气候变化背景下1981-2010年中国玉米物候变化时空分异

基于中国玉米种植区内114个农气站1981-2010年的长序列物候观测数据,量化分析了玉米8个连续物候期的时空分异特征和相应的生长阶段长度变化规律。结果表明：1981-2010年间,玉米生育期内平均温度和有效积温(GDD）呈现增加趋势,降水量和日照时数呈现减少趋势。气候变化背景下,玉米物候期发生了显著变化。春玉米物候期以提前趋势为主,包括西北内陆玉米区春玉米、西南山地丘陵玉米区春玉米;夏玉米和春夏播玉米各物候期在不同区域均呈现推迟的趋势,西北内陆玉米区夏玉米各物候期推迟的幅度大于黄淮平原夏玉米各物候期推迟的幅度。玉米物候期的变化改变了相应生长阶段的长度,中国春/夏/春夏播玉米营养生长期（播种期—抽雄期）呈现不同程度的缩短趋势,而对应的生殖生长期（抽雄期—成熟期）呈现不同程度的延长趋势;春玉米生育期（播种期—成熟期）延长,夏/春夏播玉米生育期缩短。     

中国东北耕地物候期对气候变化的响应(英文)

We investigated the responses of cropland phenophases to changes of agricultural thermal conditions in Northeast China using the SPOT-VGT Normalized Difference Vegetation Index (NDVI) ten-day-composed time-series data, observed crop phenophases and the climate data collected from 1990 to 2010. First, the phenological parameters, such as the dates of onset-of-growth, peak-of-growth and end-of-growth as well as the length of the growing season, were extracted from the smoothed NVDI time-series dataset and showed an obvious correlation with the observed crop phenophases, including the stages of seedling, heading, maturity and the length of the growth period. Secondly, the spatio-temporal trends of the major thermal conditions (the first date of ≥10℃, the first frost date, the length of the temperature-allowing growth period and the accumulated temperature (AT) of ≥10℃) in Northeast China were illustrated and analyzed over the past 20 years. Thirdly, we focused on the responses of cropland phenophases to the thermal conditions changes. The results showed that the onset-of-growth date had an obvious positive correlation with the first date of ≥10℃ (P < 0.01), especially in the northern part of the Songnen Plain, the eastern part of the Sanjiang Plain and the middle and eastern parts of Jilin Province. For the extracted length of growing season and the observed growth period, notable correlations were found in almost same regions (P < 0.05). However, there was no obvious correlation between the end-of-growth date and the first frost date in the study area. Opposite correlations were observed between the length of the growing season and the AT of ≥10℃. In the northern part of the Songnen Plain, the eastern part of the Sanjiang Plain and the middle part of Jilin and Liaoning Provinces, the positive correlation coefficients were higher than the critical value of 0.05, whereas the negative correlation coefficients reached a level of 0.55 (P < 0.05) in the middle and southern parts of Heilongjiang Province and some parts of the Sanjiang Plain. This finding indicated that the crop growth periods were shortened because of the elevated temperature; in contrast, the extended growth period usually meant a crop transformation from early- or middle-maturing varieties into middle or late ones.     

近50年气候变化背景下中国西部冰川面积状况分析(英文)

Based on the glacier area variation records in the typical regions of China moni-tored by remote sensing, as well as the meteorological data of air temperature and precipitation from 139 stations and the 0℃ isotherm height from 28 stations, the glacier area shrinkage in China and its climatic background in the past half century was discussed. The initial glacier area calculated in this study was 23,982 km2 in the 1960s/1970s, but the present area was only 21,893 km2 in the 2000s. The area-weighted shrinking rate of glacier was 10.1%, and the interpolated annual percentage of area changes (APAC) of glacier was 0.3% a-1 since 1960. The high APAC was found at the Ili River Basin and the Junggar Interior Basin around the Tianshan Mountains, the Ob River Basin around the Altay Mountains, the Hexi Interior Basin around the Qilian Mountains, etc. The retreat of glacier was affected by the climatic background, and the influence on glacier of the slight-increased precipitation was counteracted by the significant warming in summer.     

