Yanshan Mountains Research Articles

Characteristics and Evolutions of the Atmospheric River in the “23.7” Extreme Rainstorm Event in Hebei Province of China in July 2023

Abstract An extreme rainstorm occurred in Hebei Province, China, from July 29 to August 2, 2023. In this study, the rainfall observation data and reanalysis data are used to diagnose the evolution characteristics of the atmospheric river (AR) in this rainstorm case. The water vapor (WV) sources and transport paths are also analyzed by using the Lagrangian trajectory tracking model (namely the Flexible Particle dispersion model) and the Weather Research and Forecasting (WRF) model. The results indicate that the low-latitude AR exists throughout this rainstorm process, and it is mainly located in the Arabian Sea, the Bay of Bengal and the South China Sea. This AR event in Hebei is the result of the circulations of Typhoon Doksuri and Typhoon Khanun transporting WV to Hebei. The AR develops the most vigorously below 500 hPa and is often accompanied by a strong low-level jet. The convergence in the left front of its exit region, along with the divergence south of the upper-level westerly jet entrance, enhances the dynamic conditions that sustain the low-level shear line. Combined with the topographic uplifting effect from the Taihang and Yanshan Mountains, the coupling of upper-level jet and low-level jet provides a good circulation background for the ascending motion over the precipitation area. The WV source tracking shows that the target air parcels that substantially contribute to the heavy rainfall in Hebei come from Typhoons Doksuri and Khanun, which greatly strengthen the AR intensity and prolong the AR path. The sensitivity experiments based on the WRF model further verify the extension of the AR by Typhoons Doksuri and Khanun, as well as the fact that the AR is blocked by the Taihang and Yanshan Mountains while moving northward, forcing the WV to uplift and thus triggering the extreme rainstorm.

Quantitative Analysis of the Drivers of the Spatio-temporal Evolution of Vegetation NPP in the Beijing-Tianjin-Hebei Ecological Barrier Area

The Taihangshan-Yanshan Region is an important ecological barrier area in Beijing-Tianjin-Hebei, and it is of great importance to investigate the spatial distribution pattern and driving mechanism of net primary productivity （NPP） of vegetation for ecological restoration. The MOD17A3HGF.061 NPP dataset was obtained using the Google earth engine（GEE）, and Sen trend, coefficient of variation, partial correlation, complex correlation, and residual analysis were applied to investigate the spatial and temporal patterns of vegetation NPP in the study area and to quantitatively isolate the relative contributions of climate change and human activities. The results showed that： ① The vegetation NPP in the study area showed an overall increasing trend from 2003 to 2021, with a rate of（C-based）2.57 g·（m2·a）-1 and the distribution characteristics of "low in the surroundings and high in the middle" in the Taihangshan area, "high in the north and low in the south" in the Yanshan area, and "low in the north and low in the south" in the Yanshan area. At the same time, the spatial distribution characteristics of "low around and high in the middle" in the Taihangshan area and "high in the north and low in the south" in the Yanshan area were shown. Nearly 70% of the regions had medium or low volatility of vegetation NPP, and 80% of the regions had the opposite trend of future changes. ② The vast majority of NPP changes were positively correlated with precipitation and negatively correlated with temperature, but the significance was not strong； only 23% of the area had a strong correlation between vegetation NPP changes and meteorological factors, and it was concentrated in the central Yanshan Mountains, while the rest of the area was mainly driven by reasons other than climatic factors. ③ Potentially improved （NPPH>0） and potentially degraded （NPPH<0） areas were roughly equally distributed, but human activities played a positive role in most of the areas （79%）； 76% of the areas were dominated by human activities in the actual improved areas and 58% in the actual degraded areas, and human activities were the main factor dominating the NPP succession of vegetation in the study area. The results of this study provide an important reference for the formulation of precise vegetation ecological protection and restoration policies in the Beijing-Tianjin-Hebei ecological barrier area.

Petrogenesis and implications of the Shangzhuang Mesozoic gabbro-diorite-granite suite in Yanshan Mountains (Beijing)

Petrogenesis and implications of the Shangzhuang Mesozoic gabbro-diorite-granite suite in Yanshan Mountains (Beijing)

Hydrochemical evolution and formation mechanism of groundwater affected by human activities in Zhangxuan basin, northwest of Yanshan mountains, China.

