生生不息:乡土公共建筑的空间创新设计研究

湘西少数民族传统村落作为重要的“民族文化符号”,拥有特殊的历史、文化和社会价值。随着我国城镇化进程,少数民族传统村落出现“空心化”“老年化”“特色逐渐丧失”及“衰败”等现象,少数民族村寨人口流失、资源短缺、渠道不畅通、产业难以转型升级、乡村社区治理困难等问题,从乡土公共空间的研究入手,对少数民族传统村落的生态、生产、生活等进行分析调研,挖掘有价值的乡土公共空间的精神和语言,落实在少数民族传统村落的保护与发展、现代转化、风貌管控、制度与机制等空间创新设计,并以此落实湘西少数民族聚居区的乡村振兴战略。本文以湖南省张家界马头溪榨油坊的村民活动中心方案设计为例,寻求科学方法解决乡村公共空间创新设计问题。

华北地区1876-1879年旱灾研究文献综述

华北地区1876-1879年旱灾是历史灾害及极端干旱事件社会影响领域的研究热点之一。利用历史文献等资料,相关学者在旱灾气候变化背景与旱情、旱灾社会脆弱性、旱灾社会影响及旱灾社会响应等方面取得了大量研究成果。从研究阶段、研究方法、研究视角及主要结论等方面综述了相关研究成果。结果表明:现有文献全面涵盖不同视角与区域尺度,热点视角与研究区域反映了旱灾社会影响及响应的关键环节,以及区域不平衡的重要特征;现有文献采用史实陈述、综合分析、定量评价、空间分布及过程分析、对比分析及统计分析等方法,认为在极端干旱事件与社会脆弱性的相互作用下,旱灾社会影响被放大、赈灾成效受到制约,导致灾情极为惨重。未来研究需要进一步关注相关指标空间分布与过程的集成、插补、重建,旱灾社会影响与响应的区域差异与关联,极端干旱与人类社会相互作用与反馈机制的定量解释。

理解资源、环境与国家安全的三个维度

高中地理选择性必修3"资源、环境与国家安全",以资源、环境的影响为线索学习自然环境与人类社会的关系,落脚到资源安全和环境安全对国家安全的影响。根据课程标准的具体内容要求,理解"资源、环境与国家安全"包括三个维度,即(1)自然环境影响因子维度,影响国家安全的"资源"和"环境"问题;(2)人地相互作用过程维度,"资源"和"环境"影响国家安全的机制;(3)区域维度,"资源"和"环境"通过国家内部的尺度转换和国家间的区域关联影响国家安全。

基于聚落考古信息的中国北方农牧交错带东段历史耕地覆盖格网化重建

中国北方农牧交错带是半农半牧、时农时牧的地带,此类区域因其独特自然环境和社会经济发展过程,准确地重建耕地覆盖难度较大。采用能够指示农业活动时空位置的考古遗址信息重建历史耕地覆盖,是提高此类区域耕地覆盖重建结果可靠性的有效途径之一。本研究选择位于中国北方农牧交错带带宽最大的东段作为研究区,使用聚落考古信息与历史文献重建了辽、金、元、明4个时期5′×5′的耕地覆盖变化。结论如下:(1)从辽代至明代,研究区耕地面积总量减少了98.0%,元明时期的耕地显著少于辽金时期,表明该区发生了从半农半牧到牧业的根本转变。(2)辽代耕地分布范围最大,金代耕地分布范围有所缩小,辽金时期均呈现“插花式”的分布格局,元代耕地分布范围急剧缩减,至明代仅有零星耕地分布。(3)研究区耕地覆盖变化受气候变化和人文因素的双重影响。辽金时期,气候相对温暖湿润,统治者重视农业发展;元明时期,气候寒冷干燥,民族习惯以牧为主。基于聚落考古信息重建的历史时期耕地覆盖,不仅再现了该区域“插花式”的耕地分布格局,还刻画了该区由农转牧的土地利用变化过程。

Agriculture Development-induced Surface Albedo Changes and Climatic Implications Across Northeastern China

