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1.
Based on the MODIS NDVI data and Landsat TM/ETM data of 2002 and 2012, this paper extracts the planting area of winter wheat–summer maize, single spring maize, cotton and forest/fruit trees, vegetable and paddy, and made the agricultural land use map of the North China Plain(NCP). Agricultural land use area accounted for 63.32% compared to the total area of the NCP in 2002. And it increased to 65.66% in 2012, which mainly caused by the vegetables and forest/fruit trees increasing. Planting areas of winter wheat–summer maize, cotton, single spring maize, forest/fruit trees, vegetables and paddy were 5031.21×10~3, 865.90×10~3, 1226.10×10~3, 1271.17×10~3, 648.02×10~3, 216.51×10~3 ha in 2012. Rank of changes was: vegetables(+45%) forest/fruit trees(+27.4%) paddy(–23.7%) cotton(–20.4%) single spring maize(+17.3%) winter wheat–summer maize(–0.6%). In developed region like Beijing and Tianjin, planting area of crops with high economic benefit(such as fruit trees and vegetables) increased significantly. Government policies for groundwater protection caused obvious decline of winter wheat cultivation in Hebei Province. Cotton planting in Shandong Province decreased more than 200,000 ha during 2002–2012. The data products will be published in the website: http://hydro.sjziam.ac.cn/Default.aspx. To clarify the agricultural land use in the NCP will be very helpful for the regional agricultural water consumption research, which is the serious problem in the NCP.  相似文献   

2.
北京城市副中心(通州区)承接着北京中心城区的非首都核心功能,其快速建设发展亟需对区域内土地利用演变格局的科学认识。本文分析了改革开放40年来通州区土地利用演变格局,根据土地利用历史演变特征与城市发展规划目标,结合文旅发展驱动要素,运用FLUS模型模拟城镇化加速、减速和可持续发展3种情景下2035年北京城市副中心(通州区)土地利用空间分布格局。结果表明:(1)北京城市副中心(通州区)以城镇发展建设为主,1980—2010年高速城镇化阶段形成“沿六环顺运河”的城市扩张格局,2010—2020年低速城镇化阶段用地分布稳定,通州区形成从西北至东南城乡分异、土地集约化发展格局,副中心作为通州区城镇化的典型区域具有与通州整体相似的时空演变特征;(2)到2035年,3种情景间土地利用变化幅度和空间分布存在显著差异,城镇可持续发展情景下生态用地面积与分布最优,有利于实现城市可持续发展。在与三大副中心分区规划的契合程度分析中,可持续发展情景下预测模拟与市政府发布的《北京城市副中心控制性详细规划(街区层面)(2016—2035年)》(简称《规划》)用地高度契合,但文化旅游功能区和宜居生活风貌区中模拟预测与...  相似文献   

3.
三江平原东北部土地利用变化的生态效应分析   总被引:3,自引:0,他引:3  
土地利用/土地覆被变化对区域生物多样性和重要生态过程影响深刻。以1987~2000年间的Landsat/TM影像作为基本信息源,利用GIS空间分析和地统计分析功能,从景观生态学角度构建生态效应指数来反映三江平原东北部地区土地利用/土地覆被变化所带来的生态效应,并且定量评价了该区生态效应与土地利用、土壤以及土壤侵蚀之间的关系。结果表明,与1987年相比,2000年研究区水田和耕地面积都增加了2000km^2以上,毁林、毁草和将沼泽湿地开垦为耕地等人类活动导致该区生态系统更加脆弱;研究区2000年的全区平均生态效应指数比1987年高0.02;2000年,研究区中同江市的生态风险最高;土壤类型与生态效应指数的对应关系显示,泥炭土区和黑土区存在较大的生态风险;土壤侵蚀等级越大,生态效应指数越高,2000年各等级土壤侵蚀强度的生态效应指数均高于1987年。  相似文献   

