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spatio-temporal variation and propagation direction of coal fire in Jharia Coalfield,India by satellite-based multi-temporal night-time land surface temperature imaging

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International Journal of Mining Science and Technology 2021年第5期31卷 765-778页

作者： Narendra Singh R.S.Chatterjee Dheeraj Kumar D.C.Panigrahi Department of Mining Engineering Indian Institute of Technology(Indian School of Mines)Dhanbad 826004India Geosciences Department Indian Institute of Remote SensingDehradun 248001India

In this paper,the spatio-temporal variation and propagation direction of coal fire were studied in the Jharia Coalfield(JCF),India during 2006–2015 through satellite-based night-time land surface temperature(LST)*** LST was retrieved from Advanced Spaceborne Thermal Emission and Reflection Radiometer(ASTER)night-time thermal-infrared data by a robust split-window algorithm based on scene-specific regression coefficients,band-specific hybrid emissivity,and night-time atmospheric *** LST-profile-based coal fire detection algorithm was formulated through statistical analysis of the LST values along multiple transects across diverse coal fire locations in the JCF in order to compute date-specific threshold temperatures for separating thermally-anomalous and background *** algorithm efficiently separates surface fire,subsurface fire,and thermally-anomalous transitional *** the observation period,it was noticed that the coal fire area increased significantly,which resulted from new coal fire at many places owing to extensive opencast-mining *** was observed that the fire propagation occurred primarily along the dip direction of the coal *** places,lateral-propagation of limited spatial extent was also observed along the strike direction possibly due to spatial continuity of the coal seams along ***,the opencast-mining activities carried out during 2009–2015 and the structurally weak planes facilitated the fire propagation.

关键词： Satellite-based night-time imaging Land surface temperature Coal fire spatio-temporal variation Propagation direction Jharia Coalfield

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spatio-temporal variation in China's climatic seasons from 1951 to 2017

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Journal of Geographical Sciences 2020年第9期30卷 1387-1400页

作者： MA Bin ZHANG Bo JIA Lige College of Geography and Environmental Science Northwest Normal UniversityLanzhou 730070.China Tourism College Innet Mongolia Normal UniversityHuhhot 010022China

In this paper,meteorological industry standard,daily mean temperature,and an improved multiple regression model are used to calculate China's climatic seasons,not only to help understand their spatio-temporal distribution,but also to provide a reference for China's climatic regionalization and crop *** is found that the improved multiple regression model can accurately show the spatial distribution of climatic *** main results are as *** are four climatic seasonal regions in China,namely,the perennial-winter,no-winter,no-summer and discernible regions,and their ranges basically remained stable from 1951 to *** cumulative anomaly curve of the four climatic seasonal regions clarifies that the trend of China's climatic seasonal regions turned in 1994,after which the area of the perennial-winter and no-summer regions narrowed and the no-winter and discernible regions *** number of sites with significantly reduced winter duration is the largest,followed by the number of sites with increased summer duration,and the number of sites with large changes in spring and autumn is the *** advances and autumn is postponed due to the shortened winter and lengthened summer *** with significant change in seasonal duration are mainly distributed in Northwest China,the Sichuan Basin,the Huanghe-Huaihe-Haihe(Huang-Huai-Hai) Plain,the Northeast China Plain,and the Southeast Coast.

关键词： climatic seasons revised multiple regression model spatio-temporal variation China

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spatio-temporal variation of Soil Respiration and Its Driving Factors in Semi-arid Regions of North China

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Chinese Geographical Science 2018年第1期28卷 12-24页

作者： ZENG Xinhua SONG Yigang ZHANG Wanjun HE Shengbing College of Environmental Science and Engineering Shanghai Jiaotong University Key Laboratory of Agricultural Water Resources Center for Agricultural Resources Research Institute of Genetics and Developmental Biology Chinese Academy of Sciences Shanghai Chenshan Plant Science Research Center Chinese Academy of Sciences

