青藏高原若尔盖地区近期土地覆被变化

土地利用/覆被是全球变化和可持续发展研究中的重要问题之一.若尔盖位于青藏高原东北边缘,是全球变化的敏感响应地带,近年来因其沙化、湿地变化而受到广泛关注.以若尔盖地区土地覆被变化为研究对象,分别选取了1987、1996和2001年的Landsat 5 TM影像,根据野外标志解译出土地覆被类型,并采用Moran Ⅰ指数揭示其空间分布特征.结论表明,在研究时段中各种土地覆被类型具有不同程度变化,其中沼泽和沙地的变化范围分别为31.86 km2,7.83 km2,增长比较显著的是沙地、居民点及建设用地、撂荒地;不同时段的Moran I指数均为0.05,表明若尔盖近期土地覆被的分布属于随机类型的.在降水没有明显增加的背景下,气温渐次升高是若尔盖土地覆被变化的主要自然因子.研究结果揭示了整个若尔盖地区的土地覆被类型及其变化;讨论了沙化现象及其防治,对全球变化的区域响应和区域环境保护具有积极意义.     

黄河三角洲土地利用与土地覆被的质量变化

土地利用／土地覆被变化（LUCC）在全球环境变化与可持续发展研究中占有重要地位。其质量变化尤能反映人类开发活动的环境效应。运用遥感信息土地分类和植被指数提取、土壤定点采样实测和统计分析相结合的方法，研究了黄河三角洲地区数年至20余年的土地利用／土地覆被的质量变化。其在区域总体上向好的方向发展，但在内部地段间存在着差异和不平衡。盐渍土改造的任务仍然十分艰巨。地力下降的隐患不可忽视。进而分析了变化的驱动力并提出土地持续利用对策。     

流域土地覆被变化水文效应的模拟——以长江上游源头区梭磨河为例

为分析地表覆被变化的水文效应,以半分布式的地形指数模型 (TOPOMODEL) 为基础,对梭磨河流域1960~1999年逐日流量过程进行了模拟。结果表明,对于流域面积2536km² 的梭磨河流域,该模型也能取得较好的模拟结果。模拟了流域40年来气候波动和地表覆被变化对流域水文的影响。最后在4种不同的流域土地覆被情景下模拟了1960~1999年逐日径流过程。对于实际蒸散发与潜在蒸发有300多mm差距的梭磨河流域,在其它条件不变的情况下,随着流域土地覆被和冠层最大截流量的增加,冠层截流蒸发和流域总蒸发增加,植被蒸腾和土壤表面蒸发减少,土壤水分增加而流域水分含量和饱和层含水量减少。地表径流、地表以下径流、总径流减小。重现期小于20年的洪峰流量减小,但对40年一遇的洪峰流量影响很小,甚至有增加洪峰流量的作用。     

基于MODIS影像的土地覆被分类研究——以京津冀地区为例

在全球变化研究中,如何快速、准确获取土地覆被信息对该项研究有着至关重要的作用.随着遥感科学的不断发展和应用领域的深入,研究者可以利用遥感影像进行土地覆被分类研究,并且具有准确、快速、自动化等优点.本文利用MODIS数据具有的多光谱、多时相特点,以京津冀地区为例,选取2013 年全年16-day 的MOD13Q1/EVI时间序列数据、2013 年5 月份一期的MOD09Q1(1、2 波段)和MOD09A1(3-7 波段)产品,并运用时间序列谐波分析法对全年MOD13Q1/EVI 时间序列数据进行去云、去噪的平滑重建处理,使其数据更能反映物候周期性变化规律.选择谐波分析后的全年MOD13Q1/EVI 时间序列数据、MODIS数据的1-7 波段地表反射率和NDWI(归一化差异水体指数)、MNDWI(改进归一化差异水体指数)和NDSI(土壤亮度指数),构建了3 种特征变量组合方案的CART决策树,分别进行京津冀地区的土地覆被分类研究.结果表明:方案一(全年EVI 的23 个时相)、方案二(方案一+MOD09 的1-7 波段地表反射率)和方案三(方案二+MNDWI+NDSI+NDWI)的总体分类精度分别达到86.70%、89.98%、91.34%,Kappa系数分别为84.94%、88.66%、90.20%.研究表明,仅利用MODIS遥感影像自身多种分类特征和决策树方法对宏观土地覆被分类就可达到较高精度,显示了本文分类方法在实践中的可行性及MODIS数据在区域尺度土地覆被分类研究方面的优势与潜力.     

