南方水稻复种指数变化对国家粮食产能的影响及其政策启示（英文）

Changes in rice production in Southern China are crucial to national food security. This study employed Landsat images to map the distributions of paddy rice-cropping systems in Southern China in 1990 and 2015. The impact of rice multiple cropping index changes on grain production capacity was then evaluated. Three important results were obtained for the 1990 to 2015 study period. First, the multiple cropping index for rice decreased from 148.3% to 129.3%, and 253.16×10~4 ha of land area was converted from double-cropping to single-cropping rice, termed "double to single". The area with the most dramatic changes is in the Middle-Lower Yangtze Plain. The rice-cropping system distribution in Southern China showed a change from north to south with double-cropping rice shrinking and single-cropping rice expanding. Second, the "double to single" conversion led to a reduction of 6.1% and 2.6% in rice and grain production, respectively. Hunan and Jiangxi Provinces, located in the main rice producing areas, and Zhejiang, which has shown better economic development, exhibited large reductions in rice production due to the "double to single" conversion, all exceeding 13%. Third, the grain production capacity of converted "double to single" paddy fields is equivalent to that of 223.3 × 10~4 ha of newly reclaimed cultivated land, which is 54% of the total newly cultivated land reclaimed through the 2001–2015 land consolidation project. It is also 1.7 times the target goal for newly cultivated land in the national land consolidation plan for 2016–2020. Making full use of the converted "double to single" paddy fields can save 167.44 billion yuan in newly reclaimed cultivated land costs. Therefore, instead of pursuing low-quality new arable land, it is better to make full use of the existing high-quality arable land. Based on these results, the government should change the assessment method for cultivated land balance, and incorporate the sown area increased by improving the multiple cropping index into the cultivated land compensation indicator.     

Land use change and its ecological effect in Qian＇an County of Jilin Province

Based on GIS and statistical methods, with the help of searching historical literatures and calculating the landscape indices, the land use changes of Qian‘an County in both spatial and temporal aspects from 1945 to 1996 has been analyzed in this paper. And the driving forces of land use changes and their ecological effects are discussed too. The main findings of this study are as follows: (1) Land use changed greatly in Qian‘an during 1945-1996, characterized by a decrease in grassland, wetland and water bodies, and an increase in cultivated land, saline-alkali land, and the land for housing and other construction purposes. Grassland decreased by 175,828.66 ha, and cultivated land increased by 102,137.23 ha over the half century. Accordingly, the main landscape type changed from a steppe landscape to a managed agricultural ecosystem. (2) Results of correlation analysis show that the land use change in the study area was mainly driven by the socioeconomic factors. (3) The ecological effects of land use change in the area are characterized by serious salinization, degression of soil fertility and the weakening, of landscaoe suitability.     

Land use change and its ecological effect in Qian'an County of Jilin Province

Based on GIS and statistical methods, with the help of searching historical literatures and calculating the landscape indices, the land use changes of Qian'an County in both spatial and temporal aspects from 1945 to 1996 has been analyzed in this paper. And the driving forces of land use changes and their ecological effects are discussed too. The main findings of this study are as follows: (1) Land use changed greatly in Qian'an during 1945-1996, characterized by a decrease in grassland, wetland and water bodies, and an increase in cultivated land, saline-alkali land, and the land for housing and other construction purposes. Grassland decreased by 175,828.66 ha, and cultivated land increased by 102,137.23 ha over the half century. Accordingly, the main landscape type changed from a steppe landscape to a managed agricultural ecosystem. (2) Results of correlation analysis show that the land use change in the study area was mainly driven by the socioeconomic factors.　(3) The ecological effects of land use change in the area are characterized by serious salinization, degression of soil fertility and the weakening of landscape suitability.     

乾安县土地利用变化及其生态效应

Based on GIS and statistical methods, with the help of searching historical literatures andcalculating the landscape indices, the land use changes of Qian'an County in both spatial and temporalaspects from 1945 to 1996 has been analyzed in this paper. And the driving forces of land use changesand their ecological effects are discussed too. The main findings of this study are as follows:(1)Landuse changed greatly in Qian'an during 1945-1996, characterized by a decrease in grassland, wetlandand water bodies,and an increase in cultivated land, saline-alkali land, and the land for housing andother construction purposes. Grassland decreased by 175,828.66 ha, and cultivated land increased by     

1987-2007年土耳其伊斯坦布尔黑海沿岸土地利用变化(英文)