Soil respiration （SR） is the second-largest flux in ecosystem carbon cycling. Due to the large spatio-temporal variability of environmental factors, SR varied among different vegetation types, thereby impeding accurate estimation of CO2 emissions via SR. However, studies on spatio-temporal variation of SR are still scarce for semi-arid regions of North China. In this study, we conducted 12-month SR measurements in six land-use types, including two secondary forests （Populus tomentosa （PT） and Robinia pseudoacacia （RP））, three artificial plantations （Armeniaca sibirica （AS）, Punica granatum （PG） and Ziziphusjujuba （Z J）） and one natural grassland （GR）, to quantify spatio-temporal variation of SR and distinguish its controlling factors. Results indicated that SR exhibited distinct sea- sonal patterns for the six sites. Soil respiration peaked in August 2012 and bottomed in April 2013. The temporal coefficient of variation （CI0 of SR for the six sites ranged from 76.98% to 94.08%, while the spatial CV of SR ranged from 20.28% to 72.97% across the 12-month measurement. Soil temperature and soil moisture were the major controlling factors of temporal variation of SR in the six sites, while spatial variation in SR was mainly caused by the differences in soil total nitrogen （STN）, soil organic carbon （SOC）, net photosynthesis rate, and fine root biomass. Our results show that the annual average SR and Q10 （temperature sensitivity of soil respira- tion） values tended to decrease from secondary forests and grassland to plantations, indicating that the conversion of natural ecosystems to man-made ecosystems may reduce CO2 emissions and SR temperature sensitivity. Due to the high spatio-temporal variation of SR in our study area, care should be taken when converting secondary forests and grassland to plantations from the point view of accurately quantifying C02 emissions via SR at regional scales.

关键词： soil respiration spatio-temporal variation substrate availability temperature sensitivity global carbon cycle North China

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spatio-temporal variation OF ACTUAL EVAPOTRANSPIRATION AND ITS RELATION WITH CLIMATE PARAMETERS IN THE PEARL RIVER BASIN,CHINA

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Journal of Tropical Meteorology 2017年第1期23卷 81-90页

作者：吴萍李修仓苏布达占明锦王艳君姜彤 Chinese Academy of Meteorological Sciences Beijing 100081 China Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science&TechnologyNanjing210044 China National Climate Center China Meteorological AdministrationBeijing 100081 China State Key Laboratory of Desert and Oasis Ecology Xinjiang Institute of Ecology and GeographyChinese Academy of SciencesUrumqi 830011 China Jiangxi Province Climate Center Nanchang 330046 China

spatio-temporal variation of actual evapotranspiration(ETa) in the Pearl River basin from 1961 to 2010 are analyzed based on daily data from 60 national observed stations. ETa is calculated by the Advection-Aridity model(AA model) in the current study, and Mann-Kendall test(MK) and Inverse Distance Weighted interpolation method(IDW)were applied to detect the trends and spatial variation pattern. The relations of ETa with climate parameters and radiation/dynamic terms are analyzed by Person correlation method. Our findings are shown as follows: 1) Mean annual ETa in the Pearl River basin is about 665.6 mm/a. It has significantly decreased in 1961-2010 at a rate of-24.3mm/10 a. Seasonally, negative trends of summer and autumn ETa are higher than that of spring and winter. 2) The value of ETa is higher in the southeast coastal area than in the northwest region of the Pearl River basin, while the latter has shown the strongest negative trend. 3) Negative trends of ETa in the Pearl River basin are most probably due to decreasing radiation term and increasing dynamic term. The decrease of the radiation term is related with declining diurnal temperature range and sunshine duration, and rising atmospheric pressure as well. The contribution of dynamic term comes from increasing average temperature, maximum and minimum temperatures in the basin. Meanwhile, the decreasing average wind speed weakens dynamic term and finally, to a certain extent, it slows down the negative trend of the ETa.

关键词： complementary relationship theory advection-aridity model actual evapotranspiration spatio-temporal variation Pearl River basin

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spatio-temporal variation and focal mechanism of the Wenchuan M_S8.0 earthquake sequence

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Earthquake Science 2009年第2期22卷 109-117页

作者： Wanzheng Cheng Zhiwei Zhang Xiang Ruan Earthquake Prediction Institute Earthquake Administration of Sichuan Province Chengdu 610041 China

Based on abundant aftershock sequence data of the Wenchuan Ms8.0 earthquake on May 12, 2008, we studied the spatio-temporal variation process and segmentation rupture characteristic. Dense aftershocks distribute along Longmenshan central fault zone of NE direction and form a narrow strip with the length of 325 krn and the depth between several and 40 km. The depth profile （section of NW direction） vertical to the strike of aftershock zone （NE direction） shows anisomerous wedgy distribution characteristic of afiershock concentrated regions; it is related to the force form of the Longmenshan nappe tectonic belt. The stronger aftershocks could be divided into northern segment and southern segment apparently and the focal depths of strong aftershocks in the 50 km area between northern segment and southern segment are shallower. It seems like ＇to be going to rupture＇ segment. We also study focal mechanisms and segmentation of strong aftershocks. The principal compressive stress azimuth of aftershock area is WNW direction and the faulting types of aftershocks at southern and northern segment have the same proportion. Because afiershocks distribute on different secondary faults, their focal mechanisms present complex local tectonic stress field. The faulting of seven strong earthquakes on the Longmenshan central fault is mainly characterized by thrust with the component of right-lateral strike-slip. Meantime six strong aftershocks on the Longmenshan back-range fault and Qingchuan fault present strike-slip faulting. At last we discuss the complex segmentation rupture mechanism of the Wenchuan earthquake.

