Loess landforms in the Loess Plateau are typical landforms in arid and semiarid areas and have a significant impact on the environment and soil erosion. Quantitative analyses on loess landform have been employed from various perspectives. Peak intervisibility can provide the potential topographic information implied in the visual connectivity of peaks, however, its application in loess landform analysis remains unexplored. In this study, the interwoven sightlines among peaks, representing peak intervisibility, were extracted from the digital elevation model and simulated into a peak intervisibility network (PIN). Nine indices were proposed to quantify the PIN. Through a case study in Northern Shaanxi, China, three tasks were conducted, including, landform interpretation, spatial pattern mining, and landform classification. The main findings are as follows: (1) PIN responds to terrain morphology and is beneficial for loess landform interpretation. (2) The spatial patterns of PIN indices are heterogeneous and strongly coupled with the terrain morphologies, showing anisotropy and autocorrelation in spatial variations. (3) Using the light gradient boost machine classifier, the PIN index-based classification reaches a mean accuracy of 86.09%, an overall accuracy of 86% and a kappa coefficient of 0.84. These findings shed light on the applicability of PIN in loess landform analysis. Peak intervisibility not only enriches the theories and methodologies of relation-based digital terrain analysis, but also enhances our comprehension of loess landform genesis, morphology, distribution, and evolution.

Due to the effects of global climate change, the permafrost temperature in the Qinghai-Tibet Plateau (QTP) has rapidly increased over the past decades. The development of thermokarst landforms is one distinctive indicator of permafrost degradation, while the change of the rate of permafrost degradation in recent 10 years has not been systematically investigated in QTP. In this paper, the annual average growth rate (AAGR) of ground deformation, the change of thaw slump areas, and the change of active layer thickness (ALT) of thermokarst landforms are monitored integrating SAR (synthetic aperture radar) and optical images for years 2007 to 2020 in Qilian Mountain, northern QTP. The ground deformation rate and seasonal amplitude were estimated by InSAR method, and the descending and ascending InSAR data are compared the validate the results. Based on the deformation results, AAGR was introduced to evaluate the permafrost degradation degree. Moreover, the ALT were estimated based on the seasonal deformation amplitude and Stefan model. The spatio-temporal characteristics of ground deformation and its relationship with thaw slump and temperature are explored. Experimental results show that the deformation rate increased about 150 % from 2007 to 10 to 2017-20. The maximum AAGR of deformation rate in the study area can reach 20.6 %. The thaw slump area has an obvious trend of expansion from 2009 to 2015, and its distribution agreed well with the deformation map. The ALT results ranged from 0.5 m to 2.8 m, indicating an obvious increase trend from 2007 to 2020. Based on the estimated increased ground deformation, thaw slump area, and ALT, it is inferred that frozen ground was undergoing serious degradation in the last 10 years. This study demonstrates the capability of multi-temporal InSAR in observing the accelerated permafrost thaw-freezing process and monitoring the permafrost parameters.

Background. Agricultural lands play a key role in ensuring the food security of the population and the development of the country's economy. However, excessive wetting poses a significant threat to these lands, as a result of which the conditions for the formation of soils with signs of glaciation and low fertility are formed within the lower relief elements, which significantly reduces their potential. In order to highlight the problems of geospatial identification of micro -recessed landforms (MRLF) on agricultural lands, the article uses spectral indices based on the data of RSE. Methods. 6 spectral indices were selected for the research. They were used to obtain data on areas of soil subsidence on arable lands, namely: NDWI, NWI, NDMI, NDVI, OSAVI, WRI. Solving research tasks involved the use of data from the Sentinel -2A satellite system. In order to visualize the spread of MRLF on the research territory, a high -resolution image (0.2 m per 1 pixel) obtained in the Digitals Professional 5.0 software was used. Processing and geospatial visualization of the RSE data were performed in the Arc Map environment of the Arc GIS 10.8 program using the raster calculator tool. Results. Within the reference fields, the dynamics of the values of water and vegetation indices were constructed and analyzed, and the identification ability for the geospatial separation of soil areas with signs of hydromorphism was evaluated. It is shown that the identification capacity of the indices depends not only on the level of soil moisture, but also on the biomass of vegetation (scales of crop damage), which is indicated by the high information capacity of the traditional vegetation index NDVI. The most informative index ranges were established: for NDVI, the range is from -0.117 to -0.024 with an identification percentage of 98.0 %; for OSAVI - 78.0 % with a range of 0.255-0.313; for NDMI with a range variation of -0.041 to -0.149 and an identification percentage of 56.0. Conclusions. The results of remote identification of the areas of the MRLF enabled to obtain information about the moisture content of the soils of the arable lands of the research area. The ability of the specified indices during the geospatial identification of microrecessed landforms (MRLF) and soil areas within them with signs of hydromorphism was evaluated. It is demonstrated that the use of orthophotos with a resolution of 0.2 m per 1 pixel serves as important supporting aids of successful completion of the specified tasks. It was found that the identification ability of water indices on test fields without existing vegetation is too low. On the other hand, the shielding of the soil surface by vegetation with areas of damaged crops makes it possible to isolate MRLF. The obtained information can be used during the development of the methodology of soil science surveying and planning of largescale soil survey activities.

