平坦低地农业区人类活动影响下地形对森林分布的影响（英文）

Complex topography buffers forests against deforestation in mountainous regions.However,it is unknown if terrain also shapes forest distribution in lowlands where human impacts are likely to be less constrained by terrain.In such regions,if important at all,topographic effects will depend on cultural-historical factors and thus be human-driven(anthropogenic) rather than natural,except in regions where the general climate or extreme soils limit the occurrence of forests.We used spatial regression modeling to assess the extent to which topographic factors explain forest distribution(presence-absence at a 48×48 m resolution) in a lowland agricultural region(Denmark,43,075 km2) at regional and landscape scales(whole study area and 10×10 km grid cells,respectively),how landscape-scale forest-topography relationships vary geographically,and which potential drivers(topographic heterogeneity,forest cover,clay content,coastal/inland location) determine this geographic heterogeneity.Given a moist temperate climate and non-extreme soils all landscapes in Denmark would naturally be largely forest covered,and any topographic relationships will be totally or primarily human-driven.At regional scale,topographic predictors explained only 5% of the distribution of forest.In contrast,the explanatory power of topography varied from 0%–61% at landscape scale,with clear geographic patterning.Explanatory power of topography at landscape scale was moderately dependent on the potential drivers,with topographic control being strongest in areas with high topographic heterogeneity and little forest cover.However,these conditioning effects were themselves geographically variable.Our findings show that topography by shaping human land-use can affect forest distribution even in flat,lowland regions,but especially via localized,geographically variable effects.     

生态斑块粒度效应研究——以长三角地区无锡市为例

从人为干扰明显、生态性脆弱、幅度范围在1 000km2的角度出发,该文选取了长三角地区无锡市为研究对象。通过采用多因子加权叠加模型方法获取了研究区的生态斑块,借助景观指数等探讨了生态斑块粒度效应及其临界变化情况。结果表明:1)以生态斑块为研究斑块类型时,类型水平景观指数、景观水平指数和面积变化指数均具有明显粒度效应,并存在临界粒度和尺度域现象。2)三类指数的临界粒度一致为粒度2,即实际为60m;尺度域分别为(2,30)、(2,10)和(2,10),综合尺度域为(2,10),即实际为60～300m,是符合研究区特性的尺度域。在该尺度域范围内,指数粒度变化响应曲线变化平稳,蕴含的生态过程较为相似,进行尺度推绎具有可行性。     

不同人为干扰程度对森林土壤水分物理性质的影响

本研究探讨了不同人为干扰程度下米槠林地的土壤水分物理性质。结果表明,随着人为干扰强度的增加,容重呈现明显的增加的趋势,人促更新林容重大于其他林分,天然林容重最小。天然林转变为天然更新林,非毛管孔隙度增加2.39%,而转变为人促更新林非毛管孔隙度减少了1.01%;毛管孔隙度和总孔隙度的变化趋势一致,天然林转为天然更新林、人促更新林均减少。天然林的毛管持水量、最小持水量、最大持水量均最大。这表明随着人为干扰程度增加,对土壤水分物理性质影响越大。     

数据共享与学科交叉研究——浅析社科领域的GIS系统应用

随着GIS产业的建立和数字化信息产品在全世界的普及,GIS已然发展成为一个以领域应用为主的信息产业。纵观现今GIS技术的科研应用领域,大多数领域的应用都集中在具有很强空间属性的自然科学范畴中,而在同样需要时空属性支持的哲学人文社会科学领域却为数不多。因此,为了增强对哲学人文社会科学领域研究中与时空属性相关的支持,研究GIS技术在哲学人文社会科学领域中的应用,中国社会科学综合地理信息服务平台应运而生。本文从社科领域GIS技术应用的现状研究着手,详细分析了中国社会科学院所特有的丰富资源基础,阐述了中国社会科学综合地理信息服务平台系统的建设目标和主要功能提供,并进行了系统的应用前景展望。     

考虑人体舒适度的大型火车站房楼盖振动控制研究

近年来,各地纷纷兴建大型火车站房,这类建筑中的楼盖大多为大跨、轻质和低阻尼结构,本文基于人体舒适度考虑,对这些大跨楼盖进行振动舒适度的分析。首先,建立某大型火车站房的整体有限元模型,研究这类建筑中大跨楼盖的振动特性;随后,对楼盖在各种不利工况人群荷载作用下的振动舒适度进行分析;最后,在已有研究的基础上,提出了大跨楼盖多重调谐质量阻尼器（Multiple Tuned Mass Dampers,简称MTMD）减振设计方法。结果表明,利用该方法设计MTMD减振系统,可以有效地控制大跨楼盖的竖向振动,各工况下的平均减振率可达34%,从而使结构在使用时满足人体舒适度的要求。     

近30年江苏人体舒适度指数变化特征分析

利用江苏地区37个观测站1980－2009年逐日气象资料,通过线性趋势以及通径分析法,对人体舒适度指数（CIHB）的时空演变特征进行了分析。结果表明：（1）近30年来,江苏年均CIHB呈现显著的上升趋势,线性趋势为0.11/年,淮北、江淮之间、苏南的CIHB年际变化特征与全省平均的演变特征基本保持一致;（2）除夏季外,其余三个季节的CIHB均有较明显的上升趋势,其中春季的上升趋势最为明显,秋季次之,冬季的年际变化幅度最大,CIHB春、夏（秋、冬）两季的南北差异较小（较大）;（3）CIHB与温度（相对湿度和风速）存在显著的正（负）相关,其中温度对CIHB的正影响最大,相对湿度和风速对CIHB的最终影响是通过温度起负作用;（4）虽然近30年江苏整个夏季的CIHB不存在明显的变化趋势,但自20世纪90年代初期以来,7、9月份还是存在着弱上升趋势。研究表明,在全球气候变暖的大背景下,对江苏地区的CIHB气候变化特征的研究可为人们应对气象要素变化采取有效防范措施以及旅游、能源业的气象服务提供一定的科学依据。     

