“高分二号”卫星在黄土地质灾害解译中的应用研究

黄土高原地区地质灾害多发频发,危害严重,应用亚米级的高分二号(GF-2)卫星影像数据,提取地质灾害信息,并对室内解译结果进行了野外查证。本文提出了以GF-2卫星数据为主要信息源,进行地质灾害解译的技术方案;并以宁夏南部黄土高原区为例,验证了该方法的适用性,为规模化地开展基于国产高分系列卫星的黄土高原地区地质灾害遥感解译提供了可行的技术方案;通过GF-2卫星影像与常用的国内外卫星数据用于地质灾害信息判释的对比研究,认为GF-2卫星影像对于地质灾害信息的识别能够满足地质灾害遥感解译的要求,GF-2卫星影像的应用具有较高的性价比和显著的经济社会效益。     

Use a Spatial Analysis Model to Assess Habitat Quality in Lashihai Watershed

Habitat quality assessments are of great significance for protecting biodiversity. This study analyzes the changing habitat quality of Lashihai watershed based on SPOT satellite images. We extracted the land use data for Lashihai watershed in Yunnan province for the years 2000 and 2015, and then used an InVEST model to evaluate habitat degradation, habitat quality and habitat scarcity in the study area from 2000 to 2015. Spatial statistical methods were used to determine changes to spatial dynamics. Results indicate that the number of areas with habitat degradation was generally small, and that both the number of areas with habitat degradation and the degree of degradation had fallen noticeably during the fifteen-year study period. In general, the quality of habitats was maintained or improved, while the quality of habitats decreased in only a few areas. The scarcity of habitats for cultivated land had increased, the tension between people and land use was relatively prominent. The reason habitat quality in Lashihai watershed has improved can be attributed to three factors: 1) The policy of returning farmland to forests since 2000 has been well implemented and has achieved remarkable results. Loss of forests from logging and deforestation has basically been eliminated, and great progress has been made restoring the ecological environment. 2) High background value of quality habitat suitability benefits from the research area’s high vegetation coverage. 3) The development of the local tourism economy has transformed the area’s ecological advantages into an economic bonus, greatly increasing the income level and living standards of residents. At the same time, the ecological resource bonus has increased the enthusiasm of residents for ecological protection and has helped to promote the protection of local eco-systems, both reducing ecological degradation and improving habitat quality. At the same time, increasing conflicts between land and people should be addressed. Support is needed to promote development of the ecological economy while continuously reducing ecological degradation and further increasing residents’ income. There must be less reliance on industry and less pressure on both land and people, all the while ensuring that the local economy and ecology can more forward together in a sustainable way.     

An Abrupt Rainfall Decrease over the Asian Inland Plateau Region around 1999 and the Possible Underlying Mechanism

A decadal change in summer rainfall in the Asian inland plateau(AIP) region is identified around 1999. This decadal change is characterized by an abrupt decrease in summer rainfall of about 15.7% of the climatological average amount,leading to prolonged drought in the Asian inland plateau region. Both the surface air temperature and potential evapotranspiration in the AIP show a significant increase, while the soil moisture exhibits a decrease, after the late 1990s. Furthermore,the normalized difference vegetation index shows an apparent decreasing trend during 1999–2007. Three different drought indices—the standardized precipitation index, the standardized precipitation evapotranspiration index, and the self-calibrating Palmer drought severity index—present pronounced climate anomalies during 1999–2007, indicating dramatic drought exacerbation in the region after the late 1990s. This decadal change in the summer rainfall may be attributable to a wave-like teleconnection pattern from Western Europe to Asia. A set of model sensitivity experiments suggests that the summer warming sea surface temperature in the North Atlantic could induce this teleconnection pattern over Eurasia, resulting in recent drought in the AIP region.     

利用COST-G GRACE时变模型反演黄土高原陆地水储量变化

综合利用COST-G GRACE时变重力场模型、降水、气温、GLDAS模型中地表水、实测浅层地下水和NDVI等多源数据,分析2002-04~2016-12黄土高原陆地水储量的时空变化特征,并利用偏最小二乘回归方法定性分析黄土高原陆地水储量变化的驱动因素。结果表明：1)研究时段内黄土高原陆地水储量具有上升-下降-平缓下降的变化特征,山西省陆地水储量亏损趋势明显;2) 2004~2009年采煤用水、人类生活用水和植被作用是黄土高原陆地水储量下降的重要因素,2010~2016年工业用水、人类生活用水和气温上升是黄土高原陆地水储量下降的重要因素。     

