检索结果-南通市图书馆

Characteristics of air pollution events over Hotan Prefecture at the southwestern edge of taklimakan desert, China

在线全文

学校读者我要写书评

暂无评论

Journal of Arid Land 2018年第5期10卷 686-700页

作者： LI Jingxin WANG Shigong CHU Jinhua WANG Jiaxin LI Xu YUE Man SHANG Kezheng State Key Laboratory of Severe Weather Chinese Academy of Meteorological Sciences Beijing 100081 China Sichuan Key Laboratory of Plateau Atmosphere and Environment College of Atmospheric Sciences Chengdu University of Information Technology Chengdu 610225 China Gansu Key Laboratory of Arid Climate Change and Reducing Disaster College of Atmospheric Sciences Lanzhou University Lanzhou 730000 China Chongqing Meteorological Bureau Chongqing 401147 China

Hotan Prefecture is located at the southwestern edge of taklimakan desert, the world＇s largest shifting sand desert, of China. The desert is one of the main sources for frequent sand-dust weather events which strongly affect the air quality of Hotan Prefecture. Although this region is characterized by the highest annual mean PMlo concentration values that are routinely recorded by environmental monitoring stations across China, both this phenomenon and its underlying causes have not been adequately addressed in previous researches. Reliable pollutant PM_10 data are currently retrieved using a tapered element oscillating microbalance （TEOM） 1400a, a direct real-time monitor, while additional concentration values including for PM_2.5, sulfur dioxide （SO_2）, nitrogen dioxide （NO_2）, carbon monoxide （CO） and ozone （O_3） have been collected in recent years by the Hotan Environmental Monitoring Station. Based on these data, this paper presents a comparison of the influences of different kinds of sand-dust weather events on PM_10 （or PM_2.5） as well as the concentrations of other gaseous pollutants in Hotan Prefecture. It is revealed that the highest monthly average PM_10 concentrations are observed in the spring because of the frequent occurrence of three distinct kinds of sand-dust weather events at this time, including dust storms, blowing dust and floating dust. The floating dust makes the most significant contribution to PM_10 （or PM_2.5） concentration in this region, a result that differs from eastern Chinese cities where the heaviest PM_10 pollution occurs usually in winter and air pollution results from the excess emission of local anthropogenic pollutants. It is also shown that PM_10 concentration varies within wpical dust storms. PM_10 concentrations vary among 20 dust storm events within Hotan Prefecture, and the hourly mean concentrations tend to sharply increase initially then slowly decreasing over time. Data collected from cities in eastern China show the op

关键词： PM10 (or PM2.5) concentration sand-dust weather events gaseous pollutants air pollution taklimakan desert

Estimation of the Land Surface Emissivity in the Hinterland of taklimakan desert

在线全文

学校读者我要写书评

暂无评论

Journal of Mountain Science 2014年第6期11卷 1543-1551页

作者： LIU Yong-qiang Ali MAMTIMIN HUO Wen YANG Xing-hua LIU Xin-chun MENG Xian-yong HE Qing College of Resource & Environmental Sciences Xinjiang University Key Laboratory of Oasis Ecology (Ministry of Education) Key Laboratory of City Intellectualizing and Environment Modeling Xinjiang University Institute of desert Meteorology China Meteorological Administration desert Atmosphere & Environment Observation Experiment Station of taklimakan

An accurate accounting of land surface emissivity(ε) is important both for the retrieval of surface temperatures and the calculation of the longwave surface energy *** ε is one of the important parameterizations in land surface models(LSMs),accurate accounting also improves the accuracy of surface temperatures and sensible heat fluxes simulated by *** order to obtain an accurate emissivity,this paper focuses on estimating ε from data collected in the hinterland of taklimakan desert by two different *** the first method,ε was derived from the surface broadband emissivity in the 8–14 μm thermal infrared atmospheric window,which was determined from spectral radiances observed by field measurements using a portable Fourier transform infrared spectrometer,the mean ε being *** second method compared the observed and calculated heat fluxes under nearneutral atmospheric stability and estimated ε indirectly by minimizing the root-mean-square difference between *** result of the second method found a mean value of 0.9042,which is consistent with the result by the first *** the two methods recover ε from different field experiments and data,the difference of meanvalues is *** first method is superior to the indirect method,and is also more convenient.

