Permafrost degradation on the Tibetan Plateau (TP) has triggered widespread retrogressive thaw slumps (RTSs), affecting hydrology, carbon sequestration and infrastructure stability. To date, there is still a lack of long-term monitoring of RTSs across the TP, the thaw dynamics and comprehensive driving factors remain unclear. Here, using time-series Landsat imagery and change detection algorithm, we identified RTSs on permafrost regions of the TP from 1986 to 2020. Existing RTSs inventories and high-resolution historical imagery were employed to verify the identified results, the temporal validation of RTSs disturbance pixels demonstrated a high accuracy. In the study area, a total of 3537 RTSs were identified, covering a total area of 5997 ha, representing a 26-fold increase since 1986, and 69.2 % of RTSs formed since 2010. Most RTSs are located on gentle slope (4-12 degrees) at elevations between 4500 m and 5300 m, with a tendency to form in alpine grassland and alpine meadow. Annual variations in RTSs area exhibited a significant positive correlation with minimum air temperature, mean land surface temperature, and annual thawing index, while it showing a significant negative correlation with the decrease in downward shortwave radiation. Spatially, RTSs were more common in areas with higher soil water content and shallower active layer. Landsat imagery captured the vast majority of RTSs on the TP and revealed interannual disturbance details, but the 30 m resolution remains inadequate for delineating the refined boundaries of some micro-scale (< 0.18 ha) RTSs. Detected RTSs disturbances on the TP will aid in hazard management and carbon feedback assessments, and our findings provide novel insights into the impacts of climate change and permafrost environments on RTSs formation.

The study examines the toxicity of cadmium (Cd), microplastics (MPs) and their combined pollution on wheat plants, focusing on Cd accumulation and alterations to soil physical and chemical properties. To provide guidance for understanding the physiological and ecological responses of wheat to Cd and MPs contamination. Using a soil pot experiment, the individual and combined impacts of Cd (0 mg kg(-)(1) and 5 mg kg(-)(1)) and polyvinyl chloride microplastics (PVC-MPs) (0%, 0.5%, 1.0%, and 5.0%) on various aspects of wheat growth were assessed. Partial least square (PLS) model was employed to analyze the quantitative relationship between wheat growth indicators and various physicochemical parameters. Results revealed that the PVC-MPs significantly suppressed wheat growth parameters, photosynthetic efficiency, and chlorophyll content. As the level of contamination increased, the damage to wheat chloroplasts became more severe, leaf thickness reduced, and canopy temperatures rose. Conversely, root morphology parameters and Cd accumulation in wheat plants exhibited a declining trend. Moreover, soil fertility indicators and the activities of soil urease, acid phosphatase and dehydrogenase increased in correlation with higher concentrations of PVC-MPs. The PLS model identified stomatal conductance as the critical controlling factor influencing wheat growth under the combined stress of PVC-MPs and Cd. Overall, co-occurring Cd and PVC-MPs can change wheat plant performance and soil traits. These findings provide crucial insights into the physiological and ecological impacts of Cd and microplastic co-pollution in wheat-soil systems.

Permafrost degradation is one of the most significant consequences of climate change in the Arctic. During summers, permafrost degradation is evident with cryospheric hazards like retrogressive thaw slumps (RTSs) and active layer detachment slides (ALDs). In parallel, the Arctic has become a popular tourist destination for nature-based activities, with summer being the peak touristic season. In this context, cryospheric hazards pose potential risks for tourists' presence in Arctic national parks and wilderness in general, like in the Yukon. This essay provides the basis for investigating further periglacial, geomorphological and tourism intersections, highlighting the critical need for future interdisciplinary research on thawing permafrost impacts. More so, this requires moving beyond the predominant focus on permafrost impacts on infrastructure and to also consider the direct threats posed to human physical presence in Arctic tourist destinations affected by permafrost degradation. Such interdisciplinary approach is critical not only to mitigate risks, but also to provide policy- and decision-makers with valuable insights for implementing measures and guidelines.