4.
The geomorphological evolution of the Northeastern Tibetan Plateau(NETP)could provide valuable information for reconstructing the tectonic movements of the region.And the considerable uplift and climatic changes at here,provide an opportunity for studying the impact of tectonic and monsoon climate on fluvial morphological development and sedimentary architecture of fluvial deposits.The development of peneplain-like surface and related landscape transition from basin filling to incision indicate an intense uplift event with morphological significance at around 10–17 Ma in the NETP.After that,incision into the peneplain was not continuous but a staircase of terraces,developed as a result of climatic influences.In spite of the generally persisting uplift of the whole region,the neighbouring tectonic blocks had different uplift rates,leading to a complicated fluvial response with accumulation terraces alternating with erosion terraces at a small spatial and temporal scale.The change in fluvial activity as a response to climatic impact is reflected in the general sedimentary sequence on the terraces from high-energy(braided)channel deposits(at full glacial)to lower-energy deposits of small channels(towards the end of the glacial),mostly separated by a rather sharp boundary from overlying flood-loams(at the glacial-interglacial transition)and overall soil formation(interglacial).Pronounced incision took place at the subsequent warm-cold transitions.In addition,it is hypothesized that in some strongly uplifted blocks energy thresholds could be crossed to allow terrace formation as a response to small climatic fluctuations(10~3–10~4 year timescale).Although studies of morpho-tectonic and geomorphological evolution of the NETP,improve understanding on the impacts of tectonic motions and monsoonal climate on fluvial processes,a number of aspects,such as the distribution and correlation of peneplain and the related morphological features,the extent and intensity of tectonic movements influencing the crossing of climatic thresholds,leading to terrace development,need to be studied further.  相似文献   

5.
生物多样性保护已经从濒危物种和景观保育而越来越多转向保护与社会经济协调可持续发展。社区保护是现有保护区体系的一个有力延伸,它可以在生物多样性保护、减贫以及缓解冲突等方面具有很好的发展潜力。在政策和发展引导下,肯尼亚在过去十多年时间建立了160多个社区保护区,并取得了令人满意的成绩。本文旨在介绍肯尼亚社区保护制度的发展概要、管理体制、效果和面临的主要挑战,从而让人们可以更好的认识这个途径。从社区保护的发展中获得的思路和经验教训可以为肯尼亚和其他国家自然资源可持续利用和加强社区福祉提供有益借鉴。  相似文献   

6.
Model simulation and scenario change analysis are the core contents of the future land-use change(LUC) study. In this paper, land use status data of the Three Gorges Reservoir Region(TGRR) in 1990 was used as base data. The relationship between driving factors and land-use change was analyzed by using binary logistic stepwise regression analysis, based on which land use in 2010 was simulated by CLUE-S model. After the inspection and determination of main parameters impacting on driving factors of land use in the TGRR, land use of this region in 2030 was simulated based on four scenarios, including natural growth, food security, migration-related construction and ecological conservation. The results were shown as follows:(1) The areas under ROC curves of land-use types(LUTs) were both greater than 0.8 under the analysis and inspection of binary logistic model. These LUTs include paddy field, dryland, woodland, grassland, construction land and water area. Therefore, it has a strong interpretation ability of driving factors on land use, which can be used in the estimation of land use probability distribution.(2) The Kappa coefficients, verified from the result of land-use simulation in 2010, were shown of paddy field 0.9, dryland 0.95, woodland 0.97, grassland 0.84, construction land 0.85 and water area 0.77. So the results of simulation could meet the needs of future simulation and prediction.(3) The results of multi-scenario simulation showed a spatial competitive relationship between different LUTs, and an influence on food security, migration-related construction and ecological conservation in the TGRR, including some land use actions such as the large-scale conversion from paddy field to dryland, the occupation on cultivated land, woodland and grassland for rapid expansion of construction land, the reclamation of woodland and grassland into cultivated land, returning steep sloping farmland back into woodland and grassland. Therefore, it is necessary to balance the needs of various aspects in land use optimization, to achieve the coordination between socio-economy and ecological environment.  相似文献   

