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Enhancing Surface Soil Moisture Estimation through Integration of Artificial Neural Networks Machine Learning and Fusion of Meteorological, Sentinel-1A and Sentinel-2A Satellite Data
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作者 Jephter Ondieki Giovanni Laneve +1 位作者 Maria Marsella Collins Mito 《Advances in Remote Sensing》 2023年第4期99-122,共24页
For many environmental and agricultural applications, an accurate estimation of surface soil moisture is essential. This study sought to determine whether combining Sentinel-1A, Sentinel-2A, and meteorological data wi... For many environmental and agricultural applications, an accurate estimation of surface soil moisture is essential. This study sought to determine whether combining Sentinel-1A, Sentinel-2A, and meteorological data with artificial neural networks (ANN) could improve soil moisture estimation in various land cover types. To train and evaluate the model’s performance, we used field data (provided by La Tuscia University) on the study area collected during time periods between October 2022, and December 2022. Surface soil moisture was measured at 29 locations. The performance of the model was trained, validated, and tested using input features in a 60:10:30 ratio, using the feed-forward ANN model. It was found that the ANN model exhibited high precision in predicting soil moisture. The model achieved a coefficient of determination (R<sup>2</sup>) of 0.71 and correlation coefficient (R) of 0.84. Furthermore, the incorporation of Random Forest (RF) algorithms for soil moisture prediction resulted in an improved R<sup>2</sup> of 0.89. The unique combination of active microwave, meteorological data and multispectral data provides an opportunity to exploit the complementary nature of the datasets. Through preprocessing, fusion, and ANN modeling, this research contributes to advancing soil moisture estimation techniques and providing valuable insights for water resource management and agricultural planning in the study area. 展开更多
关键词 soil Moisture Estimation Techniques Fusion Active Microwave Multispectral data Agricultural Planning
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Identifying Pathfinder Elements for Gold in Multi-Element Soil Geochemical Data from the Wa-Lawra Belt, Northwest Ghana: A Multivariate Statistical Approach 被引量:2
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作者 Prosper Mackenzie Nude John Mahfouz Asigri +3 位作者 Sandow Mark Yidana Emmanuel Arhin Gordon Foli Jacob Mawuko Kutu 《International Journal of Geosciences》 2012年第1期62-70,共9页
A multivariate statistical analysis was performed on multi-element soil geochemical data from the Koda Hill-Bulenga gold prospects in the Wa-Lawra gold belt, northwest Ghana. The objectives of the study were to define... A multivariate statistical analysis was performed on multi-element soil geochemical data from the Koda Hill-Bulenga gold prospects in the Wa-Lawra gold belt, northwest Ghana. The objectives of the study were to define gold relationships with other trace elements to determine possible pathfinder elements for gold from the soil geochemical data. The study focused on seven elements, namely, Au, Fe, Pb, Mn, Ag, As and Cu. Factor