ABSTRACT
China is experiencing large-scale rural-urban migration and rapid urbanization, which have had significant impact on terrestrial carbon sink. However, the impact of rural-urban migration and its accompanying urban expansion on the carbon sink is unclear. Based on multisource remote sensing product data for 2000-2020, the soil microbial respiration equation, relative contribution rate, and threshold analysis, we explored the impact of rural depopulation on the carbon sink and its threshold. The results revealed that the proportion of the rural population in China decreased from 63.91 % in 2000 to 36.11 % in 2020. Human pressure decreased by 1.82% in rural depopulation areas, which promoted vegetation restoration in rural areas (+8.45 %) and increased the carbon sink capacity. The net primary productivity (NPP) and net ecosystem productivity (NEP) of the vegetation in the rural areas increased at rates of 2.95 g C m-2 yr-1 and 2.44 g C m-2 yr-1. Strong rural depopulation enhanced the carbon sequestration potential, and the NEP was 1.5 times higher in areas with sharp rural depopulation than in areas with mild rural depopulation. In addition, the rural depopulation was accompanied by urban expansion, and there was a positive correlation between the comprehensive urbanization level (CUL) and NEP in 75.29 % of urban areas. In the urban areas, the vegetation index increased by 88.42 %, and the urban green space partially compensated for the loss of carbon sink caused by urban expansion, with a growth rate of 4.96 g C m-2 yr-1. Changes in rural population have a nonlinear impact on the NEP. When the rural population exceeds 545.686 people/km2, an increase in the rural population will have a positive impact on the NEP. Our research shows that rural depopulation offers a potential opportunity to restore natural ecosystems and thus increase the carbon sequestration capacity.
Subject(s)
Carbon Sequestration , Ecosystem , Urbanization , China , Rural Population , Environmental MonitoringABSTRACT
Long-term, daily, and gap-free Normalized Difference Vegetation Index (NDVI) is of great significance for a better Earth system observation. However, gaps and contamination are quite severe in current daily NDVI datasets. This study developed a daily 0.05° gap-free NDVI dataset from 1981-2023 in China by combining valid data identification and spatiotemporal sequence gap-filling techniques based on the National Oceanic and Atmospheric Administration daily NDVI dataset. The generated NDVI in more than 99.91% of the study area showed an absolute percent bias (|PB|) smaller than 1% compared with the original valid data, with an overall R2 and root mean square error (RMSE) of 0.79 and 0.05, respectively. PB and RMSE between our dataset and the MODIS daily gap-filled NDVI dataset (MCD19A3CMG) during 2000 to 2023 are 7.54% and 0.1, respectively. PB between our dataset and three monthly NDVI datasets (i.e., GIMMS3g, MODIS MOD13C2, and SPOT/PROBA) are only -5.79%, 4.82%, and 2.66%, respectively. To the best of our knowledge, this is the first long-term daily gap-free NDVI in China by far.
ABSTRACT
There is increasing concern regarding the substantial enrichment of Cd during the weathering of carbonate rocks and subsequent risks posed to the ecological environment and food security in karst areas. However, the incomplete understanding of Cd migration mechanisms and material sources restricts soil pollution control and land management. This study investigated the migration regulation of Cd during soil formation and erosion in karst areas. The results demonstrate that soil Cd concentration and bioavailability are both significantly higher in alluvium compared with those in eluvium. This increase is primarily attributed to the chemical migration of active Cd, rather than the mechanical migration of inactive Cd. Additionally, we analyzed the Cd isotopic characteristics of rock and soil samples. The isotopic composition of the alluvial soil was -0.18 ± 0.01 , which is obviously heavier than the δ114/110Cd value of the eluvium (-0.78 ± 0.06 ). The Cd isotopic fingerprint revealed that the active Cd in the alluvium of the study profile was probably derived from the corrosion of carbonate rocks rather than by eluviation of the eluvium. Moreover, Cd tends to occur in soluble mineral components of carbonate rocks rather than in residues, which suggests that carbonate weathering has a great potential to release active Cd into the environment. It is estimated that the Cd release flux caused by carbonate weathering is 5.28 g Cd km-2 yr-1, accounting for 9.30 % of the anthropogenic Cd flux. Therefore, the corrosion of carbonate rocks is a substantial natural Cd source and poses significant potential risks to the ecological environment. It is suggested that the contribution of Cd from natural sources should be considered during ecological risk assessments and studies of the global Cd geochemical cycle.
