Results 31 to 40 of about 3,276 (165)
采用定位取样与烘干法,测定了榆林沙区几个树种土壤含水量。结果表明:各树种土壤含水量变化规律为:樟子松>柠条>紫穗槐>沙柳>沙蒿>花棒-踏郎;土壤含水量的垂直分布格局为表层土壤含水量最低,随着土壤深度的增加,土壤含水量呈增加趋势;土壤含水量的季节动态规律为不同树种土壤含水量具有明显的季节变化规律,土壤含水量按季节变化可分为3个阶段,4-5月的土壤水分弱失水阶段,6-8月的土壤水分消耗阶段,9-10月的土壤水分缓慢恢复阶段。
尚爱军 +4 more
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为探究不同前期土壤含水量条件下坡面产流产沙特征及产流产沙关系,以安塞黄绵土为研究对象,通过设置6个前期土壤含水量处理(5%,10%,15%,20%,25%,30%),采用室内人工模拟降雨试验来系统研究前期土壤含水量对坡面产流产沙过程的影响。每个含水量处理设置2个重复,坡面坡度为15°,设计雨强为90 mm/h,降雨历时为1 h。结果表明:(1)随着前期土壤含水量的升高,坡面初始产流时间幂函数减小,产流量线性增大。(2)坡面土壤流失量随前期土壤含水量增大呈幂函数增加,高含水量组(29.3 ...
淡彩虹 +5 more
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Remote sensing estimation on regional continuous daily evapotranspiration based on Richards equation [PDF]
Evapotranspiration (ET) is an important part of water cycle in nature, and the estimation of evapotranspiration on spatio-temporal scale has always been a hot issue. Remote sensing can estimate evapotranspiration on regional scale, but it is difficult to
Jinling KONG +4 more
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Effects of drying-wetting cycle caused by rainfall on soil respiration: Progress and prospect [PDF]
Soil respiration is an important part of the carbon cycle in terrestrial ecosystems. The changes of soil respiration caused by rainfall directly affect global carbon balance.
朱连奇 +3 more
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快速准确获取表层土壤水分是土壤学、生态学及相关学科研究的基础.该研究在室内条件下,研究了5种不同土壤表面灰度值与含水量之间的关系,以期为利用土壤表面灰度值反演表层土壤含水量建立试验基础.研究结果表明:土壤在烘干过程中,含水量的变化受孔隙结构的影响;对于不同类型的土壤,土壤表面灰度值受矿物质组成和有机质含量的影响,随着土壤有机质含量的增加,同一含水量下的土壤表面灰度值降低;土壤表面灰度值与表层土壤含水量呈指数负相关关系.
毛天旭, 朱元骏, 邵明安
doaj
黄土丘陵区土壤有机碳含量对侵蚀坡面表层土壤含水量时空变化的影响
表层土壤含水量能敏感反映降雨、气温、侵蚀等环境要素的变化,明确表层土壤含水量时空变化特征可为农业生产及土壤环境效应评价等提供参考。以黄土丘陵区不同有机碳水平的侵蚀坡面为对象,连续监测了2016年11月至2018年3月0-5 cm土壤含水量的动态变化,结合降水资料,分析了不同土壤有机碳水平下侵蚀坡面沉积区、侵蚀区及对照区表层土壤含水量的变化特征。结果表明:(1)表层土壤含水量不同季节变化差异显著,夏季变幅最大,单日最大变幅可达14.3%,春、秋、冬季的单日最大变幅 侵蚀区 > 对照(未侵蚀)区 ...
夏彬, 朱世硕, 郝旺林, 许明祥
doaj
Relationship between riparian plant diversity and soil factors in the middle and lower reaches of the Yellow River [PDF]
[Objective] The relationship between species diversity and soil factors in riparian zone is important to maintain the stability of riparian ecosystems. The purpose of the study is to reveal the relationship between species diversity and soil factors in
LI Ya +3 more
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Natural Vegetation Succession Characteristics and Influencing Factors for Reclamation Area of Tianjin City [PDF]
[Objective] The natural vegetation succession characteristics and influencing factors for a reclamation area in Tianjin City were studied in order to provide a scientific basis for ecological restoration and reconstruction of the reclamation area ...
Gao Yue, Li Hongyuan, Luo Li
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不同土壤前期含水量对土壤分离临界水动力学特性及其抗剪强度的影响
坡面土壤分离临界水动力参数的定量描述对完善土壤侵蚀物理模型具有重要意义。通过实测不同土壤前期含水量(5%~23%)和坡度(1°~10°)条件下黄壤坡面土壤分离临界水动力参数,并结合不同土壤含水量(3%~23%)对土壤抗剪强度的影响,综合分析及探讨不同土壤前期含水量、坡度和土壤抗剪强度与临界水动力特性的关系。结果表明:临界流量与不同土壤前期含水量和坡度呈幂函数减小关系,提出一种能够体现土壤前期含水量和坡度共同作用对临界水动力参数影响的预测方程。在坡度小于5°时,土壤前期含水量对临界水动力学参数影响较小 ...
王晨沣, 王玉杰, 王云琦, 胡
doaj
本文讨论了土壤含水量和蒸散量对牧草生长量的影响过程,提出牧草干物质增长模式,并根据青海海北高寒草甸地区的气象条件,对牧草生长量模式进行数值模拟,同时,与实测值进行比较,模拟结果与实测值趋向一致 ...
周兴民 +5 more
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