关键词： taklimakan desert Land surface emissivity Thermal infrared spectra Surface temperature Heat flux

Improving the CoLM in taklimakan desert Hinterland with Accurate Key Parameters and an Appropriate Parameterization Scheme

在线全文

学校读者我要写书评

暂无评论

Advances in Atmospheric Sciences 2012年第2期29卷 381-390页

作者：刘永强何清张宏升艾力.买买提明 Institute of desert Meteorology China Meteorological Administration College of Resources & Environmental Science Xinjiang University Key Laboratory of Oasis Ecology (Xinjiang University) Ministry of Education desert Atmosphere and Environment Observation Experiment of taklimakan Station Department of Atmospheric Sciences Peking University

Improving and validating land surface models based on integrated observations in deserts is one of the challenges in land modeling. Particularly, key parameters and parameterization schemes in desert regions need to be evaluated in-situ to improve the models. In this study, we calibrated the land-surface key parameters and evaluated several formulations or schemes for thermal roughness length （z 0h ） in the common land model （CoLM）. Our parameter calibration and scheme evaluation were based on the observed data during a torrid summer （29 July to 11 September 2009） over the taklimakan desert hinterland. First, the importance of the key parameters in the experiment was evaluated based on their physics principles and the significance of these key parameters were further validated using sensitivity test. Second, difference schemes （or physics-based formulas） of z 0h were adopted to simulate the variations of energy-related variables （e.g., sensible heat flux and surface skin temperature） and the simulated variations were then compared with the observed data. Third, the z 0h scheme that performed best （i.e., Y07） was then selected to replace the defaulted one （i.e., Z98）; the revised scheme and the superiority of Y07 over Z98 was further demonstrated by comparing the simulated results with the observed data. Admittedly, the revised model did a relatively poor job of simulating the diurnal variations of surface soil heat flux, and nighttime soil temperature was also underestimated, calling for further improvement of the model for desert regions.

关键词： common land model (CoLM) parameter parameterization scheme taklimakan desert

OSL chronology reveals Late Pleistocene floods and their impact on landform evolution in the lower reaches of the Keriya River in the taklimakan desert

在线全文

学校读者我要写书评

暂无评论

Journal of Geographical Sciences 2023年第5期33卷 945-960页

作者： ZHANG Feng WANG Jiao MA Li Dilibaier TUERSUN College of Geography and Remote Sensing Sciences Xinjiang Key Laboratory of Oasis EcologyXinjiang UniversityUrumqi830046China

The impacts of climate change on the relationship between fluvial processes and dune landform evolution have been ***,the chronology data used to examine this relationship are *** Keriya River has a glacial origin in the Kunlun Mountains on the south margin of the Tarim *** river flows into the taklimakan desert,the second largest shifting-dune desert in the *** dry channels and shifting dunes in this area provide an ideal opportunity to investigate fluvial and aeolian landform evolution processes and their relationship with climate *** investigated this area during 2008-2011 and obtained 18 fluvial sediment samples from 16 sections for optically stimulated luminescence(OSL)*** results show that the ages ranged from 3.4-44.1 *** of the samples(13)were Holocene in age,around 11 ka,8-9 ka,5-6.5 ka,4.6 ka,and 3.4-3.7 ka and were distributed along ancient river channels around sites of Yuansha and *** samples close to the Hotan River(38-47 ka)fall within the Marine Isotope Stage 3(MIS3).Three samples(from one section)were located near ancient channels flowing towards the Yuansha Site and had ages of around 14.5 ka,i.e.,during the Last Glacial Maximum(LGM).The analyses of the sediment samples and OSL ages suggest that the Keriya River flooded in the Holocene,the LGM,and *** sediments provided the source material for the dunes,and fluvial processes affected the landform evolution in the lower Keriya *** results suggest that most of the dunes covered in fluvial sediments in the lower reaches and the area west of the Keriya River developed since the *** differs from the results of previous studies,which suggested that they developed since the Han(202BC-220AD)and Tang(618-907AD)*** OSL ages of the fluvial sediments are consistent with the reported deglaciation(after glacial advance)ages in the alpine mountains surrounding the Tarim *** suggests that climate fluctuations may h

