Forest phenological patterns of Northeast China inferred from MODIS data

The role of remote sensing in phenological studies is increasingly regarded as a key to understand large area seasonal phenomena. This paper describes the application of Moderate Resolution Imaging Spectroradiometer (MODIS) time series data for forest phenological patterns. The forest phenological phase of Northeast China (NE China) and its spatial characteristics were inferred using 1-km 10-day MODIS normalized difference vegetation index (NDVI) datasets of 2002. The threshold-based method was used to estimate three key forest phenological variables, which are the start of growing season (SOS), the end of growing season (EOS) and growing season length (GSL). Then the spatial patterns of forest phenological variables of NE China were mapped and analyzed. The derived phenological variables were validated by the field observed data from published papers in the same study area. Results indicate that forest phenological phase from MODIS data is comparable with the observed data. As the derived forest phenological pattern is related to forest type distribution, it is helpful to discriminate between forest types.

Impacts of Polar Vortex,NPO,and SST Configurations on Unusually Cool Summers in Northeast China.Part I:Analysis and Diagnosis

This study unveils the evolution of two major early signals in the North Pacific atmosphere-ocean system that heralded abnormal high-pressure blockings and cold-vortex activities across Northeast China, based on an analysis of the configurations of major modes including the polar vortex, the North Pacific Oscillation （NPO）, and SST in the preceding winter and spring and atmospheric low-frequency disturbances in Northeast China. We analyzed these aspects to understand the atmosphere ocean physical coupling processes characterized by the two early signals, and here we explain the possible mechanisms through which dipole circulation anomalies affect the summer low-temperature processes in Northeast China. We further analyzed the interdecadal variation background and associated physical processes of the two early signals.

Numerical Experiments on the Impact of Spring North Pacific SSTA on NPO and Unusually Cool Summers in Northeast China

A set of numerical experiments designed to analyze the oceanic forcing in spring show that the combined forcing of cold （warm） El Ni（n）o （La Ni（n）a） phases in the Ni（n）o4 region and sea surface temperature anomalies （SSTA） in the westerly drifts region would result in abnormally enhanced NorthEast Cold Vortex （NECV） activities in early summer.In spring,the central equatorial Pacific El Ni（n）o phase and westerly drift SSTA forcing would lead to the retreat of non-adiabatic waves,inducing elliptic low-frequency anomalies of tropical air flows.This would enhance the anomalous cyclone-anticyclonecyclone-anticyclone low-frequency wave train that propagates from the tropics to the extratropics and further to the mid-high latitudes,constituting a major physical mechanism that contributes to the early summer circulation anomalies in the subtropics and in the North Pacific mid-high latitudes.The central equatorial Pacific La Ni（n）a forcing in the spring would,on the one hand,induce teleconnection anomalies of high pressure from the Sea of Okhotsk to the Sea of Japan in early summer,and on the other hand indirectly trigger a positive low-frequency East Asia-Pacific teleconnection （EAP） wave train in the lower troposphere.

Use of Intensity Analysis to Measure Land Use Changes from 1932 to 2005 in Zhenlai County, Northeast China

Analyzing spatiotemporal dynamics of land use and land cover over time is widely recognized as important to better understand and provide solutions for social, economic, and environmental problems, especially in ecologically fragile region. In this paper, a case study was taken in Zhenlai County, which is a part of farming-pastoral ecotone of Northeast China. This study seeks to use multi-temporal satellite images and other data from various sources to analyze spatiotemporal changes from 1932 to 2005, and applied a quantitative methodology named intensity analysis in the time scale of decades at three levels: time interval, category, and transition. The findings of the case study are as follows: 1) the interval level of intensity analysis revealed that the annual rate of overall change was relatively fast in 1932–1954 and 1954–1976 time intervals. 2) The category level showed that arable land experienced less intensively gains and losses if the overall change was to have been distributed uniformly across the landscape while the gains and losses of forest land, grassland, water, settlement, wetland and other unused land were not consistent and stationary across the four time intervals. 3) The transition level illustrated that arable land expanded at the expense of grassland before 2000 while it gained intensively from wetland from 2000 to 2005. Settlement targets arable land and avoids grassland, water, wetland and other unused land. Besides, the loss of grassland was intensively targeted by arable land, forest land and wetland in the study period while the loss of wetland was targeted by water except for the time interval of 1976–2000. 4) During the early reclamation period, land use change of the study area was mainly affected by the policy, institutional and political factors, followed by the natural disasters.