To improve the understandings on regional climatic effects of past human-induced land cover changes,the surface albedo changes caused by conversions from natural vegetation to cropland were estimated across northeastern China over the last 300 years,and its climatic effects were simulated by using the Weather Research and Forecasting (WRF) model.Essential natural vegetation records compiled from historical documents and regional optimal surface albedo dataset were used.The results show that the surface albedo decreased by 0.01-0.03 due to conversions from grassland to cropland in the Northeast China Plain and it increased by 0.005-0.015 due to conversions from forests to cropland in the surrounding mountains.As a consequence,in the Northeast China Plain,the surface net radiation increased by 4-8 W/m 2,2-5 W/m 2,and 1-3 W/m 2,and the climate was therefore warmed by 0.1℃-0.2℃、0.1℃-0.2℃、 0.1℃-0.3 ℃ in the spring,autumn and winter,respectively.In the surrounding mountain area,the net radiation decreased by less than 1.5 W/m 2,and the climate was therefore cooled too slight to be detected.In summer,effects of surface albedo changes on climate were closely associated with moisture dynamics,such as evapotranspiration and cloud,instead of being merely determined by surface radiation budget.The simulated summer climatic effects have large uncertainties.These findings demonstrate that surface albedo changes resulted in warming climate effects in the non-rainy seasons in Northeast China Plain through surface radiation processes while the climatic effects in summer could hardly be concluded so far.

The changing regional distribution of grain production in China in the 21st century

This paper examines the changing regional distribution of grain production in China. Based on the analysis of data from county statistics for the period 2000-2003, major differences in the main grain-output regions in China can be observed. The main grain-producing areas have shifted from the south to the north of China. New grain production regions have been also added to westem China since the late 1990s. The per capita grain consumption in one third of China＇s main grain-producing counties has fallen below 400 kg; most of these areas are located in southern China. In the new millennium, Northeast China, the central-south North China, and the add and semi-arid regions of Northwest China produced three quarters of the surplus grains. Most of these areas are located in regions susceptible to environmental change. The amount of grain production in these regions shows high fluctuations. It is argued here that fi.trther studies of recent environmental changes as well as a risk assessment of China＇s food security in main grain-output regions are needed.

Accuracy Comparison of Gridded Historical Cultivated Land Data in Jiangsu and Anhui Provinces

The spatial resolution of source data, the impact factor selection on the grid model and the size of the grid might be the main limitations of global land datasets applied on a regional scale. Quantitative studies of the impacts of rasterization on data accuracy can help improve data resolution and regional data accuracy. Through a case study of cropland data for Jiangsu and Anhui provinces in China, this research compared data accuracy with different data sources, rasterization methods, and grid sizes. First, we investigated the influence of different data sources on gridded data accuracy. The temporal trends of the History Database of the Global Environment(HYDE), Chinese Historical Cropland Data(CHCD), and Suwan Cropland Data(SWCD) datasets were more similar. However, different spatial resolutions of cropland source data in the CHCD and SWCD datasets revealed an average difference of 16.61% when provincial and county data were downscaled to a 10 × 10 km^2 grid for comparison. Second, the influence of selection of the potential arable land reclamation rate and temperature factors, as well as the different processing methods for water factors, on accuracy of gridded datasets was investigated. Applying the reclamation rate of potential cropland to grid-processing increased the diversity of spatial distribution but resulted in only a slightly greater standard deviation, which increased by 4.05. Temperature factors only produced relative disparities within 10% and absolute disparities within 2 km^2 over more than 90% of grid cells. For the different processing methods for water factors, the HYDE dataset distributed 70% more cropland in grid cells along riverbanks, at the abandoned Yellow River Estuary(located in Binhai County, Yancheng City, Jiangsu Province), and around Hongze Lake, than did the SWCD dataset. Finally, we explored the influence of different grid sizes. Absolute accuracy disparities by unit area for the year 2000 were within 0.1 km^2 at a 1 km^2 grid size, a 25% improvement over the 10 km^2 grid size. Compared to the outcomes of other similar studies, this demonstrates that some model hypotheses and grid-processing methods in international land datasets are truly incongruent with actual land reclamation processes, at least in China. Combining the model-based methods with historical empirical data may be a better way to improve the accuracy of regional scale datasets. Exploring methods for the above aspects improved the accuracy of historical cropland gridded datasets for finer regional scales.

