Quantitative assessment of the impact of climatic factors on phenological changes in the Qilian Mountains, China

2021 ◽  
Vol 499 ◽  
pp. 119594
Author(s):  
Yunfan Sun ◽  
Qingyu Guan ◽  
Qingzheng Wang ◽  
Liqin Yang ◽  
Ninghui Pan ◽  
...  
2021 ◽  
Vol 13 (12) ◽  
pp. 2400
Author(s):  
Quntao Duan ◽  
Lihui Luo ◽  
Wenzhi Zhao ◽  
Yanli Zhuang ◽  
Fang Liu

Human activities have dramatically changed ecosystems. As an irreplaceable ecological barrier in western China, the Qilian Mountains (QLM) provide various ecosystem services for humans. To evaluate the changes in the intensity of human activities in the QLM and their impact on the ecosystem, the human footprint (HF) method was used to conduct a spatial dataset of human activity intensity. In our study, the NDVI was used to characterize the growth of vegetation, and six categories of human pressures were employed to create the HF map in the QLM for 2000–2015 at a 1-km scale. The results showed that the mean NDVI during the growing season showed a significant increasing trend over the entire QLM in the period 2000–2015, while the NDVI showed a significant declining trend of more than 70% concentrated in Qinghai. Human pressure throughout the QLM occurred at a low level during 2000–2015, being greater in the eastern region than the western region, while the Qinghai area had greater human pressure than the Gansu area. Due to the improvement in traffic facilities, tourism, overgrazing, and other illegal activities, grasslands, shrublands, forests, wetlands, and bare land were the vegetation types most affected by human activities (in decreasing order). As the core area of the QLM, the Qilian Mountains National Nature Reserve (NR) has effectively reduced the impact of human activities. However, due to the existence of many ecological historical debts caused by unreasonable management in the past, the national park established in 2017 is facing great challenges to achieve its goals. These data and results will provide reference and guidance for future protection and restoration of the QLM ecosystem.


Geophysics ◽  
2019 ◽  
Vol 84 (4) ◽  
pp. B247-B258 ◽  
Author(s):  
Bo Yang ◽  
Xiangyun Hu ◽  
Wule Lin ◽  
Shuang Liu ◽  
Hui Fang

In China, gas hydrates in onshore permafrost areas have so far only been found in the Juhugeng Mine of the Qilian Mountains. However, their subsurface distribution remains unclear. Electrical resistivity logs have revealed that zones containing gas hydrates have higher resistivity than surrounding zones, which makes electromagnetic methods viable for detecting gas-hydrate deposits. We have deployed a natural-source audio-magnetotelluric (AMT) survey at the Juhugeng Mine. AMT data were collected at 176 sites along five profiles, and resistivity models were derived from 2D inversions after detailed data analysis. After the available geologic and geophysical observations were combined, the inversion results from profile 1 suggested that permafrost near the surface with high resistivity and thickness is essential for underlying gas hydrates to be present. The decrease in resistivity and/or thickness of permafrost due to climate change may lead to gas-hydrate dissociation. The other four AMT transects suggested three prospective gas-hydrate sites. Our results indicate that the AMT survey technique is suitable for exploring gas hydrates in permafrost areas and analyzing the impact of permafrost characteristics on gas-hydrate occurrence.


Water ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1797 ◽  
Author(s):  
Jianqiao He ◽  
Wei Zhang ◽  
Yuwei Wu

The precipitation δ18O-elevation gradients are important for paleoclimate, hydrology, and paleoelevation studies. The field setting for this research was the upper reaches of the Heihe River Basin within the Qilian Mountains in the Northern Tibetan Plateau. Three study sites were established along the Heihe main river. These sites were the Yingluoxia and Qilian hydrological stations and the Yeniugou meteorological station. The Yingluoxia hydrological station was the dividing point between the upper and middle reaches of the Heihe River Basin. The altitudes of these sites range from 1600 m to 3300 m. Summer precipitation is predominant with regard to the annual precipitation amount. By analysis of variance (ANOVA), the precipitation δ18O data collected from the three sites were analyzed, spanning a year of precipitation data from 2007.10 to 2008.9. The results showed that the δ18O-elevation gradient was not significant (α = 0.05) at a seasonal or annual scale in this region and the precipitation-weighted annual mean δ18O was −7.1‰. Mechanisms that have been proposed to explain this result consider the role of two processes, including (1) mixing of moisture sources, a process common in an arid and semiarid region, and (2) the absence of a mechanism for water vapor to climb along slopes in the precipitation system. Atmospheric water vapor mainly travels along the trend of the Qilian Mountains range rather than climbing it because this region is dominated by the westerlies and the trend of the Qilian mountains is geographically aligned to the NWW (north-west-west) direction. We demonstrated that, aside from the water vapor source, the spatial relationship between the water vapor transport pathway and the trend of the mountain range are the main driving factors associated with the stable isotope trends in precipitation. As a result, it is important to re-recognize the timing and location of groundwater recharge in the Heihe River Basin.


