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1.
The spatially explicit reconstruction of historical land-cover datasets plays an important role in studying the climatic and ecological effects of land-use and land-cover change(LUCC). Using potential natural vegetation(PNV) and satellite-based land use data, we determined the possible maximum distribution extent of forest cover in the absence of human disturbance. Subsequently, topography and climate factors were selected to assess the suitability of land for cultivation. Finally, a historical forest area allocation model was devised on the basis of the suitability of land for cultivation. As a case study, we used the historical forest area allocation model to reconstruct forest cover for 1780 and 1940 in Northeast China with a 10-km resolution. To validate the model, we compared satellite-based forest cover data with our reconstruction for 2000. A one-sample t-test of absolute bias showed that the two-tailed significance was 0.12, larger than the significant level 0.05, suggesting that the model has strong ability to capture the spatial distribution of forests. In addition, we calculated the relative difference of our reconstruction at the county scale for 1780 in Northeast China. The number of counties whose relative difference ranged from-30% to 30% is 99, accounting for 74.44% of all counties. These findings demonstrated that the provincial forest area could be transformed into forest cover maps well using the model.  相似文献   

2.
具有空间信息的历史土地覆被数据集是研究土地覆被变化气候与生态效应的基础数据。本文在潜在植被数据和现代遥感土地利用数据的基础上,确定了土地垦殖前森林植被可能的分布范围;遴选并量化了影响我国土地宜垦性的主导因子,评估了省域尺度上土地的宜垦性;构建了以土地宜垦性为权重的历史森林覆被网格化重建模型(网格大小为10 km×10km);重建了我国东北三省1780 年和1940 年网格化的森林覆被。结果表明:基于省域森林面积数据,该方法较好地再现了历史时期森林空间格局;与2000 年遥感有林地空间数据对比分析显示,模型重建结果与遥感数据绝对误差的单样本t 检验相伴概率(双尾)为0.12,大于显著性水平0.05,表明模型重建结果与遥感数据不存在显著性差异,网格化重建方法具有较好的可行性;同时,重建结果准确性评估也表明:1780 年重建结果在县域尺度上的相对误差在-30%~30%之间的县级政区有99个,占县级政区总数(不含无值区)的74.44%,总体误差相对较小。  相似文献   

3.
清代西南地区森林空间格局网格化重建   总被引:1,自引:0,他引:1  
基于遥感土地利用数据和全球潜在植被数据,确定了中国西南地区土地垦殖前森林植被可能的分布范围,并通过量化地形(海拔、坡度)和气候生产潜力(光照、温度、水分)与农林地分布间的关系,构建了土地宜垦性评估模型和历史森林面积网格化分配模型,重建了清代西南地区5个时点、分辨率为10 km×10 km的森林空间格局。结果表明:①本文设计的森林空间格局网格化重建方法具有一定的可行性,其结果能较好地反映森林变迁历史过程的基本特征;②西南地区森林覆被率从雍正二年(1724年)的54.7%下降至宣统三年(1911年)的27.8%,其减少地区主要分布在四川盆地、云南中南部以及贵州大部;③从网格占比的变化趋势看,1724-1911年,西南地区森林覆被率小于10%的网格占比上升了约31个百分点,而覆被率大于80%的网格占比则下降了约13个百分点。  相似文献   

4.
清代西南地区森林空间格局网格化重建   总被引:1,自引:0,他引:1  
基于遥感土地利用数据和全球潜在植被数据,确定了中国西南地区土地垦殖前森林植被可能的分布范围,并通过量化地形(海拔、坡度)和气候生产潜力(光照、温度、水分)与农林地分布间的关系,构建了土地宜垦性评估模型和历史森林面积网格化分配模型,重建了清代西南地区5个时点、分辨率为10 km×10 km的森林空间格局。结果表明:①本文设计的森林空间格局网格化重建方法具有一定的可行性,其结果能较好地反映森林变迁历史过程的基本特征;②西南地区森林覆被率从雍正二年(1724年)的54.7%下降至宣统三年(1911年)的27.8%,其减少地区主要分布在四川盆地、云南中南部以及贵州大部;③从网格占比的变化趋势看,1724-1911年,西南地区森林覆被率小于10%的网格占比上升了约31个百分点,而覆被率大于80%的网格占比则下降了约13个百分点。  相似文献   