土地利用/土地覆被变化对大盈江流域径流的影响

为揭示大盈江流域土地利用/土地覆被变化对径流变化的影响,基于SWAT(Soil and Water Assessment Tool)模型,通过设置不同情景,定量分析了土地利用类型变化对流域内径流的影响。结果显示:(1)SWAT模型在大盈江流域径流模拟中具有较好的适用性,率定期的模型参数R2、Ens分别达到0.68、066,验证期的模型参数R2、Ens分别达到0.69、0.67;(2)大盈江流域月均径流量与土地利用类型关系密切:把农业用地变成林地或者草地,径流量均会减少,把林地变成草地径流量则会增加,农、林、草3种土地利用类型中产流由强到弱依次为农业用地、草地、林地。(3)2006~2015年,大盈江流域土地利用类型变化主要为农业用地和林地转化为草地,这种转变导致流域的月均径流量略有增加,增加的径流量主要是由林地转化为草地所致,且林地转化为草地引起的径流增加量强于农业用地转化为草地引起的径流减少量。     

1989-2003年中国北方土地覆被变化

The 13 provinces （autonomous regions and municipalities） in northern China are located in latitude 31°-54°N and longitude 73°-136°E including Beijing, Tianjin, Hebei, Shanxi, Inner Mongolia, Jilin, Liaoning, Heilongjiang, Shaanxi, Gansu, Ningxia, Qinghai, and Xinjiang, where environments are fragile. In recent years, the eco-environmental problems such as vegetation destruction, desertification and soil erosion etc. become serious because of climate change and unreasonable human activities. In this paper, landscape pattern and its evolution in northern China from 1989 to 2003 was investigated by the combined use of RS and GIS based on the basic theory and method of landscape ecology. Land use/cover maps of the study area in 1989, 1999 and 2003 were produced by using 1 km monthly NOAA Advanced Very High Resolution Radiometer （AVHRR） and SPOTNGT Normalized Difference Vegetation Index （NDVI） dataset from national climate bureau of China which were geo-registered to Lambert azimuthal equal-area map projection and were used in the paper. Landscape evolution in the area over the study period was investigated by two methods： （a） the changes of various landscape metrics were analyzed using the landscape structure analysis program FRAGSTATS; （b） the transition matrix of landscape patch types was calculated with the help of the RS and GIS software. The results showed that from 1989 to 2003, the landscape within the study area had undertaken a complicated evolution in landscape structure and composition. The diversity index and evenness index increased during the period, which means that the landscape pattern tended to be diversified and even. The fragmentation index of grassland, forestland and water areas also increased significantly. This showed that the distribution and structure of forestland, grassland and water areas had been changed greatly during the period, especially grassland which became more and more fragmentized, and its fragmentation index increased from 19.23% to 88.72%. The transi     

USGCRP土地覆被研究的最新动向

本文根据美国全球变化研究委员会提出的“美国全球变化研究计划”（ＵＳＧＣＲＰ）,概要介绍了土地覆被研究的目标、内容和设想。由于美国在这一领域研究中的领先地位,因此本文基本反映了国际上的最新趋势。     

基于遥感和GIS的松嫩沙地土地利用/土地覆被时空格局研究

利用1986年和2000年2期TM影像资料,建立相应的空间图形库系统,定量分析了松嫩沙地典型区近15a来土地利用数量变化,从土地利用斑块特征、斑块空间邻接关系变化和主导变化类型角度对土地利用/覆被格局进行了清晰的空间描述。结果表明,研究时段内该区土地利用量变和质变活跃。耕地面状成片、条带状延伸和斑块状空间扩展,从整体上呈现集中化特征。较大面积的草地和林地被分割、破碎化,小块盐碱化草地空间聚集与扩张。耕地与草地、草地与盐碱地空间相邻度变大,草地开垦强度增大、土地盐碱化日益严重。空间变化上表现为耕地、林地、草地和未利用地之间相互转化,以草地、林地-旱地,草地-未利用地,未利用地-旱地、水田及旱地-水田最为显著。     

梭磨河流域气候波动和土地覆被变化对径流影响的模拟研究

利用一个集总式水文模型(CHARM),模拟了不同的气候与土地覆被条件下长江上游梭磨河流域的水量平衡,定量区分气候波动和土地覆被变化对水文影响的“贡献率”。模型模拟的初步结果表明,从20世纪60年代到80年代,径流深增加了45.7mm,其中,由气候波动所引起的年平均径流深的增加占63.9%,由土地覆被变化所引起的径流深的增加占20.8%,其他条件的变化所引起的径流深的增加占15.3%。     

Simulation of land-cover change in Jing-Jin-Ji region under different scenarios of SSP-RCP

Journal of Geographical Sciences - How to simulate land-cover change, driven by climate change and human activity, is not only a hot issue in the field of land-cover research but also in the field...     