Geodiversity elements contribute significantly to local and global hydrological, biogeochemical and ecosystem services and as such, fire is a potentially disruptive force with long-term implications. from limiting karstic speleothems formation, to compounding impacts of peat-fire-erosion cycles. Geodiversity elements additionally possess important cultural, aesthetic, and environmental values, including the support of ecosystem services. Hence, assessments of potential fire damage should consider implications for land users, society, and culture, alongside the geomorphic impacts on geodiversity elements. With a view to providing a concise set of descriptors of the response of geodiversity elements to fire, we qualify and in places, quantify, how fire may degrade geosystem function. Where possible, we highlight the influence of fire intensity and frequency gradients, and cumulative fire, in the deterioration of geodiversity values. Geoconservation is integral to protected areas with implications from fire effected geodiversity functions and values presenting issues for management, with potential consequences extending through to delisting, degazetting, and resizing of protected areas. Future research in reserve systems should concentrate on understanding the synergistic and compounding effects of fire on the geophysical landscape. Geodiversity provides valuable benefits through its existence and function. Fire can degrade geodiversity elements in several ways, on vast spatial and temporal scales, with implications for geoconservation and protected areas management. Understanding recovery rates of geodiversity elements, and the cumulative impact of fire on geodiversity, requires further research.

Glacial landforms formed by multiple glaciations are well-preserved in the valleys around Karlik Mountain in the easternmost Tianshan range, Central Asia. These landforms are direct imprints of palaeoglaciers and represent important archives of past climatic and environmental conditions. Dating these landforms contributes to understanding the spatiotemporal variations of past glaciers and provides key information for reconstructing the palaeoclimate and palaeoenvironment in Central Asia. In this study, thirty-two boulder and bedrock samples were collected from two glaciated valleys on the southern slope of Karlik Mountain for terrestrial in situ cosmogenic nuclides (TCN)10Be surface exposure dating. Based on the geomorphic relationships and dating results, the innermost MS1 moraine complex was deposited during the Little Ice Age (LIA); the MS2 moraine complex was formed during the Late -glacial; the MS3 moraine complex was deposited during the global Last Glacial Maximum (LGMG); the MS4 moraine complex, which is the largest moraine complex, is marine oxygen isotope stage (MIS) 4 in ages; and the MS5 moraine complex, which is only preserved at the interfluve ridges, has a similar age to MS4. The age of MS4 demonstrates that the largest local last glacial maximum (LGML) occurred during the early part of the last glacial cycle rather than during the LGMG. The MS4 and MS5 glacial complexes imply that a large ice cap with outlet valley glaciers developed on the whole of Karlik Mountain during MIS 4. These ages, combined with previous landform mapping and dating on the northern slope of the mountain, show that glacial advances since MIS 4 in this mountainous area were restricted to the valleys, rather than large ice cap scale, which is consistent with moraine records in the other valleys across the Tianshan range. The pattern and nearly synchronous timing of palaeoglacier fluctuations during the last glaciation in arid Central Asia imply that the main determinant for glacier fluctuations in this region has been changes in precipitation brought by the westerlies during periods of low temperature.(c) 2023 Elsevier Ltd. All rights reserved.

This paper discusses the potential response of fluvial processes and landforms to the projected permafrost degradation and related hydrological change. Fluvial system structure is presented in the first of the paper along with permafrost controls over its functioning, which vary across fluvial system compartments. The distinction is drawn between primarily fluvial landforms that are expected to adjust to future hydrology with less permafrost constraints, and primarily cryogenic landforms evolving in line with permafrost disturbances. The influence of permafrost on fluvial action varies across compartments: on hillslopes, permafrost mostly controls the occurrence of surface runoff, in river valleys and channels, sediment erodibility, while thermal interaction is essential for growing thermo-erosional gullies. Observed and projected changes in permafrost and hydrology are outlined, and their relevance for cryo-fluvial evolution of fluvial systems is reviewed. Based on these projections, future changes in fluvial action in each compartment are discussed. On hillslopes, where permafrost exerts important controls on hillslope hydrology, fluvial activity of overland flow is expected to decrease following the active layer deepening and decreased overland flow duration. In erosional networks, controlled by thermal interaction between runoff and permafrost terrain, higher water temperature is expected to increase the occurrence and rates of thermo-erosional gully development. In river valleys and channels, where permafrost controls the erodibility of bed and bank material, the expected fluvial feedbacks vary across scales and stream orders, and include changes in seasonality of channel deformations, increased retreat rates in lower river banks and decreased, in higher banks, along with floodplain subsidence, and minor potential for complete destabilization of existing channel patterns. Future collateral effects of fluvial change include alterations of terrestrial biogeochemical cycles and societal impact that must be accounted for in climate change adaptation and mitigation strategies.

