Yunyang County Research Articles

A sauropod tibia with initial fracture from the Middle Jurassic in Yunyang, Chongqing, southwest China

ABSTRACT Among the available palaeopathological results on non-avian dinosaurs, the fracture is the most documented category. Therein, only two sauropod fractured cases have been reported, and no sauropod tibial fracture has been mentioned. In this study, we report a special sauropod tibial fracture from the Middle Jurassic of Yunyang County, Chongqing, southwest China. The morphological observation shows a planar-shaped sauropod tibial fracture, with a rough surface without fracture callus, and does not exhibit other healing manifestations such as swelling. The CT images and energy spectrum data clearly demonstrate the injured cortical bone invaginated into the medullary cavity. Moreover, these data indicate that the tibia fracture is initial, the first valid record of initial fracture in non-avian dinosaurs. This study enhances our knowledge of sauropod limb bone fractures and enriches the pathological information about dinosaur fractures.

Hydrological influences on landslide dynamics in the three gorges reservoir area: an SBAS-InSAR study in Yunyang county, Chongqing

Hydrological influences on landslide dynamics in the three gorges reservoir area: an SBAS-InSAR study in Yunyang county, Chongqing

Isolated freshwater pliosaurid teeth from the Middle Jurassic Xintiangou Formation of Chongqing, China

ABSTRACT Abundant vertebrate remains have been reported from the Middle Jurassic Xintiangou Formation in Yunyang County, Chongqing, China. In this study, we report newly discovered isolated plesiosaurian teeth of various sizes excavated from Yunyang County. The specimens are classified into two types of pliosauroid: one type, has a tooth crown with a circular cross-section and apicobasal ridges that fully cover the enamel surface, extending to the apex. This conical-toothed morphology is typical of plesiosauroids in the Middle Jurassic. The other type exhibits much closer-spaced apicobasal ridges and carinae on the enamel surface. This may represent a transitional taxon between the Middle Jurassic and Late Jurassic pliosaurids. However, due to their fragmentary nature, it is not possible to determine whether the Yunyang specimens belong to a known taxon or represent a new species of Plesiosauria. These specimens suggest a multispecies plesiosaurian assemblage in Yunyang County and further demonstrate that the freshwater plesiosaurians are common in the Jurassic deposits of the Sichuan Basin.

Comparison and quantitative assessment of two regional soil erosion survey approaches

Regional soil erosion surveys are the first step of soil conservation planning. Grid and sampling approaches are commonly used for soil erosion surveys at the regional scale. With the grid approach, the region is divided into grids (e.g., 1 km × 1 km), and the soil erosion rate of each grid was calculated. With the sampling approach, a small portion of the area (typically 4% or less) was taken and then the soil erosion rate was calculated. Based on the above calculation, both approaches evaluated the soil erosion area (which is the area where the soil erosion rate is greater than the soil loss tolerance (t)) and its distribution in the whole region. The purpose of this paper is to compare the assessment results of the two approaches and analyse their practicality using Yunyang County, Chongqing, China (area is 3636 km2). The soil erosion rate, percentage of soil erosion area (PSEA, which is the ratio of the area where the soil erosion rate is greater than the soil loss tolerance (t) to the area of the total study region) and its spatial distribution were compared between the two approaches. The results showed that the grid approach overestimated the average soil erosion rate and PSEA overall for all 33 sample units and the whole region in comparison to the sampling approach. The sampling approach can yield a reasonable spatial distribution of the soil erosion rate in the whole region. In addition, the soil erosion regions were more clustered than those using the grid approach, which can be more suitable for soil conservation planning. Therefore, the sampling approach is an efficient and practical approach in regional soil erosion surveys. The results can provide insights into regional soil erosion surveys.

Study of the impact of reservoir water level decline on the stability treated landslide on reservoir bank

Affected by the reservoir water and rainfall and other factors, the stability of the landslide changes with the different reservoir water level decline rate. Using the Baota landslide in Yunyang County in Three Gorges Reservoir region as an example, and applying the saturated-unsaturated numerical simulation method, the groundwater seepage field is calculated when the reservoir water level rises and declines. The calculated pore water pressure is used for the ultimate equilibrium analysis of landslide, and the effect of reservoir water level drop on landslide stability was discussed. The calculation results show that with the water level falling from 159 m to 145 m, and the increase of the rate of decline in the reservoir water level, the decline in groundwater seepage lines has increased somewhat. The landslide stability coefficient calculated under each working condition is larger than that in the original design, and the decrease rate of reservoir water has a qualitative effect on the stability of the landslide, but the influence is very small. Through the SBAS-InSAR time series monitoring of Sentinel-1 data in the 13th period and field verification, it is found that the cumulative deformation of the slope is small, which prove the stability of the landslide.

