Search

The deformation and failure of the surrounding rock mass is a key issue during the construction of large‐scale underground powerhouse, and large discontinuities are likely to cause this problem in the presence of complex geological structures. This article takes the right bank underground powerhouse of the Baihetan Hydropower Station as a case study. In this case, deformation mutation of the surrounding rock mass occurred in the south section of the main powerhouse, with the maximum deformation reaching 178 mm, and the deformation and failure of different parts showed differences. A comprehensive study integrating field survey, site monitoring, laboratory test and numerical simulation was carried out. By field survey and monitoring, characteristics of deformation and failure are described, and the spatiotemporal difference in deformation is analysed. The stress evolution during excavation is studied based on numerical simulations, the mechanical response of rock is derived through laboratory tests, and the mechanism of spatiotemporal difference is revealed. The results indicate that the main reason for the spatiotemporal difference is the presence of slightly inclining interlayer shear zone C4. In the south section, the excavation‐induced stress concentration at the arch was enhanced due to C4, with the maximum principal stress exceeding 70 MPa, and the high compressive stress here triggered the deformation mutation of surrounding rock mass. After undergoing a stress path from concentration to unloading, the surrounding rock mass at the downstream sidewall was seriously damaged, and its deformation also mutated under approximately vertical stress. The mutation resulted in the uneven spatial distribution, large increment and time‐dependent feature of deformation. [ABSTRACT FROM AUTHOR]

Architecture is the stone book of history, and the evolution of architectural styles showcases a non-verbal history constructed through images. As an important part of China's historical and cultural heritage, the architectural forms and styles of Tibetan Buddhist temples were initially modeled on Tang dynasty temple architecture and gradually evolved into the most significant architectural types in regions such as Tibet and Qinghai in China. Religious architecture has also played a significant role in shaping regional cultural landscapes. Existing research on Tibetan Buddhist temples is primarily focused on qualitative studies of individual temple buildings. This research takes the spatiotemporal evolution of architectural styles of Tibetan Buddhist temples as an entry point and, for the first time, employs ArcGIS technology to visualize the spatial and geographical distribution of Tibetan Buddhist temples from the 7th to the 18th century, establishing a comprehensive academic vision that encompasses both historical stratification and cross-regional spatial correlations. By analyzing the cultural symbolic features embodied in the construction styles of Tibetan Buddhist temples and the visual characteristics reflected in their decorative arts, we propose two spatiotemporal dimensions for the formation and transmission of Tibetan Buddhist temple architectural styles: "Westward Transmission" and "Eastward Diffusion". Firstly, from the 7th to the 9th centuries, the architectural style and construction techniques of Tang dynasty Buddhist temples were transmitted westward along the Tang–Tibet ancient road, integrating with local Tibetan elements to form the Tubo architectural style, which was further refined into the "Sino–Tibetan Combined Style" with strong visual characteristics around the 13th century. Subsequently, along with the spread of Tibetan Buddhism, this temple architectural style underwent an eastward diffusion from the 13th to the 18th century, reaching regions, such as Sichuan, Qinghai, Gansu, Inner Mongolia, Hebei, and Beijing, presenting a spatial gradient from west to east in the geographical dimension. On this basis, in this research, we construct a historical evolution mapping of Tibetan Buddhist temple architectural styles based on bidirectional transmission, attempting to elucidate that the intrinsic driving forces are religious and the cultural identity that guided the bidirectional transmission mechanism of these architectural styles under the historical context of the formation and dissemination of Tibetan Buddhism from the 7th to the 18th century. [ABSTRACT FROM AUTHOR]

[Objective] The study aimed to refine the types of cultivated land use, explore the spatial and temporal evolution patterns of cultivated land use types and their driving mechanisms, and provide a reference for optimizing the utilization of cultivated land resources and ensuring national food security. [Method] Based on the state of cultivated land use, farmland in Guanglong province was categorized into three types: paddy fields, dry land and croplund abandonment. Employing multiple methods such as the dynamic degree of land use, standard ellipse deviation model and geographical detectors, the study examined the spatiotemporal changes of long-term cultivated land use types in Guangdong province from three perspectives: time, space and structure. It explored the spatiotemporal evolution patterns and the underlying driving mechanisms, aiming to clarify the changing churacteristics of different types of cultivated land use. [Result] (i) Over the past 30 years, the types of cultivated land use in Guangdong province underwent significant changes in their spatiotemporal distribution and internal structure. Paddy fielda, dry land and cropland abandonment lemonstrated apatial agglomeration characteristics, primarily concentrated in areas with extensive cultivated land distribution but less developed economies, such as the Leizhou Peninsula hilly platform in western Guangdong, the southwestern Guangdong hills, and the central and southern Guangdong hills. The centroid of cultivated land exhibited a U-shaped migration trajectory, moving southwestward overall. (ii) The most significant changes were the conversion of dry land to paddy fields and dry land to cropland abandonment. These changes predominantly clustered in the southwestern Guangdong hills and the Leizhou Peninsula hilly platform, regions with extensive cultivated land distribution but underdeveloped economies. (iii) The area changes in cultivated land use types in Guangdong province were based on the natural environment and influenced by social, economic, and agricultural development factors. The primary driving factors for the area changes of the three types of cultivated land use were the amount of chemical fertilizer applied, the amount of pesticide used, and the labor force in the primary industry. Economic and agricultural factors such as agricultural gross output value, agricultural gross output value per capita, added value of the primary industry, cultivated land area per capita, grain yield, and total power of agricultural machinery have shown an increasing drive for changes in the areas of paddy fields, dry land, and fallow land year by year. (Conclusion] The spatiotemporal distribution, land type conversion, and driving mechanisms of paddy fields, dryland, and cropland abandonment in Guangdong province have formed distinct evolutionary patterns. The optimization and reconstruction of cultivated land resources should be carried out based on the differentiation patterns of cultivated land use types. [ABSTRACT FROM AUTHOR]

In the southern Sichuan Basin of China (SSBC), hydraulic fracturing (HF) production of shale gas and surface buildings have been seriously affected by some medium scale (local magnitude ML > 4.0) earthquake events. In this study, focusing on relocated hypocenters in SSBC from January 2016 to May 2017, the Density-Based Spatial Clustering of Applications with Noise algorithm was introduced to divide it into four seismic regions. The temporal evolution of seismicity parameters, detailed views of potential faults near injection wells and spatial migration of seismic activity in each region were obtained. Moreover, the statistical correlation between seismicity and engineering disturbance was calculated by adopting epidemic type aftershock sequence model (ETAS); the relationship between corner frequency, stress drop and seismic moment of each region were analyzed, and the spatial distribution of the stress drop, the relationship with the focal mechanism solutions (ML > 3.5) and the fault slip-tendency under the regional stress pattern were discussed. The results show that the seismic diffusion rate of each region can be well described by the square root envelope (0.3–0.8 m2/s) and seismicity has a strong cluster mode (triggered events) and a weak background mode (independent events). Most (more than 97.5%) of the stress drops are in the range of 0.1–10 MPa, and the high stress drops is mainly located in the YS108 shale block; under the current regional stress pattern, the faults in region YS108 are unfavorablely oriented, while those in the south of N201 are favorablely oriented, with a high sliding trend. This knowledge may provide time to take mitigating actions to reduce the potential for damaging earthquakes. Highlights: Spatial clustering in SSBC based on DBSCAN algorithm and the relocated hypocenters associated with hydraulic fracturing, and the spatiotemporal migration characteristics are analyzed. Focal mechanisms indicate different fault planes, matching well with relocated hypocenters Statistical relationship between source parameters (corner frequency, stress drop, seismic moment, etc.) and regional variations Discuss the slip-tendency of potential faults in various regions under inversion of current stress pattern [ABSTRACT FROM AUTHOR]

The Yellow River Basin of China is a key region that contains myriad interactions between human activities and natural environment. Industrialization and urbanization promote social-economic development, but they also have generated a series of environmental and ecological issues in this basin. Previous researches have evaluated urban resilience at the national, regional, urban agglomeration, city, and prefecture levels, but not at the watershed level. To address this research gap and elevate the Yellow River Basin's urban resilience level, we constructed an urban resilience evaluation index system from five dimensions: industrial resilience, social resilience, environmental resilience, technological resilience, and organizational resilience. The entropy weight method was used to comprehensively evaluate urban resilience in the Yellow River Basin. The exploratory spatial data analysis method was employed to study the spatiotemporal differences in urban resilience in the Yellow River Basin in 2010, 2015, and 2020. Furthermore, the grey correlation analysis method was utilized to explore the influencing factors of these differences. The results of this study are as follows: (1) the overall level of urban resilience in the Yellow River Basin was relatively low but showed an increasing trend during 2010-2015, and significant spatial distribution differences were observed, with a higher resilience level in the eastern region and a low-medium resilience level in the western region; (2) the differences in urban resilience were noticeable, with industrial resilience and social resilience being relatively highly developed, whereas organizational resilience and environmental resilience were relatively weak; and (3) the correlation ranking of resilience influencing factors was as follows: science and technology level>administrative power>openness>market forces. This research can provide a basis for improving the resilience level of cities in the Yellow River Basin and contribute to the high-quality development of the region. [ABSTRACT FROM AUTHOR]

