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1.
作物气候风险研究:以河南省棉花为例 总被引：1，自引：0，他引：1
1 Introduction In the past 100 years the global temperature rose sharply due to the increase of greenhouse gas emissions into the atmosphere. The mean ground temperature rose by 0.5–0.6°C in the 20th century and 0.3–0.4°C in the last 20 years of the c… 相似文献
2.
According to the textual research into the historical documents dominated by archives yearly, as well as the verification with several other kinds of data, the later or earlier starting time of the rainy seasons in Yunnan during 1711-1982 has been reconstructed. The analysis indicates that there are obvious fluctuations in the starting date of the rainy seasons in Yunnan in a year or years, and long fluctuation on the decadal scale. The rainy season comes earlier in the early 18th century, later in the 19th century and earlier again in the 20th century. This reflects to a certain degree the gradual change of the summer monsoon in Yunnan. There exists an obvious quasi-3 years cycle, which is related to EI-Nino＇s quasi-3 years cycle, and a 11.3-year cycle which is notably related to the 11-year cycle of the solar activity of starting date of the rainy seasons in Yunnan. Meanwhile, the dissertation finds that the EI-Nino is very important to the starting date of the rainy seasons in Yunnan. The starting date of the rainy seasons in Yunnan often comes later or normally in the year of EI-Nino. However, there is an obvious imperfect period in such influence, which in turn may mean that there is a certain fluctuation in the effect of ENSO on Asian summer monsoon. 相似文献
3.
The Medieval Climate Anomaly(MCA, AD950–1250) is the most recent warm period lasting for several hundred years and is regarded as a reference scenario when studying the impact of and adaptation to global and regional warming. In this study, we investigated the characteristics of temperature variations on decadal–centennial scales during the MCA for four regions(Northeast, Northwest, Central-east, and Tibetan Plateau) in China, based on high-resolution temperature reconstructions and related warm–cold records from historical documents. The ensemble empirical mode decomposition method is used to analyze the time series. The results showed that for China as a whole, the longest warm period during the last 2000 years occurred in the 10 th–13 th centuries, although there were multi-decadal cold intervals in the middle to late 12 th century. However, in the beginning and ending decades, warm peaks and phases on the decadal scale of the MCA for different regions were not consistent with each other. On the inter-decadal scale, regional temperature variations were similar from 950 to 1130; moreover, their amplitudes became smaller, and the phases did not agree well from 1130 to 1250. On the multi-decadal to centennial scale, all four regions began to warm in the early 10 th century and experienced two cold intervals during the MCA. However, the Northwest and Central-east China were in step with each other while the warm periods in the Northeast China and Tibetan Plateau ended about 40-50 years earlier. On the multi-centennial scale, the mean temperature difference between the MCA and Little Ice Age was significant in Northeast and Central-east China but not in the Northwest China and Tibetan Plateau. Compared to the mean temperature of the 20 th century, a comparable warmth in the MCA was found in the Central-east China, but there was a little cooling in Northeast China; meanwhile, there were significantly lower temperatures in Northwest China and Tibetan Plateau. 相似文献
4.
XINGKexia GUOHuaicheng SUNYanfeng HUANGYongtai 《地理学报(英文版)》2005,15(1):37-43
Water-quality deterioration and eutrophication of the Lake Dianchi have acquired more and more attention in the last few decades. In this paper, the spatial and temporal eutrophication status of the Lake Dianchi was assessed. The comprehensive trophic state index was chosen to assess the trophic status of the Lake Dianchi in the past 13 years. The result reveals that the trophic condition of Caohai is more serious than that of Waihai. Most of time Caohai was in extremely hypereutrophic state from 1988 to 2000. The trophic condition of Waihai had a worsening tendency from 1988 to 2000. Waihai was in eutrophic state before 1995, but it got in a hypereutrophic state after 1995. It was pointed out that TN and TP were the two biggest contributors of CTSIM in both Caohai and Waihai. 相似文献
5.
