Search Results (19)

The extreme rainstorm flood disaster in Beijing on 31 July 2023 resulted in 33 fatalities and 18 missing persons, with direct economic losses across the Beijing–Tianjin–Hebei metropolitan area exceeding RMB 10 billion. Despite its inland location, which is not conventionally classified as a flood-prone zone, Beijing is not conventionally considered a flood-prone region, yet it frequently experiences flood disasters, which has led to confusion and perplexity. This article collects records of historical flooding disasters in Beijing over the past 1000 years, spanning the Jin, Yuan, Ming, and Qing dynasties, the Republics of China, and the founding of New China up to the present, aiming to analyze the basic patterns and characteristics of regional historical flooding disasters. Taking the extreme rainstorm flood disaster in Beijing on 31 July 2023 as an example, this research employs a multidisciplinary approach, including field investigations and numerical simulations, to dissect the disaster-causing mechanisms. The study shows that the significant characteristics of historical flood disasters in Beijing are concentrated in the plain area and the high-frequency outbreaks (below the 3-year return period). Flood disaster events under the participation of typhoons accounted for a high proportion and caused great harm. The extreme rainstorm flood disaster in Beijing on 31 July 2023 was an extreme weather event under the complex coupling of typhoons and terrain. The residual typhoon circulation stayed on the mainland for nearly 70 h, providing abundant precipitation conditions for Beijing. Water vapor is blocked by the Yanshan–Taihang Mountains, uplifting and converging, forming a strong precipitation center in the Piedmont, which aggravates the regional local precipitation intensity. The research results can provide a reference for the scientific prevention and control of typhoon rainstorm flood disasters in Beijing. Full article

With rapid economic development and the change in land use patterns, the region faces the environmental challenge of increasing carbon emission risk. The research on analyzing and identifying carbon emission risk of land use is helpful to realize regional sustainable development. This study takes the Yanshan-Taihang Mountain area of Hebei Province as a case study. Based on the remote sensing monitoring data of land use in 2010, 2015, and 2020, the carbon emissions of land use are calculated by direct and indirect calculation methods. Then, the carbon footprint pressure index and land use carbon emission risk index are introduced to analyze the temporal and spatial differentiation characteristics of land use carbon emission risk in the study area. The findings indicate that carbon emissions associated with land use in the study area initially exhibited an increasing trend, followed by a subsequent decline over time. In space, the high-value areas of carbon emissions are mainly distributed in the south of the study area, and the low-value areas of carbon emissions are mainly concentrated in the northeast of the study area. The region experiences significant carbon-cycling pressure and environmental risk, with the proportion of counties in carbon balance areas decreasing from 27.27% in 2010 to 18.18% in 2020, and the proportion of counties in carbon imbalance areas increasing from 72.72% in 2010 to 81.82% in 2020. The carbon emission risk of land use is divided into micro-risk area, low-risk area, medium-risk area, high-risk area, and severe-risk area. From 2010 to 2020, there was an 18.18% increase in the percentage of counties classified as high-risk and severe-risk areas. Additionally, the regions identified as hotspots for land use emissions exhibited a trend in expansion. This phenomenon indicates that these areas have not successfully managed to mitigate environmental pollution or ensure the sustainable use of resources in the context of their economic development efforts. This series of dynamic changes shows that the study area is facing the challenge of increasing carbon emission risk from land use. Governments at all levels should strengthen environmental governance in high-risk areas, implement stricter land use policies, and promote green development and cleaner production to attain a mutually beneficial outcome for both economic development and ecological protection. Full article

Ecological importance evaluation can clearly identify the ecological service functions and ecological values of a region. This paper takes the Yanshan-Taihang Mountain area in Hebei Province as the research area, utilizing 2020 land use data. With the help of various analytical models and GIS spatial analysis methods, this paper selects water conservation, soil and water conservation, biodiversity, carbon sequestration and oxygen release to evaluate the importance of ecosystem services, and selects soil and water loss sensitivity and land desertification sensitivity to evaluate the ecological sensitivity, so as to identify the important areas of ecological protection in the study area, analyze their spatial change characteristics and divide the leading ecological functions according to the results. The results show that the moderately important and highly important areas in the Yanshan-Taihang region of Hebei Province account for more than 70% of the total study area. Based on the importance evaluation results, three types of dominant ecological function zones were obtained using self-organized feature mapping neural network analysis in the R language, and control measures were proposed. The research results can provide strategic support for local ecological protection and regional ecological restoration, as well as serving as a reference for the optimization of land spatial development patterns. Full article

