Changsha City Research Articles

Land cover classification and urbanization monitoring using Landsat data: A case study in Changsha city, Hunan province, China

The United Nations predicts that by 2050, 64.1% of the developing world and 85.9% of the developed world will be urbanized. This has resulted in a rapid change in land use and land cover types in the areas surrounding cities in all countries, particularly in China, which determines the relevance of this article. The aim of the study was to evaluate the dynamics of land cover change in Changsha City, Hunan Province, China, between 2005 and 2020, using Landsat time series satellite images and the Random Forest classification algorithm. The data acquisition, pre-processing, and analysis were conducted on the Google Earth Engine (GEE) publicly available online platform. Land cover thematic continuous raster maps were produced using ESRI ArcGIS 10.5.1 software. The overall classification accuracy was obtained by more than 83% for every produced map and the Kappa coefficient was 0.84 and higher, which approves the reliable classification results that are close to similar recent studies in terms of obtained accuracy. The study shows that from 2005 to 2020, the area of settlement in Changsha City, China, increased significantly, with an exponential increase in urban area from 3.23% to 15.95%. The proportion of forest cover gradually decreased from 2005 to 2015 but increased from 2015 to 2020. Cropland was the second most dominant land cover type, with a peak of almost 50% in 2010. Water bodies remained stable at around 3%. The proportion of open soil and bare land cover fluctuated between 180 and 400 km2 (1.5-3%). The study suggests that the offered monitoring approach provides reliable results, and the research findings can be used for sustainable urban planning and management, as well as conservation and development initiatives. The remote sensing data and advanced GIS technologies can provide decision-makers with the accurate data to ensure sustainable development in this area

Does Regional Urbanization Promote Balanced Land Development? Evidence from Long Time Series Satellite Imagery

The urban megaregion has been promoted as among the major urbanization forms in New-Type Urbanization in China, which aims to promote more balanced development among cities and between the urban and rural areas in a region. While numerous studies have examined developed land expansion in cities worldwide using remotely sensed imagery, fewer have investigated its dynamic process in a rural area and the differences in the growth magnitude and expansion morphology between urban and rural areas. Using Landsat imagery from 1986 to 2020, we examined the spatiotemporal patterns of developed land in both the urban and rural areas in the Changsha–Zhuzhou–Xiangtan urban megaregion, China, using morphological analysis. We found that (1) the differences in the growth magnitude between the urban and rural areas varied between the different-sized cities, with increases in the largest city of Changsha, but decreases in the smaller ones of Zhuzhou and Xiangtan, although there was a slight increase at the megaregional scale. (2) The dynamic process of developed land in rural areas was similar to that in urban areas but showed a clear time-lag effect, where the dominant expansion types in urban areas shifted from edge to infilling expansion and to another edge expansion in 1986–2000, 2000–2010, and 2010–2020, whereas that in rural areas changed from outlying to edge expansion in 1986–2000 and 2000–2020. (3) The positive relationships between the growth speed and outlying and edge expansion suggested that the CZT urban megaregion was in the rapid outward expansion stage. Such a pattern may cause similar ecological effects, such as habitat fragmentation and urban heat archipelagos, to that in the eastern megaregions. Understanding such differences and their changes in the urban and rural areas will help optimize the strategies of urban megaregion sustainability.

Linking urban park cool island effects to the landscape patterns inside and outside the park: A simultaneous equation modeling approach