analysis and hierarchical cluster analysis were performed on the analyzed samples. Factor analysis explained 79.093% of the total variance of the data through three factors. This had the gold factor being factor 3, having associations of copper, iron, lead and manganese and accounting for 20.903% of the total variance. From hierarchical clustering, gold was also observed to be clustering with lead, copper, arsenic and silver. There was further indication that, gold concentrations were lower than that of its associations. It can be inferred from the results that, the occurrence of gold and its associated elements can be linked to both primary dispersion from underlying rocks and secondary processes such as lateritization. This data shows that Fe and Mn strongly associated with gold, and alongside Pb, Ag, As and Cu, these elements can be used as pathfinders for gold in the area, with ferruginous zones as targets. 展开更多
关键词 MULTIVARIATE Analyses Multi-Elements soil Geochemical data PATHFINDER ELEMENTS GOLD NORTHWEST Ghana
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Analysis of influence of observation operator on sequential data assimilation through soil temperature simulation with common land model 被引量:2
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作者 Xiao-lei Fu Zhong-bo Yu +4 位作者 Yong-jian Ding Ying Tang Hai-shen Lü Xiao-lei Jiang Qin Ju 《Water Science and Engineering》 EI CAS CSCD 2018年第3期196-204,共9页
An observation operator is a bridge linking the system state vector and observations in a data assimilation system. Despite its importance, the degree to which an observation operator influences the performance of dat... An observation operator is a bridge linking the system state vector and observations in a data assimilation system. Despite its importance, the degree to which an observation operator influences the performance of data assimilation methods is still poorly understood. This study aimed to analyze the influences of linear and nonlinear observation operators on the sequential data assimilation through soil temperature simulation using the unscented particle filter(UPF) and the common land model. The linear observation operator between unprocessed simulations and observations was first established. To improve the correlation between simulations and observations, both were processed based on a series of equations. This processing essentially resulted in a nonlinear observation operator. The linear and nonlinear observation operators were then used along with the UPF in three assimilation experiments: an hourly in situ soil surface temperature assimilation, a daily in situ soil surface temperature assimilation, and a moderate resolution imaging spectroradiometer(MODIS) land surface temperature(LST) assimilation. The results show that the filter improved the soil temperature simulation significantly with the linear and nonlinear observation operators. The nonlinear observation operator improved the UPF's performance more significantly for the hourly and daily in situ observation assimilations than the linear observation operator did, while the situation was opposite for the MODIS LST assimilation. Because of the high assimilation frequency and data quality, the simulation accuracy was significantly improved in all soil layers for hourly in situ soil surface temperature assimilation, while the significant improvements of the simulation accuracy were limited to the lower soil layers for the assimilation experiments with low assimilation frequency or low data quality. 展开更多
