Karst Areas Research Articles

Study on disaster-causing probability evaluation of gas pipeline in karst area.

In this paper, a disaster-causing probability evaluation method of gas pipelines in karst areas based on disaster system theory and vulnerability theory is proposed. The hazard evaluation index system of gas pipeline disaster events in karst areas is established from three aspects: the activity of disaster-prone environment, the risk of disaster factors and the vulnerability of disaster-bearing bodies. Combined with the advantages of information transmission and updating of the Bayesian network model, the hazard probability of disaster events is gradually calculated from a multi-level perspective. Based on the structural reliability theory, the vulnerability evaluation function of gas pipelines in karst areas is established by considering the interaction between disaster hazard intensity and disaster resistance ability. Meanwhile, the design checkpoint method and finite element simulation are used to calculate the vulnerability probability. Finally, a new disaster-causing probability evaluation approach for gas pipelines in karst areas is formed, which comprehensively considers the event hazard and the pipeline vulnerability. The work presented in this paper can provide a reference for the safety management and accident prevention of gas pipelines crossing the karst areas.

Integrating karst bare rock index (KBRI) into the CASA model to improve grassland aboveground biomass estimation in karst area, Southwest China

Integrating karst bare rock index (KBRI) into the CASA model to improve grassland aboveground biomass estimation in karst area, Southwest China

Impact of socioeconomic factors on vegetation restoration in humid karst areas of China: Evidence from a survey of 45 villages

Impact of socioeconomic factors on vegetation restoration in humid karst areas of China: Evidence from a survey of 45 villages

Effects of biochar on rainwater redistribution, soil water evaporation and desiccation cracking: A case study of limestone soil in karst areas of southwest China.

Soil desiccation cracking, which leads to increased water loss and the destruction of soil integrity, can significantly exacerbate drought conditions and soil degradation. Biochar derived from organic waste can effectively reduce soil desiccation cracking as a sustainable soil amendment. However, the effects of biochar on the entire process of rainfall infiltration, soil water evaporation, and subsequent desiccation cracking remain unclear. In this study, simulated rainfall-evaporation experiments were conducted on limestone soil in karst areas with severe water leakage and susceptibility to cracking, using improved soil with corn straw biochar (CSB), rice husk biochar (RHB), and bagasse biochar (BB) at 0%, 2%, 4%, and 6% application rates, respectively. Surface runoff (SR) and underground percolation (UP) were collected during rainfall events, whereas soil water storage (SWS) was measured after the rainfall events. Each sample was weighed at intervals during evaporation (3-5days) to monitor the soil water content, and the corresponding crack morphology was photographed. The results indicated that SWS increased by 6.23%-35.14% while UP decreased by 11.39%-49.95% for the different types of biochar compared to the control. Biochar application increased the evaporation rate, but reduced the evaporation loss rate of soil water, allowing the soil to maintain a high water content for a longer evaporation period. The application of biochar inhibited crack propagation and reduced the final cracking degree, particularly when BB was applied. The biochar-amended soil had a smaller had lower crack ratio (Rcr), mean crack width (wcr), box-counting fractal dimension (Db), and crack network connectivity (Cnet) compared to the control. Based on our results, we suggest the application of 6% CSB or BB to limestone soils in karst areas. This study provides a scientific basis for the use of biochar to increase soil water content and minimise cracking.

Study on the Influence of Expressway Construction on Soil Environment in Karst Area of Guangxi, Southwest China

Study on the Influence of Expressway Construction on Soil Environment in Karst Area of Guangxi, Southwest China

The Cyrenaica Karst Project: Karst Geomorphology and Caves, Al-Jabal Al-Akhdar, NE Libya

This paper introduces the Cyrenaica Karst Project: a collaboration project between the University of Benghazi, Libya and the Hyblean Center of Speleo-hydrogeological of Ragusa, Italy. Among the objectives of the project there are: study the karst geomorphology and caves of Al-Jabal Al-Akhdar, construction of a speleological model consistent with the geodynamic evolution and climate changes taken place in the Tethyan-Mediterranean region; those with application fall-outs into the local socio-economic framework addressing the finding out and protection of new water resources, the mapping of man altered areas, potentially at risk of instability and/or sinking because of the presence of karst voids, and the institution of Karst Geosites and Geopark. The campaign of geospeleological investigations carried out in the 2007/2008/2009 years and most recently in 2022, 2023 and 2024 years, has concerned the karst area of the coastal belt of Benghazi, Sousa and the plateau of El-Marj, Al-Baydah, Dernah and Tobruk. In Benghazi area, the Lethe karst system with a large underground lake is of a particular interest. In the Sousa coastal area, a significant karst outcrop, was surveyed and documented, including Brak Notta karst system, which is constituted by a collapse doline and two large neighbouring doline-lake hydrologically connected by a recent tectonic structure. In the highly elevated areas of Al Baydah and Al Marj plateau, a very interesting geomorphologic and hydrogeologic studies show some large dolines and dip swallow-holes, inserted in the context of a typical cockpit relief, while in the plateau of Darnah the exploration of a complex labyrinthine cave has allowed the discovery of paleontologic and archaeological finds. Speleological/geological investigations of the above-mentioned karst areas are still being carried out in order to formulate a speleogenetic model linked to the tectonic phases and climatic changes that affected the Cyrenaica ridge during the Plio-Pleistocene to Recent.