Boundary Shift of Potential Suitable Agricultural Area in Farming-grazing Transitional Zone in Northeastern China under Background of Climate Change During 20th Century

Climate change affected the agricultural expansion and the formation of farming-grazing transitional patterns during historical periods.This study analyzed the possible range of the boundary shift of the potential suitable agriculture area in the farming-grazing transitional zone in the northeastern China during the 20th century.Based on modern weather data,1 km-resolution land cover data,historical climatic time series,and estimation by using similar historical climatic scenes,the following was concluded:1)The climate conditions of suitable agriculture areas in the farming-grazing transitional zone in the northeastern China between 1971 and 2000 required an average annual temperature above 1℃or≥0℃accumulated temperature above 2500℃–2700℃,and annual precipitation above 350 mm.2)The northern boundary of the potential suitable agriculture area during the relatively warmer period of 1890–1910was approximately located at the position of the 1961–2000 area.The northern boundary shifted back to the south by 75 km on average during the colder period of the earlier 20th century,whereas during the modern warm period of the 1990s,the area shifted north by 100km on average.3)The western and eastern boundaries of the suitable agriculture area during the heaviest drought periods between1920s and 1930s had shifted northeast by 250 km and 125 km,respectively,contrasting to the boundaries of 1951–2008.For the wettest period,that is,the 1890s to the 1910s,the shift of western and eastern boundaries was to the southwest by 125 km and 200 km,respectively,compared with that in the 1951–2008 period.This study serves as a reference for identifying a climatically sensitive area and planning future land use and agricultural production in the study area.

从碳循环到减排国际合作的科学逻辑

在《普通高中地理课程标准(2017年版)》(以下简称“地理新课标”)选择性必修3“资源、环境与国家安全”中,“内容要求3.5”的主题是全球气候变化与国家安全,落脚在“碳减排”的“国际合作”行为。此条内容要求的科学逻辑是:“碳排放—碳循环—温室效应—环境影响(全球变暖)—国家安全风险—碳减排—国际合作”,体现在自然环境所允许的空间内发展是人地和谐的自然基础这一基本思想;在整个逻辑链条中,“国家安全风险”环节的内容是理解“碳减排”和“国际合作”行为的重要性。全球气候变化与国家安全问题是现实的全球尺度人地关系问题,此条内容要求覆盖了人影响地、地影响人、人对影响的反馈等人地相互作用过程的主要环节,有助于更好地培养学生的人地协调观。

中学地理“粮食安全”情境教学历史案例开发

民为国基,谷为民命,保障粮食安全作为一项长期而又艰巨的任务是我国的一项基本国策。粮食安全作为人教版高中地理选择性必修3《资源、环境与国家安全》中的一节,是国家安全教育的重要内容。鉴于新一代青少年对粮食安全危机缺乏切身感受,笔者通过阅读史料,面向高中地理教学编写了历史粮食安全案例,目的是把没有经历过饥荒的青少年带入到真实历史情境中,具体感知实现粮食安全的途径及相关的潜在风险,认识耕地保护对粮食安全的重要性,加深维护粮食安全乃至国家发展安全的意识,更好地落实高中地理的教学目标。

Global Environmental Change and National Security of China

The concept of security has been redefined since the 1990s. As one of the important factors threatening human security, global environmental change has become a new challenge to the national security and social development. The national security problems caused by global environmental change, on one hand, are closely related to the global environmental problems, and, on the other hand, are manifested in the conflicts of international affairs. The global environmental change severely challenges the future development of China. When it comes to the study on human dimensions of global environmental change in China, much more attention should be paid to issues of important environmental change that may have great impacts on the national security of China, to the scientific assessment of the vulnerabilities of the natural and socialeconomic system of China to the impacts of global environmental change, and to the active establishment of the national risk management system, in which global environmental change should be included, so as to make contribution to sustainable development and construction of harmonious society of China.

