Qinghai Tibet Research Articles

Distribution and changes of thermokarst lakes along the Qinghai-Tibet Railway from 1991 to 2022

Permafrost degradation on the Qinghai–Tibet Plateau has led to the rapid development of thermokarst lakes, but their distribution along the Qinghai-Tibet Railway (QTR) has not been fully studied. In this study, we established the Landsat, Sentinel-2A and GF-1 image datasets and a 50 ​km wide transect along the QTR, and used ENVI software to extract lake data. The distribution characteristics of thermokarst lakes at different distances from the QTR in 2022 were analyzed. The spatiotemporal evolution of thermokarst lakes and their relationship with climatic factors from 1991 to 2022 were examined. The results showed that, from 1991 to 2022, the number and area of thermokarst lakes in the study area increased by about 3,892 and 70.08 ​km2, respectively. It was found that climate warming and intensified precipitation are the main reasons for the increase in the number and area of thermokarst lakes in the study area. This study provides basic support for an in-depth understanding of the long-term interannual changes of the thermokarst lakes along the QTR and the maintenance of the QTR.

Dynamic changes of gravity field before the Luding MS6.8 earthquake and its crustal material migration characteristics

On September 5, 2022, an earthquake of magnitude MS6.8 occurred in Luding County, Sichuan Province. This earthquake occurred at the key part of the southeast-clockwise extrusion of material on the eastern margin of the Qinghai–Xizang Plateau, the Y-shaped confluence of the Xianshuihe, Longmenshan and Anninghe fault zones. In this study, the three-dimensional dynamic crustal density changes in the earthquake area are obtained by the typical gravity change data from 2019 to 2022 before the earthquake and gravity inversion by growing bodies. The results indicate that gravity changes presented an obvious four-quadrant and gradient belt distribution in the Luding area before the earthquake. The three-dimensional density horizontal slices show that small density changes occurred at the epicenter in the mid-to-upper crust between 2019.9 - 2020.9 and 2019.9–2021.9. At the same time, the surrounding areas exhibited a positive and negative quadrant distribution. These observations indicate that the source region was likely in a stable locked state, with locking-in shear forces oriented in the NW and NE directions. From 2021.9 to 2022.8, the epicentral region showed negative density changes, indicating that the source region was in the expansion stage, approaching a near-seismic state. The three-dimensional density vertical slices reveal a southeastward migration of positive and negative densities near the epicenter and on the western of the Xianshuihe Fault Zone, indicating that the material is flowing out to the southeast. The observed local negative density changes at the epicenter along the Longmenshan Fault Zone are likely associated with the NE-oriented extensional stress shown by the seismic source mechanism. The above results can provide a basis for interpreting pre-earthquake gravity and density changes, thereby contributing to the advancement of earthquake precursor theory.

Petrogenesis of early Paleozoic syn-collisional granitoids and enclaves in Western Kunlun, Northwest China: Implications for the growth of continental crust

The Western Kunlun Orogenic Belt (WKOB), along the northwestern margin of the Qinghai–Xizang Plateau, was formed by the collision of Gondwana-derived terranes to the south and the Tarim Block to the north and was closely associated with closure of the Proto-Tethys Ocean during the late Neoproterozoic to early Paleozoic. We present a combined zircon UPb geochronology, whole-rock composition, and Sr–Nd–Hf isotopic study of syn-collisional granitoid plutons and mafic microgranular enclaves (MMEs) in the region. Zircon UPb dating yields ages of 443.8 ± 4.4, 451.9 ± 4.2, 462.9 ± 3.5, and 456 ± 4.2 Ma for the Tongayoupuagezi, Shanjie, and Pishigai plutons and MMEs from the Pishigai pluton, respectively. The granitoids are metaluminous to weakly peraluminous (A/CNK = 1.00–1.17) and belong to the high-K calc-alkaline series. They have (87Sr/86Sr)i ratios of 0.7058–0.7154, εNd(t) values of −8.78 to −0.93, and εHf(t) values of −19.72 to +6.87. The MMEs have variable SiO2 contents (45.7–60.2 wt%) and are more mafic than the host granitoids, but have similar Sr–Nd–Hf isotopic compositions to the host granitoids [(87Sr/86Sr)i = 0.7102–0.7110; εNd(t) = −6.57 to −3.56; εHf(t) = −7.17 to −1.81]. The MMEs are fragments of cumulates formed during the early stages of magma evolution. The granitoids were produced by the partial melting of a mélange source. The new data support the view that the Middle–Late Ordovician syn-collisional granitoids with MMEs distributed along the WKOB represent a magmatic response to terrane collision. This suggests that juvenile crustal growth in older orogenic systems, which occurs by arc addition, also involves some vertical addition during the final stage of orogenic collision. Our study suggests that mélange diaper melting is a key mechanism of crustal growth during the syn-collision stage in continental collision zones, associated with slab breakoff.