1961-2008年中国西南地区极端气候变化幅度的海拔效应(英文)

A total of 12 indices of temperature extremes and 11 indices of precipitation ex-tremes at 111 stations in southwestern China at altitudes of 285-4700 m were examined for the period 1961-2008. Significant correlations of temperature extremes and elevation in-cluded the trends of diurnal temperature range, frost days, ice days, cold night frequency and cold day frequency. Regional trends of growing season length, warm night frequency, coldest night and warmest night displayed a statistically significant positive correlation with altitude. These characteristics indicated the obvious warming with altitude. For precipitation extreme indices, only the trends of consecutive dry days, consecutive wet days, wet day precipitation and the number of heavy precipitation days had significant correlations with increasing alti-tude owing to the complex influence of atmospheric circulation. It also indicated the increased precipitation mainly at higher altitude areas, whereas the increase of extreme precipitation events mainly at lowers altitude. In addition, the clearly local influences are also crucial on climate extremes. The analysis revealed an enhanced sensitivity of climate extremes to ele-vation in southwestern China in the context of recent warming.     

近30年中国东北地区玉米种植体系的时空动态分析(英文)

Understanding crop patterns and their changes on regional scale is a critical requirement for projecting agro-ecosystem dynamics. However, tools and methods for mapping the distribution of crop area and yield are still lacking. Based on the cross-entropy theory, a spatial production allocation model(SPAM) has been developed for presenting spatio-temporal dynamics of maize cropping system in Northeast China during 1980–2010. The simulated results indicated that(1) maize sown area expanded northwards to 48°N before 2000, after that the increased sown area mainly occurred in the central and southern parts of Northeast China. Meanwhile, maize also expanded eastwards to 127°E and lower elevation(less than 100 m) as well as higher elevation(mainly distributed between 200 m and 350 m);(2) maize yield has been greatly promoted for most planted area of Northeast China, especially in the planted zone between 42°N and 48°N, while the yield increase was relatively homogeneous without obvious longitudinal variations for whole region;(3) maize planting density increased gradually to a moderately high level over the investigated period, which reflected the trend of aggregation of maize cultivation driven by market demand.     

1990年以来中国小麦农业气象灾害时空变化特征(英文)

Agro-meteorological disasters(AMD) have become more frequent with climate warming. In this study, the temporal and spatial changes in the occurrence frequency of major meteorological disasters on wheat production were firstly explored by analyzing the observed records at national agro-meteorological stations(AMS) of China from 1991 to 2009. Furthermore, impact of climate change on AMD was discussed by comparing the warmer decade(2000–2009) with another decade(1991–2000). It was found that drought was the most frequent disaster during the last two decades, with a highest proportion of 79%. And the frequency of AMD increased significantly with climate change. Specifically, the main disasters occurred more frequently in the reproductive period than in the vegetative period. Besides, the spatial changes in the AMD frequency were characterized by region-specific. For example, the wheat cultivation areas located on the Loess Plateau and the middle-lower reaches of the Yellow River suffered mainly from drought. All these results were strongly linked to climate change in China. Therefore, sound adaptation options should be taken based on the latest changes of AMD under global warming to reduce agricultural damages.     

2001-2010年中国地表比辐射率的时空变化(英文)