Copyright of China Rural Water & Hydropower is the property of China Rural Water & Hydropower Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Resources Development & Market is the property of Sichuan Resource Development & Market Magazine Co., Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Land use change stands as the primary factor influencing habitat quality (HQ). Clarifying the spatiotemporal change and the obstacle factors of the coupling relationship between HQ and urbanization level (UL) can provide imperative references for achieving sustainability in the Yellow River Basin (YRB). This study is based on the InVEST model, spatial autocorrelation, and obstacle factor analysis to measure the spatiotemporal dynamics and impediments of the coupling relationship between HQ and UL from 2000 to 2020 in the YRB. The findings were as follows: (1) From 2000 to 2020, the HQ showed a tendency of rise first and then fall, with the pattern of "High in the middle and west, low in the east"; (2) from 2000 to 2020, the UL had an upward trend, with the pattern of "Low in the west, high in the middle and east"; (3) the coupling and coordination level of HQ and UL in the YRB changed from extreme incoordination to verge of coordination, and it had a distribution pattern of "High in the east, low in the west", with the high-value area expanding to the east and the low-value area shrinking to the west. (4) Location condition, climate, proportion of construction land, vegetation index, and proportion of non-agricultural employment are the main obstacle factors that determined the coupling and coordination of the HQ and UL. [ABSTRACT FROM AUTHOR]

Tourism is a strategic pillar industry of the national economy, playing a role in cultural prosperity, national unity and stabilizing the border. Border ethnic areas in western China are rich in cultural and tourism resources, and promoting the high-quality development of cultural and tourism integration is an important hand in promoting the interaction, communication and integration of various ethnic groups and casting a firm sense of Chinese national community. Taking the border ethnic areas as the research object, based on the multi-indicator panel data from 2011 to 2020, we measure the level of high-quality development of culture and tourism, analyze the spatiotemporal evolution of the coordination degree, and identify the driving factors. The study found that: (1) The level of high-quality development of culture and tourism in the border ethnic areas is generally on the rise, the impact of the new crown epidemic on tourism is obvious in 2020, and the level of high-quality development of culture is higher than the level of high-quality development of tourism due to the influence of historical and cultural precipitation and cultural exchanges. (2) The degree of coordination of high-quality development of cultural and tourism integration in all provinces and regions is rising in fluctuation, and the level of coordination is gradually optimized. The coordination level of high- quality development of cultural and tourism integration is higher in Guangxi and Yunnan, forming the "Matthew effect". (3) The investment level, policy support, market supply and transportation conditions are the important driving force for the high-quality development of cultural and tourism integration in the border ethnic areas, among which the investment level shows the strongest utility. The results of the study provide theoretical basis and data support for the high-quality development of culture and tourism integration in border ethnic areas, which can help strengthen the construction of cultural tourism, realize the transformation and upgrading of tourism, and enhance the vitality and influence of culture. [ABSTRACT FROM AUTHOR]

The harmonized development of water resources and cities is of great importance for the high-quality development of regions and water security. Study of water ecological footprint (WEF) has important theoretical and practical significance for the sustainable utilization of water resources. This study utilizes an improved WEF model and panel data from Chinese super-megacities to analyze the spatiotemporal evolution characteristics and variation trends of the WEF through the application of kernel density estimation, variable coefficient model and gray neural network model. The research findings are as follows. (1) The WEF per capita of 21 super-megacities shows significant variations from 2003 to 2020, along with large inter-annual fluctuations. This disparity seems to be widening spatially. The regions with the highest WEF per capita are concentrated in 12 cities, where the annual average value exceeded 0.006 hm 2 ∕ cap. Besides, these super-megacities are predominantly located in the northeast. The water ecological carrying capacity (WEC) of super-megacities reflects the supply capability of water resources and is declining during the study period, with an average multiyear decline rate of 1.2%, highlighting the urgent need to enhance water production capacity. (2) Seventeen super-megacities are experiencing water resource ecological deficits and severe ecological imbalances, with the deficit primarily concentrated in the northeastern region. According to sustainability evaluation indicators, water resources in 13 super-megacities are undergoing unsustainable development, particularly with Beijing, Tianjin and Zhengzhou reaching Level I and being in a moderately unsustainable state. Research has shown that the sustainable utilization of water resources is more advanced in southern regions compared to northern regions. (3) Economic development, industrial structure, technology level and environmental regulations have a significant differentiated effect on WEF per capita across various city levels. (4) The prediction results of the gray neural network demonstrate a decrease in the WEF per capita of seven representative super-megacities from 2023 to 2027, showing significant variations across different regions. [ABSTRACT FROM AUTHOR]

The Yellow River water recharge area in Gannan is an important ecological barrier in the upper reaches of the Yellow River. The stable provision of ecosystem services is essential for the sustainable development of the Yellow River Basin. Based on land-use changes from 2000 to 2020, the equivalence factor is corrected by combining net primary productivity (NPP) data and socio-economic factors, the ecosystem services value (ESV) of the study area is calculated for five periods. Through methods such as spatial autocorrelation and centroid model, this study investigates the spatio-temporal evolution characteristics and spatial heterogeneity of ESV from 2000 to 2020. The results show that from 2000 to 2020, the land use/cover change (LUCC) types in the Yellow River water recharge area of Gannan were mainly grassland, woodland and cultivated land. The areas of grassland, woodland, construction land, and waters have increased, while cultivated land has decreased by 448.57 km² at a rate of change of 19%. From 2000 to 2020, the average ESV was 408.785 1 x 108 yuan. The main focus was on regulation services, with hydrological regulation and climate regulation accounting for about 48.69% of the total ESV. Grassland and woodland made the greatest contribution to ESV and are key land types for the total value of ecosystem services. The size of the water area continued to increase, affecting the rise in ESV for water production services, with a cumulative increase of 3.401 3%. Land-averaged ESV showed a strong positive spatial correlation, and spatial clustering was generally stable. The spatial distribution of woodland had an important influence on the spatial pattern of ESV, with areas of higher ESV overlapping with areas of concentrated woodland, while areas of lower ESV were dominated by construction and cultivated land. The research results reveal the spatio-temporal pattern evolution of ESV in the Yellow River water recharge area of Gannan under the background of LUCC changes. The results can provide a basis for spatial planning, economic development, ecological environmental protection and management in the region, contributing to the high-quality development of the basin. [ABSTRACT FROM AUTHOR]

PurposeThe purpose of this paper is to measure the dietary diversity and to analyze the regional characteristics, differences, and evolutionary trends of dietary diversity among Chinese residents.MethodsIn this paper, the dietary diversity among Chinese residents was measured using the Shannon index based on the provincial-level food consumption data from 1995 to 2021. On this basis, the paper employs analysis methods such as kernel density estimation, spatial correlation test, and Dagum’s Gini coefficient to analyze the regional characteristics, differences, and trends of change in dietary diversity.ResultsDuring the study period, the dietary diversity among Chinese residents showed an increasing trend. Among the four major geographic regions, the dietary diversity was highest in the southern region, followed by the northern region, northwest region, and Qinghai-Tibet region. Among the three major economic regions, the dietary diversity was highest in the eastern region, followed by the central region and western region. There was a significant positive spatial correlation in the dietary diversity among Chinese residents, and both high-high agglomeration and low-low agglomeration phenomena were strengthened. In terms of the trend of regional differences, whether overall differences, interregional differences, or intraregional differences, they all showed a shrinking trend. However, interregional differences were the main source of overall differences in dietary diversity among Chinese residents.ConclusionThe dietary diversity among Chinese residents shows an overall increasing trend, and there are regional differences in dietary diversity from the perspectives of economic and geographic regions, which have been narrowing over time.