The Beijing–Tianjin–Hebei region lies between the Mongolia-Xinjiang Zoogeographic Region and the Central China Zoogeographic Region in China, harboring relatively rich biodiversity. This study specifically examined the species diversity, richness and endemic areas of beetles in this area. By analyzing 5965 detailed distribution records of 2047 beetle species in the Beijing–Tianjin–Hebei region, the species richness maps were created with a grid size of 0.5°. Additionally, two methods, parsimony analysis of endemism (PAE) and endemicity analysis (EA) were applied to detect areas of endemism (AOEs) with different grid sizes (0.1°, 0.25° and 0.5°), resulting in the identification of three AOEs in the southern mountainous areas of the Taihang Mountains, Yanshan Mountains, and Xiaowutai Mountains. It also verified that AOEs are consistent with the hypothesis that endemic areas are predominantly located in mountain ranges, as proposed by previous related studies. These findings highlight the importance of complex topography and stable climate in shaping AOEs and conserving biodiversity. Full article

An extreme high-temperature event occurred in North China on 22 June 2023, with the maximum temperature reaching 41.8 °C. The high-temperature centers preferentially occurred at the foothills of the Taihang and Yanshan Mountains, indicating an important role of the underlying orography. In the present work, we study the orographic effects of this extreme high-temperature event according to high-resolution numerical simulations using the Weather Research and Forecasting model. The results show that the presence of the mountains in North China contributed notably to the high-temperature event, which can enhance the 2 m air temperature by up to 3 °C. In the daytime, the enhancement of temperature is primarily due to the diabatic heating of sensible heat flux at the terrain surface caused by solar shortwave radiation, whereas the well-known foehn effect has little contribution. Indeed, the dynamically forced downslope flow of foehn is totally suppressed by the upslope flow of the thermally driven mountain-plain circulation. In the nighttime, the sensible heat flux at the terrain surface changes to weakly negative, given the cooling of land surface longwave radiation. As a result, the enhancement of near-surface temperature at the terrain foothill is dominated by the adiabatic warming of downslope flow. Yet, the near-surface temperature far away from the mountain is enhanced by the subsidence warming of a synoptic anomalous anti-cyclone, which is induced by the diabatic heating over the mountains in the daytime. These findings help improve the understanding of the thermal and dynamical effects of orography on the occurrence of high-temperature events. Full article

As the construction of photovoltaic power plants continues to expand, investors have placed great importance on the suitability assessment of site selection. In this study, we have developed a multi-level evaluation system and proposed an AHP–XGBoost–GIS comprehensive evaluation model for assessing site suitability in the Beijing–Tianjin–Hebei region. The findings revealed that approximately 48,800 km² (21.59% of the total area) constituted a suitable area in this region, surpassing previous research results. Generally suitable areas accounted for the largest proportion at 35.89%. Suitable areas in Beijing and Tianjin were relatively limited, with most of them concentrated in Baoding City, Zhangjiakou City, and Chengde City on the northwest side of the “Yanshan-Taihang Mountains”, where there are ample wastelands with gentle slopes conducive to constructing photovoltaic power plants southeast of the “Yanshan-Taihang Mountains”, and solar radiation conditions were better. However, ecological and economic factors restricted suitable areas resulting in smaller coverage including cities such as Handan, Xingtai, Qinhuangdao, and Tangshan, among others. This study successfully overcame limitations associated with traditional subjective evaluation methods by providing decision support for regional energy allocation planning and spatial planning efforts, as well as environmental protection endeavors. Full article

