Geomorphological Environment Research Articles

진주 일대의 지형환경 특성과 주요 경관자원

진주 일대의 지형환경 특성과 주요 경관자원

Satellite‐Derived Bathymetry in Dynamic Coastal Geomorphological Environments Through Machine Learning Algorithms

AbstractIn the field of coastal geomorphology, advancements in space technology have revolutionized coastal mapping and understanding. Satellite‐derived bathymetry (SDB) research has progressed, focusing on various estimation methods using high‐resolution satellite imagery and in‐situ data. Challenges arise when applying these methods to the Indian coastline due to its turbid waters and intricate features such as creeks and deltas, laden with sediment and submerged rocks. A study aims to assess multivariate machine learning (ML) regression techniques for estimating bathymetric data. The study employs ground‐truth data and imagery from Aster, Landsat‐8, and Sentinel‐2 at distinct sites known for complex underwater landscapes. Several algorithms including Multiple Linear Regression, Support Vector Regressor, Gaussian Process Regression (GPR), Decision Tree Regression, K‐Neighbors Regressor, k‐fold cross‐validation with Decision Tree Regression, and Random Forest (RF) are evaluated for SDB. Results from the Vengurla Site show that using the Landsat‐8 data set with the GPR algorithm achieves R2 0.94, root mean squared error (RMSE) 1.53 m, and MAE 1.14 m, utilizing visible spectrum bands. At Mormugao, the Sentinel‐2 data set with GPR and RF algorithms attains R2 0.97 and RMSE 1.23 m, with GPR outperforming RF, having an MAE of 1.05 m compared to RF's 1.22 m. This study underscores the potential of ML regression techniques in overcoming challenges with using SDB for mapping coastal geomorphology, particularly in intricate underwater terrains and turbid waters by assimilating sophisticated algorithms and their refined cartographic representation.

Assessment of Groundwater Vulnerability to Seawater Intrusion Using GALDIT, SITE and SIVI Methods in Laspias River Coastal Aquifer System, NE Greece

This paper presents the investigation of groundwater vulnerability to seawater intrusion of the aquifer system in the coastal area of Laspias River, NE Greece, for the year 2023, by applying the GALDIT, SITE and SIVI methods, in the context of the groundwater management of the area. The relevant research works include the collection and analysis of data and information regarding the geological and geomorphological environment, as well as the hydrogeological system of the area. The calculation of the GALDIT, SITE and SIVI indices values is described, and the results from the application of the methods are presented, as well as the design of relevant groundwater vulnerability maps of the study area. This paper concludes with findings and proposals useful for the reliable assessment of the hydrogeological regime of the wider study area.

Evolution of karst rocky desertification and its response to land use changes in different geomorphologic environments

Studying the evolution of karst rocky desertification (KRD) in control areas of diverse geomorphologic types and its correlation with land use provides valuable insights for identifying priority areas and implementing effective treatment measures. Employing Remote Sensing (RS) and GIS, this research quantitatively examines the evolution of KRD and its relationship with land use in the karst mountain and gorge areas of Guizhou Province over the period 2010 to 2020. The findings reveal continuous improvement in KRD across the study areas, albeit with noticeable regional disparities. Notably, the karst mountain region exhibited significantly higher change areas and rates of KRD, non-KRD, light KRD, and moderate KRD compared to the gorge area, underscoring better desertification control in the former region. A discernible correlation emerges between different karst geomorphologic types, the distribution and changes in land use types, and the evolution of KRD. Land use change emerges as a pivotal factor influencing the improvement of KRD in these areas. Changes in land use patterns corresponded with a decrease in KRD in dry land, other woodland, grassland, and bare land across both regions. However, the response of KRD to land use patterns varied across control areas with different geomorphologic environments, resulting in geographical differentiation in KRD evolution. Key land use conversions, notably from shrubland to forestland and dry land to garden land in the gorge, and shrubland to forestland in the mountain, contributed significantly to KRD dynamics in these regions. Notably, in the gorge area, KRD primarily occurred in garden land, other woodland, dry land, and grassland. In contrast, in the mountain area, KRD was prevalent in shrubland, dry land, and grassland, highlighting distinct responses and contributions to its evolution. The study observes substantial land use change in KRD-improved areas, particularly in the gorge region. Notably, the responsiveness of KRD to woodland conversions (shrubland, forestland, other woodland) varied across different geomorphologic environments. The dynamics of rocky desertification occurrence (RDO) and the occurrence structure of KRD in various land use types exhibited significant differences between the two regions. The gorge area demonstrated generally higher RDO, with a relatively stable and simpler occurrence structure of KRD compared to the more dynamic and varied structure observed in the mountain area. The sequencing of KRD occurrence in both areas displayed stability in specific land use types, with varying intensities noted between them.