Urban parks have significant cooling effects that alleviate the urban heat island (UHI). The park cool island intensity (PCII), the temperature difference between outside and inside a park, is a widely used indicator of a park’s cooling ability. Understanding the driving factors of the PCII is crucial for better urban park planning and management. Taking the subtropical city of Changsha, China, as a case study, factors such as the landscape patterns inside and outside a park and the geometric morphology of a park were investigated, based on 153 urban parks. A novel simultaneous equation modeling (SEM) approach was used to account for the mutual interactions between the temperatures of a park and its buffer. The results show that: (1) Park geometric morphology and landscape patterns inside and outside the park all significantly impact the PCII. Specifically, doubling the park size can increase the PCII by 0.8 K. Increasing by ten percent the tree cover and water cover in the park can enhance the PCII by 0.12 K and 0.41 K, respectively. Increasing the mean tree patch size by 1 ha can increase the PCII by 0.43 K. Decreasing by one unit the mean tree patch shape index can increase the PCII by 0.31 K. (2) An elasticity analysis, which measures the PCII percent change resulting from one percent change in a driving factor, indicates the relative importance ranking of these driving factors: percent cover of impervious surface outside the park (0.77), park size (0.72), percent cover of tree within the park (0.51), percent cover of water within the park (0.12), and mean patch size of tree cover within the park (0.086). To enhance the PCII, we recommend building parks in the hot areas of the city, increasing their size, increasing the percentages of tree cover and water cover in the park, and optimizing the spatial configuration of the tree cover in the park (i.e., aggregating trees in a smaller number of large patches and reducing the irregularity of tree patches).

Influence of academic stress and school bullying on self-harm behaviors among Chinese middle school students: The mediation effect of depression and anxiety.

The purpose of this study was to explore the relationship between academic stress, school bullying and self-harm behaviors among Chinese middle school students and to further explore the impact of anxiety and depression on this relationship. The students (aged 12-16 years) in a middle school in Changsha city were invited to respond to a questionnaire through an online platform. The Patient Health Questionnaire-9 (PHQ-9) and Generalized Anxiety Disorder-7 (GAD-7) were used to assess the severity of anxiety and depressive symptoms, respectively. The experience of being bullied, academic stress, and self-harm behaviors were assessed using several questions on the basis of previous studies. A total of 1,313 middle school students completed the study, and 3.40% and 4.10% of them reported suicide attempts (SAs) and non-suicidal self-injury (NSSI), respectively. Univariate logistic regression analysis revealed that anxiety symptoms (OR = 1.23, 95% CI: 1.18-1.28; OR = 1.25, 95% CI: 1.19-1.31), depressive symptoms (OR = 1.20, 95% CI: 1.16-1.25; OR = 1.26, 95% CI: 1.20-1.31), school bullying (OR = 3.8, 95% CI: 2.11-6.89; OR = 2.76, 95% CI: 1.39-5.47), and academic stress (OR = 2.20, 95% CI: 1.27-3.80; OR = 3.80, 95% CI: 1.20-7.25) were common factors of NSSI and SAs. In addition, depressive symptoms showed a mediating effect on the association of school bullying and academic stress with SAs or NSSI, and anxiety symptoms showed a mediating effect on the association of school bullying and academic stress with NSSI only. Appropriate strategies are needed to reduce academic pressure and prevent school bullying. Meanwhile, negative emotions such as depression and anxiety should be evaluated and intervened in to prevent self-harm behaviors among middle school students.

Beyond the Wall: Mapping Christian Fundamentalism in Hunan During the 1920s

The Hunan Bible Institute (HBI) was a prominent missionary organization based out of the city of Changsha, the provincial capital of Hunan province, located far in China’s interior. By the 1920’s the HBI built a large compound located outside the eastern gate of the city, which mainly functioned as a training school for Chinese converts and missionaries. Despite Hunan’s reputation as one of the most radically anti-foreign regions of China, early efforts of evangelistic outreach were mainly achieved through the efforts of small “colporteur teams,” who were sent out on small boats along Hunan’s complex network of rivers and canals. At the same time, archival evidence has shown how the story of how HBI acquired the property to build its spacious campus initially proved controversial and was indicative of how wealthy foreign institutions maintained a complex relationship with local interests during a very turbulent decade in China’s modern history..