关键词 OBSERVATION OPERATOR Unscented PARTICLE filter(UPF) soil temperature MODIS LST data ASSIMILATION
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Interrelationship Analysis of L-Band Backscattering Intensity and Soil Dielectric Constant for Soil Moisture Retrieval Using PALSAR Data 被引量:1
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作者 Saeid Gharechelou Ryutaro Tateishi Josaphat Tetuko Sri Sumantyo 《Advances in Remote Sensing》 2015年第1期15-24,共10页
The purpose of this paper is to study about the interrelationship between the backscattering intensity of PALSAR data and the laboratory measurement of dielectric constant and soil moisture. The characterization of th... The purpose of this paper is to study about the interrelationship between the backscattering intensity of PALSAR data and the laboratory measurement of dielectric constant and soil moisture. The characterization of the dielectric constant of arid soils in the 0.3 - 3 GHz frequency range, particularly focused in L-band was analyzed in varied soil moisture content and soil textures. The interrelationship between the relative dielectric constant with soil textures and backscattering of PALSAR data was also analyzed and statistical model was computed. In this study, after collecting the soil samples in the field from top soil (0 - 10 cm) in a homogeneous area then, the dielectric constant was measured using a dielectric probe tool kit. For investigated of the characteristics and behaviors of the dielectric constant and relationship with backscattering a variety of moisture content from 0% to 40% and soil fraction conditions was tested in laboratory condition. All data were analyzed by integrating it with other geophysical data in GIS, such as land cover and soil texture. Thus, the regression model computed between measured soil moisture and backscattering coefficient of PALSR data which were extracted as same point of each soil sample pixel. Finally, after completing the preprocessing, such as removing the speckle noise by averaging, the model was applied to the PALSAR data for retrieving the soil moisture map in arid region of Iran. The analysis of dielectric constant properties result has shown the soil texture after the moisture content has the largest effected on dielectric constant. In addition, the PALSAR data in dual polarization are also able to derive the soil moisture using statistical method. The dielectric constant and backscattering shown have the exponential relationship and the HV polarization mode is more sensitive than the HH mode to soil moisture and overestimated the soil moisture as well. The validation of result has shown the 4.2 Vol-% RMSE of soil moisture. It means that the backscattering analysis should consider about other factors such a surface roughness and mix pixel of vegetation effective. 展开更多
关键词 SAR Dielectric Constant soil Moisture ARID soil BACKSCATTERING soil Texture PALSAR data