A GEO-DATABASE FOR 3D-AIDED MULTI-EPOCH DOCUMENTATION OF BRIDGE INSPECTIONS

Abstract. The recent collapse of bridges in Italy has prompted numerous studies on monitoring and maintenance. Many structures in Italy have been in service for over 50 years, necessitating new approaches to ensure their safety. To address this issue, Italy's Consiglio Superiore dei Lavori Pubblici (Superior Council of Public Works) has developed the Guidelines for Risk Classification and Management, proposing a multi-level approach to bridge management within a complex geomorphological environment. The guidelines outline a multi-level process that includes surveying the structures, conducting detailed inspections, and assigning risk classes based on hazard, exposure, and vulnerability. Current inspection processes are time-consuming and costly. Therefore, alternative monitoring technologies are crucial. Unmanned aerial vehicles equipped with cameras, laser technologies, and GPS systems offer flexible and cost-effective solutions for visual inspection. These technologies enable the collection of both quantitative and qualitative data, such as size, material properties, and overall condition. In this context, efficient data management and exploration systems are necessary to handle the vast amount of geo-referenced information. Multi-epoch databases play a crucial role in documenting the conditions of bridges and supporting a maintenance and structural health monitoring workflow. These databases can be utilized within a Bridge Management System to aid road managers in decision-making processes. Additionally, 3D exploration platforms provide visual analysis and highlight areas of interest within the structure. This work presents a multi-epoch geo-database that adheres to the Italian guidelines, offering optimized data management and queryability for 2D and 3D information. The entire process is designed using open-source and reproducible solutions.

Potential Ecological Risk Assessment and Source Analysis of Heavy Metals in Soil-crop System in Xiong'an New District

In order to evaluate the distribution characteristics of fluorine geochemistry in the surface soil and human health risk in Xiong'an New District, GIS spatial analysis and correlation analysis were used to analyze the depleted and enriched features and influencing factors of soil fluoride and to carry out the soil fluoride health risk assessment. The uncertainty of the health risk assessment results was studied based on the Monte Carlo stochastic simulation. The results showed that the average content of fluorine was 641 mg·kg-1, which was 1.34 times the background value of the national A-layer soil. The excess fluorine and high-grade samples accounted for more than 85%, and the overall soil fluorine content was relatively high. The average content of fluoride of the irrigation water samples was 0.85 mg·L-1, the spatial distribution characteristics of which were affected by the hydrochemical type and flow direction of shallow groundwater. The vertical spatial variation of soil fluoride, mainly affected by the vertical distribution of soil physicochemical properties such as soil organic carbon and texture, was not obvious. The depletion and enrichment of topsoil fluorine was mainly controlled by the geological background, and its spatial distribution was affected by external inputs, such as human factors (agricultural irrigation water, fertilization, and atmospheric dry and wet deposition). The soil fluoride content was significantly correlated with the iconic indicators of the geomorphological environment, including the content of Al2O3, Fe2O3, MgO, K2O, soil organic carbon (Corg.), cation exchange capacity (CEC), clay, and silt (P<0.01). The results of human health risk assessment showed that oral intake was the main exposure risk route of soil fluoride. The non-carcinogenic health risk index HQ of adults was less than 1, and the harm could be ignored. The probability of non-carcinogenic health risk exceeding the threshold for adults and children was 34.3% and 27.6%, respectively, and daily soil intake was the most sensitive parameter.