Land surface emissivity is one of the important parameters in temperature inversion from thermal infrared remote sensing. Using MOD11C3 of Terra-MODIS L3 level products, spatio-temporal data sets of land surface emissivity in China for 10 years from 2001 to 2010 are obtained. The results show that the land surface emissivity in the northwest desert region is the lowest in China, with little seasonal variations. In contrast, there are significant seasonal variations in land surface emissivity in northeast China and northern Xinjiang, the Qing-hai-Tibet Plateau, the Yangtze River Valley and the eastern and southern China. In winter, the land surface emissivity in the northeast China and northern Xinjiang is relatively high. The land surface emissivity of the Qinghai-Tibet Plateau region is maintained at low value from November to March, while it becomes higher in other months. The land surface emissivity of the Yangtze River Valley, eastern and southern China, and Sichuan Basin varies from July to October, and peaks in August. Land surface emissivity values could be divided into five levels: low emissivity (0.6163-0.9638), moderate-low emissivity (0.9639-0.9709), moderate emis-sivity (0.9710-0.9724), moderate-high emissivity (0.9725-0.9738), and high emissivity (0.9739-0.9999). The percentages of areas with low emissivity, moderate-low emissivity and moderate emissivity are, respectively, about 20%, 10% and 20%. The moderate-high emis-sivity region makes up 40%-50% of China’s land surface area. The inter-annual variation of moderate-high emissivity region is also very clear, with two peaks (in spring and autumn) and two troughs (in summer and winter). The inter-annual variation of the high emissivity region is very significant, with a peak in winter (10%), while only 1% or 2% in other seasons. There is a clear association between the spatio-temporal distribution of China’s land surface emissivity and temperature: the higher the emissivity, the lower the temperature, and vice versa. Emis-sivity is an inherent property of any object, but the precise value of its emissivity depends very much on its surrounding environmental factors.     

1981-2009河南玉米物候对气候变化的响应和敏感度分析（英文）

With the global warming, crop phenological shifts in responses to climate change have become a hot research topic. Based on the long-term observed agro-meteorological phenological data(1981–2009) and meteorological data, we quantitatively analyzed temporal and spatial shifts in maize phenology and their sensitivities to key climate factors change using climate tendency rate and sensitivity analysis methods. Results indicated that the sowing date was significantly delayed and the delay tendency rate was 9.0 d·10a-1. But the stages from emergence to maturity occurred earlier(0.1 d·10a-1θ1.7 d·10a-1, θ is the change slope of maize phenology). The length of vegetative period(VPL)(from emergence to tasseling) was shortened by 0.9 d·10a-1, while the length of generative period(GPL)(from tasseling to maturity) was lengthened by 1.7 d·10a-1. The growing season length(GSL)(from emergence to maturity) was lengthened by 0.4 d·10a-1. Correlation analysis indicated that maize phenology was significantly correlated with average temperature, precipitation, sunshine duration and growing degree days(GDD)(p0.01). Average temperature had significant negative correlation relationship, while precipitation, sunshine duration and growing degree days had significant positive correlations with maize phenology. Sensitivity analysis indicated that maize phenology showed different responses to variations in key climate factors, especially at different sites. The conclusions of this research could provide scientific supports for agricultural adaptation to climate change to address the global food security issue.     

三江源地区1961-2010年降水时空变化(英文)

Based on a monthly dataset of precipitation time series (1961-2010) from 12 meteorological stations across the Three-River Headwater Region (THRHR) of Qinghai Province, China, the spatio-temporal variation and abrupt change analysis of precipitation were examined 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 precipitation 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 precipitation 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 precipitation were primary in the mid-to late 1970s. This research would be helpful for further understanding the trends and periodicity of precipitation and for watershed-based water resource management in the THRHR.     

1961-2010年三江源地区气温变化与突变分析(英文)

