Karst Environment and Global Change

Abstract submission deadline

28 January 2025

Manuscript submission deadline

28 March 2025

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Topic Information

Dear Colleagues,

Karst areas are some of the world’s major ecologically fragile zones, accounting for 12% of the global land area and affecting the productive lives of 1.8 billion people. In particular, the East Asian karst region, centered on the Guizhou Plateau, is the largest and most concentrated contiguous ecologically fragile area in the world, covering an area of over 550,000 square kilometers, and is also the one with the most typical and complex karst development as well as the richest landscape types. The special ecological environment has multifaceted effects on natural, economic, and social development: on the one hand, karst regions are rich in mineral and medicinal resources; on the other, due to the special karst geological background, coupled with the increasingly harsh human–land conflict relationship, they are increasingly affected by the interaction of multiple layers from the lithosphere, atmosphere, hydrosphere, and biosphere. As a result, ecological problems, such as rock desertification, heavy metal pollution, diminishing biodiversity, and the irrational exploitation of mineral as well as medicinal resources, have emerged. At the same time, the Earth has experienced dramatic climate change in recent years, which may have a significant impact on karst ecological patterns, service functions, and sustainable development. However, uncertainties remain about the variability of karst environments and how they will respond to global change. Therefore, the aim of this topic is to discuss cutting-edge and hot issues, new techniques and methods, and new findings in this field on the topic of karst environments and global change, including various formats such as reviews, research papers, and datasets; contributions from experts and scholars in related fields are also welcome. Original research articles and reviews are welcome. Research areas may include (but are not limited to) the following:

• Karst ecosystem assessment (including stone desertification, soil erosion, soil formation rates, etc.);
• Carbon cycling, storage, and sinks in karst ecosystems;
• Biodiversity, ecosystem processes, ecosystem services, and climate change;
• Spatial and temporal dynamics of vegetation (productivity, greenness, vegetation cover, leaf area index, phenology, etc.) in response to climate change and human activities;
• Carbon sequestration, carbon emissions, carbon efficiency, and low-carbon mitigation policies in karst ecosystems.

Prof. Dr. Xiaoyong Bai
Prof. Dr. Yongjun Jiang
Prof. Dr. Jian Ni
Prof. Dr. Xubo Gao
Prof. Dr. Yuemin Yue
Prof. Dr. Jiangbo Gao
Dr. Junbing Pu
Dr. Hu Ding
Dr. Qiong Xiao
Prof. Dr. Zhicai Zhang
Topic Editors

Keywords

Participating Journals

Journal Name	Impact Factor	CiteScore	Launched Year	First Decision (median)	APC
Atmosphere atmosphere	2.5	4.6	2010	15.8 Days	CHF 2400	Submit
Forests forests	2.4	4.4	2010	16.9 Days	CHF 2600	Submit
Hydrology hydrology	3.1	4.9	2014	18.6 Days	CHF 1800	Submit
Land land	3.2	4.9	2012	17.8 Days	CHF 2600	Submit
Remote Sensing remotesensing	4.2	8.3	2009	24.7 Days	CHF 2700	Submit
Geosciences geosciences	2.4	5.3	2011	26.2 Days	CHF 1800	Submit
Sustainability sustainability	3.3	6.8	2009	20 Days	CHF 2400	Submit

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Published Papers (13 papers)

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25 pages, 9871 KiB  

Open AccessArticle

Investigating the Morphometry and Hydrometeorological Variability of a Fragile Tropical Karstic Lake of the Yucatán Peninsula: Bacalar Lagoon

by Laura Carrillo, Mario Yescas, Mario Oscar Nieto-Oropeza, Manuel Elías-Gutiérrez, Juan C. Alcérreca-Huerta, Emilio Palacios-Hernández and Oscar F. Reyes-Mendoza

Hydrology 2024, 11(5), 68; https://doi.org/10.3390/hydrology11050068 - 11 May 2024

Cited by 1 | Viewed by 1767

Abstract

Comprehensive morphometric and hydrometeorological studies on Bacalar Lagoon, Mexico’s largest tropical karstic lake and a significant aquatic system of the Yucatán Peninsula, are lacking. This study provides a detailed analysis of its bathymetry, morphometry, and hydrometeorological characteristics. The lake’s main basin stretches more [...] Read more.