Recently,important land use changes have occurred in the Black Sea coastal regions of stanbul due to urban growth and population increases.The objective of this study was to determine changes in land use in the Black Sea coastal regions of stanbul between 1987 and 2007.Landsat 30 m satellite images from 1987 and 2007 are used in the study.The study area is 1000 m in width from the coastline to the land and the study has been carried out using the controlled classification method to classify areas into residential,agricultural,forest,bare land,brush/grassland,and lake/pond land classes.Land use changes between 1987 and 2007 were analysed in detail.Residential areas of the Black Sea coastal regions of stanbul increased by 122% over the two decades.Also an increase of 55% in agriculture areas was observed,while there were decreases of 26% in forest areas and 15% in free land.A 21% increase in the area of brush and grassland took place.Furthermore 79% of the study area was covered by residential areas in 2007.It is probable that pressure on the stanbul coastal regions will continue due to migraton and rapid urbanization.Therefore,Istanbul’s Black Sea coastal regions should be maintained using a sustainable coastal management plan.     

近两百年江苏省城乡建设用地数量估算与空间重建（英文）

Land cover is the most evident landscape signal to characterize the influence of human activities on terrestrial ecosystems.Since the industrial revolution,the expansion of construction land has profoundly changed the status of land use coverage and changes.This study is proposed to reconstruct the spatial pattern of construction land(urban construction land and rural settlement land)for five historical periods over the past 200 years in Jiangsu Province with 200 m′200 m grids on the basis of quantitative estimation.Urban construction land is estimated based on data about city walls,four gates along walls,and other socio-economic factors.Rural settlement land is calculated based on the rural population and per capita housing allowance.The spatial pattern of historical construction land is simulated based on the distribution of modern construction land in 1985 with a quantitative-boundarysuitability control method and thorough consideration over connectivity of different land use types.The study concludes that:(1)the amount of construction land in Jiangsu Province is estimated at 963.46 km~2 in 1820,1043.46 km~2 in 1911,1672.40 km~2 in 1936,1980.34 km~2 in1952 and 10,687.20 km~2 in 1985;and(2)the spatial distribution of construction land features the great proclivity to water bodies and main roads and the strong polarization of existent residence.The results are verified directly and indirectly by applying the trend verification of construction land changes and patterns,the correlation analysis between rural settlement land and local arable land,and quantitative accuracy test of the reconstructed construction land to actual historical survey maps covering four sample regions in 1936.     

Effect of farmland expansion on drought over the past century in Songnen Plain,Northeast China

The effects of human activities on climate change are a significant area of research in the field of global environmental change. Land use and land cover change(LUCC) has a greater effect on climate than greenhouse gases, and the effect of farmland expansion on regional drought is particularly important. From the 1910 s to the 2010 s, cultivated land in Songnen Plain increased by 2.67 times, the area of cultivated land increased from 4.92×10~4 km~2 to 13.14×10~4 km~2, and its percentage of all land increased from 25% to 70%. This provides an opportunity to study the effects of the conversion of natural grassland to farmland on climate. In this study, the drought indices in Songnen Plain were evaluated from the 1910 s to the 2010 s, and the effect of farmland expansion on drought was investigated using statistical methods and the Weather Research and Forecasting Model based on UK's Climatic Research Unit data. The resulting dryness index, Palmer drought severity index, and standardized precipitation index values indicated a significant drying trend in the study area from 1981 to 2010. This trend can be attributed to increases in maximum temperature and diurnal temperature range, which increased the degree of drought. Based on statistical analysis and simulation, the maximum temperature, diurnal temperature range, and sensible heat flux increased during the growing season in Songnen Plain over the past 100 years, while the minimum temperature and latent heat flux decreased. The findings indicate that farmland expansion caused a drying trend in Songnen Plain during the study period.     

汶川地震灾后重建地区的人口容量分析

Assessment of population carrying capacity is a key task in the reconstruction planning of areas struck by disasters, in which the precision of estimation is required. This study developed a decision-making model for estimating the population capacity of the involved townships and cities in the 2008 Wenchuan Earthquake based on the assessment of the suitability for reconstruction of the areas. Through analysis, arable land resources were argued to be the critical constraint of population capacity in these areas. Then, the spatial differentiations of the post-quake development conditions across different regions were analyzed with respect to their natural environments, socio-economic development and quake damages. The expected levels of urbanization, family incomes and income structures, output levels of land, and the reliance of agricultural population on arable land were estimated by different regions. With these parameters, the population capacities of the involved townships and cities in three scenarios were estimated. The total population capacity of the entire areas is abundant compared with the actual post-quake population; however, the status of over-population substantially varies across space. It was suggested to put the emphasis of post-quake resettlement policy on those counties where earthquake had been the main causes of over-population. In the Full Recovery Scenario, three mountain counties were identified including Wenchuan, Beichuan and Maoxian, with a total over-population of about 100,000 people.     

