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精准尺度下麦田土壤特性参数的模型研究 被引量:1
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作者 杨玉建 仝雪芹 《山东农业科学》 2009年第2期8-11,共4页
采用地统计学技术和分形模型方法,对104个麦田观测点进行了土壤速效钾、有机质、碱解氮、速效磷、pH值的空间变异性研究,建立了精准尺度下土壤特性参数空间变异的球状模型,分析了土壤特性参数的分维特征。结果表明,土壤pH值在变程为84.2... 采用地统计学技术和分形模型方法,对104个麦田观测点进行了土壤速效钾、有机质、碱解氮、速效磷、pH值的空间变异性研究,建立了精准尺度下土壤特性参数空间变异的球状模型,分析了土壤特性参数的分维特征。结果表明,土壤pH值在变程为84.271 m的范围内具有强的空间变异性,速效钾、有机质、碱解氮分别在变程为57.691、44.898、45.191 m的范围内具有中等空间变异性,速效磷在变程为23.328 m的范围内呈现弱的空间变异性。土壤特性参数的分维值及空间分布稳定性指数的大小顺序均为pH值>速效钾>碱解氮>有机质>速效磷,其样本间的均一程度及空间分布的稳定性依次降低。 展开更多
关键词 精准尺度 土壤特性参数 空间变异 分形
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河南省土壤墒情监测发展及土壤特性参数测量 被引量:2
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作者 刘冠华 崔亚军 《河南水利与南水北调》 2011年第18期137-139,共3页
河南是农业大省,全省耕地面积为792.6万hm2,居全国第3位,是全国重要的优质农产品生产基地。近几年,河南省连续发生了不同程度的旱灾,影响了粮食生产。河南省水文水资源局自2002年开始,就开始建设土壤墒情监测站点,为抗旱夺丰收提供了科... 河南是农业大省,全省耕地面积为792.6万hm2,居全国第3位,是全国重要的优质农产品生产基地。近几年,河南省连续发生了不同程度的旱灾,影响了粮食生产。河南省水文水资源局自2002年开始,就开始建设土壤墒情监测站点,为抗旱夺丰收提供了科学依据。本文介绍了河南省土壤墒情监测系统的发展以及采用的监测仪器及基本原理,阐述了河南省测量确定土壤田间持水量等特性参数的测量方法。 展开更多
关键词 土壤墒情监测 土壤特性参数 测量
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土壤对滴滴涕的吸附行为及影响因素研究 被引量:2
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作者 刘静 孙金城 +3 位作者 孔令紫 孙翠珍 王刚 徐娜 《山东建筑大学学报》 2010年第5期533-538,共6页
以采自现代黄河三角洲地区不同特性的土壤为研究对象,研究了滴滴涕(DDTs)在土壤中的吸附行为及土壤各特性参数对吸附行为的影响。实验结果表明:DDTs在该地区土壤中的吸附为弱非线性吸附,符合Lang-muir吸附等温方程,分配作用占主导地位;... 以采自现代黄河三角洲地区不同特性的土壤为研究对象,研究了滴滴涕(DDTs)在土壤中的吸附行为及土壤各特性参数对吸附行为的影响。实验结果表明:DDTs在该地区土壤中的吸附为弱非线性吸附,符合Lang-muir吸附等温方程,分配作用占主导地位;影响DDTs的吸附量的主要因素为土壤中有机质含量,其对Langmuir方程中最大吸附量的影响程度可用本文构建的定量方程描述;DDTs的吸附量与土壤的粘粒含量呈正相关,与土壤pH值及土壤可溶解盐含量无明显相关。本研究为构建现代黄河三角洲地区土壤中持久有机污染物的归趋提供数据支持。 展开更多
关键词 滴滴涕(DDTs) 土壤 吸附 LANGMUIR 土壤特性参数
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土壤数据集对全球陆面过程模拟的影响 被引量:6
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作者 李文耀 魏楠 +1 位作者 黄丽娜 上官微 《气候与环境研究》 CSCD 北大核心 2020年第5期555-574,共20页
基于通用陆面模式(Common Land Model,CoLM),首次评估了两套最新的全球土壤数据集GSDE(Global Soil Dataset for Earth System Model)和SG(SoilGrids)对全球陆面过程模拟的影响。比较分析了两套数据中砂粒、粘粒、砾石、有机碳的含量和... 基于通用陆面模式(Common Land Model,CoLM),首次评估了两套最新的全球土壤数据集GSDE(Global Soil Dataset for Earth System Model)和SG(SoilGrids)对全球陆面过程模拟的影响。比较分析了两套数据中砂粒、粘粒、砾石、有机碳的含量和容重这五个土壤属性在全球分布上的差异以及这种差异造成的对模式估计的土壤特性参数、水力热力变量的影响。结果表明,土壤特性参数在全球的空间分布主要受土壤粒径分布(砂粒、粉粒和粘粒)影响,同时也受砾石、有机碳和容重的影响。土壤资料对全球模拟结果影响主要体现在区域差异,对水文学变量的影响(Re最大达到±100%)大于对土壤热力学变量的影响(Re<±10%),对地表辐射变量的影响较小(Re<±5%)。其中,土壤体积含水量在加拿大中部及西北部、俄罗斯东南部及中西部和澳大利亚中部地区模拟结果相差较大,总径流在低纬地区模拟结果出现较大的差异,热力学变量在非洲北部、加拿大西北部以及俄罗斯中北部的差异稍大。将模拟的土壤体积含水量与站点观测相比,两套数据的表现接近,与站点观测相比都存在一定的偏差,但SG更接近观测,其中在Molly Caren站点(39°57′N,83°27′W)上SG相比GSDE整体提高约0.01~0.02。本研究表明,模式模拟结果受不同土壤数据集的影响显著,可优先考虑诸如SG较准确的土壤数据。土壤属性对陆面模拟的影响需进一步研究。 展开更多
关键词 土壤属性 土壤数据 陆面模式 土壤特性参数 土壤体积含水量
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Evaluation of group effect of pile group under dragload embedded in clay 被引量:6
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作者 孔纲强 杨庆 +1 位作者 郑鹏一 栾茂田 《Journal of Central South University》 SCIE EI CAS 2009年第3期503-512,共10页
A simple semi-empirical analysis method for predicting the group effect of pile group under dragload embedded in clay was described assuming an effective influence area around various locations of pile group. Various ... A simple semi-empirical analysis method for predicting the group effect of pile group under dragload embedded in clay was described assuming an effective influence area around various locations of pile group. Various pile and soil parameters such as the array of pile group, spacing of the piles (S), embedment length to diameter ratio of piles (L/D) and the soil properties such as density (γ), angle of internal friction (φ) and pile-soil interface friction coefficient (μ) were considered in the analysis. Model test for dragload of pile group on viscosity soil layer under surface load consolidation conditions was studied. The variations of dragload of pile, resistance of pile tip and the layered settlement of soil with consolidation time were measured. In order to perform comparative analysis, single pile was tested in the same conditions. The predicted group effect values of pile group under dragload were then compared with model test results carried out as a part of the present investigation and also with the values reported in literatures. The predicted values were found to be in good agreement with the measured values, validating the developed analysis method. The model test results show that negative skin friction of pile shaft will reach 80%-90% of its maximum value, when pile-soil relative displacement reaches 2 mm. 展开更多
关键词 pile group effect dragload model tests CLAY
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Pedotransfer Functions for Estimating Soil Hydraulic Properties: A Review 被引量:5
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作者 Nitin Gorakh PATIL Surendra Kumar SINGH 《Pedosphere》 SCIE CAS CSCD 2016年第4期417-430,共14页
Characterization of soil hydraulic properties is important to environment management; however, it is well recognized that it is laborious, time-consuming and expensive to directly measure soil hydraulic properties. Th... Characterization of soil hydraulic properties is important to environment management; however, it is well recognized that it is laborious, time-consuming and expensive to directly measure soil hydraulic properties. This paper reviews the development of pedotransfer functions (PTFs) used as an alternative tool to estimate soil hydraulic properties during the last two decades. Modern soil survey techniques like satellite imagery/remote sensing has been used in developing PTFs. Compared to mechanistic approaches, empirical relationships between physical properties and hydraulic properties have received wide preference for predicting soil hydraulic properties. Many PTFs based on different parametric functions can be found in the literature. A number of researchers have pursued a universal function that can describe water retention characteristics of all types of soils, but no single function can be termed generic though van Cenuchten (VG) function has been the most widely adopted. Most of the reported parametric PTFs focus on estimation of VG parameters to obtain water retention curve (WRC). A number of physical, morphological and chemical properties have been used as predictor variables in PTFs. Conventionally, regression algorithms/techniques (statistical/neurM regression) have been used for calibrating PTFs. However, there are reports of utilizing data mining techniques, e.g., pattern recognition and genetic algorithm. It is inferred that it is critical to refine the data used for calibration to improve the accuracy and reliability of the PTFs. Many statistical indices, including root mean square error (RMSE), index of agreement (d), maximum absolute error (ME), mean absolute error (MAE), coefficient of determination (r2) and correlation coefficient (r), have been used by different researchers to evaluate and validate PTFs. It is argued that being location specific, research interest in PTFs will continue till generic PTFs are developed and validated. In future studies, improved methods will be required to extract information from the existing database. 展开更多
关键词 DATABASE generic PTF hydraulic conductivity predictor properties PTF development tools regression statistical indices water retention curve
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