7.
Coupled hydrological and atmospheric modeling is an efficient method for snowmelt runoff forecast in large basins. We use short-range precipitation forecasts of mesoscale atmospheric Weather Research and Forecasting(WRF) model combining them with ground-based and satellite observations for modeling snow accumulation and snowmelt processes in the Votkinsk reservoir basin(184,319 km2). The method is tested during three winter seasons(2012–2015). The MODIS-based vegetation map and leaf area index data are used to calculate the snowmelt intensity and snow evaporation in the studied basin. The GIS-based snow accumulation and snowmelt modeling provides a reliable and highly detailed spatial distribution for snow water equivalent(SWE) and snow-covered areas(SCA). The modelling results are validated by comparing actual and estimated SWE and SCA data. The actual SCA results are derived from MODIS satellite data. The algorithm for assessing the SCA by MODIS data(ATBD-MOD 10) has been adapted to a forest zone. In general, the proposed method provides satisfactory results for maximum SWE calculations. The calculation accuracy is slightly degraded during snowmelt periods. The SCA data is simulated with a higher reliability than the SWE data. The differences between the simulated and actual SWE may be explained by the overestimation of the WRF-simulated total precipitation and the unrepresentativeness of the SWE measurements(snow survey).  相似文献   

8.
青藏高原东北部互助县域土地利用变化对粮食安全的影响   总被引:1,自引:0,他引:1  
中国既是一个人口大国,又是一个农业大国,粮食安全在国家安全系统中具有重要地位。青藏高原是一个高海拔的少数民族聚居区域,区域粮食安全有其独特性。互助土族自治县是青藏高原东北部主要的农业县之一,同时,又是国家商品粮建设基地和青海省粮、油、肉、蛋、禽生产基地,其土地利用变化对粮食安全的影响具有一定的典型性。利用互助土族自治县1986年土地利用现状详查数据,2000,2005年土地利用变更数据、2008年TM数据,在ERDAS及ArcGIS软件支持下分析了其土地利用变化态势并计算了该县最小人均耕地面积和耕地压力指数,对因土地利用变化引起的粮食安全问题进行分析和评估。结果表明:(1)互助县耕地总量及人均粮食产量均呈现下降趋势,这与近几年的退耕还林(草)工程、基础设施建设及人口增长相关联,而粮食单产呈现上升趋势,表明科学技术的进步在起作用。(2)从粮食生产来看,人均粮食消费水平为300 kg,互助县当前粮食生产能满足其基本需求,人均粮食消费水平为400 kg时,互助县当前粮食生产不能满足其基本需求,表明需要从区外调入粮食。(3)从耕地压力指数来看,近20年来,互助县最小人均耕地面积及耕地压力指数呈现持续增长态势。  相似文献   

9.
Increasing soil organic carbon(SOC) sequestration is not only an efficient method to address climate change problems but also a useful way to improve land productivity.It has been reported by many studies that land-use changes can significantly influence the sequestration of SOC.However,the SOC sequestration potential(SOCP,the difference between the saturation and the existing content of SOC) caused by land-use change,and the effects of land-use optimization on the SOCP are still not well understood.In this research,we modeled the effects of land-use optimization on SOCP in Beijing.We simulated three land-use optimization scenarios(uncontrolled scenario,scale control scenario,and spatial restriction scenario) and assessed their effects on SOCP.The total SOCP(0–20 cm) in Beijing in 2010 was estimated as 23.82 Tg C or 18.27 t C/ha.In the uncontrolled scenario,the built-up land area of Beijing would increase by 951 km~2 from 2010 to 2030,and the SOCP would decrease by 1.73 Tg C.In the scale control scenario,the built-up land area would decrease by 25 km~2 and the SOCP would increase by 0.07 Tg C from 2010 to 2030.Compared to the uncontrolled scenario,the SOCP in 2030 of Beijing would increase by 0.77 Tg C or 0.64 t C/ha in the spatial restriction scenario.This research provides evidence to guide planning authorities in conducting land-use optimization strategies and estimating their effects on the carbon sequestration function of land-use systems.  相似文献   

