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Enhancing Deep Learning Soil Moisture Forecasting Models by Integrating Physics-based Models 被引量:1
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作者 Lu LI Yongjiu DAI +5 位作者 Zhongwang WEI Wei SHANGGUAN Nan WEI Yonggen ZHANG Qingliang LI Xian-Xiang LI 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第7期1326-1341,共16页
Accurate soil moisture(SM)prediction is critical for understanding hydrological processes.Physics-based(PB)models exhibit large uncertainties in SM predictions arising from uncertain parameterizations and insufficient... Accurate soil moisture(SM)prediction is critical for understanding hydrological processes.Physics-based(PB)models exhibit large uncertainties in SM predictions arising from uncertain parameterizations and insufficient representation of land-surface processes.In addition to PB models,deep learning(DL)models have been widely used in SM predictions recently.However,few pure DL models have notably high success rates due to lacking physical information.Thus,we developed hybrid models to effectively integrate the outputs of PB models into DL models to improve SM predictions.To this end,we first developed a hybrid model based on the attention mechanism to take advantage of PB models at each forecast time scale(attention model).We further built an ensemble model that combined the advantages of different hybrid schemes(ensemble model).We utilized SM forecasts from the Global Forecast System to enhance the convolutional long short-term memory(ConvLSTM)model for 1–16 days of SM predictions.The performances of the proposed hybrid models were investigated and compared with two existing hybrid models.The results showed that the attention model could leverage benefits of PB models and achieved the best predictability of drought events among the different hybrid models.Moreover,the ensemble model performed best among all hybrid models at all forecast time scales and different soil conditions.It is highlighted that the ensemble model outperformed the pure DL model over 79.5%of in situ stations for 16-day predictions.These findings suggest that our proposed hybrid models can adequately exploit the benefits of PB model outputs to aid DL models in making SM predictions. 展开更多
关键词 soil moisture forecasting hybrid model deep learning ConvLSTM attention mechanism
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Time-lagged Effects of the Spring Atmospheric Heat Source over the Tibetan Plateau on Summer Precipitation in Northeast China during 1961–2020:Role of Soil Moisture 被引量:1
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作者 Yizhe HAN Dabang JIANG +2 位作者 Dong SI Yaoming MA Weiqiang MA 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第8期1527-1538,共12页
The spring atmospheric heat source(AHS)over the Tibetan Plateau(TP)has been suggested to affect the Asian summer monsoon and summer precipitation over South China.However,its influence on the summer precipitation in N... The spring atmospheric heat source(AHS)over the Tibetan Plateau(TP)has been suggested to affect the Asian summer monsoon and summer precipitation over South China.However,its influence on the summer precipitation in Northeast China(NEC)remains unknown.The connection between spring TP AHS and subsequent summer precipitation over NEC from 1961 to 2020 is analyzed in this study.Results illustrate that stronger spring TP AHS can enhance subsequent summer NEC precipitation,and higher soil moisture in the Yellow River Valley-North China region(YRVNC)acts as a bridge.During spring,the strong TP AHS could strengthen the transportation of water vapor to East China and lead to excessive rainfall in the YRVNC.Thus,soil moisture increases,which regulates local thermal conditions by decreasing local surface skin temperature and sensible heat.Owing to the memory of soil moisture,the lower spring sensible heat over the YRVNC can last until mid-summer,decrease the land–sea thermal contrast,and weaken the southerly winds over the East Asia–western Pacific region and convective activities over the South China Sea and tropical western Pacific.This modulates the East Asia–Pacific teleconnection pattern,which leads to a cyclonic anomaly and excessive summer precipitation over NEC. 展开更多
关键词 Tibetan Plateau atmospheric heat source Northeast China summer precipitation soil moisture
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Erratum to:Unraveling engineering disturbance effects on deformation in red-bed mudstone railway cuttings:incorporating crack-facilitated moisture diffusion
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作者 HUANG Kang DAI Zhangjun +3 位作者 YAN Chengzeng YAO Junkai CHI Zecheng CHEN Shanxiong 《Journal of Mountain Science》 SCIE CSCD 2024年第8期2870-2870,共1页
Erratum to:J.Mt.Sci.(2024)21(5):1663-1682 https://doi.org/10.1007/s11629-023-8561-0 During the production process,the first author’s name was wrongly written as“Rang Huang”in the metadata.The correct name for the f... Erratum to:J.Mt.Sci.(2024)21(5):1663-1682 https://doi.org/10.1007/s11629-023-8561-0 During the production process,the first author’s name was wrongly written as“Rang Huang”in the metadata.The correct name for the first author is“Kang Huang”.The first author’s name in the fulltext pdf is correct. 展开更多