Mountains have been described as the water towers of the world. Almost all major rivers have their sources in mountains; glaciers are important water resources that contribute meltwater to river discharge. Glaciers participate in the global water cycle and, with their solid water storage, are an important component of the water balance. As solid reservoirs, glaciers continue to receive the mass nourishment of solid precipitation from the atmosphere, and their meltwater feed and regulate river discharge. Physical changes in glaciers are an indicator of climate change. Over the past half century, the global temperature has increased by 1–2 °C, which emphasizes the urgent task of monitoring glaciers and predicting their trend. As an example, we have investigated, researched, and surveyed Glacier No.1 in the Urumqi River source, Tianshan (abbr. Glacier No.1 Tianshan or Glacier No.1) for half a century. We have found an increase by degrees of the glacial regression during the last 400 years and discovered a terminal moraine which is forming today. The global temperature is rising continually, while the local glacial temperature is 0.4 times that of the global temperature change. Thus, we forecast that Glacier No.1 Tianshan will disappear during the late 21st Century (2074–2100 A.D.). 相似文献
6.
Modeling Arctic Ocean heat transport and warming episodes in the 20th century caused by the intruding Atlantic Water 
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下载免费PDF全文 Jun Takahashi Tatsuo Suzuki Igor V Polyakov Kohei Mizobata Moto Ikeda Fancois J.Saucier Markus Meier 《极地研究》2008,19(2):159-167
This study investigates the Arctic Ocean warming episodes in the 20th century using both a high-resolution coupled global climate model and historical observations .The model,with no flux adjustment,reproduces well the Atlantic Water core temperature(AWCT) in the Arctic Ocean and shows that four largest decadal-scale warming episodes occurred in the 1930s,70s,80s,and 90s,in agreement with the hydrographic observational data.The difference is that there was no pre-warming prior to the 1930s episode,while there were two pre-warming episodes in the 1970s and 80s prior to the 1990s,leading the 1990s into the largest and prolonged warming in the 20th century.Over the last century,the simulated heat transport via Fram Strait and the Barents Sea was estimated to be,on average,31.32 TW and 14.82 TW,respectively,while the Bering Strait also provides 15.94 TW heat into the western Arctic Ocean.Heat transport into the Arctic Ocean by the Atlantic Water via Fram Strait and the Barents Sea correlates significantly with AWCT(C=0.75 ) at 0- lag.The modeled North Atlantic Oscillation(NAO) index has a significant correlation with the heat transport(C=0.37).The observed AWCT has a significant correlation with both the modeled AWCT(C=0.49) and the heat transport(C=0.41). However,the modeled NAO index does not significantly correlate with either the observed AWCT(C=0.03) or modeled AWCT(C=0.16) at a zero-lag,indicating that the Arctic climate system is far more complex than expected. 相似文献
7.
Based on the daily maximum temperature data covering the period 1961-2005, temporal and spatial characteristics and their changing in mean annual and monthly high temperature days（HTDs）and the mean daily maximum temperature（MDMT）during annual and monthly HTDs in East China were studied.The results show that the mean annual HTDs were 15.1 and the MDMT during annual HTDs was 36.3℃in the past 45 years.Both the mean annual HTDs and the MDMT during annual HTDs were negative anomaly in the1980s and positive anomaly in the other periods of time,oscillating with a cycle of about 12-15 years.The mean annual HTDs were more in the southern part,but less in the northern part of East China.The MDMT during annual HTDs was higher in Zhejiang,Anhui and Jiangxi provinces in the central and western parts of East China.The high temperature process（HTP） was more in the southwestern part,but less in northeastern part of East China.Both the HTDs and the numbers of HTP were at most in July,and the MDMT during monthly HTDs was also the highest in July.In the first 5 years of the 21st century,the mean annual HTDs and the MDMT during annual HTDs increased at most of the stations,both the mean monthly HTDs and the MDMT during monthly HTDs were positive anomalies from April to October,the number of each type of HTP generally was at most and the MDMT in each type of HTP was also the highest. 相似文献
8.