10.
Despite many studies on land degradation in the Highlands of Northern Ethiopia, quantitative information regarding long-term changes in land use/cover(LUC) is rare. Hence, this study aims to investigate the LUC changes in the Geba catchment(5142 km2), Northern Ethiopia, over 80 years(1935–2014). Aerial photographs(APs) of the 1930 s and Google Earth(GE) images(2014) were used. The point-count technique was utilized by overlaying a grid on APs and GE images. The occurrence of cropland, forest, grassland, shrubland, bare land, built-up areas and water body was counted to compute their fractions. A multivariate adaptive regression spline was applied to identify the explanatory factors of LUC and to create fractional maps of LUC. The results indicate significant changes of most types, except for forest and cropland. In the 1930 s, shrubland(48%) was dominant, followed by cropland(39%). The fraction of cropland in 2014(42%) remained approximately the same as in the 1930 s, while shrubland significantly dropped to 37%. Forests shrank further from a meagre 6.3% in the 1930 s to 2.3% in 2014. High overall accuracies(93% and 83%) and strong Kappa coefficients(89% and 72%) for point counts and fractional maps respectively indicate the validity of the techniques used for LUC mapping.  相似文献   

11.
Spatially explicit modeling techniques recently emerged as an alternative to monitor land use changes. This study adopted the well-known CLUE-S(Conversion of Land Use and its Effects at Small regional extent) model to analyze the spatio-temporal land use changes in a hot-spot in Northeast China(NEC). In total,13 driving factors were selected to statistically analyze the spatial relationships between biophysical and socioeconomic factors and individual land use types. These relationships were then used to simulate land use dynamic changes during 1980–2010 at a 1 km spatial resolution,and to capture the overall land use change patterns. The obtained results indicate that increases in cropland area in NEC were mainly distributed in the Sanjiang Plain and the Songnen Plain during 1980–2000,with a small reduction between 2000 and 2010. An opposite pattern was identified for changes in forest areas. Forest decreases were mainly distributed in the Khingan Mountains and the Changbai Mountains between 1980 and 2000,with a slight increase during 2000–2010. The urban areas have expanded to occupy surrounding croplands and grasslands,particularly after the year 2000. More attention is needed on the newly gained croplands,which have largely replaced wetlands in the Sanjiang Plain over the last decade. Land use change patterns identified here should be considered in future policy making so as to strengthen local eco-environmental security.  相似文献   

12.
精确量化高寒区域的草地地上生物量在精确量化全球碳循环方面起着非常重要的作用。本研究利用月尺度的归一化植被指数、增强型植被指数、平均空气温度、≥5℃积温、总降水、降水积温比模拟了青藏高原高寒草地地上生物量。本研究对比分析了三种多重逐步回归模型,即地上生物量与归一化植被指数和增强型植被指数的逐步回归模型,地上生物量与空气温度、积温、降水和降水积温比的逐步回归模型,地上生物量与归一化植被指数、增强型植被指数、空气温度、积温、降水和降水积温比的逐步回归模型。结果表明,在高寒草甸,归一化植被指数模拟的地上生物量与观测的地上生物量间的平均绝对误差和均方根误差分别为31.05 g m~(-2)和44.12 g m~(-2);在高寒草原,归一化植被指数模拟的地上生物量与观测的地上生物量间的平均绝对误差和均方根误差分别为95.43 g m~(-2)和131.58 g m~(-2)。在高寒草原,积温模拟的地上生物量与观测的地上生物量间的平均绝对误差和均方根误差分别为33.61g m~(-2)和48.04 g m~(-2)。在高寒草甸,植被指数和气象数据模拟的地上生物量与观测的地上生物量间的平均绝对误差和均方根误差分别为28.09 g m~(-2)和42.71 g m~(-2);在高寒草原,植被指数和气象数据模拟的地上生物量与观测的地上生物量间的平均绝对误差和均方根误差分别为35.86 g m~(-2)和47.94 g m~(-2)。因此,植被指数和气候数据同时参与的逐步回归模型比植被指数或气候数据单独参与的逐步回归模型的精度高;不同高寒草地类型的回归模型精度不同。  相似文献   

13.
利用遥感数据,相关专题地图和社会经济统计数据。在GIS的支持下,以位于中国东北农牧交错带的吉林省镇赉县作为典型研究区,探讨了东北农牧交错带土地利用变化影响生态环境演化的机制。运用马尔柯夫模型对镇赉县土地利用变化进行空间统计分析。并从景观生态格局,土地荒漠化和水环境等三方面对土地利用变化的生态环境效应进行了实证分析。  相似文献   

