Investigating the Changes in Air Pollutant Emissions over the Beijing-Tianjin-Hebei Region in February from 2014 to 2019 through an Inverse Emission Method

In recent years, China has implemented several measures to improve air quality. The Beijing-Tianjin-Hebei(BTH)region is one area that has suffered from the most serious air pollution in China and has undergone huge changes in air quality in the past few years. How to scientifically assess these change processes remain the key issue in further improving the air quality over this region in the future. To evaluate the changes in major air pollutant emissions over this region, this paper employs ens...     

基于PML-V2模型和站点观测数据的植被水利用率及其趋势差异分析

运用基于Penman-Monteith公式改进得到的模型PML-V2,结合12个FLUXNET站点及其对应的叶面积指数数据,进行蒸散发分离,进而计算并分析内禀水利用率(intrinsic water use efficiency, iWUE)和冠层水利用率(canopy water use efficiency, tWUE)的趋势差异。结果表明,在站点尺度上,两种植被水利用率的变化均存在不一致性。对于落叶阔叶林(deciduous broadleaf forests, DBF),i WUE的增幅比tWUE的增幅大,而在常绿针叶林(evergreen needleleaf forests, ENF)中则相反。在DBF中,冠层导度和蒸腾作用趋势的差异可在一定程度上解释两种植被水利用率的趋势差异。通过回归分析发现森林(包括DBF和ENF)的气温和大气CO₂浓度的趋势对tWUE趋势的影响更大。研究结果表明,两种植被水利用率及其趋势存在差异。基于iWUE的研究结果并不能完全反映植被的实际水利用率变化程度,因此也不能全面反映植被与大气的相互作用。本文在站点尺度明确了全球气候变...     

基于INPHO平台对无人机空中三角测量的研究与应用

无人机因其机动灵活、成本低、具有快速响应能力成为航空摄影测量新模式,在最近几年里发展迅速,成为航空摄影测量领域引人注目的亮点。本文以无人机数据为基础,依托INPHO平台,从空中三角测量的原理、生产流程、实验数据的准备与分析、精度评定等方面进行研究,总结出无人机空中三角测量的处理流程和方法技巧,供同行参考。     

回族聚居地区新建型城镇空间增长格局研究——以宁夏吴忠市红寺堡镇为例

回族聚居地区新建型城镇一般是指西北民族地区在扶贫工程、生态移民工程、大村庄合并等补齐短板的小康社会建设中,在适宜生产生活区域建设的回族人口占比较大的新城镇,其受政府行为和城镇规划影响深刻,与普通城镇的空间自组织与他组织相结合增长过程有着明显区别。以宁夏中部扬黄新灌区吴忠市红寺堡镇为例,利用2005年、2010年和2016年3期遥感影像,运用土地利用动态度模型、空间自相关模型和核密度估算等方法,探讨回族聚居地区新建城镇的空间增长格局特征。结果表明：（1）红寺堡镇从早期居住用地占主体的用地模式逐步转变为居住-工矿仓储-公园绿地为主导的复合型用地模式,红寺堡镇作为新建城镇,城镇空间增长初期主要以公共服务与基础设施用地、商服用地、城市院落用地为主形成城市核心区,呈星型原始增长模式;随着城镇人口的增多,城镇空间增长速度加快,空间呈现轴带状及跳跃式的混合拓展增长,在城镇规划引导下,用地类型中公园与绿地等生态用地、以高层建筑为主的住宅小区和工矿仓储用地占比显著上升,用地模式逐渐向复合型用地模式转变。（2） Global Moran’s I指数研究显示,经过近10多年的城镇建设,尤其是在科学合理的城镇规划作用下,各用地类型的空间自相关在逐渐增强,空间格局呈现集聚态势;基于3次城镇规划及土地利用规划,以功能性用地的混合布局为特征,城镇用地的总体格局没有发生剧烈变化,仅在原有基础之上进行了微调,城镇空间增长趋于稳定,用地类型、用地结构比例趋于合理,新型小城镇建设成效初见端倪。（3）作为回族聚居小城镇,红寺堡镇区清真寺空间分布格局变化较小,总体呈现西南部相对密集,东北部相对稀少的特征,与各个时段内农业聚落大范围分布有密切关系;近些年镇区出现清真寺由低密度蔓延态势向高密度蔓延转变,这种变化主要受教派体系较多的回族文化特征影响,空间分布与各教派教众人口分布的随机性有较高的一致性。     

