NUMERICAL MODELLING OF LITHOSPHERE EVOLUTION IN THE NORTH CHINA CRATON:THERMAL THINNING VERSUS TECTONIC EXTENSION THINNING

The boundary between lithosphere and asthenosphere essentially represents a thermal boundary (the solidus).Temperature variation across this boundary can lead to the change of lithosphere thickness.In the case of elevated temperatures in a lithospheric layer above 1 200℃,partial melting will begin and the result of that is a thinned lithosphere.The other mechanism that can also thin lithosphere is extension.     

北京奥运期间极端天气气候事件背景分析

利用北京市 1 951～ 2 0 0 1年 51年 7月下旬至 9月上旬的日最高气温、降水量、风、天气现象等观测资料 ,分别以旬为单位统计了高温、洪涝、大风、大雾、雷暴等对体育竞赛影响较大的极端天气气候事件发生的概率及分布特点 ,以期为 2 0 0 8年北京奥运会提供极端天气气候事件发生的气候背景资料。     

Rapid zonation of abrupt mass movement hazard: Part I. General principles

Hazards caused by mass movement cost many human lives and cause severe damage to property. Accurate zonation of such hazards provides an important tool for preventive measures. Previous approaches for mass movement hazard zonation are costly because they require large amounts of data, time and labor, and are only applicable to specific local areas. In this paper, a Rapid Zonation of Abrupt Mass-movement Hazard (RZAMH), applicable to large regions, is proposed. It involves the selection of appropriate zonation principles, routes, units, and indexes that can be used for the classification of reference groups, identification of matching groups of test sites, evaluation of blank test sites, and coalescence of sub-regions into specified zonation areas. The K-means clustering method is used in the classification processes. The applicability of the RZAMH approach to a large area implies that the number of reference sites required to build the reference groups is not of primary importance as long as the reference sites are representative. Therefore, for large areas, the RZAMH approach would be more economical than other conventional methods. The RZAMH approach is probably applicable to all abrupt mass movement hazards including rock falls, landslides, and debris flows.     

Lg magnitude determination for the eastern six Provinces of China (part 2)

Any pair ofm _{L gz} ,m _{L g} b,mmxz andmm x h in the eastern six provinces of China show good linear relation this makes it easy to convert from one scale to another.mm x h may replaceM _L (ECH) as the local earthquake magnitude scale for the eastern six provinces, yet retaining the level ofM _L (ECH). The scalemm x h is 0.36 magnitude units higher thanM _L (SC) for southern California. By comparingRm a x (Δ) withR ₃ (Δ) of Yunnan, it is found that the γ-value ofMAX phase of about 1 section in Yunnan region is half as large as that in the eastern six provinces of China. Observation indicates thatmm x h≈mb for magnitude 4–5. It follows therefore thatmb (ECH)≈mb (WUS). This is supported by the result that the attenuation coefficient, the γ-value in eastern China is the same as in western United States.     

基于GIS的城市地下管线空间分析模型的建立与实现

为提高城市地下管线的管理水平，利用地理信息系统技术(GIS)的空间分析功能，首先在分析地下管线的的实体-关系模型(E-R模型)的基础上，根据GIS空间分析的特点，提出了基于空间分析的城市地下管线的数据库结构；其次，根据城市管线规划、管理和施工的需要，建立了城市地下管线的纵断面、横断面、最佳路径、地下管线三维分析等几种空间分析模型，并对各种模型的表示内容和实现方法进行了阐述．从而实现了城市地下管线的可视化和动态化管理。该模型在青岛市综合地下管线管理系统应用后，提高了青岛市的城市规划和管线管理水平，促进了各个专业管线管理单位信息化和数字化进程。     

Spatial and temporal variations and controlling factors of potential evapotranspiration in China: 1956-2000

Based on the climatic data of 580 stations in China during 1956 and 2000, potential evapotranspiration are calculated using the Penman-Monteith Method recommended by FAO. The spatial and temporal distributions of the potential evapotranspiration over China and the temporal trends of the regional means for 10 major river basins and whole China are analyzed. Through a partial correlation analysis, the major climate factors which affect the temporal change of the potential evapotranspiration are analyzed. Major results are drawn as follows: 1) The seasonal and annual potential evapotranspiration for China as a whole and for most basins show decline tendencies during the past 45 years; for the Songhua River Basin there appears a slightly increasing trend. 2) Consequently, the annual potential evapotranspirations averaged over 1980-2000 are lower than those for the first water resources assessment (1956-1979) in most parts of China. Exceptions are found in some areas of Shandong Peninsula, western and middle basins of the rivers in Southwest China, Ningxia Hui Autonomous Region as well as the source regions of the Yangtze and Yellow rivers, which may have brought about disadvantages to the exploration and utilization of water resources. 3) Generally, sunshine duration, wind speed and relative humidity have greater impact on the potential evapotranspiration than temperature. Decline tendencies of sunshine duration and/or wind speed in the same period appear to be the major causes for the negative trend of the potential evapotranspiration in most areas.     