Comprehensive morphometric and hydrometeorological studies on Bacalar Lagoon, Mexico’s largest tropical karstic lake and a significant aquatic system of the Yucatán Peninsula, are lacking. This study provides a detailed analysis of its bathymetry, morphometry, and hydrometeorological characteristics. The lake’s main basin stretches more than 52.7 km in length, with widths varying from 0.18 km to 2.28 km. It has a volume of 554.4 million cubic meters, with an average depth of 8.85 m, reaching depths of up to 26 m in the north and featuring sub-lacustrine dolines in the south, with depths of 38 m, 48.5 m, and 63.6 m. The study reveals seasonal variations in surface water temperature, closely linked to air temperature (r = 0.89), and immediate responses of water levels to hydrometeorological events. Water level fluctuations also exhibit seasonal patterns that are correlated with regional aquifer conditions, with a lag of 2 months after seasonal rainfall. Interannual variability in rainfall and water levels was observed. From 2010 to 2012, rainfall consistently remained below its mean climatic value, due to a prolonged La Niña event, while the exceptionally wet conditions in 2020 were also associated with La Niña. Extreme and anomalous hydrometeorological events, such as those following tropical storm Cristobal in 2020, revealed the fragility of Bacalar Lagoon, causing a notable transformation in lake color and transparency, shifting it from its typical oligotrophic state to eutrophic conditions that lasted longer than a year. These color changes raise questions about the factors impacting ecological health in tropical karstic regions. Additional factors affecting water quality in the BL in 2020, such as deforestation, coastline changes, and urban growth, warrant further investigation. Our study can serve as a starting landmark. Full article

(This article belongs to the Topic Karst Environment and Global Change)

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18 pages, 4956 KiB  

Open AccessArticle

Spatial-Temporal Heterogeneity of Ecosystem Service Value Driven by Nature-Human Activity-Policy in a Representative Fragile Karst Trough Valley, SW China

by Cheng Zeng, Gaoning Zhang, Tianyang Li, Binghui He and Dengyu Zhang

Land 2024, 13(2), 256; https://doi.org/10.3390/land13020256 - 19 Feb 2024

Viewed by 1115

Abstract

Most studies on the ecosystem service value (ESV) only focus on spatial/temporal heterogeneity or single driving effects, but little is known about the combined effects of nature-human activity-policy on ESV in the fragile karst areas. This study aimed to investigate the spatial-temporal heterogeneity [...] Read more.

Most studies on the ecosystem service value (ESV) only focus on spatial/temporal heterogeneity or single driving effects, but little is known about the combined effects of nature-human activity-policy on ESV in the fragile karst areas. This study aimed to investigate the spatial-temporal heterogeneity of ESV between 1990 and 2020 in a representative karst trough valley in SW China. The dynamic degree of land use, the land-use transfer matrix, sensitive analyses, Geo-Detector, and Hot- and cold-spots analyses were used to determine the interactions between ESV and the natural, human activity, and policy-driving factors. The results showed that from 1990 to 2020, forestland accounted for more than 62.32% of the total area, and construction land increased continuously as a result of urbanization. The conversion from forestland to cropland dominated the land-use transfer. The ESV decreased sharply between 1990 and 2000 and slowly increased from 2000 to 2020, causing a total reduction of 562.91 million yuan in ESV, due largely to the occupation of forestland and grassland by cropland. Soil type (8.00%) had the largest explanation rate for the spatial-temporal heterogeneity of ESV, followed by population density (7.71%) and altitude (6.34%). Policy factors not only markedly influenced the ecosystem structure and function and tradeoff and synergy but also regulated their interactions with other driving factors. Our results have great significance for understanding the interaction effect of natural sources and human activities on changes in ESV in karst areas. Full article

(This article belongs to the Topic Karst Environment and Global Change)