A Preliminary Study on the Influencing Factors of Visual Communication of Rural Culture: Based on Grounded Theory

Visual communication has an important impact on revitalizing rural culture, but its implementation still lacks empirical research support. Based on the grounded theory, this study conducted a coding analysis of the data collected in Shuikou Town, Yunyang County, by research method of field investigation. Relevant research shows that: Shuikou Town, Yunyang County, has a positive role in promoting cultural revitalization in terms of content consciousness, villager consciousness, media consciousness, subject environment, and object environment of visual communication. The analysis of the influence mechanism of visual communication on the “consciousness-environment” of rural cultural revitalization from an empirical perspective can also provide a closer look at the current status of rural cultural revitalization to provide a reference for visual communication to promote rural cultural revitalization.

Quantitative Analysis of Spatial–Temporal Differentiation of Rural Settlements Extinction in Mountainous Areas Based on Reclamation Projects: A Case Study of Chongqing, China

Rural settlements in mountainous areas change slowly and are not easy to measure. Reclamation is an important spatial indication of their demise. To measure the spatial–temporal variation of rural settlements extinction from the perspective of regional reclamation projects, and to provide a reference for the scientific evolution of rural settlements in mountainous areas. Based on the data of reclamation projects in Chongqing, China, from 2017 to 2021, with the number of projects, the scale of construction and the scale of newly cultivated land as indicators, coefficient of variation, gravity center model and spatial autocorrelation were used to analyze the distribution characteristics, gravity shift and spatial pattern evolution characteristics of reclamation projects at different spatial scales. The results show that: (1) From the time dimension, the number of reclamation projects, the scale of construction and the scale of newly cultivated land all showed a downward trend, but the differences in the absolute and relative scales of each index gradually decreased, showing a spatiotemporal equilibrium trend. (2) Reclamation projects showed different agglomeration characteristics at different spatial scales. At the regional level, the reclamation projects are concentrated in the city cluster of the Three Gorges reservoir area in Northeast Chongqing. At the district/county level, the reclamation projects are mainly concentrated in Fengjie County (458), followed by Yunyang County (330) and Pengshui County (305), and the least is Wansheng District (32) with an average of about 165. (3) All the centers of gravity in the moving track of the reclamation project center of gravity are located in the city cluster of the Three Gorges reservoir area in northeast Chongqing, and the spatial distribution is geographically balanced. (4) There is a significant agglomeration in the distribution of reclamation projects at the district and county scales. The high-high agglomeration area was mainly concentrated in the city cluster of the Three Gorges reservoir area in northeast Chongqing, and the low-low agglomeration area was mainly distributed in the city proper of Chongqing. The extinction of rural settlements reclamation is affected by regional nature, economy and society, but the land policy is the main driving force. At the same time, we should carefully treat the counties where the rural settlements are disappearing too fast, so as to avoid the drastic changes in the amount and space of cultivated land associated with them.

Slope stability prediction using ensemble learning techniques: A case study in Yunyang County, Chongqing, China

Slope stability prediction plays a significant role in landslide disaster prevention and mitigation. This study develops an ensemble learning-based method to predict the slope stability by introducing the random forest (RF) and extreme gradient boosting (XGBoost). As an illustration, the proposed approach is applied to the stability prediction of 786 landslide cases in Yunyang County, Chongqing, China. For comparison, the predictive performance of RF, XGBoost, support vector machine (SVM), and logistic regression (LR) is systematically investigated based on the well-established confusion matrix, which contains the known indices of recall rate, precision, and accuracy. Furthermore, the feature importance of the 12 influencing variables is also explored. Results show that the accuracy of the XGBoost and RF for both the training and testing data is superior to that of SVM and LR, revealing the superiority of the ensemble learning models (i.e. XGBoost and RF) in the slope stability prediction of Yunyang County. Among the 12 influencing factors, the profile shape is the most important one. The proposed ensemble learning-based method offers a promising way to rationally capture the slope status. It can be extended to the prediction of slope stability of other landslide-prone areas of interest.

