109.Understanding the determinants of where and what kind of home accommodation to build
Ecological Indicators,October，2023
Qian Yun, Zhu Huizhen, Wu Jiansheng
Abstract：As homestays have developed rapidly, it is necessary to understand the factors affecting their density and type distribution at the micro scale. Based on the Internet data of home accommodation, the spatial distribution characteristics of homestays in Shenzhen are studied by the nearest neighbour analysis, and type distribution characteristics are analysed by NVivo. The impacts of factors are discussed through geographical detectors. We conclude that Shenzhen's homestays are multi-centre agglomeration and development in space with the flat floor as the main house structure and the modern style as the main decoration style. The spatial distribution is mainly affected by social and economic factors such as the density of bus stations and subways. The density and diversity of the homestays is high with the nearest and farthest distance to the railway station and the popular tourist destination beach while low with the mediate distance, featured with dumbbell shape.
Ecological Indicators,September 2023
Wu Jiansheng;Fan Xuening; Li, Kaiyang; Wu, Yuwei
Abstract:Exploring the spatial flow pattern of ecosystem services and clarifying the transmission path between the supply area and the demand area will help to formulate more scientific and reasonable ecological protection policies. This paper takes the rapid urbanization area representing the Pearl River Delta urban agglomeration as an example. Using Invest model to quantitative the assessment of the supply and demand of carbon sequestration services and water ecosystem services from 2000 to 2020, a spatial flow model of ecosystem services is constructed to clarify the spatial flow of regional ecosystem services pattern. In addition, the Geo-detector model is used to explore the driving factors of the supply and demand relationship of ecosystem services, and the spatiotemporal geographic weighted regression model is further used to analyze the temporal and spatial differentiation of the impact degree. Finally, based on the Bayesian belief network, the optimal state factor configuration is selected to optimize the spatial pattern, and the corresponding optimization strategy is given. The main conclusions are as follows: (1) The supply of carbon sequestration services in the Pearl River Delta decreased gradually during 2000-2020, while the demand increased gradually. The supply of water ecosystem services increased first and then decreased, while the demand showed a downward trend. (2) In terms of spatial heterogeneity of supply and demand matching, the main driving factors of carbon sequestration services included night light brightness value, temperature and vegetation index; The main driving factors of water ecosystem services include night light brightness value, land use type and vegetation index. (3) In terms of optimal areas for supply and demand matching, carbon sequestration services were mainly distributed in Zhaoqing, Huizhou and Jiangmen; The optimal matching areas of water ecosystem service supply and demand were mainly distributed in Zhaoqing, Guangzhou, Huizhou and other cities.
Resources, Conservation and Recycling, February 2023
Zhang Danni, Zhao Yuhao, Wu Jiansheng
Abstract:Carbon sink in terrestrial ecosystems is critical for achieving carbon neutrality; however, its environmental sensitivity and potential remain uncertain. A comprehensive framework was established to assess the carbon balance attribution and carbon storage potential. The net ecosystem productivity was integrated with the maximum entropy model and the patch-generating land use simulation model for analysis. In 2017, ecosystems in China produce 0.44 Pg C and store 1.66 Pg C, with sources in the west and sinks in the east. The Sichuan Basin, North China Plain, Loess Plateau, Inner Mongolia Plateau and Northeast China Plain experience the historical carbon source-to-sink conversion. The potential for the sink-to-source conversion increases from central to eastern and western China and precipitation contributes 52.3%. A high possibility of potential sink-to-source conversion concentrates in Eastern Qinghai-Tibet Plateau, middle-lower Yangtze River plain and eastern coastal areas of China. The carbon sink in terrestrial ecosystems of China is expected to be 23.58 Pg C in 2030, with the central subtropical broad-leaved evergreen zone accounting for 21.33%. The risk of the decline in carbon stocks is 0.45-0.54 Pg C. The results serve as scientific references for achieving carbon neutrality and sustainable development goals.