Global historical land use scenarios are widely used to simulate the climatic and ecological effects of changes in land cover; however, reliability evaluation of these scenarios for data on China's forests is missing. By using a historical document-derived Chinese forest dataset(CHFD) for the years 1700–2000, we evaluated the reliability of data on forests in China over three global scenarios—SAGE(Center for Sustainability and the Global Environment), PJ(Pongratz Julia), and KK10(Kaplan and Krumhardt 2010)—through trend-related, quantitative, and spatial comparisons. The results show the following:(1) Although the area occupied by forests in China in the SAGE, PJ, KK10, and CHFD datasets decreased over the past 300 years, there were large differences between global scenarios and CHFD. The area occupied by forests in China in the SAGE scenario for 1700–1990 was 20%–40% more than that according to CHFD, and that occupied by forests in the KK10 from 1700 to 1850 was 32%–46% greater than that in CHFD. The difference between the PJ and CHFD was lower than 20% for most years.(2) Large differences were detected at the provincial and grid cell scales, where the PJ scenario was closer to CHFD in terms of total forested area. Provinces with large differences in terms of trend and quantity were 84% and 92% of all provinces, respectively. Grid cells with relative differences greater than 70% accounted for 60%–80% of all grids.(3) These global historical land use scenarios do not accurately reveal the spatiotemporal pattern of Chinese forests due to differences in the data sources, methods of reconstruction, and spatial scales. 相似文献
9.
《寒旱区科学》2016,(6)
正Academician Guodong Cheng,the Chief-Editor of Sciences in Cold and Arid Regions,was honored with the Lifetime Achievement Award of International Permafrost Association(IPA)in Evora,Portugal on 19 June 2014.The IPA awarded Professor Cheng to recognize his outstanding contributions in the field of frozen soil science and engineering research during the past one-half century. 相似文献
10.
The town of Agura,a typical region in Horqin Sandy Land,was selected as the study area in this paper.Using 12 remote sensing images and climatic data from the past 20 years,the effects of climate change on surface environments were analyzed.The impact indices of climatic factors,along with their corresponding ranks,were used to characterize the responses of different types of surface environments to climate change.Results show that in the past 20 years,the surface environments of the study area have been deteriorating.Furthermore,there is a positive relationship between the changes in surface environments and those in climatic factors.Various climatic factors influence surface environments in different ways and at different levels.The most sensitive factor is relative humidity,followed by precipitation and evaporation.Overall,moisture is the key factor that affects the changes in surface environments of arid and semi-arid areas. 相似文献
11.
Based on air temperature observation data from 32 meteorological stations, temperature changes in the middle Qinling Mountains from 1959 to 2016 were analysed with respect to the north-south, seasonal and altitude differences. Our research mainly showed the following results. The annual temperature(TA) rose approximately 0.26℃/10 a within the past 58 years. This warming trend was stronger on the northern slope than on the southern slope, and a warming trend reversal occurred in 1994 on the northern slope, which was three years earlier than on the southern slope. The temperature changes for the four seasons were not synchronized, and the trend in spring contributed the most to the TA trend, followed by winter, autumn, and summer. The temperature difference between summer and winter(TDSW) decreased significantly over the past 58 years. The temperature change in the middle Qinling Mountains was clearly dependent on altitude. With increases in altitude, the TA increased gradually and became stronger while the TDSW decreased gradually and became weaker. Differences in temperature change between the north and south were mainly observed in low-altitude areas. With increase in altitude, the differences gradually tended to disappear. 相似文献
12.
长江源区地表水资源对气候变化的响应及趋势预测(英文) 总被引：2，自引：0，他引：2
In this paper,variations of surface water flow and its climatic causes in China are analyzed using hydrological and meteorological observational data,as well as the impact data set(version 2.0) published by the National Climate Center in November 2009.The results indicate that surface water resources showed an increasing trend in the source region of the Yangtze River over the past 51 years,especially after 2004.The trend was very clearly shown,and there were quasi-periods of 9 years and 22 years,where the Tibetan Plateau heating field enhanced the effect,and the plateau monsoon entered a strong period.Precipitation notably increased,and glacier melt water increased due to climate change,all of which are the main climatic causes for increases in water resources in the source region.Based on global climate model prediction,in the SRESA1B climate change scenarios,water resources are likely to increase in this region for the next 20 years. 相似文献
13.