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Monitoring Soil Salt Content Using HJ-1A Hyperspectral Data: A Case Study of Coastal Areas in Rudong County, Eastern China 被引量:5
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作者 LI Jianguo PU Lijie +5 位作者 ZHU Ming DAI Xiaoqing XU Yan CHEN Xinjian ZHANG Lifang ZHANG Runsen 《Chinese Geographical Science》 SCIE CSCD 2015年第2期213-223,共11页
Hyperspectral data are an important source for monitoring soil salt content on a large scale. However, in previous studies, barriers such as interference due to the presence of vegetation restricted the precision of m... Hyperspectral data are an important source for monitoring soil salt content on a large scale. However, in previous studies, barriers such as interference due to the presence of vegetation restricted the precision of mapping soil salt content. This study tested a new method for predicting soil salt content with improved precision by using Chinese hyperspectral data, Huan Jing-Hyper Spectral Imager(HJ-HSI), in the coastal area of Rudong County, Eastern China. The vegetation-covered area and coastal bare flat area were distinguished by using the normalized differential vegetation index at the band length of 705 nm(NDVI705). The soil salt content of each area was predicted by various algorithms. A Normal Soil Salt Content Response Index(NSSRI) was constructed from continuum-removed reflectance(CR-reflectance) at wavelengths of 908.95 nm and 687.41 nm to predict the soil salt content in the coastal bare flat area(NDVI705 < 0.2). The soil adjusted salinity index(SAVI) was applied to predict the soil salt content in the vegetation-covered area(NDVI705 ≥ 0.2). The results demonstrate that 1) the new method significantly improves the accuracy of soil salt content mapping(R2 = 0.6396, RMSE = 0.3591), and 2) HJ-HSI data can be used to map soil salt content precisely and are suitable for monitoring soil salt content on a large scale. 展开更多
关键词 soil salt content normalized differential vegetation index(NDVI) hyperspectral data Huan Jing-Hyper Spectral Imager(HJ-HSI) coastal area eastern China
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A STUDY OF SOIL CONSERVATION MONITORING INFORMATION SYSTEM BASED ON REMOTELY SENSED DATA FOR A CATCHMENT ON THE LOESS PLATEAU
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作者 Li Rui, Li Bichen, Ma Xiaoyun (Northwesterng Institute of Soil and Water Conservation, Academia Sinica and Ministry of Water Resources) 《遥感信息》 CSCD 1990年第A02期41-42,共2页
The Soil Conservation Monitorins Information System (SCMIS) presented in this paper is oriented to soil erosion control, resources exploitation, utilization, planning and management for a small watershed (about 10 sq.... The Soil Conservation Monitorins Information System (SCMIS) presented in this paper is oriented to soil erosion control, resources exploitation, utilization, planning and management for a small watershed (about 10 sq. km.) on the Loess Plateau. It sums up Remote sensing (RS), Geographical Information System (GIS) and Expert System (ES) and consists of a integrated system. As a basic level information system of Loess Plateau, its perfection and psreading will bring about a great advance in resources exploitation and management of Loess Plateau. 展开更多