Applied Geography, February 2023
Zhao Yanni, Wang Man, Lan Tianhan, Xu Zihan, Wu Jiansheng, Liu Qianyuan, Peng Jian
Abstract:Ecosystem services (ESs) trade-offs are directly influenced by land use change which resulted from urbanization and ecological restoration globally or locally. However, the impacts of land use policies on ESs and their trade-offs are always interacted, needing further distinguishment. In this study we simulated grain production and water purification of the Dongting Lake Basin under different land use scenarios in 2035, and explored the impact of land use policies on ESs and their trade-offs. The results showed that returning farmland to forest land was the main factor, which would lead to 3.19% decrease in grain production and 8.13% increase in water purification. Returning farmland to waterbody would also result in a reduction of grain production (-0.85%) slightly more than the improvement of water purification (0.37%). However, the impact of urbanization on ESs would be less but spatially heterogeneous. It is worth noting that returning farmland to forest land would increase the trade-off potential and intensity, while urbanization and returning farmland to waterbody could weaken both trade-off indices. This study provides a scenario approach to distinguishing land use policies' impact on ecosystem services trade-offs.
Urban Climate，January 2023
Zhang Xiwen, Mao Feng, Gong Zhaoya, Hannah David M., Cai Yunnan, Wu Jiansheng
Abstract:Resilience has been widely used as a concept to analyse, understand, and improve cities' coping capacities to disasters. However, it is still a challenge to operationalise and quantify resilience. This study proposes a framework for assessing resilience to disasters based on the relationship between disaster intensity and damage rate. We use intense (short-term heavy) rainfall-induced urban flooding in Shenzhen city, one of the largest cities in China, as an example to explore the main features and transferability of the proposed resilience assessment framework. In addition, we demonstrate the usability of the proposed framework by using it to assess and compare the effectiveness of two resilience-building strategies: (1) permeable pavement transformation and (2) land vulnerability reduction. This research makes an innovative contribution through its effective disaster-damage-based approach for quantitatively evaluating urban resilience to disasters, which can support building resilience and mitigating the impact of climate change.
Science of The Total Environment, December 2022
Tengyun Yi, Han Wang, Chang Liu, Xuechen Li, Jiansheng Wu
Abstract: Rapid urbanization has changed the urban spatial form, which directly leads to the emergence of urban informal settlements, and the impact on ecological environment is manifested as the obvious deterioration of urban thermal environment. The thermal environment of informal settlements, which are called urban villages in China, is seriously deteriorated. In the process of urban renewal, we should pay attention to the thermal environment effect of urban villages and promote the sustainable development of cities. However, at present there are few studies on the differences of thermal comfort among urban settlements. Taking Shenzhen as an example city, this paper distinguished several scopes such as urban villages, formal settlements and non-urban areas, then analyzed the pattern characteristics of urban thermal comfort by using the Modified Temperature and Humidity Index (MTHI), and finally explored the spatial relationship between thermal comfort and various environmental factors through spatial regression models. The results show that (1) thermal comfort has significant spatial autocorrelation and the thermal environment centers are clustered in built-up areas of Shenzhen city. The overall MTHI of urban villages is relatively the highest, and the dominant thermal comfort level in summer is sultry and hot. (2) According to the Spatial Error Model, the green space coverage represented by NDVI has the strongest mitigation effect on urban thermal comfort, and the building density has an obvious aggravating effect on the muggy environment. Both of them have more obvious effects on the thermal comfort of informal settlements. (3) The current thermal environment of urban settlements cannot be ignored, especially in urban villages. In the process of urban renewal, heat dissipation should be considered emphatically. Increasing urban green area and decreasing building density will help to improve urban thermal environment. The study can provide suggestions for urban renewal from the perspective of improving thermal environment.
Science of The Total Environment, August 2022
Zhenyu Wang, Keyu Luo, Yuhao Zhao, Alex M. Lechner, Jiansheng Wu, Qingliang Zhu, Wei Sha, Yanglin Wang
Abstract: Long-term intensive open-pit mining can have huge impacts on ecosystems and the services they provide, affecting the integrity of ecosystem structures, functions and process and thus the “ecological security” of a whole mining region. The indirect and direct impacts of mining are spatially and temporally complex and therefore ecological security patterns need to be considered. However, to date there has been little research focusing on ecological security patterns in mining regions. This study aims to model and map ecological security and restoration priorities in an intensive open-cut coal mining region accounting for spatio-temporal changes of multiple ecosystem services. Four ecosystem services including habitat quality, carbon sequestration, water yield, and sediment retention were assessed and mapped in 1990, 2000, 2010, and 2020. Next ecological security patterns and restoration priorities were modelled and characterized using the Self-Organizing Feature Map to identify ecological sources, and circuit theory in Linkage Mapper to characterize connectivity and flows. The results showed that habitat quality, carbon sequestration, and water yield services were most affected by vegetation cover changes due to mining exploitation, while sediment retention was influenced by multiple natural factors, especially topography. Ecological sources, corridors, pinch-points and barriers showed various changing trends due to mined and built-up land expansion over time. Ecological source area declined from 1355.08km2 in 2000 to 584.92 km2 in 2020, while the number of corridors increased from 17 in 2000 to 25 in 2010 and then decreased to 21 in 2020. Although restoration has been conducted on some mine sites, regional-scale restoration needs greater consideration. This study provides decision-makers and stakeholders with a method for assessing regional-scale ecological security and restoration in a holistic and systematic way moving beyond a single mine, which is critical for balancing ecological security protection with minerals production in intensive mining regions.
