基于不同退耕模式的黄土丘陵区生态环境建设地域分异特征

退耕是目前国家关于黄土丘陵区生态环境建设的主体措施。在总结"赈济退耕25"、"赈济退耕15"和"梯田退耕"各模式基本特点的基础上,根据土地利用、耕地坡度分级数据、农业人口数据和不同模式生态环境建设标准,分别计算了黄土丘陵区各县(市、区)退耕25°和15°以上坡耕地、新建园地、新修梯田、林草植被恢复的面积以及相应的投资需求额度。在构建并采用生态环境建设指数、政策性补贴资金密度指数和投资需求密度指数等指标,对55个县(市、区)进行类型划分的基础上,分析了黄土丘陵区不同退耕模式下的生态环境建设规模及投资需求地域分异特征。     

Coastal processes and cliff recession between Gabicce and Pesaro (northern Adriatic Sea): a case history

Cliff recession on the high rocky coast between Gabicce and Pesaro Adriatic sea causes a wide range of mass movement processes on the whole slope, affecting both the bedrock and the overburden. The outcropping late Miocene rock formations are represented by marls, marly limestones, dark laminated mudstones and bedded sandstones and marls. Mass movements are common because of stratification and discontinuities in the rocks that, together with the presence of groundwater and weathering processes, reduce the overall strength of the slopes. A model for the evolution of this coastal area is proposed, which involves cyclic basal erosion, followed by mass movement that favours debris accumulation at the base of the cliff. The longshore currents have to then remove the material before a new cycle can begin.     

2003年12月1日新疆昭苏6.1级地震烈度与房屋震害

介绍了2003年12月1日新疆昭苏6.1级地震的现场考察结果.该地震宏观震中位于受灾最重的兵团农四师76团11连西侧,极震区烈度为Ⅷ度;圈定出Ⅷ度、Ⅶ度和Ⅵ度3条等震线.此次考察还着重考察了震区各类典型建筑的受损特征,对受损原因作了初步分析,所取得的经验可供类似地区抗震设防和民房改造工作参考.     

Study on the Source Parameters of Earthquakes in the Middle Eastern Area of North Tianshan in Xinjiang

INTRODUCTIONThe study of source parameters is usually based oninversionfromobservational seismic waveformdata.Seismic wave affected bygeometric spreading,inelastic attenuation,scatteringandsite effects ofthe mediumontheir way fromsource to station.Therefo…     

Landscape change and sandy desertification in arid areas: a case study in the Zhangye Region of Gansu Province, China

The Zhangye Region of Gansu Province is an important agricultural base in arid northwestern China. During the twentieth century, especially in the last five decades, the region has experienced sandy desertification. To document the status and causes of this deterioration, satellite images, meteorological and socioeconomic data to assess landscape change from 1993 to 2002 were interpreted and analyzed. The results show that during the intervening 9-year period the area of sandy lands has increased by 642.2 km², which consist of aeolian sand dune (357.1 km²) and potential sandy land (216.3 km²). Although the development and reversion of sandy desertification co-exist, the sandy desertification in this area seems serious and is attributable to the irrational use of water and land.     

Permo-Carboniferous Radiolarians from the Wupata＇erkan Group, Western South Tianshan, Xinjiang, China

The Wupata‘erkan Group, also called Wupata‘erkan Formation, distributed in the South Tianshan, Xinjiang,China, mainly consists of gray and dark gray fine-grained clastic rocks, interlayered with volcanic rocks, carbonates and cherts. Some ultra-basic rocks (blocks) punctuate the formation. The formation was variously assigned to Silurian-Middle Devonian, Silurian-Lower Devonian, and pre-Devonian, mainly based on Atrypa bodini Mansuy, Hypothyridina parallelepipedia (Brour.) and Prismatophyllum hexagonum Yoh collected from the limestone interlayers, respectively.However, radiolarian fossils obtained from 24 chert specimens of the Wupata‘erkan Group, mainly include Albaillella sp.cf. A. undulata Deflandre, Albaillella sp. cf. A. paradoxa Deflandre, Albaillella cf. A. deflandrei Gourmelon, Albaillella sp. cf. A. indensis Won, Albaillella sp. cf. A. excelsa Ishiga, Kito and Imoto, Albaillella sp. and Latentifistulidae gen. et. sp.indet., are earliest Carboniferous and Late Permian. The earliest Carboniferous assemblage is characterized by Albaillella sp. cf. A. undulata Deflandre, Albaillella sp. cf. A. paradoxa Deflandre, Albaillella cf. A. deflandrei Gourmelon and Albaillella sp. cf. A. indensis Won, and the Late Permian assemblage by Albaillella sp. cf. A. excelsa Ishiga, Kito and Imoto. This new stratigraphic evidence indicates that the Wupata‘erkan Group is possibly composed of rocks with different ages from Silurian to Permian, and therefore, it is probably an ophiolite mrlange. The discovery of Late Permian Albaillella sp. cf. A. excelsa provides more reliable evidence supporting the existence of a Permian relic ancient oceanic basin in the western part of Xinjiang South Tianshan.     

古尔班通古特沙漠生物结皮的分布特征

新疆古尔班通古特沙漠是我国最大的固定和半固定沙漠，其间广泛发育着以地衣植物为主的生物结皮，是除种子植物以外的固定沙面的重要生物因子。研究表明，选择适当的时段，应用遥感技术并结合地面调查来研究沙漠生物结皮的空间分布格局是可行的，遥感制图与地面调查的结果基本一致。该沙漠南部是生物结皮最为丰富的区域，各种类型的生物结皮均有充分发育，呈连续分布，但其分布模式向北、向西和向东变得破碎。通过统计生物结皮像元的面积，得到生物结皮覆盖率超过33％的像元面积占研究区总面积的28．7％。生物结皮的分布对地貌部位有较强的选择性，生物结皮的不同发育阶段种类组成亦有较大的差别。     

喀斯特土地利用变化及其区域生态环境效应--以广西都安瑶族自治县为例

从土地利用转移类型、空间格局变化定量分析、动态变化预测模型等方面分析近20年都安土地利用变化,进而对其生态环境质量变化进行定量分析,得出结论:都安各乡(镇)生态环境质量改善与恶化在很大程度取决于裸岩地扩展与收缩,土地利用时空变化与区域生态环境质量的区域差异有很大相关性。     

用叠加谱比法研究新疆地区Lg尾波Q值的区域性变化

运用叠加谱比法,对分布于新疆地区的5个台站所记录的51个地震数据进行分析,得出与各射线路径相对应的Lg尾波Q0(Lg尾波在1Hz处的Q)值。结果表明:Q0值呈现出明显的区域性变化特点,与构造活动关系紧密。在较为稳定的塔里木地台,Q0呈现出高值,在350～450之间。在南部构造活动较为激烈的昆仑褶皱系,Q0呈现出较低的值,约为200～250。在构造活动最为激烈的帕米尔地区,Q0值在170～200之间。在北部的天山褶皱系,Q0值约为220～270。准葛尔褶皱系比天山褶皱系的Q0值略高,约为260～290。     

新疆巴里坤膨润土的工艺应用矿物学特性研究

从工艺矿物学角度系统研究了新疆巴里坤膨润土矿的矿石特征、化学成分、物理性质、矿物组成与结构、工艺应用属性等,认为巴里坤膨润土矿蒙脱石相对含量高,原土适用于石油钻井、铸造和冶金工业,将膨润土深加工后,可制得符合市场需求的有机膨润土、无机凝胶和高纯度蒙脱石等深加工产品.