ABSTRACT
Karst ecosystems are important to several billion people, so it is necessary to accurately diagnose and evaluate the health of these ecosystems for socioeconomic development; however, the existing evaluation methods have many limitations, so they cannot accurately evaluate the ecosystem health in karst areas. In particular, they ignore the influence and restriction of the soil formation rate on the ecosystem health. To this end, we established a new index to represent the actual health status of karst ecosystems. The soil formation rate was found to pose a threat to the health of 28 % of the world's karst ecosystems, covering an area of 594 km2. In addition, a dataset of global karst ecosystem health index values with a spatial resolution of about 8 km × 8 km from 2000 to 2014 was created, and the proportion of unhealthy areas was found to be as high as 75.91 %. This study highlights the contribution of the soil formation rate to karst ecosystem health and provides a new method and deeper scientific understanding for further accurate evaluation of karst ecosystem health, which can improve future ecosystem health research and social management.
Subject(s)
Ecosystem , Soil , Humans , Soil Microbiology , ChinaABSTRACT
The accurate determination of the carbon-neutrality capacity (CNC) of a region is crucial for developing policies related to emissions and climate change. However, a systematic diagnostic method for determining the CNC that considers the rock chemical weathering carbon sink (RCS) is lacking. Moreover, it is challenging but indispensable to establish a fast and practical index model to determine the CNC. Here, we selected Guizhou as the study area, used the methods for different types of carbon sinks, and constructed a CNC index (CNCI) model. We found that: (1) the carbonate rock chemical weathering carbon sink flux was 30.3 t CO2 km-2 yr-1. Guizhou accounted for 1.8% of the land area and contributed 5.4% of the carbonate chemical weathering carbon sink; (2) the silicate rock chemical weathering carbon sink and its flux were 1.44 × 103 t CO2 and 2.43 t CO2 km-2 yr-1, respectively; (3) the vegetation-soil ecosystem carbon sink and its flux were 1.37 × 108 t CO2 and 831.70 t CO2 km-2 yr-1, respectively; (4) the carbon emissions (CEs) were 280 Tg CO2, about 2.8% of the total for China; and (5) the total carbon sinks in Guizhou were 160 Tg CO2, with a CNCI of 57%, which is 4.8 times of China and 2.1 times of the world. In summary, we conducted a systematic diagnosis of the CNC considering the RCS and established a CNCI model. The results of this study have a strong implication and significance for national and global CNC determination and gap analysis.
ABSTRACT
Human well-being in many countries lags behind the gross domestic product (GDP) due to the rapid changes in the socio-economic environment that have occurred for decades. However, the mechanisms behind this complex phenomenon are still unclear. This study revealed the changes in human well-being in China from 1995 to 2017 by revising the genuine progress indicator (GPI) at the national level and further quantified the contribution of interfering factors that have driven the increase in the GPI. The results indicated that: (1) The per capita GPI of China showed an increasing trend with an annual growth rate of 12.43%. The changes in the GPI followed the same pattern as economic development, rather than presenting the phenomenon of economic growth combined with a decline in welfare that has been recorded in some countries and regions. (2) The increase in human well-being was mainly driven by economic growth, but it was most sensitive to social factors. (3) Increasing income inequality and the cost of lost leisure time contributed obvious negative impacts (24.69% and 23.35%, respectively) to the per capita GPI. However, the increase in personal consumption expenditures, the value of domestic labor, ecosystem service value, and net capital growth accelerated the rise in the GPI, with positive contribution rates of 30.69%, 23%, 20.54%, and 20.02%, respectively. (4) The continuous increase in economic investment and the strengthening of social management due to policy adjustments completely counteracted the negative impacts on human well-being, thus leading to a great increase in the per capita GPI. Such insights could provide theoretical support for decision making and policy implementation to improve global human well-being.
Subject(s)
Economic Development , Ecosystem , China , Gross Domestic Product , Humans , PolicyABSTRACT
Stem cell therapy is a thriving topic of interest among researchers and clinicians due to evidence of its effectiveness and promising therapeutic advantage in numerous disease conditions as presented by novel biomedical research. However, extensive clinical application of stem cells is limited by its storage and transportation. The emergence of cryopreservation technology has made it possible for living organs, tissues, cells and even living organisms to survive for a long time at deep low temperatures. During the cryopreservation process, stem cell preparations are subject to three major damages: osmotic damage, mechanical damage, and peroxidative damage. Therefore, Assessing the effectiveness and safety of stem cells following cryopreservation is fundamental to the quality control of stem cell preparations. This article presents the important biosafety and quality control parameters to be assessed during the manufacturing of clinical grade stem cell products, highlights the significance of preventing cryodamage. and provides a reference for protocols in the quality control of stem cell preparations.