Digital economy, as an innovative digital technology, can promote environmental governance and support low-carbon development. Under the backdrop of China's dual carbon strategy, the country faces significant challenges in achieving coordinated development across the domains of economy, environment, and energy. Based on panel data from 30 Chinese provinces between 2012 and 2022, this paper constructs a coupling coordination model to measure the level of integrated development among digital economy, environmental regulation, and carbon emission intensity. The study also examines the spatiotemporal evolution of this coordination using kernel density estimation and spatial correlation tests. Furthermore, empirical analysis via regression models was employed to investigate key influencing factors. The findings suggest that: (1) The coupling coordination level has shown an upward trend over the sample period, with no extreme regional disparities; (2) Spatially, the development of coupling coordination exhibits “high-high” and “low-low” clustering effects; (3) Development levels are influenced by various external driving factors, with significant regional differences in primary influencing factors. For these findings, the following recommendations are proposed: enhance digital infrastructure, optimize regulatory frameworks, and promote the integration of digital economy with green and low-carbon development.

Study region: The Hanjiang River Basin, China. Study focus: In this study, we proposed a new integrated framework based on structural equation models to identify hydrometeorological multi-factor interaction relationship. The spatiotemporal distribution and interaction relationship of hydrological, meteorological, and vegetation indicators in the Hanjiang River Basin were analyzed based on the national long-series monitoring data. New hydrological insights for the region: The findings reveal that: (1) The rainfall is the maximum in the lower reaches (968.87 mm), and the runoff depth fluctuated the most in the lower reaches (1181.70 mm to 2934.88 mm). (2) Dew point temperature is an important influencing factor of rainfall in the upper and middle reaches, and relative humidity is an important influencing factor of rainfall in the lower reaches. High vegetation cover is an important influencing factor for runoff depth. (3) Rainfall and runoff depth are significantly negatively affected by meteorological characteristics, with effect values ranging from −0.24 to −0.68. However, runoff depth is positively affected by rainfall, relative humidity, vegetation characteristics, and canopy interception, with effect values ranging from 0.02 to 0.58. The size and mode of influence have significant regional differences.

Study region: Swat district, Khyber Pakhtunkhwa (KPK) Province, Pakistan. Study focus: With the rise of social-media data, there is an increasing need to promptly and precisely identify content related to disasters, such as urban waterlogging. Social-media data, being cost-effective and abundant, can offer valuable insights into geographic phenomena by analyzing human behavioral patterns, making it a powerful resource for detailed waterlogging (WLG) analysis in urban settings. Innovative insights: This research introduces a novel framework for precise information retrieval and real-time extraction of WLG points and fine-grained information in disaster-affected areas using the Facebook platform. First, topic modeling and transfer learning techniques were developed to examine the spatiotemporal dynamics of WLG locations. Second, water depth data from textual content and visual representations were extracted using various deep learning frameworks and integrated through decision-making processes. Third, a unique fine-grained location corpus tailored to urban flooding scenarios was created using the named entity recognition (NER) model. Finally, the BERT-BiLSTM-CRF model was employed to extract WLG points accurately. Using the Swat district as a case study, the extracted WLG points covered at least 79 % of the officially documented WLG points and were primarily located near roadways, especially in low-elevation areas. This framework provides a viable approach for enhancing situational awareness and conducting spatiotemporal analysis of urban floods and WLG disasters at the municipal level in real-time.

Abstract The layering process of the historic urban landscape (HUL) has spatial and temporal characteristics. With the help of digital technology, building a database to collect and manage spatial information on HUL is an effective research method. Taking Nanjing since the Ming Dynasty (1368–2024) as an example, our paper proposes a framework for constructing a historical geographic information system (HGIS) for HUL. The results show that (1) ancient Chinese historical archives have good potential for use in the construction of historical landscape databases. The HGIS can visualize the evolution of HUL and realize the storage, expression, querying, and analysis of information in different formats. (2) The Republic of China is a turning point in the evolution of Nanjing’s HUL. In terms of spatial evolution, the main distribution areas of urban form and characteristic places, as well as the NACH (normalized angular choice) and NAIN (normalized angular integration) cores of the road network, all moved from the south to the north of the city. In terms of typological evolution, the urban form changes from a predominantly residential area to one that emphasizes residential, administrative, educational and industrial areas. The main types of characteristic places shifted from house gardens, temples and ancestral halls to scenic buildings and public gardens. (3) Political factors, urban planning, commercial ports, and land prices influence the layering process of the HUL. The constructed database guides the preservation of HUL from the digital heritage perspective and the construction of other historical databases with spatial characteristics.

[Objective] The ecological environment of the Kuye River Basin plays a critical role in the larger context of the Yellow River Basin’s health. Understanding the ecosystem services it provides is crucial for sustainable development. [Methods] Using the InVEST model, researchers conducted a quantitative assessment of ecosystem service functions from 1990 to 2020. [Results] (1) There have been some notable changes in land management policy leading to shifts in land use patterns, particularly in construction land expansion and decreased unused land. Additionally, it seems like there’s been a positive impact on vegetation cover, with grassland dominating and overall vegetation coverage showing an upward trend, albeit with fluctuations. (2) The ecological service function of the Kuye River Basin showed a trend of first declining around 2000 and then fluctuating and increasing after 2010, and the habitat quality index was basically stable between 0.22~0.24, and the overall habitat quality was poor. (3) The soil conservation and habitat quality index in the watershed was dominated by the distribution of low-low aggregation cold spots, the spatial distribution of carbon storage and water conservation cold spots and hot spots was relatively scattered, and the high and low values were spatially staggered. The soil conservation and habitat quality index were mainly low-value aggregation, and the spatial distribution of carbon storage and water conservation was fragmented. (4) In the past 30 years, carbon storage and habitat quality were mainly affected by land use, and soil conservation and water conservation were mainly affected by topography, soil type and precipitation. [Conclusion] The findings of this study highlight the intricate interplay between land use, topography, soil type, precipitation, and their impacts on carbon storage, habitat quality, soil conservation, and water conservation in the Kuye River Basin. Understanding these dynamics is crucial for devising effective strategies to enhance ecological services and allocate appropriate soil and water conservation measures.

[Objective] This research aims to explore the temporal and spatial status of the ecological quality evolution and the main driving factors of its evolution in the Loess Plateau, and to provide the theoretical basis for the improvement of regional ecological quality and sustainable development in the Yellow River Basin. Methods] Based on the 'Driving Force-Pressure-State-Impact-Response' (DPSIR) model, 14 indexes reflecting the social and economic situations, natural environment and ecological governance were selected to build the comprehensive evaluation index system. The weight of each index was defined by the analytical hierarchy process (AHP), and the comprehensive evaluation indexes were calculated by the weighted average. The Ridge Regression Model was used to quantitively assess the driving factors of the ecological quality evolution. [Results] The ecological quality of the Loess Plateau in the Yellow River Basin exhibited a distinctive spatiotemporal heterogeneity, with the high-quality areas concentrating in the midstream and low quality areas in the upstream, showing the unique spatial pattern of high-quality in the southeast and low- quality in the northwest'. The medium-quality areas and above increased from 40.56% in 2000 to 70.36% in 2020. The ecologically improved areas in the past 2 decades took up 94.44% of the total research area, and the ecologically improved counties accounted for 91.57% of the total counties. The Ridge Regression Model explained 99.4% of the ecological evolution, demonstrating the relatively higher contributions from the vegetative cover and the annual precipitation to such evolution. [Conclusion] The ecological quality in the Loess Plateau was improved, and the spatiotemporal evolution of ecological quality was mainly driven by vegetative cover and annual precipitation. It is recommended that the spatial pattern of ecosystems is further optimized on the basis of a scientific and rational increase in vegetation cover. [ABSTRACT FROM AUTHOR]