Investigating soil properties and their effects on freeze-thaw processes in a thermokarst lake region of Qinghai-Tibet Plateau, China

Soil parameters form the foundation of hydrogeological research and are crucial for studying engineering construction and maintenance, climate change, and ecological environment effects in cold regions. However, the soil properties in the permafrost region of the Qinghai–Tibet Plateau (QTP) remain unclear. Hence, in this study, soil temperature (Ts), volumetric specific heat capacity (C), thermal conductivity (K), thermal diffusivity (D), soil water content (SWC), electric conductivity (EC), vertical (Kv) and horizontal (Kh) saturated hydraulic conductivity, bulk density (ρb), and soil texture near the Qinghai-Tibet Railway were measured, and their effects on the freeze-thaw process were evaluated. The results revealed a predominantly sandy loam soil texture, with Kh and Kv showing strong spatial variability, while the other parameters presented moderate spatial variability. Thermokarst lake had a limited influence on D, C, K, and ρb but significantly reduced Kh and Kv. Groundwater affected SWC, Ts, and EC. The model results showed that all parameters indicated small sensitivities to the maximum thawing depth (MTD), with MTD positively responding to all parameters except for Kv and porosity (ρp). Except for Kh and Kv, all parameters showed high sensitivities to the time from starting to complete freezing (TSCF). TSCF responded positively to C, ρp, and density (ρd) and negatively to K and Kh. This study expanded the quantification of soil properties in the QTP, which can help improve the accuracy of cryohydrogeologic models, thus guiding the construction and maintenance of infrastructure engineering.

Differences in archaeal diversity and potential ecological functions between saline and hypersaline lakes on Qinghai-Tibet Plateau were driven by multiple environmental and non-environmental factors beyond the salinity

BackgroundSaline lakes are home to various archaea that play special and crucial roles in the global biogeochemical cycle. The Qinghai-Tibet Plateau hosts a large number of lakes with diverse salinity ranging from 0.1 to over 400 g/L, harboring complex and diverse archaea. To the best of our knowledge, the formation mechanisms and potential ecological roles of archaea in Qinghai-Tibetan Plateau saline lakes remain largely unknown.ResultsUsing High-throughput Illumina sequencing, we uncovered the vastly distinct archaea communities between two typical saline lakes with significant salinity differences on the Qinghai Tibet Plateau (Qinghai saline lake and Chaka hypersaline lake) and suggested archaea played different important roles in methanogenesis-related and nitrate reduction-related functions of these two lakes, respectively. Rather than the individual effect of salinity, the composite effect of salinity with diverse environmental parameters (e.g., temperature, chlorophyll a, total nitrogen, and total phosphorus) dominated the explanation of the variations in archaeal community structure in different habitats. Based on the network analysis, we further found the correlations between dominant archaeal OTUs were tight but significantly different between the two habitats, implying that archaeal interactions may also largely determine the shape of archaeal communities.ConclusionThe present study improved our understanding of the structure and function of archaea in different saline lakes on the Qinghai-Tibet Plateau and provided a new perspective on the mechanisms underlying shaping their communities.

Reevaluating Earthquake Fatalities in the Taiwan Region: Toward More Accurate Assessments

Abstract Earthquakes occurring in the Taiwan region have the potential to cause significant damage and loss of life. To ensure an effective emergence response and mitigate the impact of seismic events, it is imperative to develop an earthquake fatality prediction model that incorporates the Taiwan region’s seismic background, geological context, and socioeconomic level. This research article analyzes 35 historically damaging earthquakes in the Taiwan region, considering their fatality records, macroseismic intensities (modified Mercalli shaking intensity scale), and population exposure, to propose a specific seismic fatality ratio applicable to the Taiwan region. The model incorporates adjustments based on the gross national income per capita to address temporal and spatial disparities resulting from socioeconomic development. The predicted results highlight the superior performance of this fatality estimation model compared to other existing models. Furthermore, the earthquake fatality estimation model for the Taiwan region differs significantly from the models employed for South China and Qinghai–Tibet, suggesting variations in geological background, earthquake-resistant structures, and seismic resilience of society between the Taiwan region and mainland China. Moreover, a comparison with the U.S. Geological Survey model for the Taiwan region reveals that previous evaluations of the Taiwan region earthquakes greatly underestimated the number of fatalities.