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20 pages, 11531 KiB  

Open AccessFeature PaperArticle

Urban Vegetation Classification for Unmanned Aerial Vehicle Remote Sensing Combining Feature Engineering and Improved DeepLabV3+

by Qianyang Cao, Man Li, Guangbin Yang, Qian Tao, Yaopei Luo, Renru Wang and Panfang Chen

Forests 2024, 15(2), 382; https://doi.org/10.3390/f15020382 - 18 Feb 2024

Cited by 2 | Viewed by 1578

Abstract

Addressing the problems of misclassification and omissions in urban vegetation fine classification from current remote sensing classification methods, this research proposes an intelligent urban vegetation classification method that combines feature engineering and improved DeepLabV3+ based on unmanned aerial vehicle visible spectrum images. The [...] Read more.

Addressing the problems of misclassification and omissions in urban vegetation fine classification from current remote sensing classification methods, this research proposes an intelligent urban vegetation classification method that combines feature engineering and improved DeepLabV3+ based on unmanned aerial vehicle visible spectrum images. The method constructs feature engineering under the ReliefF algorithm to increase the number of features in the samples, enabling the deep learning model to learn more detailed information about the vegetation. Moreover, the method improves the classical DeepLabV3+ network structure based on (1) replacing the backbone network using MoblieNetV2; (2) adjusting the atrous spatial pyramid pooling null rate; and (3) adding the attention mechanism and the convolutional block attention module. Experiments were conducted with self-constructed sample datasets, where the method was compared and analyzed with a fully convolutional network (FCN) and U-Net and ShuffleNetV2 networks; the migration of the method was tested as well. The results show that the method in this paper is better than FCN, U-Net, and ShuffleNetV2, and reaches 92.27%, 91.48%, and 85.63% on the accuracy evaluation indices of overall accuracy, MarcoF1, and mean intersection over union, respectively. Furthermore, the segmentation results are accurate and complete, which effectively alleviates misclassifications and omissions of urban vegetation; moreover, it has a certain migration ability that can quickly and accurately classify the vegetation. Full article

(This article belongs to the Topic Karst Environment and Global Change)

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16 pages, 12452 KiB  

Open AccessArticle

Carbon Sink Trends in the Karst Regions of Southwest China: Impacts of Ecological Restoration and Climate Change

by Xiaojuan Xu, Fusheng Jiao, Dayi Lin, Jing Liu, Kun Zhang, Ruozhu Yang, Naifeng Lin and Changxin Zou

Land 2023, 12(10), 1906; https://doi.org/10.3390/land12101906 - 10 Oct 2023

Cited by 3 | Viewed by 1870

Abstract

Southwest China (SWC) holds the distinction of being the world’s largest rock desertification area. Nevertheless, the impacts of climate change and ecological restoration projects on the carbon sinks in the karst area of Southwest China have not been systematically evaluated. In this study, [...] Read more.

Southwest China (SWC) holds the distinction of being the world’s largest rock desertification area. Nevertheless, the impacts of climate change and ecological restoration projects on the carbon sinks in the karst area of Southwest China have not been systematically evaluated. In this study, we calculated carbon sinks by utilizing the Carnegie–Ames–Stanford Approach (CASA) model, and the actual measurements, including the net primary productivity (NPP) data and soil respiration (Rs,) were calculated to obtain carbon sink data. Our findings suggest that the carbon sinks in the karst areas are displaying increasing trends or positive reversals, accounting for 58.47% of the area, which is larger than the overall average of 45.08% for Southwest China. This suggests that the karst areas have a greater carbon sequestration potential. However, approximately 10.42% of carbon sinks experience negative reversals. The regions with increasing and positive reversals are primarily located in the western parts of Guizhou and Guangxi, while negative reversals are observed in the eastern parts of Chongqing, Guangxi, and Guizhou. Ecological restoration projects are the main driving factors for the carbon sinks with increasing trends. Increased humidity and ecological restoration management are the main reasons for the positive reversals of carbon sinks. However, warming and drought shift the carbon sinks from increasing to decreasing in Chongqing, east of Guangxi and Guizhou. The findings of this study highlight the significant role of ecological restoration projects and reexamine the impact of climate change on carbon sequestration. Full article

