Subjects: Other Disciplines >> Synthetic discipline submitted time 2023-03-28 Cooperative journals: 《中国科学院院刊》
Abstract： Earth Sciences is a multi-disciplinary science, which takes the interaction of Earth’s various spheres and their resources and environmental effects as the research object. As a comprehensive and systematic science that not only expands the frontier of human knowledge but also serves the social and economic development of human beings, Earth Sciences not only studies the past and reveals the evolution history of the Earth, but also faces the future and provides solutions for the sustainable development of human beings. Based on the analysis of the international development trends of Earth Sciences and the summary of the development status and sci-tech funding of Earth Sciences in China, this study proposed that the future development direction and research plan of Earth Sciences in China should be arranged from the perspective of system science and national needs; and from the perspective of the Earth system as a whole, while attention should be paid to the interaction of various spheres and elements in the Earth system and their influence on the social and economic development of human beings. It is extremely necessary to guide the development directions of Earth Sciences research with “Four Orientations”, carry out major scientific research in an organized way, and improve the mechanisms of sci-tech funding and evaluation, so that the research achievements can better serve the national major strategic needs.
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: Physics >> General Physics: Statistical and Quantum Mechanics, Quantum Information, etc. submitted time 2021-03-02 Cooperative journals: 《干旱区研究》
Abstract：通过对巴丹吉林沙漠周边及腹地进行野外调查采样，归纳出该区植被的生活型和群落类型，分析其植被多样性、优势度及均匀度指数，进而探讨该地区植被群落特征对土壤水分的响应。结果表明：（1）本次调查共记录到20科52属56种植物，分属于乔木、小乔木、灌木、小灌木、半灌木、草质藤本、多年生草本、一年生草本8类生活型，群落多以灌木和多年生草本植物为主，且多为沙漠旱生或超旱生多年生植物；（2）巴丹吉林沙漠群落整体生物多样性指数偏低，沙漠腹地湖泊周围物种丰富度和多样性指数相对较高，边缘地区较低，且灌木层在群落中占优势且分布均匀，草本层植被种类多样；（3）巴丹吉林沙漠土壤含水量普遍较低，超过61%的区域土壤含水量不足5%；土壤含水量与Simpson优势度指数（C）为极显著负相关，与Shannon-Winner多样性指数（H′）、Simpson多样性指数（D）、Alatato均匀度指数（Ea）均为极显著正相关，且Simpson优势度指数（C）、Shannon-Winner多样性指数（H′）、Simp⁃son多样性指数（D）对土壤水分的响应关系中均为立方函数拟合效果最好。
Subjects: Geosciences >> Geography submitted time 2020-12-17 Cooperative journals: 《干旱区研究》
Abstract：为了揭示河西内陆河浅山区小流域的蒸散发及干旱特征，以敦煌西土沟流域为例，利用常规气象数据，通过Penman-Monteith公式计算西土沟流域8个观测站点的潜在蒸散发，再此基础上利用双作物系数法计算出各个观测站点的作物系数，由此计算出实际蒸散发，并计算了该流域的SPEI（标准化降水蒸散发指数）。结果表明：（1）西土沟流域年潜在蒸散发量和实际蒸散发量分别为978 mm、258 mm；上游到下游随海拔下降，潜在蒸散发和实际蒸散发随之呈现不同程度的上升趋势；（2）该流域下游干旱持续时间较长，整个生长季都会出现不同程度的干旱，秋季是干旱发生的主要季节；（3）流域上游的降水量大于实际蒸散发量，中下游实际蒸散发量大于降水量；（4）利用NDVI值计算的作物系数Kc值在实际蒸散发的估算中有较好的适用性，在内陆河浅山区小流域的干旱评估中，干旱指数SPEI比SPI（标准化降水指数）和PDSI（帕尔默干旱指数）指数更有优势。本研究计算出了西土沟流域的潜在和实际蒸散发，并评估了该流域的月尺度及季节尺度的干旱特征，为该流域特别是中下游的生产生活用水提供指导，并得到适用于整个河西内陆河浅山区无资料河流的普适性规律。
Subjects: Environmental Sciences, Resource Sciences >> Basic Disciplines of Environmental Science and Technology submitted time 2018-06-10 Cooperative journals: 《干旱区研究》
Abstract： 外界胁迫条件对植物生长和代谢的影响是多方面的，其中对光合作用的影响尤为突出。植物叶片的光合作用是影响生产力和产量高低的重要因素，因此，植物光合作用及其机制仍是当前植物生理生态领域研究的热点问题。然而，在自然或人工控制条件下，光合作用主要受气孔还是非气孔因子的限制，目前尚无定论。本文从气孔与非气孔限制值的计算方法、不同条件下植物叶片光合作用的气孔与非气孔限制以及对光合作用的影响三个方面展开了讨论：①对（相对）气孔与非气孔限制值的各种计算方法进行了总结，并分析了各种计算方法的局限性，为判断一定条件下光合作用的主要限制因子提供依据。②对以往光合作用的气孔与非气孔限制研究中涉及的外界胁迫条件进行了分类，从人工控制条件（水分胁迫、盐碱胁迫、多因子复合胁迫）及自然条件等方面进行了总结。③分析了气孔与非气孔限制因子对光合作用的影响途径。在未来的研究工作中，揭示和探讨同一物种在不同生长发育阶段、不同生境类型（水热盐养、人工控制与自然环境）等条件下的气孔与非气孔限制因子的变化特征与影响机理，这将是其发展趋势和重点方向。
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