首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
20世纪80年代以来,人类活动加速了长江流域的土地利用变化,这对当地动植物的生境质量造成了影响,在中国生态文明建设和长江经济带发展战略不断推进的大背景下,对长江中下游地区的生境质量变化开展长时间多时段的研究具有重要的现实意义。本研究以长江中下游地区7省的土地利用覆盖数据(1980–2018年)与未来土地利用模型模拟出未来四种情景(A1B,A2,B1,B2)下的土地利用覆盖数据(2050年,2100年)为基础,借助环境服务与权衡综合评估(In VEST)模型评估了长江中下游地区的生境质量时空变化。结果表明:(1)2000–2015年,研究区的坡度(R=0.502,P <0.01)和海拔(R=0.003,P <0.05)、人口密度(R=0.299,P <0.01)、NDVI(R=0.366,P <0.01)与生境质量显著相关;(2)从1980年到2018年,研究区总面积61.93%的土地生境质量下降,38.07%的土地生境质量上升;在A2情景(人口密度大,环境技术投入少,传统能源成本高)和B2情景(中等人口密度,中等绿色技术,区域政府间缺乏合作)下,研究区的生境质量将下降;(3)长江下游的生境质量恶化程度高于中游,研究区北部的生境质量恶化程度低于南部。整体上,积极的环境保护政策是有效的,但并未根本上遏制生境质量的整体退化趋势。区域发展应加大环境保护力度,控制人口增长,鼓励绿色技术创新,在处理生态问题时,要注重省际合作。本研究可为区域野生动植物保护规划和国际上的类似流域研究提供科学参考。  相似文献   

2.
Understanding the spatial and temporal variations of cropping systems is very important for agricultural policymaking and food security assessment,and can provide a basis for national policies regarding cropping systems adjustment and agricultural adaptation to climate change.With rapid development of society and the economy,China's cropping structure has profoundly changed since the reform and opening up in 1978,but there has been no systematic investigation of the pattern,process and characteristics of these changes.In view of this,a crop area database for China was acquired and compiled at the county level for the period 1980–2011,and linear regression and spatial analysis were employed to investigate the cropping structure type and cropping proportion changes at the national level.This research had three main findings:(1) China's cropping structure has undergone significant changes since 2002;the richness of cropping structure types has increased significantly and a diversified-type structure has gradually replaced the single types.The single-crop types—dominated by rice,wheat or maize—declined,affected by the combination of these three major food crops in mixed plantings and conversion of some of their planting area to other crops.(2) In the top 10 types,82.7% of the county-level cropping structure was rice,wheat,maize and their combinations in 1980;however,this proportion decreased to 50.7% in 2011,indicating an adjustment period of China's cropping structure.Spatial analysis showed that 63.8% of China's counties adjusted their cropping structure,with the general change toward reducing the main food types and increasing fruits and vegetables during 1980–2011.(3) At the national level,the grain-planting pattern dominated by rice shifted to coexistence of rice,wheat and maize during this period.There were significant decreasing trends for 47% of rice,61% of wheat and 29.6% of maize cropping counties.The pattern of maize cropping had the most significant change,with the maize proportion decreasing in the zone from northeastern to southwestern China during this period.Cities and their surroundings were hotspots for cropping structural adjustment.Urbanization has significantly changed cropping structure,with most of these regions showing rapid increases in the proportion of fruit and vegetables.Our research suggests that the policy of cropping structural adjustment needs to consider geographical characteristics and spatial planning of cropping systems.In this way,the future direction of cropping structural adjustment will be appropriate and scientifically based,such as where there is a need to maintain or increase rice and wheat cropping,increase soybean and decrease maize,and increase the supply of fruit and vegetables.  相似文献   