The Interannual Variation in Monthly Temperature over Northeast China during Summer

The interannual variations of summer surface air temperature over Northeast China （NEC） were investigated through a month-to-month analysis from May to August. The results suggested that the warmer temperature over NEC is related to a local positive 500-hPa geopotential height anomaly for all four months. However, the teleconnection patterns of atmospheric circulation anomalies associated with the monthly surface air temperature over NEC behave as a distinguished subseasonal variation, although the local positive height anomaly is common from month to month. In May and June, the teleconnection pattern is characterized by a wave train in the upper and middle troposphere from the Indian Peninsula to NEC. This wave train is stronger in June than in May, possibly due to the positive feedback between the wave train and the South Asian rainfall anomaly in June, when the South Asian summer monsoon has been established. In July and August, however, the teleconnection pattern associated with the NEC temperature anomalies is characterized by an East Asia/Pacific （EAP） or Pacific/Japan （PJ） pattern, with the existence of precipitation anomalies over the Philippine Sea and the South China Sea. This pattern is much clearer in July corresponding to the stronger convection over the Philippine Sea compared to that in August.

Sandy desertification trend in western Northeast China Plain in the past 10 years

The west sandy land of the Northeast China Plain is located in the eastern huge sandy belt of mid-latitude in Eurasia and the eastern fringe of desertified land with best bio-climatic conditions in China. With rapid economic development, the deterioration of eco-environment has occurred and the desertification becomes very obvious. The first part of this paper studies the regional differences of landscape patterns and explores the regional differences of desertification. The second part aims to reveal the dynamics of desertification in the 1990s by using NOAA/AVHRR data and thematic data in GIS database. This work lays a scientific basis for the rehabilitation and development of the sandy lands.

The Status Quo of Chinese Agro-products Logistics and the Establishment of the Third-Party Logistics Mode

The status quo of Chinese agro-products logistics is analyzed from the following five aspects:the circulation mode,exchange mode,storage and transportation situation,food security.The following problems in Chinese agro-products logistics are pointed out,including excessive circulation sections,bad time efficiency,single payment,slow circulation,backward information processing,obvious bullwhip effect,low logistics efficiency,low logistics technology,inadequate professional equipments,low standardization degree,organized operation mode and low degree of scale.The third-party logistics mode of agro-products is analyzed and the advantages of the mode are analyzed as well.Firstly,establishing information network through integrating circulation section to accelerate the circulation of agro-products;secondly,making the operation norms by providing professional equipments to secure the quality of agricultural products;thirdly,improving the core competitiveness of the whole logistics chain by intensifying specialized work division in each section of the supply chain;fourthly,through forming scale economy to reduce logistics costs and increase the diversity of products;fifthly,through signing contracts to clarify duties and responsibilities and materialize the profit integration of the supply chain.The measures for establishing the third-party logistics of agro-products are put forward,including establish the awareness and concept of socialized logistics services;intensify the support on the third-party logistics enterprises of agro-products;lay stress on the cultivation of logistics talents of agro-products;and vigorously apply the modern marketing means.

A Methodology Framework for Regional Land-use Change Studies based on Landsat TM images: A Case Study in Northeast China

Land-use change is an important aspect of global environment change. It is, in a sense, the direct result of human activities influencing our physical environment. This paper analyzed the land-use change in Northeast China during 1985-2000 based on Landsat TM images. It divides Northeast China into five land-use zones based on the dynamic degree model of land-use: woodland/grassland-arable land conversion zone, dry land-paddy field conversion zone; urban expansion zone, interlocked zone of farming and pasturing and reclamation and abandon zone. The findings include the obvious increase of cropland area, paddy field and dry land increased by 75 and 276 thousand hm2 respectively; urban areas expanded rapidly, areas of town and rural residence increased by 76.8 thousand hm2; areas of forests and grassland decreased sharply with the amounts of 1399 and 1521 thousand hm2 respectively; areas of water body and unused land increased by 148 and 514 thousand hm2 respectively. This paper also discusses the