Psychosocial characteristics pattern correlated with HIV-related risky sexual behavior among HIV-negative men who have sex with men: a latent profile analysis

Men who have sex with men (MSM) have become a high risk population of HIV infection due to their risky sexual behaviors. The latent pattern of psychosocial characteristics plays an important effect in HIV-related risky behaviors among HIV-negative MSM. Participants were recruited from Wuhan, Nanchang, and Changsha city from September 2017 to January 2018. Social support was assessed by the multidimensional scale of social support, Connor-Davidson Resilience scale-10 items for reliance, the assessment of Stigma towards Homosexuality for sexual minority stigma, the Likert subscale of nondisclosure for identity concealment, the ACE questionnaire-Kaiser-CDC for adverse childhood experience, the Centers for Epidemiological Studies Depression Scale for depression. Latent profile analysis (LPA) and multivariate regression were used to analyze the data. Three psychosocial characteristic patterns were revealed by the LPA. "Social support and resilience group" (SR group), "Identity concealment group" (IC group) and "Adverse childhood experience" (ACE group) were identified, respectively. In comparison with "SR group", "IC group" have a higher likelihood of one-night male partners (AOR = 2.74, 95%CI = [1.54, 4.90]), both fixed and one-night male partners (AOR = 2.01, 95%CI = [1.34, 3.01]) and HIV-unsure male partner (AOR = 2.12, 95%CI = [1.44, 3.13]). Similarly, "ACE group" were more likely having inconsistent condom use (AOR = 2.58, 95%CI = [1.41, 4.73]), and having sex with HIV-positive male partner (AOR = 4.90, 95%CI = [1.95, 12.30]) with comparison of "SR group". In addition, we further revealed that "ACE group" had a higher ratio (90.0%) of inconsistent condom use among MSM whose male partners were HIV-positive. Six important psychosocial factors were divided into three latent pattern classes. Compared with "SR group", "IC group" and "ACE group" were more likely to engage in HIV-related risky sexual behaviors. Further research may pay more attention to "IC group" and "ACE group" for targeted intervention.

Cycle-Based Estimation on Lane-Level Queue Length at Isolated Signalized Intersection Using License Plate Recognition Data

Queue length is an important parameter to evaluate the congestion level of urban intersections. Abundant methods based on different data sources, such as loop detector data and mobile sensor data, for estimating queue length have received wide attention. A license plate recognition (LPR) system recording vehicle information can be used as a data source to estimate lane-level queue length. In this study, an improved method is proposed for cycle-based queue length estimation at an isolated signalized intersection using LPR data, considering the residual queued vehicles under oversaturated conditions. First, a modified interpolation method is developed to infer the travel time of unmatched vehicles. Then, the complete arrival and departure information are processed as three characteristic parameters of vehicles, which are the input to the maximum probability function for queue length estimation at each lane. Finally, the proposed model is validated using actual cycle maximum queue length collected from a video camera and LPR data in Changsha city, China. The numerical results showed that the proposed model can achieve accurate estimation for lane-level queue length.

Spatiotemporal variation of housing price in megacities based on household registration: Taking Changsha City as an example

Spatiotemporal variation of housing price in megacities based on household registration: Taking Changsha City as an example

Effects of heavy rainfall and outer river level on urban waterlogging in hilly areas of South China: a case study of Nanhu Port, Changsha City

Effects of heavy rainfall and outer river level on urban waterlogging in hilly areas of South China: a case study of Nanhu Port, Changsha City

“双碳”目标下碳排放量变化趋势及影响因素分析——以长沙市碳排放为例

“双碳”目标下碳排放量变化趋势及影响因素分析——以长沙市碳排放为例

Retracted: Analysis of Prevalence, Influencing Factors, and Countermeasures of Short Stature in Children and Adolescents Aged 6∼14 in Furong District, Changsha City, in 2020.

[This retracts the article DOI: 10.1155/2021/3933854.].