Spatial distribution characteristics of urban thermal conditions: application of GIS and remote sensing

Due to the limitation of site number, manpower and material resources, it is hard to gain a deep understanding of the plane distribution and internal structure of the thermal conditions by routine methods to study the thermal landscape characteristics of the ground surface. Using remote sensing method to study and analyze heat island effect has many advantages, such as high resolution, wide coverage and dense samples. In order to study, in advance and synchronously, the thermal distribution ch…     

植物始花期对气候变化响应的激素调控机理研究进展

植物物候对气候变化的响应非常敏感,是指示全球变化对生态系统影响的重要证据。其中植物花期变化影响植物繁殖与进化,具有重要意义。大量研究表明,随着全球气候变暖,北半球植物始花期普遍提前。而关于气候变暖对植物始花期影响的内在机理并没有明确解释。植物激素是植物体内对植物开花等生理活动有显著调控作用的有机物,可对环境刺激作出响应并直接参与调控植物始花期,导致始花期的提前或延后。对植物激素在植物中表达与变化的精确测定有助于了解植物始花期对气候变化响应的内在机理。论文综述了植物激素对植物开花时间的调控作用以及目前植物激素最先进的检测方法,探讨了植物激素及相关代谢产物在植物体内的含量变化对植物始花期的影响;提出通过植物激素研究植物始花期对气候变化响应的激素调控机理,为探索植物物候对气候变化响应提供新的研究思路与手段。     

Modelling the integrated effects of land use and climate change scenarios on forest ecosystem aboveground biomass,a case study in Taihe County of China

Global and regional environmental changes such as land use and climate change have significantly integrated and interactive effects on forest. These integrated effects will undoubtedly alter the distribution, function and succession processes of forest ecosystems. In order to adapt to these changes, it is necessary to understand their individual and integrated effects. In this study, we proposed a framework by using coupling models to gain a better understanding of the complex ecological processes. We combined an agent-based model for land use and land cover change (ABM/LUCC), an ecosystem process model (PnET-II), and a forest dynamic landscape model (LANDIS-II) to simulate the change of forest aboveground biomass (AGB) which was driven by land use and climate change factors for the period of 2010–2050 in Taihe County of southern China, where subtropical coniferous plantations dominate. We conducted a series of land use and climate change scenarios to compare the differences in forest AGB. The results show that: (1) land use, including town expansion, deforestation and forest conversion and climate change are likely to influence forest AGB in the near future in Taihe County. (2) Though climate change will make a good contribution to an increase in forest AGB, land use change can result in a rapid decrease in the forest AGB and play a vital role in the integrated simulation. The forest AGB under the integrated scenario decreased by 53.7% (RCP2.6 + land use), 57.2% (RCP4.5 + land use), and 56.9% (RCP8.5 + land use) by 2050, which is in comparison to the results under separate RCPs without land use disturbance. (3) The framework can offer a coupled method to better understand the complex and interactive ecological processes, which may provide some supports for adapting to land use and climate change, improving and optimizing plantation structure and function, and developing measures for sustainable forest management.     

基于BDI决策的MAS-CA模型黄海海滨城镇格局模拟研究——以大连金石滩为例

基于BDI决策MAS-CA模型,利用1998年、2003年、2008年和2013年土地利用数据,对大连金石滩2020年和2030年城镇区域面积进行模拟,Kappa系数达到0.635。研究结果表明：① BDI决策补充了MAS-CA模型决策的不足,使得模型整体框架进一步完善,模拟结果具体准确,精度达到89.1%。② 金石滩城镇用地呈现出依附海岸线和交通线的格局,向海岸线靠拢,城镇用地在中部区域比较集中且城镇用地有向周围区域扩张的趋势,葡萄沟村、河咀子村、庙上村、什字街村转变最大。③ 从金石滩城镇格局的模拟结果发现,海岸线因素引导着城镇格局的转变方向。滨海地区的生态环境容易被破坏,政府应该采取措施寻找土地利用与生态环境保护的完美平衡点。