The study of the damage effects resulting from the explosions of cylindrical charges holds significant importance in both military and civilian fields. In contrast to spherical charges, the explosive characteristics of the cylindrical charge exhibited spatial irregularities. To comprehensively quantify the influences of borehole diameter and buried depth on the damage effects, including the crater size and stress wave, experimental and numerical investigations on explosions induced by cylindrical charge are carried out in this paper. Firstly, a set of tests is conducted to provide fundamental data. Then, based on the meshfree method of Smoothed Particle Galerkin (SPG) and the K&C model, the variations in crater dimensions and the peak stress are fully simulated with a range of borehole diameters and buried depths. Finally, the influence of borehole and buried depth on the coupling factor is discussed. Both the buried depth and the borehole diameter impact the utilization of blast energy enormously. Furthermore, materials with distinct impedance values exert an influence on the distribution of the stress wave. Following the dimensional analysis, several empirical formulae expressing the crater size and peak stress are established, all of which can predict explosion damage rapidly and accurately.

A heavy armed conflict erupted in Tigray region of Ethiopia in 2020, and the crisis continued up to 2022. This study investigates the impacts of this crisis on the status of natural resources, and Soil and Water Conservation (SWC) efforts. We collected primary data through field observations, measurements, interviews and group discussions during the wartime. We also reviewed published articles and official archives to complement the primary data, which were often challenging to obtain due to the war. We found that vegetated landscapes were damaged by artillery fire and bombings. The average depth of the surveyed bomb craters along the asphalts was 1.15 +/- 0.47 m (n 1/4 16), whereas the average surface diameter of the craters and their rim was 2.66 +/- 0.67 m. In addition, the construction of numerous military trenches along croplands and hillsides exposed the soil particles into erosion and water pollution. The conflict also halted SWC efforts on various land uses, which were carried out annually during peacetime. For instance, 20,591 km/year of stone bunds were not constructed per year due to the crisis. Moreover, terraces and stone bunds were demolished to construct temporary ground fortifications. Indirectly, the critical energy crisis further increased pressure on forests. In this context, the poor farmers shift their livelihood strategies from the long-term sustainability to immediate economic recovery during the critical time. To conclude, the pathways of the warfare undermined the status of natural resources, and the ongoing decades of re-greening programs. Therefore, our ground-based findings can be used to prioritize and rehabilitate the war-damaged landscape services. (c) 2024 International Research and Training Center on Erosion and Sedimentation, China Water and Power Press, and China Institute of Water Resources and Hydropower Research. Publishing services by Elsevier B.V. on behalf of KeAi Communications Co. Ltd. This is an open access article under the CC BY- NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

During the final metres of the powered descent of Apollo 11, astronauts Neil Armstrong and Buzz Aldrin lost sight of the lunar surface. As the retro-rockets fired towards the lunar dust - or regolith - to decelerate the spacecraft, soil erosion occurred and the blowing dust led to severe visual obstruction. After a successful landing, the presence of dust continued to impact the mission with adverse effects including respiratory problems and difficulty in performing tasks due to clogging of mechanisms, amongst others. As these effects were observed in subsequent missions, the dust problemwas identified as one of the main challenges of extra-terrestrial surface exploration. In this work, the focus is placed on dust dispersal, which arises from the interaction between a rocket exhaust flow - or plume - and the planetary surface. Termed plume-surface interactions (PSI), this field of study encompasses the complex phenomena caused by the erosion and lofting of regolith particles. These particles, which are ejected at high-speeds, can lead to damage to the spacecraft hardware or a reduction in functionality. Moreover, plumes redirected back towards the landers can induce destabilising loads prior to touch-down, risking the safety of the landing. To achieve a sustained presence on the Moon, as planned by NASA's Artemis programme, it is essential that PSI are well understood and mitigating measures are put in place, particularly if spacecraft are to land in the vicinity of lunar habitats. Although experimental work began in the 1960s and mission PSI were first recorded in 1969, a fundamental understanding of this phenomena has not yet been achieved. In this paper, a compendium of experimental PSI is presented, identifying the main challenges associated with the design of tests, stating important lessons learnt and the shortcomings of available experimental data and findings. Lastly, recommendations for future experimental work are presented.

Simulating synthetic aperture radar (SAR) images of crater terrain is a crucial technique for expanding SAR sample databases and facilitating the development of quantitative information extraction models for craters. However, existing simulation methods often overlook crucial factors, including the explosive depth effect in crater morphology modeling and the double-bounce scattering effect in electromagnetic scattering calculations. To overcome these limitations, this article introduces a novel approach to simulating SAR images of crater terrain. The approach incorporates crater formation theory to describe the relationship between various explosion parameters and craters. Moreover, it employs a hybrid ray-tracing approach that considers both surface and double-bounce scattering effects. Initially, crater morphology models are established for surface, shallow burial, and deep burial explosions. This involves incorporating the explosive depth parameter into crater morphology modeling through crater formation theory and quantitatively assessing soil movement influenced by the explosion. Subsequently, the ray-tracing algorithm and the advanced integral equation model are combined to accurately calculate electromagnetic scattering characteristics. Finally, simulated SAR images of the crater terrain are generated using the SAR echo fast time-frequency domain simulation algorithm and the chirp scaling imaging algorithm. The results obtained by simulating SAR images under different explosion parameters offer valuable insights into the effects of various explosion parameters on crater morphology. This research could contribute to the creation of comprehensive crater terrain datasets and support the application of SAR technology for damage assessment purposes.