Ecological Indicators, June 2022
Jian Peng, Huiling Lü, Ruilin Qiao, Shuying Yu, Zihan Xu, Jiansheng Wu,
Abstract: The Grain-for-Green Program (GFGP) in China, one of the largest payment fot ecosystem services (PES) programs, has been regarded as an effective approach to achieving sustainable development. However, empirical research on factors motivating GFGP participation willingness remains limited and the comparison of the influencing pathways under different compensation scenarios is lacked. In this case study of farm households’ willingness of participation in Mulan Paddock, China, based on a participatory rural appraisal with 11 sample towns and 438 valid questionnaires, the structural equation model was applied to identify key factors influencing participation in GFGP in Mulan Paddock before (2000) and after (2014) the program under different compensation scenarios (i.e. with or without subsidies). It was found that 84.28% of farm households had increased income after the implementation of the GFGP. When the government provided subsidies, the past program support would dominate the willingness to participate in the program. When the government did not provide subsidies, subjective perceptions about the ecological and economic benefits and awareness of landscape protection were further supplemented as the most important factors for household participation. Under the subsidized scenario, neighborhood behavior could enhance household participation in the GFGP, while the participation decision was negatively influenced without subsidies. The findings provide guidance for better implementation of the next round GFGPs in China, and also for investigating the correlation between PES and social welfare in other non-developed areas.
Atmospheric Pollution Research, May 2022
Keyu Luo, Zhenyu Wang, Jiansheng Wu
Abstract: Atmospheric pollution studies have linked diminished human activity during the COVID-19 pandemic to improve air quality. This study was conducted during January to March (2019–2021) in 332 cities in China to examine the association between population migration and air quality, and examined the role of three city attributes (pollution level, city scale, and lockdown status) in this effect. This study assessed six air pollutants, namely CO, NO2, O3, PM10, PM2.5, and SO2, and measured meteorological data, with-in city migration (WCM) index, and inter-city migration (ICM) index. A linear mixed-effects model with an autoregressive distributed lag model was fitted to estimate the effect of the percent change in migration on air pollution, adjusting for potential confounding factors. In summary, lower migration was associated with decreased air pollution (other than O3). Pollution change in susceptibility is more likely to occur in NO2 decrease and O3 increase, but unsusceptibility is more likely to occur in CO and SO2, to city attributes from low migration. Cities that are less air polluted and population-dense may benefit more from decreasing PM10 and PM2.5. The associations between population migration and air pollution were stronger in cities with stringent traffic restrictions than in cities with no lockdowns. Based on city attributes, an insignificant difference was observed between the effects of ICM and WCM on air pollution. Findings from this study may gain knowledge about the potential interaction between migration and city attributes, which may help decision-makers adopt air-quality policies with city-specific targets and paths to pursue similar air quality improvements for public health but at a much lower economic cost than lockdowns.
International Journal of Environmental Research and Public Health, May 2022
Jiansheng Wu, Xuechen Li, Si Li, Chang Liu, Tengyun Yi, Yuhao Zhao
Abstract: Research on urban thermal environments based on thermal comfort can help formulate effective measures to improve urban thermal and human settlement environments, which is of great significance for improving urban quality, urban climate change adaptation, and sustainable development. Taking 344 municipal administrative districts in China as study areas, the Universal Thermal Climate Index (UTCI) of each city in the last 20 years was calculated to evaluate thermal comfort. We then analyzed the thermal comfort and spatiotemporal heterogeneity of each city during a typical heat wave. Finally, the driving forces of the potential socioeconomic, natural, and landscape factors influencing thermal comfort were analyzed using geographic detectors. The results show that the thermal comfort index had similar spatial patterns and differentiation characteristics in different years, and the interannual variation was not obvious. Cities in the typical heat wave period were mainly distributed in East and Northwest China. The driving factor in the contribution rate of the same index in different years was basically the same and was not affected by the change in years, and the highest contribution rate was the natural factor.
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