关键词 SCMIS A STUDY OF soil CONSERVATION MONITORING INFORMATION SYSTEM BASED ON REMOTELY SENSED data FOR A CATCHMENT ON THE LOESS PLATEAU GIS data
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Data assimilation using support vector machines and ensemble Kalman filter for multi-layer soil moisture prediction 被引量:1
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作者 Di LIU Zhong-bo YU Hai-shen LV 《Water Science and Engineering》 EI CAS 2010年第4期361-377,共17页
Hybrid data assimilation (DA) is a method seeing more use in recent hydrology and water resources research. In this study, a DA method coupled with the support vector machines (SVMs) and the ensemble Kalman filter... Hybrid data assimilation (DA) is a method seeing more use in recent hydrology and water resources research. In this study, a DA method coupled with the support vector machines (SVMs) and the ensemble Kalman filter (EnKF) technology was used for the prediction of soil moisture in different soil layers: 0-5 cm, 30 cm, 50 cm, 100 cm, 200 cm, and 300 cm. The SVM methodology was first used to train the ground measurements of soil moisture and meteorological parameters from the Meilin study area, in East China, to construct soil moisture statistical prediction models. Subsequent observations and their statistics were used for predictions, with two approaches: the SVM predictor and the SVM-EnKF model made by coupling the SVM model with the EnKF technique using the DA method. Validation results showed that the proposed SVM-EnKF model can improve the prediction results of soil moisture in different layers, from the surface to the root zone. 展开更多
关键词 data assimilation support vector machines ensemble Kalman filter soil moisture
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北京山区不同植被恢复类型土壤质量综合评价 被引量:2
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作者 李鹏 齐实 +8 位作者 张林 胡俊 唐颖 逯进生 王翔宇 赖金林 廖瑞恩 张岱 张岩 《水土保持学报》 CSCD 北大核心 2024年第1期337-346,356,共11页
[目的]综合评价北京山区不同植被恢复类型土壤质量,并进一步确定影响土壤质量的关键因素,为该地区植被恢复与重建提供数据支撑。[方法]以立地条件相近的侧柏纯林、油松纯林、侧柏油松混交林、侧柏针阔混交林、油松针阔混交林、落叶阔叶... [目的]综合评价北京山区不同植被恢复类型土壤质量,并进一步确定影响土壤质量的关键因素,为该地区植被恢复与重建提供数据支撑。[方法]以立地条件相近的侧柏纯林、油松纯林、侧柏油松混交林、侧柏针阔混交林、油松针阔混交林、落叶阔叶混交林和无林地(对照)为研究对象,测定14个土壤理化指标作为土壤质量评价的总数据集(TDS),采用主成分分析法(PCA)和Pearson相关性分析建立土壤质量最小数据集(MDS),利用线性(L)和非线性(NL)2种评分方法计算土壤质量指数(SQI)和一般线性模型(GLM)确定影响土壤质量的关键因素。[结果]植被恢复后相较于无林地,土壤容重、砂粒含量下降,而有机质、全氮、全钾、速效氮、速效钾等土壤养分含量增加。筛选出的研究区土壤质量评价MDS指标为全氮、砂粒、全钾、pH、有效含水量。4种方法(SQI-LT、SQI-NLT、SQI-LM、SQI-NLM)下,不同植被恢复类型的SQI值排序均为落叶阔叶混交林>侧柏针阔混交林>油松纯林>油松针阔混交林>侧柏油松混交林>侧柏纯林>无林地,植被恢复后土壤质量显著提升。SQI-NLM的土壤质量评价方法在北京山区具有更好的适用性。相较于无林地,其他植被恢复类型的SQI-NLM分别提高64%,48%,45%,36%,33%,27%。GLM模型解释了土壤质量指数总变异的85.24%,植被类型对土壤质量指数的解释比例最大(45.09%)。[结论]选择适宜的植被恢复类型是改善区域土壤质量的关键。未来实施植被恢复时,树种选择上优先考虑阔叶树种。造林配置方式的选择应取决于树种而定,如侧柏纯林中引入本土阔叶树种形成侧柏针阔混交林或选择油松纯林是最佳造林模式。 展开更多
关键词 植被恢复 土壤质量指数(SQI) 最小数据集(MDS) GLM 北京山区
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辐射计辅助的地基GNSS-R土壤湿度反演方法研究
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作者 郭秀梅 逄海港 孙波 《山东农业大学学报(自然科学版)》 北大核心 2024年第3期396-405,共10页
基于全球导航卫星系统反射信号(Global Navigation Satellite System-Reflection,GNSS-R)的土壤湿度监测弥补了传统测量方法的不足,是近年来遥感领域研究的热点。针对土壤粗糙度及植被含水量影响反演精度的问题,研究了利用辐射计数据辅... 基于全球导航卫星系统反射信号(Global Navigation Satellite System-Reflection,GNSS-R)的土壤湿度监测弥补了传统测量方法的不足,是近年来遥感领域研究的热点。针对土壤粗糙度及植被含水量影响反演精度的问题,研究了利用辐射计数据辅助提升精度的方法。提出了一种基于非线性自回归模型的神经网络(NARX)的GNSS-R和辐射计数据融合的土壤湿度反演模型,通过信号处理的一般流程,进行现场实验,验证了该方法。结果表明,在测试集上所提出的反演方法相比于传统的GNSS-R方法,相关系数提高了77%,均方根误差下降了78%,与辐射计方法相比,相关系数提高了47%,均方根误差下降了68%,证明了该方法可以实现对固定区域土壤湿度的长期连续观测。 展开更多