14.
Land use and its dynamics have attracted considerable scientific attention for their significant ecological and socioeconomic implications.Many studies have investigated the past changes in land use,but efforts exploring the potential changes in land use and implications under future scenarios are still lacking.Here we simulate the future land use changes and their impacts on ecosystem services in Northeast China(NEC) over the period of 2000–2050 using the CLUE–S(Conversion of Land Use and its Effects at Small regional extent) model under the scenarios of ecological security(ESS),food security(FSS) and comprehensive development(CDS).The model was validated against remote sensing data in 2005.Overall,the accuracy of the CLUE–S model was evaluated at 82.5%.Obtained results show that future cropland changes mainly occur in the Songnen Plain and the Liaohe Plain,forest and grassland changes are concentrated in the southern Lesser Khingan Mountains and the western Changbai Mountains,while the Sanjiang Plain will witness major changes of the wetlands.Our results also show that even though CDS is defined based on the goals of the regional development plan,the ecological service value(ESV) under CDS is RMB 2656.18 billion in 2050.The ESV of CDS is lower compared with the other scenarios.Thus,CDS is not an optimum scenario for eco-environmental protection,especially for the wetlands,which should be given higher priority for future development.The issue of coordination is also critical in future development.The results can help to assist structural adjustments for agriculture and to guide policy interventions in NEC.  相似文献   

15.
Land use and land cover change(LULCC) strongly influence regional and global climate by combining both biochemical and biophysical processes. However, the biophysical process was often ignored, which may offset the biogeochemical effects, so measures to address climate change could not reach the target. Thus, the biophysical influence of LULCC is critical for understanding observed climate changes in the past and potential scenarios in the future. Therefore, it is necessary to identify the mechanisms and effects of large-scale LULCC on climate change through changing the underlying surface, and thus the energy balance. The key scientific issues on understanding the impacts of human activities on global climate that must be addressed including:(1) what are the basic scientific facts of spatial and temporal variations of LULCC in China and comparative countries?(2) How to understand the coupling driving mechanisms of human activities and climate change on the LULCC and then to forecasting the future scenarios?(3) What are the scientific mechanisms of LULCC impacts on biophysical processes of land surface, and then the climate?(4) How to estimate the contributions of LULCC to climate change by affecting biophysical processes of land surface? By international comparison, the impacts of LULCC on climate change at the local, regional and global scales were revealed and evaluated. It can provide theoretical basis for the global change, and have great significance to mitigate and adapt to global climate changes.  相似文献   

16.
饱和水汽压亏缺是一个非常重要的模拟水循环和植被生产力的参数。青藏高原上的气象站比较稀少,这限制了饱和水汽压亏缺的精确估计。中分辨率成像光谱仪提供了蒸散数据,这为模拟饱和水汽压亏缺提供了可能。尽管如此,在青藏高原上,还没有研究利用中分辨率成像光谱仪的蒸散数据模拟饱和水汽压亏缺。因此,本研究利用中分辨率成像光谱仪的潜在蒸散数据模拟了高寒草甸、高寒草原、农田、森林和灌木2000-2012年四季的饱和水汽压亏缺。春季的均方根误差和平均绝对误差分别是0.95–2.34 hPa和0.72–1.54 hPa,夏季的的均方根误差和平均绝对误差分别是1.39–2.60 hPa和0.89–1.96 hPa,秋季的均方根误差和平均绝对误差分别是0.78–1.93 hPa和0.56–1.36 hPa,冬季的均方根误差和平均绝对误差分别是0.48–1.40 hPa和0.36–0.98 hPa。高寒草原的均方根误差和平均绝对误差分别是0.48–1.39 hPa和0.36–1.00 hPa,高寒草甸的均方根误差和平均绝对误差分别是0.58–1.39 hPa和0.44–0.90 hPa,农田的均方根误差和平均绝对误差分别是1.10–2.55 hPa和0.82–1.74 hPa,灌木的均方根误差和平均绝对误差分别是0.98–1.90 hPa和0.78–1.37 hPa,森林的分别是1.40–2.60 hPa和0.98–1.96 hPa。因此,中分辨率成像光谱仪的潜在蒸散数据可以用来模拟青藏高原的饱和水汽压亏缺,且需要考虑整合植被类型和季节。  相似文献   