Origin of the Dashuigou independent tellurium deposit at Qinghai–Xizang Plateau: constraints from the light stable isotopes C, O, and H

Origin of the Dashuigou independent tellurium deposit at Qinghai–Xizang Plateau: constraints from the light stable isotopes C, O, and H

Evaluation of ERA5, ERA5-Land, GLDAS-2.1, and GLEAM potential evapotranspiration data over mainland China

Study regionChina. Study focusAccurate estimation of potential evapotranspiration (PET) is essential for understanding climate change. Using ground-based pan evaporation measurements over continental China, the monthly scale PET data during 2000–2017 of ERA5, ERA5-Land, GLDAS-2.1/Noah, and GLEAM V3.8a are evaluated, from the perspectives of their consistency in spatiotemporal variation, and performance measures. Factors controlling the data quality of the four datasets are investigated from the perspective of their PET calculation models and meteorologically input data. New hydrological insights for the regionPETERA5 performs the best in mainland China among four gridded PET datasets with higher correlation coefficients (r) and smaller biases, which can well capture the temporal variation of Epan. The outstanding performance of PETERA5 in China mainly results from the utilization of the Penman-Monteith (P-M) equation which performs the best among several competing formulas for PET computation, as well as its better meteorological inputs for computing PET than other datasets. Although the PETERA5-Land is a replay of the land component of the ERA5 climate reanalysis, it exhibits substantial overestimation of PET values and temporal trends, particularly in coastal areas of Southern China and the eastern side of Northeastern China, mainly caused by the overestimation of its net radiation. The PETGLDAS shows significant overestimation, partly due to its overestimation of wind speed, but mostly due to its modified P-M equation with its parameterization of land surface conditions for computing PETGLDAS. The PETGLEAM underestimated PET generally mainly due to the joint effect of the use of the Priestley-Taylor equation with small P-T parameter α, and the underestimation of the net radiation input from ERA-Interim, especially in Northwest and Qinghai Tibet.

Protection Gains and Potential Risks: Insights from a Decade of Change of Chiru in the Arjinshan

As a migratory ungulate species, the chiru ( Pantholops hodgsonii ) primarily inhabits the Qinghai–Xizang Plateau. The population of the chiru has experienced a steady increase in recent years due to the implementation of rigorous conservation measures, including the establishment of nature reserves and legislation prohibiting hunting and killing. However, the study of chiru population ecology remains poorly understood duo to the unique and harsh natural conditions, as well as the seasonal migration and breeding patterns. In our study, we observed a higher overall population of the chiru (with average daily observations of 352 in 2012–2013 and 453 in 2023) and a demographic shift toward younger age groups (with juvenile percentage at 17.23% in 2023 and 15.85% in 2012–2013), implying the effectiveness of conservation efforts. But the marked increase in mortality rates among chiru warrants serious attention, particularly with regard to juvenile fatalities (from 1 death in 2012–2013 to 51 deaths in 2023). During past conservation efforts, the chiru population has gradually recovered; however, it is imperative to acknowledge the potential future risks due to accelerated climate change and intensification of human activity.

Emergence of Lumpy Skin Disease Virus Infection in Yaks, Cattle‐Yaks, and Cattle on the Qinghai–Xizang Plateau of China

Lumpy skin disease (LSD) is a viral disease caused by lumpy skin disease virus (LSDV), which mainly infects cattle and can cause huge economic losses. In May 2023, yaks, cattle‐yaks, and cattle in Tibet (Xizang), China, developed fever, skin nodules, and severe discharges and were suspected to be cases of LSD. Samples from these animals were analyzed using molecular biology and serological methods. The RPO30, P32, and GPCR genes were amplified by PCR and sequenced, and the whole genome of the virus was determined using viral metagenomics technology. Sequencing results showed that it was indeed an LSDV infection, and enzyme‐linked immunosorbent assay results confirmed the presence of LSDV antibodies. The whole genome phylogenetic tree shows that LSDV/CHINA/Tibet/2023 is different from the previous epidemic strains in China, but clusters with India 2022 strain. This is the first report of LSD in yaks, cattle‐yaks, and cattle on the highest altitude plateau in the world.