黄土高原多沙区环境因子对土地利用变化空间异质性的影响(英文)

In areas with topographic heterogeneity, land use change is spatially variable and influenced by climate, soil properties, and topography. To better understand this variability in the high-sediment region of the Loess Plateau in which soil loss is most severe and sediment diameter is larger than in other regions of the plateau, this study builds some indicators to identify the characteristics of land use change and then analyze the spatial variability as it is affected by climate, soil property, and topography. We build two indicators, a land use change intensity index and a vegetation change index, to characterize the intensity of land use change, and the degree of vegetation restoration, respectively. Based on a subsection mean method, the two indicators are then used to assess the spatial variability of land use change affected by climatic, edaphic, and topographic elements. The results indicate that: 1) Land use changed significantly in the period 1998–2010. The total area experiencing land use change was 42,302 km2, accounting for 22.57%of the study area. High-coverage grassland, other woodland, and forest increased significantly, while low-coverage grassland and farmland decreased in 2010 compared with 1998. 2) Land use change occurred primarily west of the Yellow River, between 35 and 38 degrees north latitude. The four transformation types, including(a) low-coverage grassland to medium-coverage grassland,(b) medium-coverage grassland to high-coverage grassland,(c) farmland to other woodland, and(d) farmland to medium-coverage grassland, were the primary types of land use change, together constituting 60% of the area experiencing land use change. 3) The spatial variability of land use change was significantly affected by properties of dryness/wetness, soil conditions and slope gradient. In general, land use changed dramatically in semi-arid regions, remained relativelystable in arid regions, changed significantly in clay-rich soil, remained relatively stable in clay-poor soil, changed dramatically in steeper slopes, and remained relatively stable in tablelands and low-lying regions. The increase in vegetation coincided with increasing changes in land use for each physical element. These findings allow for an evaluation of the effect of the Grain to Green Program, and are applicable to the design of soil and water conservation projects on the Loess Plateau of China.     

The effect of environmental factors on spatial variability in land use change in the high-sediment region of China’s Loess Plateau

In areas with topographic heterogeneity, land use change is spatially variable and influenced by climate, soil properties, and topography. To better understand this variability in the high-sediment region of the Loess Plateau in which soil loss is most severe and sediment diameter is larger than in other regions of the plateau, this study builds some indicators to identify the characteristics of land use change and then analyze the spatial variability as it is affected by climate, soil property, and topography. We build two indicators, a land use change intensity index and a vegetation change index, to characterize the intensity of land use change, and the degree of vegetation restoration, respectively. Based on a subsection mean method, the two indicators are then used to assess the spatial variability of land use change affected by climatic, edaphic, and topographic elements. The results indicate that： 1） Land use changed significantly in the period 1998-2010. The total area experiencing land use change was 42,302 km2, accounting for 22.57%of the study area. High-coverage grassland, other woodland, and forest increased significantly, while low-coverage grassland and farmland decreased in 2010 compared with 1998.2） Land use change occurred primarily west of the Yellow River, between 35 and 38 degrees north latitude. The four transformation types, including （a） low-coverage grassland to medium-coverage grassland, （b） medium-coverage grassland to high-coverage grassland, （c） farmland to other woodland, and （d） farmland to medium-coverage grassland, were the primary types of land use change, together constituting 60% of the area experiencing land use change. 3） The spatial variability of land use change was significantly affected by properties of dryness/wetness, soil conditions and slope gradient. In general, land use changed dramatically in semi-arid regions, remained relatively stable in arid regions, changed significantly in clay-rich soil, remained relatively stable in clay-poor soil, changed dramatically in steeper slopes, and remained relatively stable in tablelands and low-lying regions. The increase in vegetation coincided with increasing changes in land use for each physical element. These findings allow for an evaluation of the effect of the Grain to Green Program, and are applicable to the design of soil and water conservation projects on the Loess Plateau of China.     