Morphological analysis of mineral grains from different sedimentary environments using automated static image analysis

The properties of sediment grain shape provide valuable information about the transport mechanisms in different sedimentary and geomorphological environments. With the emergence of new, high-resolution analytical techniques, it has become possible to quickly examine the grain shape properties of a large number of individual mineral grains. In this study, we used automated image analysis (Malvern Morphologi G3SE-ID) to investigate mineral particles of four sediment types from different depositional environments (sand sheet (1), floodplain (2) and fluvial channel deposits (3), Pleistocene infilling material of sand wedges (4), n = 20) in the Carpathian Basin (Central Europe). Our primary objective was to identify quantitative key variables that can help objectively distinguish certain geomorphological environments located in the Carpathian Basin. In our analysis and data processing (which included techniques such as hierarchical cluster analysis, Wilks' λ, Kruskal–Wallis, multivariate analysis of variance and principal component analysis) we focused on four variables related to grain shape: circularity (form), convexity (surface texture), solidity (roundness) and elongation (form). The form of sedimentary grains depends largely on the physical properties of their source area, while the roundness depends on the energy of the transport medium and the distance of transportation. Surface texture or convexity can change in a relatively short time in a fluvial environment.The study revealed that distinguishing geomorphological environments can be achieved by analyzing the circularity, convexity and solidity parameters of the sediment grains. Based on the established grouping, the analyses carried out with hundred repetitions showed that high sensitivity circularity, convexity and solidity variables were the most effective attributes regarding Kruskal–Wallis test statistics that provided significant (p < 0.001) results between the analyzed sedimentary environments, while the elongation was not able to provide significant results between the grouped samples. Statistical analyses of the MANOVA test with hundredfold repetitions showed significant differences between the derived groups. Wilks' λ test statistics and PCA showed that convexity and high sensitivity circularity discriminate the groups. Separate analyses of aeolian and fluvial sediments have been carried out. The Kruskal–Wallis analysis of variance showed the significant differences considering all four variables, and differences were also significant in the case of the MANOVA test. Wilks' λ test statistics and PCA showed that convexity, high sensitivity circularity and solidity discriminate the groups.According to our results, the circularity parameter can provide information about the transport distance, while the solidity parameter can indicate the transport energy. The convexity parameter can serve as an indicator of both transport distance, as well as post-depositional processes. Some infilling materials underwent multiple transport processes, including high energy aqueous, wind transport mechanisms, and the post-depositional alteration process (frost weathering), while others originated from sand-sheet covered areas (active during Pleistocene glacials). The solidity parameter proved effective in separating sediments with similarly high convexity values (smooth surface), which were, in our case, from recent aeolian and fluvial environments. This result was due to the investigated fluvial sediments that inherited their form and low level of roundness from their source area. Our research supports that aeolian transport is more effective in rounding the grains than the aqueous environment.Using automated static image analysis producing statistically stable results with hundreds of analyzed mineral grains provides useful indicators for paleogeographical reconstruction studies by investigating paleo and recent sediments.