Scenarios of land cover in Eurasia under climate change

The method for surface modelling of land cover scenarios(SMLCS) has been improved to simulate the scenarios of land cover in Eurasia. On the basis of the observation monthly climatic data observed from 2127 weather stations in Eurasia during 1981–2010, the climatic scenarios data of RCP26, RCP45 and RCP85 scenarios released by CMIP5, and the land cover current data of Eurasia in 2010, the land cover scenarios of Eurasia were respectively simulated. The results show that most land cover types would generally have similar changing trends in the future, but with some difference in different periods under the three scenarios of RCP26, RCP45 and RCP85. Deciduous needleleaf forest, mixed forest, shrub land, wetlands and snow and ice would generally decrease in Eurasia during 2010–2100. Snow and ice would have the fastest decreasing rate that would decrease by 37.42% on average. Shrub land would have the slowest decreasing rate that would decrease by 5.65% on average. Water bodies would have the fastest increasing rate that would increase by 28.78% on average. Barren or sparsely vegetated land would have the slowest increasing rate that would increase by 0.76%. Moreover, the simulated results show that climate change would directly impact on land cover change in Eurasia.     

Ecosystem carbon storage under different scenarios of land use change in Qihe catchment,China

Regional land use change is the main cause of the ecosystem carbon storage changes by affecting emission and sink process.However,there has been little research on the influence of land use changes for ecosystem carbon storage at both temporal and spatial scales.For this study,the Qihe catchment in the southern part of the Taihang Mountains was taken as an example;its land use change from 2005 to 2015 was analyzed,the Markov-CLUE-S composite model was used to predict land use patterns in 2025 under natural growth,cultivated land protection and ecological conservation scenario,and the land use data were used to evaluate ecosystem carbon storage under different scenarios for the recent 10-year interval and the future based on the carbon storage module of the In VEST model.The results show the following:(1) the ecosystem carbon storage and average carbon density of Qihe catchment were 3.16×107 t and 141.9 t/ha,respectively,and decreased by 0.07×107 t and 2.89 t/ha in the decade evaluated.(2) During 2005–2015,carbon density mainly decreased in low altitude areas.For high altitude area,regions with increased carbon density comprised a similar percentage to regions with decreased carbon density.The significant increase of the construction areas in the middle and lower reaches of Qihe and the degradation of upper reach woodland were core reasons for carbon density decrease.(3) For 2015–2025,under natural growth scenario,carbon storage and carbon density also significantly decrease,mainly due to the decrease of carbon sequestration capacity in low altitude areas;under cultivated land protection scenario,the decrease of carbon storage and carbon density will slow down,mainly due to the increase of carbon sequestration capacity in low altitude areas;under ecological conservation scenario,carbon storage and carbon density significantly increase and reach 3.19×107 t and 143.26 t/ha,respectively,mainly in regions above 1100 m in altitude.Ecological conservation scenario can enhance carbon sequestration capacity but cannot effectively control the reduction of cultivated land areas.Thus,land use planning of research areas should consider both ecological conservation and cultivated land protection scenarios to increase carbon sink and ensure the cultivated land quality and food safety.     

京津冀地区不透水表面覆盖率的时空演变及其对植被的影响

基于不透水表面和MODIS增强型植被指数(EVI)数据,辅以分段线性回归、趋势分析等方法,定量分析2000—2018年京津冀不透水表面覆盖率(ISP)的时空演变及其对植被的影响。结果表明:①京津冀ISP呈显著增加的趋势,增速为0.024%/a(P<0.01)。分阶段来看,2000—2010年和2011—2018年ISP均呈显著增加趋势,增速分别为0.019%/a(P<0.01)和0.037%/a(P<0.01),后一阶段的增速快于前一阶段;②空间上,ISP快速增加的区域主要位于城市和近郊,缓慢增加和增加的区域主要位于主城区和农村;③从不同ISP区域ΔEVI的时间变化趋势来看,城区、近郊和远郊的ΔEVI均呈显著下降趋势(P<0.05)的地市分别有6个、6个和3个。主城区的ΔEVI呈显著增加趋势的地市有3个(P<0.05)。从EVI的空间变化趋势来看,显著增加的区域主要位于北京、天津等市的主城区,显著减少的区域主要位于北京、天津、石家庄等地市的近郊和远郊;④从EVI随ISP的空间变化趋势看,所有地市EVI随ISP的增加均呈显著减小的趋势(P<0.01)。...     