The Zhangxuan Basin serves as an ecological barrier and water conservation area for Beijing, the capital of China. Clarifying the hydrochemical evolution of groundwater in this region is essential for the effective management of groundwater resources and the protection of ecological security. In this study, based on data regarding chemistry and level of shallow groundwater from 2016 to 2022, hydrogeochemical analysis methods and geostatistical techniques were applied to investigate the hydrochemical evolution and genesis mechanisms of groundwater under the influence of human activities. The results showed that: (1) From 2016 to 2022, the groundwater remained predominantly characterized by Ca2+ and HCO3-, with the primary hydrochemical type unchanged as HCO3-Ca·Mg. (2) From 2016 to 2022, an overall decreasing trend in hydrochemical components was observed, alongside an increase in HCO3-Na type groundwater. Spatially, along the direction of groundwater flow, a general trend of increasing hydrochemical components was noted, with a significant rise in HCO3-Na type groundwater. (3) The spatiotemporal distribution and evolution of hydrochemistry were influenced by water-rock interactions, lithological characteristics, groundwater flow patterns, and human activities. Along the groundwater flow direction, lithological particles became finer, enhancing forward cation exchange and leaching, with the dissolution of silicate and carbonate minerals intensifying. In localized areas, the hydrochemical components were influenced by the extraction of groundwater source areas and the discharge of industrial waste.

Quantitative reconstruction of sedimentary processes, provenance, and binary sources in Horqin Sandy Land, NE China: An integrated approach

Quantitative reconstruction of sedimentary processes, provenance, and binary sources in Horqin Sandy Land, NE China: An integrated approach

Crustal Azimuthal Anisotropy in Eastern North China Derived from Ambient Noise Tomography

Abstract Investigating the crustal anisotropy features of eastern North China is of great significance for understanding the tectonic deformation mechanisms and the shallow response to the destruction of the North China Craton. We apply ambient noise tomography to determine the Rayleigh-wave phase velocity and azimuthal anisotropy at 8–35 s periods in eastern North China. The results show significant heterogeneity in crustal velocity and anisotropy. The short-period velocity and anisotropy are primarily related to surface structures. The pronounced anisotropy observed between the basin and uplifts, with the fast axis aligning parallel to the boundary strike, is likely attributed to the velocity and topographic contrasts. The fast axis orientation within the Bohai Bay basin exhibits northwest–southeast to north-northwest–south-southeast directions in the northern part and nearly east–west direction in the southern part, showing different deformation patterns within the basin. Strong anisotropy and sharp changes in fast axis orientation are observed in focal areas of three major earthquakes, suggesting a correlation between the genesis of strong earthquakes and the anisotropy features. The fast axis in the Yanshan Mountains aligns nearly east–west in the west to east-northeast–west-southwest in the east, likely related to the extensional tectonic environment in North China. At longer periods, the anisotropy strength decreases and fast axis orientation changes, indicating that the northwestern part of the Yanshan Mountains is influenced by the residual magmatism beneath the Quaternary volcanoes. The fast axis along the Tanlu fault zone (TLFZ) is generally oriented northeast–southwest at all periods, consistent with the fault’s strike. The anisotropy features provide evidence for the TLFZ cutting through the crust and uppermost mantle. The fault activity is currently dominated by strike-slip motion. The inconsistent anisotropy patterns in the crust and upper mantle suggest that the deformations in the crust and mantle are possibly decoupled.

Migration and natural attenuation of leachate pollutants in bedrock fissure aquifer at a valley landfill site

Migration and natural attenuation of leachate pollutants in bedrock fissure aquifer at a valley landfill site

How Geomorphology Maps the Dispersal Barriers of Large Herbivorous Mammals in China

ABSTRACTAimLiterature and fossil records document the long‐term occurrence sites of large herbivorous mammals in China. These sites exhibit spatially uneven distribution, potentially reflecting constraints on the dispersal of large herbivorous mammals imposed by stable geomorphic factors. In this study, we examine the impact of landforms on the dispersal of four taxa of large herbivorous mammals across China.LocationChina.TaxonRhinocerotidae, Elephantidae, Equus, Camelus.MethodsWe employed the Omniscape algorithm to create a connectivity model from geomorphic data (slope, elevation and ground cover), assessing the extent to which Chinese landforms obstruct large herbivore dispersal. This model utilised historical distribution sites to delineate barrier strips.ResultsDispersal barriers show regional variation, segmenting China into four distinct regions. The Tibetan Plateau, Taklamakan Desert and Qinling Mountains constitute Region A, presenting the most significant barrier. Region B, characterised by dense, continuous mountain ranges and arid landforms in Northwest China, poses a secondary barrier. Region C, with fragmented mountain ranges in Southwest China, exhibits a diminished barrier effect. Region D features the eastern coastal plains with minimal geomorphic constraints.ConclusionsThe edge mountains of the Tibetan Plateau form a continuous barrier strip. The Qinling–Taihang–Yanshan mountain chain constitutes a discontinuous barrier strip. This is because the mountain chain belongs to two geological structural units and is eroded by rivers, creating many corridors.

Patterns of Species Richness and Its Endemism of Beetles in the Beijing–Tianjin–Hebei Region of China

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.