[Objective] This study aims to analyze the spatiotemporal dynamic evolution characteristics and driving mechanisms of impervious surfaces in the central Yunnan urban agglomeration, and to provide a theoretical basis for related research and assisting government and relevant departments in formulating urban agglomeration planning and development strategies, [Methods] GISD 30-meter impervious surface data from the central Yunnan urban agglomeration for the years 2000 to 2020 were utilized. Spatial analysis methods such as dynamic degree, standard deviation ellipse, quadrant analysis, and geographical detector were employed to reveal the spatiotemporal patterns of impervious surface changes and their driving mechanisms. [Results] (1) With respect to temporal scale evolution, over the past two decades, the overall expansion rate of impervious surfaces in the central Yunnan urban agglomeration exhibited a fluctuating trend characterized by decline-rise-decline, with an annual average expansion rate of 66.77 km². The annual average dynamic degree reached to 4.36%, indicating a continuous decline in the dynamism of impervious surfaces. The impervious surface area in the urban agglomeration expanded by 1 402.2 km² during this period, with a growth rate of 91.5%. (2) With respect to spatial scale evolution, the expansion of impervious surfaces within various cities of the central Yunnan urban agglomeration over the last two decades displayed significant spatial disparities. For instance. Kunming witnessed substantial expansion of impervious surfaces. while Chuxiong Prefecture exhibited comparatively minimal expansion. On the whole, the urban. agglomeration expanded towards the southern and southeastern directions, with the migration center remaining relatively stable, (3) With respect to directionality, the expansion of impervious surfaces in the central Yunnan urban agglomeration over the past 20 years showed a clear directional trend. primarily expanding in the northeast to southwest direction. The largest standard deviation ellipse area in year 2005 was marked, signifying the onset of rapid impervious surface expansion. Over the 20-year period, the center of impervious surface expansion remained relatively stable consistently shifting southward with relatively minor overall changes. (4) Analysis of driving mechanisms indicated that population factors had a significant impact on impervious surface expansion, whereas factors such as LAI, slope, precipitation, temperature. and NDVI had less significant effects. The interaction strength between population and other factors was notably stronger than that between other factors. Conclusion Over the past two decades, impervious surfaces in the central Yunnan urban agglomeration had continued to expand, exerting a significant influence on the resource and environmental carrying capacity of the urban agglomeration and the spatial land use pattern. To support the high-quality leapfrog development of the central Yunnan urban agglomeration, an emphasis on optimizing the spatial layout of impervious surfaces is crucial. [ABSTRACT FROM AUTHOR]

There are significant differences between urban and rural bed-and-breakfasts (B&Bs) in terms of customer positioning, economic strength and spatial carrier. Accurately identifying the differences in spatial characteristics and influencing factors of each type, is essential for creating urban and rural B&B agglomeration areas. This study used density-based spatial clustering of applications with noise (DBSCAN) and the multi-scale geographically weighted regression (MGWR) model to explore similarities and differences in the spatial distribution patterns and influencing factors for urban and rural B&Bs on the Jiaodong Peninsula of China from 2010 to 2022. The results showed that: 1) both urban and rural B&Bs in Jiaodong Peninsula went through three stages: a slow start from 2010 to 2015, rapid development from 2015 to 2019, and hindered development from 2019 to 2022. However, urban B&Bs demonstrated a higher development speed and agglomeration intensity, leading to an increasingly evident trend of uneven development between the two sectors. 2) The clustering scale of both urban and rural B&Bs continued to expand in terms of quantity and volume. Urban B&B clusters characterized by a limited number, but a higher likelihood of transitioning from low-level to high-level clusters. While the number of rural B&B clusters steadily increased over time, their clustering scale was comparatively lower than that of urban B&Bs, and they lacked the presence of high-level clustering. 3) In terms of development direction, urban B&B clusters exhibited a relatively stable pattern and evolved into high-level clustering centers within the main urban areas. Conversely, rural B&Bs exhibited a more pronounced spatial diffusion effect, with clusters showing a trend of multi-center development along the coastline. 4) Transport emerged as a common influencing factor for both urban and rural B&Bs, with the density of road network having the strongest explanatory power for their spatial distribution. In terms of differences, population agglomeration had a positive impact on the distribution of urban B&Bs and a negative effect on the distribution of rural B&Bs. Rural B&Bs clustering was more influenced by tourism resources compared with urban B&Bs, but increasing tourist stay duration remains an urgent issue to be addressed. The findings of this study could provide a more precise basis for government planning and management of urban and rural B&B agglomeration areas. [ABSTRACT FROM AUTHOR]

The layering process of the historic urban landscape (HUL) has spatial and temporal characteristics. With the help of digital technology, building a database to collect and manage spatial information on HUL is an effective research method. Taking Nanjing since the Ming Dynasty (1368–2024) as an example, our paper proposes a framework for constructing a historical geographic information system (HGIS) for HUL. The results show that (1) ancient Chinese historical archives have good potential for use in the construction of historical landscape databases. The HGIS can visualize the evolution of HUL and realize the storage, expression, querying, and analysis of information in different formats. (2) The Republic of China is a turning point in the evolution of Nanjing's HUL. In terms of spatial evolution, the main distribution areas of urban form and characteristic places, as well as the NACH (normalized angular choice) and NAIN (normalized angular integration) cores of the road network, all moved from the south to the north of the city. In terms of typological evolution, the urban form changes from a predominantly residential area to one that emphasizes residential, administrative, educational and industrial areas. The main types of characteristic places shifted from house gardens, temples and ancestral halls to scenic buildings and public gardens. (3) Political factors, urban planning, commercial ports, and land prices influence the layering process of the HUL. The constructed database guides the preservation of HUL from the digital heritage perspective and the construction of other historical databases with spatial characteristics. [ABSTRACT FROM AUTHOR]

The Chaobai River Basin, which is a crucial ecological barrier and primary water source area within the Beijing–Tianjin–Hebei region, possesses substantial ecological significance. The gross ecosystem product (GEP) in the Chaobai River Basin is a reflection of ecosystem conditions and quantifies nature's contributions to humanity, which provides a basis for basin ecosystem service management and decision-making. This study investigated the spatiotemporal evolution of GEP in the upper Chaobai River Basin and explored the driving factors influencing GEP spatial differentiation. Ecosystem patterns from 2005 to 2020 were analyzed, and GEP was calculated for 2005, 2010, 2015, and 2020. The driving factors influencing GEP spatial differentiation were identified using the optimal parameter-based geographical detector (OPGD) model. The key findings are as follows: (1) From 2005 to 2020, the main ecosystem types were forest, grassland, and agriculture. Urban areas experienced significant changes, and conversions mainly occurred among urban, water, grassland and agricultural ecosystems. (2) Temporally, the GEP in the basin increased from 2005 to 2020, with regulation services dominating. At the county (district) scale, GEP exhibited a north-west-high and south-east-low pattern, showing spatial differences between per-unit-area GEP and county (district) GEP, while the spatial variations in per capita GEP and county (district) GEP were similar. (3) Differences in the spatial distribution of GEP were influenced by regional natural geographical and socioeconomic factors. Among these factors, gross domestic product, population density, and land-use degree density contributed significantly. Interactions among different driving forces noticeably impacted GEP spatial differentiation. These findings underscore the necessity of incorporating factors such as population density and the intensity of land-use development into ecosystem management decision-making processes in the upper reaches of the Chaobai River Basin. Future policies should be devised to regulate human activities, thereby ensuring the stability and enhancement of GEP. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Soil & Water Conservation (1009-2242) is the property of Institute of Soil & Water Conservation and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Green development is an inevitable choice for sustainable development under the constraints of environmental resources. This paper attempts to explore the connotation of urban land green utilization efficiency (LGUE) and reveal its spatial differentiation characteristics. This study adopts the super-SBM model to measure LGUE from 2009 to 2022 and analyzes the spatiotemporal variation rules. Then, the study reveals the spatial influencing factors of LGUE, drawing the following conclusions: (1) the average efficiency value of LGUE at the national level is still at a low level, but it is on an upward trend. There are significant differences in LGUE among the eastern, central, and western regions, with the highest LGUE in the eastern region and the lowest in the western region. (2) The spatial distribution of LGUE in various cities across the country is not entirely random but shows significant spatial autocorrelation characteristics. The improvement in LGUE in a region can improve the surrounding region's LGUE. (3) Economic development level promotes the improvement of local city LGUE, but its impact on LGUE of surrounding neighboring cities is not significant; local city industrial structure upgrading can improve LGUE in both local and neighboring cities; foreign investment in local cities can promote LGUE in both local and neighboring cities; the increase in population density will hinder LGUE in local cities but improve surrounding cities LGUE. The intervention degree of local city government will suppress the improvement of LGUE in both local and neighboring cities. [ABSTRACT FROM AUTHOR]

This study evaluates the new urbanization (NU) quality and the ecological resilience (ER) of 33 districts and counties in the Urban Agglomeration of Central Guizhou from 2010 to 2020. For this purpose, we used a modified coupled coordination degree (CCD) model, spatial autocorrelation analysis, and trend surface analysis to analyze the spatiotemporal evolutionary characteristics of the CCD of NU and ER. Meanwhile, we used a modified gravity model and social network analysis to investigate the spatial connection network (SCN) characteristics of the CCD of NU and ER. The results show that (1) the general NU quality has increased significantly in the Urban Agglomeration of Central Guizhou. There is, however, a downward trend in ER. (2) For the CCD of NU and ER in the Urban Agglomeration of Central Guizhou, there is coupling dissonance, with a double U-shaped arc, characterized by west > north > south > east > central. (3) The network density increases and then decreases. Network connectivity is 1, and network efficiency decreases and then increases. (4) During the study period, the SCN is characterized by significant core–edge characteristics; there are no "island nodes" in the SCN. [ABSTRACT FROM AUTHOR]