CONCEPTUAL PRINCIPLES OF SUSTAINABLE DEVELOPMENT OF ACTIVE TOURISM AND RECREATION IN THE WESTERN REGION OF UKRAINE

The study of the tourism and recreation sphere in the context of the postulates of sustainable development is carried out by many researchers. In particular, geographical, economic, social, behavioral, legal and other aspects of sustainable tourism development are investigated. Our research mainly regulates the formation and organization of the active tourism product of the Western region of Ukraine and their compliance with the principles of sustainable development. The principles of organizing active tourism and recreation are also proposed. Separately, we emphasize recreational and tourist initiatives within nature protection territories, taking into account the natural and geographical environment: geological and geomorphological environment, climate, hydrological and forest-vegetation conditions. The process of active tourism management has a negative impact on the relief and vegetation of the territory (tourist digression). This is especially relevant now, when the Western region of Ukraine receives internally displaced persons as a result of the war with Russia, as well as due to uncontrolled tourist traffic and activities. Manifestations of tourist digression are observed on popular tourist routes within the borders of Chornohora, Gorgans, Svidivets, Beskids, Vododilno-Verkhovyna ridge, Chivchyns, Hryniavs. Therefore, the changes that tourism in western Ukraine underwent after the start of the full-scale war were outlined. The correspondence of active tourism products to the principles of sustainability of the development of the tourism and recreation sphere in general is suggested. Achieving the principles of sustainability must be ensured at various levels of the organization of the tourist process: administrative, economic, subject (tourist), local community level. At each of the levels of the organization of the principles of sustainability of the development of the tourism process, it is worth applying both direct (direct) and indirect (mediated) levers of influence.&#x0D; Direct levers provide for strict, scientifically based regulation of the number of tourists; restrictions (in some cases, closure) for visiting particularly valuable natural objects and territories; application of modern technological innovations that allow minimizing environmental pollution, etc. Non-compliance with established norms and rules involves the application of appropriate sanctions. Mediated methods are a more flexible way of influencing the behavior of tourists and are based on raising the level of their culture, environmental education, and fostering a tolerant attitude of the local population. Currently, methods of direct influence due to the growth of mass tourism in the Western region of Ukraine are key and require immediate implementation, especially at the local level.&#x0D; We believe that the concept of active tourism has the right to exist in the context of its understanding as overcoming space in an active way with or without the use of specialized vehicles, using mainly the physiological and psycho-emotional conditions of the body to achieve the goals (goals) of the trip: cognitive, scientific, educational , sports, nature conservation, etc.&#x0D; Tourism in the Western region of Ukraine (especially in its Carpathian part) has undergone changes since the start of a full-scale war on February 24, 2022, which is recorded by many organizations.&#x0D; All active tourism products developed and organized in the Western region of Ukraine must comply with the principles of sustainable development of the tourism sector in general.&#x0D; We believe that the goal of the principles will not be achieved only by declarative statements, which is characteristic of most regional development programs, but by coordinating the efforts of all stakeholders of the tourism process.&#x0D; Regional and local strategies and programs for the development of tourism, resorts, and recreation play an important role in forming the foundations of sustainable tourism development.&#x0D; Highlighting the international environment, we are talking about the experience of the countries of the world in ensuring the sustainability of the tourism process, participation in international and interregional programs, grants, etc. Among other stakeholders, the following are important: elements of the infrastructure that ensure the functioning of the destination, representatives of business, social sphere, marketing and advertising, legislation, executive power at various levels, the market of qualified specialists in the field of hospitality, tourism, and recreation.&#x0D; Key words: active tourism and recreation, sustainable development, Western region of Ukraine, tourism process.

Stone artefacts on the seabed at a submerged freshwater spring confirm a drowned cultural landscape in Murujuga, Western Australia

We report the discovery and identification of five ancient stone artefacts associated with a submerged freshwater spring at the underwater archaeological site WH1 in Murujuga (Dampier Archipelago), Western Australia. A limiting date applied to the site based on timing of inundation suggests it was occupied in the Late Pleistocene or Early Holocene. The site is situated well below the intertidal zone having been recorded at 14 m depth in Flying Foam Passage. This discovery highlights the high potential of these submerged springs as archaeological survey targets. We discuss results of a recent survey that expands the number of confirmed artefacts located at WH1 and the geomorphological context in a large calcareous depression associated with a freshwater source. This study demonstrates how submerged landscape research using a suite of technologies can reveal archaeological assemblages in this tropical geomorphological environment, and that adapted techniques could be applied to other tropical conditions such as mangrove coasts, large deltaic plains, or reef-building environments. There are likely thousands of drowned archaeological sites on the continental shelf of the tropics, extending from the intertidal zone to the lowest point of the culturally occupied landmass, at approximately 130 m below modern sea level.

