基于Supermap Objects的区域生态环境监测鹰眼功能的实现

介绍了以Supermap Objects为基础开发的用于城市生态监测的地理信息系统的空间信息查询鹰眼功能可研究开发及实现.     

土地利用类型与水分亏缺的风险程度关系——以北方农牧交错带黄土高原区为例

在北方农牧交错带植被重建中适宜乔、灌、草种生态区划的基础上,以该区域黄土高原区作为研究区,结合该区1989和1999两年的土地利用分类图,通过计算区域缺水指数及对其分级,探讨了缺水指数在时间和空间上的变化规律,分析了耕地、林地、草地等该区主要土地利用类型在时间和空间上与缺水指数的关系。在此基础上,构建水分亏缺风险指数(RiskIndexofWaterDeficit),从研究区整体和各生态分区两个尺度上探讨了不同土地利用类型的RIWD时空分异。得出如下结论:①1989～2000年,研究区缺水指数均在中度以上,其变化幅度有逐年减少的趋势;②对比1989年和1999年两年的缺水指数,区域整体缺水状况有所缓解,但各生态分区内的缓解程度在空间上仍存在差异;③从研究区整体而言,各土地利用类型的水分亏缺风险指数逐渐减少,依次为林地、耕地、草地;④因各生态分区内的地理特征包括水分状况存在变化,故各土地利用类型的水分亏缺风险程度排列顺序与区域整体有所不同。     

Assessment of emissions data for the Toronto region using aircraft-based measurements and an air quality model

An aircraft-based measurement campaign was conducted during the summer of 1996 in the vicinity of Toronto, Canada. The objective of the campaign was to assess the errors in a particular emission inventory used by three-dimensional air quality models. Measurements of NO₂ and hydrocarbons were made both upwind and downwind of Toronto, on days with strong synoptic-scale flow from a west to northerly direction. The chemical composition of the background airmass on these days was typical of unpolluted continental air. Measurements have been compared with the output from an on-line air quality model (MC2-AQ) run at 5 km resolution and suggest that emissions of NO_x from Toronto are well described in the emission database, though evidence that NO_x emissions are underestimated for suburban regions surrounding Toronto was found. In general, no significant underestimation of hydrocarbon emissions was found, though emissions of the model propane species, which includes acetylene and benzene, was underestimated by at least a factor of two.     

Global-scale environmental transport of persistent organic pollutants

In order to realistically simulate both chemistry and transport of atmospheric organic pollutants, it is indispensable that the applied models explicitly include coupling between different components of the global environment such as atmosphere, hydrosphere, cryosphere and soil system. A model with such properties is presented.

The atmospheric part of the model is based on the equations in a general contravariant form which permits easy changes of the coordinate system by redefining the metric tensor of a specifically employed coordinate system. Considering a need to include explicitly the terrain effects, the terrain following spherical coordinate system is chosen from among many possible coordinate systems. This particular system is a combination of the Gal-Chen coordinates, commonly employed in mesoscale meteorological models, and the spherical coordinates, typical for global atmospheric models.

In addition to atmospheric transport, the model also simulates the exchange between air and different types of underlying surfaces such as water, soil, snow, and ice. This approach permits a realistic representation of absorption and delayed re-emission of pollutants from the surface to the atmosphere and, consequently, allows to capture hysteresis-like effects of the exchange between the atmosphere and the other components of the system. In this model, the most comprehensive numerical representation of the exchange is that for soil. In particular, the model includes a realistic soil module which simulates both diffusion and convection of a tracer driven by evaporation from the soil, precipitation, and gravity.

The model is applied to a long-term simulation of the transport of pesticides (hexachlorocyclohexanes in particular). Emission fluxes from the soil are rigorously computed on the basis of the realistic data of the agricultural application. All four modelled systems, i.e. atmosphere, soil, hydrosphere and cryosphere, are driven by objectively analysed meteorological data supplemented, when necessary, by climatological information. Therefore, the verification against the observed data is possible. The comparison of the model results and the observations taken at remote stations in the Arctic indicates that the presented global modelling system is able to capture both trends and short-term components in the observed time series of the concentrations, and therefore, provides a useful tool for the evaluation of the source–receptor relationships.     

浅谈遥感技术在大气监测中的应用

碳的氧化物、硫的氧化物、氮的氧化物和臭氧等是人类在生产活动和社会活动产生中的主要的环境污染物,它们威胁着人类的生存环境和地球上的生态平衡。因此,对它们进行实时监测和综合治理显得非常重要。文章介绍了遥感(RS)技术,重点介绍遥感技术在大气环境监测中的应用。     

Mediterranean rural ozone characteristics around the urban area of Athens

A systematic analysis of surface ozone observations in rural areas surrounding Athens is presented. The analysis is based on ozone data for the rural station Aliartos about 80 km NW of Athens center and for two stations on the northern periphery of the Athens basin: Demokritos, located 10 km NE of Athens center and Liossia, 12 km to the north. The data for these two stations are screened for cases of strong air flow from rural areas. Average hourly summer afternoon ozone mixing ratios are similar for all three stations about 60 ppb and thus exceed for the hours 12:00–20:00 LST the 55 ppb WHO guideline for human health for 8 h ozone exposure. The corresponding winter afternoon mixing ratios are at 35 ppb. However, due to the large diurnal variation, mean monthly ozone mixing ratios at Aliartos, for the months April–September vary from 32 to 40 ppb, which is comparable to the higher average ozone levels at rural stations in south-central Europe. In cases of southerly air flow in the summer in the Athens basin, afternoon ozone levels at Demokritos and Liossia are generally the highest of any in the monitoring network. Hourly average concentrations, however, are only 40% greater than rural values. A background ozone level of such magnitude will have a significant impact on estimates for the effectiveness of pollution control measures for Athens.     

