Landslides can cause severe damage to property and human life. Identifying their locations and characteristics is crucial for emergency rescue and disaster risk assessment. However, existing methods need help in accurately detecting landslides because of their diverse characteristics and scales, as well as the differences in spectral features and spatial heterogeneity of remote sensing images. To overcome these challenges, a multiscale feature fusion landslide-detection network (MFLD-Net) is proposed. This network utilizes reflectance difference images from pre- and post-landslide Sentinel-2A images, along with digital elevation model (DEM) data. Moreover, a multichannel differential landslide dataset was constructed through spectral analysis of Sentinel-2A images, which facilitates network training and enables differentiation between landslides and other objects with similar spectral features, such as bare soil and buildings. The proposed MFLD-Net was tested in Shuzheng Valley and Detuo town in Sichuan, China, where earthquakes have occurred. The experimental results revealed that compared with advanced deep learning models, MFLD-Net has promising landslide detection performance. This study provides suggestions for selecting optimal deep learning methods and spectral band combinations for landslide detection and offers a publicly available landslide dataset for further research.

Key messageRoot morphology and tensile strength were affected by elevation, with changes in the former showing adaptation to the environment, and changes in the latter mainly influenced by root chemical composition.AbstractPlant roots have absorption and anchorage functions and play important roles in plant growth and slope stability. Root morphology and mechanics are closely related to root function and are influenced by various factors. However, the impact of elevation, which encompasses a range of environmental changes, has not been fully studied. This study aimed to investigate the responses of root morphology and root mechanics to environmental changes associated with elevation and to explore the possible effects of these responses on root reinforcement. We measured the morphological properties (length, diameter, and number), tensile strength, and chemical composition (cellulose, hemicellulose, and lignin contents) of the taproots and first- and second-order roots of Lespedeza bicolor Turcz. grown at three different elevations (986, 1839, and 2716 m). The lengths of both taproots and lateral roots decreased, while the diameter of lateral roots increased with increasing elevation. Additionally, there was a significant increase in root tensile strength as elevation increased, accompanied by an increase in cellulose content and a decrease in lignin content. Root tensile strength correlated positively with cellulose content and negatively with lignin content. The morphological and mechanical properties of L. bicolor roots are significantly influenced by elevation. Roots exhibit adaptive strategies in response to environmental factors such as hydrothermal conditions and soil nutrient availability. Cellulose and lignin have a significant impact on the biomechanical properties of roots. Regarding soil reinforcement, roots at lower elevations exhibit a more advantageous morphology. Conversely, roots at higher elevations possess greater biomass and tensile strength, making them more resistant to soil erosion under extreme environmental conditions.

Plant-parasitic nematodes (PPNs) are significant agricultural pests that cause substantial crop losses globally. This study investigated the abundance and distribution of PPNs concerning elevation in rice fields in Malang District, East Java, Indonesia. Nematodes were sampled across elevation gradients between 0 to over 1000 meters above sea level (masl). Pratylenchus, Aphelenchoides, and Longidorus, were found in the soil and rice roots in Malang District. Pratylenchus dominated the relative abundance of PPNs in the soil at 0-400 masl, whereas Longidorus dominated at 600 to > 1000 masl. In rice root samples, Pratylenchus sp. also dominated at 0-400 masl and Longidorus was dominated at 800-100 masl. The population density of Pratylenchus negatively correlated to elevation, pH, soil organic matter, and carbon organic. However, soil temperature positively correlated with the population density of Pratylenchus. Elevation and pH showed a negative influence on the population density of Aphelenchoides, whereas soil temperature showed a positive influence on the population density of Aphelenchoides. Soil temperature negatively correlated to the population density of Longidorus, whereas elevation and soil humidity positively influenced the population density of Longidorus. However, the population density of Longidorus increased with higher elevation and soil humidity. Understanding the specific relationships between PPN populations and environmental factors is essential for developing effective pest management strategies. Targeted approaches that consider these ecological dynamics can help mitigate crop damage and enhance rice production in varying environmental conditions, especially in the Java region.

A scenario-based approach was used to test air and ground response to warming with and without changes to inverted surface lapse rates in four Yukon valleys. Generally, climate warming coupled with weakening of temperature inversions resulted in the greatest increase in air temperature at low elevations. However, ground temperatures at high elevations showed the greatest response to warming and variability between scenarios due to increased connectivity between air and ground. Low elevations showed less of a response to warming and permafrost was largely preserved in these locations. Local models also predicted higher permafrost occurrence compared to a regional permafrost probability model, due to the inclusion of differential surface and thermal offsets. Results show that the spatial warming patterns in these mountains may not follow those predicted in other mountain environments following elevation-dependent warming (EDW). As a result, the concept of EDW should be expanded to become more inclusive of a wider range of possible spatial warming distributions. The purpose of this paper is not to provide exact estimations of warming, but rather to provide hypothetical spatial warming patterns, based on logical predictions of changes to temperature inversion strength, which may not directly follow the distribution projected through EDW.