Assessment of groundwater-driven dissolved nutrient inputs to coastal wetlands associated with marsh-coastal lagoons systems of the littoral of the outer Río de la Plata estuary

In coastal wetlands the hydrological dynamics and in particular the groundwater flows play a critical role in the establishment of wetlands and in the transport of salts and nutrients. The aim of the work is to analyze the role that groundwater discharge has in the dynamics of the dissolved nutrients of the wetland associated with the coastal lagoon and marshes of the Punta Rasa Natural Reserve, which is located on the coastal sector of the southern end of the Río de la Plata estuary. A monitoring network in the form of transects was generated in order to define groundwater flows and take samples of dissolved species of N and P. The presence of sandy sediments with similar granulometric profiles in all geomorphological environments determines that the underground flow occurs in a homogeneous aquifer. From the dunes and beach ridges the fresh to brackish groundwater flows with a very low hydraulic gradient towards the marsh and coastal lagoon. The contributions of N and P would derive from the degradation of the organic matter of the environment, in the case of the marsh and coastal lagoon also from the tidal flow and discharge of groundwater, and possibly from atmospheric sources in the case of N. Since in all environments oxidizing conditions dominate, nitrification is the main process which is why the most abundant species of N is the NO3−. Under oxidizing conditions, P has a greater affinity for the sediments in which it is mostly retained, registering it in low concentrations in water. The discharge of groundwater from the dunes and beach ridges provides dissolved nutrients to the marsh and coastal lagoon. However, the low hydraulic gradient and the dominant oxidizing conditions determine that the flow is scarce and that it only acquires relevance in the contribution of NO3−.

Worldwide Trends in Methods and Resources Promoting Geoconservation, Geotourism, and Geoheritage

This study aims to provide a systematic analysis of the literature of methods and resources supporting geoconservation and geotourism worldwide, while identifying current and future trends in the field. This paper offers a comprehensive bibliometric analysis which comprises the period of 2011–2021 after an in-depth systematic literature review of 169 papers, using Web of Science. The volume of research on these topics is growing rapidly, especially in Italy, Poland, Brazil, Russia, and China; these constitute the most productive countries. The main identified geomorphological environments are sedimentary, volcanic, aeolian, coastal, fluvial, and karstic. We discovered that the main methods for evaluating geoconservation and geotourism are geomorphological mapping, the study of economic values for geotourism, field work as a research tool, geoheritage management, documentation, exploration, and inventories of geoheritage at a regional level. The main determined resources are UNESCO Geoparks, educational activities, digital tools, geomanagement, economic values, geoitineraries, and geoeducation programs. To our knowledge, this is the first study dealing with methods and resources publicizing geoconservation and geotourism, worldwide. Knowing about the most successful methods and resources for promoting geoconservation and geotourism can definitely be useful for future endeavors in countries where geoheritage studies are starting to be developed.

THE DEVELOPMENT OF THE TERRITORY OF THE NORTHERN BLACK SEA AS A FACTOR IN THE ECOLOGICAL AND GEOMORPHOLOGICAL EVALUATION OF THE DEGREE OF THE SOIL COVER OF THE REGION