ABSTRACT
Climatic and non-climatic factors affect the chemical weathering of silicate rocks, which in turn affects the CO2 concentration in the atmosphere on a long-term scale. However, the coupling effects of these factors prevent us from clearly understanding of the global weathering carbon sink of silicate rocks. Here, using the improved first-order model with correlated factors and non-parametric methods, we produced spatiotemporal data sets (0.25° × 0.25°) of the global silicate weathering carbon-sink flux (SCSFα ) under different scenarios (SSPs) in present (1950-2014) and future (2015-2100) periods based on the Global River Chemistry Database and CMIP6 data sets. Then, we analyzed and identified the key regions in space where climatic and non-climatic factors affect the SCSFα . We found that the total SCSFα was 155.80 ± 90 Tg C yr-1 in present period, which was expected to increase by 18.90 ± 11 Tg C yr-1 (12.13%) by the end of this century. Although the SCSFα in more than half of the world was showing an upward trend, about 43% of the regions were still showing a clear downward trend, especially under the SSP2-4.5 scenario. Among the main factors related to this, the relative contribution rate of runoff to the global SCSFα was close to 1/3 (32.11%), and the main control regions of runoff and precipitation factors in space accounted for about 49% of the area. There was a significant negative partial correlation between leaf area index and silicate weathering carbon sink flux due to the difference between the vegetation types. We have emphasized quantitative analysis the sensitivity of SCSFα to critical factors on a spatial grid scale, which is valuable for understanding the role of silicate chemical weathering in the global carbon cycle.
Subject(s)
Carbon Dioxide , Carbon Sequestration , Carbon Dioxide/analysis , Rivers , Silicates/analysis , WeatherABSTRACT
Vegetation changes in karst areas are controlled by the soil formation rate (SFR) and soil moisture (SM). However, little is known about their thresholds and global control patterns. To this end, based on high-precision climate and vegetation data for 2000-2014, using Pearson correlation analysis, the Hurst index, and change-point analysis, the thresholds of the SFR and SM in vegetation growth in karst areas were identified. Furthermore, a spatial map (0.125° × 0.125°) of the global karst ecosystem with a static/dynamic limitation zone was established. We found that the net primary productivity (NPP) in 70% of the global climate zones exhibited a dual restriction relationship with the SM and SFR. The limitations of the SFR and SM in vegetation growth were most obvious in subpolar and semi-arid climates. In addition, their ecological thresholds were 25.2 t km-2 yr-1 and 0.28 m3 m-3, respectively. The static limitation of the SFR on the NPP in karst areas accounted for 28.37%, and the influence of the SM enhanced this limit (21.79%). The limitation of the SFR on vegetation was mainly concentrated in Boreal forests (17%), and the limitation of the SM was mainly concentrated in tropical savannas (12%). The NPP and the Normalized Difference Vegetation Index (NDVI) were the most sensitive to changes in the SM and SFR. Moreover, the analysis based on 14 ecologically limitation karst areas further revealed that the reduction in these factors may cause the tropical rain forest to experience degradation. It can be seen that the SM enhanced the limiting effect of the SFR on vegetation in karst areas. In short, this interpretation of karst vegetation limitations provides a deeper understanding of and approach to ecosystem evolution and vegetation restoration in these regions.
Subject(s)
Ecosystem , Soil , China , Desert ClimateABSTRACT
Eco-hydrological processes affect the chemical weathering carbon sink (CS) of rocks. However, due to data quality limitations, the magnitude of the CS of rocks and their responses to eco-hydrological processes are not accurately understood. Therefore, based on Global Erosion Model for CO2 fluxes (GEM-CO2 model), hydrological site data, and multi-source remote sensing data, we produced a 0.05° × 0.05° resolution dataset of CS for 11 types of rocks from 2001 to 2018. The results show that the total amount of CS of global rocks is 0.32 ± 0.02 Pg C, with an average flux of 2.7 t C km-2 yr-1, accounting for 53% and 3% of the "missing" carbon sink and fossil fuel emissions, respectively. This is 23% higher than previous research results, which may be due to the increased resolution. Although about 60% of the CS of global rocks are in a stable state, there are obvious differences among rocks. For example, the CS of carbonate rocks exhibited a significant increase (0.30 Tg C/yr), while the CS of siliceous clastic sedimentary rocks exhibited a significant decrease (-0.06 Tg C/yr). Although temperature is an important factor affecting the CS, the proportion of soil moisture in arid and temperate climate zones is higher (accounting for 24%), which is 3.6 times that of temperature. Simulations based on representative concentration pathways scenarios indicate that the global CS of rocks may increase by about 28% from 2050 to 2100. In short, we produced a set of high-resolution datasets for the CS of global rocks, which makes up for the lack of datasets in previous studies and improves our understanding of the magnitude and spatial pattern of the CS and its responses to eco-hydrological processes.
