近20年中国耕地复种指数的时空变化

多熟种植是中国重要的种植制度,对保障国家食物安全和促进农村经济发展有十分重要的意义。复种指数受自然条件和农村社会状况的影响处于不断变化之中,及时获取其变化信息是国家食物安全评估和农业发展科学决策的基础。近年来对食物安全的研究集中于耕地面积变化的影响,对复种指数变化及其影响的研究较少。作物种植面积和复种指数变化的估计一直以行政区划为单元的统计数据为基础,但获得这些数据费时费力,时效性和可靠性都比较差,更缺乏准确的空间和时间变化信息。卫星遥感是探测大尺度土地覆被格局实时变化的最有效手段,因此可以作为获取全国和区域尺度作物复种指数变化信息的重要途径。作者应用多时相NOAA/AVHRR遥感观测数据和峰值特征点检测法提取全国尺度的复种指数,并分析其从20世纪80年代初到90年代末的变化。结果表明全国复种指数整体增加,但在珠江三角洲、长江中下游、四川盆地丘陵山地以及山东丘陵等地区有所降低。复种指数下降的耕地占全国总面积15%左右。在四川盆地和黄淮海区,复种指数在平原地区有所增加或保持稳定,下降多发生在丘陵山地,但在长江中下游和华南精耕细作地区出现复种指数降低的趋势。     

Potential promoted productivity and spatial patterns of medium- and low-yield cropland land in China

With a continuously increasing population and better food consumption levels, improving the efficiency of arable land use and increasing its productivity have become fundamental strategies to meet the growing food security needs in China. A spatial distribution map of medium- and low-yield cropland is necessary to implement plans for cropland improvement. In this study, we developed a new method to identify high-, medium-, and low-yield cropland from Moderate Resolution Imaging Spectroradiometer (MODIS) data at a spatial resolution of 500 m. The method could be used to reflect the regional heterogeneity of cropland productivity because the classification standard was based on the regionalization of cropping systems in China. The results showed that the proportion of high-, medium-, and low-yield cropland in China was 21%, 39%, and 40%, respectively. About 75% of the low-yield cropland was located in hilly and mountainous areas, and about 53% of the high-yield cropland was located in plain areas. The five provinces with the largest area of high-yield cropland were all located in the Huang-Huai-Hai region, and the area amounted to 42% of the national high-yield cropland area. Meanwhile, the proportion of high-yield cropland was lower than 15% in Heilongjiang, Sichuan, and Inner Mongolia, which had the largest area allocated to cropland in China. If all the medium-yield cropland could be improved to the productive level of high-yield cropland and the low-yield cropland could be improved to the level of medium-yield cropland, the total productivity of the land would increase 19% and 24%, respectively.     

中国耕地中低产田空间分布格局及产能提升潜力（英文）

With a continuously increasing population and better food consumption levels, improving the efficiency of arable land use and increasing its productivity have become fundamental strategies to meet the growing food security needs in China. A spatial distribution map of medium- and low-yield cropland is necessary to implement plans for cropland improvement. In this study, we developed a new method to identify high-, medium-, and low-yield cropland from Moderate Resolution Imaging Spectroradiometer(MODIS) data at a spatial resolution of 500 m. The method could be used to reflect the regional heterogeneity of cropland productivity because the classification standard was based on the regionalization of cropping systems in China. The results showed that the proportion of high-, medium-, and low-yield cropland in China was 21%, 39%, and 40%, respectively. About 75% of the low-yield cropland was located in hilly and mountainous areas, and about 53% of the high-yield cropland was located in plain areas. The five provinces with the largest area of high-yield cropland were all located in the Huang-Huai-Hai region, and the area amounted to 42% of the national high-yield cropland area. Meanwhile, the proportion of high-yield cropland was lower than 15% in Heilongjiang, Sichuan, and Inner Mongolia, which had the largest area allocated to cropland in China. If all the medium-yield cropland could be improved to the productive level of high-yield cropland and the low-yield cropland could be improved to the level of medium-yield cropland, the total productivity of the land would increase 19% and 24%, respectively.     

