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电磁感应仪用于土壤盐分空间分布的协同克立格估值研究 被引量:5
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作者 姚荣江 杨劲松 《中国生态农业学报》 CAS CSCD 2008年第1期41-46,共6页
以黄河三角洲地区典型地块为研究对象,应用地统计学的半方差函数理论,分析了0~40cm和40—80cm土壤盐分的空间变异特征。在对协同区域化变量进行交互半方差分析的基础上,采用协同克立格法,以电磁感应仪EM38测得的土壤表观电导率作... 以黄河三角洲地区典型地块为研究对象,应用地统计学的半方差函数理论,分析了0~40cm和40—80cm土壤盐分的空间变异特征。在对协同区域化变量进行交互半方差分析的基础上,采用协同克立格法,以电磁感应仪EM38测得的土壤表观电导率作为协同变量,对各层次的土壤盐分进行估值。结果表明:受结构性因素和随机性因素共同作用,各层次土壤盐分均表现中等强度的变异和空间相关性;随机性因素是引起土壤盐分空间异质性的关键原因;协同区域化变量间均表现为正相关,且协同区域化变量的空间结构优于单一变量。同普通克立格法相比,协同克立格法估值产生的均方误差减小13.1%~17.8%,平均标准误差减小5.83%~17.6%,预测值和实测值间的决定系数提高37.6%~42.6%。该研究结果为黄河三角洲地区土壤盐渍化的精准定量化、科学管理与合理改良提供了一定的理论基础和实践依据。 展开更多
关键词 电磁感应仪 表观电导率 土壤盐分 空间分布 协同克立格 交互半变异函数
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苏北海涂围垦区土壤水分空间变异性及其协同克立格估值 被引量:5
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作者 姚荣江 杨劲松 +3 位作者 邹平 陈小兵 余世鹏 李晓明 《土壤》 CAS CSCD 北大核心 2009年第1期126-132,共7页
以苏北滨海滩涂围垦区为研究区域,应用地统计学方法研究了剖面不同深度土壤含水量的空间变异特征,以0~20cm表土层含水量作为协同变量,分析了不同深度土壤含水量的交互半方差特征,探讨了土壤含水量的普通克立格和协同克立格估值方... 以苏北滨海滩涂围垦区为研究区域,应用地统计学方法研究了剖面不同深度土壤含水量的空间变异特征,以0~20cm表土层含水量作为协同变量,分析了不同深度土壤含水量的交互半方差特征,探讨了土壤含水量的普通克立格和协同克立格估值方法。结果表明:各层土壤含水量都表现为目自变异强度;受结构性因素和随机性因素的共同作用,各土层含水量均呈中等空间自相关性:协同区域化变量间均表现为正相关,且协同区域化变量的空间结构性要优于单一变量;协同克立格对土壤水分局部变异的描述较普通克立格更为详细:与普通克立格法相比,协同克立格法估值产生的均方误差减小10.1%~21.3%,平均标准误差减小11.3%~17.7%,预测值和实测值间的相关系数提高15.9%~26.4%。该研究为滨海滩涂地区土壤水分分区管理和水盐优化调控提供了一定的理论参考。 展开更多
关键词 海涂 含水量 空间变异性 协同克立格 交互半方差
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Effect of Water Salinity on the Spatial Variability of Soil and Plant Parameters
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作者 Ali Ajeel Ali Saeed +3 位作者 Giovanna Dragonetti Alessandro Comegna Nicola Lamaddalena AntonioCoppola 《Journal of Life Sciences》 2015年第11期549-555,共7页
Spatial pattern and interdependence of different soil and plant parameters were examined in green bean field experiment carried out at the Mediterranean Agronomic Institute of Bari (MAIB), Italy. The study aimed to ... Spatial pattern and interdependence of different soil and plant parameters were examined in green bean field experiment carried out at the Mediterranean Agronomic Institute of Bari (MAIB), Italy. The study aimed to identify the spatial distribution of soil and plant parameters and their relationship at transects scale. The experiment consisted of three transects of 30 m length and 4.2 m width, irrigated with three different salinity levels (1 dSm"1, 3 dSm1, 6 dSml). Soil measurements (electrical conductivity and soil water content) were monitored along each transect in 24 sites, using TDR probe installed vertically at soil surface. Water storage was measured by using Diviner sensor for calculating directly the evapotranspiration fluxes along the whole soil profile under the different salinity levels imposed during the experiment. In the same 24 sites, crop monitoring involved measurements of Leaf Area Index (LAI), Osmotic Potential (OP), Root length Density (RID) and Evapotranspiration fluxes (ET). Soil and plant properties were analyzed using both classical and geostatistical methods which included descriptive statistics, semivariograms and cross-semivariograms. Results indicated that moderate to large spatial variability existed across the field for soil and plant parameters, especially under the 6 dSm1 salinity treatment. A relatively satisfactory fit of the experimental cross-semivariogram was obtained for the 6 dS1, thus indicating similar spatial structures of the pairs of compared variables. By contrast, the experimental cross-semivariograms observed under the 3 dS~ treatment indicated no significant correlation structure between the compared variables. Overall, the results observed in the 3 dSm-1 were not significantly different from those obtained in the 1 dSm-1 transect and suggested a general insensitivity of the crop response to those levels of salinity. 展开更多
关键词 Soil and crop properties spatial variability semivariogram cross-semivariogram.
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