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Climate change poses a challenge to countries across the world, with news media being an important source of information on the issue. To understand how and how much news media cover climate change, this study compares coverage in ten countries from the Global North and the Global South between 2006 and 2018 (N = 71,674). Based on a panel analysis, we illustrate that news media attention varies across countries and is often associated with political, scientific, and (partly) societal focusing events. Based on an automated content analysis, we also find that news media do not only cover ecological changes or climate science, but that they focus predominantly on the societal dimension of climate change: They emphasize how humans are aware of, affected by, battle, or cause climate change. Overall, the study illustrates important differences between the Global North and the Global South. While countries from the Global North cover climate change more frequently, countries from the Global South focus more on its challenges and implications for society at large, i.e., the societal dimension of climate change. 相似文献
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研究城市地表覆盖与地表温度（LST）的关系对改善城市生态环境具有重要科学意义。在Landsat TM数据支持下,利用线性光谱混合分析模型提取不透水地表信息,结合LST和地表热通量,分析不透水地表覆盖度（ISA）和LST的时空变化特征及其相互关系,探讨不透水地表对LST的影响机理。结果表明:1984—2014年北京不透水地表面积迅速增长,中覆盖度比例下降,高覆盖度比例增加;LST从市中心向郊区递减,高温区向外扩张;LST和ISA呈显著正相关,但不是简单的线性关系;ISA处于0.6~0.9时LST上升速率最快,减少ISA在此范围内的不透水地表集中分布可缓解高温区集中的现象。 相似文献
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本文简要介绍了陆地系列地球资源卫星的轨道特征，并以陆地—５号资源卫星为例，根据南山站的座标计算出该站对陆地—５号资源卫星的可观测范围及以该站为中心的卫星的覆盖区域。 相似文献
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Nengcheng Chen Jie He Wei Wang Zeqiang Chen 《International journal of geographical information science》2013,27(7):1045-1068
The OGC Web Service (OWS) schemas have the characteristics of a complex element structure, are distributed and large scale, have differences in element naming, and are available in different versions. Applying conventional matching approaches may lead to not only poor quality, but also bad performance. In this article, the OWS schema file decomposition, fragment presentation, fragment identification, fragment element match, and combination of match results are developed based on the extended FRAG-BASE (fragment-based) schema-matching method. Different versions of Web Feature Service (WFS) and Web Coverage Service (WCS) schema-matching experiments show that the average recall of the extended FRAG-BASE matching for the schemas is above 80%, the average precision reaches 90%, the average overall achieves 85%, and the matching efficiency increases by 50% as compared with that of the COMA and CONTEXT matcher. The multi-version WFS retrieval under the Antarctic Spatial Data Infrastructure (AntSDI) data service environment demonstrates the feasibility and superiority of the extended FRAG-BASE method. 相似文献
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本研究利用MODIS-NDVI产品生成中亚天山2000-2016年植被覆盖度，利用线性回归法和偏相关法分析了中亚天山植被时空变化特征及驱动因子。结果表明：中亚天山植被生长及变化趋势具有显著的区域分异性，纬度分区上，中天山和北天山西部植被覆盖度较高的草原、农田和森林在2000-2016年呈现退化趋势；南天山和北天山东部植被覆盖度较低的荒漠、草原和灌丛在同期表现出改善趋势，而中国境内的东天山与境外的西天山相比具有较低的植被覆盖度以及总体改善的变化趋势。中亚天山气候在2000-2016年显示出“暖湿化”特征，温度升高幅度（5.9%）远大于降水增加幅度（1.3%），温度、降水与植被覆盖度的显著相关比例为18.0%和42.6%，降水是中亚天山植被变化的主要气候驱动因素。以巴音布鲁克草原为代表的东天山部分草原受到过度放牧的影响而退化严重，建议加强植被退化区的生态修复与保护力度。 相似文献
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拉普捷夫海是北冰洋的边缘海和冰源地,对北冰洋的海冰变化有重要影响。通过分析AMSR-E海冰密集度数据以及NECP-DOE的风场、温度场数据,结果表明拉普捷夫海海冰在2002—2011年经历了如下过程：重冰年(2002—2004)—过渡性质年份(2005—2006) —轻冰年(2007、2009—2011),即冰情由重向轻转变。研究结果也表明拉普捷夫海的冰情轻重与融冰期长短有较好的相关性,融冰期持续时间越短,冰情越重。4个参数,包括海冰距平指数、最小海冰覆盖率、积温、风驱动指数描述了拉普捷夫海的海冰多年变化过程。海冰距平指数是时间（3—11月）平均下的海冰覆盖率距平值,定量给出了各年冰情的轻重;最小海冰覆盖率是夏季海冰的极限情况,变化范围在0.45%—48.73%,发生时间为8月底至10月上旬。积温是上一个冬季气温积累对当年冰情的影响,结果表明积温是影响当年冰情轻重的主要因素。2008年的上一个冬季经历了异常低温,造成当年的异常重冰年。风驱动指数给出了风场对海冰覆盖率变化的短期影响,与同时期其他年份相比,2006年4月、2007年9月均出现了异常强北风,一定程度上造成了2006年融冰开始时间延后、2007年夏季最小海冰覆盖率的明显偏大。 相似文献
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以2000年~2006年塔里木河下游MODIS、ETM及ASTER数据为信息源,从不同时间和空间分辨率角度分析塔里木河下游喀尔达依断面输水后NDVI时空变化规律,并在此基础上建立了研究区不同离河距离、不同时间MODIS、ETM及ASTER数据NDVI的预测模型;根据模型预测的NDVI值,使用像元二分法反演植被覆盖度,并根据当年实地调查数据对反演植被盖度进行精度验证,其平均精度达82.88%以上。以上研究结果为监测和预测塔里木河下游植被恢复提供方法借鉴和恢复趋势预测参考。 相似文献
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Experiments on surface aquaponics were carried out in simulatedly-eutrophicated cement ponds with the concentrations ofkjeldahl nitrogen (KN) 2.084 mg·l-1 and TP 0.248 mg·l-1 and without any interference from natural environment factors. On the surface of ponds rice was planted on floating-beds without soil for the purpose of collecting nutrients (N & P) from water by absorption and adsorption of rice roots. The results show that the design is not only feasible but also very effective. When the coverage of rice on floating-beds were 20%, 40% and 60%, respectively with the water depth of about 1.4 m, the removal rates of KN in water reached 29.0%, 49.8% and 58.7%, respectively and those of TP 32.1%, 42.0% and 49.1%, respectively during the test period of 84 days from tillering to maturing of rice. Other main parameters of water quality were greatly improved. The results provided a scientific basis for surface aquaponics engineering to purify eutrophicated water bodies by planting terrestrial higher plants on floating-beds. 相似文献
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植被覆盖与沙尘暴日数分布关系的探讨——-以内蒙古中西部地区为例 总被引：46，自引：4，他引：46
利用NOAA/AVHRR的NDVI数据和地面气象观测数据，以植被覆盖率和年沙尘暴日数为指标，分析了内蒙古中西部地区植被覆盖与沙尘暴分布的关系。研究结果表明，在内蒙古中西部地区，80年代沙尘暴日数的正距平与植被覆盖率的负距平、90年代沙尘暴日数的负距平与植被覆盖率的正距平是相互对应的；沙尘暴日数与植被覆盖率之间呈现负的相关关系，这种相关关系在不同地貌类型区和不同季节有所差异；沙地区的夏季（7、8、9月平均）植被覆盖率与第 2年沙尘暴日数之间的负相关最为显著。 相似文献