The article dwells upon the economic development of the territory of the Northern Black Sea Coast, which in various ways affected the state and transformation of its soil cover. An overview of historical sources, which outlines the forms of public order, which determined the possibilities and necessity of using land resources. The relevance of the purposeful analysis of archaeological and historical periodization in the economic development of the studied territory was substantiated, comments on the actual material on the probability of certain impacts on the quality of soil cover were presented, the stages during which the state of the soil was influenced by certain factors of natural and anthropogenic origin, the author's assessment of the existing at that time, problems regarding changes in the extent of spread of cultivated land and changes in their quality.&#x0D; The conclusions determine the need to focus the concentration of research efforts on the establishment of correlations and the emergence of patterns of soil formation in the geomorphological environment, its transformation as a result of population growth, the diversity of economic use, and powerful melioration measures. The variety of tectonic patterns in the orographic and river network, the variability of stratigraphic and lithological complexes of soil forming species, significant differences in the geomorphological structure, complex combinations of significant areas of distribution of "background" genetic types of soils and local areas of the spread of colorful soil cover, as well as historically determined sequences of settlement of the region make up the range of analysis of the history of land use.&#x0D; The given historical excursion points to the need to focus research efforts on establishing relationships and deriving regularities of soil cover formation in the geomorphological environment, its transformation as a result of population growth, a variety of economic uses, and powerful reclamation measures. This region of modern Ukraine, in our opinion, can be interpreted as a key one for the entire Black Sea region, as it encompasses the set of tectonic, lithological and geomorphological features of the environment, other components of the environment, characteristic of the entire region, including the variety of tectonic regularities in the orography and river network, reliable and probable tectonic disturbances and areas of ascending and descending tectonic movements of weak activity, variegation of stratigraphic and lithological complexes with increased and decreased foundation of the inclined undulating and horizontal flat plain on Neogene deposits, significant differences in the geomorphological structure of individual territories of the Black Sea region, due to the presence of various morphological features, genetic types of relief, the time of formation of various geomorphological taxa and the intensity of modern geomorphological processes, significant areas of distribution of "background" genetic types of soils (mainly at the interfluves), and local areas of the distribution of variegated soil cover due to the significant role of the relief of the earth's surface, the historically determined sequence of settlement of the region and, accordingly, a different degree of economic activity, caused by a change in the nature of economic activity - from local around settlements and in the coastal zone, to regional, associated with the expansion of agricultural production and the development of irrigated agriculture.

Driving effects of dynamic geomorphologic environments on gravitational erosion hazards: a case of the Baihetan drainage area of the Jinsha River, China

Driving effects of dynamic geomorphologic environments on gravitational erosion hazards: a case of the Baihetan drainage area of the Jinsha River, China

Research on lethal levels of buildings based on historical seismic data

Due to the influences of buildings, geographical and geomorphological environments, road conditions, etc., the probabilities and numbers of casualties in different areas after an earthquake are different. Accordingly, we propose the concept of the lethal level, which attains different grades representing the mortality rate of differing intensities. Different regions have unique lethal levels, and regional lethal levels are affected mainly by the proportion of each building type and the corresponding lethal level, as different types of buildings also have unique lethal levels. Based on data of 52 historical earthquake disasters, we constructed a lethal level calculation model and obtained the lethal level of each building type. The results reveal that the lethal level ranges of different building types are fixed and unequal; moreover, the ranges of different building types overlap each other. The lethal level range of adobe structures is 0.85–1, that of civil structures is 0.75–0.95, that of brick-wood structures is 0.6–0.9, that of brick-concrete structures is 0.33–0.6, that of wood structures is 0.2–0.35, and that of reinforced concrete structures is 0.1–0.25. Based on the lethal levels of these building types, the overall level of a region can be quantified and graded, and this classification does not depend on the geographical location or administrative boundaries. In pre-earthquake evaluation efforts, the lethal level of an area can be derived through field research. After an earthquake, the number of casualties can be quickly assessed based on the mortality rate corresponding to the intensity of the area. This approach can further provide scientific support for risk zoning and risk assessment research.

DEVELOPMENT OF GEOTOURISM IN ARCHEOLOGICAL SITE OF CHITHARAL, KANYAKUMARI DISTRICT TAMILNADU-AN INNOVATIVE APPROACH

Geotourism is an emerging form of tourism, based on the geological environment and geomorphological environment. The study area Chitharal (Kanyakumari district) is now preserved as the monument which has been declared to be of national importance under the ancient monuments and arecheological sites. The present work is mainly aimed to identify the potential area to conduct geological studies and field works. The outstanding geological features, gemorphological, stratigraphical, sedimentological and structural features of Chitharal has a national or to a small extent international relevance. Peninsular gneiss, Charnokite, Warkalai sandstones, Alluvium types of rock and rock particles are present in this study area. Because of the presence of hard rock with quartz veins and garnet patches and sedimentary rock the area has geological importance too.

