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云水含量和云结构参量是天气预报、高山区水循环过程分析的基础。基于2012-2015年夏季CloudSat卫星遥感资料的2B-CLDCLASS、2B-GEOPROF和2B-GEOPROF-LIDAR,结合中国第二次冰川编目数据及气象资料,对祁连山地区疏勒南山冰川区与非冰川区云水含量和云类型特征进行分析。结果表明:(1)云水含量的垂直分布受下垫面和云类型的影响,主要表现为有冰川覆盖的高山上空降水云类型以深对流云为主,无冰川覆盖的高山上空降水云类型以雨层云为主。(2)疏勒南山地区高含水量主要分布在5 km以下的中低层云中,且冰川区气流垂直运动较非冰川区活跃。(3)疏勒南山冰川区云水含量平均值为0.07 g·m^-3,非冰川区云水含量平均值为0.17 g·m^-3,云水的空间变化在一定程度上能够反映降水和水汽的分布状况。 相似文献
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乡村转型是乡村振兴的关键,也是“三农”转型的重要抓手。论文以黄土高原沟壑区甘肃省榆中县为例,从人口转型、土地转型和产业转型3个维度构建乡村转型指标体系,基于2002—2018年统计数据、农户调研数据、遥感数据等多源数据,运用熵值法、层次分析法、乡村转型度模型和空间分析方法,从县域和农户视角,量化与分析榆中县乡村转型及其时空演变格局,刻画农户生计转型路径;在此基础上,引入体制转换理论阐释乡村转型过程机理,并运用逐步回归分析方法识别驱动乡村转型的关键因素。结果表明：① 2002—2018年榆中县乡村转型度、产业转型度和人口转型度明显上升,而土地转型度稳中有降,乡村转型度和产业转型差异明显且变化较大,在中部川区最为突出。② 乡村转型、人口转型、产业转型均呈现“中部川区较高速和高速转型、北部山区低速转型、南部山区由低速转型向较高速过渡转型的空间格局”,并伴有逐级式和跨级式的变化特点,土地转型空间分布较为分散;乡村转型、人口转型、产业转型和土地转型的热点区主要集聚在中部川区,冷点区主要集聚于北部山区。③ 农户生计表现出多路径转型特征,北部山区为综合型生计转型路径,中部川区和南部山区为兼农型生计转型路径。④ 中部川区实现乡村体制转换,南部山区乡村发展明显升级转型,但未形成新的乡村体制,而北部山区乡村转型不够显著。⑤ 固定资产投资是决定榆中县乡村转型的关键因素。研究结果可为乡村转型提供新的研究视角,也为黄土高原沟壑区乡村振兴与乡村高质量发展提供理论依据。 相似文献
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Glacial lakes are not only the important refresh water resources in alpine region, but also act as a trigger of many glacial hazards such as glacial lake outburst flood(GLOF) and debris flow. Therefore, glacial lakes play an important role on the cryosphere, climate change and alpine hazards. In this paper, the issues of glacial lake were systematically discussed, then from the view of glacial lake inventory and glacial lake hazards study, the glacial lake was defined as natural water mainly supplied by modern glacial meltwater or formed in glacier moraine's depression. Furthermore, a complete classification system of glacial lake was proposed based on its formation mechanism, topographic feature and geographical position. Glacial lakes were classified as 6 classes and 8 subclasses, i.e., glacial erosion lake(including cirque lake, glacial valley lake and other glacial erosion lake), moraine-dammed lake(including end moraine-dammed lake, lateral moraine-dammed lake and moraine thaw lake), ice-blocked lake(including advancing glacier-blocked lake and other glacier-blocked lake), supraglacial lake, subglacial lake and other glacial lake. Meanwhile, some corresponding features exhibiting on remote sensing image and quantitative indices for identifying different glacial lake types were proposed in order to build a universal and operational classification system of glacial lake. 相似文献
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