移动式絮凝-气浮集成系统研制及其在城市污染河湖治理中的应用

针对北京城市河湖的污染状况，论述了传统絮凝一气浮工艺在污染治理中的应用研究及以该工艺为基础的集成系统的开发。结果表明，该系统对TP、COD去除率分别达81％和75％。该系统的研制成功为城市河湖的污染治理开辟了新途径。     

Long-range transport potential of semivolatile organic chemicals in coupled air-water systems

Ongoing deliberations on the regulation of semivolatile organic chemicals require the assessment of chemical transport in atmospheric and marine systems. The characteristic travel distance was proposed as a measure for the transport potential in air and water. However, the existing definition treats the transport processes separately. It is shown that combined transport in coupled air-ocean systems can accelerate the overall transport into remote regions. Concentration ratios in air and water change with distance from sources depending on the initial concentration ratio and on the difference between the transport velocities. A measure is suggested facilitating the chemical screening with respect to transport potentials in such air-ocean systems. A case study for alpha and gamma-hexachlorocyclohexane shows that the suggested measure qualitatively reveals the transport potentials of these chemicals and exemplifies possible concentration patterns.     

3S与在线监测技术在环境模型研究中的应用

结合环境信息系统的研究现状和研究实例，首先分析了3S和在线监测技术与环境模型研究结合的必要性，并分析指出了3S、在线监测技术在环境模型研究中潜在的应用范围，然后剖析了3S技术与环境模型研究结合的三阶水平，最后介绍了3S在环境规划模型研究中的理想结合框架。     

Refining Biodiversity Conservation Priorities

Abstract:  Although there is widespread agreement about conservation priorities at large scales (i.e., biodiversity hotspots), their boundaries remain too coarse for setting practical conservation goals. Refining hotspot conservation means identifying specific locations (individual habitat patches) of realistic size and scale for managers to protect and politicians to support. Because hotspots have lost most of their original habitat, species endemic to them rely on what remains. The issue now becomes identifying where this habitat is and these species are. We accomplished this by using straightforward remote sensing and GIS techniques, identifying specific locations in Brazil's Atlantic Forest hotspot important for bird conservation. Our method requires a regional map of current forest cover, so we explored six popular products for mapping and quantifying forest: MODIS continuous fields and a MODIS land cover (preclassified products), AVHRR, SPOT VGT, MODIS (satellite images), and a GeoCover Landsat thematic mapper mosaic (jpg). We compared subsets of these forest covers against a forest map based on a Landsat enhanced thematic mapper. The SPOT VGT forest cover predicted forest area and location well, so we combined it with elevation data to refine coarse distribution maps for forest endemic birds. Stacking these species distribution maps enabled identification of the subregion richest in threatened birds—the lowland forests of Rio de Janeiro State. We highlighted eight priority fragments, focusing on one with finer resolved imagery for detailed study. This method allows prioritization of areas for conservation from a region >1 million km² to forest fragments of tens of square kilometers. To set priorities for biodiversity conservation, coarse biological information is sufficient. Hence, our method is attractive for tropical and biologically rich locations, where species location information is sparse.     

Quantifying Land-Use Alterations and Associated Hydrologic Impacts at a Wetland Area by Using Remote Sensing and Modeling Techniques

Land use changes and associated hydrologic disturbances, mainly caused by human activities, is a common reason for wetlands degradation worldwide. The particular scientific effort utilized remotely sensed data, GIS techniques and hydrologic modeling to estimate land use alterations during a 40-years period as well as associated changes in hydrologic parameters such as overland and underground flow, infiltration, evapotranspiration and water storages on ground surface. The results indicated significant variations in the hydrologic regime including a 6% increase in the annual evapotranspiration and a 10% increase in the soil water deficit that impose substantial impacts on the regional wetlands.     

Supplementing Land-Use Statistics with Landscape Metrics: Some Methodological Considerations

Landscape monitoring usually relies on land-use statistics whichreflect the share of land-sue/land cover types. In order tounderstand the functioning of landscapes, landscape pattern mustbe considered as well. Indicators which address the spatialconfiguration of landscapes are therefore needed. Thesuitability of landscape metrics, which are computed from thetype, geometry and arrangement of patches, is examined. Two casestudies in a surface mining region show that landscape metricscapture landscape structure but are highly dependent on the datamodel and on the methods of data analysis. For landscape metricsto become part of policy-relevant sets of environmentalindicators, standardised procedures for their computation fromremote sensing images must be developed.     