ABSTRACT
The aim of this work was to evaluate the quality of the five mono-cultivar (Frantoio, Leccino, Picholine, Coratina and Ezhi-8) virgin olive oils (Mc-VOOs) produced in Longnan (China) from 2013 to 2017 through analysing the organoleptic quality, physicochemical properties, phenolic contents, antioxidant activity and fatty acid composition. The leading principal components for assessing the quality of Mc-VOOs were extracted by principal component analysis (PCA). The results indicated that the five Mc-VOOs showed obvious differences (p < 0.05) in flavour and substance composition with the variation of cultivar and production year; however, the same cultivar of VOO displayed certain homogeneity in five consecutive years of assessment. The five Mc-VOOs were rich in phenolic compounds and unsaturated fatty acids such as oleic acid. The quality of VOO was mainly determined by the genetic characteristics of olive cultivar, meanwhile, fruit maturity, soil and climate factors also affected its quality. The content of phenolic compound, DPPH· scavenging rate, proportion of unsaturated fatty acids and iodine value of Coratina were the highest, on the contrary, Ezhi-8 was the lowest in general. The results of PCA showed that the five leading principal components to evaluate the quality of Mc-VOOs were oleic acid, linoleic acid, acid value, total phenol and trace components (such as C20:1 and squalene) successively. In conclusion, the five Mc-VOOs from Longnan show excellent quality and have certain uniformity in different production years.
Subject(s)
Antioxidants/analysis , Fatty Acids, Unsaturated/analysis , Food Analysis/methods , Food Quality , Olive Oil/chemistry , Phenols/analysis , Chemical Phenomena , China , Time FactorsABSTRACT
Carbon emissions from land use (E LUC) are an important part of anthropogenic CO2 emissions, but its size and location remain uncertain, and our knowledge of the relationship between E LUC and GDP remains partial. We showed that the carbon emissions directly caused by land use change (direct E LUC) during 1992-2015 was 26.54 Pg C (1.15 Pg C yr-1), with a decreased trend and a net reduction rate of -0.15 Pg C yr-1. The areas that exhibited reductions were concentrated in South America, Central Africa, and Southeast Asia, and those with increments were scattered in Northwestern North America, Eastern South America, Central Africa, East Asia, and parts of Southeast Asia. For the indirect carbon emissions from the utilization of built-up land (indirect E LUC), it manifested an upward trend with a total emission of 27.51 Pg C (1.2 Pg C yr-1). The total value resulted by global E LUC was $136.3 × 109 US, and the value of annual was equivalent to 3.7 times the GDP of the Central African Republic in 2015 ($5.93 × 109 US yr-1). Among the 79 countries and regions considered in this study, 54 represented the upward GDP with increased emissions, and only 25 experienced GDP growth with emission reductions. These findings highlight the pivotal role of land use change in the carbon cycle and the significance of coordinated development between GDP and carbon emissions.
ABSTRACT
The weathering carbon sink (CS) of rocks has a sensitive response to different influencing factors, and it is important to accurately distinguish this response in the global carbon cycle. However, no quantitative analysis of the response mechanism has been performed. In this study, the CS of the 12 types of terrestrial rocks in China from 2000 to 2014 is estimated using the GEM-CO2 model. The relative contribution rates of climate change and ecological restoration to the CS are quantitatively evaluated using the Lindeman-Merenda-Gold model. Results showed that: (1) The CS of terrestrial rocks in China was 17.69 Tg C yr-1, and the CS flux (CSF) was 2.53 t C km-2 yr-1; mixed sedimentary rocks had the highest CS (6.89 Tg C yr-1), and carbonate rocks had the highest CSF (5.8 t C km-2 yr-1). (2) The average annual CSF slightly decreased at a rate of 5.4 kg C km-2 yr-1; the areas of the CSF that decreased in the south were the areas where water budget decreased significantly, and it was the areas with a reduced water budget and ecological deterioration in the north. (3) The relative contribution rates of water budget and precipitation reached 57% and 35%, respectively; the response of the CSF to temperature was evident in areas with low or decreasing temperatures, and the influence of fractional vegetation cover (FVC) on the CSF in low value area was evident. (4) Mixed sedimentary rocks and carbonate rocks displayed a more evident reduction trend in the CSF than other rocks. This research verified the applicability of the GEM-CO2 model in China and presented a scientific basis for quantitative assessment of the impact of climate change and ecological restoration on the CSF.
