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| 1 | The first all-season sample set for mapping global land cover with Landsat-8 data显示文摘We report the world's first all-season training and validation sample sets for global land cover classification with Landsat-8 data.Prior to this,such samples were only available at a single date primarily from the growing season.It is unknown how much limitation such a single-date sample has to mapping global land cover in other seasons of the year.To answer this question,we selected available Landsat-8 images from four seasons and collected training and validation samples from them.We compared the performances of training samples in different seasons using Random Forest algorithm.We found that the use of training samples from any individual season would result in the best overall classification accuracy when validated by samples in the same season.The global overall accuracy from combined best seasonal results was 67.2% when classifying the 11 Level-1 classes in the Finer Resolution Observation and Monitoring of Global Land Cover(FROM-GLC) classification system.The use of training samples from all seasons(named all-season training sample set hereafter) produced an overall accuracy of 67.0%.We also tested classification within 10° latitude 60° longitude zones using all-season training subsample within each zone and obtained an overall accuracy of 70.2%.This indicates that properly grouped subsamples in space can help improve classification accuracies.All the results in this study seem to suggest that it is possible to use an all-season training sample set to reach global optimality with universal applicability in classifying images acquired at any time of a year for global land cover mapping. | Congcong Li Peng Gong Jie Wang Zhiliang Zhu Gregory S. Biging Cui Yuan Tengyun Hu Haiying Zhang Qi Wang Xuecao Li Xiaoxuan Liu Yidi Xu Jing Guo Caixia Liu Kwame O. Hackman Meinan Zhang Yuqi Cheng Le Yu Jun Yang Huabing Huang Nicholas Clinton | 2017 | Science Bulletin2017，62，7： | 21 |
| 2 | Urban growth models: progress and perspective显示文摘城市的生长模型被开发了并且广泛地采用了在周围的环境上学习城市的扩大和它的影响。这些模特儿能在发展情形的城市的决策或分析被雇用。在这份报纸,我们提供城市的生长模型的系统的评论,包括城市的模型和联系理论和不同模型和他们的应用程序的普通框架的进化。城市的生长的三个典型的班也就是,为陆地使用 / 交通模型,细胞的自动机(CA ) 模型和基于代理人的模型建模,被介绍。他们的关系被解释,就他们的建模机制,数据要求和应用程序规模而言。基于广泛地利用的城市的 CA 模型,我们为改进建议了四个观点包括基本空间单位的调整,时间的上下文,支持模型比较的公共平台,和情形的加入分析。新机会(例如,开的社会数据和综合评价当模特儿) 出现了帮助模型开发和申请。 | Xuecao Li P. Gong | 2016 | Science Bulletin2016，61，21： | 15 |
| 3 | Long-term surface water changes and driving cause in Xiong'an,China:from dense Landsat time series images and synthetic analysis显示文摘China's government statement recently reported the plan of constructing Xiong'an New Area, which aims to phase out some extra capital functions from Beijing and to explore an innovative urban development mode with the priority in eco-environmental protection. The New Area is located in the semi-arid North China Plain(NCP) and is home to NCP's largest natural freshwater wetland, Baiyangdian Lake. A comprehensive realization of surface water dynamics would be crucial for policy-makers to outline a sustainable environment development strategy for New Area. In this study, we used a total of 245 time slices of cloud-free Landsat images to document the continuous changes of water bodies within Xiong'an City during 1984-2016 and to provide detailed evidence of water presence and persistency states and changes under the influences of climate change and human actions. Our results reveal that the New Area water body areas varied dramatically during the past 33 years, ranging from 0.44 km^2 in April 1988 to317.85 km^2 in February 1989. The change of surface water area was not characterized by a monotonically decreasing tendency. The evolution processes can be divided into four sub-stages: the first extreme desiccation in mid-1980 s, the wet stage with the most extensive inundation areas and strong inter-annual fluctuations from late-1988 to late 1999, another desiccation stage in early 2000 s, and the overall recovering stage between 2007 and 2016. We also mapped the maximum water inundation extents and frequencies of all-season, pre-wet season(February-May) and post-wet season(September-December) for the 33 years and different sub-periods. Although there is good agreement between time series of surface water area evolution in the New Area and station-based precipitation and evaporation variations, multiple lines of evidences reviewed in previous research indicate that the degraded Baiyangdian Lake was also tightly associated with human activities from various aspects, including dam construction, groundwater extraction, agricultural irrigation, etc. We highlighted the current status of exploring the driving mechanism of surface water changes and existing problems, and then offer recommendations. | Chunqiao Song Linghong Ke Hang Pan Shengan Zhan Kai Liu Ronghua Ma | 2018 | Science Bulletin2018，63，11： | 6 |