17.
We initially estimated the cropland area at county level using local historical documents for the Songnen Plain(SNP)in the 1910s and 1930s.We then allocated this cropland area to grid cells with a size of 1 km×1 km,using a range of cultivation possibilities from high to low;this was based on topography and minimum distances to rivers,settlements,and traffic lines.Cropland areas for the 1950s were obtained from the Land Use Map of Northeast China,and map vectorization was performed with Arc GIS technology.Cropland areas for the1970s,1980s,1990s,2000s,and 2010s were retrieved from Landsat images.We found that the cropland areas were 4.92×104 km~2 and 7.60×10~4 km~2,accounting for 22.8%and 35.2% of the total area of the SNP in the 1910s and 1930s,respectively,which increased to 13.14×10~4 km~2,accounting for 60.9%in the 2010s.The cropland increased at a rate of 1.18×10~4km~2 per decade from the 1910s to 1970s while it was merely 0.285×10~4 km~2 per decade from the 1970s to 2010s.From the 1910s to 1930s,new cultivation mainly occurred in the central SNP while,from the 1930s to 1970s,it was mainly over the western and northern parts.This spatially explicit reconstruction could be offered as primary data for studying the effects of changes in human-induced land cover based on climate change over the last century.  相似文献   

18.
Soil organic carbon(SOC) stocks in terrestrial ecosystems vary considerably with land use types. Grassland, forest, and cropland coexist in the agro-pastoral ecotone of Inner Mongolia, China. Using SOC data compiled from literature and field investigations, this study compared SOC stocks and their vertical distributions among three types of ecosystems. The results indicate that grassland had the largest SOC stock, which was 1.5-and 1.8-folds more than stocks in forest and cropland, respectively. Relative to the stock in 0–100 cm depth, grassland held more than 40% of its SOC stock in the upper 20 cm soil layer; forest and cropland both held over 30% of their respective SOC stocks in the upper 20 cm soil layer. SOC stocks in grazed grasslands were remarkably promoted after ≥20 years of grazing exclusion. Conservational cultivation substantially increased the SOC stocks in cropland, especially in the 0–40 cm depth. Stand ages, tree species, and forest types did not have obvious impacts on forest SOC stocks in the study area likely due to the younger stand ages. Our study implies that soil carbon loss should be taken into account during the implementation of ecological projects, such as reclamation and afforestation, in the arid and semi-arid regions of China.  相似文献   

19.
以中国江苏省为例,利用1985、2008年的两期遥感影像解译获取的土地利用变化数据,按照"三生"土地利用主导功能分类,通过空间热/冷点布局的分析、区域生态环境质量指数、土地利用变化类型生态贡献率和完全分解法,定量研究近30年来江苏省土地利用变化特征及其苏南、苏中、苏北三大区域生态环境响应规律。研究表明:1)1985–2008年间江苏省土地利用变化主要表现为生产用地面积的减少,生态用地、生活用地面积的增加,苏南土地利用变化最为剧烈。2)1985年–2008苏南、苏中地区农业生产功能不断弱化,苏北的工矿生产功能比较优势明显,苏南城镇生活服务功能不断增加,苏北农村生活服务功能在弱化。3)1985–2008年间江苏省及其三大区域生态环境质量均稍有下降。苏南地区对全省生态环境变化的贡献率来的最大,苏中贡献率最小。苏南、苏中地区生态环境质量恶化主要是因为土地利用变化的驱动因子是城乡建设用地规模增加。苏北地区生态环境质量恶化主要是因为土地开发整理。三大区域农业生产用地(耕地)转换为水域生态用地(水库坑塘)是区域生态环境改善的主要因素。  相似文献   

20.
近年来,包括韩国、中国、日本在内的东亚地区的全球重要农业文化遗产数量不断增加,且未来仍将会呈持续增加态势。因此,对遗产地尤其是韩国境内遗产地的保护工作变得尤为重要。为避免农业文化遗产地粗放式开发、有效协调保护与开发的关系,解决土地利用冲突问题非常关键。本研究旨在确定农业文化遗产地可持续发展型土地利用管控措施。结果表明,公私合营、地方性法规及综合性计划对农业文化遗产地开展土地利用控制具有重要作用。  相似文献   

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