Earth's terrestrial surfaces commonly exhibit topographic roughness at the scale of meters to tens of meters. In soil- and sediment-mantled settings topographic roughness may be framed as a competition between roughening and smoothing processes. In many cases, roughening processes may be specific eco-hydro-geomorphic events like shrub deaths, tree uprooting, river avulsions, or impact craters. The smoothing processes are all geomorphic processes that operate at smaller scales and tend to drive a diffusive evolution of the surface. In this article, we present a generalized theory that explains topographic roughness as an emergent property of geomorphic systems (semi-arid plains, forests, alluvial fans, heavily bombarded surfaces) that are periodically shocked by an addition of roughness which subsequently decays due to the action of all small scale, creep-like processes. We demonstrate theory for the examples listed above, but also illustrate that there is a continuum of topographic forms that the roughening process may take on so that the theory is broadly applicable. Furthermore, we demonstrate how our theory applies to any geomorphic feature that can be described as a pit or mound, pit-mound couplet, or mound-pit-mound complex. Earth's surface is constantly roughened by processes that operate quasi-randomly in space and time. For example, in forest settings, trees that topple will uproot soil and deposit a mound and excavate a pit, leaving a pit-mound couplet on the surface. With time, this topographic signature decays due to geomorphic processes rearranging sediment and soil on the surface. In this paper, we develop theory that explains topographic roughness as a balance between processes that create roughness and those that destroy it. We consider several different mechanisms (desert shrub mounds, tree uprooting, river channel avulsions, and impact cratering) and develop a general theory for topographic roughness that applies to many settings. We further Tdevelop theory that allows for a very wide range of natural features that may not be well-described by simple geometric functions. Topographic roughness at scales of meters to tens of meters reflects a balance between roughening and smoothing processes Analytical expressions for topographic roughness exist for many settings Increasingly high-resolution topographic data is a valuable resource for extracting process-specific information from topographic roughness

Paramyrothecium comprises saprobic and plant pathogenic members. Eight plant-pathogenic Paramyrothecium species have been recorded in Asia, America, and some parts of Africa and Europe. Among the commonly reported species are P. roridum and P. foliicola. Several Paramyrothecium species are associated with coffee leaf spots, muskmelon crown rot, and eggplant crater rot. Paramyrothecium is commonly found in soil, decaying plant material, and diseased fruits, stems, and leaves of several plant species. The life cycle of Paramyrothecium species includes an asexual stage throughout disease development, with no sexual morphs reported. Environmental factors, such as temperature and humidity, influence the distribution and prevalence of Paramyrothecium. Paramyrothecium-associated diseases occur through various mechanisms, including wind and rain dispersal of conidia, contaminated soil, and plant debris. Paramyrothecium disease development can be exacerbated when the soil is wet and plant tissues are damaged, which served as pathogen entry. Adequate water management, soil sanitation, and proper handling of crops are important to minimize losses in commercial crop production. Several biological control agents and pesticides have also been reported to control the pathogen and the associated disease.

After landing in the Utopia Planitia, Tianwen-1 formed the deepest landing crater on Mars, approximately 40 cm deep, exposing precious information about the mechanical properties of Martian soil. We established numerical models for the plume-surface interaction (PSI) and the crater formation based on Computational Fluid Dynamics (CFD) methods and the erosion model modified from Roberts' Theory. Comparative studies of cases were conducted with different nozzle heights and soil mechanical properties. The increase in cohesion and internal friction angle leads to a decrease in erosion rate and maximum crater depth, with the cohesion having a greater impact. The influence of the nozzle height is not clear, as it interacts with the position of the Shock Diamond to jointly control the erosion process. Furthermore, we categorized the evolution of landing craters into the dispersive and the concentrated erosion modes based on the morphological characteristics. Finally, we estimated the upper limits of the Martian soil's mechanical properties near Tianwen-1 landing site, with the cohesion ranging from 2612 to 2042 Pa and internal friction angle from 25 degrees to 41 degrees. (c) 2024 Published by Elsevier B.V. on behalf of China University of Mining & Technology. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Wars have serious negative effects on the total environment. This study reviews 193 case studies worldwide in order to better understand these impacts and their potential management before, during and after war. The synthesis of the evidence shows that military actions damage landscape resources. Aerial bombings have great negative impacts by damaging environmental conservation efforts, destroying trees, disturbing soilscapes and undermining soil health. In addition, war exterminates wildlife and their ecological niches and contributes to atmospheric and water pollution. Overall, military leaders and personnel have shown little concern about these impacts. Limited postwar restoration activities are also undertaken to reduce war-driven environmental impacts. The study highlights some good practices on how to manage the total environment during the warfare. Therefore, communities must share best lessons to remain in a sustainable peace, restore the war -damaged environment, and enhance sustainable economic development.

Water ice has been found in the permanently shadowed regions of impact craters around the lunar South Pole, which makes them ideal areas for in situ exploration missions. However, near the rim of impact craters, construction and exploration activities may cause slope instability. As a result, a better understanding of the shear strength of lunar soil under higher stress conditions is required. This paper mainly uses the finite element method to analyze slope stability to determine the position and shape of the slip surface and assess the safety factor. The height and gradient of the slope, the shear strength of lunar soil, and the lunar surface mission all influence the stability of the slope. We also analyze the soil mechanical properties of a soil slope adjacent to the traverse path of the Chang'E-4 Yutu-2 rover. Determining the stability of the slope at the lunar South Pole impact crater under various loading conditions will enhance the implementation of the lunar surface construction program. In this respect, this paper simulates a lunar mission landing at the Shackleton and Shoemaker craters and indicates that areas with higher cohesion lunar soil may be more stable for exploration in the more complex terrain of the South Pole.