Formation and evolution of sand deserts in Xinjiang,Northwest China: I. Provenances ofdesert sands简     

ZHU Bingqi  YU Jingjie  QIN Xiaoguang  Patrick RIOUAL  LIU Ziting  XIONG Heigang 《地理学报(英文版)》2014,24(1):177-190

Sandy desert landscape is a geological product of arid climate and abundant sand materials supply in natural conditions, therefore the formation of sandy desert is an ideal studying object for understanding the interaction between various stratigraphic/epigenetic spheres of the earth system. However, until now, the knowledge about the provenance and formation of these deserts in Xinjiang, Central Asia is diverse and inconsistent, a systematic review is necessary. Ancient aeolian sand sediments in the internal areas of these deserts and their twin dust deposits in the Cenozoic strata surrounding the Xinjiang deserts are direct and indirect clues reflecting the provenance of sand materials and the formation and evolution of deserts. Based on the geochemical, mineralogical and isotopic evidences of desert sands and relevant deposits in the peripheral regions, this paper reviews the research progress on the development of the sandy deserts in Xinjiang, Northwest China. Many proofs proposed that desert sands in Xinjiang were mainly sourced from the ancient pluvial, alluvial and fluvial sediments and were eventually achieved because of the local sand supply. It pointed out that the settings of tectonic structure in Xinjiang had made sediments both in the Tarim Basin and the Junggar Basin being influenced greatly by regional hydrological system and aeolian processes originated from the planetary wind system of westerly, the East Asian winter monsoon and the topographical mountain-valley winds. However, the directions of transpor- tation paths are different between the hydrological dynamics and the aeolian dynamics, which are decided by the slantwise structures of the basins tectonics and the regional atmospheric circulation routes, respectively, and have determined anisotropies of the transport pathway of these sediments delivered by different agents. This results in a geological cycle of detrital sediment transportation in the two large sediment mixing, alternation and recycle basins and thus largely increases the degree of between younger and older sediment sources, as well as the complexity and diversity of sand provenances.  相似文献   

小型化体积式钻孔应变仪的研制     

马京杰  李海亮 《大地测量与地球动力学》2021,41(2):207-220

体积式钻孔应变仪力学原理简单,易于获取可靠资料,但受尺寸限制。现有TJ-2型体应变仪的安装钻孔直径必须大于130 mm,钻孔成本较大,为减少钻孔经费,本文对体积式钻孔应变仪的小型化进行研究,计算体积式钻孔应变仪的灵敏系数和视压缩模量,并根据结果结合材料工艺,研制钻孔直径为110 mm的应变仪。  相似文献   

缺测站干旱流域生态输水遥感监测与农业节水效益分析          下载免费PDF全文

潘子豪  杨胜天  娄和震  于静洁  王忠静  张军 《干旱区地理》2022,45(3):774-785

生态输水与农业节水是实现内陆干旱流域可持续发展的重要手段,连续水文观测资料的缺乏制约了生态输水与农业节水效益评价。为此,以中国甘肃敦煌疏勒河流域下游为例,基于遥感水文站与谷歌地球引擎进行2016—2020年月尺度的生态输水遥感监测,在此基础上结合蒸散发和土地覆盖类型等多源遥感数据评价生态输水与农业节水效益,分析两者之间在水资源方面的平衡关系。结果表明：（1） 遥感水文站与谷歌地球引擎（Google Earth Engine, GEE）能够为生态输水遥感监测与农业节水效益评价提供可靠的数据支撑。（2） 2017—2020年生态输水能够为下游湿地与河道平均每年提供2.50×10⁸ m³生态用水,其中30.06%的水量到达下游湿地,18.47%的水量被下游河道周边的植被所利用,且使下游河道周边植被面积增加112.25 km²。（3） 农业节水在保持耕地面积维持上升趋势的前提下,2017—2020年平均每年降低耕地的蒸散发量0.395×10⁸ m³;耕地蒸散发减少量平均占生态输水量的14.22%,农业节水有效缓解了内陆干旱流域农业用水挤占生态用水的问题。本文将为内陆干旱缺测站流域的生态输水遥感监测与农业节水效益评价提供新的思路,以期为未来的生态输水与农业节水工程的实施提供理论支撑。  相似文献   

岩石非弹性应变恢复(ASR)地应力测试方法中柔度研究进展评述     

马秀敏  彭华  白金朋  李振  姜景捷 《地质力学学报》2017,23(4):526-530

本文通过分析国内外非弹性应变恢复(ASR)法地应力测量研究现状,并对ASR法中重要的柔度参数作了系统整理,认为该测量方法在理论上逐渐趋于成熟,在技术应用上有广阔的前景,但该地应力测量原理中,针对温度、应力环境(作用应力)对ASR岩石柔度影响的研究相对较少,还存在一些缺陷,为此提出了该地应力测试方法有待改进或补充的建议,为完善ASR法地应力测量原理指明了研究方向,对今后ASR地应力测量技术的完善和发展具有重要的意义。  相似文献   

珠三角地区城镇化与生态韧性的耦合协调研究   总被引：3，自引：0，他引：3  

王少剑  崔子恬  林靖杰  谢金燕  苏坤 《地理学报》2021,76(4):973-991

城市韧性是新兴的研究话题,其实质为城市面对不确定性扰动的抵抗、恢复及适应能力.本文构建“规模-密度-形态”三维城市生态韧性评价体系,借鉴物理学耦合模型测算2000-2015年珠三角城市城镇化与生态韧性的耦合协调度,并对其时空变化特征进行深入探讨.结果 表明:2000-2015年珠三角各市的城镇化水平总体不断提升,生态韧...  相似文献