乡村公共建筑——张家界马头溪村榨油坊的历史价值与现代重构

传统村落作为中国乡村的代表,具有民族地域性,其发展也面临困难:一是人口流失和老龄化,出现空心村,乡村丧失活力;二是居住分散且缺少公共活动场所,不利于村民交流;三是经济条件落后,村民生产生活现代化需求得不到满足;四是传统文化传承缺失,人们重物质追求,而忽略了精神文化传承,对传统文化不够重视,导致传统建筑被拆毁,取而代之的是风貌格格不入的“方盒子建筑”。

清代自然灾害所致极端人口死亡事件的识别及特征

大规模的人口死亡受到自然系统和社会经济系统的共同影响,是自然灾害对人口系统造成的主要威胁之一。基于从“清代自然灾害信息集成数据库”中提取的人口死亡记录,识别并分析了清代发生的极端人口死亡事件特征,重建了清代极端人口死亡强度、年次及省次的10 a序列,并分析其空间分布和发生原因。结论表明:①清代共有91年发生过极端人口死亡事件,平均约每3 a发生一次。极端人口死亡事件发生的频率和强度存在一定的阶段性变化,1644年—18世纪20年代为与清代总体平均值接近的阶段,18世纪30年代—19世纪初是清代极端人口死亡事件发生频率和强度均最低的时期,19世纪10年代—1911年为事件发生的稳定高值期。②清代共有18个省级政区发生过极端人口死亡事件,1644年—18世纪20年代极端事件分布较广但主要为较低强度的事件,18世纪30年代—19世纪初极端事件的分布范围最小,19世纪10年代—1911年事件分布广、强度高,致死因子出现明显的南涝北旱分异。③疫病、饥荒和洪涝在各阶段均是造成极端人口死亡事件的主要因子,干旱、雨水和风暴潮则是主要的间接致死因子。

过去2000年中国农耕区拓展与垦殖率变化基本特征

通过梳理和集成近年研究成果,综述了过去2000年中国主要农耕区拓展的阶段性及其间全国耕地面积和其中近千年垦殖率变化的主要特征。主要结论有:①中国主要农耕区第一次大规模拓展出现在西汉,从黄河中下游拓至整个长江以北地区;第二次在唐宋时期,主要是长江以南农耕区域从平原低地拓垦至丘陵山地;第三次在清中叶以后,主要是对东北、西北和西南等边疆地区的拓垦和山地的深度开发。②过去2000年中国耕地面积呈波动增加趋势,公元初突破5亿亩(1亩≈667 m2),8世纪前期突破6亿亩,11世纪后半叶达近8亿亩,16世纪后期突破10亿亩,19世纪前期突破12亿亩,1953年逾16亿亩,1980年逾20亿亩。③中国耕地空间分布的主体格局至11世纪前后就已基本奠定。1080年前后,黄淮海、关中平原等的垦殖率达30%以上,长江三角洲、鄱阳湖平原、两湖平原和四川盆地等达30%左右。1850年前后,华北平原、汾渭盆地和陇东地区、四川盆地、两湖平原、鄱阳湖平原及长三角地区等的垦殖率均超过30%。2000年前后,东北平原、黄淮海地区、汾渭盆地和陇东地区、四川盆地、长江中下游平原等农业区中有2/3以上垦殖率超过50%,辽西丘陵、坝上高原、黄土高原及南方各省的丘陵山地也多达15%以上;西北绿洲农业带及青藏高原河谷农业带的局部地区也达50%以上。

中国历史时期气候变化与粮价关系研究进展

粮食安全是国际气候变化研究领域的热点问题,也是中国历史时期气候变化影响研究的重要内容。中国历史气候变化与粮价关系研究,能够为深入理解现代气候变化对粮食安全的影响提供借鉴。本文从研究内容、研究热点、研究方法和研究结论等方面综述了中国历史时期气候变化与粮价关系研究的进展,包括极端气候事件对粮价波动的影响、气候波动与粮价的关联等研究。主要认识有:(1)相关研究主要集中于清代长江中下游、东南沿海、华南及华北地区,重点关注粮价波动对极端气候事件的响应,气候要素、极端气候事件与粮价变化的长时间尺度关联等问题;(2)主要研究方法包括案例史实陈述、时空对比、综合分析等定性方法,以及数据统计、时间序列对比、相关分析等定量方法,近年来格兰杰因果检验、小波分析、空间自相关、时间序列模型等定量实证分析方法得到了更广泛的应用;(3)极端气候事件对粮价波动的影响已经得到广泛证实,而气候波动与粮价的长期关联还存在较大争议。未来将粮价、社会经济因素及历史过程等纳入气候变化影响粮食安全的概念体系,有助于深化对气候变化与粮价关系的时空差异、非线性特征的认识。