5.
A review of historical reconstruction methods of land use/land cover   总被引:2,自引:1,他引:1  
Understanding long-term human-environment interactions requires historical reconstruction of past land-use and land-cover changes. Most reconstructions have been based primarily on consistently available and relatively standardized information from historical sources. Based on available data sources and a retrospective research, in this paper we review the approaches and methods of the digital reconstruction and analyze their advantages and possible constraints in the following aspects: (1) Historical documents contain qualitative or semi-quantitative information about past land use, which also usually include land-cover data, but preparation of archival documents is very time-consuming. (2) Historical maps and pictures offer visual and spatial quantitative land-cover information. (3) Natural archive has significant advantages as a method for reconstructing past vegetation and has its unique possibilities especially when historical records are missing or lacking, but it has great limits of rebuilding certain land-cover types. (4) Historical reconstruction models have been gradually developed from empirical models to mechanistic ones. The method does not only reconstruct the quantity of land use/cover in historical periods, but it also reproduces the spatial distribution. Yet there are still few historical land-cover datasets with high spatial resolution. (5) Reconstruction method based on multiple-source data and multidisciplinary research could build historical land-cover from multiple perspectives, complement the missing data, verify reconstruction results and thus improve reconstruction accuracy. However, there are challenges that make the method still in the exploratory stage. This method can be a long-term development goal for the historical land-cover reconstruction. Researchers should focus on rebuilding historical land-cover dataset with high spatial resolution by developing new models so that the study results could be effectively applied in simulations of climatic and ecological effects.  相似文献   

6.
20世纪末中国中东部耕地扩张对表面气温影响的模拟   总被引:1,自引:0,他引:1  
张学珍  刘纪远  熊喆  张宏文 《地理学报》2015,70(9):1423-1433
利用WRF模式,通过4个21年(1980-2000年)的模拟实验,研究了20世纪末中国中东部耕地扩张对表面气温的影响。控制实验分析发现WRF模式能够捕捉温度场的空间格局,模拟与观测的季节平均温度场的相关系数为0.91~0.99(P < 0.001),但模拟温度比观测温度系统性偏低2~3 ℃。控制实验与敏感实验对比分析发现,东北区和中部区的毁林和毁草开荒具有降温效应,冬季平均降幅约为-0.41 ℃,居四季之首,主要是由地表反照率增加,净短波辐射减少,感热通量随之减少所致;东南区的毁林开荒具有升温效应,夏季温度升幅最大,平均升幅为0.14 ℃,主要原因是地表粗糙度减小,湍流减弱,热量在近地层集聚,难以扩散。农业扩张的升、降温效应主要出现在局地,对区域温度变化的影响甚微,一方面是因为农业扩张占区域面积份数甚小,另一方面是因为升、降温效应在区域平均过程中相互抵消。  相似文献   

7.
Understanding long-term human-environment interactions requires historical reconstruction of past land-use and land-cover changes. Most reconstructions have been based primarily on consistently available and relatively standardized information from historical sources. Based on available data sources and a retrospective research, in this paper we review the approaches and methods of the digital reconstruction and analyze their advantages and possible constraints in the following aspects:(1) Historical documents contain qualitative or semi-quantitative information about past land use, which also usually include land-cover data, but preparation of archival documents is very time-consuming.(2) Historical maps and pictures offer visual and spatial quantitative land-cover information.(3) Natural archive has significant advantages as a method for reconstructing past vegetation and has its unique possibilities especially when historical records are missing or lacking, but it has great limits of rebuilding certain land-cover types.(4) Historical reconstruction models have been gradually developed from empirical models to mechanistic ones. The method does not only reconstruct the quantity of land use/cover in historical periods, but it also reproduces the spatial distribution. Yet there are still few historical land-cover datasets with high spatial resolution.(5) Reconstruction method based on multiple-source data and multidisciplinary research could build historical land-cover from multiple perspectives, complement the missing data, verify reconstruction results and thus improve reconstruction accuracy. However, there are challenges that make the method still in the exploratory stage. This method can be a long-term development goal for the historical land-cover reconstruction. Researchers should focus on rebuilding historical land-cover dataset with high spatial resolution by developing new models so that the study results could be effectively applied in simulations of climatic and ecological effects.  相似文献   

8.
The reconstruction of arable land patterns over historical periods is one of critical research issues in the study of land use and land cover change (LUCC). Taking into account the continuous distribution of arable land and spatial constraints, this paper proposes a constrained cellular automata model to reconstruct historical arable land patterns. The paper describes model establishment, parameter calibration, and results validation in detail. The model was applied to Jiangsu Province, China, and was compared with a conventional spatial allocation method. The results showed that the methodology developed in this study can more objectively reflect the evolution of the pattern of arable land over historical periods, in terms of similarity with contemporary pattern, than the spatial allocation methods and can provide an effective basis for the historical study of arable land.  相似文献   

