Subjects: Geosciences >> Geography submitted time 2023-08-01 Cooperative journals: 《干旱区地理》
Abstract：水分利用效率（WUE）通过联系陆地生态系统碳水循环过程，成为理解植被生态系统对气候变化响应的一个重要指标。结合19902020年的遥感影像与再分析数据产品，基于光能利用效率（CASA）模型反演净初级生产力（NPP）和实际蒸散发（ET）系统分析了19902020年新疆植被WUE的时空变化规律，讨论并探究了影响植被WUE变化的驱动力因子。结果表明：过去31 a新疆植被WUE整体呈下降趋势，但以2003年为转折点，转折点之前呈波动下降趋势，之后呈波动上升趋势。31 a来新疆植被WUE的空间格局没有发生明显变化，高值集中在平原区，特别是绿洲及荒漠-绿洲过渡带，低值集中在山区。通过分析发现，新疆植被WUE变化主要归因于降水、蒸散发及水汽压等气候因子影响。研究结果对于筛选出结构合理、节水性强、生产力高的人工和天然植被结构类型，实现干旱和半干旱地区植被建设的可持续发展具有参考价值，特别是对新疆生态系统安全与农牧业可持续发展具有现实意义。
Subjects: Other Disciplines >> Synthetic discipline submitted time 2023-03-28 Cooperative journals: 《中国科学院院刊》
Abstract： The arid region of Northwest China is one of the driest regions in the world and is characterized with severe water scarcity.Water shortage is the most critical natural factor limiting the high-quality economic and social development and ecological security in the arid region of Northwest China. Based on the long-term monitoring data from the field stations of Chinese Academy of Sciences, observation data of meteorological stations, water resources bulletin and the remote sensing data, this study systematically analyzes the basic characteristics of water resources and ecological environment in the arid region of Northwest China, assesses the changing trends of hydrological elements, water resources, and ecological environment. Besides, this study analyzes the changes of water resources carrying capacity in terms of water use structure and water resources utilization efficiency, and puts forward some suggestions on sustainable water resources utilization and ecological and environmental protection. The results show that the temperature in the arid region of Northwest China has increased at a rate of 0.32℃/decade and precipitation has increased at a rate of 9.32 mm/decade. The glaciers are shrinking at accelerating rate and the runoff supplied by glacier/snow meltwater has increased. The amount of water resources has increased by about 11 billion m3 since the mid-1990s. In the past decade, water use efficiency has been improved, water-saving irrigation area has been expanded, and agricultural water production efficiency has been improved due to water conservation and utilization measures. Water environment capacity has been increased, water carrying capacity has been enhanced, surface water area has been expanded, and the ecosystem condition has improved. However, water resources problems are still prominent in the arid region of Northwest China, the intensity of extreme climate and hydrological events has increased, and the ecological environment is still fragile. In the future, it is necessary to further explore the water resources potential of this region, improve the water resources management, and enhance ecological protection and restoration efforts for better adaptation to the possible risks of climate change, so as to provide scientific and technological support for promoting the construction of the “Green Silk Road” and realizing high-quality regional economic and social development.
Subjects: Geosciences >> Atmospheric Sciences submitted time 2018-10-23 Cooperative journals: 《干旱区地理》
Abstract： 对上海市2012-2016年PM2.5质量浓度、气象因素数据资料进行整理统计，通过定性分析与定量计算相结合的方法，揭示近年来上海市PM2.5浓度的变化特征及其污染状况；进一步地，采用相关性分析，从温度、气压、相对湿度、风向、风速和降水量等方面探讨了PM2.5浓度与气象因素之间的关联性。结果表明，上海市近5年空气质量主要为优和良，污染天数所占全年比例在减少。PM2.5浓度呈现出夏季低，冬季高的季节特征，而且8月PM2.5浓度最低，处于16~36 μg m-3；PM2.5的日变化呈现出双峰双谷结构，浓度峰值出现于8时-9时和19-20时，且后者浓度更高。气温、气压、相对湿度的阈值分别出现在9.8 ℃、766.3 mm Hg、83 %，最大PM2.5在阈值处出现显著变化；最大PM2.5浓度与累积风速和降水量呈现出对数关系，并且东北风和东南风的累积风速达到350 m s-1以上时，PM2.5浓度基本减少至35 μg m-3；降水量越大，PM2.5浓度越低。
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