关键词 GNSS-R 土壤湿度 NARX 辐射计 数据融合
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便携式XRF对西南喀斯特地区碳酸盐岩风化壳土壤分析适用性评估 被引量:1
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作者 徐少强 杨菲 +2 位作者 刘爽 罗维均 彭韬 《地球与环境》 CAS CSCD 北大核心 2024年第1期1-10,共10页
应用便携式X射线荧光光谱仪(pXRF)分析了西南喀斯特地区碳酸盐岩风化壳土壤,并与实验室(LAB)分析结果对比,判定了20种元素分析结果的质量等级,探究了检测时长和粒径对精密度的影响,在pXRF中构建了碳酸盐岩风化壳土壤模式,评估了pXRF对... 应用便携式X射线荧光光谱仪(pXRF)分析了西南喀斯特地区碳酸盐岩风化壳土壤,并与实验室(LAB)分析结果对比,判定了20种元素分析结果的质量等级,探究了检测时长和粒径对精密度的影响,在pXRF中构建了碳酸盐岩风化壳土壤模式,评估了pXRF对该类土壤分析的适用性。主要结果为:1)整体上,pXRF对碳酸盐岩风化壳土壤有较好的分析能力;2)检测时长为120 s时能够兼顾精密度与检测效率;3)粒径从10目减小到200目时,Cu、Nb、Ba、Ce和Th的数据质量等级得到提高,其余15种元素不受影响;4)碳酸盐岩风化壳土壤模式显著提高了pXRF对同类土壤的分析能力,但对碎屑岩和玄武岩的风化壳土壤适用性低。西南喀斯特地区土壤类型丰富,异质性大,单一检测模式难以满足多样化的分析工作,亟需针对特定类型土壤构建检测模式,提高分析精确度,充分发挥pXRF的优越性能,助力西南喀斯特地区土壤地球化学分析工作。同时,本文还为优化pXRF分析能力提供了一种新思路。 展开更多
关键词 PXRF 碳酸盐岩风化壳土壤 质量等级 土壤模式
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基于CDF匹配校正的珠江流域多源微波土壤水分产品融合
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作者 何全军 张月维 +1 位作者 石艳军 胡鑫 《中国农业气象》 CSCD 2024年第11期1276-1289,共14页
单颗卫星反演的土壤水分产品存在时空覆盖不连续的问题。为获得珠江流域时空连续的卫星遥感土壤水分数据,以SMAP卫星的体积土壤水分(VSM)产品为参考,基于累积分布函数(CDF)法匹配校正AMSR2、SMOS和MWRI卫星的遥感反演VSM产品,采用最优... 单颗卫星反演的土壤水分产品存在时空覆盖不连续的问题。为获得珠江流域时空连续的卫星遥感土壤水分数据,以SMAP卫星的体积土壤水分(VSM)产品为参考,基于累积分布函数(CDF)法匹配校正AMSR2、SMOS和MWRI卫星的遥感反演VSM产品,采用最优插值法融合上述4种VSM产品,生成珠江流域时空连续的10km分辨率逐日VSM融合产品,利用地面站观测数据以及再分析数据对VSM融合产品进行检验。结果表明:(1)4种卫星反演的土壤水分产品有明显测量范围差异,测量范围从高到低依次是SMOS、AMSR2、SMAP和MWRI,最大测量值分别为1.00、0.99、0.70以及0.50m^(3)·m^(-3),不适合同时用于同一地区的土壤水分监测。(2)多源卫星VSM产品间存在偏差。与SMAP的VSM产品相比,SMOS的VSM产品较其存在负偏差,二者无偏均方根误差最小且相关系数最高;AMSR2的VSM产品与其存在正偏差且相关性较低;MWRI的VSM产品与其存在负偏差且相关性最小。(3)SMAP的VSM产品精度和稳定性优于AMSR2、SMOS和MWRI的VSM产品,与观测数据和再分析数据时间序列相关性显著优于后3者。(4)经过CDF匹配偏差校正,增强了AMSR2、SMOS和MWRI的VSM产品与SMAP的VSM产品间一致性。多源数据融合可修正单颗卫星产品的误差,提高与观测数据和再分析数据间的相关性,弥补遥感观测数据的时空连续性。 展开更多
关键词 珠江流域 微波遥感 土壤水分 偏差校正 数据融合
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基于最小数据集的集约化葡萄园土壤健康评价 被引量:2
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作者 王斌 李云 +3 位作者 李瑞鹏 方菲 张江周 张俊伶 《农业工程学报》 EI CAS CSCD 北大核心 2024年第8期71-79,共9页
健康土壤是生产高产优质葡萄的基础,目前葡萄园不合理管理导致果园土壤生产力下降和生态失衡。为摸清集约化葡萄园土壤健康状况,该研究以河北省曲周县典型葡萄园为研究对象,通过测定20项土壤物理、化学和生物学指标,利用主成分分析法构... 健康土壤是生产高产优质葡萄的基础,目前葡萄园不合理管理导致果园土壤生产力下降和生态失衡。为摸清集约化葡萄园土壤健康状况,该研究以河北省曲周县典型葡萄园为研究对象,通过测定20项土壤物理、化学和生物学指标,利用主成分分析法构建最小数据集,开展土壤健康评价并揭示葡萄园存在的主要障碍因子。结果表明,集约化葡萄园土壤健康评价最小数据集由有机碳、亚表层土壤硬度、交换性钠、容重、含水率和水稳性团聚体6个指标构成。利用线性和非线性评分函数,基于全数据集和最小数据集计算的土壤健康指数间呈显著正相关(P<0.01),这说明最小数据集可以代替全数据集用于葡萄园土壤健康评价。基于最小数据集,利用线性和非线性评分函数获得的葡萄园土壤健康指数范围分别为0.39~0.59和0.36~0.66,平均值分别为0.52和0.51,处于中等水平。不同树龄葡萄土壤健康指数差异不显著(P>0.05)。集约化葡萄园土壤障碍因子主要有土壤压实、养分不平衡和有机碳含量低等问题。通过适当减少田间管理频率,结合增施(生物)有机肥、种植覆盖作物和养分综合管理能有效消减土壤障碍因子,提升葡萄园土壤健康水平,促进当地葡萄产业可持续发展。 展开更多
关键词 土壤 葡萄园 主成分分析 最小数据集 土壤健康指数
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深挖方膨胀土边坡时空变形特征分析
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作者 胡江 李星 《岩土力学》 EI CAS CSCD 北大核心 2024年第10期3071-3080,共10页