Reclamation Enhances the Ratio of Soil to Ecosystem Respiration under Warming in an Alpine Meadow

The construction of cultivated grasslands can increase grass production but also pose a threat to soil carbon storage, and it still remains unclear how construction of cultivated grasslands affects the components of ecosystem respiration (ER) toward a warming climate. Therefore, we conducted a 5-year (2012 to 2016) manipulative warming experiment in an alpine meadow and a cultivated grassland on the Qinghai–Xizang Plateau to explore the separate and interactive effects of warming and reclamation on soil respiration (SR), crop respiration (CR), ER, and the ratio of SR to ER (SR/ER). The plant height, coverage, aboveground production, SR, ER, CR, and SR/ER were measured. We found that warming increased the 5-year mean SR by 61.1% and 63.4% in the alpine meadow and the cultivated grassland, respectively. The 5-year mean SR/ER was increased by warming for the alpine meadow (38.7%) and the cultivated grassland (38.0%). Under warming, reclamation increased the 5-year mean SR/ER by 15.0%. Reclamation increased the sensitivity of SR and CR to warming, resulting in the increase in SR/ER under warming in the cultivated grassland. Overall, our results indicated that reclamation can increase the contribution of SR to the ecosystem carbon emission under warming and is detrimental to the storage of soil carbon in the alpine meadow especially toward a warming climate. Therefore, despite the increase in production by the construction of cultivated grasslands, the increase in carbon emission under warming by reclamation should attract attention.

Distribution Patterns of Gymnosperm Species along Elevations on the Qinghai–Tibet Plateau: Effects of Climatic Seasonality, Energy–Water, and Physical Tolerance Variables

Climate change is one of the most prominent factors influencing the spatial distribution of plants in China, including gymnosperms. Climatic factors influence gymnosperm distribution along elevational gradients on the Qinghai–Xizang (Tibet) Plateau (QTP), and understanding how species adapt to these factors is important for identifying the impacts of global climate change. For the first time, we examined the county-level distribution of gymnosperm species on QTP using data from field surveys, published works, monographs, and internet sources. We used simulated distribution data of gymnosperms (N = 79) along the elevational gradients to investigate the overall impact of environmental variables in explaining the richness pattern of gymnosperms. Eighteen environmental variables were classified into three key variable sets (climatic seasonality, energy–water, and physical tolerance). We employed principal component analysis and generalized linear models to assess the impact of climatic variables on the gymnosperm’s richness pattern. Gymnosperm species are unevenly distributed across the plateau and decline gradually from the southeast to the northwest. The altitudinal gradients have a unimodal relationship with the richness of gymnosperms, with the maximum species richness at an elevation of 3200 m. The joint effects of physical tolerance and energy–water predictors have explained the highest diversity of gymnosperms at mid-elevation. Because the richness peak correlates significantly with the wettest month’s precipitation and moisture index, this confirms the significance of moisture on gymnosperm distributions due to increased precipitation during the wet season. Furthermore, our results provide evidence that climatic seasonality factors are involved in the decline of gymnosperm richness at high elevations. A total of 37% of gymnosperm species on QTP are listed as vulnerable, nearly threatened, or endangered, with elevations ranging from 600 m to 5300 m. As a result, we conclude that gymnosperms are at high risk of extinction because of the current climate fluctuations caused by global climate change. Our research offers fundamental data for the study and protection of gymnosperm species along the steepest elevation gradients.

Just Transition in Response to Climate Change: A Case Study of Trans-Altitude Migrant Resettlement on the Qinghai–Xizang Plateau

As a measure toward a joint target of promoting residents’ life, combating climate change, and protecting ecosystem in the Qinghai–Xizang Plateau, migrant resettlement has made a remarkable achievement not only in preserving the ecological environment and building climate barriers, but also in significantly upgrading the residents’ life quality. Yet, it also faces a multitude of challenges, such as the issue of just transition, which concerns the international community. To promote a just transition, the primary challenge lies in addressing the imbalance between the supply and demand in the resettlement. This includes matching the supply of public services with the material needs related to production and residents’ life, as well as the alignment between the residents’ cultural and psychological identification and the grassroots services available. Using Maslow’s hierarchy of needs as a theoretical framework, this paper examines just transition in migrant resettlement on the Qinghai–Xizang Plateau from a supply–demand perspective based on follow-up fieldwork, and argues that the local community has achieved significant progress in promoting just transition in terms of material security, spiritual needs, and self-development, but further efforts should still be made to improve just transition and ensure a more sustainable future.