Transport geography is a major branch of economic geography.It aims to study the spatial pattern of transport infrastructure along with the transport network,traffic organization,and passenger and cargo flow along with their evolution.Research on modern transport geography began in the early 20th century.During the last 100 years,important advances in transport geography have been achieved,and development in this field in China has kept pace with the rest of the world.Our predecessors have completed many fruitful and pioneering works in both theory and practice.In the leap-forward development phase of the transport industry over the past thirty years and particularly since the beginning of the 21 st century,many issues related to the transport network in China have become the focal points of research in various fields.Building on this background,researchers at the Institute of Geographic Sciences and Natural Resources Research,Chinese Academy of Sciences,studied the theoretical and practical issues of transport geography from the thematic and synthetic perspectives,characterized the spatial regularity of transport infrastructure,and described its relationship with the spatial organization of the social-economic system.Based on the results,the Series of Transport Geography and Regional Development was compiled and published. 相似文献
14.
The proxy records on typhoons in the Yangtze River Delta from 1644 to 1949AD were extracted from historical chorographies in the Qing Dynasty and the Republic of China Period.In reference to the basic principles for identifying historical typhoons,time series on the Yangtze River Delta over a period of 306 years were developed.The conclusions are as follows.(1) There were a total of 241 typhoons from 1644 to 1949AD.Using the historical chorographies from 1884 to 1949AD,the number of typhoons was 65,equal to 87.8% recorded by meteorological observation.The number of years with differences in typhoon activities reconstructed using two ways no more than once is 55,reaching 83.3% in the period from 1884 to 1949AD.This result means the series of historical typhoons reconstructed using historical chorographies can represent the change of typhoon activities over years.(2) The average number of typhoon activities is 0.79 times per year from 1644 to 1949AD,and they show an increasing trend.These 306 years can be divided into three periods by the average number of typhoon activities:it is low from 1644 to 1784AD,and more typhoon activities are found from 1785 to 1904AD.It is worth noting that the number of typhoon activities reaches the summit in the last period,which is 1.2 times per year from 1905 to 1949AD.(3) Before the 20th century,the number of typhoon activities in warm periods is less than the number of cold periods.However,the number of typhoon activities increased dramatically in the early 20th century.Comparing the typhoon activities with El Ni o events,the data show that the number of typhoon activities did not increase when El Ni o occurred. 相似文献
15.
The concentration variation features of sea salt ions and non sea salt ions in a firn core recovered from Princess Elizabeth Land, East Antarctica 下载免费PDF全文
下载免费PDF全文 A 51.85 m firn core drilled in Princess Elizabeth Land, Antarctica, during the 1996-1997 Chinese First Antarctic Inland Expedition, has been measured for δ 18 O and major ions. Based on the high quality data of the seasonal variations of major ions, the firn core was dated with errors within ±3 years. The 51.85 m firn core record extends for 251 years (A. D. 1745-1996). The results of the glaciochemistry data of the firn core show that the mean concentrations of Cl -, Na + and Mg 2+ are similar to those reported from other coastal areas in East Antarctica. However, mean concentrations of Ca 2+ are much higher than those reported from other regions, this anomaly phenomenon may be related to the strong local terrestrial sources. It is found that the variations of three kinds of sea salt ions (Cl -, Na + and Mg 2+ ) in the past 150 years show very similarly rising trends, which may be the results the Southern Hemisphere warming in the past century. 相似文献
16.
For thousands of years, people have been trying to promote benefit and abolish harm to the Yellow River by means of various activities such as flood control and water abstraction. However, after the last decade of the 20th century, it was noticed that the… 相似文献
17.