深挖方膨胀土边坡受降水、地下水以及地质构造、支护措施等多因素影响,变形呈现复杂的时空异质性。以南水北调中线总干渠陶岔渠首段边坡为例,开展时空变形特征分析。借助变分模态分解、加权多尺度局部异常系数以及聚类分析等数据挖掘方... 深挖方膨胀土边坡受降水、地下水以及地质构造、支护措施等多因素影响,变形呈现复杂的时空异质性。以南水北调中线总干渠陶岔渠首段边坡为例,开展时空变形特征分析。借助变分模态分解、加权多尺度局部异常系数以及聚类分析等数据挖掘方法,分析变形的时间变化规律,识别空间分布特征;阐释降水量、地下水位等因素对边坡变形趋势性、周期性和波动性分量的影响机制;对边坡变形进行分区分析,推测潜在滑动面和滑动体;讨论边坡变形机制。结果表明,边坡变形呈现显著的趋势性变化,还表现出季节性和间歇性。下部变形值较大,往上逐渐减少。上部显著变形区深度为3 m,位于大气影响层内;中部受地下水波动和裂隙密集带影响,显著变形区较深,达11m;下部受支护体系限制,变形主要位于浅层。上层滞水受雨水补给,波动范围大,导致中上部变形深度较深,在16.5m深度内仍存在一定变形。潜在滑动面为折线形,前缘受地下水、裂隙密集带和边坡支护体系影响,近似水平。为减少地下水波动对膨胀土胀缩变形的影响,建议采用排水井降排深层地下水。该研究成果可为深挖方膨胀土边坡运行管理和加固处置提供技术支撑。 展开更多
关键词 膨胀土 边坡 变形 滑动面 地下水 数据挖掘
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基于聚类及PCA分析的羌活栽培区土壤质量评价
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作者 王红兰 蒋舜媛 +4 位作者 崔俊芳 杜玖珍 杨萍 周毅 朱文涛 《安徽农业大学学报》 CAS CSCD 2024年第5期857-864,共8页
为了准确评价川产道地药材羌活栽培区耕作层土壤质量状况,分别采用聚类分析法(CA)和主成分分析法(PCA)构建栽培区耕作层土壤质量最小数据集(minimum data set,MDS),利用最小数据集土壤质量指数(soil quality index-CA,SQI-CA和SQI-PCA)... 为了准确评价川产道地药材羌活栽培区耕作层土壤质量状况,分别采用聚类分析法(CA)和主成分分析法(PCA)构建栽培区耕作层土壤质量最小数据集(minimum data set,MDS),利用最小数据集土壤质量指数(soil quality index-CA,SQI-CA和SQI-PCA)和全量数据集土壤质量指数(SQI-T)评价川西北羌活栽培区耕作层土壤质量。结果表明:(1)羌活栽培区土壤有机质含量为(19.14±6.75)g·kg^(−1),处于中度贫瘠化水平;土壤速效氮、速效磷和速效钾含量较高,分别为(129.78±47.78)mg·kg^(−1)、(22.89±14.78)g·kg^(−1)和(159.87±97.87)mg·kg^(−1);土壤为中性土壤,pH均值为7.20±1.68。(2)基于不同数据集的土壤质量指数均值排序为SQI-T>SQI-PCA>SQI-CA,而SQI-PCA与SQI-T之间的Nash有效系数高于SQI-CA,相对偏差系数低于SQI-CA,说明基于主成分分析的最小数据集(MDS-PCA)评价效果更优,该数据集包括土壤容重、抗剪强度、有机质含量、饱和导水率、黏粒含量、pH、速效氮和砂粒含量共8个指标。(3)川西北羌活栽培区土壤质量指数SQI-PCA<0.33,表明该研究区耕作层土壤质量总体水平较差,主要体现在土壤紧实、有机质含量低,需要通过合理耕作、施肥和土壤改良等方式对耕作层土壤质量进行有效调控。研究结果可为川西北高原羌活栽培区土壤质量改良和生产适宜性调控提供参考,有利于川西北高原区中药材产区土壤可持续利用。 展开更多
关键词 羌活 土壤质量 聚类分析 主成分分析 最小数据集
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多源土壤湿度产品在云南省的适用性评估 被引量:1
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作者 杨祥磊 吕爱锋 张文翔 《南水北调与水利科技(中英文)》 CAS CSCD 北大核心 2024年第4期759-773,共15页
为了解不同土壤湿度产品在云南省的适用性和可靠性,基于云南省的94个站点数据以及TC(triplecollocation)方法评估5种不同土壤湿度数据在云南省的适用性及不同干湿条件下的表现,包括ERA5-Land(the fifth global atmospheric analysis dat... 为了解不同土壤湿度产品在云南省的适用性和可靠性,基于云南省的94个站点数据以及TC(triplecollocation)方法评估5种不同土壤湿度数据在云南省的适用性及不同干湿条件下的表现,包括ERA5-Land(the fifth global atmospheric analysis dataset for the land component of the European Centre for Medium-Range Weather Forecasts(ECMWF))、GLDAS(Global Land Data Assimilation System)、SMAP(Soil Moisture Active and Passive)、MERRA-2(Modern-Era Retrospective Analysis for Research and Applications,Version 2)和ESA CCI(European Space Agency Climate Change Initiative)。结果表明:与站点数据相比,5个产品的偏差均为正偏差(0.090~0.122),明显高估了云南省的土壤湿度,但变化趋势与幅度一致,都能捕获到土壤湿度的时间变化。基于站点数据的评估结果显示:在年尺度上,ERA5-Land和SMAP与站点数据吻合程度最高,相关系数(R)分别为0.456和0.454,其次是ESA CCI(0.439);干湿季的评估结果显示,所有产品相关性均低于年尺度,且湿季高于干季,但湿季表现出更大的正偏差,其中SMAP在干季(0.323)和湿季(0.418)均表现最优。基于TC方法的评估结果显示:ERA5-Land(0.925)和ESA CCI(0.931)相关性最高;其次是GLDAS(0.890)和MERRA-2(0.864);干湿季的评估结果与站点数据的评估一致,相较于年尺度大部分产品的相关性也呈下降趋势,且干季降幅更大;SMAP干湿季R分别为0.828和0.770,表现最差;MERRA-2湿季的R(0.912)和ESD(error standard deviation)(0.020)优于其年尺度评估结果。综合来看,ESA CCI相关性较高且精度最好,更适用于云南省表层土壤湿度的监测。 展开更多
关键词 土壤湿度 站点数据 triple-collocation 干湿季节 适用性评估
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基于监测数据的广州软土基坑深层水平位移分析
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作者 黄伟豪 《四川建材》 2024年第3期69-71,74,共4页
软土基坑工程开挖会引起土体应力的重新分布,表现为地层的移动、地面沉降、围护结构变形等。以广东省广州市南沙区软黏土基坑为例,通过监测分析预应力管桩、灌注桩加1~2道扩大头预应力锚索支护形式的基坑水平变形特征,研究结果表明:软... 软土基坑工程开挖会引起土体应力的重新分布,表现为地层的移动、地面沉降、围护结构变形等。以广东省广州市南沙区软黏土基坑为例,通过监测分析预应力管桩、灌注桩加1~2道扩大头预应力锚索支护形式的基坑水平变形特征,研究结果表明:软黏土地区地基中采用联合支护形式,土体变形主要发生在开挖面以上,沿围护桩深度呈中间大、两端小分布,最大水平位移靠近基坑开挖底。基坑开挖影响范围约为2.5倍基坑开挖深度,在2.5倍开挖深度以下,土体水平位移可忽略不计,开挖对深部土层的影响较小。实际上,基坑开挖是一个复杂的动态系统,深层土体位移随开挖过程不断变化。在施工过程中应加强监测,确保周围建筑物的安全。 展开更多