9.
Land cover change is one of the major contributors to global change, but long-term, broad-scale, detailed and spatially explicit assessments of land cover change are largely missing, although the availability of historical maps in digital formats is increasing. The problem often lies in efficiency of analyses of historical maps for large areas. Our goal was to assess different methods to reconstruct land cover and land use from historical maps to identify a time-efficient and reliable method for broad-scale land cover change analysis. We compared two independent forest cover reconstruction methods: first, regular point sampling, and second, wall-to-wall mapping, and tested both methods for the Polish Carpathians (20,000 km2) for the 1860s, 1930s and 1970s. We compared the two methods in terms of their reliability for forest change analysis, relative to sampling error, point location and landscape context including local forest cover, area of the spatial reference unit and forest edge-to-core ratio. Our results showed that the point-based analysis overestimated forest cover in comparison to wall-to-wall mapping by 1–3%, depending on the mapping period. The reasons for the differences were mainly the backdating approach and map generalisation rather than the point grid position or sampling error. When we compared forest cover trajectories over time, we found that the point-based reconstruction captured forest cover dynamics with a comparable accuracy to the wall-to-wall mapping. More broadly, our assessment showed that historical maps can provide valuable data on long-term land cover trends, and that point-based sampling can be an efficient and accurate way to assess forest area and change trends. We suggest that our point-based approach could allow land cover mapping across much of Europe starting in the 1800s. Our findings are important because they suggest that land cover change, a key component of global change, can be assessed over large areas much further back in time than it is commonly done. This would allow to truly understand path dependencies, land use legacies, and historical drivers of land cover change.  相似文献   

10.
赵赟  满志敏 《地理研究》2008,27(6):1252-1260
以安徽垦殖为例,充分考虑各种误差因素,把误差控制在一定范围的要求,借助历史学的研究方法对文献资料进行考证与鉴别,运用现代的统计科学对数据进行一致性检验与修正,尝试对太平天国战争前后安徽的垦殖变动进行量化处理,提出耕地数据重建及无资料时段垦殖率插补的可行性方法,并以此完成战争前后分县垦殖率的重建,进而利用GIS再现区域垦殖变化格局。资料检验表明,这是一种较为合理的土地利用空间格局度量方法。  相似文献   

11.
杨帆  何凡能  李美娇 《地理研究》2020,39(7):1667-1679
历史草地面积重建作为历史土地利用与土地覆被变化研究的重要组成部分,可为区域乃至全球环境变化研究提供重要的基础数据。但受研究客体特性与重建资料多寡的制约,目前无论是数量估算上还是空间格局重建上均非常薄弱。本文试图在客观把握中国西部地区历史草地变化趋势与特征的基础上,利用现代遥感土地利用数据和潜在植被数据,确定土地垦殖前草地植被潜在分布范围;并结合历史耕地网格数据,构建以间接扣减为核心的草地面积重建方法;重建甘肃、宁夏、青海和新疆等省区过去300年的草地网格数据。结果表明:土地垦殖前,案例区草地覆被率高达40.87%。受土地垦殖的影响,在过去300年草地面积呈持续减少的态势。草地面积由1661年的1.11亿 hm2下降到1980年的1.03亿 hm2,并经历了1661—1724年的急剧减少、1724—1873年的缓慢减少和1873—1980年的快速减少三个时段,草地年均减少量分别为4.76万 hm2、0.75万 hm2和3.38万 hm2。在空间上,研究时段内草地垦殖区呈现出由甘肃、宁夏向青海、新疆转移的特点。以历史文献资料和1980年遥感草地网格数据为基础,对重建的草地数据开展了可靠性评估。评估显示,重建结果能够较好的再现草地变迁过程。本文构建的重建方法可被用于中国西部地区长时段的草地面积重建。  相似文献   