Erosive processes occur naturally and are essential for soil formation. However, they have been accelerated by anthropogenic actions, contributing to social, environmental, and economic damages. The aim of this study was to develop a methodology for the identification and quantification of soil loss using digital elevation models obtained through imagery from unmanned aerial vehicles (UAVs). In the three selected study areas in Te & oacute;filo Otoni - MG, the generated models were compared before and after precipitation events. The annual erosivity factor can be classified as very low, indicating regional characteristics of low erosive potential. This work proposed different equations for the use of Digital Elevation Models as a data source for the identification and quantification of soil loss through water erosion. The results obtained indicate that flights conducted up to 70 meters contribute to mapping quality and highlight the need for further studies to calibrate the methodology for quantifying soil loss and making it replicable in different situations.

Three-dimensional slope stability study is preferable to 2D stability assessments since all slopes are three-dimensional. Based on 3D extensions of the ordinary slice method and simplified Bishop's method, this study presents 3D slope stability analysis results for homogenous and heterogeneous soil slopes. The geometry of the slope is built with the help of the Digital Elevation Modelling (DEM) technique. Both the ordinary column method (OCM) and simplified Bishop's method (SBM) in 3D satisfy the moment equilibrium of the failure mass. The obtained FS values for all three problems match the published results closely. The effects of pore water pressure applications and seismic loadings are further investigated by considering different combinations. The pore pressure ratio (ru) and horizontal seismic coefficient (keq), with values ranging from 0.25 to 0.50 and 0.05 to 0.10, respectively, have been considered in the present analysis. The detailed variations of normal and shear forces acting on the base of the 3D columns, as well as the variations of other important parameters such as true dip angle and apparent dip angles along the longitudinal and lateral direction of the failure surface, are shown to highlight the mechanisms of generation of internal forces inside the failure mass, both along longitudinal and lateral directions of the slope. The plots of normal and shear forces along the longitudinal direction of the slope follow a symmetric distribution. In contrast, these plots along the lateral direction of the slope follow an asymmetric profile. It is further seen that when pore pressure and earthquake forces are considered, the normal forces increase, and the mobilised shear forces decrease along both longitudinal and lateral directions of the 3D slope.

Elevation plays a crucial role in modulating the spatiotemporal distributions of climatic variables in mountainous regions, which affects water and energy balances, among which reference evapotranspiration (ET0) is a key hydrological indicator. However, the response of ET0 to climate change with elevation continues to be poorly understood, especially in the Tibetan Plateau (TP) which has elevation variations of more than 4,000m. The spatiotemporal variations of ET0 with elevation were investigated using long-term (1960-2017) meteorological observations from 82 stations on the TP. The results suggest that the average annual ET0 showed an insignificant increasing trend. A significant negative correlation between ET0 and elevation was found (p<.01). The positive trends of ET0 decreased with elevation, whereas the negative trends of ET0 increased significantly with elevation (p<.05). The magnitude of trends of ET0 becomes smaller at higher-elevation stations. Sensitivity analysis indicated that ET0 was most sensitive to shortwave radiation (R-s). Moreover, the sensitivities of temperature (T) and wind speed (U) significantly decreased with elevation, whereas those of R-s and vapour pressure deficit (VPD) increased slightly with elevation. The contribution and path analyse indicated that increasing VPD was the dominant contributor to the increase in ET0. The effect of elevation on ET0 variation mainly depended on the tradeoff between the contributions of U and VPD. U was the largest contributing factor for the change in ET0 below 2,500m, whereas VPD was the primary contributor to the increase in ET0 above 2,500m. This study provides insights into the response of ET0 to climate change with elevation on the TP, which is of great significance to hydrometeorological processes in high-altitude regions.

Urban cover-collapse sinkholes pose a significant global challenge due to their destructive impacts. Previous studies have identified groundwater fluctuations, subsurface soil conditions, pipeline leakage, precipitation, and subterranean construction activities as key contributors to these phenomena. However, unique geological settings across different urban environments lead to variations in the primary factors influencing sinkhole formation. This study focuses on Shanghai, a city notable for its extensive urbanization and rich historical context, to explore the dynamics of sinkholes within urbanized areas worldwide. We employ spatial analysis and statistical methods to examine data on sinkholes recorded in the past two decades in Shanghai, correlating these events with the city's shallow sand layer, ground elevation, and proximity to surface water. Our goal is to identify the dominant factors governing sinkhole occurrence in Shanghai and to lay the groundwork for their effective scientific management and prevention. Key findings indicate that most sinkholes in the area are associated with a thin shallow sand layer, low to moderate ground elevations, and the absence of nearby rivers. Additionally, many sinkholes correlate with subterranean voids within the confined aquifer beneath the cohesive soil layer. The lack of historical river channels, obscured by urban development, also indirectly contributes to sinkhole formation. We recommend enhancing urban river management and drainage systems to mitigate potential damage from water accumulation.