关键词： Wenchuan earthquake strong aftershock spatio-temporal variation focal mechanism solution

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spatio-temporal variation and the driving forces of tea production in China over the last 30 years

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Journal of Geographical Sciences 2018年第3期28卷 275-290页

作者：肖智黄贤金臧正杨洪 School of Geographic and Oceanographic Sciences Nanjing University Kaili University Department of Geography and Environmental Science University of Reading

As a daily necessity and an important cash crop in China and many other countries, tea has received increasing attention. Using production concentration index model and in- dustry＇ s barycenter theory, we analyzed the spatio-temporal distribution of tea production and barycenter movement trajectory of tea plantations and production in China between 1986 and 2015. Driving forces of the movement were also analyzed. From 1986 to 2000, tea production in China＇s Mainland of grew slowly （by 210x103 t）. The continuous increase in tea yield per unit area was the primary contributor （more than 60%） to the growth in tea production during this period. Since China joined the World Trade Organization （WTO） in 2001, tea production has grown rapidly, by 1.59x106 t between 2001 and 2015. The increase in the tea plantations area is the main contributor. Over the last 30 years, the barycenters of tea production in China have moved westward from the Dongting Lake Plain to the eastern fringe of the Yun- nan-Guizhou Plateau. Guizhou, Guangxi, and Sichuan in southwestern China have gradually become regions of new concentrated tea plantations and main tea production provinces. Lower cost of land and labor in southwestern China are the main drivers of the westward movement of China＇s tea industry. In addition, supportive policies and the favorable natural geographical environment contribute to the westward movement of tea industry. Our research highlights the spatio-temporal variation of China＇s tea production in the last three decades. The result indicates importance to make appropriate policies to promote the development of tea industry in China.

关键词： tea industry spatio-temporal variation driving force China

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spatio-temporal variation of precipitation in the Three-River Headwater Region from 1961 to 2010

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Journal of Geographical Sciences 2013年第3期23卷 447-464页

作者： YI Xiangsheng LI Guosheng YIN Yanyu Institute of Geographic Sciences and Natural Resources Research CAS Beijing 100101 China University of Chinese Academy of Sciences Beijing 100049 China

Based on a monthly dataset of precipitation time series （1961-2010） from 12 me- teorological stations across the Three-River Headwater Region （THRHR） of Qinghai Province China, the spatio-temporal variation and abrupt change analysis of precipitation were exam- ined by using moving average, linear regression, spline interpolation, the Mann-Kendall test and so on. Major conclusions were as follows. （1） The long-term annual and seasonal pre- cipitation in the study area indicated an increasing trend with some oscillations during 1961-2010; however, the summer precipitation in the Lantsang （Lancang） River Headwater Region （LARHR）, and the autumn precipitation in the Yangtze River Headwater Region （YERHR） of the THRHR decreased in the same period. （2） The amount of annual precipita- tion in the THRHR and its three sub-headwater regions was greater in the 1980s and 2000s. The springs were fairly wet after the 1970s, while the summers were relatively wet in the 1960s, 1980s and 2000s. In addition, the amount of precipitation in the autumn was greater in the 1970s and 1980s, but it was relatively less for the winter precipitation, except in the 1990s （3） The normal values of spring, summer, winter and annual precipitation in the THRHR and its three sub-headwater regions all increased, but the normal value of summer precipitation in the LARHR had a negative trend and the normal value of winter precipitation declined in general. （4） The spring and winter precipitation increased in most of the THRHR. The summer autumn and annual precipitation increased mainly in the marginal area of the west and north and decreased in the regions of Yushu, Zaduo, Jiuzhi and Banma. （5） The spring and winter precipitation in the THRHR and its three sub-headwater regions showed an abrupt change, except for the spring precipitation in the YARHR. The abrupt changes of spring precipitation were mainly in the late 1980s and early 1990s, while the abrupt changes of winter precipita- tion were primary

关键词： precipitation spatio-temporal variation abrupt change analysis Three-River Headwater Region

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Estimation of ocean primary productivity and its spatio-temporal variation mechanism for East China Sea based on VGPM model

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Journal of Geographical Sciences 2004年第1期14卷 32-40页

作者： LIGuosheng GAOPing WANGFang LIANGQiang Inst.ofGeographicSciencesandNaturalResourcesResearch CASBeijing100101China