关键词 moisture MUDSTONE diffusion
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Feasibility of measuring moisture content of green sand by a low frequency multiprobe detector based on dielectric characteristics 被引量:1
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作者 De-quan Shi Gui-li Gao +1 位作者 Ming Sun Ya-xin Huang 《China Foundry》 SCIE CAS CSCD 2023年第3期197-206,共10页
Green sand is a mixture of silica sand,bentonite,water and coal powder,and other additives.Moisture content is an important index to characterize the properties of green sand.Based on the dielectric characteristics of... Green sand is a mixture of silica sand,bentonite,water and coal powder,and other additives.Moisture content is an important index to characterize the properties of green sand.Based on the dielectric characteristics of green sand and transmission line theory,a method for rapidly measuring the moisture content of green sand by means of a low frequency multiprobe detector was proposed.A system was constructed,where six detectors with different arrangements and probes were designed.The experimental results showed that the voltage difference of transmission line increases with the increasing frequency before 29 MHz while decreases after 35 MHz.A voltage difference platform occurs in the range of 29-35 MHz,which is suitable for measuring the moisture content due to its insensitivity to frequency.The electric field intensity gradually decreases with the increase of the probe depth,and the intensity of central probe is always greater than that of the edge probe.When the distance of the probe away from the sand sample surface is 80 mm,the electric field intensity of the edge probe is found to be very weak.The optimal excitation frequency for measuring the moisture content of green sand is 29-33 MHz.The optimal detector is the one with one center probe and three edge probes,and their lengths are 80 mm and 60 mm,respectively.The distance between the center and edge probes is 25 mm,and the diameter of probes is 5 mm.Taking the voltage difference of transmission line,bentonite content,coal powder content and compactability as parameters of the input layer,and the moisture content as a parameter of the output layer,a three-layer BP artificial neural network model for predicting the moisture content of green sand was constructed according to the experimental results at 33 MHz.The prediction error of the model is not higher than 3.3% when the moisture content of green sand is within the range of 3wt.%-7wt.%. 展开更多
关键词 green sand dielectric property moisture content multiprobe detector BP artificial neural network model
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Magneto-Photo-Thermoelastic Excitation Rotating Semiconductor Medium Based on Moisture Diffusivity
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作者 Khaled Lotfy A.M.S.Mahdy +1 位作者 Alaa A.El-Bary E.S.Elidy 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第10期107-126,共20页
In this research,we focus on the free-surface deformation of a one-dimensional elastic semiconductor medium as a function of magnetic field and moisture diffusivity.The problem aims to analyze the interconnection betw... In this research,we focus on the free-surface deformation of a one-dimensional elastic semiconductor medium as a function of magnetic field and moisture diffusivity.The problem aims to analyze the interconnection between plasma and moisture diffusivity processes,as well as thermo-elastic waves.The study examines the photothermoelasticity transport process while considering the impact of moisture diffusivity.By employing Laplace’s transformation technique,we derive the governing equations of the photo-thermo-elastic medium.These equations include the equations for carrier density,elastic waves,moisture transport,heat conduction,and constitutive relationships.Mechanical stresses,thermal conditions,and plasma boundary conditions are used to calculate the fundamental physical parameters in the Laplace domain.By employing numerical techniques,the Laplace transform is inverted to get complete time-domain solutions for the primary physical domains under study.Referencemoisture,thermoelastic,and thermoelectric characteristics are employed in conjunction with a graphical analysis that takes into consideration the effects of applied forces on displacement,moisture concentration,carrier density,stress due to forces,and temperature distribution. 展开更多
关键词 moisture diffusivity SEMICONDUCTOR photothermoelastic ROTATION thermomechanical waves laplace transform
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Unraveling engineering disturbance effects on deformation in red-bed mudstone railway cuttings:incorporating crack-facilitated moisture diffusion
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作者 HUANG Kang DAI Zhangjun +3 位作者 YAN Chengzeng YAO Junkai CHI Zecheng CHEN Shanxiong 《Journal of Mountain Science》 SCIE CSCD 2024年第5期1663-1682,共20页