In this study, a monthly dataset of temperature time series (1961-2010) from 12 meteorological stations across the Three-River Headwater Region of Qinghai Province (THRHR) was used to analyze the climate change. The temperature variation and abrupt change analysis were examined by using moving average, linear regression, Spline interpo-lation, Mann-Kendall test and so on. Some important conclusions were obtained from this research, which mainly contained four aspects as follows. (1) There were several cold and warm fluctuations for the annual and seasonal average temperature in the THRHR and its three sub-headwater regions, but the temperature in these regions all had an obviously rising trend at the statistical significance level, especially after 2001. The spring, summer, autumn and annual average temperature increased evidently after the 1990s, and the winter average temperature exhibited an obvious upward trend after entering the 21st century. Except the standard value of spring temperature, the annual and seasonal temperature standard value in the THRHR and its three sub-headwater regions increased gradually, and the upward trend for the standard value of winter average temperature indicated significantly. (2) The tendency rate of annual average temperature in the THRHR was 0.36℃10a?1, while the tendency rates in the Yellow River Headwater Region (YERHR), Lancangjiang River Headwater Region (LARHR) and Yangtze River Headwater Region (YARHR) were 0.37℃10a?1, 0.37℃10a?1 and 0.34℃10a?1 respectively. The temperature increased significantly in the south of Yushu County and the north of Nangqian County. The rising trends of temperature in winter and autumn were higher than the upward trends in spring and summer. (3) The abrupt changes of annual, summer, autumn and winter average temperature were found in the THRHR, LARHR and YARHR, and were detected for the summer and autumn average temperature in the YERHR. The abrupt changes of annual and summer average temperatures were mainly in the late 1990s, while the abrupt changes of autumn and winter average temperatures ap-peared primarily in the early 1990s and the early 21st century respectively. (4) With the global warming, the diversities of altitude and underlying surface in different parts of the Tibetan Plateau were possibly the main reasons for the high increasing rate of temperature in the THRHR.     

Spatiotemporal differentiation of changes in maize phenology in China from 1981 to 2010

Journal of Geographical Sciences - Spatio-temporal changes in the differentiation characteristics of eight consecutive phenological periods and their corresponding lengths were quantitatively...     

Reponses and sensitivities of maize phenology to climate change from 1981 to 2009 in Henan Province,China

With the global warming, crop phenological shifts in responses to climate change have become a hot research topic. Based on the long-term observed agro-meteorological phenological data (1981–2009) and meteorological data, we quantitatively analyzed temporal and spatial shifts in maize phenology and their sensitivities to key climate factors change using climate tendency rate and sensitivity analysis methods. Results indicated that the sowing date was significantly delayed and the delay tendency rate was 9.0 d·10a^-1. But the stages from emergence to maturity occurred earlier (0.1 d·10a^-1<θ<1.7 d·10a^-1, θ is the change slope of maize phenology). The length of vegetative period (VPL) (from emergence to tasseling) was shortened by 0.9 d·10a^-1, while the length of generative period (GPL) (from tasseling to maturity) was lengthened by 1.7 d·10a^-1. The growing season length (GSL) (from emergence to maturity) was lengthened by 0.4 d·10a^-1. Correlation analysis indicated that maize phenology was significantly correlated with average temperature, precipitation, sunshine duration and growing degree days (GDD) (p<0.01). Average temperature had significant negative correlation relationship, while precipitation, sunshine duration and growing degree days had significant positive correlations with maize phenology. Sensitivity analysis indicated that maize phenology showed different responses to variations in key climate factors, especially at different sites. The conclusions of this research could provide scientific supports for agricultural adaptation to climate change to address the global food security issue.     

2000—2019年赛里木湖湖冰物候特征变化

基于MODIS影像、中国湖泊数据集及气象数据,综合分析了2000—2019年赛里木湖湖冰物候特征变化及影响因素.结果表明:(1)赛里木湖湖冰开始冻结和开始消融日期平均出现在11月2日和4月26日,湖冰完全封冻和完全消融日期平均出现在1月18日和5月17日,湖冰完全封冻期和湖冰冰期平均为99 d和196 d.(2)近20...     

The dynamic monitoring of corn planting area distribution in response to climate change from 2001 to 2010: a case study of Northeast China

Climate change has effects on crop distribution and production due to altering precipitation and temperature patterns. Northeast China is one of the most sensitive areas affected by climate change. In this study, MODIS09A1 data from MODerate resolution Imaging Spectroradiometer incorporated with phenology data from 21 agro-meteorological stations were used to monitor the dynamic change of corn distribution in response to climate change in the Northeast China for the decade of 2001 and 2010. Corn area estimates and statistics had the same change trend from 2001 to 2010 showing an annual increase. Furthermore, in order to analyse the gravity centre variations of the corn distribution, regions were chosen with corn planting areas of more than 500 km². Results showed that the main corn planting area had a trend to move towards high latitude and high longitude in response to climate change. It moved towards north about .58 degrees and east about .21 degrees between 2001 and 2010. The analysis of temperature and precipitation patterns revealed the same trend as the corn planting area. However, the corn area change was more sensitive to temperature than precipitation in Northeast China.     