“双碳”目标下东北黑土区耕地利用生态效率时空格局与演变趋势

[目的]探究东北黑土区耕地利用生态效率的时空格局和演变趋势,将碳源与碳汇融入耕地利用过程,这对于实现黑土减排增效和“双碳”目标至关重要。[方法]基于超效率SBM模型、核密度估计、探索性空间数据分析和空间插值工具等方法,系统考察了2006—2020年东北黑土区耕地利用生态效率的时空特征与演进规律。[结果]黑土区耕地利用生态效率历经波动上升、显著下降和迅速回升3个阶段,总体处于较高发展水平,北部边缘城市的效率值明显高于中南部地区,基期和末期区间两极分化局势尤为显著,整体发展严重失衡;黑土区耕地利用生态效率全局空间相关特性并不明显,大致呈现“边缘—中心”空间扩散格局,由南北两端高值集聚向内及四周递减,而后形成多个块状高值区和低值分布带,规模集聚优势未能得到充分发挥;多数城市均存在不同程度的投入与产出冗余,劳动力和化肥冗余问题较为严重,碳排放冗余是造成黑土区耕地利用生态效率损失的普遍因素。[结论]优化要素配置和污染减排治理成为黑土利用重点改善方向,也是提升黑土区耕地利用生态效率的关键路径。

Vegetation pattern of Northeast China during the special periods since the Last Glacial Maximum

Since the Last Glacial Maximum(LGM), the global climate has experienced several stages, such as cold and warming events, which provide an ideal model for evaluating climate change in the future. Based on the pollen records in Northeast(NE) China, the vegetation pattern during special periods since the LGM was reconstructed in this work. During the LGM(approximately 18,000 cal yr BP), the steppes expanded rapidly in NE China, and a cold-dry meadow-steppe developed on the Songnen Plain. The Liaohe Plain and the Hulun Buir Plateau were occupied by a steppe-desert, with forest-steppe vegetation grown in the central and southern plains;there were cold-dry coniferous forests and mixed conifer-broadleaf forests in mountainous areas. In the early Holocene(10,000–9,000 cal yr BP), Changbai mountain(CBM) forests thrived in the eastern hilly area and the Sanjiang Plain, while the central region was dominated by steppes, and warm-temperate broadleaf forests developed northward. During the Holocene warm period(approximately 6,000 cal yr BP), CBM forests and cold-temperate coniferous forests developed in the north, while spruce-fir forests developed in the eastern Xiao Hinggan Mountains and the Sanjiang Plain. The distribution centre of deciduous broadleaf forests migrated to the south of the Changbai Mountains and the Liaodong Peninsula. The isolated woodlands increased on the Songnen Plain and the meadow-steppes expanded to the Liaohe Plain. Therefore, the increase in temperature leads to the increase of monsoon precipitation in NE China, which is beneficial to the development of warm-temperate forest vegetation. The increase of summer monsoons and precipitation caused by climate warming may be the main reason for the improved plant load.

东北女青年参数化鞋楦定制研究

本文基于东北女青年的脚型特征及规律,构建了一种特征点的参数化建模方法。采用三维足部扫描仪提取东北女青年18个足部特征参数,分析其脚型特征及规律,利用逆向工程技术确定286个特征点。根据脚楦关系,调整东北女青年鞋楦尺寸参数,以脚长和基宽为自变量,建立其与特征点长度方向、宽度方向、高度方向的参数关系,以构建东北女青年参数化鞋楦模型。采用该方法获得的鞋楦模型数字化程度高,便于鞋楦参数调整,对于个性化鞋楦定制具有重要意义。

Spatio-temporal dynamics of maize cropping system in Northeast China between 1980 and 2010 by using spatial production allocation model

Understanding crop patterns and their changes on regional scale is a critical re- quirement 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 spa- tio-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, espe- cially 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.