2019 ◽  
Vol 136 ◽  
pp. 04014
Author(s):  
Lei Feng ◽  
Dong Yang ◽  
Yueyue Huang

The impact of climate change on the basin is extensive and long-lasting, which will have a profound impact on the natural ecosystems, water resources, agriculture, and human production and life throughout the basin. An in-depth understanding of the impacts of climate change on watersheds and quantitative assessments will help to scientifically plan and manage water resources and protect the integrity of natural ecosystems. In this paper, temperature, precipitation and potential evapotranspiration data were used to analyze the response of Xiying River runoff to climatic factors in the Qilian Mountains by sliding correlation and wavelet analysis. M-K test and cumulative anomaly (CA) were used to analyze the climatic factors and runoff in the basin and use the pettitt method to test. Finally, the cumulative rate slope change rate comparison method was used to analyze the change of precipitation, potential evapotranspiration and snow-melt water contribution to runoff in this area. The results showed that temperature, precipitation and potential evapotranspiration had obvious mutations from 1961 to 2012 in this region. Compared with temperature and potential evapotranspiration, the precipitation showed greater impact on runoff. In addition, the contribution rate of ice and snow melt water to runoff was relatively larger in 1990 - 2002 compared to 1961-1989, followed by precipitation and evapotranspiration; the increase of the precipitation contribution rate became the main factor to runoff, followed by ice and snow melting and evapotranspiration compared to 1990-2002 in 2003-2017.


2021 ◽  
Vol 13 (23) ◽  
pp. 12943
Author(s):  
Zhuanxia Zhang ◽  
Guofeng Zhu ◽  
Hanxiong Pan ◽  
Zhigang Sun ◽  
Liyuan Sang ◽  
...  

Studies about the hydrological cycle based on basin or regional scales often ignore the uniqueness of recycling moisture in mountain areas, and little effort has been made to understand the impact of the local recycled moisture on precipitation in mountain areas. We collected and analyzed a series of samples (stable isotope of precipitation, soil water, plant water, runoff, and groundwater) in the Qilian Mountains, northwest of China. Based on the isotopic mixing model, the characteristics of recycled moisture in the Qilian Mountains were evaluated. The results showed that lateral advection moisture is the primary source of precipitation (83.5~98.38%). The contribution rate of recycled moisture to precipitation was higher in the spring, summer, and autumn (2.05~16.5%), and lower in the winter (1.62~3.32%). The contribution of recycled moisture to precipitation in the high-elevation areas (>2400 m) was higher than that in the foothills area (2100~2400 m). The contribution of vegetation transpiration (fTr) to precipitation in the east of Qilian Mountain was higher than that of the land surface evaporation (fEv). These proved that in the eastern part of Qilian Mountain, the arge-scale water cycle has a greater impact on precipitation in the area. The influence of local circulating water on precipitation dominated in the summer half of the year. Understanding the contribution of local circulating water to precipitation in the eastern part of Qilian Mountain will help us to understand the local hydrothermal conditions better and provide a basis for rationally arranging local agricultural production activities.


CATENA ◽  
2022 ◽  
Vol 208 ◽  
pp. 105694
Author(s):  
Yunrui Ma ◽  
Qingyu Guan ◽  
Yunfan Sun ◽  
Jun Zhang ◽  
Liqin Yang ◽  
...  

Author(s):  
Yanni Zhao ◽  
Rensheng Chen ◽  
Chuntan Han ◽  
Lei Wang ◽  
Shuhai Guo ◽  
...  