中国农田生产力变化的空间格局及地形控制作用

中国政府高度重视粮食安全, 采取一系列措施提高粮食生产并取得了一定的成效, 但是20 世纪90 年代全球农业生产徘徊不前并不仅是一种由特定政策或市场因素导致的短期现象。因此, 认识在长时间尺度上农田生产力变化的特征及其控制因素对保障国家粮食安全、制定农业政策及调节生态系统服务功能具有重要意义, 研究稳定少动但对农田生产力形成有 重要影响的地形因子对农田生产力变化的作用是其中的一项重要内容。生态系统生产力遥感 机理模型能够清晰地表达国家尺度农田生产力的时空格局, 应用1981~2000 年的NOAA/AVHRR 卫星遥感数据驱动GLO-PEM 模型, 以10 年为时间尺度分析20 世纪80 年代 到90 年代农田生产力变化的空间格局特征。研究结果表明, 在10 年的时间尺度上, 地形特征控制着农田生产力变化空间格局分异规律, 农田生产力降低的几率随地形起伏度增大而增加, 山区耕地发生生产力下降的可能性比平原耕地高10%~30%。在研究时期内尽管中国农田生产力总量增加, 但仍有24%的农田发生农田生产力下降, 其中71%在丘陵山地, 尤其是地形起伏破碎的黄土高原及云贵高原地区。     

近20年中国农业主产区耕地资源质量和产能变化研究

依据全国土地利用图与土地资源质量评价图,分析1980s末至2005年末中国农业主产区内耕地资源数量和空间格局的动态变化,并对由此带来的耕地质量和产能的变化做出宏观评估。主要结论如下:1)2005年农业主产区耕地面积①为9 321.96万hm2,较1980s末增加175.53万hm2。2)耕地在空间上呈现"北增南减"的变化格局。北方的内蒙古东部区、新疆区、松嫩平原区和三江平原区为耕地净增加区,共增加354.41万hm2,各区分别增长10.29%、19.10%、10.91%和14.14%;偏南部的黄淮海区、长江中下游及江淮地区、华南蔗果区和四川盆地区为耕地净减少区,各区分别减少2.17%、2.00%、3.15%和5.61%。3)根据土地资源图对耕地质量的划分结果,20年间农业主产区内耕地面积和空间格局的变化导致一等耕地减少3.24%,二、三等耕地和宜林宜牧地分别增加2.91%、7.81%和14.10%。4)考虑各区耕地复种指数和耕地质量的影响,结合耕地单产数据进行耕地产能的核算,结果显示,在耕地数量净增1.92%的情况下,耕地的总体产能依然下降0.84%。     

1999-2013年中国耕地复种指数的时空演变格局

耕地复种是中国普遍的农业种植制度,对保障国家粮食安全和促进农村经济发展十分必要。本文基于1999-2013年1 km×1 km旬SPOT-NDVI数据和3期耕地数据,利用S-G （Savitzky-Golay）滤波方法,重建了农作物生长NDVI曲线;基于二次差分算法及相关阈值限定,提取了各时相复种指数;分析了1999-2013年中国耕地复种指数的时空变化过程。结果表明：① 中国耕地复种指数从北到南逐渐增加,其中种植制度上43.48%的耕地实行一年一熟,56.39%的耕地实行一年两熟,仅有0.13%的耕地实行一年三熟。② 1999-2013年间,中国耕地复种指数整体上呈现显著上升趋势,年均增加约为1.29%（P < 0.001）;但空间差异明显,复种指数显著降低（P < 0.1）的耕地仅占全国耕地的2.12%,主要分布在河北、北京、天津交界地区,安徽中部,四川的成都平原,江西的鄱阳湖平原,湖南的北部和南部以及广西的中部;16.40%的耕地复种指数显著上升（P < 0.1）,主要分布在甘肃的东部,陕西的渭河平原,山西的西部,河北、山东和天津交界处,山东的山东半岛和湖北的江汉平原。③ 耕地复种指数年际变化率与地形起伏和经济发展水平具有较好的相关关系：起伏度增强,复种指数上升;经济发展水平提高,复种指数降低。     

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。     

Land-cover and land-use change in a Mediterranean landscape: A spatial analysis of driving forces integrating biophysical and human factors

This article develops a spatial analysis applied to examine the main driving forces of land-cover and land-use (LCLU) change in a Mediterranean region. Three different tools have been used in order to differentiate LCLU changes, driving forces and landscape dynamics. LCLU changes have been quantified with remote sensing techniques, driving forces have been analysed with multiple logistic regressions combining biophysical and human variables, whereas landscape dynamics have been quantified using different metrics. Results show the intensification of subsidised herbaceous crops on the coastal agricultural plain, the abandonment of olive trees and vineyards in the transitional area and forest restoration in the mountainous subregion.     