基于CA-Markov模型的大凌河流域土地利用变化与模拟预测研究

基于大凌河流域2000、2010和2020年3期土地利用数据,采用土地利用动态度、土地利用程度、土地利用转移矩阵等方法分析过去20年来研究区土地利用变化规律,并基于元胞自动机-马尔可夫(CA-Markov)模型模拟预测研究区2030年土地利用格局.结果表明:2000—2020年大凌河流域土地利用以耕地和草地为主,二者占比超过80%.近20年间,研究区内林地、草地和建设用地面积不断增加,耕地面积持续减少,且减少的速度在加快,前后两个10年分别减少了132.85和1360.13 km^(2).2000—2020年间,土地综合利用动态度由43.53%降低为10.36%,处于降低趋势.建设用地动态度由0.11%增加至4.99%,湿地动态度由86.32%变为-7.22%,土地利用程度综合指数由262.53变为259.91,表明大凌河流域近20年土地处于衰退期.基于CA-Markov模型预测大凌河流域2030年土地利用格局,模拟精度Kappa系数为0.8835.预测结果表明,2030年,大凌河流域耕地面积将进一步减少1699.92 km^(2),主要变为草地、建设用地和林地.

A Comparative Analysis on Urbanization of Former Industrial Bases in Northeast China

The concentrated urbanization with the priority given to large cities and the balanced urbanization with the emphasis laid on small towns development are the two major urbanization patterns nowadays.The paper analyzes the urbanization pattern of the Great Lakes Industrial Area of US and the Ruhr Industrial Area of Germany,and compares it with the urbanization pattern of the former industrial base in Northeast China,which indicates that the development of the former industrial base is in a dilemma between the choices of these two urbanization patterns.In consequence,the paper discusses the choice of urbanization pattern of the former industrial base from the perspective of regional and spatial distinctions,as well as carrying out a countermeasure study on the urbanization patterns of different areas.

东三省区域物流效率测算研究——基于DEA-Malmquist

选取2011-2020年东北地区三个省份的面板数据,运用DEA-Malmquist指数模型,进行静态层面与动态层面的分析,进而得出相关结论,并提出提升物流效率的建议。实证结果表明:观测期内,东三省地区整体物流综合效率较高,其中吉林省居于首位,东三省全要素生产率十年期内平均下降1.7%,只有辽宁省呈现增长趋势,制约其余两个省份上升的主要原因是技术效率指标的下降。东三省地区应重视物流技术的创新与提高,加大省市间的协同发展,以谋求物流规模效益的最大化,同时政府应加强调控,因地制宜出台有关政策,发展特色物流、绿色物流。

交通发展格局演变的动力机制分析——以东北地区为例

理论认识交通发展格局演变特征,综合分析交通发展格局演变动力机制,以东北地区为例,探究东北地区交通发展格局演变特征及其内在动力机制。基于时空演化视角,交通发展格局空间形态依次表现为线段状、树枝状和网络状。其内在机制从空间维度看,表现为交通发展的区域根植性和地方“嵌入”;从时间维度看,表现为对交通发展需求牵引力和对交通发展供给推动力的均衡作用。进一步,以东北地区为例,运用逻辑分析与历史演化分析方法,分五个阶段探析了东北地区交通发展格局演变特征及其内在动力机制:①清末未建铁路时期服务于边疆稳定,推动交通驿站与驿道建设,交通发展呈点状分布;②俄日侵略时期服务于殖民扩张,主导推动中东铁路及支线铁路建设,交通发展呈网络化分布格局;③新中国建设时期服务于国家经济建设,交通发展呈网络密织分布格局;④改革开放时期服务于域内城市/城镇联系,交通发展呈网状升级分布态势;⑤振兴战略时期服务于高等级城市联系,交通发展呈网络极化态势。面向2035年,服务于共同富裕战略目标,发展数字交通,推动构建全国统一大市场发展格局是国家重要战略任务,东北地区交通建设布局则需借力交通“新基建”赋能县域城镇,加快县域城镇人口和经济高质量融入国际国内双循环市场空间,推动东北地区交通发展格局向网络极化分散方向转变。