Srinagar city is located in the heart of the Kashmir valley of the northwest Himalaya and is the largest urban center in the seismically active region. As yet, no direct deformation measurement or observation of any kind has been made in Srinagar and the surrounding areas using InSAR. We detect and quantify the ground deformation in the city's western flank using the InSAR time series. Stanford Method for Persistent Scatterer (StaMPS) is employed to process Sentinel-1A radar images acquired between 2015 and 2022 for ascending (161 scenes) and 2020 to 2022 for descending track (31 scenes). Generated velocity fields were decomposed into vertical rate maps, revealing a deformation of 17 mm year(-1) for ascending and 19 mm year(-1) for descending track. Time series analysis exhibits an identical deformation rate for both tracks on concurrent dates. Time-series GPS data was employed to validate the outcomes of our InSAR analysis. A field survey conducted in the main zone of deformation revealed extensive damage to structures in the form of wide cracks. Such cracks develop in older infrastructure (similar to 8 years) due to cumulative ground deformation over several years. Geotechnical investigation and strength calculation on a 30-m borehole of the subsiding region shows a vertical domination of high void, floodplain soils, with appreciable amounts of decomposed organic matter and lower shear strength parameters that are prone to volume reduction and particle rearrangement upon wetting and loading. The overall relevance of this study is in detecting and quantifying such subsidence in the Kashmir basin using SAR remote sensing. We also seek to establish a linkage of this deformation with the local stratum to allow for more consideration and efficient planning of civil infrastructure in the subsidence-prone regions of the citified zone and appropriate management of the subsidence-induced risk.

Studies of the impact of nitrification inhibitors (NIs), specifically DMPP and DMPSA, on N2O emissions during hot moments have produced conflicting results regarding their effectiveness after rewetting. This study aimed to clarify the effectiveness of NIs in reducing N2O emissions by assessing residual DMP concentration and its influence on ammonia-oxidizing bacteria (AOB) in two pot experiments using calcareous (Soil C, Calcic Haploxerept) and acidic soils (Soil A, Dystric Xerochrepts). Fertilizer treatments included urea (U), DMPP, and DMPSA. The experiments were divided into Phase I (water application to dry period, 44 days) and Phase II (rewetting from days 101 to 121). In both phases for Soil C, total N2O emissions were reduced by 88% and 90% for DMPP and DMPSA, respectively, compared with U alone. While in Phase I, the efficacy of NIs was linked to the regulation of AOB populations, in Phase II this group was not affected by NIs, suggesting that nitrification may not be the predominant process after rewetting. In Soil A, higher concentrations of DMP from DMPP were maintained compared to Soil C at the end of each phase. Despite this, NIs had no significant effect due to low nitrification rates and limited amoA gene abundance, indicating unfavorable conditions for nitrifiers. The study highlights the need to optimize NIs to reduce N2O emissions and improve nitrogen efficiency, while understanding their interactions with the soil. This knowledge is necessary in order to design fertilization strategies that improve the sustainability of agriculture under climate change.

To reduce the potential threat of soil loss due to ephemeral gullies, it is crucial to adopt Best Management Practices (BMPs) that prevent damage to landscapes by reducing sediments load. The current research evaluated the impact of five BMPs, including cover crops, grassed waterways, no-till, conservation tillage, and riparian buffer strips for reduction of sediment load from sheet/rill, and ephemeral gully erosion in an agricultural watershed in Southern Ontario, Canada. The study aimed to automatically calibrate AnnAGNPS using genetic algorithm and the most sensitive parameters of the model identified using a combination of Latin Hypercube Sampling (LHS) and One-At-a-Time (OAT) approach. It also utilized the calibrated model to simulate the effectiveness of BMPs in reducing the average seasonal and annual sediment loads from both sources of erosion (sheet/rill, and ephemeral gully) to determine the most effective practices. Riparian buffer strips were consistently successful in decreasing average seasonal sediment load of sheet/rill erosion, with an average reduction efficiency of 72 % in Spring, 64 % in Summer, 65 % in Fall, and 76 % in Winter. In terms of reducing average seasonal sediment load from ephemeral gully erosion, grassed waterways proved to be the most effective BMPs. They showed efficiency of 90 % in Spring; 83 % in Summer; 79 % in Fall; and 75 % in Winter. Considering the average annual sediment load, riparian buffer strips were consistently successful in decreasing average annual sediment load of sheet/rill erosion, with 69% reduction efficiency. Similarly, grassed waterways were the most effective BMPs for reducing average annual sediment load of ephemeral gully erosion, with an efficiency of 81 %. Additionally, grassed waterways were found to be the most efficient BMPs for reducing average annual total sediment load with reduction efficiency of 71 %. These results demonstrate the importance of implementing effective BMPs to address ephemeral gully erosion in watersheds where ephemeral gullies are the main source of erosion.

