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The Chengdu Plain serves as the central hub for economic development in Sichuan Province. The study of its surface deformation plays a pivotal role in disaster prevention and ensuring the safety of lives and property. Based on SBAS-Interferometric Synthetic Aperture Radar technology, this paper derived the land surface deformation in the Chengdu Plain from January 2020 to October 2022, and analyzed it in relation to urban development and other natural environmental factors. Results are as follows: (1) The overall surface deformation in the study area remains stable, with a noticeable trend of westward uplift and eastward decline. Significant uplift is identified in Dujiangyan and Pengzhou, located near the Longmen Mountain, with a maximum uplift rate of +61 mm/year. Conversely, subsidence is evident from Qingbaijiang District in Chengdu to Deyang, with subsidence rates reaching a maximum of −87.8 mm/year. In the areas of Dayi and Qionglai, subsidence is relatively minor. The surface subsidence phenomenon in the study area is primarily associated with urban development. (2) The mean grey correlation coefficient between the time-series cumulative surface deformation and precipitation is 0.71, which suggests a strong relationship between the surface deformation and precipitation in the Chengdu Plain. However, a time delay is observed between the changes in surface deformation and precipitation. (3) The Longmen Mountain tectonic belt extrudes and lifts the premountain plain, playing a crucial role in shaping its topography. Additionally, the concealed fracture zone of Xinjin-Chengdu-Deyang may have contributed to surface subsidence. (4) After eliminating the effect of human factors, the cultivated land and grass land cover types exhibit a subsided state, whilst the artificial surface deformation is relatively stable, and the forest land exhibits an uplifted state. Surface deformation on different land cover types is correlated with water permeability, but it is also influenced by other factors. [ABSTRACT FROM AUTHOR]

The paper contributes to the literature on rural gentrification by incorporating empirical evidence from amenity-poor rural areas in the developing world. While current literature on rural gentrification has largely focused on the gentrification process in amenity-rich rural areas, the present study examines rural gentrification process in a historically polluted county in Chengdu, Sichuan Province, China. The gentrification process features a holistic transformation of farmland into an artificial landscape, thereby segregating gentrifiers from both polluted rural space and unwelcoming urban space. The paper attributes the rise of holistic gentrification to state-initiated farmland concentration, and to the gentrifier developers' practices of redefining rurality as immersive resort experiences. The paper concludes that the holistic gentrification was conducive to job losses in both the recreation and agricultural sectors, consequently reducing peasant households to a state of passivity and dependency, while collective actions against gentrifier developers were ineffective owing to highly skewed power dynamics. • Holistic gentrification transforms large-scale farmland into scenic rural resorts in amenity-poor rural areas in China. • Holistic gentrification is caused by national peasant relocation programs. • Gentrifier developers redefine rurality as immersive resort experience. • Holistic gentrification is conducive to local job losses in recreation and agricultural sectors. [ABSTRACT FROM AUTHOR]

The Xigeda formation, widely distributed in southwestern China, is a special semi-diagenetic rock with horizontal bedding，which is mudding in water. In order to study the failure law, catastrophe characteristics and catastrophe mechanism of the interbed type to the surrounding rock and structure of Xigeda formation tunnel, this paper, by means of field investigation, indoor test, numerical simulation, field monitoring and theoretical research, relying on more than ten Xigeda formation tunnels in the Chengdu-Kunming double track railway, analyzes the apparent failure characteristics and catastrophe mechanism of the surrounding rock of Xigeda formation tunnels with different interbed types. The results show that: the catastrophe characteristics of Xigeda formation tunnel have certain water content sensitive area and influence area division of interbed type. The water content of Xigeda formation is 25% - 30% of the catastrophic critical region of Xigeda formation tunnel. In this critical region, the vault of the overlying Xigeda formation tunnel is prone to large deformation, the invert of the underlying Xigeda formation tunnel is prone to large uplift deformation, and the side wall and tunnel face of interlayer Xigeda formation tunnel are prone to large extrusion deformation; when the water content of Xigeda formation is 30%, it becomes a weak layer, and under the effect of interbed, the rock and soil of Xigeda formation are prone to large deformation, resulting in catastrophes by extruding the tunnel structure; based on the analysis of chemical effect, physical effect and mechanical effect, the structural components of interbed rock chemically react with water, leading to weakening of the strength and causing catastrophic effects. The catastrophic effect is similar to that of simply supported beam in the strong and weak regions of the interbed, while the weakening effect of the interlayer structural plane leads to the opening of the interlayer fracture plane of the tunnel surrounding rock and the large interlayer dislocation displacement, which forces the shear failure of the supporting structure. The research results of this paper can provide theoretical guidance for the Sichuan-Tibet railway to be constructed. • The research object is Xigeda stratum which is sensitive to water. • Reveal the disaster modes of Xigeda stratum tunnels with different interbed types. • Investigate the catastrophic mechanism of Xigeda stratum tunnel under interbed effect. • Obtain the catastrophic critical water content of Xigeda stratum tunnel. • Provide theoretical basis for Xigeda stratum tunnel construction. [ABSTRACT FROM AUTHOR]

