共查询到19条相似文献，搜索用时 593 毫秒
1.
基于全卷积网络的土壤断层扫描图像中孔隙分割 总被引：5，自引：5，他引：0
针对土壤断层扫描图像中存在部分容积效应及因孔隙成分复杂、结构不规则等引起的分割精度低的问题,该文提出一种全卷积网络(fully convolutional network,FCN)土壤孔隙分割方法,为土壤科学研究提供技术支持。该文以黑土土壤断层扫描图像为研究对象,通过卷积和池化运算输出不同尺度的孔隙特征图;将孔隙的深层特征和浅层特征相融合,采用上采样算子对融合特征进行插值操作,从而输出孔隙的二值图。与大津法、分水岭法、区域生长法和模糊C均值聚类法(Fuzzy C-means,FCM)4种常用孔隙分割方法的对比结果表明,FCN法在低,中,高3种孔隙密度的土壤图像中优于其他4种方法。FCN法的平均分割正确率为98.1%,比4种常用方法分别高25.6%,48.3%,55.7%和9.5%;FCN法的平均过分割率和欠分割率分别为2.2%和1.3%,仅为次优方法(FCM法)的33.8%和23.6%。通过融合土壤孔隙结构的多重特征,FCN法能够实现土壤孔隙整体和局部信息的精准判断,为土壤学的研究提供了一种更加智能化的技术手段。 相似文献
2.
采用染色示踪技术的土壤优先流自动分割与量化系统 总被引：4，自引：3，他引：1
针对土壤染色图像色度不一致、染色/非染色区域对比度低的特点,以及现有土壤染色图像分割方法自动化程度弱的问题,该研究提出一种土壤优先流自动分割与量化系统。该系统采用基于H分量改进的模糊C均值方法(Fuzzy C-Means Based on H Component and Morphology,HM-FCM)实现染色区域的自动分割,运用数学统计法提取总染色面积比、基质流深度、优先流比等特征参数,实现对土壤染色区域的量化分析,以揭示优先流的发育程度。并基于2种林地染色图像验证了系统性能。试验结果表明:1)HM-FCM法对于天然次生林和榛子林图像均具有最佳分割效果,其分割准确率为87.9%和83.3%,调和平均值为90.5%和80.3%;2)2种林地土壤染色区域总体集中于0～50 cm土层,优先流具有不同发育程度(P0.05)。该系统可为优先流路径的空间演变提供技术支持和理论依据。 相似文献
3.
针对现有青藏高原光核桃种核表型主要采用手工测量和目视法获得，操作繁琐，且提取参数种类有限的问题，该研究构建了一种基于HSV（Hue，Saturation，Value）空间和拟合椭圆的光核桃种核表型自动量化系统。该系统包括图像自动分割和多重参数提取2个部分，首先，采用HSV阈值法实现光核桃种核图像的精准分割；其次，用拟合椭圆法进行光核桃种核的核尖提取；最后，对光核桃种核形态、颜色、纹理3类表型进行定量描述。结果表明，该系统对光核桃种核的自动分割准确率达到99.7%，且能够实现多种表型的自动、准确量化，为光核桃表型参数研究提供数据基础和技术支持。 相似文献
4.
基于序列信息的土壤CT图像超分辨率重建 总被引：1，自引：1，他引：0
受部分容积效应影响,土壤计算机断层扫描（Computed Tomography,CT）图像存在孔隙边界模糊现象,影响土壤孔隙结构研究的准确性。针对该问题,该研究提出基于序列信息的生成式对抗网络（Sequence information Generative Adversarial Network,SeqGAN）,实现土壤CT图像的超分辨率重建。针对土壤CT序列图像具有较高相似性的特点,SeqGAN法引入序列卷积块挖掘前后图像的序列信息,并将多重特征增强融合于目标图像中;利用多层残差块提取图像特征,构建残差块输入和输出的直接连接,以减少模型退化;利用对抗网络实现损失间接反馈,提高模型的特征学习能力。在序列相似性较高的土壤图像数据集验证了该方法性能。结果表明,SeqGAN法均方误差比次优方法GAN降低25%,峰值信噪比提升1.4 dB,结构相似性提升0.2%。重建的土壤图像具有较高准确率和清晰度,可为后续土壤物理学研究提供准确的数据基础。 相似文献
5.
