大别山东麓河流阶地初步研究

基于遥感解译、野外调查、光释光(OSL)测年和无人机地形测绘,对大别山东麓桐城-太湖段河流阶地发育特征与变形情况进行初步研究。结果表明：1）大别山东麓河流阶地发育较差,各中小型河流普遍发育一级阶地,少数大型河流发育2级阶地;2）大别山东麓河流T1阶地形成时代为晚更新世晚期至全新世早期(约25 ka BP~12 ka BP),T2阶地形成时代为晚更新世中期(约55 ka BP);3）郯庐断裂带大别山东麓段自河流T2阶地形成以来未发生明显活动,该段最新活动时代为中更新世。     

胶东辽上特大型金矿床地质特征

辽上金矿床位于胶东新发现的胶莱盆地东北缘成矿区之内,为胶东东部首例特大型金矿。矿区金成矿以充填作用为特征,载金矿物主要为自形—半自形结构黄铁矿和白云石,以网脉状、细脉状、微细脉状黄铁矿白云石细脉形式出现于岩石碎裂隙中,或以黄铁矿白云石大脉状充填于断裂构造中。矿石包括含金黄铁矿白云石脉型和含黄铁矿白云石脉蚀变岩型2大类。通过对比认为,该矿床为一新类型,即黄铁矿白云石脉型金矿床。这一新类型特大型金矿的发现,预示着胶莱盆地边缘地区具有较好的找矿前景,尤其在金牛山地区应有可能在短期内取得更大的找矿突破。     

贡嘎山海螺沟典型植被带总磷分布特征

由于独特的生物地球化学循环方式,磷已成为影响山地生态系统发育和安全的重要元素。为了了解贡嘎山磷的生物地球化学循环,对贡嘎山海螺沟坡地典型植被带土壤、植物根际土壤、植物不同部位总磷在生长季(9月)和非生长季或生长季初期(5月)的分布特征进行调查。结果表明:土壤总磷的分布在垂直梯度上的差异以及同一土壤剖面不同土壤层总磷的差异均较明显,同时还呈现明显的季节性差异,这些差异的形成与土壤发育程度、温度变化及植物生长有关;不同根际土壤在非生长季或生长季初期总磷的差异非常大,而在生长季较为接近,进一步说明植物对山地磷的生物地球化学循环存在较大影响;杜鹃、冬瓜杨、柳的叶较幼枝更富集磷,而峨眉冷杉、麦吊杉、竹的幼枝较叶所含磷略高。     

Succession Features and Dynamic Simulation of Subalpine Forest in the Gongga Mountain, China

The Gongga Mountain of eastern Tibet Plateau is a representative of the alpine regions with high peaks and deep valleys. Climate change over the last thousand years has controlled the dynamics of glacier and debris flow occurrence, which resulted in substantial changes in the mountainous environment. The authors surveyed the community structure of primary forests in Gongga Mountain and forest successign processes in woodland plots. The changing features in the subalpine environment are discussed in this paper. Tree species and sizes between the glacier shrinking areas and debris flow fans in Hailuogou Valley are compared. The pioneer species that settle in debris flow fans and the glacier shrinking areas are Salix spp. and Populus purdomii. Abies fabri and Picea brachytyla are the climax tree species. The succession process of primary vegetation in Hailuogou (2700 ～ 3200 m) can be divided into four stages:     

Rebirth after death: forest succession dynamics in response to climate change on Gongga Mountain,Southwest China

Global climate change is having long-term impacts on the geographic distribution of forest species. However, the response of vertical belts of mountain forests to climate change is still little known. The vertical distribution of forest vegetation(vertical vegetation belt) on Gongga Mountain in Southwest China has been monitored for 30 years. The forest alternation of the vertical vegetation belt under different climate conditions was simulated by using a mathematical model GFSM(the Gongga Forest Succession Model). Three possible Intergovernmental Panel on Climate Change(IPCC) climate scenarios(increase of air temperature and precipitation by 1.8℃/5%, 2.8℃/10% and 3.4℃/15% for B_1, A_1B and A_2 scenarios, respectively) were chosen to reflect lower, medium and higher changes of global climate. The vertical belts of mountainous vegetation will shift upward by approximately 300 m, 500 m and 600 m in the B_1, A_1B and A_2 scenarios, respectively, according to the simulated results. Thus, the alpine tree-line will move to a higher altitude. The simulation also demonstrated that, in a changing climate, the shift in the vegetation community will be a slow and extended process characterized by two main phases. During the initial phase, trees of the forest community degrade or die, owing to an inability to adapt to a warmer climate. This results in modest environment for the introduction of opportunistic species, consequently, the vegetation with new dominant tree species becomes predominant in the space vacated by the dead trees at the expense of previously dominated original trees as the succession succeed and climate change advance. Hence, the global climate change would dramatically change forest communities and tree species in mountainous regions because that the new forest community can grow only through the death of the original tree. Results indicated that climate change will cause the change of distribution and composition of forest communities on Gongga Mountain, and this change may enhance as the intensity of climate change increases. As a result, the alternation of death and rebirth would finally result in intensive landscape changes, and may strongly affect the eco-environment of mountainous regions.     