(This article belongs to the Topic Karst Environment and Global Change)

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18 pages, 4724 KiB  

Open AccessArticle

Multidimensional Valuation and Spatial Differentiation of Cultivated Land Resources at the County Scale: A Case Study of Guangxi, China

by Zhantu Chen, Li Ren, Ling Xie and Qiong Xiao

Land 2023, 12(10), 1904; https://doi.org/10.3390/land12101904 - 10 Oct 2023

Cited by 1 | Viewed by 1290

Abstract

Revealing the multidimensional value of cultivated land resources, improving calculation methods, and exploring their spatial distribution characteristics and influencing factors are crucial for the enhancement of natural resource accounting systems and the protection of cultivated land resources. This study takes Guangxi, China, as [...] Read more.

Revealing the multidimensional value of cultivated land resources, improving calculation methods, and exploring their spatial distribution characteristics and influencing factors are crucial for the enhancement of natural resource accounting systems and the protection of cultivated land resources. This study takes Guangxi, China, as an example and constructs a comprehensive multidimensional value evaluation system for cultivated land resources at the county scale. The income capitalization method, substitution market method, and value equivalent correction method were applied to calculate the economic, social, and ecological values of cultivated land resources in 111 counties in 2020. Furthermore, spatial autocorrelation analysis was employed to study their distribution characteristics and influencing factors. The results show that: (1) In 2020, the total value of cultivated land resources in Guangxi was USD 2859.3 billion, with the economic, social, and ecological values were USD 1674.2 billion, USD 417.7 billion and USD 767.3 billion USD, respectively. (2) The economic and social value of cultivated land per hectare at the county scale in Guangxi demonstrates similar spatial distribution patterns. High-value counties exhibit a strip-like distribution along the eastern edge, following a north–south orientation, while low-value counties form clusters in the central and western regions. (3) There is a significant spatial clustering effect of all values of cultivated land resources in local space, with “high-high” and “low-low” clustering. (4) The level of economic development in counties has a negative impact on the ecological value of cultivated land resources, while it has a positive impact on their social value. (5) Natural conditions, agricultural infrastructure conditions and agricultural development approaches are the key factors affecting the value of cultivated land resources. Full article

(This article belongs to the Topic Karst Environment and Global Change)

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15 pages, 18239 KiB  

Open AccessArticle

Estimating Forest Aboveground Biomass Combining Pléiades Satellite Imagery and Field Inventory Data in the Peak–Cluster Karst Region of Southwestern China

by Yinming Guo, Meiping Zhu, Yangyang Wu, Jian Ni, Libin Liu and Yue Xu

Forests 2023, 14(9), 1760; https://doi.org/10.3390/f14091760 - 30 Aug 2023

Cited by 3 | Viewed by 1424

Abstract

The mountainous region of southwest China has the largest karst geomorphology in China and in the world. Quantifying the forest aboveground biomass in this karst region is of great significance for the investigation of carbon storage and carbon cycling in terrestrial ecosystems. In [...] Read more.

The mountainous region of southwest China has the largest karst geomorphology in China and in the world. Quantifying the forest aboveground biomass in this karst region is of great significance for the investigation of carbon storage and carbon cycling in terrestrial ecosystems. In this study, the actual measured aboveground biomass was calculated based on the allometric functions of 106 quadrats from 2012 to 2015. A backpropagation artificial neural network (BPANN) inversion model was constructed by combining very high-resolution satellite imagery, field inventory data, and land use/land cover data to estimate the forest aboveground biomass in the Banzhai watershed, a typical peak–cluster karst basin in southern Guizhou Province. We used 70% of the actual measured aboveground biomass for training the BPANN model, 20% for accuracy verification, and 10% to prevent overtraining. The results show that the absolute root mean square error of the BPANN model was 11.80 t/ha, which accounted for 9.92% of the mean value of aboveground biomass. Based on the BPANN inversion model, the average value of the forests’ aboveground biomass was 135.63 t/ha. The results showed that our study presented a quick, easy, and relatively high-precision method for estimating forest aboveground biomass in the Banzhai watershed. This indicates that the Pléiades image-based BPANN model displayed satisfactory results for estimating the forests’ aboveground biomass in a typical peak–cluster karst basin. This method can be applied to the estimation of forest AGB in the karst mountainous areas of southwest China. Full article