鄱阳湖区2004-2010年水稻种植制度时空变化(英文)

Rice cropping systems not only characterize comprehensive utilization intensity of agricultural resources but also serve as the basis to enhance the provision services of agro-ecosystems.Yet,it is always affected by external factors,like agricultural policies.Since 2004,seven consecutive No.1 Central Documents issued by the Central Government have focused on agricultural development in China.So far,few studies have investigated the ef-fects of these policies on the rice cropping systems.In this study,based upon the long-term field survey information on paddy rice fields,we proposed a method to discriminate the rice cropping systems with Landsat data and quantified the spatial variations of rice cropping systems in the Poyang Lake Region(PLR),China.The results revealed that:(1) from 2004 to 2010,the decrement of paddy rice field was 46.76 km2 due to the land use change.(2) The temporal dynamics of NDVI derived from Landsat historical images could well characterize the temporal development of paddy rice fields.NDVI curves of single cropping rice fields showed one peak,while NDVI curves of double cropping rice fields displayed two peaks an-nually.NDVI of fallow field fluctuated between 0.15 and 0.40.NDVI of the flooded field during the transplanting period was relatively low,about 0.20±0.05,while NDVI during the period of panicle initiation to heading reached the highest level(above 0.80).Then,several temporal windows were determined based upon the NDVI variations of different rice cropping systems.(3) With the spatial pattern of paddy rice field and the NDVI threshold within optimum tem-poral windows,the spatial variation of rice cropping systems was very obvious,with an in-creased multiple cropping index of rice about 20.2% from 2004 to 2010.The result indicates that agricultural policies have greatly enhanced the food provision services in the PLR,China.     

环渤海地区农业地域功能演进及其影响因素

农业地域功能是农业地理学的重点理论问题之一,也是关乎粮食安全和区域农业可持续发展的重要实践课题。以环渤海地区为例,通过构建评价体系开展农业地域功能划分及其演进分析,利用空间计量模型诊断农业地域多功能形成的影响因素。结果表明：① 环渤海地区生态保育功能的空间集中度较高,农产品供给、就业与社会保障、文化传承与休闲功能则较低,4种功能空间格局具有显著规律性。② 农产品供给功能显著增强,主要分布区域向平原农区聚集;就业与社会保障高值区从内陆向沿海转移;山地丘陵生态保育功能有所增强;市辖区及周边的文化传承和休闲功能较显著。③ 农产品供给功能主导型县域集中于冀中南平原、鲁西北冲击平原、胶莱平原和辽河平原西部;社会保障主导型集中在燕山山麓平原、滨海平原、胶东半岛以及黄河三角洲;生态保育主导型集中在冀北坝上高原、燕山山地地区,以及辽西、辽东山地丘陵区和京津冀都市圈周边;文化传承与休闲功能集中于京津冀、辽中南和济南都市圈及周边;综合型位于鲁西南黄淮平原与鲁中南丘陵地区。④ 自然因素对农产品供给、就业与社会保障和生态保育功能的形成均具有显著影响;社会经济因素对4种功能的作用则具有较大差异。     

基于MODIS数据的2001—2018年中国耕地复种指数反演研究

耕地复种指数的持续稳定关乎国家粮食安全战略,实时高效地获取复种指数时空演变的详细过程信息具有重要意义。论文基于2001—2018年500 m分辨率的MODIS09A1影像数据,利用小波谱顶点的快速自动检测方法获取了全国复种指数的时空分布图,并采用Mann-Kendall检验、启发式分割算法等方法开展了全国复种指数变化形式的时空演变规律及驱动机制研究。结果表明：全国耕地复种指数稳中有升,复种指数均值从2001年的1.14上升至2018年的1.30。全国6%的耕地面积复种指数发生显著变化(约13.5万km²),相当于一个安徽省的面积。复种指数增加面积约占变化面积的2/3,复种指数下降面积约占变化面积的1/3。其中,复种指数增加的面积主要来源于黄土高原区、甘新区的休耕转为单季以及黄淮海区单季转双季,且集中在2004—2013年。2013年至今,全国复种指数仍呈增加趋势,黄淮海区单季转双季的面积保持持续增加是重要的影响因素。复种指数下降的面积主要来源于2009—2013年长江中下游平原区的双季转单季。保持黄土高原区、甘新区的耕地有效种植面积以及黄淮区耕地的双季种植面积,适当抑制长江中下游地区耕地复种指数的下降态势,对于稳定耕地复种指数、确保粮食安全具有重要意义。     