Changes in Ecological–Production–Social Functions in Karst Areas: Insight from Guizhou Province, South China Karst

Changes in Ecological–Production–Social Functions in Karst Areas: Insight from Guizhou Province, South China Karst

Finite Element Analysis of the Excavation Stability of Deep and Large Ventilation Shafts of Zimuyan Tunnel Using the Raise Boring Machine Method in a Karst Area

Finite Element Analysis of the Excavation Stability of Deep and Large Ventilation Shafts of Zimuyan Tunnel Using the Raise Boring Machine Method in a Karst Area

Modified SWAT Model for Agricultural Watershed in Karst Area of Southwest China

The Soil and Water Assessment Tool (SWAT) model is extensively used globally for hydrological and water quality assessments but encounters challenges in karst regions due to their complex surface and groundwater hydrological environments. This study aims to refine the delineation of hydrological response units within the SWAT model by combining geomorphological classification and to enhance the model with an epikarst zone hydrological process module, exploring the accuracy improvement of SWAT model simulations in karst regions of Southwest China. Compared with the simulation results of the original SWAT model, we simulated runoff and nutrient concentrations in the Mudong watershed from January 2017 to December 2021 using the improved SWAT model. The simulation results indicated that the modified SWAT model responded more rapidly to precipitation events, particularly in bare karst landform, aligning more closely with the actual hydrological processes in Southwest China’s karst regions. In terms of the predictive accuracy for monthly loads of total nitrogen (TN) and total phosphorus (TP), the coefficient of determination (R2) value of the modified model increased by 10.3% and 9.7%, respectively, and the Nash–Sutcliffe efficiency coefficient (NSE) increased by 11.3% and 9.9%, respectively. The modified SWAT model improves prediction accuracy in karst areas and holds significant practical value for guiding non-point source pollution control in agricultural watersheds.

Relative forces of anthropogenic and natural factors on the evolution of "ecological cancer"-rocky desertification under different man-land relationships.

Rocky desertification (RD) is a severe phenomenon in karst areas, often referred to as "ecological cancer." However, studies on RD rarely include comparative analysis of different man-land relationship areas. This lack of analysis leads to difficulties in preventing and controlling RD in local areas with complex man-land relationships. To address this issue, we selected two typical karst areas, Guangnan County (with subtropical humid and agricultural peak-valley area) and Yulong County (with temperate semi-arid and ecological tourism alpine-canyon area), as comparative research areas. We analyzed the evolution of RD in these two typical areas and revealed the relative forces of anthropogenic and natural factors on RD at both a single and comprehensive level by using the geographical detector and the coupled principal component-structural equation model. The study found that (1) the RD in Yulong County was more severe than that in Guangnan County. From 2010 to 2020, RD in both counties showed a positive succession trends. The RD has a high degree of spatial fragmentation, and spatial evolution usually occurs in areas where the man-land relationship is complex. (2) In terms of single factor, the RD in the two counties was mainly affected by anthropogenic factors such as control, farming, behavioral disturbance, and social economy, and natural factors such as geology, soil, topography, and surface state. (3) Comprehensive effects show that forces of anthropogenic vs natural factors on formation/evolution of RD are different between Guangnan County (0.36 for anthropogenic factor vs -0.64 for natural factor) and Yulong County (higher with anthropogenic: 0.44 vs natural: 0.89). (4) Differentiated strategies should be adopted due to role played by anthropogenic and natural factors across different man-land relationship areas to explore suitable control measures for RD. The research creates a scientific basis for the control of RD, ecological restoration, and sustainable development in various regions. It can also be utilized as a valuable reference for comparative analysis of similar geographical phenomena.