(This article belongs to the Topic Karst Environment and Global Change)

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21 pages, 10217 KiB  

Open AccessArticle

Spatiotemporal Variations in the Carbon Sequestration Capacity of Plateau Lake Wetlands Regulated by Land Use Control under Policy Guidance

by Bo Chen, Meiqi Zhang, Rui Yang and Wenling Tang

Land 2023, 12(9), 1695; https://doi.org/10.3390/land12091695 - 29 Aug 2023

Cited by 3 | Viewed by 1410

Abstract

Lake wetlands play a crucial role in mitigating climate change. Human activities and climate change impact the carbon sequestration capacity of lake wetlands. However, this process is intricate. Clarifying the decisive factors that affect carbon sequestration is crucial for preserving, utilizing, and enhancing [...] Read more.

Lake wetlands play a crucial role in mitigating climate change. Human activities and climate change impact the carbon sequestration capacity of lake wetlands. However, this process is intricate. Clarifying the decisive factors that affect carbon sequestration is crucial for preserving, utilizing, and enhancing the carbon sequestration capacity of plateau lake wetlands. Here we analyzed the regulatory role of land use under policy guidance on the carbon sequestration capacity of the plateau lake wetland of Caohai (CHLW), SW China. The results show that: (1) The cumulative carbon sequestration varied significantly from 1990 to 2020, with the highest carbon sequestration of 15.80 × 10⁵ t C in 1995 and the lowest of 3.18 × 10⁵ t C in 2020, mainly originating from endogenous carbon sequestration within the plateau lake wetlands. (2) As of 2020, the carbon stock of CHLW was approximately 2.54 × 10⁸ t C. (3) The carbon sequestration in CHLW experienced a dynamic change process of decrease-increase-decrease over 30 years, mainly influenced by land use changes under policy regulation, with human and natural factors accounting for 91% and 9%, respectively. (4) Under three simulated scenarios (Q1, Q2, and Q3), the ecological priority scenario exhibited positive regulation on the carbon sequestration of CHLW and the entire protected area in 2030 and 2060, with the highest increase in carbon sequestration. This scenario is consistent with the current conservation policy, indicating that the current protection policy for CHLW is scientifically reasonable. This research demonstrates how land use and climate changes impact carbon storage in wetlands, with consideration of policy guidance. It provides references for utilizing and conserving lake wetlands worldwide, ultimately achieving the dual goals of wetland conservation and carbon neutrality. Full article

(This article belongs to the Topic Karst Environment and Global Change)

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17 pages, 9008 KiB  

Open AccessReview

Response of the Desertification Landscape Patterns to Spatial–Temporal Changes of Land Use: A Case Study of Salaxi in South China Karst

by Tian Shu, Kangning Xiong and Ning Zhang

Land 2023, 12(8), 1557; https://doi.org/10.3390/land12081557 - 5 Aug 2023

Cited by 6 | Viewed by 1729

Abstract

Land use change and karst desertification (KD) are interdependent. It is crucial to investigate the relationship between the KD landscape and spatial–temporal changes in land use for effective and sustainable KD management practices in karst plateau mountains. In this study, we analyzed the [...] Read more.