基于作物空间分配模型的东北三省春玉米时空分布特征

利用1980-2010 年东北三省分县玉米播种面积与产量统计、耕地分布、农业灌溉分布以及作物适宜性分布等多源数据,结合基于交叉信息熵原理的作物空间分配模型（Spatial Production Allocation Model,SPAM）,在5'×5'的像元尺度模拟了春玉米种植面积与产量的时空分布,并重点分析了两者在纬向、经向,以及高程上的时空变化规律。结果显示：（1）玉米种植面积在2000 年前向北扩展至北纬44°~48°间,2000 年后在中南部出现大规模发展（北纬42°~44°）,并进一步向东扩展至东经123°~127°间,同时还表现为向低海拔（高程100 m以下）和较高海拔（高程200~350 m）扩展的态势;（2）单产在纬向上的增加区主要集中在北纬42°~48°,经向上的单产增加则相对均匀,高程上单产提升区主要集中在海拔350 m以下。（3）像元内玉米种植比例整体上由中低种植比例为主逐步演变为中高比例占据主体,并且中高种植比例像元对应的玉米单产水平整体上较高,反映了市场经济驱动下的玉米种植集聚化和规模化的发展趋势。     

近50年北京树木物候对气候变化的响应

采用统计学方法探讨了北京地区1963~1988年间20种树木芽萌动期及1950~2000年间4种树木开花期的变化及其对气温变化的响应情况。结果表明,北京树木芽萌动的早晚主要受冬季气温的影响,冬季及秋末气温的升高使春芽萌动有提前的效应。萌芽早的树木萌动期长,萌芽晚的树木萌动期短,前者对温度的变化反应更敏感,且前者的萌动期长度随着萌动期间(主要在早春)气温的升高而缩短,后者的萌动期长度随着初冬、秋末平均最低气温的升高而延长。始花前2~9旬,特别是前5旬(主要是3~4两个月),气温对始花期影响最显著,该时段内始花期对气温的变化反应最敏感。北京春温升高开花期提前,春温每升高1℃,开花期平均提前3·6天。春季树木开花物候与春季气温的年际、年代间的波动基本对应,但波动幅度不一致。     

东西伯利亚苔原—泰加林过渡带植被遥感物候时空特征及其对气温变化的响应

物候变化是气候变化的重要指示器,通过对植被物候时空变化的研究可以为进一步分析全球气候变化提供依据。基于2000—2017年MODIS-NDVI时间序列数据,利用不对称高斯函数和动态阈值法,提取、分析了东西伯利亚苔原—泰加林过渡带植被生长季起始期（SOS）、结束期（EOS）、中期（MOS）和长度（LOS）4种植被遥感物候参数的时空变化格局。同时结合同期CRU（Climate Research Unit）气温观测数据,分析了4种物候参数对气温变化的响应关系。结果表明：遥感物候参数可以直接、有效地反映气温的变化：研究区64°N以南区域4—5月气温升高,对应区域SOS提前5~15 d;64°N~72°N之间5—6月气温升高,对应区域SOS提前10~25 d;最北端北冰洋沿岸6月气温升高幅度较小且7月气温降低,对应区域SOS推后15~25 d;西北部8月、西南部9月气温降低,对应地区EOS提前15~30 d;67°N以南区域9—10月气温升高,对应区域EOS推后5~30 d;EOS的变化对气温变化较SOS更为敏感,较小的气温波动即引起EOS较大的变动;研究区内植被生长季整体呈前移趋势,且西北部LOS缩短,中部、南部LOS延长。     