12.
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%。  相似文献   

13.
中国传统农区历史耕地数据网格化方法   总被引:16,自引:3,他引:13  
建立具有空间属性的历史时期土地覆被数据集有助于更好地模拟土地覆被变化的气候 与生态效应。根据我国历史时期土地开发利用的特点, 深入分析了影响我国历史时期土地开 发利用的主导因子, 量化了海拔高度、坡度、人口分布等自然及人文要素与耕地分布的关系, 并以此为依据设计了一套将我国传统农区历史耕地数据网格化的方法与算法模型, 计算各网 格(分辨率为60 km×60 km) 耕地面积占整个农区耕地总面积的比重、以及各网格的耕地面 积与垦殖率; 同时利用基于《嘉庆重修一统志》重建的中国传统农区历史耕地资料, 采用上 述方法与算法建立了研究区内1820 年(清嘉庆二十五年) 60 km×60 km 空间尺度的耕地数据 集, 并绘制了分布图。重建结果与册载府级田亩数据的比较分析表明: 该方法与算法可以有 效地将以行政区域为统计单元的中国历史耕地数据量化为具有统一且更高空间分辨率的网格 化数据集。  相似文献   

14.
There is plenty of forests in Northeast China which contributes a lot to the conservation of water and land resources, produces timber products, and provides habitats for a huge number of wild animals and plants. With changes of socio-economic factors as well as the geophysical conditions, there are dramatic changes on the spatial patterns of forest area. In this sense, it is of great significance to shed light on the dynamics of forest area changes to find the underlining reasons for shaping the changing patterns of forest area in Northeast China. To explore the dynamics of forest area change in Northeast China, an econometric model is developed which is composed of three equations identifying forestry production, conversion from open forest to closed forest and conversion from other land uses to closed forest so as to explore the impacts on the forest area changes from demographic, social, economic, location and geophysical factors. On this basis, we employ the Dynamics of Land System (DLS) model to simulate land-use conversions between forest area and non-forest cover and the land-use conversions within the sub-classes of forest area for the period 2000–2020 under business as usual scenario, environmental protection scenario and economic growth scenario. The simulation results show that forest area will expand continuously and there exist various kinds of changing patterns for the sub-classes of forest area, for example, closed forest will expand continuously and open forest and shrub will decrease a little bit, while area of other forest will keep intact. The research results provide meaningful decision-making information for conserving and exploiting the forest resources and making out the planning for forestry production in the Northeast China region.  相似文献   

15.
中国东北地区林地面积变化的动态模拟   总被引:1,自引:0,他引:1  
There is plenty of forests in Northeast China which contributes a lot to the conservation of water and land resources, produces timber products, and provides habitats for a huge number of wild animals and plants. With changes of socio-economic factors as well as the geophysical conditions, there are dramatic changes on the spatial patterns of forest area. In this sense, it is of great significance to shed light on the dynamics of forest area changes to find the underlining reasons for shaping the changing patterns of forest area in Northeast China. To explore the dynamics of forest area change in Northeast China, an econometric model is developed which is composed of three equations identifying forestry production, conversion from open forest to closed forest and conversion from other land uses to closed forest so as to explore the impacts on the forest area changes from demographic, social, economic, location and geophysical factors. On this basis, we employ the Dynamics of Land System (DLS) model to simulate land-use conversions between forest area and non-forest cover and the land-use conversions within the sub-classes of forest area for the period 2000–2020 under business as usual scenario, environmental protection scenario and economic growth scenario. The simulation results show that forest area will expand continuously and there exist various kinds of changing patterns for the sub-classes of forest area, for example, closed forest will expand continuously and open forest and shrub will decrease a little bit, while area of other forest will keep intact. The research results provide meaningful decision-making information for conserving and exploiting the forest resources and making out the planning for forestry production in the Northeast China region.  相似文献   

16.
中国土地利用变化及其影响的空间建模分析   总被引:53,自引:10,他引:53  
通过 GIS建模 ,本文分析了我国土地利用的变化与其影响因子之间的相互作用关系 ,并着重对耕地的变化及其空间分布进行了模拟。研究发现 ,土地利用的变化主要是自然与经济因素综合作用的结果 ,并且区分不同的规模尺度与不同的区域类型 ,将对提高土地利用空间变化模型的精度有着重要的影响。  相似文献   