Turner’s 1836 Alpine Crossing and the Little Ice Age Portrayed in Val Veny and Val Ferret; a Geography of the Sublime

The English artist J.M.W. Turner made his second visit to upper Val d’Aosta in 1836, after which he produced several significant paintings. Here, we accurately locate two of these works and relate them to the climatic and geomorphological environment of the time. We combine critical geomorphological and cultural geographic analyses to derive a more holistic appraisal of Turner’s artistic motivations and methods in his Alpine works. The first is a watercolour of Mont Rouge de Peuterey from across the Glacier du Miage. The second is a major oil painting re-imagining of the 1717 Triolet disaster which conflates the complex geomorphological processes of this rock-ice avalanche and subsequent outburst flood into a single dramatic scene. Turner’s visit coincided with the mid-nineteenth century maximum advance of glaciers in the region allowing him to witness dynamic geomorphological processes in close proximity. The precise viewpoints of these scenes demonstrate that Turner spent some time in the area to seek out preferred locations and that he was aware of considerable details of local history. The paintings speak of an immersion in the environment of the time, and their study yields fruitful insights into the complex relationships between geography and landscape art.

A Case Study of Initial Vegetation Restoration Affecting the Occurrence Characteristics of Phosphorus in Karst Geomorphology in Southwest China

Phosphorus (P) is one of the necessary nutrient elements in the process of plant growth and development. The temporal and spatial distribution characteristics of phosphorus content can not only reflect the soil structure and availability, but also affect the growth of wetland vegetation, the formation of the environment, and the process of vegetation succession. In this paper, taking Guizhou Caohai Nature Reserve as the research object, the temporal and spatial substitution method was used to study the distribution and influencing factors of soil total phosphorus (TP) and soil available phosphorus (AP) under different geomorphological environments (non-karst landforms, karst landforms, and geomorphology after vegetation restoration (5 years)). The results showed that (1) the TP content in the topsoil of the restored vegetation landform was generally higher than that in the topsoil of the karst landform and non-karst landform, and the distribution difference of the AP content in the three areas was slight. At the top, hillside, and foot of the mountain, the contents of TP and AP in the non-karst landform and karst landform decreased with increasing soil depth and accumulated at the foot of the mountain. (2) The results of the correlation analysis showed that the interpretation rates of TP and AP by each soil physicochemical factor were the highest, reaching 64–86%, while the interpretation rate of TP and AP by the combined action of multiple physicochemical factors was relatively small; in addition, there was a significant correlation between environmental factors and soil TP and AP (p &lt; 0.05). (3) Compared with unrepaired karst landforms, in the process of vegetation restoration (5 years), TP content has convergence between geomorphology after vegetation restoration and non-karst landforms, while AP content fluctuates greatly. The analysis showed that the changes in soil TP and AP contents were mainly affected by vegetation communities, while the changes in soil TP and AP contents in mountain areas were also affected by soil organic matter, pH, soil particle size, and climatic conditions.

Analysis of Extreme Temperature Variations on the Yunnan-Guizhou Plateau in Southwestern China over the Past 60 Years