The issue of bridge end bumps is a critical concern in the failure of bridge and bridge approaches. A series of novel centrifuge tests utilizing a ring model box were conducted to investigate settlement and its induced damages at the bridge approach. A new mitigation method, the deep-seated slab, for bridge end bumps was modeled in the test. This study analyzed the decisive role of pavement stiffness, soil modulus, and load cycles on deformation from the perspective of structure-soil interaction under standard traffic load conditions. The test results show that when deep-seated slabs are used, the deformation of the bridge approach follows an exponential decay pattern, eventually stabilizing after approximately one slab length. Furthermore, the upper and lower bridges exhibit distinct damage modes, i.e., the bridge damage by wheel collision at the upper bridge and the pavement damage by wheel impact at the lower bridge. The damage zone on the pavement is approximately 1.7 times the wheel width and the damage zone on the bridge 2.6 times. Finally, a predictive model for the deformation of bridge approaches was proposed, considering the effect of pavement stiffness, subgrade soil modulus, and load cycles. The relationship between the deformation and the three normalized variables conforms to the quadratic polynomial function.

This paper describes the lithic aggregates from Sitwe 23 (SW23), a Stone Age locality in a previously unstudied region of the northern Luangwa Valley, Zambia. This area yielded two surface lithic scatters containing abundant artifacts derived from Pleistocene sediments on uplifted terrain and exposed by recent erosion on two adjacent terraces. The scatters are time-averaged palimpsests formed by deflation, but most of the lithics lack evidence of significant fluvial transport or post-depositional damage, indicating minimal horizontal displacement. Typological and attribute analyses of samples from both spurs reveal predominantly simple and expedient core and flake technologies, as well as sophisticated biface manufacture and Levallois technique producing flakes and points that are differentially distributed between the terraces. The artifacts identified in this analysis include types conventionally considered diagnostic of the Acheulean, Sangoan, and Middle Stone Age, suggesting that the collections may document one or more temporal windows during the Chibanian age (770-126 ka). Whether artifacts in these samples were originally deposited sequentially or concurrently is not yet known and alternative hypotheses are presented and discussed. The collections are compared to sites in Zambia and the northern Lake Malawi basin and found to be similar technologically but typologically different. Given the paucity of previously known Ston Age archaeological sites in the region, our work now demonstrates that northern Luangwa has significant archaeological potential and deserves further study. Cet article d & eacute;crit les agr & eacute;gats lithiques de Sitwe 23 (SW23), un site de l'Acirc;ge de pierre situ & eacute; dans une r & eacute;gion auparavant non & eacute;tudi & eacute;e de la vall & eacute;e septentrionale de Luangwa en Zambie. Deux dispersions lithiques en surface, sur deux terrasses adjacentes, ont & eacute;t & eacute; identifi & eacute;es sur un terrain sur & eacute;lev & eacute; et expos & eacute;s par une & eacute;rosion r & eacute;cente, chacune contenant de nombreux artefacts provenant de s & eacute;diments pl & eacute;istoc & egrave;nes. Ces dispersions sont des palimpsestes moyenn & eacute;s dans le temps, form & eacute;s par d & eacute;flation, mais la plupart des artefacts lithiques ne montrent pas d'& eacute;vidences de transport fluvial significatif ou de dommages post-d & eacute;positionnels, indiquant un d & eacute;placement horizontal minimal. Les analyses typologiques et d'attributs des deux zones r & eacute;v & egrave;lent la pr & eacute;dominance d'une technologie d'& eacute;clats et de nucleus simple et exp & eacute;ditive, combin & eacute;e & agrave; une fabrication sophistiqu & eacute;e de bifaces ainsi que d'& eacute;clats et de pointes de technique Levallois qui sont r & eacute;partis de mani & egrave;re diff & eacute;rentielle entre les terrasses. Les artefacts identifi & eacute;s dans cette analyse comprennent des types g & eacute;n & eacute;ralement consid & eacute;r & eacute;s comme diagnostiques de l'Acheul & eacute;en, du Sangoan et du Middle Stone Age, sugg & eacute;rant que les collections pourraient documenter une ou plusieurs fen & ecirc;tres temporelles du Chibanien (770-126 ka). Comme on ignore si ces art & eacute;facts ont & eacute;t & eacute; d & eacute;pos & eacute;s de mani & egrave;re s & eacute;quentielle ou simultan & eacute;e, diff & eacute;rentes hypoth & egrave;ses sont pr & eacute;sent & eacute;es et discut & eacute;es. Des comparaisons de ces collections & agrave; d'autres sites en Zambie et dans le bassin septentrional du lac Malawi r & eacute;v & egrave;lent qu'elles sont technologiquement similaires mais typologiquement diff & eacute;rentes. Compte tenu du manque de sites arch & eacute;ologiques de l'Acirc;ge de pierre connus dans la r & eacute;gion, nos travaux d & eacute;montrent d & eacute;sormais que le nord de vall & eacute;e de la Luangwa poss & egrave;de un potentiel arch & eacute;ologique significatif et m & eacute;rite des recherches suppl & eacute;mentaires.