Red-bed mudstone, prevalent in southwest China, poses a formidable challenge due to its hydrophilic clay minerals, resulting in expansion, deformation, and cracking upon exposure to moisture. This study addresses upli... Red-bed mudstone, prevalent in southwest China, poses a formidable challenge due to its hydrophilic clay minerals, resulting in expansion, deformation, and cracking upon exposure to moisture. This study addresses uplift deformation disasters in high-speed railways by employing a moisture diffusion-deformation-fracture coupling model based on the finite-discrete element method(FDEM). The model integrates the influence of cracks on moisture diffusion. The investigation into various excavation depths reveals a direct correlation between depth and the formation of tensile cracks at the bottom of the railway cutting. These cracks expedite moisture migration, significantly impacting the temporal and spatial evolution of the moisture field. Additionally, crack expansion dominates hygroscopic deformation, with the lateral coordinate of the crack zone determining peak vertical displacement. Furthermore, key factors influencing deformation in railway cuttings, including the swelling factor and initial moisture content at the bottom of the cutting, are explored. The number of tensile and shear cracks increases with greater excavation depth, particularly concerning shear cracks. Higher swelling factors and initial moisture contents result in an increased total number of cracks, predominantly shear cracks. Numerical calculations provide valuable insights, offering a scientific foundation and directional guidance for the precise prevention, control, prediction, and comprehensive treatment of mudstone-related issues in high-speed railways. 展开更多
关键词 Red-bed mudstone Railway cutting FDEM moisture diffusion DEFORMATION CRACK
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Synergistic Impacts of Indian Ocean SST and Indo-China Peninsula Soil Moisture on the 2020 Record-breaking Mei-yu
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作者 Yinshuo DONG Haishan CHEN +2 位作者 Xuan DONG Wenjian HUA Wenjun ZHANG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第9期1735-1750,共16页
The Yangtze River basin(YRB)experienced a record-breaking mei-yu season in June‒July 2020.This unique long-lasting extreme event and its origin have attracted considerable attention.Previous studies have suggested tha... The Yangtze River basin(YRB)experienced a record-breaking mei-yu season in June‒July 2020.This unique long-lasting extreme event and its origin have attracted considerable attention.Previous studies have suggested that the Indian Ocean(IO)SST forcing and soil moisture anomaly over the Indochina Peninsula(ICP)were responsible for this unexpected event.However,the relative contributions of IO SST and ICP soil moisture to the 2020 mei-yu rainfall event,especially their linkage with atmospheric circulation changes,remain unclear.By using observations and numerical simulations,this study examines the synergistic impacts of IO SST and ICP soil moisture on the extreme mei-yu in 2020.Results show that the prolonged dry soil moisture led to a warmer surface over the ICP in May under strong IO SST backgrounds.The intensification of the warm condition further magnified the land thermal effects,which in turn facilitated the westward extension of the western North Pacific subtropical high(WNPSH)in June‒July.The intensified WNPSH amplified the water vapor convergence and ascending motion over the YRB,thereby contributing to the 2020 mei-yu.In contrast,the land thermal anomalies diminish during normal IO SST backgrounds due to the limited persistence of soil moisture.The roles of IO SST and ICP soil moisture are verified and quantified using the Community Earth System Model.Their synergistic impacts yield a notable 32%increase in YRB precipitation.Our findings provide evidence for the combined influences of IO SST forcing and ICP soil moisture variability on the occurrence of the 2020 super mei-yu. 展开更多
关键词 super mei-yu Indian Ocean SST soil moisture Indochina Peninsula
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Antecedent Precipitation Index to Estimate Soil Moisture and Correlate as a Triggering Process in the Occurrence of Landslides
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作者 Marcio Augusto Ernesto De Moraes Walter Manoel Mendes Filho +6 位作者 Rodolfo Moreda Mendes Cassiano Antonio Bortolozo Daniel Metodiev Marcio Roberto Magalhães De Andrade Harideva Marturano Egas Tatiana Sussel Gonçalves Mendes Luana Albertani Pampuch 《International Journal of Geosciences》 CAS 2024年第1期70-86,共17页