3.
胡丰  张艳  郭宇  张盼盼  吕帅  张长春 《干旱区地理》2022,45(4):1125-1136
生境质量是关系人类福祉和实现可持续发展的重要基础,对区域生态保护和土地资源可持续利用具有重大意义。以渭河流域为研究对象,基于2000、2010年和2020年的土地利用数据,应用斑块生成土地利用变化模拟(Patch-generating land use simulation,PLUS)模型、生态系统服务和权衡的综合评估(Integrated valuation of ecosystem services and trade-offs,InVEST)模型预测并评价了土地利用与生境质量时空变化特征。结果表明:(1) 2000—2020年渭河流域建设用地和草地面积逐年增加,林地面积略微增长,耕地面积持续减少;2020—2050年土地利用变化趋势同2000—2020年基本一致但剧烈程度显著下降,建设用地扩张趋势减缓,耕地减少幅度下降,草地面积占比超过耕地跃居流域第一。(2) 2000—2020年流域内生境质量两极分化趋势明显,低生境质量和高生境质量区域面积有所增加,中等生境质量的面积减少,整体生境质量水平呈上升趋势;2020—2050年生境质量水平继续保持逐年上升趋势但增幅放缓,生境质量变化强度下降,低生境质量区域面积逐渐减少,中等生境质量面积保持稳定,高生境质量面积有所增长。研究结果可为渭河流域土地资源可持续利用和高质量发展提供相应科学依据和决策参考。  相似文献   

4.
Until 2015,China had established 2740 nature reserves with a total area of 1.47million km~2,covering 14.8%of China’s terrestrial land surface.Based on remote sensing inversion,ecological model simulation and spatial analysis methods,we analyzed the spatial and temporal variations of fractional vegetation coverage(FVC),net primary production(NPP),and human disturbance(HD)in habitats of typical national nature reserves(NNRs)during the first 15 years of the 21st century from 2000 to 2015.And then the three indicators were compared between different NNR types and varied climate zones.The results showed that(1)the average 5-year FVC of NNRs increased from 36.3%to 37.1%,and it improved in all types of NNRs to some extent.The annual average FVC increased by 0.11%,0.84%,0.21%,0.09%,0.11%and 0.08%in NNRs of forest ecosystem,plain meadow,inland wetland,desert ecosystem,wild animal and wild plant,respectively.(2)The NPP annually increased by 2.06 g·m~(-2),1.23 g·m~(-2),0.28 g·m~(-2) and 0.4 g·m~(-2) in NNRs of plain meadow,inland wetland,desert ecosystem and wild animal,respectively.However,it decreased by 3.45 g·m~(-2) and2.35 g·m~(-2) in NNRs of forest ecosystem and wild plant respectively.(3)In the past 15 years,besides the slight decreases in the NNRs located at the Qinghai-Tibet Plateau and the south subtropical zone,HD enhanced in most of NNRs,especially HD in the warm temperate humid zone increased from 4.7% to 5.35%.  相似文献   

5.
分析不同时期城市的生境质量变化,研究城市土地利用方式对生境质量的影响,对于区域可持续发展具有重要作用.以兰州地区为例,采用InVEST模型测评其生境质量和生境稀缺性.结果 表明:2000-2015年,研究区域边界生境存在退化迹象,生境质量分布呈现与土地利用类型格局相似的集聚特征,区域总体生境质量稳定,变化频繁且生境类型...  相似文献   

6.
归一化植被指数(NDVI)作为表征植被生长状况的关键性指标,能够有效的提供植被生长状况的信息。本研究基于1982–2015年哈萨克斯坦时间序列的GIMMS/NDVI数据,分析植被)生长的空间格局及变化趋势,研究结果表明:哈萨克斯坦自北向南分布着农田、草地、灌丛这三类主要的植被类型,呈明晰的地带性分布特征;植被指数由北到南逐渐降低,农田、草地和灌丛三类主要植被类型的NDVI均值水平依次为农田草地灌丛;1982–2015年间,NDVI呈现出先增长(1982–1992年)、再降低(1993–2007年)、然后又增长(2008–2015年)的变化趋势。NDVI显著下降的区域占土地总面积的24.0%,主要分布在西北部的农田与草地交错地带以及南部边缘的农田,草地退化面积占草地总面积的23.5%、农田退化面积占农田总面积的48.4%、灌丛退化面积占灌丛总面积的13.7%,植被改善的区域分布在中东部的农田以及农田与草地的交错带,显著提升的面积占土地总面积的11.8%。  相似文献   