太行山东麓汤西断裂南段活动特征分析

采用槽探、年代样品测试、阶地调查和形变测量监测等方法，对太行山东麓汤西断裂南段进行研究，分析其活动特征。结果表明，汤西断裂发育于中更新世，历经多次活动，断裂并未上延到上更新统地层中，其南段的活动强度较高，最新活动年代为中更新世；汤西断裂西代村场地的垂直形变监测（1999~2014年）结果存在异常，综合监测点数据和区域新构造特征分析发现，该异常可能是研究区区域形变场的反映，并非由汤西断裂活动引起。     

中国历史山洪灾害分布特征研究

中国山洪灾害发生频繁,区域分布差异性明显且难以预报,关于山洪灾害分布特征的研究对于山洪灾害预警、山洪灾害防治区规划等具有重要意义。本文以历史山洪灾害点为基础数据,以6个一级地貌大区（东部平原低山丘陵大区（Ⅰ）、东南低山丘陵平原大区（Ⅱ）、华北-内蒙东中山高原大区（Ⅲ）、西北高中山盆地高原大区（Ⅳ）、西南中低山高原盆地大区（Ⅴ）、青藏高原高山极高山盆地谷地大区（Ⅵ））为基本分析单元,统计对比不同地貌区域内山洪灾害数目、密度,并进一步分析山洪灾害随高程、高程标准差以及50年一遇6 h雨量（H6-50）的分布情况,从而获得中国历史山洪灾害的主要分布特征。结果表明：山洪灾害集中分布于东南低山丘陵平原大区及西南中低山高原盆地大区,占全国山洪灾害的60%左右。6 h雨量（H6-50）处于240~280 mm区域山洪灾害密度最大。高程标准差小于30 m区域山洪灾害密度较大。东南低山丘陵平原大区高程处于10~50 m间,高程标准差小于30 m,雨量（H6-50）在150~270 mm间地区山洪灾害密度较大;西南中低山高原盆地大区山洪灾害集中分布于高程600 m以下,高程标准差小于50 m,雨量（H6-50）大于120 mm地区。以地貌区划结果为基本分析单元相对于行政界线而言更有助于分析山洪灾害分布特征。     

Temperature and precipitation variations at two meteorological stations on eastern slope of Gongga Mountain, SW China in the past two decades

Gongga Mountain, locates on the eastern edge of Tibetan Plateau of China, is the highest mountain in China except summits in Tibet. Only limited meteorological data on Gongga Mountain have been published so far. Here we present the meteorological records from two stations, Moxi Station (at 1,621.7 m above sea level (a.s.l.), 1992–2010) and Hailuogou Station (at 2,947.8 m a.s.l., 1988–2010), on the eastern slope of Gongga Mountain. In the past two decades, the annual precipitation decreased while the annual mean temperature increased at Hailuogou Station. Both precipitation and temperature increased at Moxi Station. The precipitation variation on the eastern slope of Gongga Mountain is influenced by both East Asian Monsoon and Indian Monsoon, so that the precipitation concentrated between May and October. The temperature variation on the eastern slope of Gongga Mountain in the past two decades showed similar trends as that of the northern hemispheric and global. In the past two decades, the temperature increased 0.35°C and 0.3°C/decade at Hailuogou Station and Moxi Station respectively, which was higher than the increase extents of northern hemispheric and global temperature. The most intense warming occurred at the first decade of 21st century. The winter temperature increased more at Hailuogou Station than at Moxi Station. A remarkable increase of temperature in March was observed with only a little precipitation at both high and low altitude stations.     

山东省山丘区地质灾害特征

山东省地形地貌条件复杂,崩塌、滑坡、泥石流等突发性地质灾害时有发生,对人民生命财产安全造成了极大威胁。为进一步研究地质灾害发生规律,为地质灾害防治提供技术支撑,根据山东省开展完成的1∶5万地质灾害调查工作成果,分析总结了全省山丘区地质灾害发育类型、分布规律以及发展趋势。