高分辨率全球地表覆盖制图及其在(可编辑)

高分辨率全球地 表 关于同志近三年现实表现材料材料类招标技术评分表图表与交易pdf视力表打印pdf用图表说话 pdf 覆盖制图及其在(可编辑) 高分辨率全球地表覆盖制图及其在 高分辨率全球地表覆盖制图及其在 全球变化研究中的应用 清 华 大 学 地 球 系 统 科 学 研 究 中 心 宫鹏 pe nggo ng@ t s i nghua .e du.c n林则徐 (1785-1851) 师夷制夷,放眼 看世界第一人 对英国侵略者的战争的困难是看不到对手,不知道前沿在哪里… 160多年后的今天我们知道前沿在哪里吗?Land cover and land use Land cover is the physical evidence on the earth surface It is spectrally unique and thus easier to be automatically identified from remotely sensed imageryLand cover and land use Land use is the human activity on land ? it is radiometrically heterogeneous and thus harder for automatic recognitionEach has different useLand use ? reflects the social functions of land such as living, production, recreation, … is therefore related to economy, politics, culture… Land cover ? determines surface radiation, runoff, matter mobility including liquid water, permeability… therefore is related to meteorology, hydrology, climatology, soil erosion, pollution dispersion ….Importance of global land cover mappingEssential variable in earth observationClimate change and atmospheric scienceCarbon cyclingHydrological modelingEcosystem servicesHabitat studiesBiodiversity 小尺度的森林砍伐、湿地损失、和 城市 化 改变 全 球 气 候 系统 旧 金 山 海 湾湿地在150 年 中的减 少 和破碎 化人类土地利用变化造 成的碳排放 Carbon Emissions from Tropical Deforestation 2000-2006 1.80 -1 1.5 Pg C y 1.60 Africa 16% total emissions 1.40 Latin America S. & SE Asia 1.20 SUM 1.00 0.80 0.60 0.40 0.20 0.00 Houghton, unpublished -1 Pg C yr 1850 1860 1870 1880 1890 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000热带雨林减少:亚玛逊流域的情况 Morton DC et al., 2006, PNAS全球变暖对海岸带 的潜在危害 The rising sea level poses risk to the most densely populated region in China. The blue color represents the low elevation coastal zones LECZ -Source: Mcgranahan et al. 2007居住区特别是城市化发展改变气候 Jin 、Dickinson 、等的研究Plain area occupies approx. 10% of China’s total terrestrialarea More than 80% of China’s population live on the plainsWarming effect on runoff, wildfire, forest change Scholze et al 2006, PNAS Lund-Potsdam -Jena GVMWhat causes the increase in global river runoff? The significant worldwide increase in observed river runoff has been tentatively attributed to the stomatal ‘‘antitranspirant’’ response of plants to rising atmospheric CO2 [Gedney N, 2006Nature 439: 835?838]When allowing for the increase in foliage area that results from increasing atmospheric CO2 levels in a global vegetation model, we find a decrease in global runoff from 1901 to 1999The elevated atmospheric CO2 concentration does not explain the estimated increase in global runoff over the last centuryChanges in mean climate, as well as its variability, do contribute to the global runoff increaseLanduse change plays an additional important role in controlling regional runoff values, particularly in the tropicsIn tropical regions, the contribution of land use change is substantially larger than that of climate change. Piao et al., 2007, PNAS ORCHIDEE modelWhat causes the increase in global river runoff? Previous reconstruction of global runoff data suggests that global river runoff increased significantly during the 20th centuryHowever, it is difficult to estimate whether this trend in runoff is caused by natural or anthropogenic factors, because the characteristics and dynamic properties of the hydrological cycle depend on many interrelated links among climate, atmosphere, soil, and vegetation dynamicsLong-term changes in runoff depend on the balance of precipitation and evapotranspiration. What about the role of impervious surface?Projected impact of climate and land-use change on global bird diversity Over the past few decades, land-use and climate change have led to substantial range contractions and species extinctions. Even more dramatic changes to global land cover are projected for this centuryMillennium Ecosystem Assessment scenarios used to evaluate the exposure of all 8,750 land bird species to projected land-cover changes due to climate and land-use change. For this first baseline assessment, stationary geographic ranges were assumed that may overestimate actual losses in geographic rangeEven under environmentally benign scenarios, at least 400 species are projected to suffer. 50% range reductions by the year 2050 over 900 by the year 2100Expected climate change effects at high latitudes are significant, species most at risk are predominantly narrow- ranged and endemic to the tropics, where projected range contractions are driven by anthropogenic land conversionsWhereas climate change will severely affect biodiversity, in the near future, land-use change in tropical countries may lead to yet greater species lossA vastly expanded reserve network in the tropics, coupled with more ambitious goals to reduce climate change, will be needed to minimize global extinctions.Jetz, et al., 2007 PLOS BiologyChanges in bird abundance in Eastern North America The abundance of birds recorded in the North American Breeding Bird Survey decreased by up to 18 percent between 1966 and 2005The abundance of US and Canadian resident species decreased by 30 percent, and that of migrants within the United States and Canada decreased by 19 percent. Land-cover changes in northern latitudes therefore seem more consequential for bird populations than those occurring in Neotropical habitats. Lower abundances were most marked for resident breeding birds that used open, edge, and wetland habitats, the environments most affected by human disturbances?particularly urban sprawl?in northern