17.
Recent studies have demonstrated the importance of LUCC change with climate and ecosystem simulation, but the result could only be determined precisely if a high-resolution underlying land cover map is used. While the efforts based satellites have provided a good baseline for present land cover, what the next advancement in the research about LUCC change required is the development of reconstruction of historical LUCC change, especially spatially-explicit historical dataset. Being different from other similar studies, this study is based on the analysis of historical land use patterns in the traditional cultivated region of China. Taking no account of the less important factors, altitude, slope and population patterns are selected as the major drivers of reclamation in ancient China, and used to design the HCGM (Historical Cropland Gridding Model, at a 60 km×60 km resolution), which is an empirical model for allocating the historical cropland inventory data spatially to grid cells in each political unit. Then we use this model to reconstruct cropland distribution of the study area in 1820, and verify the result by prefectural cropland data of 1820, which is from the historical documents. The statistical analyzing result shows that the model can simulate the patterns of the cropland distribution in the historical period in the traditional cultivated region efficiently.  相似文献   

18.
中国历史时期土地覆被数据集地理空间重建进展评述   总被引:3,自引:0,他引:3  
重建长时间序列具有空间属性的土地覆被数据集,对研究历史时期土地利用/土地覆被变化及其气候和生态效应具有重要意义。近年来,国内外学者就定量重建中国区域历史土地覆被数据集进行了积极探索。但由于历史时期土地利用数据来源多元、重建方法多样、验证方式各异等原因,不同学者的重建结果迥异,其中重建方法是导致差异形成的重要原因之一。本文从重建思路、假设和方法、结果验证等方面对覆盖中国区域的主要空间数据集进行了综合评述,结果表明:①基于历史记录的还原法和基于地理空间模型的重建法是历史土地覆被空间重建的主要方法,而根据建模过程,后者又可进一步分为“自上而下”的配置模型和“自下而上”的演化模型法。②基于数量重建进行空间重建是当前历史土地覆被数据集重建的主流,在缺少充分、客观历史数据的条件下,对基础数据、分布控制因素和限制因子进行合理假设是取得合理结果的重要条件。③为提高研究成果的解释力,需要对重建结果进行检验,直接验证法虽较为准确,但受时空尺度限制,具有显著的局限性,间接验证法可作为有效的补充。  相似文献   

19.
基于遥感和GIS的中国20世纪90年代毁林开荒状况分析   总被引:10,自引:0,他引:10  
毁林开荒过程是一种林地变为耕地的土地利用变化过程,可以通过遥感和GIS技术对这一过程进行监测。本文通过覆盖全国的TM影像数据,对20世纪90年代林地转为耕地的面积及其空间分布进行分析,从而对全国毁林开荒过程进行遥感监测。结果表明,该时期有17630km2的林地被开垦为耕地。不同面积等级的开垦过程在不同流域分布也不同:面积小于10hm2和介于10~100hm2的被开垦林地较广泛地分布于各大流域;而面积介于100~1000hm2的被开垦林地主要分布于松辽流域、黑龙江流域和东北东部流域、长江流域、珠江流域和云南省所在流域;大于1000hm2的被开垦林地则几乎全部分布于松辽流域、黑龙江流域和东北东部流域。坡度大于3°的毁林开荒地面积占总面积的295%;对土壤侵蚀背景的分析表明,土壤侵蚀强度以微度和轻度为主  相似文献   

20.
清代中期江苏省土地利用格局网格化重建   总被引:5,自引:2,他引:3  
潘倩  金晓斌  周寅康 《地理学报》2015,70(9):1449-1462
针对当前历史土地利用空间重建研究多基于单一地类且空间分辨率较低的特征,提出较高分辨率全地类土地利用空间重建方法。以1820年为时间断面,以现代江苏省域为研究区,以历史文献记载、历史地理学研究成果、现代统计数据、自然环境数据等为支撑,将土地利用类型划分为耕地、聚落用地(含城镇用地、农村居民点用地)、水域和其他用地(含林草地及未利用地),考虑区域自然资源和社会经济特征,提出理论假设,对府级耕地、城镇用地、农村居民点用地数量进行修正;沿用以现代土地利用格局为基础反演历史土地利用格局的基本思路,从人地关系角度出发,采用治所邻近度分析、综合评价等方法重建了1820年100 m×100 m空间格网下的江苏省土地利用格局,同时,通过不同地理分区统计及降尺度对比间接验证等分析了重建结果。结果表明:① 1820年江苏省耕地、城镇用地、农村居民点用地、水域用地及其他用地面积分别占区域总面积的48.49%、4.46%、0.16%、15.03%和31.86%;② 1820年研究区内土地垦殖率较高,但建设用地比率较低,受人口分布、地形及河网密度等影响,不同地理分区土地利用差异较为显著;③ 农村居民点用地及耕地的降尺度分析结果均呈显著线性正相关,在一定程度上表明研究结果具有合理性。  相似文献   

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