Landslides are highly dangerous phenomena that occur in different parts of the world and pose significant threats to human populations. Intense rainfall events are the main triggering process for landslides in urbaniz... Landslides are highly dangerous phenomena that occur in different parts of the world and pose significant threats to human populations. Intense rainfall events are the main triggering process for landslides in urbanized slope regions, especially those considered high-risk areas. Various other factors contribute to the process;thus, it is essential to analyze the causes of such incidents in all possible ways. Soil moisture plays a critical role in the Earth’s surface-atmosphere interaction systems;hence, measurements and their estimations are crucial for understanding all processes involved in the water balance, especially those related to landslides. Soil moisture can be estimated from in-situ measurements using different sensors and techniques, satellite remote sensing, hydrological modeling, and indicators to index moisture conditions. Antecedent soil moisture can significantly impact runoff for the same rainfall event in a watershed. The Antecedent Precipitation Index (API) or “retained rainfall,” along with the antecedent moisture condition from the Natural Resources Conservation Service, is generally applied to estimate runoff in watersheds where data is limited or unavailable. This work aims to explore API in estimating soil moisture and establish thresholds based on landslide occurrences. The estimated soil moisture will be compared and calibrated using measurements obtained through multisensor capacitance probes installed in a high-risk area located in the mountainous region of Campos do Jordão municipality, São Paulo, Brazil. The API used in the calculation has been modified, where the recession coefficient depends on air temperature variability as well as the climatological mean temperature, which can be considered as losses in the water balance due to evapotranspiration. Once the API is calibrated, it will be used to extrapolate to the entire watershed and consequently estimate soil moisture. By utilizing recorded mass movements and comparing them with API and soil moisture, it will be possible to determine thresholds, thus enabling anticipation of landslide occurrences. 展开更多
关键词 LANDSLIDES Antecedent Precipitation Index Soil moisture Threshold Water Balance
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Comparison of isotope-based linear and Bayesian mixing models in determining moisture recycling ratio
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作者 XIAO Yanqiong WANG Liwei +5 位作者 WANG Shengjie Kei YOSHIMURA SHI Yudong LI Xiaofei Athanassios A ARGIRIOU ZHANG Mingjun 《Journal of Arid Land》 SCIE CSCD 2024年第6期739-751,共13页
Stable water isotopes are natural tracers quantifying the contribution of moisture recycling to local precipitation,i.e.,the moisture recycling ratio,but various isotope-based models usually lead to different results,... Stable water isotopes are natural tracers quantifying the contribution of moisture recycling to local precipitation,i.e.,the moisture recycling ratio,but various isotope-based models usually lead to different results,which affects the accuracy of local moisture recycling.In this study,a total of 18 stations from four typical areas in China were selected to compare the performance of isotope-based linear and Bayesian mixing models and to determine local moisture recycling ratio.Among the three vapor sources including advection,transpiration,and surface evaporation,the advection vapor usually played a dominant role,and the contribution of surface evaporation was less than that of transpiration.When the abnormal values were ignored,the arithmetic averages of differences between isotope-based linear and the Bayesian mixing models were 0.9%for transpiration,0.2%for surface evaporation,and–1.1%for advection,respectively,and the medians were 0.5%,0.2%,and–0.8%,respectively.The importance of transpiration was slightly less for most cases when the Bayesian mixing model was applied,and the contribution of advection was relatively larger.The Bayesian mixing model was found to perform better in determining an efficient solution since linear model sometimes resulted in negative contribution ratios.Sensitivity test with two isotope scenarios indicated that the Bayesian model had a relatively low sensitivity to the changes in isotope input,and it was important to accurately estimate the isotopes in precipitation vapor.Generally,the Bayesian mixing model should be recommended instead of a linear model.The findings are useful for understanding the performance of isotope-based linear and Bayesian mixing models under various climate backgrounds. 展开更多
关键词 moisture recycling stable water isotope linear mixing model Bayesian mixing model China
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Differences in Precipitation and Related Wind Dynamics and Moisture and Heat Features in Separate Areas of the South China Sea before and after Summer Monsoon Onset
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作者 Chunyan ZHANG Donghai WANG +3 位作者 Kaifeng ZHANG Wanwen HE Yanping ZHENG Yan XU 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第8期1643-1660,共18页