Determine the Optimal Vegetation Type for Soil Wind Erosion Prevention and Control in the Alpine Sandy Land of the Gonghe Basin on the Qinghai Tibet Plateau

There is a dearth of research regarding the windbreak and sand stabilization functions of Caragana liouana shelter forests in the Gonghe Basin of the Qinghai-Tibet Plateau. Therefore, the aim is to elucidate the patterns of near-surface wind–sand activity in artificial Caragana liouana forests of varying ages and mixed forests of different configurations in alpine sandy areas. Additionally, this research seeks to clarify the windbreak and sand fixation effects of these forests. To this end, we have selected artificial forests of Caragana liouana of varying ages (10-year-old pure Caragana liouana forest (10aZJ-C), 17-year-old pure Caragana liouana forest (17aZJ-C), 37-year-old pure Caragana liouana forest (3aZJ-C)) and shrub mixed forests of different mixing modes (10-year-old Caragana liouana and Caragana korshinskii mixed forest (10aNZ-HJ), 10-year-old Caragana liouana and Artemisia desertorum mixed forest (10aSZ-HJ), an 10-year-old Caragana liouana and Salix cheilophila mixed forest (10aWZ-HJ)) within the Sand Control Station of Shazhuyu Village in the Gonghe Basin of the Qinghai-Tibet Plateau as the research subjects. Naked sand dunes were used as the control plot (CK), and through field observations of the wind speed profile, sand transport rate, and micro-topographic changes of each stand plot, we analyzed the wind–sand flow structure characteristics and sand transport process of Caragana liouana of different ages and their mixed forests, eventually proposing suitable afforestation configuration modes for the alpine sand area of the Gonghe Basin in Qinghai. The findings indicate that the wind speed profile within each stand plot follows a linear distribution pattern. Compared to naked dune land, the windbreak effect of each plot decreases as the height from the ground increases. Among them, the 10aWZ-HJ plot significantly alters the wind speed profile and has a substantial windbreak effect; at a height of 200 cm, the windbreak effect can still reach 41.27%. The sand transport rate of each plot fits into an exponential function relationship, with the correlation coefficients (R2) of the fitting equations for each plot all exceeding 0.95 and significantly lower than the control plot, suggesting vegetation can effectively reduce near-surface sand transport. The sand-fixing effects at the height of 0–45 cm from the ground in each plot are as follows: 37aZJ-C > 17aZJ-C > 10aWZ-HJ > 10aNZ-HJ > 10aZJ-C > 10aSZ-HJ. Overall, all plots indicate a state of accumulation. The 10aWZ-HJ plot has the largest relative accumulation area at 88.00%, and the highest average intensity of wind erosion and accumulation at 1.11. Taking into account the stability of the stand and the total protection time, this study suggests that it is suitable to mainly use mixed forests of Salix cheilophila and Caragana liouana in the alpine sand area of the Qinghai-Tibet Plateau. The results of this study can provide a theoretical basis for the construction of windbreak and sand-fixing forests in alpine sand areas.

Heterogeneity and Spatial Governance of Synergy between Human Activities and Ecological Conservation in the Qinghai–Xizang Plateau, China