AbstractA precipitation observation network was constructed in a high-altitude area of the Qilian Mountains in Northwest China, which contained 23 sets of instruments. Because 21 sets of instruments were surrounded by protective fences, a precipitation intercomparison experiment was carried out at the highest station (4651 m) of the observation network with the same configuration to study the impact of wind on precipitation measurements under this configuration and to develop a correction method suitable for the entire network. The 30-min measured precipitation from June 2018 to October 2019 was corrected by transfer functions provided by Kochendorfer et al. (2017b), and their parameters were recalibrated with a local dataset. The results showed that the transfer functions fitted to the local dataset had a better performance than those using original parameters. Because of the influence of the experimental configuration on wind speed and direction, the root mean square error (RMSE) corrected with the original parameters increased by an average of 86%, but the RMSE adjusted by the new transfer functions decreased by 9%. Moreover, the resultant biases using new transfer functions were close to 0. The new coefficients of snowfall were derived by local measurements and applied to datasets from other sites within the Qilian Mountains observation network to evaluate their performances. The corrected snowfall at 21 stations increased by an average of 32.6 mm, and the relative precipitation increment ranged from 6% to 26%. This method can be used to correct snowfall in the observation network under the non-standard site configuration.


Author(s):  
S. A. Gorbanev ◽  
S. A. Syurin ◽  
N. M. Frolova

Introduction. Due to the impact of adverse working conditions and climate, workers in coal-mining enterprises in the Arctic are at increased risk of occupational diseases (OD).The aim of the study was to study the working conditions, causes, structure and prevalence of occupational diseases in miners of coal mines in the Arctic.Materials and methods. Th e data of social and hygienic monitoring “Working conditions and occupational morbidity” of the population of Vorkuta and Chukotka Autonomous District in 2007–2017 are studied.Results. It was established that in 2007–2017 years, 2,296 ODs were diagnosed for the first time in 1851 coal mines, mainly in the drifters, clearing face miners, repairmen and machinists of mining excavating machines. Most often, the ODs occurred when exposed to the severity of labor, fibrogenic aerosols and hand-arm vibration. The development of professional pathology in 98% of cases was due to design flaws of machines and mechanisms, as well as imperfections of workplaces and technological processes. Diseases of the musculoskeletal system (36.2%), respiratory organs (28.9%) and nervous system (22.5%) prevailed in the structure of professional pathology of miners of coal mines. Among the three most common nosological forms of OD were radiculopathy (32.1%), chronic bronchitis (27.7%) and mono-polyneuropathy (15.4%). In 2017, coal miners in the Arctic had a professional morbidity rate of 2.82 times higher than the national rates for coal mining.Conclusions. To preserve the health of miners of coal mining enterprises, technical measures to improve working conditions and medical interventions aimed at increasing the body’s resistance to the effects of harmful production and climatic factors are necessary.


Author(s):  
Nina M. Meshchakova ◽  
Marina P. Dyakovich ◽  
Salim F. Shayakhmetov

Introduction.Methanol and its derivatives occupy one of the leading places among the main organic synthesis intermediates in terms of their importance and scale of production. According to experts, by 2027 the global demand for methanol can reach 135 million tons, the annual growth will be about 5.5%. However, there is little information regarding the assessment of working conditions and occupational risks for workers in modern methanol production and its derivatives.The aim of the studyis hygienic assessment of working conditions and the formation of health risks in workers of modern production of methanol and methylamines.Materials and methods.The assessment of the main adverse factors of production is given. When studying the state of health, objective indicators (the results of an in-depth medical examination) and subjective (the results of a quantitative assessment of the risks of the main pathological syndromes associated with health) are considered.Results.According to long-term observations, the concentration of harmful substances in the air of the working area, indicators of labor severity, parameters of physical factors met hygienic requirements, with the exception of industrial noise exceeding the maximum permissible level, as well as labor intensity of 1 degree. The General assessment of working conditions corresponds to the category of harmful 2 degrees (3.2). According to the results of the medical examination and quantitative assessment of the risks of health disorders in workers, the most significant were functional disorders and diseases of the circulatory system. The levels of somatic pathology on the part of the main body systems were significantly higher in apparatchiks compared to the engineering and technical personnel (ETP).Conclusions:In the production of methyl alcohol and methylamines, the main hygienic importance is the impact on workers of the complex of harmful substances of 1-IV hazard classes in low concentrations, increased levels of industrial noise, labor intensity of 1 degree. According to the subjective assessment of health and medical examination, the greatest prevalence of health risks in workers was observed from the circulatory system, and the levels of the revealed somatic pathology were statistically significantly higher in apparatchiks compared with the ETP.


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