With the operation of the first route in Xi'an City, the matching relationship between the metro networks and the urban population is a root factor affecting the utilization of rail transit facilities. The mismatch between the metro networks and the urban population has led to an imbalance between the supply and demand for rail transport, resulting in wasted urban infrastructure. Based on this issue, the research objective is to focus on the spatiotemporal variations of the matching relationship. Firstly, the topological network model abstractly extracted metro spatial distribution features, and the spatial autocorrelation model was adopted to identify the evolution characteristics of the metro networks and urban population. Secondly, this paper adopted a time-lagged regression model to demonstrate the action relationship from 2011 to 2021. Then, the compositive coordination index was utilized to assess the variation of the global matching relationship. Finally, the paper explored spatial heterogeneity through the coupling coherence degree attached to grid cells. The research results indicate that the Moran's I value of metro elements decreased from 0.782 to 0.510 with the further complexity of topological networks, while the population was consistently high in spatial dependence with a Moran's I value of around 0.75 during the decade. Based on the regression coefficients and significance, this paper verified the hypothesis that the metro networks and urban population had a positive time-lagged feedback effect in urban development. From 2011 to 2021, the compositive coordination index symbolizing the global matching relationship increased from 0.29 to 0.90, but the coupling coherence degree shows significant spatial heterogeneity in different grid units. Differentiated spatial planning strategies were proposed for varied areas to efficiently utilize rail transit, which may provide a reference for other cities with the same reality problem. [ABSTRACT FROM AUTHOR]

The integrity and resilience of our environment are confronted with unprecedented challenges, stemming from the escalating pressures of urban expansion and the need for ecological preservation. This study proposes an Improved Remote Sensing Ecological Index (IRSEI), which employs humidity (WET), the Normalized Difference Vegetation Index (NDVI), Land Surface Temperature (LST), a standardized Building–Bare Soil Index (NDBSI), aerosol optical depth (AOD), and the comprehensive salinity index (CSI). The IRSEI model was utilized to assess the ecological quality of Hangzhou over the period from 2003 to 2023. Additionally, the random forest model was employed to analyze the factors driving ecological quality. Furthermore, the gradient effect in the horizontal direction away from the urban center was examined using the buffer zone method. Our analysis reveals the following: (1) approximately 95% of the alterations in ecological quality observed from 2003 to 2023 exhibited marginal improvements, declines, or were negligible; (2) the transformations in IRSEI during this period, including variations in surface temperature and transportation networks, exhibited strong correlations (0.85) with human activities. Moreover, the influence of AOD and the comprehensive salinity index on IRSEI demonstrated distinct spatial disparities; (3) the IRSEI remained generally stable up to 30 km outside the city center, indicating a trend of agglomeration in the center and significant areas in the surroundings. The IRSEI serves as a robust framework for bolstering the assessment of regional ecological health, facilitating ecological preservation and rejuvenation efforts, and fostering coordinated sustainable regional development. [ABSTRACT FROM AUTHOR]

Copyright of Natural Gas Industry is the property of Natural Gas Industry Journal Agency and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Coal plays a key role in the composition of energy production and consumption in China. The mineral is a crucial resource for human economic and social development. The surface subsidence caused by coal mining has attracted disturbance and damage to the surface ecological environments of mining areas. To quantitatively study vegetation carbon sequestration in coal mining areas, this article takes the Shendong mining area as its research object and analyzes the spatiotemporal distribution characteristics and influencing factors of vegetation net primary productivity (NPP). Based on meteorological data, remote sensing images, and land use data in the mining area, this research analyzed the vegetation NPP and its relationship with meteorological factors in the Shendong mining area from 2000 to 2023. The results show that (1) in the past 24 years, the range of NPP variation in the Shendong mining area has been 0–350 gC/m2. The overall NPP shows a fluctuating upward trend. The annual average change in NPP in the mining area is bounded by the two central dividing lines, with a lower value in the central part and a gradually increasing trend in the western and eastern parts. (2) The average vegetation NPP of the Shendong mining area over 24 years was 0–250 gC/m2; after 2011, the annual average NPP of vegetation was higher than this average level, which shows that the ecological environment of the mining area is gradually improving. Coal mining in the mining area has not caused a significant impact on the overall environment of the mining area. (3) There is a significant relationship between NPP and annual cumulative rainfall, average annual temperature, and average annual Normalized Difference Vegetation Index (NDVI). Overall, it is not significantly related to mining factors. The mining factors affect local areas and have a certain correlation. [ABSTRACT FROM AUTHOR]

Sustainable rural development is crucial for urban–rural integration and achieving shared prosperity. This study assesses rural development efficiency (RDE) at the county level in the Yangtze River Delta (YRD) region from 2012 to 2021 using the super-slacks-based measure model (SBM). By employing the Theil index and spatial Markov chains, this study explores the spatiotemporal evolution of RDE, categorizes rural development types, and proposes differentiated developmental pathways. The findings reveal (1) an initial upward trend in overall RDE in the YRD followed by stabilization, with regional disparities narrowing yet overall efficiency levels remaining relatively low; (2) a spatial distribution pattern of RDE characterized by high efficiency in the southeast and low efficiency in the northwest, forming a "core–periphery" structure, with pure technical efficiency identified as a significant bottleneck; (3) stability and "club convergence" in RDE, with geographic spatial patterns significantly influencing the transition process and a notable spatial spillover effect; (4) the classification of rural development types into six categories based on an "input–output–efficiency" perspective, each with specific developmental pathways. This study concludes that optimizing resource allocation efficiency and defining development pathways tailored to local conditions are essential for driving sustainable rural development in the YRD. [ABSTRACT FROM AUTHOR]

Faced with substantial climatic problems, industrial parks are crucial to attaining sustainable development objectives and China's carbon emission pledges. This study develops an output-oriented undesirable output Super-SBM model under non-incremental settings to evaluate the carbon emission efficiency of 169 national high-tech zones from 2008 to 2021. It utilizes the Dagum Gini coefficient and kernel density estimation approaches to analyze spatial variances and dynamic changes, as well as geographic detectors to assess the variables influencing the spatial development of carbon emission efficiency. This study uncovers a spatial distribution pattern of carbon emission efficiency within the eastern region of the national high-tech zone that is much superior to that in the western region. This tendency is mostly driven by inter-regional disparities. Carbon emission efficiency differences between various high-tech zones are progressively widening, displaying left-tail and polarization phenomena. Economic development gaps emerge as the main intrinsic factor contributing to spatial variations in carbon emission efficiency, with their interaction with land resource utilization being a key driving force. External factors, particularly differences in government interventions, dominate the spatiotemporal evolution of carbon emission efficiency, and their combined effect increases the evolution's explanatory power. These research findings offer a solid foundation for crafting region-specific carbon reduction policies in national high-tech zones and provide valuable insights for enhancing carbon emission efficiency in a coordinated manner. [ABSTRACT FROM AUTHOR]

Ethnic regions in China primarily focus on the development of agricultural and animal husbandry economies, which are relatively underdeveloped. Rural industry integration development (RIID) is considered the foundation and guarantee for ethnic regions to achieve high-quality modernization of agriculture. The purpose of this article is to measure the level of rural industrial integration in ethnic minority areas, analyze the spatial evolution and regional differences, and explore the actual situation of RIID in these regions. The aim is to provide a decision-making basis for local governments to effectively promote the development of rural industrial integration. Based on the improvement of the evaluation index system for rural industrial integration development, this paper takes the counties of the Inner Mongolia Autonomous Region as the research area. Utilizing panel data from the statistical yearbooks of 68 banners and counties in Inner Mongolia from 2011 to 2020, the panel entropy weight TOPSIS method is employed to assess the average level of rural industrial integration in the research area. The ArcGIS natural breakpoint method is employed to classify the level of RIID in county areas. Exploratory Spatial Data Analysis (ESDA) and GeoDa are utilized to analyze the spatial distribution characteristics of RIID. Finally, the Theil index is employed to analyze the regional differences in the level of RIID. The results show the following: (1) The overall level of RIID in ethnic regions is relatively low, with the contributions of the four dimensions in the evaluation index system as follows: integration path > integration foundation > integration sustainability > integration effect. The level of RIID in the study area is as follows: western region > eastern region > central region. (2) Spatially, there are positive correlations and significant spatial clustering in the level of RIID, with the spatial clustering effect of RIID weakening. (3) There are regional differences in the level of RIID, which are expanding. The inter-regional differences are decreasing, while the intra-regional differences are increasing. (4) The construction of agricultural processing facilities, financial investment, financial support, and talent policies are important influencing factors for the current stage of RIID in ethnic regions. Therefore, in the low-level development stage of RIID in ethnic regions, it is necessary to fully utilize the advantages of resource endowment, increase investment in rural infrastructure, and strengthen the guidance of talent flow into rural revitalization construction. [ABSTRACT FROM AUTHOR]