On the land use in Three Gorges Reservoir area

In this study the arable land changes in two counties (Zigui and Xingshan) in the Three Gorges Reservoir area in China are investigated. The statistical data from the officially published statistical books are used to study these changes in the two counties during the past 50 years since 1949. The changes of arable land, changes of arable land per capita, and changes of multiple crop index in Zigui and Xingshan counties are examined. Using an index method, we conclude that the two counties are critical in the sustainable utilization of arable land.     

新疆南疆地区土地利用变化及其生态效应

基于GIS平台,以新疆各县市统计数据为基础,对南疆土地利用变化特征及其生态效应进行分析。分析得出:①近12 a间耕地、园地、林地、水域及建设用地面积增加,而草地和未利用土地面积减少。12 a间土地利用综合动态度为0.88%,园地、建设用地和耕地的年变化率较大;林地、草地、水域和未利用土地的较低。土地利用变化存在明显的区域差异,巴州除未利用土地以外,土地利用类型的变幅均大于全区相应土地利用类型的变幅,和田所有土地利用类型的变幅均小于全区的变幅。②绿洲耕地面积的扩展以牺牲自然荒漠植被为代价,致使绿洲生态问题日益突出,主要表现为植被退化、沙漠化、生境质量下降、土壤盐渍化和水质恶化等。     

区域耕地动态变化及可持续利用评价——以河北省黑龙港地区为例

耕地作为土地中的精华 ,其动态变化及可持续利用无疑是影响区域可持续发展的关键问题。河北省黑龙港地区旱、涝、盐、碱灾害严重 ,是黄淮海平原水土资源条件最差的地区。近年来 ,随着经济发展和人口增长 ,人地矛盾日益突出 ,成为该区域可持续发展的一个关键问题。本文利用黑龙港地区近 5 0年耕地长序列统计资料和近 5年的土地详查数据 ,揭示了耕地数量变化的基本过程及其空间差异 ,并进一步对耕地资源利用的可持续性进行了评价。研究表明 ,近 5 0年来 ,黑龙港地区耕地数量呈明显的波动减少趋势 ,经历了由增加→急剧减→缓慢减少的基本变化过程 ,其中在 1 95 5～ 1 95 8年和 1 96 5～ 1 978年出现两次明显的耕地流失高峰 ;全区域耕地资源利用处于临界可持续 ,其综合指数为 48.2 5。     

Process and mechanism of arable land change in Hebei Province during the past 50 years

1 Introduction Arable land is the core of land resources and its dynamic change seriously affects regional sustainable development. Hebei Province, with a large population, is an agricultural province. With the highspeed economic development, population growth and urbanization, a great amount of arable land has been lost and the land shortage has become more serious. Therefore, arable land change and its driving forces should be studied in order to realize the sustainable agricultural develo…     

Process and mechanism of arable land change in Hebei Province during the past 50 years

Hebei Province is one of the regions with most densely population, fastest economic growth and most intensive land use in China. The contradiction of land shortage sharpened by high-speed economic development with population growth has become a serious problem, which has restricted regional sustainable development.This paper revealed the basic process, regional differences of change and the gravity center of arable land area according to the long-series statistical data of arable land during the past 50 years. On the basis of the above mentioned, the major driving forces that influence the changes of the arable land are discussed. The research results indicate that there is a trend of obvious fluctuating decrease in arable land area during the last 50 years. The changes of arable land area undergo the process from increase to sharp decrease to gently decrease. The regional disparity of change in arable land area is very notable and the gravity center of arable land area moves to the northeast 49.22 km. Regarding the decrease in arable land, the direct driving forces include adjustments of agricultural structure and reclamation, and indirect driving forces include advance in technology, economic interest and population growth etc.     

中国适垦耕地空间分异特征研究

基于GIS空间分析技术,利用数字地形高程图生成地形高程和坡度分级图,将地形高程分级图、地形坡度分级图、2000年耕地分布图和分县行政区划图叠加,提取2000年分县耕地地形分异数据,计算2006年分县适垦耕地面积,以适垦耕地指数和人均适垦耕地面积为指标,分析我国适垦耕地的空间分异特征。结果表明:1)我国耕地的地形分异特点是随着地形高程和坡度的增加,耕地面积均呈现快速下降的趋势,耕地主要集中于海拔500 m以下且坡度较小的地域。2)适垦耕地的空间分异主要受地形条件控制,海拔较低、地形平缓的平原、盆地和河谷适垦耕地指数一般在50%以上,而海拔较高、地形起伏较大的高原、山地和丘陵地区指数值普遍低于30%。3)我国人均适垦耕地面积空间分布的总体特征是北多南少,人均适垦耕地面积在0.2 hm2以上的高类和较高类大都分布在北方地区,而人均适垦耕地面积在0.067 hm2以下的低类和较低类主要集中于青藏高原及东南沿海地区。     