ABSTRACT
Land use affects the accumulation of heavy metals in soil, which will endanger ecological safety and human health. Taking the village as an administrative unit, the ecological safety and health risks of heavy metals, namely, Cr, Cu, Zn, and Pb in soils in the Houzhai River Watershed of Guizhou Province, China, were evaluated based on land use types by the Hakanson potential ecological risk methods and human health risk model. Results showed that the spatial heterogeneity of Cu and Zn was greatly affected by primary structural factors, and Cr and Pb were interfered by both structural factors and human activities. The geo-accumulation index of the heavy metals showed a light pollution in the study area. The comprehensive potential ecological risk of heavy metal in the area was divided into three levels: slight, moderate, and intense, and it is spatially high in the northwest and low in the southeast. Both non-carcinogenic risk and carcinogenic risk of the heavy metals to the human body are not significant and are acceptable. The risks of children are higher than adults, and direct intake is the primary route of exposure in the area. The potential ecological risk and human health risk of soil heavy metals are relatively obviously affected by digital elevation data and normalized vegetation index. The study has certain reference value for the prevention and control of regional soil heavy metal risk.
Subject(s)
Environmental Monitoring , Metals, Heavy/analysis , Soil Pollutants/analysis , Soil/chemistry , China , Humans , Risk AssessmentABSTRACT
A refined yet compact analytical formulation is presented for the time-domain elastodynamic response of a three-dimensional half-space subject to an arbitrary internal or surface force distribution. By integrating Laplace and Hankel transforms into a method of displacement potentials and Cagniard's inversion concept, it is shown that the solution can be derived in a straightforward manner for the generalized classical wave propagation problem. For the canonical case of a buried point load with a step time function, the response is proved to be naturally reducible with the aid of a parametrized Bessel function integral representation to six wave-group integrals on finite contours in the complex plane that stay away from all branch points and the Rayleigh pole except possibly at the starting point of the contours. On the latter occasions, the possible singularities of the integrals can be rigorously extracted by an extended method of asymptotic decomposition, rendering the residual numerical computation a simple exercise. With the new solution format, the arrival time of each wave group is derivable by simple criteria on the contour. Typical results for the time-domain response for an internal point force as well as the degenerate case of a surface point source are included for comparison and illustrations.
ABSTRACT
An understanding of the enrichment mechanisms of cadmium (Cd) and arsenic (As) in the process of rock weathering and soil formation is essential to develop agriculture according to local conditions. However, the enrichments of soil Cd and As under natural background conditions in karst areas are still uncertain. The enrichment factor, geo-accumulation index, redundancy analysis, and other methods were used to analyze the enrichment degree and the influencing factors of Cd and As on 5 rock-soil profiles and 15 topsoil samples, which were collected from a karst forest area in Libo County, Guizhou Province. The results showed that the enrichment process was divided into three stages. In the first stage, Cd and As were enriched in carbonate rocks, and their mean concentrations were 1.65 and 3.9 times those of the corresponding abundance of the crust. In the second stage, the enrichment of the parent rock into the soil, the enrichment factors of Cd and As in the parent material horizon relative to the bedrock horizon were 9.2 and 2.82, respectively. The third stage refers to the enrichments of Cd and As in the topsoil, where Cd enrichment was more obvious than that of As. Soil organic matter (SOM) and phosphorus (P) are important factors that influenced the enrichments of Cd and As in the topsoil. The functional groups of SOM were complexed with Cd and As; P easily formed precipitates with Cd, and the tree litter was fed back to the topsoil, which may be the reason for the surface enrichment of Cd and As. This study will help the scientific community understand the enrichment mechanisms of soil Cd and As in karst areas.