不同利用年限的红壤水稻土孔隙结构差异的图像分析 总被引：11，自引：0，他引：11
本文利用目前常用的土壤孔隙结构研究方法,获取了不同利用年限的红壤水稻土在风干状态下的孔隙结构图像,对孔隙结构特征的图像分析结果表明,随着利用年限的延续,孔隙结构逐渐改善,表现在孔隙面积逐渐增加,孔隙的孔径分布和孔隙在土体中的分布逐渐均匀,孔隙中大孔隙比重逐渐增大等方面。 相似文献
6.
利用染色示踪和图像处理技术对土壤大孔隙进行定量研究 总被引：2，自引：0，他引：2
以太湖地区水稻土为例介绍了染色示踪和图像处理技术在土壤大孔隙定量化研究中的应用.剖面染色的区域是孔隙存在的地方,孔隙的孔径越大,充斥的染料溶液就越多,所染的颜色就越深.据此利用地理信息系统软件ArcGIS和遥感图像处理软件ERDAS对土壤剖面图像进行处理并进行颜色分级.从分级结果中提取代表土壤大孔隙的部分,计算大孔隙的含量.所得结果与土壤各层次的孔隙度、黏粒含量、饱和导水率变化趋势有很好的一致性.并且本文还对染色示踪法土壤孔隙定量的影响因素进行讨论. 相似文献
7.
用于研究土壤孔隙三维结构的连续数字图像的制备 总被引：16，自引：1，他引：16
主要介绍了一种用于分析土壤孔隙三维结构的连续数字图像的制备方法，内容包括土样的处理、不同格式图像之间的转换、孔隙结构分析指标等；对一类具体土壤的研究结果表明，在2cm的间距内，土壤孔隙结构仍存在较为明显的异质性。 相似文献
8.
利用基于偏微分方程的图像滤波技术研究土壤孔隙结构 总被引：6，自引：4，他引：2
利用自主研发的土壤切片数字图像处理分析系统软件,采用3种滤波方式,即BMO滤波(boundary mean oscillation有界平均振荡模型)、PM滤波(Perona-Malik偏微分方程模型)和中值滤波,对免耕、翻耕和旋耕3种耕作方式下不同深度土壤切片的数字图像进行去噪增强,并对处理后的图像进行了孔隙特征参数提取与统计。在此基础上,探讨了几种图像滤波技术的效果以及耕作方式对不同土层土壤孔隙形态结构的影响,以期找到适用于土壤切片数字图像的滤波技术,为后期土壤孔隙信息的提取与统计提供工具。结果表明,采用BMO滤波后,从土壤切片数字图像得到的土壤孔隙度与试验结果最为接近;其中,孔径5μm的孔隙度显著大于其他图像滤波技术的结果,而5~50μm与50μm孔径的孔隙度与其他图像滤波技术的结果没有显著差异;与免耕相比,翻耕与旋耕提高了表层土壤的孔隙度,增加了传导孔隙的比例。 相似文献
9.
针对木质部交互统计误差大、效率低、重现性差、劳动强度高和传统图像处理算法精度不理想等问题,该文以狭叶锦鸡儿木质部切片图像为研究对象,根据木质部特点提出基于K均值聚类算法和环形结构提取算法相结合,实现木质部准确提取的方法。首先通过动态巴特沃斯同态滤波法对30幅供试图像进行光照不均校正,然后采用K均值聚类法对光照补偿后图像初分割,最后采用环形结构提取算法实现木质部提取计数。试验结果表明:采用K均值聚类算法对光照补偿后的木质部图像初分割分割误差R(section error, R)、过分割误差OR(over-segmentation error, OR)和欠分割误差UR(under-segmentation error, UR)均值分别为5.15%、1.48%和6.46%,优于未光照补偿和3R-G-B算法;该文提出的环形结构提取算法对初分割后木质部图像检测的平均相对误差为2.26%,比分水岭法低11.69个百分点,比凹点匹配法低4.93个百分点。从速度上看,该算法平均耗时3.17 s,比分水岭法快1.40 s,比凹点匹配法快4.88 s。该算法检测的均方根误差RMSE(root mean squared error, RMSE)为0.52%,约相当于分水岭法的1/3,约相当于凹点匹配法的1/2,该算法优于其他2种分割算法;在图像结构复杂、光照不均匀、内部分布不均等缺陷条件下,该文算法也能很好地实现木质部的分割和提取。该方法不仅能对狭叶锦鸡儿木质部自动分割和提取,也可为其他植物木质部分割提取提供参考。 相似文献
10.