Spatiotemporal changes of land desertification sensitivity in northwest China from 2000 to 2017

Sensitivity assessment is useful for monitoring land desertification.Research into how to prevent and control desertification is also important.In the arid region of northwest China,desertification is becoming worse and is a serious problem that affects local sustain-able development.Based on remote-sensing and geographic information system technology,this study establishes a"soil-terrain-hydrology-climate-vegetation"desertification sensitivity comprehensive evaluation system to reflect the spatiotemporal changes of land desertifica-tion,and proposes a spatial distance model to calculate a desertification sensitivity index.The spatiotemporal change characteristics of land desertification sensitivity in northwest China are quantitatively assessed from 2000 to 2017.Moreover,the main driving factors are ana-lyzed using the geographical detector method.The results show the following.(1)Terrain,soil,climate,vegetation and hydrology affect and restrict each other,and constitute the back-ground conditions of the distributions and changes of sensitivity to desertification in northwest China.(2)Desertification sensitivity generally displays a low distribution characteristic on the periphery of the area and a high one in the interior.The low-sensitivity regions are mainly in the five major mountain ranges(Altai Mountains,Tianshan Mountains,Kunlun Mountains,Altun Mountains and Qilian Mountains),while the high-sensitivity regions are mainly in re-gions such as the Junggar Basin,the Tarim Basin and the Inner Mongolia Plateau,as well as the Taklimakan Desert,Badain Jaran Desert and Tengger Desert.The spatial distribution of desertification sensitivity is obviously regional,and the high-and low-sensitivity regions have clear boundaries and a concentrated distribution.(3)With regard to spatiotemporal evolution,changes in desertification sensitivity since 2000 have been predominantly stable,and the overall sensitivity has displayed a slowly decreasing trend,indicating that potential desertifi-cation regions are decreasing annually and that some achievements have been made in the control of regional desertification. (4) Soil and climate play a direct role in the driving factors of desertification in northwest China, and these have been found to be the most important in-fluential factors. Vegetation is the most active and basic factor in changing the sensitivity. In addition, topography and hydrology play a role in restricting desertification changes. So-cio-economic factors are the most rapid factors affecting regional desertification sensitivity,and their impacts tend to be gradually increasing. In general, desertification has been effec-tively controlled in northwest China, and positive results have been achieved in such control.However, against the backdrop of intensified global climate change, increasingly prominent human activities and new normals of socio-economic development, the monitoring, assess-ment and control of desertification in China still have a long way to go.     

中国作物物候对气候变化的响应与适应研究进展

以气候变暖为主要特征的气候变化对作物物候产生了重要的影响,通常气温升高会导致作物生长速度加快,生育期缩短,从而造成作物产量下降,不利于农业发展。同时,作物物候变化可以直接或间接反映气候变化情况,对于气候变化具有重要的指示意义。作物物候的研究对于农业气象灾害的预防、农业生产管理水平的进步以及农业产量提高都极为关键。随着全球地表气温的持续升高,作物物候相关研究也越来越引起科学家的关注。论文结合作物物候的主要研究方法,综述了中国近几十年来小麦、玉米、水稻以及棉花、大豆等主要农作物的生育期变化特征以及主要的驱动因子,得到以下主要结论：①在研究方法上,统计分析方法应用最为普遍,其他几种方法都需要与统计分析方法相结合使用。另外,作物机理模型模拟方法易于操作、可行性强,在物候研究中应用也比较多。遥感反演方法对作物生育期的特征规律要求较高,一般主要关注作物返青期。②整体上,小麦全生育期主要呈缩短趋势,而玉米和水稻全生育期以延长趋势为主。③作物物候变化的驱动因子主要是气候变化和农业管理措施改变,其中,气候变化是主导驱动因子,对作物物候变化起决定作用,而调整农业管理措施,在一定程度上抵消气候变化对作物生育期的不利影响。作物物候对气候变化的响应和适应研究可以为农业生产适应气候变化提供重要的理论依据和对策。