According to calculation results of ocean chlorophyll concentration based on SeaWiFS data by SeaBAM model and synchronous ship-measured data, this research set up an improved model for CaseⅠand CaseⅡwater bodies respectively. The monthly chlorophyll distribution in the East China Sea in 1998 was obtained from this improved model on calculation results of SeaBAM. The euphotic depth distribution in 1998 in the East China Sea is calculated by using remote sensing data of K 490 from SeaWiFS according to the relation between the euphotic depth and the oceanic diffuse attenuation coefficient. With data of ocean chlorophyll concentration, euphotic depth, ocean surface photosynthetic available radiation (PAR), daily photoperiod and optimal rate of daily carbon fixation within a water column, the monthly and annual primary productivity spatio-temporal distributions in the East China Sea in 1998 were obtained based on VGPM model. Based on analysis of those distributions, the conclusion can be drawn that there is a clear bimodality character of primary productivity in the monthly distribution in the East China Sea. In detail, the monthly distribution of primary productivity stays the lowest level in winter and rises rapidly to the peak in spring. It gets down a little in summer, and gets up a little in autumn. The daily average of primary productivity in the whole East China Sea is 560.03 mg/m 2 /d, which is far higher than the average of subtropical ocean areas. The annual average of primary productivity is 236.95 g/m 2 /a. The research on the seasonal variety mechanism of primary productivity shows that several factors that affect the spatio-temporal distribution may include the chlorophyll concentration distribution, temperature condition, the Yangtze River dilut

关键词： East China Sea primary productivity chlorophyll concentration remote sensing algorithm spatio-temporal variation mechanism

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spatio-temporal variations of Temperature and Precipitation During 1951–2019 in Arid and Semiarid Region, China

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Chinese Geographical Science 2022年第2期32卷 285-301页

作者： HUANG Yufei LU Chunyan LEI Yifan SU Yue SU Yanlin WANG Zili College of Computer and Information Sciences Fujian Agriculture and Forestry UniversityFuzhou 350002China Key Laboratory of Ecology and Resources Statistics of Fujian Province Universities Fujian Agriculture and Forestry UniversityFuzhou 350002China Statistical Information Research Center of Fujian Province Fujian Agriculture and Forestry UniversityFuzhou 350002China Research Centre of Resource and Environment Spatial Information Statistics of Fujian Province Fujian Agriculture and Forestry UniversityFuzhou 350002China

Understanding the spatio-temporal variations of temperature and precipitation in the arid and semiarid region of China(ASRC)is of great significance for promoting regional eco-environmental protection and *** this study,the annual and seasonal spatio-temporal patterns of change in average temperature and precipitation and their influencing factors in the ASRC were analyzed using the Mann-Kendall test,linear tendency estimation,accumulative anomaly and the Pearson’s correlation *** results showed that both annual average temperature and average annual precipitation increased in the ASRC during 1951–*** temperature rose by about 1.93℃and precipitation increased by about 24 *** seasonal average temperature presented a significant increase trend,and the seasonal precipitation was conspicuous ascension in spring and *** spatio-temporal patterns of change in temperature and precipitation differed,with the southwest area showing the most obvious variation in each *** changes in annual and seasonal average temperature and precipitation occurred mainly around the 1990 s and after 2000,*** circulation had an important effect on the trends and abrupt changes in temperature and *** East Asian summer monsoon had the largest impact on the trend of average annual temperature,as well as on the abrupt changes of annual average temperature and *** and precipitation changes in the ASRC were influenced by long-term and short-term as well as direct and indirect anthropogenic and natural *** study identifies the characteristics of spatio-temporal variations in temperature and precipitation in the ASRC and provides a scientific reference for the formulation of climate change responses.

关键词： multi-source remote sensing data temperature precipitation arid and semiarid region spatio-temporal variation atmospheric circulation

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GIS-based analysis of population exposure to PM2.5 air pollution-A case study of Beijing

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Journal of Environmental Sciences 2017年第9期29卷 48-53页

作者： Zhao Liu Meihui Xie Kun Tian Peichao Gao Institute of Geospatial Information Dep.of Civil Eng.Tsinghua Univ.Beijing 100084China

PM_（2.5）, formally defined as particulate matter with diameter less than 2.5 μm, is one of most harmful air pollutants threatening human health. Numerous epidemiological studies have shown that both short-term and long-term exposures to PM_（2.5） are strongly linked with respiratory diseases. In this study, various types of spatio-temporal data were collected and used to estimate the spatio-temporal variation of PM2.5 exposure in Beijing in 2014. The seasonal and daily variation of the population-weighted exposure level（PWEL） in 2014 was estimated and compared. The results show that the population exposure to ambient air pollution differs significantly in the four seasons, and the exposure levels in winter and spring are notably higher than the other seasons; the exposure level changes greatly from North to South, and each sub-district maintains similarity to neighboring sub-districts.

关键词： GIS Population exposure PM2.5 spatio-temporal variation

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