农田土壤孔隙及其影响因素研究进展 总被引：6，自引：1，他引：5
《土壤通报》2015,(1):233-238
土壤孔隙是土壤结构的重要组成部分,是衡量土壤质量的重要指标之一。土壤孔隙的数量及大小分布直接决定着土壤的透气性、持水保水性能以及作物根系在土壤空间的伸展,间接影响土壤的肥力和作物产量。基于前人研究基础,系统介绍了土壤孔隙的类型和分类方法、定量研究技术及其主要的影响因素,并对未来土壤孔隙研究的重点进行了展望,以期为今后土壤孔隙结构的深入研究提供帮助,指导人们采取合理的农业管理措施。 相似文献
11.
土壤是地球表面由固、液、气三相组成的疏松多孔介质体,土壤物理、化学和生物学等过程主要发生在液相和气相填充的土壤孔隙中及其与固相的交界面。随着无损探测土壤孔隙结构、土壤生物化学原位分析和计算机模拟等技术的快速发展和计算能力的提升,从土壤孔隙的形态、结构和功能的角度,原位、直观、精确地研究土壤中动态发生的各种过程成为可能,推动了对真实土壤中各种微观过程与机制的研究。基于前期的研究进展,本文提出,研究透明土壤体的物理学—土壤孔隙学（Soilporelogy）的时代已经启航。土壤孔隙学主要针对土壤孔隙空间,研究其动态变化与土壤物理、土壤化学和土壤生物（生态）互作过程及其效应。以土壤孔隙学为主线,本文首先介绍了获取土壤孔隙方法的进步,进而论述了基于土壤孔隙的流体运动、生物化学过程、根系和生物活动以及土壤微观生态学等的试验和模拟研究。最后,本文对土壤孔隙学的研究方法和理论发展方向进行了展望,相信基于土壤孔隙的研究会推动土壤学研究新的发展。 相似文献
12.
Soil hydraulic properties as related to soil structure 总被引：5，自引：0，他引：5
13.
利用计算机断层扫描技术研究土壤改良措施下土壤孔隙 总被引：12，自引：5，他引：7
为探明不同土壤结构改良措施（秸秆覆盖、免耕、有机肥、保水剂）对土壤孔隙特征及分布的影响,采用计算机断层（computed tomography,CT）扫描法定量分析了土壤孔隙的数目、孔隙度及孔隙在土壤剖面上的分布特征。结果表明：不同措施均提高了土壤总孔隙数、大孔隙数及0.13～1.0 mm孔隙数,且其孔隙度也相应提高。同时孔隙成圆率也得到了改善。各处理中以有机肥和免耕处理效果较佳,其次为保水剂和秸秆覆盖,对照最低。此外,不同措施显著提高了土壤的田间持水量和＞0.25 mm 水稳性团聚体含量,降低了土壤容重,且各处理中,仍以有机肥和免耕处理效果最佳,其田间持水量分别较对照提高了15.9%和16.4%,而土壤容重较对照降低了6.8%和8.8%。相关分析表明：田间持水量、容重和＞0.25 mm水稳性团聚体含量与土壤总孔隙度和大孔隙度呈显著或极显著正相关;而土壤容重对于总孔隙度和大孔隙度及孔隙成圆率呈显著负相关。 相似文献
14.