多维视角下东北地区城市生态效率时空格局演变及影响因素

以东北三省34个地级市作为实证研究样本,运用Super-SBM模型、空间自相关、变异系数以及时空地理加权回归模型等方法,从功能区类型、依托资源类型、产业升级速率类型等视角对2008~2019年期间东北地区城市生态效率水平进行测度、空间格局特征刻画及影响因素作用分析。结果表明:研究期间生态效率总体呈小幅波动上升态势;三类功能区生态效率水平由2008年非生态功能区大于森林生态功能区大于湿地生态功能区转变为2019年湿地生态功能区大于森林生态功能区大于非生态功能区;五类资源型城市生态效率水平由2008年石油类大于非资源型大于森工类大于煤炭类大于金属类转变为2019年石油类大于森工类大于非资源型大于金属类大于煤炭类;三类产业升级速率城市生态效率水平始终为高速率大于低速率大于中等速率。研究期间生态效率高值区主要集中在北部黑龙江省和吉林省,低值区则集中在南部辽宁省;三个视角城市生态效率空间差异总体呈收敛态势。生态效率的影响因素作用强度依次为第二产业增加值占比大于外商投资企业产值/工业总产值大于人均GDP大于城镇化率大于环境规制指数大于科技支出占财政支出比重。森林生态功能区和非生态功能区的主导因素为第二产业增加值占比,湿地生态功能区的主导因素为城镇化率;煤炭类城市的主导因素为外商投资企业产值/工业总产值,其余资源类型城市的主导因素均为第二产业增加值占比;产业升级速率的低速率、中等速率、高速率类城市的主导因素均为第二产业增加值占比。最后根据不同视角提出针对性的建议。

推动东北亚和平发展的中国方案

推动东北亚和平发展,对于构建人类命运共同体具有重要意义,中国应勇担东北亚地区和平建设者与发展贡献者的新角色。对于影响东北亚和平发展的历史遗留问题及美国的肆意干涉,中国需要在历史中寻找经验,挖掘共有资源,发挥历史主动精神,引领东北亚地区各国化解历史遗留问题,并保持战略定力,摆脱美国的肆意干涉。中国还应立足于新发展格局的构建,为更好联通国内市场与国际市场,促进国内国际双循环,依托国内自贸试验区与中日地方合作发展示范区,共建“一带一路”等高水平对外开放平台,实现“引进来”与“走出去”,并通过RCEP拓宽合作领域,挖掘制度红利,推动东北亚地区经贸合作。

大食物观下东北主产区牛肉冷链物流优化发展研究

在大食物观背景下,随着城乡居民生活质量的不断提高,膳食结构不断优化,高涨的牛肉需求和集聚化生产特点带动牛肉冷链物流蓬勃发展的同时也带来了一系列挑战。文章以东北主产区为研究对象,梳理东北主产区肉牛生产现状及牛肉物流冷链特点,分析牛肉冷链物流存在的问题及其面临的挑战,并在此基础上,提出合理的优化建议。该研究对于推动牛肉冷链物流的高质量发展、保障牛肉稳定供给、满足消费者对优质农产品的需求、促进肉牛养殖产业健康可持续发展具有重要意义。

农作物分布格局动态变化的遥感监测——以东北三省为例

【目的】当前对涉及到耕地内部不同作物空间分布及其变化的研究较少。本文旨在探讨大尺度作物种植面积和分布格局遥感提取方法及景观生态学中景观格局指数在作物格局动态变化分析中的应用。【方法】基于2005年和2010年作物生育期内遥感影像全覆盖的MODIS-NDVI数据,利用RS、GIS技术,通过分析东北地区主要作物(水稻、玉米、大豆)的种植结构、物候历及NDVI曲线特征,建立不同作物面积遥感提取模型,提取大尺度农作物空间分布格局信息。同时,利用景观格局指数方法分析农作物格局动态变化特征和变化规律。【结果】与多年平均统计数据比较,基于MODIS遥感数据提取的作物面积信息,2005年和2010年平均精度达到了90%以上;5年间,东北地区主要作物种植结构发生了较大变化。其中大豆平均斑块面积减少,面积年动态度为-4.47%,水稻和玉米平均斑块面积均增加,且5年的变化幅度均超过20%。【结论】成本和收益是作物面积增加或减少的主要原因;用中等分辨率的遥感数据进行大尺度作物面积提取的方法是可行的;景观生态学中格局指数可以用来分析耕地内部作物格局的动态变化规律。