Systematic GIS-based landslide inventory as the first step for effective landslide-hazard management

The purpose of the so-called IFFI project (Inventario dei Fenomeni Franosi in Italia—Inventory of Landslides in Italy) and of many other related activities carried out by the Centro Regionale per le Ricerche Territoriali e Geologiche of ARPA Piemonte (Agenzia Regionale per la Protezione Ambientale—Regional Agency for Environmental Protection), is to map all the existing landslides in Piemonte (including both results of monitoring data and available historical data). ARPA carried out new systematic surveys using airphoto interpretation and created a specific alphanumeric geological information systems (GIS)-based database to store and process all the collected data. In order to obtain proper landslide-hazard zoning, it is necessary to provide a landslide inventory and to define the relationship between landslides and geological setting. A landslide inventory represents a fundamental base of knowledge, is a very basic tool for land planning, and strongly helps the local authorities in their decision making.     

聊古一井气体总量异常变化分析

2003年5月初至2003年10月下旬，聊古一井气体总量现明显的低值异常过程，在对上述异常变化进行现场分析落实的基础上，结合对聊古一井水化学测项投测以来地震异常特征和聊古一井水化学测项前兆意义的分析结果，认为聊古一井气体总量的异常变化属场兆异常，可作为该井周围不同地震构造带上发生5级以上地震的一种判据。聊古一井气体总量异常过程较好地对应了2003年11月25日山西洪洞发生的5．0级地震。     

世界滑坡目录工作组建议的滑坡术语

本文介绍了联合国教科文组织世界滑坡目录工作组建议的描述滑坡特征，量度、活动状态，活动型式和类型等的基本滑坡术语。     

Quantifying Uncertainty in Mineral Resources by Use of Classification Schemes and Conditional Simulations

Mineral inventory determination consists of estimating the amount of mineral resources on a block-by-block basis and classifying individual blocks into categories with increasing level of geologic confidence. Such classification is a crucial issue for mining companies, investors, financial institutions, and authorities, but it remains subject to some confusion because of the wide variations in methodologies and the lack of standardized procedures. The first part of this paper considers some of the criteria used to classify resources in practice and their impact through a sensitivity study using data from a Chilean porphyry copper deposit. Five classification criteria are compared and evaluated, namely: Search neighborhoods, absolute and relative kriging variances, absolute and relative conditional simulation variances. It is shown that some classification criteria either favor or penalize the high-grade areas if the grade distribution presents a proportional effect. In the second part of the paper, conditional simulations are used to quantify the uncertainty on the overall mineral resources. This approach is promising for risk analysis and decision-making. Unlike linear kriging, simulations allow inclusion of a cutoff grade in the calculation of the resources and also provide measures of their joint uncertainty over production volumes.     

Biomass mapping using forest type and structure derived from Landsat TM imagery

A method for mapping forest biomass was developed and tested on a study area in western Newfoundland, Canada. The method, BIOmass from Cluster Labeling Using Structure and Type (BioCLUST), involves: (i) hyperclustering a Landsat TM image, (ii) automatically labeling the clusters with information about forest type and structure, and (iii) applying stand-level equations that estimate biomass as a function of height and crown closure within forest species-type classes. BioCLUST was validated with biomass values measured at geo-referenced field plots and mapped across the study area using an existing forest management photo-inventory. Root mean square error (RMSE) values ranged from 43 to 79 tonnes/ha, and were lowest for intermediate height classes when validated with field plots. Overall bias was negative at 10 tonnes/ha compared with a negative bias of 3 tonnes/ha estimated for the photo-inventory. Validation of the biomass map gave RMSE values of 37–47 tonnes/ha and overall landscape biomass estimates within 0.4% of biomass mapped by the photo-inventory. BioCLUST offers an alternative to other biomass mapping methods when scene-specific plot data are limited and a photo-inventory is available for a representative portion of a Landsat scene.     

The potential of using LiDAR and color-infrared aerial imagery for palustrine wetland typology and change

Wetlands are dynamic landscapes and their spatial extent and types can change over time. Mapping wetland locations, types, and monitoring wetland typological changes have important ecological significance. The National Wetlands Inventory data suffer from two problems: the omission error that some wetlands are not mapped, and the out-of-date wetland types in many counties of the United States. To address these two problems, we proposed an automatic wetland classification model for newly mapped (or existing) wetland polygons lacking typological information. The research goals in this study were (1) to develop a nonparametric and automatic rule-based model to assign wetland types to palustrine wetlands using high-resolution remotely sensed data and (2) to quantify wetland typological changes based on the wetland types obtained from the previous step. The model is a direct application of the Cowardin et al. (1979) wetland classification system without modification. The input information for the proposed model includes Light Detection and Ranging (LiDAR)-derived vegetation height and color infrared aerial imagery-derived vegetation spectral information. We tested the model for the palustrine wetlands in Horry County, SC, and analyzed 29,090 palustrine wetland polygons (101,427 ha). The model achieved an overall agreement of 87% for wetland-type classification and showed the dynamics of wetland typological changes. This nonparametric model can be easily applied to other areas where wetland inventory needs updating.     