Cropland cover change in Northeast China during the past 300 years

Land use/cover change induced by human activities has emerged as a "global" phenomenon with Earth system consequences. Northeast China is an area where the largest land cultivation activities by migrants have happened in China during the past 300 years. In this paper, methods including documentary data calibration and multi-sourced data conversion model are used to reconstruct historical cropland cover change in Northeast China during the past 300 years. It is concluded that human beings have remarkably changed the natural landscape of the region by land cultivation in the past 300 years. Cropland area has increased almost exponentially during the past 300 years, especially during the past 100 years when the ratio of cropland cover changed from 10% to 20%. Until the middle of the 19th century, the agricultural area was still mainly restricted in Liaoning Province. From the late 19th century to the early 20th century, dramatic changes took place when the northern boundary of cultivation had extended to the middle of Heilongjiang Province. During the 20th century, three agricultural regions with high ratio of cropland cover were formed after the two phases of spatial expansion of cropland area in 1900s—1930s and 1950s—1980s. Since 1930s—1940s, the expansion of new cultivated area have invaded the forest lands especially in Jilin and Heilongjiang Provinces.

Accuracy assessment of global historical cropland datasets based on regional reconstructed historical data——A case study in Northeast China

Historical cropland datasets are fundamental for quantifying the effects of human land use activities on climatic change and the carbon cycle. Two representative global land-use datasets, the Global Land Use Database (termed SAGE dataset) and the Historical Database of the Global Environment (termed HYDE dataset) have been established and used widely. Despite improvement of data quality and methodologies for extracting historical land use information, certain dataset limitations exist that need to be quantified and communicated to users so that they can make informed decisions on whether and how these land-use products should be used. The Cropland data of Northeast China (CNEC) is based on calibrated historical data and a multi-sourced data conversion model, and reconstructs cropland cover change in Northeast China over the last 300 years. Us- ing the CNEC as a reference, we evaluated the accuracy of cropland cover for SAGE and HYDE in Northeast China at spatial scales ranging from the entire Northeast China to provinces and even individual raster grid cells. Neither SAGE nor HYDE reflects real historical land reclamation. Cropland areas in SAGE are overestimated by 20.98 times in 1700 to 1.6 times in 1990. Although HYDE is better, there are significant disagreements in cropland area and distribution between HYDE and CNEC, especially in the 18th and 19th centuries. The proportion of total grid cells whose relative error was greater than 100% was 63.55% in 1700 and 53.27% in 1780. Global cropland dataset errors over Northeast China originate mainly from both the reverse calculation method for historical cropland data based on modern spatial patterns, and modern land-use outputs from satellite data.

Social impacts of the climatic shift around the turn of the 19th century on the North China Plain

Historical case studies of climate change impacts and the resulting social responses can provide analogies for better understanding the impacts of current and future climate changes.Around the turn of the 19th century,the climate of the North China Plain experienced a shift from a relatively warm stage in the 18th century to a colder stage in the 19th century,which was characterised by a much colder climate and more frequent and severe floods and droughts.Historical information about refugees,social disorder,grain transportation,and disaster relief on the North China Plain in 1780-1819 is collected from the Veritable Records of the Qing Dynasty(a collection of official records).The mechanism of climate change affecting the food security of the society,as indicated by the development of a refugee problem around the turn of the 19th century,is analyzed by examining the social vulnerability.There are four basic findings:(1) In the 40 years from 1780-1819,the society on the North China Plain was unstable and characterised by a significant deterioration of the refugee situation.The number of refugees increased markedly,and their behaviour became increasingly violent.In the 1780s,most of the disaster victims chose to stay at their residences waiting for relief.From 1790 to 1800,hundreds of thousands of refugees migrated to northeast China.In the 1810s,the frequency of farmer rebellions increased sharply.(2) The increase in instability corresponded to the climatic cooling over the same time period.The increased instability was a result of the negative impacts of climate change accumulating and transmitting to the social level.(3) For food security,a precondition for the negative impacts of climate change on human society was the vulnerability of the regional socioeconomic system,which had a high sensitivity and low capacity to respond.This vulnerability could be described by the following three observations:① The regional balance of supply and demand for food was in a critical state,which led to a high sensitivity and dramatic reduction in yield that was caused by climate change;② the capacity for disaster relief efforts by the government was too low to meet the needs of crisis management;③ the capacity for refugees' resettlement in eastern Inner Mongolia and northeast China,which both border the North China Plain,was severely restricted by climatic conditions or the quarantine policy.(4) It is estimated that climate change caused the social vulnerability to reach a critical level approximately 20 years earlier on the North China Plain.

