The influence of volcanism on paleoclimate in the northeast of China： Insights from Jinchuan peat, Jilin Province, China

Just like contemporary sediments, peat itself is a good repository of information about climate change, the effects of volcanic activity on climate change have been truly recorded in peat, since it is a major archive of volcanic eruption incidents. A section of sand was identified as tephra from the Jinchuan peat, Jilin Province, China, for the grains look like slag with surface bubbles and pits, characterized by high porosity, and loose structure with irregular edges and corners. According to the peat characteristics of uniform deposition, the tephra was dated at 2002–1976 a B.P. by way of linear interpolation, so the time of volcanic eruption was 15 B.C.–26 A.D. (the calibrated age). While the geochemical characteristics of tephra in this study are quite the same as those of tephra from the Jinlongdingzi volcano at Longgang and from alkaline basaltic magma, with the contents of SiO₂<55%, and the similar contents to Al₂O₃ and Fe, but the contents of Na₂O>K₂O. We speculated that the tephra in this study came from the Longgang volcano group. Compared with 11 recorded volcanic eruption events as shown on the carbon and oxygen isotope curves of the Jinchuan peat cellulose, it is obviously seen that adjacent or large-scale volcanic eruptions are precisely corresponding to the minimum temperature and humidity. It seems that these volcanic eruptions indeed affected the local climate, leading to the drop of regional temperature and humidity. As a result, there was prevailing a cold and dry climate there, and all these changes can be well recorded in peat. So the comparison of volcanic eruption events with information about climate change developed from peat, can provide strong evidence for the impact of volcanism on climate change.     

Application of 3-D Geoscience Modeling Technology for the Estimation of Solid Mineral Reserves

Abstract: Applying new approaches, methods, and technologies for the estimation of reserves can effectively improve the efficiency and accuracy of assessments of solid mineral resources. After analyzing the development of 3-D geoscience modeling technology (3-D GMT), this paper discusses the application of 3-D GMT for the estimation of solid mineral reserves, emphatically introducing its workflow and two key technologies, 3-D orebody surface modeling, and property modeling. Moreover, the paper analyzes the limitations of traditional methods, such as the section method and geological block method, and points out the advantages of 3-D GMT: building more accurate 3-D orebody models, expressing the internal inhomogeneous attributes of an orebody, reducing the potential for errors in the estimation of reserves, and implementing dynamic estimations of reserves.     

Enhancing the Two-Step Floating Catchment Area Model for Community Food Access Mapping: Case of the Supplemental Nutrition Assistance Program

In this article, a Gaussian-based two-step floating catchment area (2SFCA) model is applied to evaluate the geographical accessibility to Supplemental Nutrition Assistance Program (SNAP)-authorized retailers. First, the proposed method considers the interaction between the food supply (in terms of categorized benefit redemptions) and demand (in terms of benefit-receiving households). Second, the model is used to visualize food access patterns at the level of refined administrative units (i.e., census block groups). The developed food access metric was compared to the U.S. Department of Agriculture (USDA) Food Access Research Atlas, justifying the validity of this new method for small area estimation. The following are important observations: (1) the choice of catchment size had a considerable impact on the accessibility measure in urban areas (or when small statistical units are used); (2) the 2SFCA measurement had a higher level of correspondence with that of the USDA Atlas at a smaller catchment size for identifying low food access units; and (3) there was no significant inequality regarding SNAP accessibility with respect to different socioeconomic deprivation variables. This new method can better assist the SNAP administration with store authorization on a refined geographic scale. Key Words: food access, inequality, scale, Supplemental Nutrition Assistance Program (SNAP), two-step floating catchment area (2SFCA).     

The temporal hierarchy of shelters: a hierarchical location model for earthquake-shelter planning

The problem of emergency facility location is a critical component in evacuation planning. The emergence of geographic information systems (GIS) has provided a useful operational platform to assist this issue. A previously overlooked facet is the consideration of a hierarchical structure in the placement of emergency shelters. Due to the fact that survivors' needs change over time during post-disaster evacuations, shelters have now been categorized on a temporal scale based on their functions at different evacuation phases. This article proposes a three-level hierarchical location model for optimizing the placement of earthquake shelters by taking into account this temporal variance. The article not only scrutinizes the modeling procedure but also implements the model in a planning area with many real-world details. Based on the optimization results derived from a GIS context, we have found that the quality of the earthquake response procedure is not only dependent on the placement strategy of shelters, but more importantly on the financial constraints imposed on the planning and construction of these shelters. A discussion has been proposed to balance the trade-off between budget planning and evacuation efficiency. As the first attempt to model the hierarchical configuration of emergency shelters with specific focus on evacuees' escalating sheltering demands, this article will be of great significance in helping policy makers consider both the spatial and financial aspects of the strategic placement of emergency shelters.     