A Subpixel Mapping Method for Urban Land Use by Reducing Shadow Effects

Urban land use classification is significant for urban development planning. Considering complex environments of urban surface features, traditional semantic segmentation methods are difficult to solve the problems of mixed pixels and limited spatial resolution of images. The subpixel mapping technology is an effective method to solve the above problems in urban land use classification. However, traditional subpixel mapping methods are sensitive to mountain shadow, high-rise building shadow and impermeable surface heterogeneity, resulting in false classification. Therefore, we propose a subpixel mapping method that can reduce the shadow effect. This method uses a multi-index feature fusion strategy to optimize the abundance of the shadow errors in the abundance image, and uses a super-resolution reconstruction neural network model to reconstruct the optimized abundance image for the subpixel mapping of urban land use. Experiments were conducted on sentinel-2 images obtained over Yuelu District of Changsha City, Hunan Province, China. The experimental results show that the method proposed in this article can effectively overcome the influence of building shadows and mountain shadows in urban land cover classification and is superior to traditional subpixel/pixel spatial attraction model, radial basis function, super-resolution subpixel mapping, and other methods in the effect and accuracy of urban land use subpixel mapping.

A Brief Report on the Collapse of Self-Built Houses on 29 April 2022, in Changsha, China.

A self-built house collapsed in Changsha City, Hunan Province, on 29 April 2022, causing 53 people to be trapped and 39 people to go missing. The tragedy caused a huge loss of life, so the stability of self-built houses has a non-negligible impaction on public safety. This report presents causes of the incident, rescue operations, cause analysis, and the analytic hierarchy process (AHP). The main conclusions about the reasons for the collapse include: (a) reckless heightening, (b) unreasonable structure, (c) adverse geological conditions, (d) architectural vulnerabilities, (e) negligence of competent authorities, and (f) lack of security awareness. This paper provides a reference for avoiding similar security incidents in the future.

The relationship between HIV-related stigma and HIV self-management among men who have sex with men: The chain mediating role of social support and self-efficacy.

HIV infection becomes a manageable disease, and self-management is one of the key indicators of achieving optimal health outcomes. Men who have sex with men (MSM) living with HIV face many psychosocial challenges when managing HIV infection, such as sexual minority pressure and HIV-related stigma. Higher perceived HIV-related stigma had been related to low self-management. However, the mechanisms underlying the association between HIV-related stigma and HIV self-management are unclear. Two possible mediators include social support and self-efficacy. This study aimed to examine the relationship between HIV-related stigma and HIV self-management among MSM living with HIV and to explore the single mediating effect of social support and self-efficacy and the chain mediating effect of these two variables on this relationship in China. Convenience sampling was used to recruit participants from the Center for Disease Control (CDC) in Changsha City, Hunan province, China. A total of 459 MSM living with HIV completed questionnaires regarding sociodemographic and disease-related information, HIV-related stigma, social support, self-efficacy, and HIV self-management. Descriptive statistics analysis, one-way ANOVA, independent t-tests, Pearson's bivariate correlation, and multiple regression were conducted using the SPSS v24.0. Process macro in SPSS was used to analyze the single and chain mediating effect among variables. Our findings showed that the indirect and total effect of HIV-related stigma on HIV self-management was significant, while the direct effect was not statistically significant. Social support and self-efficacy mediated the relationship between HIV-related stigma and HIV self-management, respectively. Moreover, the chain mediating model confirmed that the association between HIV-related stigma and HIV self-management was mediated by social support and self-efficacy sequentially. Future interventions focusing on improving HIV self-management among MSM living with HIV should consider a multi-faced approach.

The Prediction Model of Air Quality in Changsha City Based on Artificial Neural Network

The air quality is a hot topic noticed by all the present society. Although modern technology has helped to collect data of the air position, the huge amount of irregular data also makes it hard to detect the pattern of air pollution. Therefore, this research is to apply data mining to the analysis of the air quality. Data mining is a comprehensive mining of information including trends, features and correlations hidden in data. Data mining can extract the value of data which was not known from numerous random data. This research is based on the daily average values of six major pollutants in Changsha from January 1, 2015, to December 31, 2017, and analyzes the relationship between the air quality and socioeconomic factors of Changsha to establish a prediction model using B-P back propagation neural network. The final model of the research fits the actual data well and predicts the future value of API precisely. However, considering the slow convergence rate and the addition of new samples which may affect the previously learnt samples, further exploration on the B-P neural network model can be launched with other mathematical theories.