Landslide Susceptibility Research Combining Qualitative Analysis and Quantitative Evaluation: A Case Study of Yunyang County in Chongqing, China

Machine learning-based methods are commonly used for landslide susceptibility mapping. Most of the recent publications focused on quantitative analysis, i.e., improving data processing methods, comparing and perfecting the data-driven model itself, but rarely taking the qualitative aspects of the local landslide occurrences into consideration and the further analysis of the key features was always lacking. This study aims to combine qualitative and quantitative analysis and examine its effect on mapping accuracy; based on the feature importance ranks and the related literature, the key features for identifying landslide/non-landslide points of different sub-zones were further analyzed. Before modeling, the study area Yunyang County, Chongqing City, China, was manually divided into four sub-zones based on the information from geological hazards exploration in Chongqing, including the mechanism of landslide formation and sliding failure and geomorphic unit characteristics. Upon the qualitative analysis basis, five grid searches tuned random forest models (one for the whole region and four for the sub-zones independently) were established by 1654 data points and 20 conditioning features. Compared with the conventional data-driven method, the integrated quantitative evaluation based on the qualitative analysis results showed higher reliability, which not only improved the mapping accuracy but also increased the AUC values of all four sub-models, which were 8.8%, 2.3%, 1.9% and 9.1% higher than that of the parent model. Moreover, the quantitative evaluation based on the qualitative analysis revealed the key factors affecting local landslide formation. Therefore, qualitative analysis is recommended in future landslide susceptibility modeling with the additional combination of data-driven methods.

Identification and Evaluation of Water Pollution Risk in the Chongqing Section of the Three Gorges Reservoir Area in China

The Three Gorges Reservoir is the largest freshwater resource reservoir in China. The water environment security in the Three Gorges Reservoir area has a prominent position in the major national strategy for the protection of the Yangtze River. Based on the pressure–state–response (PSR) model, this study comprehensively considers the dangerousness of risk source, the sensitivity of risk receptors, and the acceptable level of regional environmental risk to construct the grading evaluation index system of water environment pollution risk. By using spatial statistical methods, including the variation coefficient method and cold–hot spot pattern analysis, the risk distribution of water environment pollution in the Chongqing section of the Three Gorges Reservoir area was comprehensively identified and evaluated by administrative units. The results showed that: (1) the number of risk sources was largest in Yunyang County and the number of risk receptors was largest in Wanzhou District. However, the distribution of high-risk pollution sources and high-sensitivity receptors was most intensive in the main urban area and surrounding areas of Chongqing, and the regional environmental risk acceptance level was the lowest. (2) The statistical results of risk source dangerousness and the risk receptor sensitivity index at the county level in the study area showed an aggregated distribution pattern, with hotspot areas concentrated in the main urban area of Chongqing and the surrounding area in the upper reaches of the reservoir area. Moreover, the acceptable level of risk in this area showed a cold spot area, while other regions basically showed a balanced distribution pattern without forming significant hot spot or cold spot areas. (3) The high-risk river section of water pollution in the reservoir area comprised five counties, including Jiulongpo District, Yubei District, Shapingba District, Yuzhong District and Nanan District; the middle-risk river section comprised six counties, including Changshou District, Beipei District, Jiangbei District, Dadukou District, Fuling District and Shizhu County; and the low-risk river sections were mainly distributed in the Jiangjin District in the upper reaches of the reservoir area and the middle and lower reaches of the northeast ecological area of Chongqing. Therefore, the acceptable levels of water pollution risk sources, receptors and regional environmental risks in the Chongqing section of the Three Gorges Reservoir area are unevenly distributed, showing an aggregated distribution pattern. The spatial distribution of water environment pollution risk is uneven, and the significant potential risk area is the functional core area of Chongqing, which is the critical area of water environment risk management in the future.

Pathological ribs in sauropod dinosaurs from the Middle Jurassic of Yunyang, Chongqing, Southwestern China

ABSTRACT Palaeopathological analyses have great potential to provide insights into dinosaurs’ palaeobiology and life histories, but few cases have been reported in China. In this study, we report on four pathological sauropod ribs excavated in the same quarry of the Middle Jurassic in Yunyang County, Chongqing, southwest China. Based on morphological observation, computerised tomography (CT)-based energy spectrum data, and image analyses, three types of pathology were identified: traumatic fracture, fracture after bone infection, and osteosclerosis. This study increases the knowledge of dinosaur pathology, especially of Jurassic sauropods, and highlights the use of energy spectrum CT in palaeopathological studies.