Nordenskiold Land in Central Spitsbergen, Svalbard is characterized as a high latitude, high relief periglacial landscape with permafrost occurring both in mountains and lowlands. Freezing and thawing of the active layer causes seasonal frost heave and thaw subsidence, while permafrost-related mass-wasting processes induce downslope ground displacements on valley sides. Displacement rate varies spatially and temporally depending on environmental factors. In our study, we apply Satellite Synthetic Aperture Radar Interferometry (InSAR) to investigate the magnitude, spatial distribution and timing of seasonal ground displacements in and around Adventdalen using TerraSAR-X StripMap Mode (2009-2017) and Sentinel-1 Interferometric Wide Swath Mode (2015-2017) SAR images. First, we show that InSAR results from both sensors highlight consistent patterns and provide a comprehensive overview of the distribution of displacement rates. Secondly, two-dimensional (2D) TerraSAR-X InSAR results from combined ascending and descending geometries document the spatial variability of the vertical and east-west horizontal displacement rates for an average of nine thawing seasons. The remote sensing results are compared to a simplified geomorphological map enabling the identification of specific magnitudes and orientations of displacements for 14 selected geomorphological units. Finally, June to December 2017 6-day sampling interval Sentinel-1 time series was retrieved and compared to active layer ground temperatures from two boreholes. The timing of the subsidence and heave detected by InSAR matches the thawing and freeze-back periods measured by in-situ sensors. Our results highlight the value of InSAR to obtain landscape scale knowledge about the seasonal dynamics of complex periglacial environments.

In this study we assess the total storage, landscape distribution, and vertical partitioning of soil organic carbon (SOC) stocks on the Brogger Peninsula, Svalbard. This type of high Arctic area is underrepresented in SOC databases for the northern permafrost region. Physico-chemical, elemental, and radiocarbon (C-14) dating analyses were carried out on thirty-two soil profiles. Results were upscaled using both a land cover classification (LCC) and a landform classification (LFC). Both LCC and LFC approaches provide weighted mean SOC 0-100 cm estimates for the study area of 1.0 +/- 0.3 kg C m(-2) (95% confidence interval) and indicate that about 68 percent of the total SOC storage occurs in the upper 30 cm of the soil, and about 10 percent occurs in the surface organic layer. Furthermore, LCC and LFC upscaling approaches provide similar spatial SOC allocation estimates and emphasize the dominant role of vegetated area (4.2 +/- 1.6 kg C m(-2)) and solifluction slopes (6.7 +/- 3.6 kg C m(-2)) in SOC 0-100 cm storage. LCC and LFC approaches report different and complementary information on the dominant processes controlling the spatial and vertical distribution of SOC in the landscape. There is no evidence for any significant SOC storage in the permafrost layer. We hypothesize, therefore, that the Brogger Peninsula and similar areas of the high Arctic will become net carbon sinks, providing negative feedback on global warming in the future. The surface area that will have vegetation cover and incipient soil development will expand, whereas only small amounts of organic matter will experience increased decomposition due to active-layer deepening.

High-resolution aerial images allow detailed analyses of periglacial landforms, which is of particular importance in light of climate change and resulting changes in active layer thickness. The aim of this study is to show possibilities of using UAV-based photography to perform spatial analysis of periglacial landforms on the Demay Point peninsula, King George Island, and hence to supplement previous geomorphological studies of the South Shetland Islands. Photogrammetric flights were performed using a PW-ZOOM fixed-winged unmanned aircraft vehicle. Digital elevation models (DEM) and maps of slope and contour lines were prepared in ESRI ArcGIS 10.3 with the Spatial Analyst extension, and three-dimensional visualizations in ESRI ArcScene 10.3 software. Careful interpretation of orthophoto and DEM, allowed us to vectorize polygons of landforms, such as (i) solifluction landforms (solifluction sheets, tongues, and lobes); (ii) scarps, taluses, and a protalus rampart; (iii) patterned ground (hummocks, sorted circles, stripes, nets and labyrinths, and nonsorted nets and stripes); (iv) coastal landforms (cliffs and beaches); (v) landslides and mud flows; and (vi) stone fields and bedrock outcrops. We conclude that geomorphological studies based on commonly accessible aerial and satellite images can underestimate the spatial extent of periglacial landforms and result in incomplete inventories. The PW-ZOOM UAV is well suited to gather detailed geomorphological data and can be used in spatial analysis of periglacial landforms in the Western Antarctic Peninsula region.