7.
Mountains in western China, hosted rich biodiversity and millions of people and inhabitant with vital ecosystem services, had experienced the most serious biodiversity loss with fragile ecological problems. Even though increasing attentions had been paid to this issue, we still lacked efficient methods to assess the change of plant biodiversity at medium/large scale due to the poor data and co-existing multiple habitat types. This study proposed an integrated method combining InVEST-habitat quality model, NPP and landscape pattern indexes to analyze the spatial heterogeneity of plant biodiversity and its spatiotemporal change on raster cell scale. The results indicated that plant biodiversity service was high in Bailongjiang watershed with obvious spatial pattern variations. The land area containing higher plant biodiversity were 3161 km2, which mainly distributed in the National Nature Reserve and forestry area. While the areas with lower plant biodiversity accounted for 37.67% and mainly distributed in the valleys between Zhouqu-Wudu-Wenxian County, the valley of Minjiang in Tanchang County and alpine mountain snow-covered regions. During 1990–2010, plant biodiversity level tended to increase and the higher plant biodiversity area increased from 14.13% to 17.15% due to ecological restoration and afforestation, while plant biodiversity decreased in the area with intensive human activities, such as cultivated land, urban and rural land. The results showed that combining InVEST-habitat quality model, NPP and landscape pattern indexes can effective reveal mountain plant biodiversity change. The study was useful for plant biodiversity conservation policy-making and human activity management for the disaster-impacted mountainous areas in China.  相似文献   

8.
This study examined the spatial distribution of the continent coastline in northern China using remote sensing and GIS techniques,and calculated the fractal dimension of the coastline by box-counting method,with a time span from 2000 to 2012.Moreover,we analyzed the characteristics of spatial-temporal changes in the coastline's length and fractal dimension,the relationship between the length change and fractal dimension change,and the driving forces of coastline changes in northern China.During the research period,the coastline of the study area increased by 637.95 km,at a rate of 53.16 km per year.On the regional level,the most significant change in coastline length was observed in Tianjin and Hebei.Temporally,the northern China coastline grew faster after 2008.The most dramatic growth was found between 2010 and 2011,with an increasing rate of 2.49% per year.The fractal dimension of the coastline in northern China was increasing during the research period,and the most dramatic increase occurred in Bohai Rim.There is a strong-positive linear relationship between the historical coastline length and fractal dimension(the correlation coefficient was 0.9962).Through statistical analysis of a large number of local coastline changes,it can be found that the increase(or decrease) of local coastline length will,in most cases,lead to the increase(or decrease) of the whole coastline fractal dimension.Civil-coastal engineering construction was the most important factor driving the coastline change in northern China.Port construction,fisheries facilities and salt factories were the top three construction activities.Compared to human activities,the influence of natural processes such as estuarine deposit and erosion were relatively small.  相似文献   

9.
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   

10.
加速的城市化进程导致越来越多的耕地被占用,在耕地资源供给不足情况下高质量的农田受到巨大威胁,进而可能对中国粮食安全构成威胁。尽管已对中国耕地质量的空间格局进行了评估,但其随时间变化的情况未见报导。本研究利用MODIS的净初级生产力产品(MOD17)数据,基于发展的累积概率分布法确定耕地质量标准,以2000–2005年、2005–2010年和2010–2015年三期基于Landsat遥感的土地利用变化(LUCC)数据,得到低、中、高质量农田的空间分布,定量分析城市化占用耕地的数量和质量。结果表明,城市化占用耕地面积占耕地减少总面积的比例由2000–2005年的47.29%增加到2010–2015年的77.46%。2000年,中国耕地质量以中低产田为主,分别占全国耕地面积的40.81%和48.74%,高产田仅占10.44%。随着建设用地规模的扩大,城市化占用高产田面积在全国耕地面积中的比例从2000–2005年的9.71%上升到2010–2015年的15.63%,高产田受到严重威胁。从空间上看,该现象已由华东、华南向中西部地区转移,尤其是西北地区,其2010–2015年建设占用耕地面积中,高产田达到52.97%。本研究不仅提供了一种评价耕地质量的方法,同时揭示了城市化进程占用高质量耕地的趋势。未来占用高质量农田的趋势可能会持续,必须构建以振兴乡村为主的新型发展模式,可能是缓解土地资源紧缺情况下城市化和粮食安全矛盾的可选途径,值得土地利用规划和政府决策给予重视。  相似文献   