Canada's National Forest Inventory (Responding to Current Information Needs)

Canada's current National Forest Inventory is a periodic compilation of existing inventory material from across the country. While the current approach has many advantages, it lacks information on the nature and rate of changes to the resource, and does not permit projections or forecasts. Beinga compilation of inventories of different dates, the current national forest inventory cannot reflect the current state ofthe forests and therefore cannot be used as a satisfactory baseline for monitoring change. The current format of Canada's National Forest Inventory has served its purpose by providingnational statistical compilations and reporting. However, itsuseful life is coming to a conclusion. To meet new demands, Canada is considering a new National Forest Inventory design consisting of a plot-based system of permanent observational units located on a national grid. The objective of the new inventory design is to assess and monitor the extent, state andsustainability of Canada's forests in a timely and accurate manner. Details of the new inventory design are described. A strategy to respond to Canada's national and international forest reporting commitments through a National Forest Information System is also discussed.     

A Comparison of Three Methods to Collect Submerged Aquatic Vegetation in a Shallow Lake

Two boat-based and one in-water sampling method have been used to collect submerged aquatic vegetation (SAV) as part of a long-term monitoring program in Lake Okeechobee, Florida, USA. The boat-based methods consisted of collecting SAV with a ponar dredge, used only to collect Chara, and an oyster tongs-like rake apparatus, used to collect all SAV. The in-water method involved use of a 0.5 m² PVC quadrat frame deployed by a diver. During summer 2002, SAV biomass samples were collected using all three methods at various sites in the lake to compare between-methods sampling precision. Sites used for these comparisons were selected based on plant type, plant density and sediment type. Statistical comparisons indicated that there were significant (p ≤ 0.05) biomass differences in 8 of 15 possible pairwise comparisons between sampling method biomass means. In four of the eight comparisons, significantly higher biomass mean values were obtained using the quadrat frame. In three of the remaining four comparisons, significantly higher biomass mean values were obtained with the rake apparatus. For the fourth comparison, a significantly higher biomass mean value was obtained with the ponar dredge. Three of the four relationships between SAV biomass collected by the rake and the quadrat and the rake and the quadrat/ponar dredge were statistically significant, linear and explained between 67 and 78% of the biomass variability. There were no significant differences between regression coefficients or elevations for these relationships, therefore these regressions estimated the same population regression. The population regression coefficient was 0.95, suggesting that the quadrat and ponar over-sampled relative to the rake, but the amount of this over-sampling was very small. Since there was no consistent pattern in the sampling method which yielded the significantly different biomass values and there were no significant differences in sampling precision across a range of plant species, plant densities and two sediment types, the boat-based rake method appears to be a suitable replacement for the previously used ponar dredge and quadrat methods, when in-lake measurements are not practical.     

Modeling Desertification Change in Minqin County,China

Monitoring environmental processes is becoming increasingly important wherever there is increasing population and economic development pressure placed on fragile environments. Remote sensing, digital image processing, and spatial analysis have proven to be useful technologies in both assessing and monitoring environmental change. In this study, they were used to assess desertification processes and change in Minqin County, China from 1988 to 1997. The results suggest that wind erosion was the dominant cause of desertification in more than half of the study area. Coupled with this were increases in salinization processes, affecting 33.62% of the land area in 1997. Overall, moderate desertification was found to be the dominant desertification grade (43.64% of total area), followed by extreme/severe desertification (26.15% of total area) in 1997. In addition, examination of landscape pattern changes indicated that desertification processes at the landscape level were becoming evident at increasing levels of fragmentation, complexity in shape, and isolation of patches. Major fluctuations in desertification type and grade were found at the fringes of oases, where an ongoing shift was taking place between cultivation, abandonment, and reclamation.     

1991～2016年黄河三角洲湿地变化的遥感监测

以1991、2000、2010和2016年的Landsat TM/OLI影像数据为基础,采用面向对象和目视解译的分类方法,提取了黄河三角洲湿地信息。同时,利用空间分析、动态度模型、非等间距序列灰色模型等分析方法,分析了湿地的时空变化特征,并结合相关文献资料讨论了湿地变化的驱动因素。结果表明,1991～2016年间,黄河三角洲湿地总面积逐渐减少,约91.39 km²。其中,以2000～2010年期间面积变化最为剧烈,自然湿地面积以30.21 km²/a的速度减少,而人工湿地以32.77 km²/a的速度增加。在各类型湿地中,草甸湿地面积减少最多,为312.83 km²;而人工湿地面积大幅增长,且以养殖池和盐田的增加最为迅速,增加了544.63 km²。从空间分布上来看,研究区人工湿地面积有逐渐向滨海区扩张的趋势。湿地养殖、农业开垦、工程修建等人类活动是导致黄河三角洲自然湿地减少的主要因素。