The spatial–temporal variation of poverty determinants

Poverty affects many people worldwide and varies in space and time, although its determinants are geographical factors. This paper presents a case study from Hubei Province, Central China, investigating the spatial and temporal changes in poverty determinants at the county from 2013-2019 and village levels from 2013 to 2017. We investigated the variation in the spatial autocorrelation of poverty incidence at the two levels using global and local Moran’s I. We then explored the spatial and temporal variations of poverty determinants using the Lineman, Merenda, and Gold method. We found that the overall spatial autocorrelation gradually mitigated, whereas the local spatial pattern remained unchanged at both levels. Deeply poor areas were concentrated in the western part of Hubei Province and the southwestern part of Yunyang County. The effects of geographical conditions on poverty decreased across the study period, with the R2 value decreasing from 85% to 73% at the county level and from 57% to 38% at the village level. Furthermore, the contribution of natural environmental factors to poverty slightly decreased at both scale levels, whereas the socioeconomic factors had a significantly increased effect on county-level poverty over time. By contrast, the factors that have a major effect on village-level poverty remained stable. The results might indicate that the implementation of various targeted poverty alleviation measures since 2013 have mitigated the restrictions of local geographical factors on poverty alleviation.

Village-level poverty identification using machine learning, high-resolution images, and geospatial data

Tracking progress in poverty alleviation and promptly identifying the distribution of poor areas are critical for strategic policy interventions, especially for regions with poor statistical systems. The massive satellite imagery and geospatial data provide great opportunities for timely and cost-effective socioeconomic evaluations. However, existing research on poverty identification is mostly based on satellite images, and the potential of combined multi-source geospatial data on poverty identification has not been fully explored. Here, we propose an approach that evaluates how village-level poverty can be identified by integrating high-resolution imagery (HRI), point-of-interest (POI), OpenStreetMap (OSM), and digital surface model (DSM) data. The study area included 338 villages from Yunyang County, located in Hubei Province, central China. We extracted the explanatory variables indicating access to facilities and services, agricultural production conditions, village construction, and the spatial distribution of village settlements from the HRI, POI, OSM, and DSM data. The random forest algorithm was then used to model the relationship between village-level poverty and explanatory variables. The results demonstrated a 54% accuracy in the prediction of village-level poverty; the best prediction performance (72%) was observed for the villages categorized as poor. The built-up land proportion and the time cost to the facilities and services contributed the most to the identification of village-level poverty, while the proxy variables of agricultural production conditions contributed the least. This study provides an approach to village-level poverty identification using satellite imagery and geospatial data and proves that the data employed in this study could identify the poorest areas that are highly coupled with natural geographical conditions and backward public services.

Assessment of the Suitability of Wintering Anatidae Habitats before and after Impoundment in the Three Gorges Reservoir Region

In this study, we aimed to understand the distribution of and changes in the habitats suitable for Anatidae wintering in the Three Gorges Reservoir Region (TGRR), China, and to explore the impact of the impoundment during different impoundment periods. Based on species occurrence data for four dominant species of Anatidae and environmental factors, a maximum entropy (MaxEnt) model was used to analyze the suitability of habitats during five impoundment periods. The results show that the main factors affecting Anatidae distribution were temperature and roads before the Three Gorges Project (TGP) and elevation after the TGP. After the TGP, the area of the suitable habitat declined rapidly and then gradually increased with increasing water level. After impoundment, the primary area of increased habitat suitability was the main stream of the Yangtze River from Changshou District to Yunyang County and its tributary in the Kaizhou area. Among the habitats, the central water regions were more suitable than the marginal shoal areas. Anatidae habitats in the TGRR were distributed mainly within the Yangtze River main stream and the surrounding areas before the TGP, and the surrounding areas largely disappeared after the TGP, particularly in Chongqing City and Jiangjin District. In this context, it is challenging to create new protected areas within the habitat suitable for Anatidae in the main stream of the Yangtze River; we propose adding the Anatidae as conservation targets within the existing conservation agencies and implementing a waterbird monitoring program for scientific waterbird conservation and the sustainable development of the reservoir.

New freshwater plesiosaurian materials from the Middle Jurassic Xintiangou Formation of the Sichuan Basin, southwestern China

Sichuan Basin is very famous for the Mesozoic reptiles, especially the Jurassic dinosaurs. Here, we report some isolated plesiosaurian teeth and vertebrae newly excavated from the Middle Jurassic Xintiangou Formation in Yunyang county, Chongqing City, the northeastern region of the Sichuan Basin, southwestern China. The specimens are referred to Pliosauroidea based on the combination of the following features: the circular cross-section of the tooth crown, apicobasal ridges fully covering the enamel surface and reaching to the apex, the short and amphicoelous centrum, the centrum shorter than wide or tall, and the absence of a keel on the lateral surface of the cervical centrum. With the fragmentary nature, it is undetermined whether the Yunyang specimens belong to a known taxon or represent a new species of Plesiosauria. These plesiosaurian specimens further demonstrate that the freshwater plesiosaurians are common in the Jurassic deposits of the Sichuan Basin. For a comprehensive knowledge of the plesiosaurians of the basin in origin, distribution and diversity, to discover new and more complete specimens is necessarily the first priority.

