Subjects: Geosciences >> Other Disciplines of Geosciences submitted time 2018-10-23 Cooperative journals: 《干旱区地理》
Abstract: 以虉草幼苗为试材,通过为期50d的室内盆栽控水试验,按照土壤体积水分含量设置7个水分梯度:10±0.5%、15±0.5%、20±0.5%、25±0.5%、30±0.5%、40±0.5%(土壤水分饱和)和51%(淹水2cm),研究了不同土壤水分含量对植物的抗氧化酶活性、丙二醛含量、可溶性蛋白含量的影响。结果表明:(1)土壤水分含量在20%~35%之间时SOD(超氧化物歧化酶)活性较高,低于20%和高于35%时,SOD活性下降,且在不同土壤水分含量下试验50 d的SOD活性均大于试验25 d的;(2)CAT(过氧化氢酶)与POD(过氧化物酶)活性达极显著相关p<0.01,均随土壤水分含量的增加呈先大幅下降后平稳再小幅上升的趋势;(3)MDA(丙二醛)含量与SOD活性趋势相反,随土壤水分含量的增加不断下降,在试验25 d时淹水组略有上升;(4)可溶性蛋白在20%到40%之间时含量较高,植株生长状况较好,在干旱和淹水胁迫条件下可溶性蛋白含量呈下降趋势。由此可见:当虉草幼苗受到干旱等胁迫时,虉草幼苗会开启抗氧化酶系统以保护植株组织,可长时间的胁迫或者胁迫超过其耐受范围(土壤水分含量小于20%或处于土壤水分过饱和淹水条件)就会不同程度的破坏植物的防御系统从而影响其生长发育。
Subjects: Geosciences >> Geography submitted time 2024-03-01 Cooperative journals: 《干旱区研究》
Abstract: Precipitation acts as a crucial supply for mountain glaciers, and its water vapor source closely correlates to the amount of precipitation. This study focuses on the modern glacier distribution area of Ulugh Muztagh in the eastern Kunlun Mountains, analyzing water vapor sources in the region from 2005 to 2022 using the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model and the Global Data Assimilation System (GDAS). Employing backward trajectory analysis, we reveal the source and regularity of water vapor in the Ulugh Muztagh region and discuss its seasonal changes. The results show that the water vapor source in the Ulugh Muztagh area mainly extends to the Eurasian interior along the midlatitude westerly belt and is divided into three routes entering the Qinghai-Tibet Plateau from the Tianshan Mountains, the Pamir Plateau, and over the high-altitude stratosphere. On the Qinghai-Tibet Plateau, water vapor from the Indian Ocean either moves northward over the Himalayas or turns northwestward to merge with the westerly circulation into the plateau’s hinterland. Land-source water vapor, entering from the Pamir Plateau and Tianshan Mountains, accounts for 62.52% of the total water vapor in the Ulugh Muztagh area. Meanwhile, sea source water vapor, comprising high-altitude water vapor from the westerly belt (Atlantic water vapor) and the Indian Ocean, accounts for 37.48% of the total water vapor. Notably, we find that the proportion of water vapor from the sea source has increased steadily over recent decades. Analyzing multiyear seasonal averages for water vapor, we find a notably high proportion of locally recycled water vapor in the summer, comprising 22.64% of the total. This study’s outcomes offer valuable insights into the water cycle dynamics of the Ulugh Muztagh area in the East Kunlun Mountains.
Subjects: Geosciences >> Geography submitted time 2024-12-03
Abstract:以东昆仑鲸鱼湖流域为研究区,通过解译Landsat系列影像获取1990—2023年流域内冰川和湖泊范围,同时利用内陆水域水文时间序列数据库水位数据集和全球冰川物质平衡数据集,分析鲸鱼湖流域冰川面积、储量和物质平衡及鲸鱼湖面积、水位和储量变化特征。此外,结合ERA5再分析资料,探讨流域内冰川和湖泊的变化,及其对气候变化的响应过程。结果表明:(1) 1990—2023年,鲸鱼湖呈现显著扩张趋势,从266.00 km2扩张至399.30 km2,面积扩张了133.30 km2,扩张速率为4.66 km2·a-1;2013—2023年湖泊水位上升5.19 m,水位上升速率为0.55 m·a-1;湖泊水量增加1.31 km3,年增量为0.16 km3。(2) 1990—2023 年流域内冰川呈现显著退缩趋势,冰川面积减小4.59 km2,变化速率为-0.12 km2·a-1,冰川储量减少0.38 km3,变化速率为-0.01 km3·a-1;2000—2020年冰川多年平均物质平衡为-1.22×10-4 m w.e.。(3) 1990—2021年流域内年平均气温显著升高,年升温率为0.02 ℃·a-1,但是夏季升温不显著。年降水量显著增多,速率为2.11 mm·a-1,降水集中在夏季,夏季降水量占年降水量的78.9%。(4) 流域内降水是导致湖泊扩张的主要因素。研究揭示了鲸鱼湖流域冰川、湖泊对气候变化的响应,可为当地政府优化水资源配置和管理提供参考。
Peer Review Status:Awaiting Review