基于手机信令数据的城市小活动空间人群空间分布特征

小活动空间人群是指日常活动范围较小的居民群体,他们对城市公共资源的需求主要集中在家庭位置附近的区域,分析其活动的时空规律特征,有助于更好地实现城市公共资源的均等化和精准化配置。然而目前研究中对此类人群关注较少,为此,本文提出一种基于手机信令数据的小活动空间人群识别及其空间分布的研究方法。首先识别用户家庭位置和停留点位置,构建基家最大距离指标,度量用户以家庭位置为中心的活动空间范围,并据此筛选小活动空间人群;其次根据用户与家庭位置间的距离信息构建“时间-距离”框架下的用户轨迹,在此基础上构建基于面积的轨迹相似性方法;然后利用逐级合并的层次聚类算法,根据用户轨迹的相似性对其进行聚类,挖掘小活动空间人群中典型活动模式;最后根据用户的家庭位置,进一步分析不同活动模式人群的时空分布特征。本文以上海市手机信令数据为例对该方法进行了测试,结果表明：① “时间-距离”框架下构建的基于面积的轨迹相似性方法,可反映用户基于家庭位置进行活动的时空特征,而逐级合并的层次聚类算法对典型活动模式挖掘的效率有明显提高,有助于研究城市居民的移动模式;② 上海市小活动空间人群分布呈现出圈层结构,主要分布在中心城区,郊区的工厂和大学城以及各区的商业中心附近,在郊区过渡区相对较少。本文提出的方法能够用于分析城市小活动空间人群的时空分布特征,可以为目前各大城市提出建设社区生活圈的决策提供方法支撑。     

废弃生产场地有机氯农药的残留与迁移特征

我国历史上曾生产和使用了大量的有机氯农药,现存的有机氯农药生产企业场地是污染高风险区.先前的报道多集中在场地内污染特征研究,较少关注场地周边有机氯农药污染及其环境风险性.为了解有机氯农药场地土壤污染水平及其对周边环境的影响,本文以重庆某废弃有机氯农药场地及其周边为研究区域,分析土壤中六六六(HCHs)、滴滴涕(DDTs)及其降解产物的含量水平,阐明场地内污染特征以及周边土壤的残留规律,评估场地内及周边土壤中有机氯农药污染的人体健康风险.结果表明,场地土壤中∑HCHs的含量水平为3.89 ～ 13385.78 ng/g,低于国内已报道的其他污染场地.∑DDTs的含量水平为22.74 ～ 11186.10 ng/g,与已报道的我国张家口、扬州等地生产场地污染水平相当,但低于邢台、太原和青岛等地农药厂生产场地污染水平.该生产场地土壤中有机氯农药污染的人体致癌风险值均高于可接受的范围,属于重污染区.场地周边400 m范围的土壤中HCHs和DDTs的含量水平虽整体上低于场地内,但污染水平也较高,HCHs污染和DDTs污染的总致癌风险均超过了儿童可接受的限值.随着与生产场地距离的增加,场地周边土壤HCHs和DDTs的含量水平呈幂函数下降的趋势,这同时又表明生产场地有机氯农药仅对场地周边一定范围内的环境产生较大污染.因此,对于生产场地污染不能仅仅关注场地内,还应充分考虑场地周边一定范围内的污染与环境风险性.     

Impacts of geoscience research on the physical environment of the Vestfold Hills,Antarctica

Antarctic polar deserts can be of considerable scientific interest, but can also exhibit great environmental sensitivity. A variety of factors, including Australia's legal obligations under the Madrid Protocol, public expectations, certain research opportunities and ethical considerations, demand a very high standard of environmental protection. A survey outside the Davis Station limits in the Vestfold Hills, East Antarctica, identified 66 sites at which past human activities had left long term impacts on the physical environment. Nearly half of all observed impacts were the result of geoscientific research that had left old pit and trench sites, vehicular tracks, partly excavated palaeontological material, rock sampling and drilling sites, localised slope instability caused by disturbance, and discarded equipment and markers. Comparisons between rehabilitated sites and others where little, if any, rehabilitation appears to have been attempted suggest natural processes alone are generally insufficient to heal the damage, but that effective rehabilitation is often possible if undertaken immediately after the initial disturbance.     

Assessing human impact on alluvial fan development: a multidisciplinary case-study from Lower Khuzestan (SW Iran)

This paper presents a multidisciplinary approach for studying the evolution of an alluvial fan system in Lower Khuzestan (SW Iran). The study draws on previously collected data from geological and archaeological field campaigns and new data derived from the interpretation of satellite imagery and historical textual sources. Three alluvial fans were identified, successively deposited by the Jarrahi river in progressively downstream/westward direction. Judging from archaeological and historical evidence, the successive phases appear to coincide with a relocation of settlement and irrigation activities. The distributary system of the present-day fan developed over a period of less than four centuries. It is suggested that management of levee breaks by man played a key role in such rapid fan development and in maintaining extremely low gradients. Judging from the extensive patterns of ancient irrigation canals, human activity also played an important role in the formation of the earlier fans.