Accurately monitoring the morphology and spatiotemporal evolution characteristics of the entire process of slope erosion rill development is essential to circumvent the limitations inherent in traditional methods that rely on average flow velocity for hydrodynamic parameter calculations. This study employs an environmental chamber and a self-developed slope erosion test device to perform erosion tests on slopes with varying gradients and rainfall intensities. By integrating the structure-from-motion (SfM) method, fixed grid coordinate method, and continuous camera combined with the dye tracer technique, the morphological indexes and hydrodynamic parameters of the entire rill development process are precisely computed. The main conclusions are as follows: The entire process of slope rill development can be divided into three distinct stages. The initial stage is characterized by the appearance of tiny rills with mild erosion. The middle stage involves severe transverse spreading erosion and longitudinal undercutting, resulting in diverse rill morphologies. The final stage is marked by the stabilization of morphological characteristics. The peak slope soil loss is observed during the middle stage of rill development. The most effective parameters for characterizing slope soil loss from the beginning to the end are the Reynolds number and flow shear stress, the Froude number and flow shear stress, and the Froude number during different periods. Throughout the development of rills, the flow velocity initially decreases and then gradually increases until it stabilizes. The morphological indexes, including rill density, dissected degree, inclination, and complexity, generally show an increasing trend. However, in the middle stage, the rate of increase slows down, followed by a sharp rise at certain points. The optimal hydraulic parameters for evaluating rill density across different slope gradients, which were found to be the Darcy–Weisbach drag coefficient and real-time flow velocity, for assessing rill dissected degree, complexity, and inclination, were the Reynolds number and flow power. Under varying rainfall intensities, the most effective hydraulic and kinetic parameters for evaluating rill density, dissected degree, and inclination were flow shear stress and Reynolds number; for assessing rill complexity, the Reynolds number and flow power were used. The findings of this research enhance the accuracy of hydrodynamic parameter calculations in rill erosion tests, enable precise prediction of rill development trends on slopes, and offer innovative approaches for real-time dynamic monitoring of rill morphology and characteristics. These advancements are of significant importance for soil and water conservation and sustainability. [ABSTRACT FROM AUTHOR]

As an important indicator for assessing regional water resources, the study of the spatiotemporal evolution and driving factors of water resources carrying capacity (WRCC) is essential for achieving sustainable water resource utilization. This study focuses on Yulin City, a typical arid region located on the Loess Plateau in northwestern China. By constructing an evaluation index system for regional WRCC and combining an improved fuzzy comprehensive evaluation model with the TOPSIS evaluation model, a comprehensive WRCC evaluation model is established. Additionally, Geodetector is used to explore the main driving factors behind the evolution of regional WRCC. This multidimensional analytical framework aims to deeply analyze the dynamic evolution trends of WRCC and the driving mechanisms of different factors in its spatiotemporal changes. The results indicate that (1) from 2011 to 2020, the overall WRCC of Yulin City showed a trend of positive improvement, with Shenmu, Yuyang, and Fugu areas performing the best, and by 2020, more than half of the counties had achieved Grade 3 or above; (2) the spatial variability of WRCC in Yulin City was more significant than its temporal changes; and (3) in terms of driving mechanisms, the northern six counties gradually shifted from traditional economic-driven factors to ecological and environmental drivers, whereas the southern six counties remained constrained by economic factors. Overall, water resource factors remain the primary driving force for the socio-economic development and environmental sustainability of the entire Yulin City. The study provides valuable information for water resource allocation and differentiated management in arid regions. [ABSTRACT FROM AUTHOR]

Copyright of Environmental Science & Technology (10036504) is the property of Editorial Board of Environmental Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Rapid transit is important for the green development of China's tourism industry because it profoundly affects the optimal structural layout and rational allocation of elements that impact regional tourism. Based on provincial panel data from 2009 to 2020, the entropy weight method, tourism carbon emission measurement model, Super efficiency slacks-based measure model and threshold regression model were used to determine the impact of the rapid transit system on tourism eco-efficiency in China. The findings showed that rapid transit system has increased steadily, while tourism eco-efficiency has fluctuated significantly, and the relative development characteristics of rapid transit system and tourism eco-efficiency gradually changed from "lagging rapid transit system" to "lagging tourism eco-efficiency." In addition, the rapid transit system and the highway and civil aviation have a nonlinear relationship with tourism ecoefficiency, while the high-speed railway has not passed the threshold effect test, and at the regional level, the impacts of rapid transit system have heterogeneous characteristics. As the deepening construction of rapid transit system, its threshold effect on tourism eco-efficiency will change from positive "V" to positive "U" type, promoting the more efficient development of environmentally friendly tourism. [ABSTRACT FROM AUTHOR]

The spatiotemporal evolution of the flow structures and coolant coverage of double-row film cooling with upstream forward jets and downstream backward jets, having a significant impact on film-cooling performance, is studied using the simplified thermal lattice Boltzmann method (STLBM). Moreover, the effect of the inclination angle of downstream backward jets is considered. The high-performance simulations of film cooling have been conducted by using our verified in-house solver. Results show that special flow structures, such as a sand dune-shaped protrusion, appear in double-row film cooling with upstream forward jets and downstream backward jets, which is mainly because of the blockage effect resulting from the coolant jet with backward injection. The interaction among structures results in the generation of an anti-counterrotating vortex pair (anti-CVP). The anti-CVP with the downwash motion can result in the attachment of coolant to the bottom wall, which promotes the stability and lateral coverage of coolant film. The momentum and heat transport are strengthened as the backward jet is injected into the boundary layer of the mainstream. Although the downstream evolution of the backward jet is not very smooth, its core attaches closely to the bottom wall due to the downwash motion of anti-CVP. Moreover, there is an obvious backflow zone shown in the trailing edge of the downstream backward jet with a large inclination angle. The obvious backflow makes the coolant attach to the bottom wall well. Therefore, the film cooling effectiveness is improved as the inclination angle of the downstream backward jet varies from α d o w n = 135 ° to α d o w n = 155 ° , with a constant blowing ratio of B R = 0.5 . In addition, the fluctuation of the bottom wall's temperature is weak due to the stable coverage of the coolant layer under α d o w n = 155 ° . The film-cooling performance with an inclination angle of α d o w n = 155 ° is the best among all the cases studied in this work. This work provides essential insights into film cooling with backward coolant injection and contributes to obtaining a complete understanding of film cooling with backward coolant injection. [ABSTRACT FROM AUTHOR]

In the context of China′ s deepening rural revitalization strategy, significant changes have occurred in the rural living environment of the Beijing-Tianjin-Hebei urban agglomeration. Effectively identifying its spatiotemporal evolution characteristics and driving mechanisms are important for tailoring remediation strategies according to local conditions. This study focused on the BeijingTianjin - Hebei urban agglomeration rural areas and constructed a comprehensive evaluation index system for rural living environment quality based on the“Three Spatial Dimensions”system theory. Spatial analysis tools such as ArcGIS and geographic detector were utilized to characterize the spatiotemporal evolution features of rural living environment quality in 13 cities of the Beijing-Tianjin-Hebei urban agglomeration from 2011 to 2020 and investigate the evolution-driving mechanisms. The quality of rural living environment exhibited distinctive distribution characteristics in terms of social production space, natural ecological space, and resident living space quality, with a “south-high, north-low” “dispersed” and “staggered” pattern, respectively. Overall, the comprehensive quality of rural living environment showed a declining trend, with quality scores decreasing from 1.248 in 2011 to 0.947 in 2018, further rising to 1.164 in 2020. Spatial disparities became more pronounced, forming a distribution pattern of“south-high, north-low, and multi-core development”. This pattern includes core areas with high quality around Beijing, Tianjin, and Shijiazhuang, medium-quality areas centered around Hengshui, Langfang, Cangzhou, and Tangshan, and weaker areas primarily in Qinhuangdao, Chengde, and Zhangjiakou. The spatiotemporal evolution of rural living environment quality is mainly influenced by the collaborative impact of the production space system and the living space system. Rural industrial structure, industrial scale, and rural income levels are the primary factors affecting the spatiotemporal evolution of rural living environment. Enhancing the quality of rural living environment in the Beijing-Tianjin-Hebei urban agglomeration should focus on policy guidance, industrial development, and the synergy of rural culture and livelihoods. Tailored strategies for improving rural living environment quality should be developed based on local conditions. [ABSTRACT FROM AUTHOR]