Using surface and balloon-sounding measurements, satellite retrievals, and ERA5 reanalysis during 2011–20, this study compares the precipitation and related wind dynamics, moisture and heat features in different area... Using surface and balloon-sounding measurements, satellite retrievals, and ERA5 reanalysis during 2011–20, this study compares the precipitation and related wind dynamics, moisture and heat features in different areas of the South China Sea(SCS) before and after SCS summer monsoon onset(SCSSMO). The rainy sea around Dongsha(hereafter simply referred to as Dongsha) near the north coast, and the rainless sea around Xisha(hereafter simply referred to as Xisha) in the western SCS, are selected as two typical research subregions. It is found that Dongsha, rather than Xisha, has an earlier and greater increase in precipitation after SCSSMO under the combined effect of strong low-level southwesterly winds, coastal terrain blocking and lifting, and northern cold air. When the 950-h Pa southwesterly winds enhance and advance northward, accompanied by strengthened moisture flux, there is a strong convergence of wind and moisture in Dongsha due to a sudden deceleration and rear-end collision of wind by coastal terrain blocking. Moist and warm advection over Dongsha enhances early and deepens up to 200 h Pa in association with the strengthened upward motion after SCSSMO, thereby providing ample moisture and heat to form strong precipitation. However, when the 950-h Pa southwesterly winds weaken and retreat southward, Xisha is located in a wind-break area where strong convergence and upward motion centers move in. The vertical moistening and heating by advection in Xisha enhance later and appear far weaker compared to that in Dongsha, consistent with later and weaker precipitation. 展开更多
关键词 Dongsha Xisha South China Sea summer monsoon onset PRECIPITATION wind dynamics moisture HEAT
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Thornthwaite moisture index and depth of suction change under current and future climate‒An Australian study
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作者 Md Rajibul Karim Bikash Devkota +1 位作者 Md Mizanur Rahman Hoang Bao Khoi Nguyen 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第5期1761-1775,共15页
Climate change is one of the major global challenges and it can have a significant influence on the behaviour and resilience of geotechnical structures.The changes in moisture content in soil lead to effective stress ... Climate change is one of the major global challenges and it can have a significant influence on the behaviour and resilience of geotechnical structures.The changes in moisture content in soil lead to effective stress changes and can be accompanied by significant volume changes in reactive/expansive soils.The volume change leads to ground movement and can exert additional stresses on structures founded on or within a shallow depth of such soils.Climate change is likely to amplify the ground movement potential and the associated problems are likely to worsen.The effect of atmospheric boundary interaction on soil behaviour has often been correlated to Thornthwaite moisture index(TMI).In this study,the long-term weather data and anticipated future projections for various emission scenarios were used to generate a series of TMI maps for Australia.The changes in TMI were then correlated to the depth of suction change(H s),an important input in ground movement calculation.Under all climate scenarios considered,reductions in TMI and increases in H s values were observed.A hypothetical design scenario of a footing on expansive soil under current and future climate is discussed.It is observed that a design that might be considered adequate under the current climate scenario,may fail under future scenarios and accommodations should be made in the design for such events. 展开更多
关键词 Climate change Future prediction Thornthwaite moisture index(TMI) Characteristic surface movement Infrastructure resilience
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Comparison of CWSI and T_(s)-T_(a)-VIs in moisture monitoring of dryland crops(sorghum and maize)based on UAV remote sensing
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作者 Hui Chen Hongxing Chen +6 位作者 Song Zhang Shengxi Chen Fulang Cen Quanzhi Zhao Xiaoyun Huang Tengbing He Zhenran Gao 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2024年第7期2458-2475,共18页
Monitoring agricultural drought using remote sensing data is crucial for precision irrigation in modern agriculture.Utilizing unmanned aerial vehicle(UAV)remote sensing,we explored the applicability of an empirical cr... Monitoring agricultural drought using remote sensing data is crucial for precision irrigation in modern agriculture.Utilizing unmanned aerial vehicle(UAV)remote sensing,we explored the applicability of an empirical crop water stress index(CWSI)based on canopy temperature and three-dimensional drought indices(TDDI)constructed from surface temperature(T_(s)),air temperature(T_(a))and five vegetation indices(VIs)for monitoring the moisture status of dryland crops.Three machine learning algorithms(random forest regression(RFR),support vector regression,and partial least squares regression)were used to compare the performance of the drought indices for vegetation moisture content(VMC)estimation in sorghum and maize.The main results of the study were as follows:(1)Comparative analysis of the drought indices revealed that T_(s)-T_(a)-normalized difference vegetation index(TDDIn)and T_(s)-T_(a)-enhanced vegetation index(TDDIe)were more strongly correlated with VMC compared with the other indices.The indices exhibited varying sensitivities to VMC under different irrigation regimes;the strongest correlation observed was for the TDDIe index with maize under the fully irrigated treatment(r=-0.93).