The Qinghai–Xizang Plateau is one of the important units of the major project of ecosystem protection and restoration in China’s “three zones and four belts”(2021–2035), and balancing its ecological security with rational regional development is the basis for ensuring China’s ecological stability. In this paper, the coupling mechanism between regional development intensity and ecological security is explained, and a measurement system of the relationship is designed, from which the coordination degree and type division of the coupling between regional development intensity and ecological security on the Qinghai–Xizang Plateau from 2011 to 2020 is measured. The results show the following: (1) During the study period, the regional development intensity of the Qinghai–Xizang Plateau has been increasing, with Xining and Lhasa as the “core” that drives the development and expansion of the surrounding areas. The ecological security index has been also on the rise, showing a pattern of “belt-shaped depressions in the central and western parts of the Plateau, and vertical clusters in the eastern part of the Plateau”. The depression moves toward the southern part of Xinjiang. (2) The degree of coupling and coordination between development intensity and ecological safety in each city (prefecture) on the Qinghai–Xizang Plateau has increased by different degrees, but many cities (prefectures) still show a lag in development intensity or ecological security. (3) The evolution of the pattern of coupling and coordination between regional development intensity and ecological security on the Qinghai–Xizang Plateau varies significantly, forming a pattern of “high in the east and low in the west, with multiple clusters side by side”. To some extent, this paper reveals the correlation between the spatial and temporal distributions of regional development intensity and ecological security on the Qinghai–Xizang Plateau, which can provide a basis for the regulation of human activities in the construction of ecological security barriers at the city (prefecture) level on the Qinghai–Xizang Plateau.

Spatial Risk Assessment of the Effects of Obstacle Factors on Areas at High Risk of Geological Disasters in the Hengduan Mountains, China

The Hengduan Mountains in China are known for their complex geological environment, which leads to frequent geological disasters that pose significant threats to the safety and economic and social development of the local population. In this study, we developed develop a multi-dimensional evaluation index system from the aspects of economy, society, ecology, and infrastructure, and the resilience inference measurement (RIM) model was developed to assess resilience to regional disasters. The clustering evaluation of exposure, damage, and recovery variables in four states was conducted by way of K-means clustering. The results of K-means clustering are confirmed by discriminant analysis, and the disaster resilience index was empirically verified once. At the same time, the obstacle factor was further analyzed with the obstacle degree model. The results indicate that there are 8 susceptible areas, 23 recovering areas, 27 resistant areas, and 7 usurper areas. The classification accuracy of the model is 95.4%. The disaster resilience of high-risk areas was found to be low, with “extremely poor” differentiation, where the majority of the areas had low resilience and only a minority had high resilience. A “high in the southeast and low in the northwest” spatial distribution was observed. High-resilience areas were “dotted” and mainly concentrated in core areas with a high population density and strong economic activity, while low-resilience areas had a pattern of “edge extension” and were mainly distributed in the transition zone between the Qinghai–Tibet and Yunnan Plateaus. There were clear differences in the barriers of disaster resilience among the 65 counties (cities). The economic barrier degree was found to be the largest barrier to disaster resilience, followed by ecological, social, and infrastructure barrier degrees. The main factors affecting the distribution of disaster resilience in the high-risk areas were topographic relief, proportion of female population, cultivated land area, industrial structure, number of industrial enterprises above a designated size, and drainage pipeline density in the built-up area. Additionally, primary barrier factors classify the 65 counties (cities) into three types: economic constraint, natural environment constraint, and population structure constraint.

Effects of formal credit on pastoral household expense: Evidence from the Qinghai–Xizang Plateau of China

Formal credit is critical in agricultural production, allowing more expenditure and productive input, thereby improving farmers’ welfare. In pastoral China, formal financial institutions are gradually increasing. However, a limited understanding remains of how formal credit affects herders’ household expenses. Based on a survey of 544 herders from the Qinghai–Xizang Plateau of China, this study adopted the propensity score matching approach to identify the effect of formal credit on herders’ total household expenses, daily expenses, and productive expenses. The results found that average age, grassland mortgage, and other variables significantly affected herders’ participation in formal credit. Formal credit could significantly improve household expenses, especially productive expenses. A heterogeneity analysis showed that formal credit had a greater impact on the household total expense for those at higher levels of wealth; however, it significantly affected the productive expense of herders at lower wealth levels. Moreover, the mediating effect indicated that formal credit could affect herders’ household income, thus influencing their household expenses. Finally, this study suggests that policies should improve herders’ accessibility to formal credit.