关键词 软土 基坑 深层水平位移 监测数据
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亳州菊花生长与土壤肥力的关系
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作者 王一帆 陈小琴 +6 位作者 李词周 赵百海 王弢 查玉婕 谢保光 姜超强 王火焰 《土壤》 CAS CSCD 北大核心 2024年第2期291-299,共9页
采用点对点调查取样法在安徽省亳州市菊花种植区采集了116个代表性样点的植株与土壤样品,通过主成分分析法,从19项土壤理化指标中筛选出8个指标:有机质、电导率、速效氮、有效磷、有效钙、有效硫、有效铁、有效铜,构建了最小数据集(MDS)... 采用点对点调查取样法在安徽省亳州市菊花种植区采集了116个代表性样点的植株与土壤样品,通过主成分分析法,从19项土壤理化指标中筛选出8个指标:有机质、电导率、速效氮、有效磷、有效钙、有效硫、有效铁、有效铜,构建了最小数据集(MDS),并依据MDS各指标与菊花各生长指标的相关系数确定了土壤综合肥力指数(IFI),利用MDS和IFI探讨了各土壤肥力因子与菊花生长和产量的关系。结果表明:研究区菊花种植土壤总体呈弱碱性,保肥性好,盐度较低,有机质偏低,大中量养分基本充足,但微量养分相对缺乏。土壤综合肥力适中(70.69%的样点IFI分级为中等),而微量养分是土壤综合肥力提升的主要限制因子。总体来看,IFI较高的土壤更有利于菊花生长发育和高产,菊花偏好养分供应量充足、保肥性较好的中性土壤,随施肥带来的过量的硫可能对菊花生长和产量不利。 展开更多
关键词 菊花 土壤肥力 最小数据集 生长
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基于最小数据集的黔西南州烟田土壤质量评价
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作者 刘志勇 罗富方 +5 位作者 鲁万华 朱波 李洪勋 刘章勇 陈杰 易丽霞 《河南农业科学》 北大核心 2024年第7期100-108,共9页
为明确贵州省黔西南州烤烟种植区土壤质量特征,选取51个代表性土壤样点,研究其表层(0~10 cm)和亚表层(10~20 cm)土壤的理化特征及生物学性状,同时基于主成分分析(PCA)建立最小数据集(MDS),评估不同烟草连作年限(Y1:0~10 a;Y2:10~20 a;Y3... 为明确贵州省黔西南州烤烟种植区土壤质量特征,选取51个代表性土壤样点,研究其表层(0~10 cm)和亚表层(10~20 cm)土壤的理化特征及生物学性状,同时基于主成分分析(PCA)建立最小数据集(MDS),评估不同烟草连作年限(Y1:0~10 a;Y2:10~20 a;Y3:20 a以上)对植烟土壤质量指数(SQI)的影响。主成分分析结果表明,MDS由土壤有机质、全氮、全磷、碱解氮、速效钾含量及脲酶活性6项指标构成。全数据集(TDS)的土壤质量指数(TDS-SQI,均值0.589)与MDS-SQI(均值0.581)呈显著正相关关系(R^(2)=0.993,P<0.01),表明MDS和TDS均可用于解释土壤质量特征。此外,MDS-SQI与烤烟株高、叶长均呈极显著正相关关系,说明土壤MDS-SQI越大的点位附近烤烟生长状况越好,再次表明MDS相关指标具有较好的代表性。不同土层(0~10、10~20 cm)间SQI差异不显著;Y3(20 a以上)的烟田土壤SQI低于Y2(10~20 a)和Y1(0~10 a),Y1与Y3土壤SQI值差异达显著水平(P<0.05)。综上,土壤有机质、全氮、全磷、碱解氮、速效钾含量及脲酶活性6项指标可有效评估黔西南州烟田土壤质量;烟草长期连作会造成土壤质量下降。 展开更多
关键词 植烟土壤 主成分分析 最小数据集 土壤质量指数 黔西南州
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基于最小数据集的祁连山南坡不同土地利用方式土壤质量评价
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作者 邱巡巡 曹广超 +5 位作者 赵青林 曹生奎 赵美亮 何启欣 白嘉奇 咸庆玲 《草地学报》 CAS CSCD 北大核心 2024年第9期2952-2961,共10页
为了评估高寒地区不同土地利用方式下的土壤质量状况,明确不同土地利用方式下的土壤质量的关键影响因子,在祁连山南坡采集了林地、灌丛、草地及耕地4种主要土地利用类型的土壤样品174份,通过主成分分析(Principal component analysis,P... 为了评估高寒地区不同土地利用方式下的土壤质量状况,明确不同土地利用方式下的土壤质量的关键影响因子,在祁连山南坡采集了林地、灌丛、草地及耕地4种主要土地利用类型的土壤样品174份,通过主成分分析(Principal component analysis,PCA)建立最小数据集(Minimum data set,MDS),综合评估研究区不同土地利用方式下的土壤质量。结果表明:林地、灌丛、草地和耕地土壤质量指数值分别为0.535,0.519,0.466和0.544,表现为耕地>林地>灌丛>草地,对土壤质量分级为Ⅰ~Ⅵ级,对应指数分别为≤0.3,(0.3~0.4],(0.4~0.5],(0.5~0.6],(0.6,0.7]和>0.7,草地等级为Ⅲ级,处于“中等”水平;耕地、林地和灌丛土壤质量等级为Ⅳ级,处于“中等偏上”水平。土壤质量关键指标间存在互相影响,因此,建议研究区域土地要实施分类科学管理。此外,合理开发和应用绿色高效的新型生物技术是应对影响研究区土壤质量的微生物指标的有效措施。 展开更多
关键词 最小数据集 土壤质量 祁连山南坡
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智慧化技术在城市滨海软土工程的应用前景与挑战
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作者 佀传琪 王琛 +2 位作者 梁家馨 华建 梁发云 《岩土工程学报》 EI CAS CSCD 北大核心 2024年第S02期216-220,共5页
在城市建设高质量发展阶段,滨海地区面临迫切的城市更新需求。这类地区通常环境敏感复杂,传统的软土工程数据采集与分析手段往往需借助大量的人力、物力,且难以保证大范围、高效率、不间断地执行,智慧化技术成为解决这一问题的重要手段... 在城市建设高质量发展阶段,滨海地区面临迫切的城市更新需求。这类地区通常环境敏感复杂,传统的软土工程数据采集与分析手段往往需借助大量的人力、物力,且难以保证大范围、高效率、不间断地执行,智慧化技术成为解决这一问题的重要手段。梳理了智慧化技术在数据感知、智能预测和可视化交互3方面的现状,分别对比总结了接触式、非接触式感知技术,大数据分析与参数化建模方法,数字孪生与交互式平台,及其在软土工程中的应用与挑战,为深入理解智慧化技术的内涵及应用前景提供支持,助力行业新质生产力发展。 展开更多
关键词 软土地基 智能化监测 数据采集 模型构建
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