Land use change and karst desertification (KD) are interdependent. It is crucial to investigate the relationship between the KD landscape and spatial–temporal changes in land use for effective and sustainable KD management practices in karst plateau mountains. In this study, we analyzed the spatial and temporal characteristics, evolution in the pattern of land use, and KD in the Salaxi study area from 2009 to 2019, using the landscape pattern index and KD evolution trajectories, and discussed their response relationships. The results revealed the following: (1) In Salaxi, cultivated land predominantly transformed into shrubland, grassland, and woodland. The area of grassland, construction land, and garden land significantly increased, with respective increments of 379.85%, 157.14%, and 1847.81%. Conversely, the area of unutilized land decreased from 53.56 hm² to 8.55 hm², with the proportion declining from 0.62% to 0.10%. KD primarily occurs in shrubland, cultivated land, and woodland. (2) The areas of non-KD and potential KD have increased. There was a noticeable conversion of light and medium KD into potential KD, with areas of 1206.84 hm² and 459.47 hm², respectively. The KD landscape is dominated by stable and weakening ecological restoration. The comprehensive ranking of the incidence of soil KD in the study area is as follows: yellow soil > yellow-brown soil > coarse bone soil > limestone soil > purple soil. (3) The land use landscape index, the evenness index, and the fragmentation index in the demonstration area increased by 0.263, 0.120, and 0.534, respectively, while the KD landscape index, evenness index, and fragmentation index decreased by 0.360, 0.123, and 1.098, respectively. Additionally, the spreading index and aggregation index of the land use landscape decreased by 9.247 and 3.086, respectively, while the KD landscape’s spreading index and aggregation index increased by 6.688 and 0.430, respectively. Both the sub-dimension indexes of the land use landscape and the KD landscape increased by 0.009. Overall, the landscape pattern of KD changes in response to land use variations and different land types exhibited varying responses to KD. The study of KD and land use landscape patterns can provide references for national strategies on KD control and the development of ecological industries. Full article

(This article belongs to the Topic Karst Environment and Global Change)

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27 pages, 42107 KiB  

Open AccessArticle

Temperature Evolution of Cooling Zones on Global Land Surface since the 1900s

by Luhua Wu, Xiaoyong Bai, Yichao Tian, Yue Li, Guangjie Luo, Jinfeng Wang and Fei Chen

Atmosphere 2023, 14(7), 1156; https://doi.org/10.3390/atmos14071156 - 16 Jul 2023

Cited by 4 | Viewed by 1758

Abstract

The existence of global warming is common knowledge. However, it can be predicted that there may be cooling zones worldwide based on the mechanism of terrestrial biophysical processes. Here, the Theil–Sen median trend, the Mann–Kendall trend test method, continuous wavelet transformation, and the [...] Read more.

The existence of global warming is common knowledge. However, it can be predicted that there may be cooling zones worldwide based on the mechanism of terrestrial biophysical processes. Here, the Theil–Sen median trend, the Mann–Kendall trend test method, continuous wavelet transformation, and the Hurst exponent were used to study the cooling trends, abrupt change times, periodicity, and future sustainability of temperature changes in different cooling zones since the 1900s based on the CRU dataset. We found an amazing result; 8,305,500 km² of land surface had been cooling since the 1900s, covering five continents and 32 countries, accounting for 86% of land area in China, and distributed over 16 zones. The average cooling rate of the cooling zones was −0.24 °C/century. The maximum cooling rate was −1.40 °C/century, and it was 1.43 times the average rate of global land warming (0.98 °C/century). The cooling zones near the sea were greatly influenced by ocean currents and were mainly affected by a small time scale periodicity of less than 30 years, whereas the cold zones located relatively far from the sea and less affected by ocean currents were mainly affected by medium time scales of more than 30 years. Moreover, 32.33% of the cooling zones, involving 2,684,900 km^2, will be continuously cooling in the future, and the rest will probably warm up in 2114, 2041, 2096, 2099, 2119, 2073, 2048, and 2101, respectively. The study will help us to further understand the essential characteristics of global climate change, and to find more theoretical bases for mitigating global warming and exploring surface cooling mechanisms. Full article

(This article belongs to the Topic Karst Environment and Global Change)

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18 pages, 5225 KiB  

Open AccessArticle

Vertical Divergence Characteristics of Dissolved Inorganic Carbon and Influencing Factors in a Karst Deep-Water Reservoir, Southwest China

by Zhongfa Zhou, Cui Wang, Yongliu Li, Yongrong Zhang and Jie Kong

Atmosphere 2023, 14(7), 1111; https://doi.org/10.3390/atmos14071111 - 4 Jul 2023

Cited by 2 | Viewed by 1102

Abstract

In deep karst reservoirs, the internal environment is complex, and thermal stratification isnot the only factor controlling the vertical distribution of the DIC concentration. Previous studies have not fully understood the migration and transformation of DIC in a deep-water reservoir. In this study, [...] Read more.