Spatial characteristics of soil potassium in the early stage of vegetation restoration and influencing factors in southwest China’s karst region

The study established experimental transects in undisturbed areas of the Caohai Nature Reserve in Weining, Guizhou Province. The study aims to examine complete successional transects in different landscapes: non-karst, karst, and vegetation restoration, using the spatiotemporal substitution method. It analyzes the distribution patterns of Total potassium (TK) and Avail potassium (AK) in the soil and employs a Generalized Linear Mixed Model (GLMM) to investigate the effects of geomorphology, soil aggregates, and their interactions on the changes in soil potassium(K) elements. Furthermore, it explores the synergistic effects of K cycling during the vegetation restoration process in karst soils. The findings indicated that: (1) In karst areas, the overall TK content was higher than in non-karst areas, while the AK content in the topsoil was higher in non-karst areas. The TK content in the karst areas tended to approach that of the vegetation restoration zone. (2) After restoration, the dominant plants changed from Gramineae to Gramineae + Asteraceae, and the vegetation richness increased, thereby improving the soil fertility and potassium fixation capacity. (3) The GLMM showed that the karst landscape had a significant effect on the TK and AK contents of surface soil. In the early stage of vegetation restoration, the joint effect of soil and vegetation affected the TK and AK contents in soil.

Phylogenetic relationships of Smilax astrosperma (Smilacaceae) with other Smilax species and its potential distribution patterns in karst areas of south China

The genus Smilax is adapted for growth in karst areas of south China, likely because of the karst habitat heterogeneity of the area and climate factors. However, the phylogenetic relationships among different species in this genus and impact of environmental changes on its geographic distribution patterns remain unclear. Therefore, we assembled the 11 chloroplast genomes of the genus Smilax and reconstructed its phylogeny using the maximum‐likelihood method to confirm the phylogenetic relationships of Smilax astrosperma among 28 other Smilax genus species. In addition, a maximum entropy (MaxEnt) model was applied to evaluate and predict the potential distribution of S. astrosperma using bioclimatic variables, soil environment, elevation, slope degree and aspect, and human footprints under present and predicted future climate scenarios. The results show that S. astrosperma has a close relationship with S. glabra in the genus Smilax. The average temperature of the coldest quarter is a crucial factor influencing the distribution of S. astrosperma in karst areas. The potential distribution range of S. astrosperma increases and decreases under the SSP1‐2.6 and SSP5‐8.5 scenarios, respectively. These findings highlight that S. astrosperma and other species of the karst areas of south China need special attention under climate warming since both warming itself and extreme weather events threaten their survival.

Optimization of Development Strategies and Injection-Production Parameters in a Fractured-Vuggy Carbonate Reservoir by Considering the Effect of Karst Patterns: Taking C Oilfield in the Tarim Basin as an Example

The spatial structural characteristics of fractured-vuggy units vary greatly in different karst patterns, which significantly influence the study of remaining oil distribution patterns in ultra-deep fractured-vuggy reservoirs and the determination of the most efficient development strategies. However, few numerical simulation studies have focused on improving water and gas injection in fractured-vuggy reservoirs by considering the effect of karst patterns. By taking a typical fractured-vuggy reservoir in C oilfield in Tarim Basin, China as an example, the development dynamic characteristics of eight typical fractured-vuggy units in three different karst patterns are analyzed, and based on the newly proposed numerical simulation method of fluid vertical equilibrium, the residual oil reservoir distribution in different karst pattern fractured-vuggy units are studied, and the effects of fracture-vuggy karst patterns on the development characteristics, on the remaining oil morphology pattern, on the development strategies, and on the injection-production parameters are explored. This study shows that for different karst patterns fractured-vuggy units, the complexity of spatial structure, reserve scale, and oil-water relationship aggravates the heterogeneity of reservoirs and results in substantial differences in the development of dynamic patterns. In the northern facing karst fractured-vuggy units, there are two main types of remaining oil: well-spacing type and local-blocking type, and the reasonable development strategies are affected by reservoir morphology and the connectivity of structure patterns. Attic-type remaining oil mainly occurs in platform margin overlay and fault-controlled karst fractured-vuggy units. In the southern fault-controlled karst area, the remaining oil is mostly found along the upper part, and periodic gas injection or N2 huff-n-puff is recommended with priority for potential tapping. The fractured-vuggy karst patterns show a significant influence on the optimal level of injection-production parameters for improving the development of gas injection development strategies. The ideas of improving water injection and gas injection for fracture-vuggy reservoirs proposed in this paper also provide a good reference to further improve water control and increase oil production in other similar carbonate reservoirs.

Land carbon sink function variation across bedrock types in Southwest China.