关键词： taklimakan desert flood inundation dunes MIS3 LGM Holocene deglaciation

Observation of saltation activity at Tazhong area in taklimakan desert,China

在线全文

学校读者我要写书评

暂无评论

Journal of Arid Land 2013年第1期5卷 32-41页

作者： Ali MAMTIMIN Institute of desert Meteorology China Meteorological Administration desert Atmosphere and Environment Observation Experiment of taklimakan Station

A two-year field observation of saltation activity was carried out at Tazhong area, the hinterland area of the taklimakan desert with highly frequent dust storms. From 1 September 2008 to 31 August 2010, a piezoelectric saltation sensor （Sensit） was used to continuously collect the data on saltation activity at a level sand surface. Analysis on the data suggests that saltation activity can occur at any time of the year when conditions are favorable; however, the necessary conditions are rarely satisfied in most time. In the daytime of spring or summer, saltation activity can persist even over a continuous one-hour-or-so period. It is found that, from 1 September 2008 to 31 August 2010, saltation activity accounts for more than 3% of the total yearly time, and it tends to peak in spring and summer months with strong winds. During winter months when winds are weak, however, it is often at a minimum. It seems that precipitation does not appear to be significant in reducing saltation activity in arid regions like Tazhong.

关键词： saltation activity aeolian sand transport piezoelectric saltation sensor (Sensit) Tazhong taklimakan desert

Impacts of Irrigation and Vegetation Growth on Summer Rainfall in the taklimakan desert

在线全文

学校读者我要写书评

暂无评论

Advances in Atmospheric Sciences 2021年第11期38卷 1863-1872页

作者： Dongze XU Yanluan LIN Ministry of Education Key Laboratory for Earth System Modeling Department of Earth System ScienceTsinghua UniversityBeijing 100084China

In recent decades,a greening tendency due to increased vegetation has been noted around the taklimakan desert(TD),but the impact of such a change on the local hydrological cycle remains ***,we investigate the response of the local hydrological cycle and atmospheric circulation to a green TD in summer using a pair of global climate model(Community Earth System Model version 1.2.1)*** enough irrigation to support vegetation growth in the TD,the modeling suggests first,that significant increases in local precipitation are attributed to enhanced local recycling of water,and second,that there is a corresponding decrease of local surface *** the other hand,irrigation and vegetation growth in this low-lying desert have negligible impacts on the large-scale circulation and thus the moisture convergence for enhanced *** is also found that the green TD can only be sustained by a large amount of irrigation water supply since only about one-third of the deployed water can be“recycled”*** this,devising a way to encapsulate the irrigated water within the desert to ensure more efficient water recycling is key for maintaining a sustainable,greening TD.

关键词： vegetation irrigation taklimakan desert precipitation CESM

Observations of several characteristics of aeolian sand movement in the taklimakan desert

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2004年第1期47卷 86-96页

作者： HAN Zhiwen DONG Zhibao WANG Tao CHEN Guangting YAN Changzhen YAO Zhengyi Key Laboratory of desert and desertification Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China

With both sides of the taklimakan desert highway line as the study area, three typical aeolian sand landforms, i.e. complex dune ridge, barchan dune and flat sand land, were selected as sand beds for the observation, analysis and research of the characteristics of aeolian sand movement such as aeolian sand stream structure, sand transport intensity, etc. in the taklimakan desert. The results show that there is a linear relation between the height and the log of sand transport rate over transverse dune chain, longitudinal dune ridge and flat sand land, i.e. the sand transport percentage decreases exponentially with increasing height. Sand transport rate within the 10 cm height above the bed surface accounts for 80%-95% of the total sand transport rate of the observed height (40 cm), while the sand transport rate in 20 cm occupies 98% of the total amount. Sand transport rate (g·cm-1·min-1) differs greatly with respect to different landform types and different topographic positions. Based on the investigation and analysis on aeolian sand landform origin, morphological type and distribution feature, the two typical landform assemblages, complex transverse dune chain-alluvial plain and huge longitudinal dune ridge-interridge lowland in the taklimakan desert were divided into several characteristic zones of aeolian sand movement states. From this one can qualitatively judge the types and severities of sand disasters at various topographic positions in the engineering installation region and further put forward concrete schemes and measures to control sand damages.