亚洲大洋洲区域综合地球观测系统计划进展

亚洲大洋洲区域综合地球观测系统是为实现国际地球观测组织总体战略目标而设立的区域地球观测合作计划,旨在面向亚大区域国家对地球观测技术的应用需求,保障亚大区域地球观测空间信息的精准获取与主动服务,增强地球观测技术支撑区域可持续发展的综合能力。该计划由地球观测组织亚大区域成员国共同提出,并对亚大地区的所有国家和参与组织开放。通过国际地球观测组织亚大区域政府间合作机制,在国家、区域和全球层面建立有效的合作框架,积极协调区域内的地球观测资源设施的互联互通、技术合作与共享服务,促进亚大区域国家在社会经济关键领域的应用,共同应对可持续发展、全球变化和重大灾害的挑战。     

Impact assessment of urbanization on flood risk in the Yangtze River Delta

The Yangtze River Delta region is the region with highest urbanization speed in China. In this study, 6 typical urbanization areas in Yangtze River Delta were selected as the objectives of study. Flood risk assessment index system was established based on the flood disaster formation mechanism, and analytic hierarchy process was utilized to define the weight of indices. The flood hazard, the exposure of disaster bearing body, the vulnerability of disaster bearing body and the comprehensive flood risk corresponding to three typical years in different urbanization stages, 1991, 2001 and 2006 were assessed. The results show that the flood hazard and the exposure of disaster bearing body in the 6 areas are all with an increasing trend in the process of urbanization, among which, the increasing trend of the exposure of disaster bearing body is especially obvious. Though the vulnerabilities of disaster bearing body in the 6 areas are all with decreasing trend owe to the enhancement of flood control and disaster mitigation capability, the comprehensive flood risks in the 6 areas increased as a whole, which would pose a serious threat to urban sustainable development. Finally, effective countermeasures for flood risk management of urbanization areas in Yangtze River Delta were put forward based on the assessment results.     

Study on projection of water resources of Dongting Lake catchment based on emission scenarios assumptions

ABSTRACT

With global climate change and impacts of human activity, the water cycle, which has a close relationship with local water resources, has changed rapidly. Based on different greenhouse gas emission scenarios, five relatively independent global climate models are selected from 47 CMIP5 models to simulate future climatic conditions. Data are downscaled to the local projection, with bias neutralized before applying them to the hydrological models, by which availability of future water resources are calculated for the Dongting Lake basin. The results show that the water resources of the Dongting Lake basin are likely to increase in the future, but be distributed more unevenly. All scenarios indicate that water availability will increase during the flood season and decrease during the dry season, with a prominent increase in annual discharge. The scenarios also predict that the greater the greenhouse gas emissions, the more uneven the water distribution becomes. Overall, the water resources of the Dongting Lake catchment show the same increasing and unevenly distributed trend in the future, which could be further accelerated by human activities.

Editor Z.W. Kundzewicz; Associate editor Q. Zhang     

Long-term variations of rainfall interception in different growth stages of Chinese fir plantations

Abstract

The dynamic properties of rainfall interception were investigated at three growth stages in Chinese fir plantations. The results showed that the annual interception ratio was significantly higher in mature stands than in young stands. For a storm event, interception rainfall amount increased with increasing rainfall, but interception ratio decreased. In contrast to dry season conditions, the interception amount was high in the wet seasons, while the interception ratio was low. The rates of change in interception ratio were extremely rapid in small rainfall events. There was little stemflow in Chinese fir forests due to the pyramid-shaped crowns and thick rough bark of the trees. The power model was suitable to describe the interception process for an individual rainfall event for stands of any age. Our results indicate that the interception process varied for stands of different ages in Chinese fir plantations due to contrasting canopy structures.     

2012年9月7日彝良5.7、5.6级地震预测及科学依据

通过分析彝良地震前地震预测意见和预测依据,认为:彝良地震前云南最主要的地震活动特征是境内6级以上地震平静时间接近或超过20世纪以来的极限时间,中等地震丛集过程中,缺少6级地震活动;宁蒗地震的窗口意义和前兆异常数量持续增加是判断地震短期危险性的主要依据;4级地震密集活动区为地点判断提供线索。彝良地震与缅甸地震同时孕育的复杂性,增加了地震预测的难度,也丰富了我们对地震孕育过程的认识。     

山东农村民居抗震设防调查与安全性评价

根据有关规定,对于有一定规模的建(构)筑物均应按安全性评价烈度鉴定结果进行抗震设防设计。但在广大的农村,大量民居是没有纳入管理的。由于中国农村人口所占比例很大,如有破坏性地震发生,这类建筑对人民生命财产造成的威胁是巨大的。山东省地震局、山东省建设厅及潍坊市市政府于2007年至2008年对诸城市农村民居现状进行了调查。本文对这批调查资料进行了整理。分析了诸城市农村民居的结构特点及地震安全的基本情况。通过与地震烈度图的对比,发现山东农村民居在抗震设防中存在的突出问题,并提出了应对方案。