Geodynamics of progressive growth of arcuate fold-and-thrust belts: Insights from numerical modeling of the NE margin of the Qinghai-Tibetan plateau

As the front of the northeastward-growth region of the Qinghai-Tibetan Plateau since the Cenozoic, arcuate fold-and-thrust belts are the main features of local tectonic deformation. However, the formation mechanism of these arcuate structures is still an open question. We present 3D finite-element models with elasto-plastic rheology to understand the formation-evolution of arcuate folds here comprising real regional fault-zones including the Haiyuan, Xiang Shan–Tianjing Shan, Yantong Shan, and Niushou Shan faults since ∼10 Ma. The reference-model equivalent-plastic-strain (EPS) concentration zones develop outwardly-NE in spatio-temporal sequence, with development geometry and timing in good agreement with the geologic fault-zone structures. Our reference-model-based sensitivity analysis suggest that the horizontal northeastward compression of the region being bounded by a frictional vicinity (rigid Alxa and Ordos blocks hindering the advancement) have the dominant control on the formation and evolution of these arcuate fold-and-thrust belts perpendicular to the contraction axis. In contrast, the likely-small rotations imprinted by the Ordos and Alxa blocks and the minor shearing of the Qinghai–Tibetan Plateau, have only secondary effects. An additional, generic sensitivity analysis reveals that the folds’ horizontal curvature per unit horizontal shortening-displacement increases with the friction on the bounding vicinity, and this result could be considered for other scenarios of Earth and other planets. Historical regional earthquakes of M > 6 are mostly located in the simulated EPS concentration zones: the 1920 Haiyuan and 1709 Zhongwei earthquakes occurred on the Haiyuan and Xiang Shan–Tianjing Shan faults, respectively, well correlated with our model high-EPS concentration zones.

Satellite evidence for small biophysical effects of transport infrastructure in the Qinghai-Tibet Plateau

Transport expansion is detrimental to natural ecosystems and yet to what extent it can impact nearby alpine ecosystems is not well understood. This case study in Qinghai–Tibet railway and highway explores the biophysical effects of transport infrastructure in terms of remote sensing-based greenness, wetness, dryness, and heat according to a space-for-time substitution method. We estimate highly diverse changes across road sections in all the indices from both multiyear-mean and long-term perspectives, and no clear biophysical gradients with distance away from the transport lines, except for a gradual decrease in multiyear-mean heat and wetness. In a 500-m buffer zone, those indices on average are 0.1–15.7% lower or higher than the references and the disparities increase or decrease significantly from 2000 to 2021 alongside 15–48% of the transport lines. We further find that the estimated biophysical changes depend strongly on the reference conditions and the elevation gradients nearby the roads. Also, the road sections surrounded by some urban/crop lands show much more frequent “significant” trends than the others, confirming strong land use effects on the biophysical dynamics in alpine regions. Nevertheless, it remains open to debate to what extent transportation contribute the land use activities near the roads. We argue that highways and railways unlikely strongly impact the biophysical conditions in alpine regions due to small road width, widespread nature reserves, various protective measures, and low accessibility to surroundings if they are fenced. Our results highlight the small biophysical impacts of transport infrastructure on roadside natural ecosystems in the Qinghai-Tibet Plateau and suggest prioritized attention to the direct damages to soil and vegetation by transport construction and the habitat disruption, biodiversity change, and road kills by transport operation for developing an environment-friendly transport system.

Regional distribution and migration potential of antibiotic resistance genes in croplands of Qinghai Tibet Plateau

Agricultural activities have recently disturbed the ecosystem of the Qinghai-Tibet Plateau and the shift of antibiotic resistance genes (ARGs) in the different types of farmlands is not well understood, so more comprehensive ecological barrier management measures cannot be provided for the region. This research was performed to exploring ARG pollution in cropland soil on the Qinghai-Tibet Plateau to obtain information on the geographical and climatic factors shaping the ARG distribution. Based on high-throughput quantitative PCR (HT-qPCR) analysis, the ARG abundance in farmland ranged from 5.66 × 105 to 6.22 × 107 copies per gram of soil higher than previous research at soil and wetland in Qinghai-Tibet plateau, and it was higher in wheat and barley soils than in corn soil. The distribution of ARGs exhibited regional features as ARG abundance was adversely affected by mean annual precipitation and temperature with lower temperature and less rainfall at high altitude. According to network analysis and structural equation modeling (SEM), mobile genetic elements (MGEs) and heavy metals are the key drivers of ARG dissemination on the Qinghai-Tibet Plateau as they show negative relationship with ARGs, and selection copressure from heavy metals in cropland soil increases the horizontal gene transfer (HGT) potential of ARGs through synergistic selection effects, each contribution to the ARGs was 19% and 29% respectively. This research suggests the need to focus on controlling heavy metals and MGEs to constrain the dissemination of ARGs, as arable soil is already slightly contaminated by heavy metals.