中等排放情景下中国未来不同强度降雨对总降雨贡献的区域差异（2006―2100年）

采用RCP6.0中等排放情景下2006―2100年WRF 30 km×30 km日值降雨数据,根据中国气象局颁布的降雨强度等级划分标准,探究了中国不同强度降雨及其对总降雨贡献的变化趋势的空间差异特征。结果表明：1）在雨量上,中等排放情景下2006―2100年中国不同强度降雨呈现出不同的空间分异格局。小雨和中雨自东北向西南呈“高―低―高”的三块式空间分布特征;大雨、暴雨、大暴雨和总暴雨均呈“东南高,西北低”的分异格局;特大暴雨仅东南沿海的部分地区分布较多;总降雨呈“南方高,北方次之,西北低”的空间分异格局。2）在雨量贡献率上,强降雨对总降雨的贡献率普遍存在“东南高,西北低”特征,而弱降雨对总降雨的贡献率恰恰相反;不同强度暴雨对总暴雨的贡献率也有类似分布特征。3）在雨量变化趋势上,中国不同强度降雨变化趋势呈现出不同的空间分异格局,但强降雨呈增加趋势的区域显著多于呈减少趋势的区域。4）在雨量贡献率变化趋势上,强（弱）降雨对总降雨的贡献率呈增加（减少）趋势的区域占主导,强降雨对总降雨的贡献率呈增加趋势的地区明显多于弱降雨。5）在不同强度暴雨对总暴雨贡献率的变化趋势上,大暴雨和特大暴雨对总暴雨的贡献率呈增加趋势的区域明显多于暴雨。预估结果表明,中国东部降雨在朝着极端化方向发展。     

水平衡下黄淮海平原区耕地可持续生产能力测算

为缓解黄淮海平原区地下水水位的持续下降,国家提出耕地资源休养生息的战略,而实施耕地资源休养生息的关键,是确保水平衡下的耕地资源可持续生产能力。本文从可持续理论和水平衡的条件出发,将黄淮海划分成12个自然条件、社会经济条件相对均一的农业生态区,采用不同农业生态区代表实验站限水高产的产量和管理经验,以水定产并逐步修正,得到了黄淮海平原区耕地可持续生产能力,并与现实产量对比得到产量差。结果表明：① 水平衡条件下黄淮海平原区耕地的可持续粮食生产能力为1.16亿t/年;② 可持续总产产量差为-67.85万t/年,由于限水灌溉造成的粮食产能损失为小麦331.84万t/年,玉米不存在产能损失;③ 小麦主要压产地区为黑龙港地区、鲁西平原、豫东平原以及京津唐平原,而徐淮低平原、豫东平原以及胶西黄泛平原具有一定的提产潜力。通过测算,进一步认识了黄淮海平原区耕地可持续产能状况,为区域粮食生产的合理布局以及农业限水限产提供可靠依据。     

Geographical Environment for the Safe Production of Food

Food is essential for human survival, but harmful, toxic substances in food damage and threaten human health. Food production is inseparable from the place where the food is produced; that is, from the geographical environment that consists of natural and human environments, two parts of a unified whole. China’s territory is vast and its geographical environment is complex and diverse. Food production patterns in different parts of the country vary significantly, as do local socio-economic and cultural conditions. Such differences have an enormous impact on food safety. Based on the geographical area where food is produced in China, this paper reveals the main environmental problems arising from industrial and agricultural production activities, and related risks for food safety and health. In concluding, we make some recommendations for countermeasures. The main food safety related environmental problems include the excessive application of chemical fertilizers and pesticides; high background levels of heavy metals; discharge of wastewater and heavy metals; and excessive use of additives and antibiotics in livestock and poultry breeding and aquatic products. All these issues can lead to huge risks for food safety and thus health. These are not simply scientific issues, but also political, economic and legal issues, as well as social problems that differ from region to region. Therefore, comprehensive studies are needed to identify risks to food safety and health hazards in different areas. Systematic and comprehensive risk assessments of health problems caused by changing ecosystems, environmental pollution, nutrition problems and lifestyle, and especially comprehensive risk assessments of regional environmental changes and health risks are needed. Measures based on an understanding of local conditions must be put forward to protect food safety and health, to strengthen multi-sectoral management, and to improve environmental quality     