中国北方未来50年土地利用变化模拟

1 IntroductionLand use m odelling is a useful tool to analyze the land use cause, process and result, torecognize the im pact of land use system change on ecological environm ent,and to support theland use planning and policy (IIA SA ,1998;Costanza etal.,…     

北京市土地利用空间格局演化模拟及预测

土地利用空间格局的演化模拟可定量地从空间尺度揭示区域土地利用变化的驱动因素,是厘清未来时期内土地变化的重要途径。基于CLUE-S模型,以北京市为研究案例,结合1985、2000和2010年三期土地利用数据,运用Logistic逐步回归方法识别了北京市各种土地利用类型演化的驱动因素,对北京市土地利用空间格局进行模拟。在此基础上,基于北京市社会经济发展、土地利用规划、资源禀赋及生态保护等不同情景,对北京市2020年土地利用空间分布格局进行模拟及预测。结果表明：①不同的时期内,驱动因子对不同土地利用类型的影响呈现差异性,其中交通因素及社会经济因素对土地利用类型的转化率影响较显著,坡度对各个土地利用类型的影响较大。②通过对2010年北京市土地利用变化的模拟结果来看,Kappa指数为87.03%,说明预测结果与实际土地利用情况有较好的一致性。③预测结果显示,北京市的城市发展均表现为继续向外扩展,且以东南、东北为主要扩展方向,但扩张的程度存在差异。     

Modelling scenarios of land use change in northern China in the next 50 years

Modelling scenarios of land use change and their impacts in typical regions are helpful to investigate the mechanism between land use and ecological systems and process the land use allocation under the ecological security. A system dynamics (SD) model with the aim to modelling scenarios of land use change and assessing ecological impact in northern China in the next 50 years is developed here. The accuracy assessment with the historic data from 1990 to 2001 indicated the SD model is robust. After the different "what-if" scenarios controlled by GDP, population, market, and technology advancement were built, the different scenarios of land use change in northern China from 2000 to 2050 were simulated with their ecological impact assessed. The result suggested that such factors as GDP, population, market and technology have a strong relationship with land use structural change in northern China. It also indicated that such measures as strict controlling of population increase, importing some food to keep the supply-demand balance in the region, and improving agricultural technology will be the guarantee of regional sustainable development with fast economic growth and the obvious land use structural improvement at the same time.     

Potential of land consolidation of hollowed villages under different urbanization scenarios in China

There exists great potential of rural land consolidation in China due to the aggravated hollowed villages against the background of rapid rural-urban transformation. The paper aims to investigate the potential of rural land consolidation within four urbanization scenarios: Complete urbanization, Semi-urbanization, Urbanization in batches and prospective urbanization in 2020. Research findings show that, (1) the potentials of rural land consolidation in complete and semi-urbanization are 809.89×10⁴ hm² and 699.19×10⁴ hm² respectively while rural consolidation rates are 50.70% and 43.77%. As for the urbanization in batches and urbanization in 2020, the potentials are 757.89×10⁴ hm² and 992.16×10⁴ hm². (2) Beside Tibet and Ningxia, rural consolidation rates in most provinces are between 40% and 60%, and the land increase rates are between 3% and 12%. Significant correlation between potential of rural land consolidation and the degree of hollowed villages is also found. (3) Evident differences of potential of rural land consolidation exist across provinces. Rural consolidation rates in the East and Central provinces are higher than that in the West provinces. Villages in the developed areas have higher consolidation rates than those in the less developed areas, and villages in the plain areas tend to have higher consolidation rates than those in the mountainous areas.     

山地城市土地覆盖变化对地表温度的影响

针对山地城市复杂的城市地貌和下垫面类型,本文使用TM、DEM、ETM⁺等遥感影像资料,提取了重庆市土地利用覆盖类型;借助TM、MSS等遥感数据的红外波段,反演出1988年和2000年的地表温度。分析了重庆市近十年的土地覆盖变化及其对地表温度的影响,结果表明,在1988~2000年间,研究区土地覆盖变化明显,特别是城市土地覆盖面积有显著增加。土地覆盖类型的变化会改变地表温度的空间分布,尤其是城市土地的扩展会提高地表温度。对山地、丘陵、平坝、陡坡四种耕地的地表温度进行了深入分析与研究,结果表明:山地城市土地覆盖变化引起了植被覆盖度的变化,而植被覆盖度的变化又相应地影响了地表温度的变化,植被覆盖度每下降10%,地表温度上升0.49K。