The physical characteristics of the soil surface are of extreme importance in relation to energy and matter transfer processes between the atmosphere and the soil. Soil internal structure changes can be due to natural or artificial causes and one important natural process is the alternation of wetting and drying (W–D) processes, which induce swelling and shrinking of soil particles, causing modifications in pore size and shape. To study the consequence of these W–D events on possible modifications in pore size distribution, pore number, and pore shape of soil samples collected in metal rings pore image analysis was used. Samples were taken from profiles of three soils of different characteristics, named as Geric Ferralsol (GF), Eutric Nitosol (EN), and Rhodic Ferralsol (RF). Confined volumetric samples (50 cm3) were submitted to none (T0), three (T1), and nine (T2) subsequent W–D cycles. Image cross sections of resin impregnated soil permitted the micrometric and macrometric characterization of changes in soil structure induced by sequences of W–D cycles. Duncan's statistical test indicated that there were significant differences (α = 0.05) among treatments for all soil samples. General conclusions indicate that total pore area increased for all soils after repeated W–D processes, specifically 19.0 to 28.9% for GF, 5.9 to 11.7% for EN, and 13.0 to 17.2% for RF. Main changes of pore diameter occurred in pores larger than 500 μm, and minor changes were observed in the total number of these pores. It is demonstrated that soil samples undergo important changes in their structures after repeated W–D cycles. The information presented here is very important for the evaluation of soil water retention curves and other soil hydric properties, because soil samples used in these procedures are collected in rings and frequently submitted to several W–D cycles. 相似文献
15.
基于低场核磁技术研究土壤持水性能与孔隙特征 总被引：3，自引：0，他引：3
为研究常规水稻土和设施蔬菜地土壤持水性能与孔隙分布特征,利用低场核磁共振技术,获取田间持水量状态的土壤T_2谱线特征,在此基础上分析了土壤失水时信号幅值、弛豫时间与土壤含水量和孔隙大小分布的关系。结果表明:水稻土和设施蔬菜地土壤中孔隙分布均比较分散,小孔隙居多,大孔隙较少,水稻田转化为设施蔬菜地后,土壤孔隙半径整体变小,土壤结构恶化。在土壤失水过程中,波峰消减与谱线偏移同时发生,小峰优先消失且消减速率大于主峰,表明该过程中孔隙收缩与水分散失同时发生,土壤孔隙由大到小依次不断排水。低场核磁共振作为一种快速、无损的测量工具,能够更直接、更准确地反映出土壤水分迁移过程和孔隙分布规律,从而为设施栽培土壤退化机理和土壤改良提供新的理论和技术支撑。 相似文献
16.
基于CT分析露天煤矿复垦年限对土壤有效孔隙数量和孔隙度的影响 总被引：11，自引：7，他引：4
露天煤矿排土场由于排土过程中大型机械压实等作用会对土壤的孔隙结构产生影响,重构适合于植被生长的土壤孔隙结构是排土场土地复垦的重要工作。为对排土场重构土壤孔隙结构进行定量分析,该文采用高精度无损计算机断层扫描技术(CT)对山西平朔矿区安太堡露天煤矿排土场平台全黄土母质覆盖的不同复垦年限(0、20、23 a)以及原地貌的土壤进行分层扫描成像,并利用Photoshop和Arcgis软件对扫描图像进行处理和统计分析,探讨了排土和复垦对土壤孔隙数量和孔隙度的影响,分析了排土场重构土壤大、中和小孔隙的变化。结果表明:原地貌土壤孔隙数量和孔隙度最大,其次是复垦23和20 a的土壤,排土后未复垦土壤孔隙数量和孔隙度最小。采矿和排土等活动由于大型机械压实作用降低了土壤孔隙数量和孔隙度,尤其是大孔隙数量和大孔隙度;土地复垦对增加土壤孔隙数量和孔隙度有一定的作用,但是过程比较缓慢。采矿和排土等活动对表层土壤孔隙数量和孔隙度的影响要高于底层土壤。该研究可为黄土区大型露天煤矿排土场重构土壤结构的优化与土地复垦措施选择提供依据。 相似文献
17.
Soil physical properties related to soil structure 总被引：3，自引：0，他引：3
The aim of this paper is to clarify the effect of soil aggregation on soil physical and chemical properties of structured soils both on a bulk soil scale, for single aggregates, as well as for homogenized material. Aggregate formation and aggregate strength depend on swelling and shrinkage processes and on biological activity and kinds of organic exudates as well as on the intensity, number and time of swelling and drying events. Such aggregates are, most of all, more dense than the aggregated bulk soil. The intra-aggregate pore distribution consists not only of finer pores but these are also more tortuous. Thus, water fluxes in aggregated soils are mostly multidimensional and the corresponding water fluxes in the intra-aggregate pore system are much smaller. Furthermore, ion transport by mass flow as well as by diffusion are delayed, whereby the length of the flow path in such tortuous finer pores further retards chemical exchange processes. The chemical composition of the percolating soil solution differs even more from that of the corresponding homogenized material the stronger and denser the aggregates are.