National-scale 10 m annual maize maps for China and the contiguous United States using a robust index from Sentinel-2 time series

National-scale 10 m annual maize maps for China and the contiguous United States using a robust index from Sentinel-2 time series

Multi-parameters monitoring of geological disasters around the Taihang Mountains-Yanshan area, Hebei Province

The Hebei Taihang Mountains-Yanshan region marks North China’s natural boundary between plains and plateaus. The unique geological and geographical conditions have led to a hazardous environment with frequent geological events. Hence, conducting a comparative analysis of regional geological hazard drivers is necessary. A geological hazard driver analysis model using multiparameter preferential Geodetectors was developed, focusing on the Taihang Mountains-Yanshan region in Hebei. It was divided into zones: Taihang Mountains, Yanshan Mountains and Dam Plateau. The results showed significant differences in the explanatory power of geohazard drivers in various zones, varying with the softening of the natural geological environment and increased human activities. In the Taihang Mountains, the primary geohazard factor is average annual rainfall, whereas in the Yanshan Mountains, it is average annual rainfall and geomorphology. Interactions among factors reveal that annual average rainfall holds the highest explanatory power for geological hazard spatial differences, notably interacting with geomorphological, geological and human activity regions, yielding an escalating effect. The study findings can be crucial references for disaster prevention, mitigation, national land resource development, economic planning and the ‘six belts’ construction in Beijing, Tianjin and Hebei.

Comparison of Three Approaches for Estimating Understory Biomass in Yanshan Mountains

Aboveground biomass (AGB) of shrubs and low-statured trees constitutes a substantial portion of the total carbon pool in temperate forest ecosystems, contributing much to local biodiversity, altering tree-regeneration growth rates, and determining above- and belowground food webs. Accurate quantification of AGB at the shrub layer is crucial for ecological modeling and still remains a challenge. Several methods for estimating understory biomass, including inventory and remote sensing-based methods, need to be evaluated against measured datasets. In this study, we acquired 158 individual terrestrial laser scans (TLS) across 45 sites in the Yanshan Mountains and generated metrics including leaf area and stem volume from TLS data using voxel- and non-voxel-based approaches in both leaf-on and leaf-off scenarios. Allometric equations were applied using field-measured parameters as an inventory approach. The results indicated that allometric equations using crown area and height yielded results with higher accuracy than other inventory approach parameters (R2 and RMSE ranging from 0.47 to 0.91 and 12.38 to 38.11 g, respectively). The voxel-based approach using TLS data provided results with R2 and RMSE ranging from 0.86 to 0.96 and 6.43 to 21.03 g. Additionally, the non-voxel-based approach provided similar or slightly better results compared to the voxel-based approach (R2 and RMSE ranging from 0.93 to 0.96 and 4.23 to 11.27 g, respectively) while avoiding the complexity of selecting the optimal voxel size that arises during voxelization.

Effects of Orography on the High-Temperature Event on 22 June 2023 in North China

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.

SHRIMP zircon U-Pb ages of the tuffite beds in the Tuanshanzi Formation (Changcheng Group) of the Yanshan Mountains, North China Craton

SHRIMP zircon U-Pb ages of the tuffite beds in the Tuanshanzi Formation (Changcheng Group) of the Yanshan Mountains, North China Craton

Optically stimulated luminescence dating of Paleolithic sites reveals population shifts in North China during the last glacial period

Optically stimulated luminescence dating of Paleolithic sites reveals population shifts in North China during the last glacial period

Recent Northward Expansion of a Passerine Bird Species, Brownish-Flanked Bush Warbler (Horornis fortipes).

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.

Diversity and taxonomy of the genus Amanita (Amanitaceae, Agaricales) in the Yanshan Mountains, Northern China.

Globally, the species of Amanita are key components of ectomycorrhizal ecosystems. Some of them are widely known as poisonous or edible fungi. Although many new Amanita species from China have been described, the species diversity of Yanshan Mountains remains unknown. We here describe three new species, namely, A. borealis sp. nov. (Sect. Amanita), A. brunneola sp. nov. (Sect. Caesareae), and A. yanshanensis sp. nov. (Sect. Validae), based on morphological observations and molecular phylogenetic analyses. In addition, nine known species, namely, A. caesareoides (Sect. Caesareae), A. chiui (Sect. Vaginatae), A. muscaria (Sect. Amanita), A. oberwinklerana (Sect. Roanokenses), A. ovalispora (Sect. Vaginatae), A. subglobosa (Sect. Amanita), A. subjunquillea (Sect. phalloideae), A. vaginata var. vaginata (Sect. Vaginatae), and A. virosa (Sect. phalloideae), were reported from Yanshan Mountains for the first time. Our results emphasize that China has a high diversity of Amanita species and that additional studies are required to understand the exact species number. These findings play a crucial role in Amanita toxin research and ecological conservation. This study investigated the areas where Amanita species-related research is lacking. The study also attempted to better understand Amanita distribution and thus contribute to related research. This study enriches the species diversity of Amanita in Yanshan Mountains and offers additional data supporting the macrofungal systematics, toxin research, and diversity and ecological studies of Amanita in future studies.