Analysis of variations in 12 extreme temperature indices at 68 meteorological stations on the Yunnan-Guizhou Plateau (YGP) in southwestern China during 1960–2019 revealed widespread significant changes in all temperature indices. The temperature of the hottest days and coldest nights show significantly increasing trends, and the frequencies of the warm days and nights also present similar trends. The temperature of the coldest night has a significant and strong warming trend (0.38 °C/decade), whereas the frequency of frost days shows the fastest decrease (1.5 days/decade). Increases in the summer days are statistically significant, while a decreasing trend for the diurnal temperature range is not significant. Furthermore, there were significant differences in the changes of temperature indices between 1960–1989 and 1990–2019. Most parts of the YGP underwent significant warning, manifesting that the mountainous regions are relatively sensitive and vulnerable to climate change. The correlation coefficients between the temperature indices and various geographical factors (latitude, longitude, and height) reflect the complexity of regional temperature variability and indicate enhanced sensitivity of extreme temperatures to geographical factors on the YGP. It was also found that extreme temperatures generally had weaker correlations with the El Nino-Southern Oscillation, North Pacific Index, Southern Oscillation Index, North Atlantic Oscillation, and East Asian Summer Monsoon Index than with the South Asian summer monsoon index, Nino4 indices and Arctic Oscillation, and there were more insignificant correlations. Regional trends of the extreme temperature indices reflect the non-uniform temperature change over the YGP, which is due to the complex interaction between atmospheric circulation patterns and local topography. The results of this study have important practical significance for mitigating the adverse effects of extreme climatic changes, in particular for the YGP with its typical karst geomorphology and fragile ecological environment.

Hydrological regimes in different slope environments and implications on rainfall thresholds triggering shallow landslides

Assessing hazard of rainfall-induced shallow landslides represents a challenge for the risk management of urbanized areas for which the setting up of early warning systems, based on the reconstruction of reliable rainfall thresholds and rainfall monitoring, is a solution more practicable than the delocalization of settlements and infrastructures. Consequently, the reduction in uncertainties affecting the estimation of rainfall thresholds conditions, leading to the triggering of slope instabilities, is a fundament task to be tackled. In such a view, coupled soil hydrological monitoring and physics-based modeling approaches are presented for estimating rainfall thresholds in two different geomorphological environments prone to shallow landsliding. Based on the comparison of results achieved for silty–clayey soils characterizing Oltrepò Pavese area (northern Italy) and ash-fall pyroclastic soils mantling slopes of Sarno Mountains ridge (southern Italy), this research advances the understanding of the slope hydrological response in triggering shallow landslides. Among the principal results is the comprehension that, mainly depending on geological and geomorphological settings, geotechnical and hydrological properties of soil coverings have a fundamental control on the timing and intensity of hydrological processes leading to landslide initiation. Moreover, results obtained show how the characteristics of the soil coverings control the slope hydrological response at different time scales, making the antecedent soil hydrological conditions a not negligible factor for estimating landslide rainfall thresholds. The approaches proposed can be conceived as an adaptable tool to assess hazard to initiation of shallow rainfall-induced landslides and to implement early-warning systems from site-specific to distributed (catchment or larger) scales.

Applicability Evaluation of Landslide Vulnerability Criteria for Decision on Landcreep-Vulnerable Areas in South Korea

Landcreep, which is a natural hazard, frequently occurs in South Korea. However, despite many differences between general landslides and landcreep, landcreep is still treated as a kind of landslide. A bigger problem in this reality is that no verification has been made on whether the national landslide vulnerability criteria can be applied to the decision on landcreep-vulnerable areas. Therefore, this study was conducted to examine the applicability of the landslide vulnerability criteria for the decision on landcreep-vulnerable areas. For verification, first, as a result of a correlation analysis that extracted seven types of geomorphological environment criteria that are used in deciding landslide-vulnerable areas from 57 landcreep areas, a positive correlation was shown only in the slope type and the parent rock. Second, as a result of the evaluation of the landcreep area by applying the landslide vulnerability criteria, it was analyzed that 61.4% were areas with low or no possibility of the occurrence of landslides. Third, on the basis of the overlapping analysis of the landslide hazard map and landcreep areas, 67.6% were in Level 3 or lower, except for Levels 1 and 2, which had high hazards, and 21.5% were landcreep areas that were not included in the hazard levels. Applying the landslide vulnerability criteria for deciding on landcreep-vulnerable areas is not appropriate, and it is urgent to prepare landcreep vulnerability criteria.