In deep karst reservoirs, the internal environment is complex, and thermal stratification isnot the only factor controlling the vertical distribution of the DIC concentration. Previous studies have not fully understood the migration and transformation of DIC in a deep-water reservoir. In this study, a deep-water reservoir in southwest China was chosen, and the spatial and temporal characteristics of the DIC concentration, pCO₂, δ¹³C_DIC value, and SIc were investigated. It was found that the Pingzhai Reservoir is a double temperature leapfrog reservoir. The DIC concentration, pCO₂, Sic, and δ¹³C_DICvalues showed annual cycle variation. During the thermal stratification phase, the DIC concentration, pCO₂, Sic, and δ¹³C_DICvalues were significantly different between the surface layer and the lower layer. However, during the mixing and mixed phases, the differences were not significant. The vertical divergence of the DIC in the Pingzhai Reservoir was influenced by the subtemperate layer, human activities, and sources. The formation of the subtemperate layer was due to the submerged flow formed when river water enteredthe reservoir, which provides a channel for DIC from the river to enter the lower layer of the reservoir. Human activities increased the solubility of carbonate rocks in the reservoir, and the source of DIC was one of the factors contributing to the concentration stratification of DIC in the reservoir. Full article

(This article belongs to the Topic Karst Environment and Global Change)

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19 pages, 11672 KiB  

Open AccessArticle

Spatiotemporal Transfer of Source-Sink Landscape Ecological Risk in a Karst Lake Watershed Based on Sub-Watersheds

by Zhongfa Zhou, Weiquan Zhao, Sisi Lv, Denghong Huang, Zulun Zhao and Yaopeng Sun

Land 2023, 12(7), 1330; https://doi.org/10.3390/land12071330 - 1 Jul 2023

Cited by 4 | Viewed by 1379

Abstract

Non-point source pollution is an important source of ecological risk in karst lakes. The process of source–sink landscapes is the main pathway of pollution migration and plays an important role in water quality. In this study, the ecological risk evolution in the past [...] Read more.

Non-point source pollution is an important source of ecological risk in karst lakes. The process of source–sink landscapes is the main pathway of pollution migration and plays an important role in water quality. In this study, the ecological risk evolution in the past 30 years was studied in a karst lake watershed with 495 sub-basins as the basic evaluation unit, and the risk assessment model of non-point source pollution was improved by using rainfall and fertilizer application. The results show that (1) the area of cultivated land shrank significantly, with forest land and construction land showing an upward trend in general; (2) the layout of the sink landscape continuously shrank, while the source landscape gradually expanded, and the space of high load values further increased and shifted from a flower-like layout distribution to concentrated contiguity, with some values exceeding 0.5; (3) the 252 sub-watersheds of the sink landscape migrated from very low risk to low risk, while the risk of the source landscape changed from medium risk to high and very high risk in 48 sub-watersheds; and (4) in terms of the overall trend of ecological risk transformation of the source–sink landscape, the transformation of sink landscapes to source landscapes was greater than that of source landscapes to sink landscapes, and the overall ecological risk showed an increasing trend. Full article

(This article belongs to the Topic Karst Environment and Global Change)

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20 pages, 17672 KiB  

Open AccessArticle

A Comparative Study on Land Use/Land Cover Change and Topographic Gradient Effect between Mountains and Flatlands of Southwest China

by Li Wu, Yanjun Yang, Hailan Yang, Binggeng Xie and Weiqun Luo

Land 2023, 12(6), 1242; https://doi.org/10.3390/land12061242 - 17 Jun 2023

Cited by 3 | Viewed by 1940

Abstract

Topography plays an important role in restricting the formation of and change in land use/land cover (LULC) patterns. To compare the LULC change and topographic gradient effects between mountains and flatlands, the geo-informatic atlas, terrain position index, distribution index and diversity index were [...] Read more.