石油与天然气生产过程甲烷逃逸排放检测与核算研究现状及建议

甲烷作为油气生产中的主要气态污染物和增温潜势较强的一类温室气体,其逃逸排放检测与核算是中国油气行业温室气体控制与减排过程中的首要问题。通过比较国内外油气行业逃逸甲烷排放核算方法,以及总结当前国内外油气田现场开展的甲烷排放检测研究,对油气行业企业级温室气体清单编制提出了建议。在甲烷逃逸排放核算方面,由于生产过程、工艺等出现的变化,建议加快建立符合我国油气生产实际情况的排放因子,纳入放空气燃烧的周期变化、绿色完井措施使用、陆上/海上油气生产等内容,鼓励油气生产企业通过设备组件统计、现场实测等方式进行排放因子更新。针对逃逸甲烷现场检测数据不足,影响核算结果对比的现状,在开展油气生产过程现场检测时,建议自下而上与自上而下检测方法相结合,保证检测结果的可验证性、可重复性,并谨慎看待针对部分油气生产区块的检测结果进行大尺度区域甲烷逃逸排放量的推算结果。     

Estimating building exposure and impact to volcanic hazards in Icod de los Vinos,Tenerife (Canary Islands)

Principal and subsidiary building structure characteristics and their distribution have been inventoried in Icod, Tenerife (Canary Islands) and used to evaluate the vulnerability of individual buildings to three volcanic hazards: tephra fallout, volcanogenic earthquakes and pyroclastic flows. The procedures described in this paper represent a methodological framework for a comprehensive survey of all the buildings at risk in the area around the Teide volcano in Tenerife. Such a methodology would need to be implemented for the completion of a comprehensive risk assessment for the populations under threat of explosive eruptions in this area. The information presented in the paper is a sample of the necessary data required for the impact estimation and risk assessment exercises that would need to be carried out by emergency managers, local authorities and those responsible for recovery and repair in the event of a volcanic eruption. The data shows there are micro variations in building stock characteristics that would influence the likely impact of an eruption in the area. As an example of the use of this methodology for vulnerability assessment, we have applied a deterministic simulation model of a volcanic eruption from Teide volcano and its associated ash fallout which, when combined with the vulnerability data collected, allows us to obtain the vulnerability map of the studied area. This map is obtained by performing spatial analysis with a Geographical Information System (GIS). This vulnerability analysis is included in the framework of an automatic information system specifically developed for hazard assessment and risk management on Tenerife, but which can be also applied to other volcanic areas. The work presented is part of the EU-funded EXPLORIS project (Explosive Eruption Risk and Decision Support for EU Populations Threatened by Volcanoes, EVR1-2001-00047).     

近几十年来黑河野牛沟流域的冰川变化

利用1956年航测、1970/1973年1:50000地形图以及野牛沟流域2003年ASTER影像获取的3期冰川资料,对黑河源头西支野牛沟流域的冰川时空变化进行了分析.通过分析流域气温变化和冰川变化的关系,探讨了流域冰川变化对河川径流的影响.结果表明:野牛沟流域1956—1970/1973年冰川总面积减少9.29%,年平均消退0.54%;1970/1973—2003年冰川总面积减少了18.23%,年平均消退0.60%.流域内冰川条数由1956年的165条减少为2003年的144条,1956—1970/1973年间流域冰川储量减少了2.29×10⁸m³,年均损失约0.13×10⁸m³;从1970/1973年到2003年,冰川储量减少了4.19×10⁸m³,年均损失约0.14×10⁸m³.从1956年到2003年,冰川变化率随着冰川面积的增加而降低,冰川萎缩速度有加快的迹象,而流域年平均温度也有加快升高的趋势.冰川的消退对于流域径流量的影响不大.     

The role of wildfire and gully erosion in particulate Pb export from contaminated peatland catchments in the southern Pennines, U.K.

The near-surface layer of peatlands of the Peak District, southern Pennines, UK, is severely contaminated with atmospherically deposited Pb. Contemporary catchment soil Pb inventories at Upper North Grain and Torside Clough reveal that  23% and  54%, respectively, of the potential store of Pb in each catchment has been lost through erosion of the contaminated near-surface peat layer. Soil Pb inventories and the Pb content of suspended sediments reveal that, in both catchments, the main mechanism for contemporary particulate Pb export is gully erosion. Historical sheet erosion on bare peat flats at Torside Clough has released significant quantities of Pb into the fluvial system, triggered by the exposure of the near-surface peat during an accidental wildfire in 1970. Up to 32% of the total Pb export from the catchment may have been released during a discrete erosion event soon after the wildfire. Accidental wildfires and the subsequent release of highly contaminated peat into the southern Pennine fluvial system may increase under predicted climate change scenarios.