11.
Hengduan Mountains offer land space for a variety of ecological services. However, the sustainable development and management of land space has been challenged by increased human activities in recent years. This paper performs the spatial pattern analysis of the quantitative and structural changes of various landscapes at different altitudes, and uses the land use data in 1990, 2000, 2010 and 2015 to reveal how various land patterns have changed. The results show that, within the production-living-ecological space schema, the ecological space dominates Hengduan Mountains, while the production and living space was mainly distributed in south region. During 1990–2015, the production-living-ecological spatial changes had been gradually accelerated and the regional differences had become more prominent. The agricultural production space had continuously decreased by 1132.31 km~2, and the industrial and mining production space had rapidly increased by 281.4 km~2 during 1990–2015. The living space had steadily increased, and the ecological space had increased with fluctuations. The land space pattern in Hengduan Mountains was greatly restricted by the terrain, such as altitude and slope. The implementations of China Western Development Strategy and the Returning Farmland to Forest Program had favorably promoted the changes of land spatial pattern in Hengduan Mountains.  相似文献   

12.
人口和人均食物需求的增加对全球耕地产生了显著的影响。利用欧空局提供的精度为300m的最新土地覆被产品,文章分析了1992-2015年全球耕地的时空变化趋势和耕地转化特征。结果显示:1)在1992-2004年间全球耕地面积增长迅速,而在2004-2012年间耕地增长缓慢,2012年后耕地有缓慢减少的趋势。2)在洲尺度上,非洲耕地有一直增长的态势,而其他洲耕地都经历了耕地转型,有先增长后下降的趋势;在收入较高的国家,耕地多有下降的趋势。3)全球耕地增长的热点区域主要分布在亚马逊林地、欧亚大草原和撒哈拉沙漠边缘。全球耕地减少的中心从欧洲转移到亚洲。由于迅速的城市化,亚洲耕地扩张侵占了大量农田。  相似文献   

13.
生境质量变化监测与评价对于生物多样性保护意义重大。为探明云南省拉市海流域的生境变化情况,本文基于SPOT卫星影像提取云南拉市海流域2000年与2015年两期土地利用数据,运用InVEST模型对流域生态退化度、生境质量和生境稀缺性进行评价,采用空间统计方法定量分析了2000–2015年的空间动态变化。结果表明:在研究的15年间,拉市海地区生境退化区总体较少,数量上明显减少,生态退化度呈阶梯式下降;总体上生境质量保持良好并有所提升,少部区域生境质量降低;耕地生境稀缺性增加,人地矛盾突出。拉市海生境质量提升的原因可归结为三个方面:1)当地自2000年起实行的退耕还林政策得到了很好的落实并取得了显著成效,伐木毁林等森林破坏基本杜绝,生态环境得到了恢复;2)较高的林地占比,赋予当地较高生境适宜性本底;3)当地旅游经济的发展,使生态优势转化为经济优势,大幅提高了居民经济收入水平和生活水平;同时生态资源红利的持续发挥,增加了居民生态保护的积极性,保障了森林、湿地及珍贵动植物资源保护,使生态退化减弱,生境质量提升。同时,必须注意到当地人地矛盾的加剧。为持续减轻生态退化,促进生境质量的提升,还需推动生态经济发展,进一步提高居民收入水平,减少生产生活对第一产业的依赖,缓解人地矛盾,从而使流域经济和生态协同发展,保障可持续发展目标。  相似文献   