| 4 | A spatialized digital database for all bird species in China显示文摘The lack of refined spatial detail on bird distribution in China has hindered further research due to the large geographic unit(provincial level) in existing national bird distribution data. Based on multi-source bird distribution data, we built a more spatially detailed distribution database for every bird species(1,371 species) in China, covering 2,908 counties. The sources on bird distribution are grouped into six categories: Handbooks, Literature; Fauna, Avifauna; Paper; Citizen Science data by ornithologists or birders; GPS tracing; and Website data. The database contains the following records: taxonomy, distribution data, suspicious species information, and data sources. Our database recorded 835 species(61%) appearing outside the distribution range previously known. The use of provincial boundaries as the smallest geographical unit has created misleading distribution results due to geographic aggregation for most species. The new database was built based on increased observational frequency and individuals observed in previously undetected areas particularly in Western China and towards higher altitudes and latitudes. They coincided with the discovery of the range expansion of some waterfowls into Xinjiang. The dataset provides a new base for Chinese and international ornithology studies, especially for those requiring more detailed distribution information for many taxa and large-scale regional research. | Shuang Dai Duole Feng Karen Kie Yan Chan Peng Gong Bing Xu | 2019 | Science China(Life Sciences)2019，62，5： | 2 |
| 5 | Ten years after Hurricane Katrina: monitoring recovery in New Orleans and the surrounding areas using remote sensing显示文摘Remote sensing data have been widely used in pre-hazard prevention/preparation, emergency response and post-hazard recovery monitoring. Hurricane Katrina caused serious damage to the environment, society and economy in the southern United States in 2005. On the 10 th anniversary of Hurricane Katrina, we monitored the recovery process in New Orleans and the surrounding area based on remote sensing. Results from multi-source remote sensing data indicated that the average vegetation conditions of the affected areas have not fully recovered compared with the pre-disaster conditions, especially in the hurricane's landfall area. Analysis from moderate resolution Landsat data showed that many civil engineering works have been undertaken in the city of New Orleans to prevent future disasters. Frequent observation using highresolution images recorded the progress of some of these civil construction projects(e.g. the 17 th Street Canal pumping station) in New Orleans. In this case study, we illustrated the capabilities of remote sensing techniques in recovery monitoring following a natural disaster. International/institutional cooperation is suggested to improve Earth observation capability in hazard monitoring. More Chinese Earth observation data are expected to be used in international monitoring. | Xuecao Li Le Yu Yidi Xu Jun Yang Peng Gong | 2016 | Science Bulletin2016，61，18： | 2 |
| 6 | 滦河上游——白枕鹤西部种群的重要停歇地显示文摘白枕鹤(Grus vipio)为国家Ⅱ级重点保护野生动物,被IUCN列为易危(VU)物种。白枕鹤西部种群繁殖于中蒙俄交界处的达乌尔地区,数量呈下降趋势。我们于2017–2018年在蒙古国东部给白枕鹤西部种群的50只个体佩戴了GPS-GSM跟踪设备。截至2019年5月,获得春季和秋季迁徙路径各48条。分析结果显示:春季91.67%和秋季72.91%的跟踪个体在滦河上游(河北省沽源–内蒙古正蓝旗–多伦区域)停歇,春季停留时间36.16±15.00天、秋季20.26±11.08天,分别占春季和秋季迁徙时间的75%和67%,确定了这一区域是西部种群迁徙途中最重要的停歇地。迁徙路线栖息地选择模型结果显示,白枕鹤常在距离湖泊较近(<210 km)、海拔1,200–1,500 m,且坡度小(<1°)的区域停歇。而滦河上游和整条迁徙路线停歇位点比较的模型结果显示,滦河上游停歇地的海拔1,200–1,500 m与整条迁徙路线栖息地选择模型的结果一致;此外这个区域离河流更近(<70km),不仅有湿地和水体的栖息环境,还有草地和农田可供觅食和栖息。保护空缺分析发现滦河上游现有四处保护地,但在保护地内的迁徙停歇点不超过总位点的1.63%。综上,我们建议将滦河上游整体纳入保护地体系进行管理,为这一受胁物种及其栖息地管理和保护提供可靠保障。 | 郎雪敏 Gankhuyag Purev-Ochir Oyunchimeg Terbish Dashdorj Khurelbaatar Baasansuren Erdenechimeg Amarkhuu Gungaa 宓春荣 郭玉民 | 2020 | 生物多样性2020，28，10： | 1 |
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