Effects of physical activity on regulatory emotional self-efficacy, resilience, and emotional intelligence of nurses during the COVID-19 pandemic.

The normalization of epidemic prevention and control has exacerbated nurses' physical and mental stresses. The important role of physical activity in relieving nurses' physical and mental stresses has received extensive attention from researchers in recent years. The purpose of this study was to investigate the influence of physical activity on the regulatory emotional self-efficacy, resilience, and emotional intelligence of nurses and explain their interactions. The present study adopted the cluster sampling method. From April to May 2022, a total of 500 nurses in six municipal hospitals in Changsha City were selected. Finally, 402 valid data samples were obtained. Afterward, AMOS 23.0 (by maximum likelihood estimation) was used to process the collected data and analyze the proposed hypotheses by using 5,000 bootstrap samples to test the mediating effects of the structural equation model. The results demonstrated that there are positive correlations between physical activity and resilience (standardized coefficients = 0.232, p < 0.001), resilience and regulatory emotional self-efficacy (standardized coefficients = 0.449, p < 0.001), and emotional intelligence and regulatory emotional self-efficacy (standardized coefficients = 0.330, p < 0.001). The positive influence of physical activity on emotional regulation self-efficacy is completely mediated by emotional intelligence and resilience (standardized indirect effect = 0.237, p < 0.01), and this explanatory power is far higher than any previous study (R 2 = 0.49). The positive emotions generated by an individual's physical activity have an important explanatory role for individuals who want to establish more emotional regulation self-efficacy, emotional intelligence, and psychological resilience.

Research on Green View Index of Urban Roads Based on Street View Image Recognition: A Case Study of Changsha Downtown Areas

In this paper, we took the urban roads in the Changsha downtown areas as an example to identify the green view index (GVI) of urban roads based on street view images (SVIs). First, the road network information was obtained through OpenStreetMap, and the coordinate information of sampling points was processed using ArcGIS. Secondly, the SVIs were downloaded from Baidu Map according to the latitude and longitude coordinates of the sampling points. Moreover, semantic segmentation neural network software was used to semantically segment the SVIs for recognizing the objects in each part of the images. Finally, the objects related to green vegetation were statistically analyzed to obtain the GVI of the sampling points. The GVI was mapped to the map in ArcGIS software for data visualization and analysis. The results showed the average GVI of the study area was 12.56%. An amount of 27% have very poor green perception, 40% have poor green perception, 19% have general green perception, 10% have strong green perception, and 4% have very strong green perception. In the administrative districts, the highest GVI is Yuhua District with 14.15%, while the lowest is Kaifu District with 8.75%. The average GVI of the new urban area is higher than that of the old urban area, as the old urban area has higher building density and a lower greenery level. This paper systematically evaluated the levels of GVI and greening status of urban streets within the Changsha downtown areas through SVIs data analysis, and provided guidance and suggestions for the greening development of Changsha City.

Association between Depression, Anxiety Symptoms and Gut Microbiota in Chinese Elderly with Functional Constipation.

in this cross-sectional study, a total of 198 elderly participants (85 male and 113 female) aged over 60 years were recruited. The study was conducted in Changsha city, China. The participants completed an online questionnaire, including The Patient Health Questionnaire-9 (PHQ-9), Generalized Anxiety Disorder-7 (GAD-7), The Patient Assessment of Symptoms (PAC-SYM), and The Patient Assessment of Quality of Life (PAC-QoL). We selected the 16S rDNA V3 + V4 region as the amplification region and sequenced the gut microbiota using the Illumina Novaseq PE250 high-throughput sequencing platform. in total, 30.3% of patients with constipation had depression, while 21.3% had anxiety. The relative abundance of intestinal microbiota in the normal group was higher than that in the anxiety and depression group. According to LEfSe analysis, the relative abundance of g_Peptoniphilus and g_Geobacter in the people without depression and anxiety was higher. The relative abundance of g_Pseudoramibacter-Eubacterium and g_Candidatus-Solibacter in the depression group was lower, and the relative abundance of g_Bacteroides and g_Paraprevotella, g_Cc_115 in the anxiety group was higher. In addition, according to the correlation analysis, g_Aquicella and g_Limnohabitans were negatively correlated with constipation symptoms, anxiety, and depression. this study found that gut microbiota composition may be associated with a higher incidence of anxiety and depression in patients with FC, thus providing insight into the mechanisms that ameliorate mood disorders in patients with FC.