14.
土地生态安全问题直接威胁着区域的可持续发展,探索其时空特征有助于分析区域间土地生态格局。采用1980、2000、2010以及2019年四期天津市Landsat TM遥感影像为数据源,在Arc GIS和Geo Da等软件的支撑下,利用土地利用动态度的方法,测算研究区土地利用变化,再运用土地生态安全指数和空间自相关分析法,研究天津市各区土地生态安全的空间相关性及内部异质特征。结果表明:(1)近40年天津市土地利用变化剧烈,建设用地不断扩张,耕地、未利用地面积持续缩减;(2)土地生态安全综合水平处于高安全区,蓟州区生态安全等级最高,中心城区、滨海新区生态安全水平较低;(3)各区土地生态安全空间异质性不明显,空间集聚性较强。  相似文献   

15.
基于InVEST模型的陕北黄土高原水源涵养功能时空变化   总被引:13,自引:2,他引:11  
以陕北黄土高原为研究区,基于InVEST水源涵养功能评价模块,定量评价退耕还林还草工程背景下土地利用/覆被变化对研究区水源涵养的影响,在此基础上开展水源涵养空间分区。结果表明:① 2000-2010年,陕北黄土高原草地、灌丛和林地的面积分别增加了3204 km2、285.3 km2和122.7 km2,城镇面积增加了450.4 km2;农田、荒漠、湿地的面积分别面积减少了3984.5 km2、72.7 km2和5.2 km2。② 2000-2010年,陕北黄土高原水源涵养量整体以减少为主,中部减少最为显著,减少量在25 m3/hm2~40 m3/hm2,局部区域在40 m3/hm2以上;其他大部分区域均有0~25 m3/hm2不等的减少。③ 陕北黄土高原水源涵养功能高度重要区和极重要区的总面积为32255.1 km2,所占比例为40.5%。④ 通过陕北黄土高原水源涵养功能评价和重要性分区为生态系统的科学管理提供参考。  相似文献   

16.
Among the most devastating extreme weather events, cold surge(CS) events frequently impact northern China. It has been reported that extreme weather events will increase in the global warming context. However, the direct evidence of this hypothesis is limited. Here, we investigated the changes in frequency, number, duration, and temperature of CS events in northern China using the daily minimum temperature dataset of 331 stations from 1960 to 2016. The results indicate that the annual CS events in terms of frequency and number decreased, and the duration shortened as the starting date was later and the ending date earlier. Meanwhile, the annual CS temperature increased. In addition, spatial trends in the CS events in terms of frequency, number, and duration decreased while the CS temperature increased in most regions of northern China. We interpreted these variations as a response to global warming. However, the extreme CS events in terms of frequency, number and the earliest starting date and the latest ending date showed little change though the extreme CS temperature increased, implying climate warming had not limited extreme CS events. The adverse effect of CS events on agriculture and human health remain concerning.  相似文献   

17.
Based on the daily observation data of 824 meteorological stations during 1951-2010 released by the National Meteorological Information Center, this paper evaluated the changes in the heat and moisture conditions of crop growth. An average value of ten years was used to analyze the spatio-temporal variation in the agricultural hydrothermal conditions within a 1 km2 grid. Next, the inter-annual changing trend was simulated by regression analysis of the agricultural hydrothermal conditions. The results showed that the contour lines for temperature and accumulated temperatures(the daily mean temperature ≥0°C) increased significantly in most parts of China, and that the temperature contour lines had all moved northwards over the past 60 years. At the same time, the annual precipitation showed a decreasing trend, though more than half of the meteorological stations did not pass the significance test. However, the mean temperatures in the hottest month and the coldest month exhibited a decreasing trend from 1951 to 2010. In addition, the 0°C contour line gradually moved from the Qinling Mountains and Huaihe River Basin to the Yellow River Basin. All these changes would have a significant impact on the distribution of crops and farming systems. Although the mechanisms influencing the interactive temperature and precipitation changes on crops were complex and hard to distinguish, the fact remained that these changes would directly cause corresponding changes in crop characteristics.  相似文献   