Subject(s)
Arsenic/chemistry , Cadmium/chemistry , Forests , Soil Pollutants/chemistry , Soil/chemistry , China , Environmental MonitoringABSTRACT
The magnitudes, spatial distributions and contributions to global carbon budget of the global carbonate carbon sink (CCS) still remain uncertain, allowing the problem of national measurement of CCS remain unresolved which will directly influence the fairness of global carbon markets and emission trading. Here, based on high spatiotemporal resolution ecological, meteorological raster data and chemical field monitoring data, combining highly reliable machine learning algorithm with the thermodynamic dissolution equilibrium model, we estimated the new CCS of 0.89⯱â¯0.23â¯petagrams of carbon per year (Pgâ¯Câ¯yr-1), amounting to 74.50% of global net forest sink and accounting for 28.75% of terrestrial sinks or 46.81% of the missing sink. Our measurement for 142 nations of CCS showed that Russia, Canada, China and the USA contribute over half of the global CCS. We also presented the first global fluxes maps of the CCS with spatial resolution of 0.05°, exhibiting two peaks in equatorial regions (10°S to 10°N) and low latitudes (10°N to 35°N) in Northern Hemisphere. By contrast, there are no peaks in Southern Hemisphere. The greatest average carbon sink flux (CCSF), i.e., 2.12â¯tCâ¯ha-1â¯yr-1, for 2000 to 2014 was contributed by tropical rainforest climate near the equator, and the smallest average CCSF was presented in tropical arid zones, showing a magnitude of 0.26â¯tCâ¯ha-1â¯yr-1. This research estimated the magnitudes, spatial distributions, variations and contributions to the global carbon budget of the CCS in a higher spatiotemporal representativeness and expandability way, which, via multiple mechanisms, introduced an important sink in the terrestrial carbon sink system and the global missing sink and that can help us further reveal and support our understanding of global rock weathering carbon sequestration, terrestrial carbon sink system and global carbon cycle dynamics which make our understanding of global change more comprehensive.
ABSTRACT
This study aims to reveal the runoff variation characteristics of long time series in a karst region, analyse comprehensively its different driving factors, and estimate quantitatively the contribution rates of climate change and human activities to net runoff variation. Liudong river basin, a typical karst watershed in southwest China, is the study site. Statistical methods, such as linear fitting, the Morlet wavelet analysis, normalized curve and double mass curve, are applied to analyse the runoff of the watershed. Results show that the runoff in the karst watershed during the research period exhibits a three-stage change and the abrupt change points are the years 1981 and 2007: (1) 1968-1980, the runoff initially exhibited a trend of sustained decreasing and then an abrupt fluctuation. The runoff was obviously destroyed through precipitation-producing processes. Improper land utilisation and serious forest and grass destruction intensified the fluctuation variation amplitude of the runoff. (2) 1981-2006, the changing processes of runoff and precipitation exhibited good synchronism. Precipitation significantly affected runoff variation and human activities had a slight interference degree. (3) 2007-2013, the fluctuation range of runoff was considerably smaller than that of precipitation. The significant growth of forest and grassland areas and the increase in water consumption mitigated runoff fluctuation and greatly diminished runoff variation amplitude. According to calculation, the relative contribution rates of precipitation and human activities to net runoff variation with 1981-2007 as the reference period were -81% and 181% in average, respectively, during 1968-1980, and -117% and 217% in average, respectively, during 2007-2013. In general, the analysis of runoff variation trend and of the contribution rate of its main influencing factors in the typical karst watershed for nearly half a century may be significant to solve the drought problem in the karst region and for the sustainable development of the drainage basin.
Subject(s)
Climate Change , Hydrology , Water Movements , China , Environmental Monitoring , Forests , Human Activities , Humans , Hydrology/methods , Natural Resources , RainABSTRACT
Land surface temperature (LST) can reflect the land surface water-heat exchange process comprehensively, which is considerably significant to the study of environmental change. However, research about LST in karst mountain areas with complex topography is scarce. Therefore, we retrieved the LST in a karst mountain area from Landsat 8 data and explored its relationships with LUCC and NDVI. The results showed that LST of the study area was noticeably affected by altitude and underlying surface type. In summer, abnormal high-temperature zones were observed in the study area, perhaps due to karst rocky desertification. LSTs among different land use types significantly differed with the highest in construction land and the lowest in woodland. The spatial distributions of NDVI and LST exhibited opposite patterns. Under the spatial combination of different land use types, the LST-NDVI feature space showed an obtuse-angled triangle shape and showed a negative linear correlation after removing water body data. In summary, the LST can be retrieved well by the atmospheric correction model from Landsat 8 data. Moreover, the LST of the karst mountain area is controlled by altitude, underlying surface type and aspect. This study provides a reference for land use planning, ecological environment restoration in karst areas.