Mercury levels in sediments of central Mediterranean Sea: a 150+ year record from box-cores recovered in the Strait of Sicily

To evaluate the degree of anthropogenic mercury pollution, Hg contents have been measured for box-core sediments sampled along three nearshore–offshore transects in the Strait of Sicily and well constrained for their mineralogy, bulk geochemistry and TOC%. Hg values are generally low (from 15 to 70 μg kg⁻¹); however, depth profiles clearly display upcore rising concentrations (up to 202 μg kg⁻¹ near the SE Sicily coast) that are attributed to anthropogenic load. Based on ²¹⁰Pb chronology, these trends are more dramatic across the last 20–30 years. Geogenic influence is thought to explain some anomalies related to volcanic emission and geothermal activity. Combined effects due to eastward flowing of the Modified Atlantic Water (MAW) and sea bottom morphology drove major anthropogenic accumulation.     

京津冀地区大气NO2污染特征研究

京津冀都市圈作为全国主要的重化工业基地,区域性大气污染问题成为关注的焦点。NO2作为二次颗粒物及光化学污染物的重要前体物,了解其在时空尺度的污染特征对于保护公众康健及大气污染综合治理具有重要意义。本研究主要基于OMI遥感反演数据并结合部分地面监测数据,研究了2005—2013年京津冀NO2区域污染特征。结果表明：京津冀NO2柱浓度总体呈现逐年升高的趋势,年平均增长速率可达5.69%。在空间格局上呈东南平原区高、西北山区低的特征,平原的年均柱浓度是山区的3倍多;平原区存在两大NO2高值区域,分别为北京-天津-唐山区域和石家庄-邢台-邯郸区域;9年内, NO2高值范围不断扩大,且呈现明显的连片趋势。各城市大气 NO2在9年内的增长趋势也表现出明显的空间差异性。其中石家庄、唐山、邢台等 NO2重度污染区域的增长速率最大,衡水、沧州、秦皇岛、廊坊等中度污染区域的增长速率次之,承德、张家口等轻度污染区域的增长速率最小。京津冀NO2柱浓度具有显著的季节变化特征,总体表现为秋冬高、春夏低,但山区与平原区差异较大。人口密度、能源消耗、机动车排放等人为因素与京津冀 NO2污染密切相关,不同城市的首要影响因素却不同。北京 NO2柱浓度变化主要受机动车排放影响,天津、唐山、石家庄、邯郸、邢台地区主要受工业燃煤的影响,其次为机动车排放。人为因素对平原区NO2柱浓度的影响作用始终占据主导地位,对山区的主导作用从2006年开始突显。此外,京津冀平原区NO2重污染中心的形成还受到特殊地形和不利的气象条件影响。2008奥运年,京津冀空气质量得到迅速且有效的改善,说明北京及周边省市联合开展大气污染治理及监管工作的有效性及必要性。     

中国地区大气汞的干沉降速度

借助箱模式对汞的干沉降过程进行敏感性分析,并利用区域大气环境模式系统RegAEMS计算中国地区汞干沉降速度的时空分布特征。结果表明,森林下垫面下三类汞（气态零价汞、活性气态汞和颗粒态汞）的干沉降速度较大( 0.13、4.5和0.45 cm·s^-1),水体表面上的相对较小（0.0012,0.5和0.11 cm·s^-1）。敏感性分析发现,三类汞的干沉降速度随着近地层风速增加;降水或者地表湿度降低会导致零价汞和活性气态汞干沉降速度增加;雪盖厚度会减小气态零价汞的干沉降速度而增加活性气态汞的干沉降速度。三类汞的干沉降速度在区域上分布类似,东北以及南部地区最高,华东地区最小。季节变化上,气态零价汞、活性气态汞的干沉降速度在多数下垫面都夏季最大,冬季最小;颗粒态汞季节变化不明显。     

Rapid regional outburst elimination technology in soft coal seam with soft roof and soft floor

In order to solve the problems in outburst elimination of coal seams with outburst potential, methods of field testing, theoretical analysis and numerical simulation are employed in this study. It is found that the horizontal stress concentration surrounding coal unloading boreholes is the primary cause of the coal and gas blowouts in the process of the coal unloading and permeability improvement with high-pressure water jet. The results indicate that low borehole density and inefficient drainage are the main reasons for the occurrence of high outburst indices in the effeteness validation of regional measures to control outbursts. Based on numerical modeling results and onsite parameter testing, reasonable parameters such as borehole density are determined, and hydraulic fracturing is applied to improve coal seam permeability and relieve stress levels so as to eliminate regional outburst potential. The effect is significant in the field application, coal and gas blowout during the coal unloading period with high-pressure water jet is reduced dramatically, and the roadway development rate is increased by 48%. It is demonstrated that the gas drainage combined with the hydraulic fracturing, coal unloading with high-pressure water jet is a practical and effective technique for rapid elimination of coal and gas outburst potential in roadway development.