18.
基于1980-2015年的《全国农产品成本收益资料》与《山东统计年鉴》等基础资料,以耕地利用过程中的主要粮食作物和经济作物为例,探讨了山东省耕地利用集约度及其构成的时序变化特征,并进一步分析了其主要驱动因素。结果表明:(1)1980–2015年,山东省主要农作物总集约度呈上升趋势,由919.73 Yuan hm~(–2)上升到3285.06 Yuan hm~(–2),其中经济作物多年平均集约度高于粮食作物;主要农作物的人工成本和物质成本均呈增加趋势,粮食作物的物质投入远高于人工投入,而经济作物的人工投入远高于物质投入。(2)山东省主要农作物劳动集约度呈下降趋势,由1980年的501.75 d hm~(-2)下降到2015年的161.93 d hm~(–2),粮食作物相对于经济作物劳动集约度水平低且下降速率大;而资本集约度水平不断上升,由1980年的518.33Yuanhm~(–2)上升到2015年的1159.95 Yuan hm~(–2),其中种子、农家肥、化肥、农药和排灌等增产性投入比重逐渐下降,而农业机械等省工性投入比重增长显著。(3)山东省耕地利用集约度与农业劳动力数量、人均耕地面积呈显著负相关;最主要的直接驱动因素是农作物单位成本纯收益,不过在时间响应上滞后1~3年;最主要的间接驱动因素是农业政策的改革。  相似文献   

19.
Multiple cropping index(MCI) is the ratio of total sown area and cropland area in a region,which represents the regional time intensity of planting crops.Multiple cropping systems have effectively improved the utilization efficiency and production of cropland by increasing cropping frequency in one year.Meanwhile,it has also significantly altered biogeochemical cycles.Therefore,exploring the spatio-temporal dynamics of multiple cropping intensity is of great significance for ensuring food and ecological security.In this study,MCI of Huang-Huai-Hai agricultural region with intensive cropping practices was extracted based on a cropping intensity mapping algorithm using MODIS Enhanced Vegetation Index(EVI) time series at 500-m spatial resolution and 8-day time intervals.Then the physical characteristics and landscape pattern of MCI trends were analyzed from 2000–2012.Results showed that MCI in Huang-Huai-Hai agricultural region has increased from 152% to 156% in the 12 years.Topography is a primary factor in determining the spatial pattern dynamics of MCI,which is more stable in hilly area than in plain area.An increase from 158% to 164% of MCI occurred in plain area while there was almost no change in hilly area with single cropping.The most active region of MCI change was the intersection zone between the hilly area and plain area.In spatial patterns,landscape of multiple cropping systems tended to be homogenized reflected by a reduction in the degree of fragmentation and an increase in the degree of concentration of cropland with the same cropping system.  相似文献   

20.
Phenological modeling is not only important for the projection of future changes of certain phenophases but also crucial for systematically studying the spatiotemporal patterns of plant phenology. Based on ground phenological observations, we used two existing temperature-based models and 12 modified models with consideration of precipitation or soil moisture to simulate the bud-burst date(BBD) of four common herbaceous plants—Xanthium sibiricum, Plantago asiatica, Iris lactea and Taraxacum mongolicum—in temperate grasslands in Inner Mongolia. The results showed that(1) increase in temperature promoted the BBD of all species. However, effects of precipitation and soil moisture on BBD varied among species.(2) The modified models predicted the BBD of herbaceous plants with R~2 ranging from 0.17 to 0.41 and RMSE ranging from 9.03 to 11.97 days, better than classical thermal models.(3) The spatiotemporal pattern of BBD during 1980–2015 showed that species with later BBD, e.g. X. sibiricum(mean: day of year 135.30) exhibited an evidently larger spatial difference in BBD(standard deviation: 13.88 days) than the other species. Our findings suggest that influences of temperature and water conditions need to be considered simultaneously in predicting the phenological response of herbaceous plants to climate change.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号