Copyright of Arid Zone Research / Ganhanqu Yanjiu is the property of Arid Zone Research Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Air pollution, particularly fine particulate matter (PM2.5), poses a significant health risk, especially in high-density urban areas. Urban green space (UGS) can effectively mitigate this pollution. Despite their potential, strategies for effectively leveraging Land Use/Land Cover (LULC) optimization to combat PM2.5 remain largely unexplored. Ordinary least squares (OLS), geographically weighted regression (GWR) and multiscale geographically weighted regression (MGWR) were employed to investigate the spatial heterogeneity relationship between UGS conversion and PM2.5 fluctuations across various scales and evolutionary stages, developing a multiscale practical framework for LULC synergy in combating air pollution. The areas of UGSs to/from other LULCs, PM2.5 concentrations and corresponding variation zones exhibited significant spatial clustering. These UGS conversions explained more than 65% of the PM2.5 changes in the study area, peaking at 76.4% explanatory power in the fourth stage. Compared to global spatial analysis (OLS: 0–0.48), local spatial regression analysis significantly improved the R2 value (GWR: 0.32–0.75, MGWR: 0.48–0.90), but the fitting quality of local spatial regression analysis decreased with increasing scale, highlighting the importance of scale diagnosis. A 2 km scale was identified as optimal for assessing the spatial heterogeneity impact of UGS and other LULC conversions on PM2.5 changes. Conversion areas from water bodies and bare land to UGSs maintain stable local spatial properties at this scale (bandwidths: 44–99). Our research provides new insights into LULC management and planning, offering a coordinated approach to mitigating urban air pollution. Additionally, a practical framework was established for addressing spatially continuous variables such as PM2.5, revealing effective approaches for addressing urban environmental issues. [ABSTRACT FROM AUTHOR]

The in-depth discussion and analysis of the synergistic effect of new-type urbanization, greening and digitalization (NUGD) is important for the achievement of sustainable social, ecological and economic development. Therefore, in this study, an evaluation index system composed of these three subsystems was constructed for Chinese cities from 2011 to 2021. The comprehensive and collaborative development levels of each subsystem were measured by means including the entropy weight method and the coupling coordination model, respectively. Then, methods such as ESDA and the Dagum Gini coefficient were applied to investigate the spatiotemporal evolution and spatial differences in the triple synergy effect of the NUGD system in Chinese cities. Finally, the constraining factors of the triple synergy effect were revealed using the obstacle degree model. The findings demonstrated the following: (1) Overall, the NUGD subsystems and their comprehensive levels were increasing, with moderate overall development levels. (2) The synergistic development of the NUGD system exhibited an upward trend. Spatially, the synergistic development level showed distinct differentiation, being higher in the east and lower in the west. The multidimensional dynamic variation characteristics obtained through kernel density estimation revealed that the triple synergy level exhibits high stability. (3) The differences within the east and between the eastern and western areas were the largest, with the intensity of transvariation as the main source. (4) The five criterion layers, including social and spatial urbanization variables, were the key constraints that affected the triple synergy of the NUGD in Chinese cities, and the restrictive role of factors such as the proportion of urban construction land and the per capita postal business volume should not be ignored. This study provides a valuable reference and decision-making guidance to promote China's acceleration toward a new urbanization path supported by both digitalization and green transformation. [ABSTRACT FROM AUTHOR]

Studying the spatiotemporal evolution and driving forces behind construction land amidst the intricate ecological and geological setting on the eastern edge of the Qinghai–Tibet Plateau offers invaluable insights for local sustainable development in a landscape transition zone and ecologically fragile area. Using construction land data from four phases, spanning 1990 to 2020, in Mianning County, this study employs methodologies like the Landscape Expansion Index (LEI) and land use transfer matrix to delineate the spatiotemporal evolution characteristics of construction land. A comprehensive set of 12 influencing factors across five categories—geomorphology, geological activity, climate, river and vegetation environment, and social economy—were examined. The Geographically Weighted Regression (GWR) model was then employed to decipher the spatial distribution pattern of construction land in 1990 and 2020, shedding light on the driving mechanisms behind its changes over the three decades. The research reveals distinct patterns of construction land distribution and evolution in Mianning County, shaped by the ecological and geological landscape. Notably, the Anning River wide valley exhibits a concentrated and contiguous development mode, while the Yalong River deep valley showcases a decentralized development pattern, and the Dadu River basin manifests an aggregation development mode centered around high mountain lakes. Over the study period, all three river basins witnessed varying degrees of construction land expansion, transitioning from quantitative expansion to qualitative enhancement. Edge expansion predominantly characterizes the expansion mode, complemented by leapfrog and infilling modes, accompanied by conversions from cropland and forest land to construction land. An analysis of the spatial pattern and drivers of construction land change highlights human-induced factors dominating the Anning River Basin, contrasting with natural factors prevailing in the Yalong River Basin and the Dadu River Basin. Future efforts should prioritize climate change considerations and environmental capacity, aiming for an ecologically resilient spatial pattern of construction land. [ABSTRACT FROM AUTHOR]

Industrial land is essential for supply-side structural reforms, particularly in the Chengdu–Chongqing area, Western China's most densely populated and industrially robust region. This area, a pivotal hub linking Southwest China with South Asia and Southeast Asia, is critical for the national strategic layout and regional economic restructuring. Despite its substantial industrial foundation as an old industrial base, internal developmental stagnation has led to an irrational industrial land use structure. This paper analyzed land transaction data from the China Land Market Network (2010–2021) using methods such as kernel density estimation, the standard deviation ellipse method, and Global Moran's I index. The analysis focuses on the spatiotemporal evolution of industrial land marketization and its driving factors in 44 cities within the Chengdu–Chongqing economic circle. The findings aim to enhance the strategic implementation of national policies and regional economic optimization, suggesting intensified development efforts in key cities and promoting integrated growth in potential areas like Suining and Ziyang to foster a conducive environment for high-quality regional development. [ABSTRACT FROM AUTHOR]

Introduction: With the rapid advancement of industrialization and urbanization in the Yellow River Basin, the number of resource-based cities is constantly increasing, leading to an imbalance in land use structure and the gradual worsening of adverse effects such as damage to the ecological environment. Hence, improving the efficiency of green land use in resource-based cities has extremely crucial ecological and practical meaning for sustainable development. Methods: This study comprehensively considers interdisciplinary theories such as ecology and management, and combines the actual situation of resource-based cities in the Yellow River Basin to construct a new type of urban field green utilization efficiency assessment index system. To promote the coordinated development of different dimensions, the corresponding spatiotemporal evolution process and related influencing factors were also analyzed. Results and discussion: The research results indicate that the overall spatial evolution of the Yellow River Basin has active correlation. During the period from 2006 to 2022, the number of high value agglomeration cities in upstream resource-based cities increased by nearly 25%; Nearly 3% of resourcecities exhibit low-value heterogeneity, while the number of resource cities with low value agglomeration has decreased to 0. In addition, population density and scientific education expenditure level are key factors affecting the ratio of green land use in resource-based cities, while the impact of economic indicators is gradually decreasing. In summary, the assessment indicator system for urban land green utilization ratio proposed in the study is more comprehensive, and the spatial distribution results of influencing factors can provide a solid data foundation for decision-makers. [ABSTRACT FROM AUTHOR]

Optimizing production–living–ecological space (PLES) can benefit territorial space planning and sustainable development in China. Thus, spatiotemporal evolution characteristics and influence factor analyses are vital. Laiwu, China, was selected as the study area due to its complex terrain and development history. A multitemporal land-use and land-cover classification extracted from Landsat remote-sensing images for 2001–2018 and the self-organizing map method were combined to identify the area's multitemporal PLES. The PLES evolution trajectories were extracted based on the multitemporal PLES. The main factors influencing the PLES spatiotemporal evolution differences were revealed using the random-forest-based factor importance evaluation method. The results showed that changes in the PLES trajectories occupied ∼ 18% of the study area. The ecological space recovery type was mainly observed in previously stable ecological space areas. Changes in the production space expansion (PSE) and living space expansion were mainly agglomerated in the fringe areas of previously stable production–ecological and living space lands. Distance from early built-up areas was the main factor influencing PLES expansion. Ecological space was mainly distributed far away from built-up areas, and living and production spaces were mainly distributed near the built-up areas. Additionally, the slope of the terrain affected the spatial distribution of PLES expansion to a certain extent, and the gross domestic product clearly affected the distribution of PSE. [ABSTRACT FROM AUTHOR]

