Results 71 to 80 of about 1,183 (154)
Shuitu Baochi Xuebao, 2007 非饱和土壤水分扩散率是研究土壤水分运动规律必不可少的基本参数之一。本文应用水平土柱入渗法测定了科尔沁沙地沙质农田表层土壤的非饱和水分扩散率,并对氯化钴试纸在测定水分扩散率中的应用作了初步尝试和研究。主要结论如下:沙质农田表层土壤湿润锋迁移速率随着入渗距离的增大而减小,呈幂函数关系;波尔兹曼参数与土壤含水量呈直线关系;土壤水分扩散率与土壤含水量之间的关系,符合经验公式并呈指数函数变化。在应用水平土柱法测定非饱和土壤水分扩散率的过程中,氯化钴试纸法可以用于测定湿润锋的位置,特别是在高土壤含水量时 ...
刘新平 +6 more
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Shuitu Baochi Xuebao, 2018 通过室内一维垂直土柱试验，利用TDR和张力计分别研究土壤中纳米碳混合层对土壤水分入渗特性、土壤水分分布以及纳米碳混合层对土壤水分特征曲线的影响。结果表明：（1）随着入渗时间的增加，含有纳米碳的土壤在相同入渗时间内累积入渗量减少，湿润锋推进距离明显减小，施加纳米碳具有明显的减渗作用。利用Philip入渗模型拟合入渗数据，吸渗率S随着纳米碳含量的增加而减小，随着纳米碳含量的增加，水分入渗初期的累积入渗量逐渐减小。对湿润锋分层进行线性拟合，在湿润锋进入第2层土壤时，入渗速率有了显著的降低 ...
薛文强 +4 more
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Shuitu Baochi Xuebao, 2021 基于3年连续冬小麦-夏玉米覆膜轮作试验，通过校验之后的AquaCrop模型设置不同水平的播前土壤墒情，模拟研究关中地区多年历史气候条件下旱作覆膜夏玉米生长和水分利用对播前土壤墒情的响应规律，拟基于播前土壤墒情初步建立覆膜与否的判断标准。结果表明，当土壤初始含水率≤70%田间持水量，关中地区夏玉米覆膜产量波动剧烈；覆膜增产率随着降水的增加呈增加趋势。随着土壤初始含水率的增加，覆膜增产效果越来越明显，且趋于稳定；然而覆膜措施的增产效果对降水量越来越不敏感，最终呈稳定趋势。当播前土壤底墒达到80%~85 ...
徐志鹏 +7 more
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Research on risk early warning for rainfall-induced shallow landslides in Guangdong Province based on a dynamic slope instability model [PDF]
In light of the accuracy and model construction challenges in county-level meteorological risk early warning for geo-hazards, and considering the prominent characteristics that these geo-hazards mainly occur on the shallow surface of residual slopes, the
Pingxin WEI +5 more
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Shuitu Baochi Xuebao, 2008 为了探讨温室作物生产水肥管理和温度环境对土壤NO3--N向表层迁移的影响,选用5 a的温室土壤样品进行土柱蒸发模拟试验,研究蒸发温度、土壤初始含水量、初始NO3--N含量及其耦合效应对温室土壤迁移速率及其垂直剖面分布的影响。试验结果表明:蒸发温度和土壤初始含水量明显影响NO3--N向土壤表层的迁移,并随蒸发温度和土壤初始含水量的增加而加强;通过正交回归分析得出影响NO3--N迁移速率的因素依次为初始含水量、蒸发温度以及温度与含水量的交互作用;土壤初始NO3--N含量以及它与蒸发温度 ...
袁巧霞, 武雅娟, 朱端卫
doaj
Characteristics and Influencing Factors of Soil CH4 and N2O Fluxes in Typical Broad-leaved Forests in the Yangtze River Delta Region, China [PDF]
[Objective] The forest coverage rate in the Yangtze River Delta region reaches 33.4%, and the underlying surface soil may have an important impact on the regional greenhouse gas budget.
CHEN Bingjiang +7 more
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Shuitu Baochi Xuebao, 2004 根据直线和网格布点法布置的150个取样点的测定资料，应用经典统计分析方法．探讨了垦荒地土壤电导率和重量含水率的空间变异性，并给出了不同置信水平及精度要求下两者的合理取样数目。应用自相关和半方差分析方法进一步讨论了土壤电导率及土壤重量含水率的空间变异结构和半方差函数模型。结果表明，垦荒地土壤电导率和重量含水率的空间变异都是有结构的，土壤电导率的最大相关域为9m，土壤重量含水率的最大相关域为6．4m。两者的半方差函数可用有基台的线型模型拟合。
胡顺军 康绍忠 宋郁东 田长彦 王方
doaj
Ecological protection coal mining technology system and engineering practice [PDF]
In view of the large-scale and efficient coal mining in ecologically fragile areas, which causes a large scope, long cycle and high intensity of ecological impacts, and the lack of a systematic technology that integrates the whole cycle of mining, source
Jie FANG +6 more
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Differences in Burrow Morphology of the Mud Shore Crabs between Spartina alterniflora and Mangroves [PDF]
, 2011 本实验用聚酯树脂浇塑法制备了云霄红树林区光滩、互花米草群落、白骨壤群落、秋茄群落和桐花树群落五个生境内蟹洞的形态模型，并测量了蟹洞的密度、开口直径、深度、分支数、单位面积内蟹洞总体积五个形态参数，并对五个生境中每种蟹洞形态参数进行了单因子方差分析(One-WayANOVA)。同时测定了五个生境中植物群落参数、土壤理化性质、植物根系密度及植物叶片中单宁含量等环境因子，并对不同的环境因子与蟹洞的各形态参数进行了相关性分析，并根据相关性分析的结果推断每个生境中影响蟹洞形态的主要环境因子 ...
高雪芹
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Study on the effect of layered structure of overlying strata on soil damage in mining areas in the loess covered region of northern Shaanxi [PDF]
Ecological protection in coal mining areas is a major problem that needs to be solved urgently for high-quality development in the Yellow River Basin. Scientific understanding of the response law of the overlying strata of the coal seam to the surface ...
Jiangbo WEI +7 more
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