Terrestrial ecosystem carbon sinks are a natural deposit that absorbs carbon from the atmosphere. A stable land carbon sink facilitates more reliable predictions of carbon sequestration under changing climate conditions. In contrast, a highly variable land carbon sink will introduce significant uncertainty into model predictions. Karst regions have attracted increasing attention due to their significant contribution to global land carbon sequestration capacity. However, understanding the stability of land carbon sinks and its driving factors in karst areas remains limited. This study focused on the world's largest karst zone, located in Southwest China (SWC), to assess the stability of land carbon sinks. By analyzing inter-annual variation (IAV) in net ecosystem productivity (NEP), we aimed to elucidate the spatial distribution of the stability of land carbon sinks and the dominant climatic drivers. We compared the stability of land carbon sinks across bedrocks, which were classified by carbonate content: non-karst, Discontinuous Carbonate Rocks (DCR), and Continuous Carbonate Rocks (CCR). Our findings showed that while land carbon sinks in karst bedrocks exhibited higher increased NEP rates than those in non-karst areas. Notably, we observed an inverse relationship between the rate and stability-regions with rapid land carbon sink enhancement were often characterized by instability, particularly in karst areas. Moreover, the drivers of the stability of land carbon sinks varied significantly between bedrock types. In non-karst regions, water availability was the primary factor influencing stability, whereas temperature was more dominant in karst regions. DCR regions showed lower stability due to the high sensitivity of land carbon sinks to temperature, while CCR regions experienced reduced stability linked to greater temperature variability. Our results highlight the need to consider the combined effects of bedrock type and climate factors on stability, offering valuable insights for managing and enhancing carbon sequestration capacity in a changing environment.

The Grain for Green Program Promotes Soil Organic Matter Accumulation and Improves Soil Fungal Diversity in the Southwestern Karst Region

Soil microorganisms play pivotal roles in terrestrial ecological processes. However, how soil microbial biomass and community characteristics respond to changes in land utilization in karst regions remains largely unknown. The present study investigated the impacts of land-use change on soil chemical properties, microbial community structure, and biomass in a karst region of southwest China across four land-use types: shrubland (natural vegetation restoration), plantation forest (managed vegetation restoration), orchards, and croplands. Vegetation restoration increased microbial biomass carbon and microbial biomass nitrogen. Shrubland had the highest bacterial and fungal abundance and fungal diversity; in addition, the soil microbial community structure differed significantly among land-use types. The dominant bacterial phyla were Actinobacteria, Proteobacteria, Acidobacteria, and Chloroflexi, whereas Ascomycota was the predominant fungal phylum, with its abundance declining significantly following vegetation restoration. Soil properties, including soil organic matter and available phosphorus, were strongly associated with microbial community composition and diversity in karst areas. The findings of this study are essential for gaining a deeper understanding of how changes in land-use affect soil properties and microbial dynamics, and provide valuable insights for ecological restoration and agricultural management in karst regions.

Five Years of Natural Vegetation Recovery in Three Forests of Karst Graben Area and Its Effects on Plant Diversity and Soil Properties

In recent decades, excessive human activities have led to large-scale rocky desertification in karst areas. Vegetation restoration is one of the most important ways to control rocky desertification. In this study, vegetation surveys were conducted on three typical plantations in Jianshui County, Yunnan Province, a typical karst fault basin area, in 2016 and 2021. The plantations were Pinus massoniana forest (PM), Pinus yunnanensis forest (PY), and mixed forests of Pinus yunnanensis and Quercus variabilis (MF). Plant diversity and soil nutrients were compared during the five-year period. This paper mainly draws the following results: The plant diversity of PM, PY, and MF increased. With the increase of time, new species appeared in the tree layer, shrub layer, and herb layer of the three forests. Tree species with smaller importance values gradually withdrew from the community. In the tree layer, the Patrick index, Simpson index, and Shannon–Wiener index of the three forests increased significantly. The Pielou index changed from the highest for PM in 2016 to the highest for PY in 2021. In the shrub layer, the Pielou index of the three forests increased. The Patrick index changed from the highest for MF in 2016 to the highest for PY in 2021. There was no significant difference in species diversity index for the herb layer. With the increase of vegetation restoration time, the soil bulk density (BD) of the three forests decreased. There was no significant difference in soil total porosity (TP), soil capillary porosity (CP), and non-capillary porosity (NCP). The pH of PM increased significantly from 5.88~6.24 to 7.24~7.34. The pH of PY decreased significantly (p < 0.05). The contents of total nitrogen (TN) and ammonium nitrogen (NH4+-N) in PY and MF decreased. The content of nitrate nitrogen (NO3−-N) in the three forests increased significantly (p < 0.05). Total phosphorus (TP) content decreased in PM and MF. The content of available phosphorus (AP) in PM and PY increased. In general, with the increase of vegetation restoration time, plant diversity and soil physical and chemical properties have also been significantly improved. The results can provide important data support for vegetation restoration in karst areas.