latitudesThe abundance of resident and migrant forest-dwelling birds increased with the increases seeming to follow the 20th-century expansion of forest area in northern latitudes, rather than the loss of Neotropical forestsThe geographic footprint of changes in bird abundance linked to habitat changes in North America may thus be extending southward, with negative effects on birds that use open habitats and positive effects on forest birds.Valiela and Martinetto, 2007, BioscienceLand use change UWI Wetland Forest increase decreaseCurrent status Foley, 2011, Nature According to FAO, croplands cover 1.53 billion hectares about 12% of Earth’s ice-free land, while pastures cover another 3.38 billion hectares about 26% of Earth’s ice-free land Between 1985 and 2005 the world’s croplands and pastures expanded by 154 million hectares about 3%. But this slow net increase includes significant expansion in some areas the tropics,Yield growth is slowing down 28% gain in production occurred as cropland area increased by only 2.4%, suggesting a 25%increase in yield.However, cropland area that was harvested increased by about 7% between 1985 and 2005 Using the same methods as for the 20%result, we note that yields increased by 56%between 1965 and 1985, cereal crops decreased in harvested area by 3.6% between 1985 and 2005, yet their total production increased by 29%, reflecting a 34% increase in yields per hectareOil crops increases in both harvested area 43% and yield 57%, resulting in a 125% increase in total production Fodder crop decreased Crop use Globally, only 62% of crop production on a mass basis is allocated to human food, versus 35% to animal feed which produces human food indirectly, and much less efficiently, as meat and dairy products and3% for bioenergy, seed and other industrial products. we find the land devoted to raising animals totals 3.73 billion hectares?an astonishing ,75% of the world’s agricultural land.土 地变化科学的基本内容 土地变化科学将土地覆盖和土地利用 的动态 做为一 个耦合 的人- 环 境系统来理解。其主要内容是改善我 们对土 地利用 和土地 覆盖动 态认 识及其对地球系统结构和功能的影响 与研究气候变化科学、水科学一样, 土地变 化科学 是一门 基础科 学 土地变化的驱动力是多种多样的-需 要经济 、政治 、社会 、科学 与 工程各个学科的交叉来加强驱动过程 的理解 土地变化数据和测度 土地变化分析技术 土地变化模型与预测The mismatch of research hotspots and mapping hotspotsSibley book GROMS digitize 1119 species 462 species Range map overall, breeding, wintering Seabird, terrestrial bird Clip boundary 2005 Clip elevations outside observed range DEM Clip unsuitable habitat types 2000 land cover data Global migratory bird databaseHot spots of global biodiversity The twenty-five biodiversity hotspots green Myers, et al. 2000, Nature, 403:853?858. An additional nine hotspots blue have since been added Yu et al., in preparationHot spots of using 30 meter TM/ETM+ Yu et al., in preparationInitial objectives of China’s global land cover mapping To support earth system modeling Requires substantial change in land cover classification system ? they are composites Requires processing, informing, a large number of images taken at different time and location OUR MISSION Pure cover ? cross-walkable to previous classification systems Images chosen from the greenest season ? so limited number of spectral channels Large quantities of training and testing samples Multiple ? classifier comparison 30 m global land cover map of the land areas except for Greenland and Antarctica in 2000, 2010Results so far and soon to be available Global Analyst, Global Mapper software ? based on Google Earth and ENVI Over 90,000 training samples Over 38,000 validation samples ? aiming at a global standard ? already produced insightful results 30 m global land cover map in circa 2010 ? 66% overall accuracy; although accuracies low better than any existing land cover products 250 m global land cover maps 2001, 2010 from MODIS time series data 74% overall accuracy Soon to be available ? land cover proportion maps in 1 km 2010, 10 km 2001,2010, 25 km 2001,2010, 1 degree 2001,2010 ? for ESMEastern Africa Climate Modeling Using RAMS Ge et al., 2007A new classification scheme Satisfying needs in earth system modeling Earth system models needs plant growing forms, woody plant seasonality, leaf forms, non-woody vegetation photosynthesis types C3、C4 and age, disturbance type and intensity Rough parameterization based on those global land cover types when applied in modelsUNLCCS Def Land cover type Form PFT Closure Hgt Remark 11 Post flooding or irrigated cr Cropland 1 C3/C4 Corn/Wheat 14 Rainfed croplands Cropland C3/C4 Corn/Wheat 20 Mosaic cropland/vege Crop/Vege C3/C4 50-70% 30 Mosaic vege/cropland Crop/Vege C3/C4 50-70% 40 15%-BL-EG/Semi D Fo5m Forest 2 BL EG/Dec 1 15% 5m 50 40% BL D Fo5m Forest BL D 2 40% 5m 60 15 -40% BL D Fo5m Forest BL D 15-40% 5m 70 40% NL EG Fo5m Forest NL EG 3 40% 5m 90 15-40% NL D EG Fo5m Forest BL D/EG 15-40% 5m 100 15% ML Fo 5m Forest BL/NL 15% 5m 110 MoFo/Sh 50-70%/G20-50 Fo/Shrub/Gras C3/C4 50-70% 120 MoG50-70/F/Sh20-50 Fo/Shr/Grass C3/C4 50-70% 130 15% Sh5m Shr 3 C3/C4 15% 15% G Grassland 4 C3/C4 15% Tall/S/Tundra 150 15% Vege Vege C3/C4 15% 160 40% BL Fo Reg Fl Fresh Inland fo wetl BL 40% 170 40% Semi BL EG reg Fl Sal Coastal fo wetl BL Semi D/EG 40% 180 15% vege on reg Fl or w log Marshland 5 Watered veg 4 C3/C4 15% Inund/Floa 190 Artificial urban 50% Urban 6 50% Imp/Perv/Roof/ 200 Bare Bare 7 Wd/Wt form R/G/Sd/St 210 Water Water 8 L/Rv/Riv 220 Permanent Snow/Ice Snow/Ice 9 10 classesExisting opportunitiesFROM-GLC Accuracy: 63.72% Gong et al., 2013Yu et al., in review FROM-GLC-seg Accuracy: 64.63%