• The spatial competitions contribute to the evolution of rural residential land (RRL). • RRL in study area is characterized with "dense in the west and sparse in the east". • Evolution of RRL is impacted by macro factors and micro housing selection. • Spatial distribution pattern of RRL will remain nearly unchanged in the long run. Spatial systematic competition definitely contributes to rural residential evolution. Rural residential land of mountainous economic circle is generally hard to govern due to the disturbances from natural factors and economic activities. This study established a framework and adopted Kernel Density Estimation (KDE), Exploratory Spatial Data Analysis (ESDA), Geographical detector (Geo-detector) and Patch-generating Land Use Simulation (PLUS) to examine the evolution characteristics, drivers and trends of rural residential land of Chengdu-Chongqing Economic Circle(CCEC). Our research uncovered that: 1) The competitions between rural living space (RLS), rural production space (RPS) and rural ecological space(RES) substantially contribute to the evolution of rural residential land according to the conceptual framework, and the evolution in mountainous economic zone is greatly impacted by the close coupling interaction of macro driving factors and micro farmers' housing selection. 2)The characteristics of rural residential evolution of Chengdu-Chongqing area presents "dense in the west and sparse in the east", and the majority of which are concentrated in Sichuan Basin and Chengdu plain area. 3) Although the size of rural residential land in Chengdu-Chongqing area presents a fluctuant downward trend according to the simulation results, the spatial distribution pattern will remain nearly unchanged in the long run. 4) Rural residential evolution reflects the interactional process of muti-factors, as well as the matching result between man-land relationship and regional development goals under the land use policies. Overall, The theoretical and empirical research form the perspective of spatial competition in this paper provides a new idea for future studies on the evolution of rural residential land. [ABSTRACT FROM AUTHOR]

• Villagers exhibit endowment effects of varying intensity through withdrawal from rural homesteads (WRH). • As the degree of villagers' non-agricultural activities increase the endowment effect is more intense. • Emotional attachment to rural homesteads, property right status, and substitutability of rural homesteads affect villagers' endowment effects. • The endowment effect accompanying WRH should become an important factor for WRH policymakers. The withdrawal from rural homesteads (WRH) refers to a mechanism to encourage villagers to withdraw from their vacant homesteads or give up their occupied homesteads (including the houses built on them) voluntarily and move into high-rise buildings with compensation. WRH aims to address inefficient utilization of rural land in China. However, the endowment effect, a behavioral tendency for villagers to value rural homesteads more highly when they own them relative to when they do not, may affect the process of implementing WRH policy. Based on survey data from 878 villagers in Chengdu, Sichuan Province, this paper estimates endowment effects for different types of villagers whose rights to their rural homesteads could be withdrawn. It then makes an empirical analysis on the differences and influencing factors of villagers' endowment effects related to WRH via a binary logistic model querying emotional attachment , property right status , and substitutability of rural homesteads. The results show 70.62 % of sampled villagers exhibit an intensive endowment effect after WRH. Meanwhile, as non-agricultural economic activities increase, villagers' endowment effects intensify. In terms of influencing factors, emotional attachment and cognition of inheritance rights strengthen the degree of pain experienced by villagers when they withdraw from their rural homesteads, thereby enhancing endowment effects. Property certificates and cognition of disposal rights negatively affect villagers' endowment effects. From the perspective of villagers' differentiation, cognition of mortgage rights intensifies the feelings of security within rural homesteads for full-time agricultural households, thereby intensifying endowment effects. Substitutability of villagers' livelihood positively affects endowment effects in full-time agricultural households and negatively affects endowment effects in non-agricultural households. This paper concludes by discussing the land use policy implications of these findings. [ABSTRACT FROM AUTHOR]