农业地域类型的识别及其演进特征——以106国道沿线典型样带区为例

构建农业地域类型的辨识指标体系,采用农用地动态度、农用地优势度、重心模型和空间自相关模型,分析1996、2000和2009年106国道沿线样带区农业地域类型的时空格局、演进特征及其驱动机制。结果表明:① 研究区农业发展的社会经济条件地域差异显著,呈现北高南低的梯度分布规律,并在样带中南部形成“低谷区”。② 农用地结构、利用程度与方式变化显著。耕地减少326.17×10³ hm²,北部快于南部地区,山地丘陵区快于平原农区;园地和林地逐渐向优势区集中,牧草地总体变化不明显;垦殖指数有所下降,耕地承载人口压力日益增加,水浇地面积比重大。③ 农业仍然是主要部门,其次为畜牧业、林业和渔业;果品、蔬菜生产在全国占据重要地位。样带区东部平原县农业优势高于西部山地丘陵县,而牧业比较优势则是西部高于东部,林业比较优势呈由南向北逐渐增强的态势,南部渔业优势突出。④ 农业投入产出效益逐年递增,且有加速趋势。⑤ 农业地域类型的形成与演变受自然资源禀赋、人口变化、经济增长、技术革新和政策体制等因素的综合影响,但各时期的主导驱动机制有所差别。     

Spatio-temporal differences and factors influencing intensive cropland use in the Huang-Huai-Hai Plain

This study developed a comprehensive system to evaluate the intensity of cropland use and evolution of cropland use in the Huang-Huai-Hai Plain. Delphi-entropy methods were adopted to determine the weight of the index, and the GeoDetector model was established to explore the influencing factors. The results are summarized as follows: (1) The intensity of inputs, degree of utilization, and production increased continuously, but the intensity of continuous conditions experienced an overall decline followed by a rebound towards the end of the study period. The number of counties with high and moderately high intensity increased by 56.8% and 14.6%, respectively, from 1996 to 2011. The number of counties with moderately low and low intensity declined by 35.9 % and 11.9 %, respectively. Areas with significant increases in intensity were mainly distributed in northeast Hebei Province, northwest Shandong Province, and north Jiangsu Province. The intensity is high in northern Jiangsu and Anhui; the output effect remained above moderate intensity mainly near Beijing, Tianjin, Tangshan, and counties in the suburbs of Shijiazhuang. (2) Natural disasters, elevation, slope, and road networks were the main factors influencing the intensity of cropland use in this region, with influence values of 0.158, 0.143, 0.129, and 0.054, respectively. Areas with moderately high and high levels of intensity were distributed in low-lying areas. Uneven distribution of precipitation, seasonal drought, and flood disasters can directly affect the stability index of croplands and reduce the intensity of cropland use. Developed road networks are associated with moderately high intensity. Our results suggest recommendations such as promoting agricultural intensification and large-scale management, promoting the construction of road networks, improving early warning systems for drought and flood disasters, and promoting moderate and intensive use of arable land, and focusing on restoration and sustainable use of cropland.     

黄淮海平原耕地集约利用时空差异及其影响因素研究（英文）

This study developed a comprehensive system to evaluate the intensity of cropland use and evolution of cropland use in the Huang-Huai-Hai Plain.Delphi-entropy methods were adopted to determine the weight of the index,and the Geo Detector model was established to explore the influencing factors.The results are summarized as follows:(1) The intensity of inputs,degree of utilization,and production increased continuously,but the intensity of continuous conditions experienced an overall decline followed by a rebound towards the end of the study period.The number of counties with high and moderately high intensity increased by 56.8% and 14.6%,respectively,from 1996 to 2011.The number of counties with moderately low and low intensity declined by 35.9 % and 11.9 %,respectively.Areas with significant increases in intensity were mainly distributed in northeast Hebei Province,northwest Shandong Province,and north Jiangsu Province.The intensity is high in northern Jiangsu and Anhui;the output effect remained above moderate intensity mainly near Beijing,Tianjin,Tangshan,and counties in the suburbs of Shijiazhuang.(2) Natural disasters,elevation,slope,and road networks were the main factors influencing the intensity of cropland use in this region,with influence values of 0.158,0.143,0.129,and 0.054,respectively.Areas with moderately high and high levels of intensity were distributed in low-lying areas.Uneven distribution of precipitation,seasonal drought,and flood disasters can directly affect the stability index of croplands and reduce the intensity of cropland use.Developed road networks are associated with moderately high intensity.Our results suggest recommendations such as promoting agricultural intensification and large-scale management,promoting the construction of road networks,improving early warning systems for drought and flood disasters,and promoting moderate and intensive use of arable land,and focusing on restoration and sustainable use of cropland.     