Societal response to challenges of global change and human sustainable development

It is now widely accepted that carbon emission from human activities is an important driving force in global warming, and global change has a deep impact on sustainable development of human society. To meet the challenges of global change, the international community has reached a consensus that developed countries take strict actions in emission reduction, whereas developing countries take spontaneous efforts in reducing emissions under the guiding principle of common but differentiated responsibilities, with an agreed goal to restrict global surface temperature increase due to human activities to within 2℃ of pre-industrial levels. However, there is no clear pathway to reach this goal. A number of related questions must be addressed on principles to be followed, research emphasis and policy measures. Here we argue that response policies to address global change issues must be based on balanced development at regional and international levels, and on advancements in science and technology. This requires consideration of harmony not only between humans and nature but also within human societies, to properly deal with the relationship between global change and sustainable development. We must make equal efforts toward carbon emission reduction and carbon sequestration, and toward mitigation and adaptation. There should be more research support to reduce uncertainties in our understanding of global change. Addressing the challenges of global change creates great opportunities for the development of human society. This will facilitate transformation of energy use structure, improve and restore ecological functioning of the earth environment, transform production modes and ways of living in human society, and promote harmonic and balanced development at regional and international levels.

Transmission of climate change impacts from temperature change to grain harvests, famines and peasant uprisings in the historical China

Because of the complexity of social responses to climate change,as well as limitations of proxy data concerning interactions between climate change and human responses,the social impacts of past climate change and associated response mechanisms,thus,require further investigation.To shed light on the transmission of climate change impacts within historical Chinese society,we selected 30-year resolution sequences of temperature anomalies in eastern China and 10-year resolution sequences of grain harvest grades,famine indices,and frequencies of peasant uprisings in China over the past 2000 years.Using a food security perspective,we analyzed the impacts of temperature changes historically transmitted through Chinese production,population,and social subsystems,and differences in transmission characteristics between cold and warm units.Our results were as follows.(1)From 210 BC to 1910 AD,temperature changes in China were significantly positively correlated with grain harvest grades(correlation coefficient,0.338),and significantly negatively correlated with famine indices,and frequencies of peasant uprisings(correlation coefficients,-0.301 and-0.277,respectively).The correlation coefficients between famine indices and grain harvest grades or frequencies of peasant uprisings were very low.(2)There was a higher proportion of bumper or normal harvests(86.5%of the total decades),more moderate and mild famines(76%),and a lower proportion of peasant uprisings(33.3%)in the 30-year warm units.Conversely,there was a higher proportion of poor or normal harvests(70.7%),a greater proportion of moderate and severe famines(77.6%),and more peasant uprisings(51.7%)in the 30-year cold units.(3)Of the 23 main transmission pathways extending from temperature change to the social subsystem,13 occurred in cold units,of which 7 had an endpoint of peasant uprisings,and 10 occurred in warm units of which 3 had an endpoint of peasant uprisings.The main transmission pathways that were more likely to be associated with the impacts of temperature change were:Cold→poor harvests→severe famines→more uprisings;cold→poor harvests→moderate famines→more uprisings;warm→bumper harvests→mild famines→no uprisings;warm→bumper harvests→moderate harvests→no uprisings;warm→normal harvests→mild famines→no uprisings;and warm→normal harvests→moderate famines→no uprisings.(4)The transmission of the impacts of temperature change was a complex process.Within this process,famine was most prone to being modulated by human society.In the transmission pathways from the production to the social subsystem,there was a stepwise decrease in the occurrence rate of decades that were probably affected by climate change.In all cold units,10.4%of decades ending in more uprisings were most likely to be associated with the impacts of temperature change.In all warm units,47.9%of decades ending in no uprisings were most likely to be associated with the impacts of temperature change.This research can contribute a better understanding on the past interaction mechanisms and processes within the human-climate-ecosystem complex,as well as a better response to the impacts of the ongoing climate change.