Evaluation of Ecological Service Function of Liquidambar formosana Plantations.

A Liquidambar formosana plantation is a kind of fast-grown forest in the subtropical region, providing a variety of ecosystem services such as superior wood, carbon fixation and oxygen release, and biodiversity maintenance. However, the ecological service function value of Liquidambar formosana plantations is not clear. To gain insights into the characteristics and importance of its ecological and economic benefits, the Liquidambar formosana plantation in the Tianjiling Forest Farm of Changsha City was taken as the specific research object in this paper. The ecological service function evaluation index system for Liquidambar formosana plantations was established based on the relevant research worldwide and the actual situation. The market value method, shadow engineering method, carbon tax method, and other environmental economics methods were used to estimate the value of seven ecological service functions (including organic matter production, carbon fixation and oxygen release, water conservation, soil conservation, soil improvement, air purification, and biodiversity maintenance) of the forest of Liquidambar formosana. The results indicated that the total economic value of ecological service function provided by the Liquidambar formosana plantation of Changsha was 103,277.82 RMB/(hm2·a), and the indirect economic value was 8.47 times that of the direct economic value. Among the seven ecological service functions, the value of carbon fixation and oxygen release was the highest (36,703.33 RMB·hm-2·a-1), thus suggesting that the Liquidambar formosana plantation had strong photosynthesis and significant carbon fixation. This study directly reflects the value of forest ecological service function in the form of currency, which is beneficial to provide more insights into forest ecological service function so as to provide basic data and a scientific basis for the protection, construction, and promotion of the sustainable utilization and development of urban forest resources.

Asynchrony between urban expansion and water environmental protection reshapes the spatial patterns of nitrogen and phosphorus concentrations and N:P stoichiometry in inland small water bodies in Changsha, China

The asynchrony of urban expansion and urban water environmental protection is a common problem in the process of urbanization. Although urban expansion results in population agglomeration and dramatic changes of land use, it also brings municipal water infrastructures to enhance the water quality of urban water bodies. In order to understand the relationship between water quality and urban expansion and water environmental management, total nitrogen (TN) and total phosphorus (TP) concentrations were measured, which were taken from 68 small urban water bodies in three distance bands (&amp;lt;5 km, 5–10 km and &amp;gt;10 km away from the city center of Changsha City, China) and four main water management types of protection, recovery, degradation and fisheries. The results showed that: 1) with increase in distance away from the city center, TN and TP concentrations in small water bodies and the percentage of polluted samples (IV ∼ inferior V) showed an increasing trend. 2) The degree of protection of small urban water bodies in the study area has not been synchronistic with urban expansion. The protected water bodies (long-term protected and recovering) are mainly distributed in the &amp;lt;5 km distance band, and anthropogenic disturbances (degraded water bodies and small water bodies used for fish farming) were mainly distributed in the 5–10 km and &amp;gt;10 km distance bands. Also, degraded and fish-managed water bodies had higher TN and TP contents than protected and recovering water bodies, but their TN:TP ratios were significantly lower. 3) Overall, urban expansion and water body management contributed 55.8% of the variance of TN and TP concentrations and TN:TP ratios in the study area. Water body management alone contributed 22.2%, which was higher than the contribution of urban expansion (7.6%). This shows that the insufficient application of water environmental protection measures has significantly changed the spatial distribution patterns of N and P concentrations and TN:TP ratios in urban small water bodies as the Changsha urban area has expanded. In the process of urban expansion, the simultaneous development of urban water ecological management is essential to ensure the health protection of the urban water environment.