The rearrangement of particles by aggregate formation also induces an increased apparent thermal diffusivity as compared with the homogenized material. The aggregate formation also affects the aeration and the gaseous composition of the intra-aggregate pore space. Depending on the kind and intensity of aggregation, the intra-aggregate pores can be completely anoxic, while the inter-aggregate pores are already completely aerated. The higher the amount of dissolved organic carbon in the percolating soil solution, the more pronounced is the difference between the gaseous composition in the inter- and in the intra-aggregate pore system.
From the mechanical point of view, the strength single aggregates, determined as the angle of internal friction and cohesion, depends on the number of contact points or the forces, which can be transmitted at each single contact point. The more structured soils are, the higher the proportion of the effective stress on the total stress is, but even in single aggregates positive pore water pressure values can be revealed. Dynamic forces e.g. due to wheeling and/or slip processes can affect the pore system as well as the composition of the soil by: (1) a rearrangement of single aggregates in the existing inter-aggregate pore system resulting in an increased bulk density and a less aerated and less rootable soil volume, (2) a complete homogenization, i.e. aggregate deterioration due to shearing. Thus, the smaller texture dependent soil strength coincides with a more intensive soil compaction due to loading. (3) Aggregate deterioration due to shearing results in a complete homogenization, if excess soil water is available owing to kneading as soon as the octahedral shear stresses and the mean normal stresses exceed the stress state defined by the Mohr-Coulomb failure line. Consequently, normal shrinkage processes start again.
Thus, the rearrangement of particles and the formation of well defined single aggregates even at the same bulk density of the bulk soil both affect, to a great extent, various ecological parameters. Environmental aspects can also be correlated, or at least explained with the processes in soils, as a major compartment of terrestial ecosystems, if the physical and chemical properties of the structure elements and their composition in the bulk soil are understood. 相似文献
18.
Oxygen is a prerequisite for some and an inhibitor to other microbial functions in soils, hence the temporal and spatial distribution of oxygen within the soil matrix is crucial in soil biogeochemistry and soil biology. Various attempts have been made to model the anaerobic fraction of the soil volume as a function of structure, moisture content and oxygen consumption. Aggregate models are attractive but difficult to parameterize and not applicable to non-aggregated soils. Pore models are preferable for pragmatic reasons, but the existing versions appear to overestimate the anaerobic volume at intermediate soil moisture contents. A modified pore model is proposed, in which anaerobiosis is calculated from a range of air filled pore size classes, based on the soil water retention curve and the soil moisture content. In comparison with previous pore models which are based on the estimation of an average size of the air filled pores, the pore class model presented here appears to give more adequate estimates of anaerobic volumes, especially at intermediate moisture contents. The pore model is attractive for process modelling of anaerobic functions such as denitrification, since it can easily be parameterized by the water retention characteristics of a soil. 相似文献
19.
Morphological determination of pore connectivity as a function of pore size using serial sections 总被引：9，自引：0，他引：9
H. J. VOGEL 《European Journal of Soil Science》1997,48(3):365-377
The geometry of pore space in soil is considered to be the key in understanding transport of water, gas and solute. However, a quantitative and explicit characterization, by means of a physical interpretation, is difficult because of the geometric complexity of soil structure. Pores larger than 40 μm within two soil horizons have been analysed morphologically on 3-dimensional digital representations of the pore space obtained by serial sections through impregnated specimens. The Euler-Poincaré characteristic has been determined as an index of connectivity in three dimensions. The pore connectivity is quantified as a function of the minimum pore diameter considered leading to a connectivity function of the pore space. Different pore size classes were distinguished using 3-dimensional erosion and dilation. The connectivity function turned out to differentiate between two soil materials. The pore space in an upper Ah horizon is intensely connected through pores between 40 and 100 μm, in contrast to the pore space in the AhBv beneath it. The morphological pore-size distributions were compared to the pore-size distribution obtained by water retention measurements. The discrepancy between these different methods corresponds to the expectation due to pore connectivity. 相似文献