Soil salinization research in China: Advances and prospects 总被引：14，自引：0，他引：14
With the environmental deterioration caused by the advance of climate change, soil salinization is a serious and growing global problem. Currently about 7% of the world＇s land surface is threatened by salinization. China is a country whose soils are severely affected by this problem, which, due to its extensive area, and wide distribution poses a serious threat to regional agricultural development. In this review, we summarize the framework for soil salinization research in China over the past 70 years, assess the weaknesses of existing research in both a domestic and international context, highlight the trends and key findings of global research about saline soils over the past 30 years, and propose six major fields and directions for future research on saline soil. 相似文献
18.
Studies of the past climate variation on the Tibetan Plateau(TP) are currently limited in number and low in density and temporal resolution. We investigated the climate condition from about 400 years before present(B.P.) in the central TP at the shore of Co(means "lake") Nag using aeolian sediments. A 2.7-m sand profile with 57 sediment samples and six optically stimulated luminescence(OSL) samples were studied through grain-size analysis, geochemical elements and parameters, and depositional rate estimation. A previous assumption was verified that sand deposition at the shore of Lake Co Nag originated from hills to the east. Two significant wet periods between 90–140 and about 380 years B.P. were indicated by the variation of element profiles and sediment depositional rates. Aeolian activity is sensitive to variations from different seasonal changing patterns of climate factors in the study area, and aeolian sediments respond differently to climate conditions during the cold little ice age(LIA) and the warm 20 th century. Present day dry seasons of winter and spring might be much warmer and drier compared to seasons of 400 years ago although summer precipitation has increased, resulting in significantly more aeolian activity and higher depositional rate(about 6 times compared to 380–240 years ago) of sandy sediments. Aeolian problems like blown-sand deposition and desertification may be worse in a projected warming future in the central TP as well as other cold and high altitude regions. Our results suggest an agreement with environmental evolution during the little ice age and the 20 th century in a broader scale on the TP. 相似文献
19.
LI Wenhua 《资源与生态学报(英文版)》2022,13(1):1-1
Humanity turns to a new chapter in 2022. As proud as we are of rapid developments in economics, science, and technology, we are equally concerned about such global issues as biodiversity conservation and the global pandemic of Covid-19. The unprecedented impact human activities have exerted on the global climate system is clearly underscored by the data from the World Meteorological Organization: The previous fifty years since 1970 have been the warmest of the past 2000 years. 相似文献
20.
Samuli Helama Jianmin Jiang Johanna Korhonen Jari Holopainen Mauri Timonen 《地理学报(英文版)》2013,23(6):1069-1079
Cryophenological records （i.e. observational series of freeze and breakup dates of ice） are of great importance when assessing the environmental variations in cold regions. Here we employed the extraordinarily long observational records of river ice breakup dates and air temperatures in northern Fennoscandia to examine their interrelations since 1802. Historical observations, along with modern data, comprise the informational setting for this analysis carried out using t-test. Temperature history of April-May season was used as cli- matic counterpart for the breakup timings. Both records （temperature and breakup） showed seven sub-periods during which their local means were distinctly different relative to preced- ing and subsequent sub-periods. The starting and ending years of these sub-periods oc- curred in temporal agreement. The main findings of this study are summarized as follows： （1） the synchrony between the temperature and river ice breakup records ruled out the possibility that the changes would have occurred due to quality of the historical series （i.e. inhomoge- neity problems often linked to historical time-series）; （2） the studied records agreed to show lower spring temperatures and later river ice breakups during the 19th century, in comparison to the 20th century conditions, evidencing the prevalence of cooler spring temperatures in the study region, in agreement with the concept of the Little Ice Age （1570-1900） climate in North-West Europe; （3） the most recent sub-period demonstrate the highest spring tem- peratures with concomitantly earliest river ice breakups, showing the relative warmth of the current springtime climate in the study region in the context of the past two centuries; （4） the effects of anthropogenic changes in the river environment （e.g. construction and demolition of dams） during the 20th century should be considered for non-climatic variations in the breakup records; （5） this study emphasizes the importance of multi-centurial （i.e. historical） cryo- phenological information for highly interesting viewpoints of climate and environmental his- tory. 相似文献