Chengdu, located at the western edge of the Sichuan Basin, is the provincial capital of Sichuan Province. The fertile and well-watered basin has given the city a long and splendid history, which has left significant and lasting imprints on its urban form, landscape and cultural life. In the planned economy period, Chengdu serviced as the economic, cultural, logistical and technological center for southwest China, and built a competitive and broad industrial base which now helps the city maintain its leading position in the region. In 2007, Chengdu was assigned as one of two pioneer cities in coordinating urban–rural development. This paper introduces the urban development of Chengdu as a historical city, summarizes the city’s economic growth, urban spatial transformation and infrastructure construction as a major city in western China, and discusses its recent efforts in coordinating urban–rural development as a pioneering city in China. [ABSTRACT FROM AUTHOR]

The Sichuan Basin (SCB) has suffered from serious ozone (O 3) pollution in recent years, especially in summer. However, the formation and evolution mechanisms of O 3 pollution in the SCB remain poorly understood. In this paper, we comprehensively investigated the causes of elevated ozone concentrations in Chengdu in July 2017 with a combination of field measurements and the WRF (Weather Research and Forecasting)-CMAQ (Community Multi-scale Air Quality) model simulations. The ozone formation characteristics of continuous O 3 episodes and non-O 3 episodes were compared. Higher temperature (T), stronger solar radiation (SR), lower relative humidity (RH) and weaker winds were conducive to O 3 formation during ozone episodes. The O 3 concentration during O 3 episodes (202.6 μg m−3) was significantly higher than that during non-O 3 episodes (122.7 μg m−3), attributable to the higher volatile organic compounds (VOCs) concentration (34.0 ppbv compared with 27.5 ppbv) despite comparable NO x concentrations during O 3 episodes. The results of positive matrix factorization (PMF) for ambient VOCs showed that gasoline vehicle exhaust and solvent usage were the dominant sources during the month. However, the increasing source attributions from the petrochemical industry and biogenic emissions were responsible for the elevated VOCs concentrations during O 3 episodes. The relative contributions of local emission and regional transport to ozone were quantified during two O 3 episodes by conducting numerical sensitivity experiments. In the first episode, namely, the "O 3 -regionally transported" pattern, high ozone concentration in Chengdu was primarily due to the regional transport of ozone and ozone precursors through vertical mixing and horizontal advection from upwind areas (central and eastern SCB) when easterly or southeasterly winds prevailed over the SCB. In contrast, in the second episode, namely, the "O 3 -locally dominated" pattern, high local emissions under favorable meteorological conditions are the major reason for elevated ozone concentration. The process analysis results from the CMAQ model suggested that the vertical transport of O 3 that formed at the upper levels from intense gas-phase chemistry reactions was a dominant contributor to diurnal O 3 enhancement in O 3 episodes by 45 μg m−3, while horizontal transport contributed more than 80% of the nocturnal O 3 concentration. This study provides a better understanding of ozone photochemical formation and regional transport mechanisms in the SCB under complex terrain conditions, and contributes to ozone pollution prevention in other basins around the world. • Two high O 3 episode in Chengdu was simulated using the WRF-CMAQ modeling system. • Ozone and precursors from upwind-polluted areas are crucial to high ozone episodes in Chengdu. • Vertical mixing plays an important positive role to surface elevated ozone in Chengdu. [ABSTRACT FROM AUTHOR]

With the development of social economy, a series of problems such as an imbalance of supply and demand, unreasonable resource allocation and low operation efficiency appear in the urban taxi market. Based on the GPS trajectory data of taxis, this paper calculates and analyzes the operation efficiency of taxis in terms of time and space dimensions in Chengdu, Sichuan Province by using the capacity utilization rate. The results show that, firstly, the weekly variation trend of taxi capacity utilization rate is obviously periodic and its daily variation trend is unbalanced, which is reflected in the morning peak, afternoon peak, evening peak and night peak. The daily variation trend of taxi capacity utilization rate is significantly different between workdays and weekends, and the capacity utilization rate on weekends is much lower. Secondly, there is a spatial imbalance in the distribution of taxi capacity utilization rate. The capacity utilization rate of the main urban district is relatively high, and that of the other urban districts negatively correlates with the economic level and population density. The supply and demand of taxis are balanced within the various functional zones but unbalanced between different functional zones. It is suggested that the relevant departments shall reasonably allocate taxi resources according to the imbalance of taxi capacity utilization rate in time and space to improve the overall operation efficiency, and integrate market mechanism with government regulations to promote the sustainable development of urban taxis. • From the time dimension, the weekly variation trend of taxi CUR shows obvious periodic features. • For the four CUR peaks, the CUR in morning and evening is much lower than that in noon and night. • The imbalanced taxi CUR in functional zones is affected by the distribution of POI and order demand. • A negative correlation between the order counts and CUR implies unreasonable resource allocation. [ABSTRACT FROM AUTHOR]