关键词： taklimakan desert aeolian sand stream structure sand transport intensity state of aeolian sand stream movement

Stable oxygen-hydrogen isotopes reveal water use strategies of Tamarix taklamakanensis in the taklimakan desert, China

在线全文

学校读者我要写书评

暂无评论

Journal of Arid Land 2020年第1期12卷 115-129页

作者： DONG Zhengwu LI Shengyu ZHAO Ying LEI Jiaqiang WANG Yongdong LICongjuan Xinjiang Institute of Ecology and Geography Chinese Academy of SciencesUrumqi 830011China College of Resources and Environment Science Xinjiang UniversityUrumqi 830046China College of Life Science Xinjiang Normal UniversityUrumqi 830054China University of Chinese Academy of Sciences Beijing 100049China College of Resources and Environmental Engineering Ludong UniversityYantai 264025China

Tamarix taklamakanensis,a dominant species in the taklimakan desert of China,plays a crucial role in stabilizing sand dunes and maintaining regional ecosystem *** study aimed to determine the water use strategies of *** in the taklimakan desert under a falling groundwater *** typical *** nabkha habitats(sandy desert of Tazhong site,saline desert-alluvial plain of Qiemo site,desert-oasis ecotone of Qira site and desert-oasis ecotone of Aral site)were selected with different climate,soil,groundwater and plant cover *** isotope values of hydrogen and oxygen were measured for plant xylem water,soil water(soil depths within 0–500 cm),snowmelt water and groundwater in the different *** potential water sources for ***,defined as shallow,middle and deep soil water,as well as groundwater,were investigated using a Bayesian isotope mixing *** was found that groundwater in the taklimakan desert was not completely recharged by precipitation,but through the river runoff from snowmelt water in the nearby mountain *** surface soil water content was quickly depleted by strong evaporation,groundwater depth was relatively shallow and the height of *** nabkha was relatively low,thus *** primarily utilized the middle(23%±1%)and deep(31%±5%)soil water and groundwater(36%±2%)within the sandy desert *** mainly used the deep soil water(55%±4%)and a small amount of groundwater(25%±2%)within the saline desert-alluvial plain habitat,where the soil water content was relatively high and the groundwater depth was *** contrast,within the desert-oasis ecotone in the Qira and Aral sites,*** primarily utilized the deep soil water(35%±1%and 38%±2%,respectively)and may also use groundwater because the height of *** nabkha was relatively high in these habitats and the soil water content was relatively low,which is associated

关键词： Tamarix taklamakanensis water use strategies stable isotopes Bayesian isotope mixing model deep soil water groundwater taklimakan desert

A Field Experiment on Dust Emission by Wind Erosion in the taklimakan desert

在线全文

学校读者我要写书评

暂无评论

Acta meteorologica Sinica 2012年第2期26卷 241-249页

作者：杨兴华何清艾力.买买提依明霍文刘新春 STRAKE Miriam Institute of desert Meteorology China Meteorological Administration desert Atmosphere and Environment Observation Experiment of taklimakan Station Ruprecht Karls University of Heidelberg

Dust emission by wind erosion in surface is a serious problem in many arid regions around the world,and it is harmful to the ecological environment,human health,and social *** monitor the characteristics of saltation activity and to calculate the threshold wind velocity and sediment discharge under field conditions have significance on the research of dust emission by wind ***,a field experiment was conducted over the flat sand in the hinterland of the taklimakan *** sampling system was installed on the flat sand surface at Tazhong,consisting of a meteorological tower with a height of 2 m,a piezoelectric saltation sensor（Sensit）,and a Big Spring Number Eight（BSNE） sampler *** of saltation activity was recorded every second using the *** BSNE station consisted of five BSNE samplers with the lowest sampler at 0.05 m and the highest sampler at 1.0 m above the soil *** was collected from the samplers every 24 *** is found that saltation activity was detected for only 21.5% of the hours measured,and the longest period of saltation activity occurring continuously was not longer than 5 min under the field *** threshold wind velocity was variable,its minimum value was 4.9 m s 1,the maximum value was 9.2 m s 1,and the average value was 7.0 m s *** threshold wind velocity presented a positive linear increase during the measurement *** observation site had a sediment discharge of 82.1 kg m 1 over a period of 24 *** on hourly saltation counts,hourly sediment discharge was ***,there was no obvious linear or other functional relationship between the hourly sediment discharge and wind *** results show that the changes of sediment discharge do not quite depend on wind velocity.

关键词： wind erosion saltation activity threshold wind velocity sediment discharge taklimakan desert