Northward expansions of bird distributions have been commonly observed in the Northern Hemisphere, likely as a result of climate change. The causes and ecological impacts of such range shifts have received extensive attention, but studies on the process of range shifts are still relatively scarce. The Brownish-flanked Bush Warbler (Horornis fortipes) has expanded northward from 35° N to 40° N during the past decade. In this study, we collated 77 records of the species beyond its traditional distribution during the past ten years from citizen science data. Most of the new records were from northeast of its traditional distribution, including the North China Plain, Taihang Mountains, and Taishan Mountain, and a few records from the northern margin of the Qinling Mountains and Qinghai–Tibet Plateau. We concluded that the Brownish-flanked Bush Warbler has bred in this new area in at least six sites. The newly established populations are assumed to belong to the subspecies H. f. davidianus, which can be divided into eastern and western dialect groups based on differences in songs. Song recordings from 10 males from Beijing and its adjacent areas were collected. Bayesian analysis based on the acoustic traits indicated that these males were most likely from the western dialect area, with a posterior probability of 99.975%. Combining topographical data with the habitat preference of the species, we inferred that these individuals spread northeastward from the Qinling Mountains to Taihang Mountains, and further along the Yanshan Mountains. This study is a case study of the distribution expansion of a bird species, which reflects the dynamics of a species in the early stage of its northward expansion. Full article

Rural China has undergone a rapid transformation in the past few decades, especially the poverty-stricken areas, making a historic leap from inadequate subsistence to full well-off status. Based on rural regional system theory, this study analyzes the connotation of rural transformation development (RTD), explores the spatio-temporal patterns of RTD in the Yanshan-Taihang Mountainous, and diagnoses its influencing factors using a geographically and temporally weighted regression model. The results show that RTD is a dynamic process of qualitative changes in rural regional systems based on the accumulation of quantitative changes of elements, and the key to its measurement lies in analyzing the coupling coordination degree between quantitative changes of elements. From 2000 to 2020, the rapid development of urban population share, non-agricultural industry share, construction land share and NDVI in the Yanshan-Taihang Mountains contributed to a leap in RTD status, and the proportion of counties in a coupling coordination state increased from 24.24% to 96.97%. Spatially, the RTD level in the Taihang Mountains was significantly superior to that in the Yanshan Mountains. Average years of schooling, road density, per capita GDP and urban–rural dual structure were the main influencing factors of RTD, of which the first three were positive factors and the last one presented a negative correlation. To promote RTD to a higher level, it is an urgent matter to boost the high-quality development of county economy and rural education, improve public transportation infrastructure and innovate the policy system. Full article

This study aims to explore the evolution of the pattern of ecological environment quality and its driving factors in the Beijing-Tianjin-Hebei (BTH) region, providing a basis for developing regional ecological protection policies. Based on remote sensing image data, the study developed a remote-sensing eco-environmental index (REI) from two dimensions, namely ecological quality and environmental quality, and evaluated the spatiotemporal changes of the eco-environment quality in the BTH region from 2000 to 2020. The main factors affecting the eco-environment quality and the changing trend of the eco-environment quality were subsequently analyzed using the geographic detector model and the GM1.1 model. The results show that the eco-environmental quality of the BTH region shows a fluctuating downward trend and distinct regional differences during the study period. The Yanshan Mountain in the north and the Taihang Mountain in the west have high ecological quality, while the Zhangjiakou area in the northwestern part of Hebei Province and the urban center in the southeastern part of Hebei Province suffer low ecological quality. Natural factors played a dominant role in influencing eco-environmental factors, but the proportion of economic and social factors increased over time. It is predicted that the number of counties in the region with poor eco-environmental factors will increase significantly. Therefore, the comprehensive assessment of regional ecological quality can be effectively achieved based on REI, thus providing a reference for the green and high-quality development of the regional social economy. Full article

Clarifying the interrelationship between climate and land use/land cover (LULC) changes on water yield in mountainous areas is very urgent due to the dramatic decrease in the water availability of mountainous areas. In this study, the InVEST model was used to calculate the water yield of the mountainous area in Beijing–Tianjin–Hebei region (BTH) from 1980 to 2020, and six scenarios were designed to identify the contribution rates of climate and LULC change on the water yield. The results showed that, in 1980–2020, the water yield in the mountainous area of BTH was the largest in 1990, at 377.95 mm and the smallest in 1980, at 150.49 mm. After 2000, the interannual water yield showed a slightly increasing trend, which was significantly lower than the water yield in 1990, the values ranging from 217.01 mm to 324.65 mm. During the study period, the spatial distribution of the water yield was similar over the years, with high values in the south-central Taihang Mountain (THM) and the northeastern Yanshan Mountain (YSM). The THM was the main water yield area of the mountainous area in BTH. The annual water yield of farmland was the highest, followed by forest land and grassland, while the proportion of volumetric water yield was the largest in forest land with an increasing trend from 1980 to 2020 and the grassland showed a decreasing trend, while that of farmland increased first from 1980 to 2000 and decreased from 2000 to 2020. Climate is the key factor controlling the water yield of the mountainous area in BTH from 1980–2000, 2000 to 2020, and 1980 to 2020. In the period of 2000–2020, the effect of LULC on the water yield is negative, while the effect is positive in 1980–2000 and 1980–2020. The contribution rate of climate to the water yield increases in the THM, Bashang region (BSR) and YSM from the period 1980–2000 to 2000–2020, while that of LULC in those three regions changes from a positive impact in 1980–2000 to a negative impact in 2000–2020, and the contribution rate is also greatly reduced. In the long term, land revegetation will gradually benefit the water yield in the mountainous areas of BTH, including the THM, BSR, and YSM. These results can provide an important scientific and technological reference for the ecological management and protection of water source sites, as well as the planning and utilization of water resources in mountainous areas of BTH. Full article