黄土高原末次间冰期气候的不稳定性特征

欧共体格陵兰冰芯计划(GRIP)中的冰芯资料揭示末次间冰期气候具有快速变化的不稳定性特征,而美国格陵兰冰盖计划(GISP2)却不曾发现其不稳定证据。本文通过黄土高原诸剖面的古气候代用指标综合分析认为,末次间冰期,特别是早期气候曾出现过较大幅度的气候波动,存在不稳定性特征,支持了GRIP结果,表明中国黄土含有极地北大西洋的气候信息,是全球变化研究的理想记录。      

川西高原草原地区的金矿成矿元素的表生地球化学特征

通过对川西高原草原地区的东北寨、马脑壳和哲波山金矿区的研究,总结该区的特殊的弱酸性偏还原的表生地球化学特征.并研究不同组元素的贫化和富集,不同粒级、不同深度的元素变化规律,提出金砷锑汞钨等元素是该区金矿的主成矿元素,总结出该区的表生地球化学特征.     

青藏高原的隆起与海洋锶同位素组成的演化

近年来,随着构造隆升驱动气候变化假说的提出,青藏高原的隆起受到越来越多的关注,并将之与大陆化学风化速率及海洋锶同位素的演化紧密联系。围绕青藏高原的隆升及其环境与气候效应,对海洋锶同位素组成的演化特征及其影响因素的较为全面而详细的论述表明:将青藏高原的隆升与全球气候变化、大陆化学风化速率及海洋锶同位素组成的演化相联系,也许是解决目前关于海洋锶同位素组成的演化及其物源问题的重要手段,根据海洋锶同位素的演化历史来研究全球气候变化规律及青藏高原的构造演化历史将是本研究领域的重点。     

高原多年冻土地区公路修筑技术研究的回顾与展望

通过大量的研究课题实例,回顾了高原多年冻土地区公路修筑技术研究的各个历史阶段,综述了公路修筑技术的研究内容和成果。高含冰量冻土分布规律及工程地质研究、冻土路基设计与冻土路基变形规律研究及保持冻土路基稳定性的路基设计原则和工程措施研究、路面修筑技术研究、桥涵基础研究等。随着高原多年冻土地区公路路面等级的提高和路面使用时间的延续及人为因素的不良影响,高原多年冻土地区的公路路基、路面和桥涵等出现了一些新     

Luminescence dating of loessic sediments from the Loess plateau, China

Loess/palaeosol sequences from the Loess plateau in China were investigated by combined infrared optically stimulated luminescence (IRSL) and thermoluminescence (TL) dating techniques in order to study the luminescence properties of the loessic sediments and to provide a direct chronological link for correlation and position of the last interglacial soil in Central Asia and the Loess plateau in China. Sensitivity changes were found for all samples through artificial bleaching of the samples. The greatest sensitivity changes, of up to 50%, were found for very old loess samples designated to be older than the Matu-yama/Brunhes magnetic boundary and hence older than 788,000±1,800 years. The upper dating limit, as investigated by the very old loess samples, ranges from 250,000 to 300,000 years, if the TL additive dose method is applied. The chronological position of the last interglacial soil S1 at the section near Lanzhou indicates luminescence age estimates ranging from 82,000 to 75,000 years for the marine-isotope stage 5 to 4 transition. However, the loess from below S1 yielded luminescence age estimates between 153,200±14,200 and 110,100±20,100 years for TL and IRSL additive dose methods, respectively. Thus, a direct correlation between the S1 and the first intercalated pedocomplex PC1 in Central Asia is most likely. Received: 31 March 1998 / Accepted: 25 October 1998     

青藏羌塘盆地中、新生代火山岩同位素地球化学特征及其意义

通过对羌塘盆地火山岩（含少数侵入岩）的 锶（Sr）、钕（Nd）和铅（Pb）同位素地球化学的研究,获得中、新生代不同类型火山 岩和花岗岩类Sr同位素比值大多数为０706～0710 , 〖HT5”SS〗ε〖HT5”SS〗 N d 值 为-054～-81,均为负值, 206Pb/204Pb值为 171493～ 190313, 207Pb/204Pb值为154350～15666,208Pb/2 04Pb值为 37566~39072。根据同位素地球化学特征,中生代火山岩 物质主要 来源于富集地幔区和下地壳,原始岩浆为壳幔混合型,可能与造山带的岛弧—活动陆缘环 境 有关。早第三纪火山岩岩浆来自富集幔源区,与大陆拉张环境有关。第四纪火山岩形成于高 钾熔岩区内,与俯冲环境有关。总之,本区的火山岩中生代为造山带火山岩,新生代（主要 为早第三纪）为大陆裂谷带火山岩。