[Objective] This study aims to quantify and analyze the temporal and temporal changes of ecosystem service value in the urban agglomeration around Poyang Lake, and to explore the trade-off and synergy between ecosystem services, which provides decision-making reference for regional ecological environmental protection and restoration. [Methods] Based on the land use data of the Poyang Lake urban agglomeration in the years 2000, 2010, and 2020, this study employed methods such as the Equivalent Service Value (ESV) factor approach, ecological contribution rate, and the ecosystem service balance and synergy model to investigate the spatiotemporal variations in the ecosystem service values (ESV) and the balanced and synergistic relationships among ecosystem services in the Poyang Lake urban agglomeration.. [Results] (1) In 2000, 2010 and 2020, the ecosystem service value of the urban agglomeration around Poyang Lake was 416.350 billion yuan, 421.953 billion yuan and 420.293 billion yuan, respectively. During the study period, the ESV of forestland was the largest, and the ESV of hydrological regulation was the largest among the single service functions. (2) The spatial distribution pattern of ESV was relatively stable, with the medium and high value grids distribution in large lakes, reservoirs and main roads of water systems, and the low value grids distribution in urban built-up areas and rural agglomeration areas with high cultivated land development. The areas with an increase in ESV were mainly in the periphery of Poyang Lake, and the areas with a decrease in ESV were in the urban built-up areas of Nanchang City, the northeast of Jiujiang City, Yingtan City and other districts and counties. (3) Water area contributed the most to ESV change, which was the main factor affecting the increase and decrease of ESV in the urban agglomeration around Poyang Lake. (4) The synergistic relationship was the dominant relationship between ecosystem services during the study period, and the trade-off relationship mainly existed between water supply, environmental purification, hydrological regulation and other ecosystem service functions. [Conclusion] Restoring and protecting waters, forests and grasslands, and strictly controlling the expansion of construction land are the effective measures to maintain the benign growth of ESV and ecological security of the urban agglomeration around Poyang Lake. [ABSTRACT FROM AUTHOR]

[Objective] This study aims to investigate the spatiotemporal evolution characteristics of rural settlements in Jiangxi Province, and to analyze the influencing factors. The findings can serve as reference and decision-making basis for promoting the national rural revitalization strategy, optimizing territorial spatial planning, and enhancing rural governance. [Methods] The spatiotemporal evolution of rural settlements in Jiangxi Province from 2000 to 2020 was examined by using landscape pattern indices, kernel density analysis, and gravity shift model. The buffer analysis and geographic detection were employed to explore the influencing factors. [Results] (1) The number of rural settlements in Jiangxi Province decreased, but their scale expanded over rime. The variation between different settlement scales initially increased and then decreased, while the irregularity of settlement patterns remained generally low. (2) While the overall change in rural settlement distribution in Jiangxi Province was modest, significant spatial differences were observed. The pattern exhibited a spatial distribution of dense pattern in the middle and sparse on all sides, dense pattern in the north and sparse in the south. (3) The center of gravity of rural settlements in Jiangxi Province remained relatively stable over the past two decades, consistently located in the southwest of Fengcheng City. (4) Rural settlements in Jiangxi Province were mainly found in areas with elevations below 200 m and slopes between 5° and 15°. They were notably influenced by rivers, county and township roads, while railways, highways, national roads and provincial roads had minimal impact. Among socio-economic factors, the output value of grain crops, rural residents′ the consumption expenditure, and cultivated land area had the most significant influence. [Conclusion] The spatiotemporal evolution of rural settlements in Jiangxi Province remained stable during 2000—2020. The distribution of rural settlements was influenced by location, natural and socio-economic factors. [ABSTRACT FROM AUTHOR]

[Objective]The aims of this study are to explore the coupling and coordination relationship and influencing factors of regional production-living-ecological spaces(PLES)function, and to guide the optimization of regional land spatial pattern and realize high-quality sustainable development.[Methods]Kunming was taken as an example. Based on the construction of the evaluation index system of the spatial function of PLE, Entropy weight method, linear weighting method, ternary diagram and coupling coordination degree model were integrated to quantitatively measure the spatial and temporal characteristics of the coupling and coordination of the spatial function of PLE in Kunming from 2000 to 2020, and geographical detectors were used to explore the dominant factors affecting the development of the spatial function of PLE in Kunming.[Results](1)From 2000 to 2020, the PL space function of Kunming City showed an overall upward trend, and the ecological space function showed a downward trend. Driven by policy measures and project construction site selection, the urban function positioning changed. The PLES function mainly experienced the EL and PLE advantage equilibrium area, and it was found that 2010 was an important turning point for entering the balanced development of PLE.(2)In the past 20 years, the overall fluctuation of the functional coupling coordination degree of PLE in Kunming City had been small, and it had experienced the basic coordination and moderate coordination stages, showing a pattern of high level around and low level in the middle in space.(3)The main factors affecting the coupling and coordination of PLES functions in Kunming were the per capita sown area and forestland area, and the interaction of factors increased the explanatory power of the development of PLES functions.[Conclusion]Among them, the habitat quality is less stable and volatile in the development of PLES functions. [ABSTRACT FROM AUTHOR]

[Objective] The present paper aimed to analyze the spatial-temporal agglomeration changes and driving factors of three major oil crops in China from 2000 to 2020, namely soybean, peanut and rape, so as to provide reference for optimizing the production layout of edible oil crops. [Method] The spatiotemporal agglomeration evolution characteristics and driving factors of soybean, peanut and rape production were analyzed by using the gravity shift model, exploratory spatial data analysis, spatiotemporal geographical weighted regression model and other methods. [Result] (i) The yield of soybean was the highest, followed by peanut, and the yield of rape was the lowest. The yield of soybeans showed a significant fluctuation increase, while the yield of rapeseed and peanut showed a slight fluctuation increase. Soybean production was mainly distributed in Heilongjiang, Inner Mongolia, Henan and Anhui. Peanut production was mainly distributed in Shandong, Henan and Guangdong. Rape production was mainly distributed in Sichuan, Hubei and Hunan. (ii) From 2000 to 2020, the yield agglomeration degree of three oil crops showed a weakening trend, and the high-high accumulation areas of soybean yield were in Heilongjiang and Jilin, and the low-low accumulation area was in Xinjiang; The high-high accumulation areas of peanut yield were in Shandong, Henan and Anhui, and the low-low accumulation area was in Xinjiang; The high-high accumulation areas of rape yield were in Hubei, Anhui and Jiangxi, and the low-low accumulation area was in Inner Mongolia. The production center of soybean moved to the northwest from Tanghai county in Hebei province to Ningcheng county in Inner Mongolia. The production center of peanut was located in Henan province and was moving to- wards the northwest of Henan province; The production center of rapeseed shifted to the southwest from Nanzhang county in Hubei province to Fengjie county in Chongqing. (iii) The driving factors of different oil production had different effects in different provinces. Soybean pro- duction was mainly affected by population density, fertilizer application and GDP growth rate; Peanut production was mainly affected by chemical fertilizer application, total mechanical power and irrigation area; Rapeseed production was mainly affected by population density, urbanization rate and road density. [Conclusion] The production of three main oil crops has obvious spatial agglomeration characteristics, and the influencing factors are different, which are mainly affected by social and economic factors such as chemical fertilizer application. [ABSTRACT FROM AUTHOR]

Vegetation areas are vital for enhancing the sustainability of urban ecosystems. However, ongoing urbanization gradually reduces these areas in cities, leading to a decline in ecological benefits. This study integrates fractional vegetation cover and land surface temperature in understanding the changes in vegetated areas and ecological benefits from 1990 to 2020 in eight central districts of Nanjing using the CITYgreen model and geographically weighted regression. The findings show that human intervention resulted in a reduction of urban vegetated areas by 22.84%, while non-vegetated areas have increased by 1.24 times. The total value of ecological benefits was reduced by approximately 57.41%. The landscape pattern experienced gradual fragmentation, evidenced by a decrease of approximately 62% in the largest patch index (LPI). Both the mean shape index (SHAPE-MN) and landscape shape index (LSI) showed significant increases, indicating a rise in the complexity of landscape patches due to human intervention. [ABSTRACT FROM AUTHOR]