Modeling the Warming Impact of Urban Land Expansion on Hot Weather Using the Weather Research and Forecasting Model: A Case Study of Beijing,China

The impacts of three periods of urban land expansion during 1990–2010 on near-surface air temperature in summer in Beijing were simulated in this study, and then the interrelation between heat waves and urban warming was assessed. We ran the sensitivity tests using the mesoscale Weather Research and Forecasting model coupled with a single urban canopy model,as well as high-resolution land cover data. The warming area expanded approximately at the same scale as the urban land expansion. The average regional warming induced by urban expansion increased but the warming speed declined slightly during 2000–2010. The smallest warming occurred at noon and then increased gradually in the afternoon before peaking at around 2000 LST—the time of sunset. In the daytime, urban warming was primarily caused by the decrease in latent heat flux at the urban surface. Urbanization led to more ground heat flux during the day and then more release at night, which resulted in nocturnal warming. Urban warming at night was higher than that in the day, although the nighttime increment in sensible heat flux was smaller. This was because the shallower planetary boundary layer at night reduced the release efficiency of near-surface heat. The simulated results also suggested that heat waves or high temperature weather enhanced urban warming intensity at night. Heat waves caused more heat to be stored in the surface during the day, greater heat released at night, and thus higher nighttime warming. Our results demonstrate a positive feedback effect between urban warming and heat waves in urban areas.     

ENSO与西北太平洋强TC相关关系年代际变化研究

利用美国联合台风警报中心(Joint Typhoon Warning Center,JTWC),中国气象局(China Meteorological Administration,CMA)上海台风所,日本气象厅(Japan Meteorological Agency,JMA)的台风最佳路径资料以及美国NCAR/NCEP再分析资料等,深入研究厄尔尼诺—南方涛动(El Ni1o-Southern Oscillation,ENSO)与西北太平洋强热带气旋(Tropical Cyclone,TC),即1 min最大风速大于等于114 kn相关关系的变化。结果表明,ENSO与热带西北太平洋(Western North Pacific,WNP)强TC频数之间的相关关系存在明显年代际变化。在1960—1971年期间(前一阶段),强TC年频数与Ni1o3. 4(11月—次年1月平均)相关性较弱;而在1983—2014年期间(后一阶段)两者的相关性则为强的正相关。并且强TC的年频数、生命史以及生成位置在后一阶段El Ni1o和La Ni1a年之间的差异相比前一阶段都有明显的增大。进一步分析发现:热带太平洋海温异常(Sea Surface Temperature Anomaly,SSTA)的西移是造成后一阶段Ni1o3. 4指数与强TC年频数相关性提高的关键因素。在后一阶段的El Ni1o(La Ni1a)年,SSTA的西移使得WNP东南象限的相对湿度明显增加(减少),从而有利于(不利于) TC在此象限生成。又因为位于东南象限的TC比较容易发展成强TC,因此导致后一阶段的El Ni1o(La Ni1a)年有更多(更少)的强TC在西北太平洋的东南象限生成。     

甲壳动物中的酚氧化酶原激活系统研究评价

依据８０－９０年代国际关于甲壳动物免疫机制的资料,对甲壳动物中的酚氧化酶原激活系统的研究进展予以综合评价,目的在于为中国科技工作者防治虾蟹类疾病提供参考。现有的研究表明,甲壳动物中的酚氧化酶原激活系统可被微生物多糖激尖,在激活过程中产生一系列活性物质,通过多种形式参与宿主防御反应。在甲壳动物中,与ｐｒｏＰＯ系统有关的因子正在被逐步纯化出来;ｐｒｏＰＯ可由内源蛋白酶转化成活性形式,存在调节因子调节ｐ