农牧交错区沙地景观空间格局的间隙度分析

科尔沁沙地农牧交错区典型景观空间格局的间隙度分析表明:放牧活动是造成该地区景观变化的主要原因,这一过程直接导致了半固定沙丘斑块(放牧场)在整个景观中的间隙度指数增高、面积减少;相反,半流动沙丘斑块间隙度降低,面积增大。农业生产活动对农田斑块的影响要小于牧业对半固定沙丘斑块的影响。同时研究结果还指出,尺度对空间格局的分析有较大的影响,对同一研究对象采用不同的尺度来研究,可确定两者间的相互关系。景观间隙度分析,可以为研究不同的生态学过程在景观中的扩散、转移提供必备的条件和依据。     

基于BP模型和Ward法的北京市平谷区乡村地域功能评价与分区

构建乡村地域功能评价指标体系,借助BP神经网络模型揭示平谷区“生产-生活-生态”功能分异特征;运用Ward法划分功能区,服务于平谷区乡村转型发展和功能区布局。结果表明：① 在多项功能综合作用下,平谷区基本形成了“平原地区生产功能较强、镇中心及周边村域生活功能明显、山地区以生态功能为主”的功能分布格局。② 基于评价结果和空间属性,平谷区划分为西部平原生产区、东部山地生态生产区、中部平原城市生活区、中部近郊平原生活区、东部丘陵生态生活区和北部山地生态区。其中,西部平原生产区、中部平原城市生活区、北部山地生态区是平谷三生空间功能发展的优势区域,分布相对集中。按照“强功能重优化、中等功能重提升、弱功能重改善”的原则提升乡村地域功能,促进地区均衡发展。     

西藏雅鲁藏布江中游河谷地区1830年耕地格局重建

通过收集、整理《铁虎清册》中记录的雅鲁藏布江中游河谷地区1830年的耕地税收数据,将其换算为现代耕地面积,在此基础上运用网格化模型重建出该区1 km×1 km空间分辨率的耕地格局。结果显示：① 从耕地数量分析,1830年研究区耕地面积约895 km²,其中政府占有耕地39%,贵族占有耕地31%,寺庙占有耕地29%。② 从耕地分布格局分析,研究区内耕地分布较少,只有27.4%的网格具有耕地分布,且呈分散分布状态,耕地主要分布在雅鲁藏布江干流及主要支流宽阔的河谷地区。③ 从垦殖程度分析,全区垦殖程度较低,其平均垦殖率仅有0.6%,其中垦殖率最高的地区是拉萨,平均垦殖率为6.3%;日喀则、江孜、乃东、琼结等地垦殖率均达到3%左右;工布地区和西部县区垦殖率均在1%以下,耕地垦殖率区域差异明显。     

黄淮海平原气候变化及其对耕地生产潜力的影响

利用1991年和2000年黄淮海平原气象台站的历史观测资料,分析该地区气温、降水的变化趋势,并利用农业生态地带(AEZ)模型估算黄淮海平原各农业生态区的耕地生产潜力。通过分析气温、降水与耕地生产潜力的关系,评价气候变化对耕地生产潜力的影响。研究发现,黄淮海平原耕地生产潜力与降水量、气温呈显著正相关。对各农业生态区的回归分析表明,如果气温或降水量提高10%,耕地生产潜力将分别提高3.2%与0.3%。该研究对制订应对气候变化、保护耕地与提高耕地生产潜力方面的决策具有参考价值。     

滇西北山区土地持续利用动态评价与分析--以云南省永胜县为例

以云南省永胜县为例,应用景观生态学原理,构建土地持续利用的时空耦合的综合评价指标体系,定量评价全县1996年、1999年和2001年间的土地利用可持续性动态,并构建指标贡献度与指标障碍度,定量表征各指标的相对作用强度。研究结果表明,研究时段内全县各乡镇土地利用可持续性整体均较低,相对差异大而稳定;区域土地利用系统在1999年前后发生了较大变化,偏离了土地持续利用目标;对全县各乡镇土地利用可持续性起重要贡献作用的因素主要是人口密度与土地利用程度指数,景观多样性与复种指数次之;主要障碍因素则是地均工农业总产值、粮食作物单产、景观破碎度,油料作物单产、单位面积耕地化肥使用量次之。     

基于RS、GIS的农林牧复合生态系统景观格局分析--以巴里坤湖区为例

运用景观生态学原理．借助地理信息系统,以LANDSAT TM标准假彩色合成影像数据作为主要信息源,经过图像增强处理和解译．结合各类地理统计数据,将研究区划分为7个景观类型,采用分离度、景观分维数、多样性、均匀性、破碎性、优势度等项景观指标分析了研究区的景观空间格局特征。研究结果表明：(1)该区域主要景观类型为草地景观、荒地景观,主要斑块类型为草地、戈壁、林地和耕地;(2)研究区景观破碎度较低,多样性较小,景观较完整;(3)在该区农林牧复合生态系统中,牧业占据主导地位,但由于人类活动影响的增强,平原区草地生态系统退化表现明显。