基于主成分分析法的钦州市耕地面积变化及其驱动力分析

以钦州市为例,采用主成分分析方法,从经济、人口、农业和土地4个方面选取了13个因子,分析其在2001~2010年对耕地面积变化的影响,揭示耕地面积变化的作用机制,从而为制定合理的耕地保护政策提供依据。研究结果表明：① 钦州市耕地面积总体呈逐年下降趋势,年平均减少约460 hm²。② 钦州市耕地面积变化的主要因子是经济社会发展、人口增加和农业生产发展,这3者构成了耕地面积变化主要驱动力。③ 可以从减少建设占用、加强土地开发利用、加强农业结构调整的引导和管理等3个方面遏制钦州市耕地面积减少的势头。     

过去300 a大清河上游南部流域耕地变化重建

过去300 a耕地变化重建是环境变化研究的基础。华北地区河湖演变对历史土地开垦的影响需要在历史耕地重建时予以考虑。论文基于清代地方志、民国统计资料和现代土地利用数据,通过量化坡度和历史时期潜在耕地垦殖率因子,建立宜垦性模型,重建过去300 a白洋淀与大清河上游南部流域5个时间断面上空间分辨率为1 km×1 km的耕地变化,并结合大清河南支的河道变迁和白洋淀演变过程分析了县域尺度下河道变迁、湖群演变对土地开垦过程的影响。结果表明：① 近300 a来研究区开垦范围向山区扩展,开垦强度不断加深,平均垦殖率由1646年的0.162增至1980年代的0.579;② 白洋淀收缩为安新、容城、任丘、高阳和蠡县土地开垦提供良好的物质基础,清中后期5县垦殖率较同期周围县高约3%~40%不等,且增长速度明显快于周围县;③ 古河道为肃宁、河间、任丘和安国的土地开垦提供了物质基础,河流改道后肃宁、河间和任丘的垦殖率分别增长为原来的2.12、2.6和2.86倍;安国垦殖率增长了37%,为同期增长最为显著的县;④ 新河道虽会冲毁部分土地,但泛滥区却能为土地开垦提供物质基础,故途经地垦殖率有增有减,蠡县和高阳的垦殖率分别增加为原来的1.80倍和1.88倍,望都、清苑垦殖率分别增加3%、4%,定州垦殖率减少4%。     

安康市土地利用/覆盖变化的驱动因素分析

通过分析安康市2005～ 2010年土地利用详查和变更数据,运用数理统计方法和主成分分析法对安康市11个县市区进行土地利用数量变化及土地利用程度变化进行分析,在此基础上提取影响土地利用变化的驱动因子,分析各项指标的变化与影响.结果表明：它的土地利用类型数量总体上呈现耕地、未利用地、牧草地面积减小和园地、林地、城乡建设用地、交通运输用地、水利设施用地面积增大的趋势.其中,经济增长、城市化发展与人口增长三个因素是安康市土地利用变化的主要驱动因素.     

On arable land changes in Shandong Province and their driving forces

The decrease of total cultivated area and the lower per capita available arable land resource are now serious problems in Shandong Province, a major agricultural province in China. These problems will become more serious along with the further development of economy. In this paper, based on the statistical information at provincial and county levels, the changes of arable land in Shandong Province and their driving forces during the last 50 years are analyzed. The general changing trends of arable land and per capita available arable land are reducing, and the trends of decrease will continue when the economy is developing. The result of GIS spatial analysis shows that the change of the arable land use in Shandong Province has a regional difference. Eight variables having influences on cultivated land change are analyzed by principal component analysis. The results show that the dynamic development of economy, pressure of social system and progress of scientific techniques in agriculture are the main causes for cultivated land reduction. The principal factors which can be considered as driving forces for arable land change include per capita net living space, total population and per ha grain yield. By using regressive equation, along with analysis on population growth and economic development, cultivated areas in Shandong Province in 2005 and 2010 are predicted respectively. The predicted cultivated areas in Shandong will be 6435.47 thousand ha in 2005 and 6336.23 thousand ha in 2010 respectively.