A new species of Russula subgenus Russula (Russulaceae, Russulales) from Yanshan Mountains, North China

A new species of Russula subgenus Russula, Russula pseudosinoparva, is described from the Yanshan Mountains in northern China based on morphology and phylogenetic analysis of the nrITS and nrLSU-rpb2-mtSSU-tef1α gene regions. Russula pseudosinoparva is characterized macroscopically by small basidiomata with a dark red to dark pink pileus; lamellae usually forked near the stipe, with a small number of lamellulae; and microscopically by a suprapellis made up of loose and upright hyphae. Phylogenetic and morphological analyses placed the new species in the lineages of subsect. Puellarinae. As well as an illustrated description we provide a key to the species of Russula subgenus Russula distributed in China.

Continuous crustal thinning of the North China Craton in the Early Cretaceous: Evidence from A-type granites

Widespread crust-derived granitoids in North China provide evidence of Mesozoic lithospheric thinning and destruction of the North China Craton. However, the link between lower crust and lithospheric mantle reactivation remains poorly understood. We present whole-rock geochemistry and zircon O-Hf isotopes for Early Cretaceous peralkaline A-type granites (i.e., Xiwanzi, Xiangshan, and Yansehu) from the Yanshan Mountains of the eastern block of the North China Craton. The Xiwanzi granite has a U-Pb age of 134.3 ± 0.4 Ma, with homogeneous whole-rock Nd isotopes [εNd(t) = −7.7 to −7.5] but highly variable zircon O-Hf isotopes [δ18O = 5.1‰ to 7.2‰ and εHf(t) = −7.7 to +9.6]. Such isotopic variations likely resulted from a hybrid juvenile source consisting of partial melting of newly underplated basaltic rocks derived from both the metasomatized ancient and juvenile sub-continental lithospheric mantle. In contrast, the Xiangshan (117.4 ± 1.0 Ma) and Yansehu (116.3 ± 1.4 Ma) granites have relatively uniform isotopic compositions [whole-rock εNd(t) = −12.2 to −10.8, zircon δ18O = 5.2‰ to 6.4‰, and εHf(t) = −17.1 to −4.7], close to those of the Proterozoic mafic granulite xenoliths from the ancient lower crust. The isotopic variations of the Early Cretaceous A-type granites suggest a continuous change in the melting model from the underplated juvenile lowermost crust to the overlying ancient lower crust at high temperatures in an extensional environment. Our results indicate that A-type granites can be used to probe the nature and reactivation of the lower crust of an Archean craton. Significantly, large-scale continuous thinning of lower continental crust provides key insights into the generation of the widespread Mesozoic crust-derived granitoids in North China.

Superimposed effects of typical local circulations driven by mountainous topography and aerosol–radiation interaction on heavy haze in the Beijing–Tianjin–Hebei central and southern plains in winter

Abstract. Although China's air quality has substantially improved in recent years due to the vigorous emissions reduction, the Beijing–Tianjin–Hebei (BTH) region, especially its central and southern plains at the eastern foot of the Taihang Mountains, has been the most polluted area in China, with persistent and severe haze in winter. Combining meteorology–chemistry coupled model simulations and multiple observations, this study explored the causes of several heavy haze events in this area in January 2017, focusing on local circulations related to mountain terrain. The study results showed that on the weather scale, the configuration of the upper, middle, and lower atmosphere provided favorable weather and water vapor transport conditions for the development of haze pollution. Under the weak weather-scale systems, local circulation played a dominant role in the regional distribution and extreme values of PM2.5. Influenced by the Taihang and Yanshan mountains, vertical circulations and wind convergence zone were formed between the plain and mountain slopes. The vertical distribution of pollutants strongly depended on the intensity and location of the circulation. The circulation with high intensity and low altitude was more unfavorable for the vertical and horizontal diffusion of near-surface pollutants. More importantly, we found that the aerosol–radiation interaction (ARI) significantly amplified the impacts of local vertical circulations on heavy haze by two mechanisms. First, the ARI strengthened the vertical circulations at the lower levels, with the zonal wind speeds increasing by 0.3–0.8 m s−1. Meanwhile, the ARI could cause a substantial downward shift in the vertical circulations (∼ 100 m). Second, the ARI weakened the horizontal diffusion of pollutants by reducing the westerly winds and enhancing wind convergence and southerly winds. Under these two mechanisms, pollutants could only recirculate in a limited space. This superposition of the typical local circulation and the ARI eventually contributed to the accumulation of pollutants and the consequent deterioration of haze pollution in the region.