Analysis of ecological carrying capacity using a fuzzy comprehensive evaluation method

Abstract With the rapid development of the economy, environmental issues have become increasingly prominent and pose a threat to the sustainable development of human society. Maintaining the integrity of ecosystems and limiting human activity are prerequisites for sustainable economic development. Therefore, fully understanding the regional ecological conditions and related influential factors is important for promoting regional sustainable development. It is of great practical significance to study the ecological carrying capacity (ECC) from multiple perspectives. In this paper, Shannon entropy theory, a fuzzy comprehensive method and an analytic hierarchy process (AHP) are used to provide reasonable weights for ECC evaluation modelling by combining subjective and objective weights. Furthermore, based on ecological resilience and ecological pressure, a comprehensive system of evaluation factors is established for ECC assessments. For this study in Yunyang County in the Three Gorges Reservoir area of China, the following fifteen factors were selected: slope, land use, the land stress index, the habitat quality index, the water network density index, vegetation coverage, the geological hazard index, annual total rainfall, annual total temperature, the population density index, the proportion of construction land, the economic development index, the road network density index, the steep slope reclamation rate and the proportion of agricultural land. Additionally, an obstacle degree model was used to explore the response relationship between the regional ecological quality and the corresponding influential factors and to extract the major factors that affect the quality of the ecological environment. The results show that the area with a very low comprehensive evaluation rating is 119.54 km2, accounting for 3.30% of the study area, including Bayang Town, Shuangjiang Street and Qinglong Street, and the area with a low comprehensive evaluation rating is 519.29 km2, accounting for 14.34% of the study area. The main factor that influences the environmental quality of the study area is the economic development index, and the obstacle degree frequency is higher than 80%. Additionally, the steep slope reclamation rate, land stress index and proportion of agricultural land also have considerable impacts on the ECC of Yunyang County, with obstacle degree frequencies of 61.90%, 61.90% and 52.38%, respectively.

NUMERICAL MODELLING OF COOPERATIVE AND NONCOOPERATIVE THREE TRANSBOUNDARY POLLUTION PROBLEMS UNDER LEARNING BY DOING IN THREE GORGES RESERVOIR AREA

In this paper, we investigate cooperative and noncooperative three transboundary pollution problems in Three Gorges Reservoir Area where emission permits trading and abatement costs under learning by doing are considered. The abatement cost depends on two key factors: the level of pollution abatement and the experience of using pollution abatement technology. We use the optimal control theory to study the optimal emission paths and the optimal pollution abatement strategies under cooperative and noncooperative three transboundary pollution problems, respectively. By using the actual economic data of Wanzhou District, Kaizhou District and Yunyang County, we obtain the abatement level and the pollution stock of cooperative and noncooperative three transboundary pollution problems based on the four order Runge-Kutta method. We also discuss the influence of the change of parameter μi(i = 1,2) for the abatement level and the pollution stock.

Regional Rainfall Warning System for Landslides with Creep Deformation in Three Gorges using a Statistical Black Box Model

Establishing an efficient regional landslide rainfall warning system plays an important role in landslide prevention. To forecast the performance of landslides with creep deformation at a regional scale, a black box model based on statistical analysis was proposed and was applied to Yunyang County in the Three Gorges Reservoir area (TGRA), China. The data samples were selected according to the characteristics of the landslide displacement monitoring data. Then, the rainfall criteria applied to different time periods were determined by correlation analysis between rainfall events and landslides and by numerical simulation on landslide movement under certain rainfall conditions. The cumulative rainfall thresholds that were determined relied on the displacement ratio model, which considered landslide scale characteristics and the statistical relationship between daily rainfall data and monthly displacement data. These thresholds were then applied to a warning system to determine a five-level warning partition of landslides with creep deformation in Yunyang County. Finally, landslide cases and displacement monitoring data were used to validate the accuracy of the model. The validation procedure showed that the warning results of the model fit well with actual conditions and that this model could provide the basis for early warning of landslides with creep deformation.

Epidemiological Characteristics of Varicella in Yunyang County, Chongqing from 2013 to 2017

Epidemiological Characteristics of Varicella in Yunyang County, Chongqing from 2013 to 2017

Epidemiological Characteristics of Hand, Foot, and Mouth Disease in Yunyang County of Chongqing, China, 2012-2016

Epidemiological Characteristics of Hand, Foot, and Mouth Disease in Yunyang County of Chongqing, China, 2012-2016