It has been confirmed that microplastics (MPs) are present in the environment. This study simulated secondary PE-MPs via aging and mechanical processes to evaluate their effects on Pak choi (Brassica rapa L.) over 21 d. Two common pollutants, dichlorodiphenyltrichloroethane (DDT) and naphthalene, were used in the combined toxicity tests. The results indicated that the growth of Pak choi was significantly inhibited after exposure to secondary PE-MPs, and the combined effects were antagonistic, owing to the adsorption capacity of secondary PE-MPs to DDT and naphthalene. Oxidative stress in Pak choi can be markedly affected, leading to oxidative damage to plant cells. The moisture content, soil bulk density, soil density, cation exchange capacity (CEC), and FDA hydrolase in the planted soils increased in the treated groups, and the TOC content changed significantly. We also found that the microbial composition of the soil in the DDT and naphthalene groups showed more significant alterations than that in the other groups. Alpha diversity analysis showed that species diversity increased in the combined groups but indicated a clear downward trend in the single MPs groups. This study suggests that secondary PE-MPs harm the growth of Pak choi and can change soil properties, revealing the harm to the ecosystem of MPs in the soil.

- This research proposes a solution to improve the system for monitoring relevant environmental parameters using sensors for flood mitigation. Sensors are used to collect data regarding farm flood situation. The collected data are trained for a classification model to activate the solar-powered water pump to mitigate flood incidents in a flood-prone area. The system helps farmers to monitor real-time environmental parameters relevant to farming operations and flood including soil moisture level, water level, and water flow speed in a nearby canal that provides water to the farm. To reduce flood damage, the system assists to drain the excessive water to prevent prolonged submerging of the crop. The devices are designed to use the electricity from solar power, so the system is practically used outdoor where an electricity cord is difficult to setup. Experimental results show that the sensing data from the deployed sensors are accurate. The generated prediction models give the high performance with average of 1.0, 0.97, and 0.93 F-1 score for no-flooding, mild-flooding, and severe flooding respectively.