Topography plays an important role in restricting the formation of and change in land use/land cover (LULC) patterns. To compare the LULC change and topographic gradient effects between mountains and flatlands, the geo-informatic atlas, terrain position index, distribution index and diversity index were used to analyze the LULC patterns in Yuxi from 2000 to 2020. The results were as follows: (1) the temporal–spatial variation in LULC was obviously different. From 2000 to 2020, land use change in the flatlands was more severe than that in the mountains. The transfer amount of forestland in the mountains was the largest, with the transfer-out and transfer-in accounting for 48.53% and 31.05%. However, in the flatlands, the biggest changes were found in the transfer-out of cultivated land and the transfer-in of build-up land, which were 46.91% and 38.20%, respectively. The LULC types in the mountains changed dramatically from 2000 to 2010, while those in the flatlands changed dramatically from 2010 to 2020. (2) There were obvious differences in the topographic gradient effects. The dominant distributions of land use types in the low-terrain area were the same, but the dominance of build-up land in the flatlands and that of wetland in the mountains were the largest. In the mountains, the dominant distribution of grassland was in the medium-terrain position, while that of forestland was in the high position, and the opposite was found in the flatlands. In addition, the variation trend of the diversity index in the mountains was relatively simple, but the variation range was large, ranging from 0 to 1.677, and high diversity was mainly found in the medium- and high-terrain positions. However, the variation trend in the flatlands was complex, but only ranged from 0.918 to 1.994, and high diversity was found in the low-terrain positions. The differences in the LULC change and terrain gradient effects between the mountains and flatlands were mainly caused by natural, socio-economic and policy factors, which can provide a certain reference for differentiated land use policies for regional coordinated and sustainable development. Full article

(This article belongs to the Topic Karst Environment and Global Change)

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20 pages, 13403 KiB  

Open AccessArticle

Response of Runoff Change to Extreme Climate Evolution in a Typical Watershed of Karst Trough Valley, SW China

by Luhua Wu, Dan Chen, Dongni Yang, Guangjie Luo, Jinfeng Wang and Fei Chen

Atmosphere 2023, 14(6), 927; https://doi.org/10.3390/atmos14060927 - 25 May 2023

Cited by 7 | Viewed by 2024

Abstract

Identifying the response of runoff changes to extreme climate evolution was of great scientific significance for the rational regulation of watershed water resources and the prevention of hydrological disasters. However, the time–frequency response relationships were not clear. The Yinjiang River watershed, a typical [...] Read more.

Identifying the response of runoff changes to extreme climate evolution was of great scientific significance for the rational regulation of watershed water resources and the prevention of hydrological disasters. However, the time–frequency response relationships were not clear. The Yinjiang River watershed, a typical watershed with karst trough valley areas, was chosen to identify the impact of different climatic driving factors on runoff changes from 1984 to 2015. Continuous wavelet transform (CWT), cross-wavelet transform (XWT), and wavelet coherence transform (WTC) were performed to study the response relationship and time–frequency effect between runoff changes and extreme climate change at different time scales. The main results showed that: (1) Twelve extreme climate indices (ECIs) were detected to have a significant impact on runoff changes, mainly on a 6-year time scale; (2) The R10 and Rx1day in extreme precipitation index and SU34.4 and TNx in the extreme temperature index were the main driving factors of runoff changes, which had relatively large impacts on runoff changes in high and low energy vibration regions. However, the remaining eight ECIs that passed the 0.05 confidence level showed relatively large impacts on runoff changes only in low energy vibration regions; (3) The transition of the interaction between ECIs and runoff changes in high and low time–frequency scales was related to the abrupt change characteristics of the ECIs. The correlation of abrupt change was an important reason for the emergence of highly correlated regions that trigger high and low energy vibrations; (4) As a whole, the extreme precipitation events were ahead of runoff changes at the high time–frequency scale and exhibited small lag effects at the low time–frequency scale, while extreme temperature events were mainly ahead of runoff changes. This study has effectively revealed the impact of climate factors at different scales on runoff changes, and provides a theoretical understanding for regulating and managing water resources in karst basins. Full article

(This article belongs to the Topic Karst Environment and Global Change)

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