Soil Conservation Services and Its Enlightenment for Improving Ecosystems for Rocky Desertification Management: A Literature Review and Bibliometric Analysis

Soil conservation service (SC), as one of the most crucial ecosystem services (ES), plays a vital role in promoting the restoration of ecosystem structure. Severe soil erosion in karst areas has resulted in the ongoing degradation of soil conservation services. Understanding the current and evolution of research in this field is essential for establishing a theoretical foundation for the future management of rocky desertification in karst areas. Based on the Web of Science (WOS) and China Knowledge Network (CNKI) databases, 224 articles on SC were collected. This paper summarizes the research progress, results, and development trends from various aspects through systematic review and qualitative analysis of the literature. The findings are visually presented using spatial visualization and analysis tools such as SATI and Gephi. Key scientific issues and future development trends of existing SC are summarized with a view to improving SC in rocky desertification areas. It is of great significance to further improve the layout of ecological engineering construction and rocky desertification management in karst regions.

Comparative study of land capability and land suitability for pepper plants (Piper nigrum L.) on karst and non-karst area in Pacitan Regency

Karst areas are often major challenges for agricultural development. Punung District in Pacitan Regency is included in the Gunung Sewu Karst Area, a UNESCO heritage geopark. Even as a center for pepper production, the production continues to decline. This study aims to determine the capability and suitability of land for pepper plants in the karst and non-karst areas of Punung District. This study is a field survey with purposive random sampling. The sampling points are based on the overlay of soil type, geology, and rainfall maps. The data variability of soil characteristics from the sampling was analyzed using ANOVA and resulted in a Land Map Unit (LMU). Data from the LMU were analyzed by matching the criteria for capability and land suitability with the results of observations. The results showed that the land capability of the karst and non-karst areas is the same class as II, III, and IV with limiting factors of surface, erosion rate, and soil depth. Land suitability for pepper is also the same, as marginal suitability (S3) with the limiting factors being the availability of water, very low available P nutrients, and the rate of erosion. The impact of this study is the Karst and non-karst do not significantly effect the class of land capability and land suitability for pepper plant development in this study area.

Management of surface and spring water for rice cultivation as climate adaptation in dry land

Dry land is characterized by the main problem of water shortage. In karst areas, this problem can be reduced by the presence of springs. This research aims to examine the use of rainfall, surface flow and spring water to support rice planting in the second growing season as a form of adaptation to climatic conditions of dry land in karst areas. The research was carried out on dry land in the Gunungsewu karst area, Gunungkidul D.I. Yogyakarta Indonesia. The research used observation methods, farmer interviews and rice planting trials. The research results show that farmers have managed rainfall, surface flow and spring water for agricultural and household. Utilization of water resources for rice cultivation in the second growing season produced of 6.800 ton ha-1, with income of IDR23,290,000 ha-1. Additional results in the form of straw biomass amounted of 7.232 ton ha-1. Rice requires a lot of water, so water management must based on the soil and water conservation principles, to be sustainable.

Analysis of the distribution and the impact of drought on agricultural land in Sekotong District, West Lombok

The existence of the El Nino phenomenon has an environmental impact, it causes low rainfall in the southern hemisphere, like Indonesia. Drought caused by El Nino is distributed throughout Indonesia, including Lombok Island. Sekotong District has an area surrounded by karst landforms and beaches. Karst areas cannot store groundwater so droughts often occur. Low rainfall and low water availability cause agricultural land to dry out so it cannot fill agricultural needs. This study aims to map the distribution of land affected by drought due to El Nino and its impact on agriculture in Sekotong District. The analysis of this study uses the Normalized Difference Drought Index (NDDI) analysis for the distribution of land drought and by conducting purposive interviews with farmers in Sekotong District. The results are the area of land drought class of around 2754.81 hectares without water shortage; 11,727.46 hectares in normal conditions; 11,715.31 hectares mild drought; 5313.1 hectares moderate drought; 1,606.62 hectares severe drought; and 1,144.57 hectares very severe drought. The impacts of this land drought include 1) Crop failure in rice commodities; 2) Agricultural land crops are substituted with peanuts and corn; 3) Agricultural land is not utilized at all because there is no water available.