Ecosystem services are closely related to human wellbeing—which refers to the basic material conditions required to maintain high standards of quality of life, of health, and of safety and security, as well as good social relationships, and freedom of choice and action—and have a high potential value. The adequate valuation of ecosystem service values (ESV) is now an urgent need for the implementation of policy measures such as ecosystem asset management, ecological compensation and paid use of ecosystem services. Based on the method of ecosystem value equivalent factor per unit area, in this paper we investigated the variability of total ESV spatial distribution and regional differences in the value of 11 ecosystem service types provided by ecosystems in the mountainous areas of the Beijing–Tianjin–Hebei (BTH) region at different spatial scales and discussed the relationship between ESV and land use land cover (LULC). The results show that the total ESVs in 2015 and 2020 in the mountainous areas of BTH region were 5671 × 10⁸ CNY and 6381 × 10⁸ CNY, respectively. The change trend of each ecosystem service value from 2015 to 2020 was dominated by an increase of water supply service, and the maintenance of soil and nutrient cycle services in the mountainous area of BTH and the Yanshan Mountain (YSM). The change patterns of the value of ecosystem service categories in the Taihang Moutain (THM) and Bashang region (BSR) are dominated by an increase in the value of maintained soil and water supply services and a decrease in the value of regulating services. The calculation of ESV can be made more accurate by considering climate and vegetation conditions at the region, ecosystem, county or township scales rather than at grid scale, as, for calculating the interannual variation of total ESV, the spatial scale variability is large. The assessment of ESVs is important from the point of view of planning the use of the environment, of spatial planning, and of nature conservation. The ecosystem service of woodland and water bodies are more prominent compared with other land-use types and construction land and bare land provide the lowest value of service. There is some similarity between the value changes of ecosystem service categories and the distribution of LULC types. This study strengthens the understanding of the spatial scales of different ESV in mountain areas, which is beneficial to ecosystem management policies. Full article

Oaks (Quercus spp.) are considered model plants for studying plant evolution and natural gene introgression. Beijing area is at the junction between Taihang Mountain and Yanshan Mountain, and it is an overlapping distribution area of several deciduous oaks native to China. Interspecific hybridization often occurs in sympatric sibling species, resulting in blurred interspecific boundaries and hindering the development of breeding. To have better improvement and protection of these oaks, it is urgently necessary to evaluate the genetic diversity and population structure of these oak species. In this study, we collected eleven populations of four oak species (Q. variabilis, Q. mongolica, Q. dentata and Q. aliena) in the Beijing area. By using the polymorphic SSR markers, we analyzed the genetic variation of the collected 400 individuals, investigated the population structure, and found gene introgression events. Q. variabilis had a clearer genetic background as compared to the other three species. Q. mongolica had a more frequent gene introgression with Q. dentata and Q. aliena. Our data reveal the introgression and genetic diversity of the four oak species native to the Beijing area, laying the foundation for conducting an oak germplasm nursery with a clear genetic background for protection and further improvement. Full article

National key ecological function zones (NKEFZs) in China are critically important to maintain ecological security and accelerate the construction of the ecological civilization system. The quantitative impact of NKEFZs on green development at the county level has not received much attention. In this study, the county-level statistics of the Yanshan–Taihang Mountainous area in Hebei province from 2013 to 2018 were selected as samples. The symbiotic relationship between economy and ecology was measured and development patterns were identified using an improved Lotka–Volterra model. Then, a difference-in-differences (DID) model was used to empirically test the green development effects of establishing NKEFZs, as well as the dynamic changes of the effects and the heterogeneity of different development patterns. The results show that: (1) Green development in the sample area can be classified into four patterns: Low-High, High-Low, High-High, and Low-Low; (2) NKEFZs reduce the level of green development in the study interval and have a persistent negative effect on the level of green development; and (3) NKEFZs have a significant negative effect on areas of Low-High and High-Low development patterns, while the effect on areas of Low-Low development patterns is not significant. Overall, the results indicate that NKEFZs have a negative impact on the green development of the Yanshan–Taihang Mountainous area in Hebei Province. Finally, to promote green development in mountainous areas, the paper makes the following recommendations: Firstly, to improve the transfer payment system for NKEFZs and bring into play a long-term mechanism for the compensation effect of transfer payments. Secondly, to cultivate special industries to achieve the differentiated development of county economies. Thirdly, to accelerate the optimization and adjustment of industrial structures and promote the coordinated development of primary, secondary, and tertiary industries. Full article

China’s “plain–mountain transition zone” (hereinafter referred to as the “transition zone”) has experienced rapid and diverse urbanization processes. Assessing the dynamic characteristics of urbanization is particularly important for sustainable development of the transition zone. Nighttime light (NTL) data have been widely used to monitor urbanization. Based on the prolonged artificial nighttime-light dataset of China (PANDA) from 1984 to 2020, we partitioned the nighttime light of the study area into four types (low, medium, high, and extremely high) by adjusting the threshold of the brightness gradient (BG) method. The spatiotemporal characteristics of urbanization in 426 districts and counties of 71 prefecture-level cities in the transition zone were analyzed. Our results indicated that the middle region of the transition zone (Yanshan Mountains and Taihang Mountains) experienced the fastest urbanization development, and the urban expansion speed broke through the topographic limitation of the plain–mountain. However, the rapid development of urbanization in the middle plains resulted in the nighttime lighting area (NTLA) tending to become saturated, which caused an unsustainable potential crisis in urban development in this area. Urbanization was mainly manifested in the transition of the low nighttime lighting type (NTLT) to the medium NTLT or higher NTLT. The northern region of the transition zone (Greater Khingan Mountains) experienced the slowest urbanization development, with the lowest nighttime lighting density (NTLD) in the northern mountainous area, where the urbanization was mainly manifested by the expansion of the low NTLT. The urbanization development of the southern region in the transition zone (Wushan and Xuefeng Mountains) was at a medium level, and the urbanization of the plain in the southern region was also better than that of the mountainous area. Urbanization was mainly manifested in the expansion of the low NTLT, supplemented by the transition from the low NTLT to high NTLT. Whether in the north, middle, or south of the transition zone, the plain–mountain topographic variations caused a gap in urbanization, making the urbanization development of the mountains and plains unbalanced. Full article

The contradiction between urban expansion and ecological protection in the Beijing-Tianjin-Hebei region (BTH) is increasingly acute, which has become one of the main problems restricting regional development, and sustainable development of ecosystem services is the key to increasing human well-being. Based on GIS platform and multiple models, this paper analyzes the temporal and spatial variation characteristics of four key ecosystem services (water conservation, soil conservation, habitat quality, and plant net primary productivity) in different ecological regions of BTH in recent 20 years, quantifies the impact of different climate factors and land use change on ecosystem services (ESs), and discusses the primary ecosystem hotspots and ecological security pattern. The results showed that the interannual variation of water conservation (WC) and plant net primary productivity (NPP) increased from 2000 to 2020, while the change of soil conservation (SC) was not obvious, which was mainly controlled by climate factors, WC and SC were more affected by precipitation, and temperature was the key factor affecting NPP. Habitat quality (HQ) presented a significant downward trend; it was mainly attributed to the deterioration of ecological environment caused by accelerated urbanization expansion. According to hotspot analysis, it could be found that WC was the fastest-growing ecosystem service function in BTH, and NPP would become the factor with the greatest contribution to ecological importance in the future. The important protected areas and main ecological sources of ecological security pattern were mainly distributed in Yanshan-Taihang mountain area, which was consistent with the key areas of ecosystem services. In this study, the temporal and spatial differences of ecosystem service in BTH were demonstrated in a more intuitive way and provided scientific guidance for decision makers to formulate effective ecological protection policies in different regions. Full article