(2)Regarding spatial and temporal characteristics,the TDDIn,TDDIe and CWSI indices showed minimal differences Over the experimental period,with coefficients of variation were 0.25,0.18 and 0.24,respectively.All three indices were capable of effectively characterizing the moisture distribution in dryland maize and sorghum crops,but the TDDI indices more accurately monitored the spatial distribution of crop moisture after a rainfall or irrigation event.(3)For prediction of the moisture content of single crops,RFR models based on TDDIn and TDDIe estimated VMC most accurately(R^(2)>0.7),and the TDDIn-based model predicted VMC with the highest accuracy when considering multiple-crop samples,with R^(2)and RMSE of 0.62 and 14.26%,respectively.Thus,TDDI proved more effective than the CWSI in estimating crop water content. 展开更多
关键词 MAIZE SORGHUM T_(s)-T_(a)-VIs CWSI UAV machine learning crop moisture monitoring
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Quantifying Contribution of Recycled Moisture to Precipitation in Temperate Glacier Region,Southeastern Tibetan Plateau,China
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作者 MA Yanwei PU Tao +2 位作者 SHI Xiaoyi MA Xinggang YU Hongmei 《Chinese Geographical Science》 SCIE CSCD 2024年第4期764-776,共13页
Recycled moisture is an important indicator of the renewal capacity of regional water resources.Due to the existence of Yulong Snow Mountain,Lijiang in Yunnan Province,southeast of the Qinghai-Tibet Plateau,China,is t... Recycled moisture is an important indicator of the renewal capacity of regional water resources.Due to the existence of Yulong Snow Mountain,Lijiang in Yunnan Province,southeast of the Qinghai-Tibet Plateau,China,is the closest ocean glacier area to the equator in Eurasia.Daily precipitation samples were collected from 2017 to 2018 in Lijiang to quantify the effect of sub-cloud evaporation and recycled moisture on precipitation combined with the d-excess model during monsoon and non-monsoon periods.The results indicated that the d-excess values of precipitation fluctuated between–35.6‰and 16.0‰,with an arithmetic mean of 3.5‰.The local meteoric water line(LMWL)wasδD=7.91δ^(18)O+2.50,with a slope slightly lower than the global meteoric water line(GMWL).Subcloud evaporation was higher during the non-monsoon season than during the monsoon season.It tended to peak in March and was primarily influenced by the relative humidity.The source of the water vapour affected the proportion of recycled moisture.According to the results of the Hybrid Single-Particle Lagrangian Integrated Trajectory(HYSPLIT)model,the main sources of water vapour in Lijiang area during the monsoon period were the southwest and southeast monsoons.During the non-monsoon period,water vapour was transported by a southwesterly flow.The recycled moisture in Lijiang area between March and October 2017 was 10.62%.Large variations were observed between the monsoon and non-monsoon seasons,with values of 5.48%and 25.65%,respectively.These differences were primarily attributed to variations in the advection of water vapour.The recycled moisture has played a supplementary role in the precipitation of Lijiang area. 展开更多
关键词 recycled moisture stable isotope PRECIPITATION d-excess Hybrid Single-Particle Lagrangian Integrated Trajectory(HYSPLIT)model southeastern Tibetan Plateau China
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The lateral pressure coefficient at rest of expansive soils in landfill at various vertical stresses and moisture contents
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作者 ZHOU Zhen-hua KONG Ling-wei +2 位作者 SUN Zhi-liang LI Tian-guo YAN Jun-biao 《Journal of Mountain Science》 SCIE CSCD 2023年第4期1102-1117,共16页
When expansive soils in the original location are artificially transferred to landfill in different seasons,and subject to engineering activities afterwards,the corresponding deformation and stability of retaining str... When expansive soils in the original location are artificially transferred to landfill in different seasons,and subject to engineering activities afterwards,the corresponding deformation and stability of retaining structures become unpredictable.This necessitates the determination of lateral pressure coefficient at rest(k_(0) value)for expansive soils in landfill.Considering compaction,excavation of expansive soils,as well as construction of landfill in different seasons,series of stepwise loading and unloading consolidation tests at various moisture contents were carried out in this work to explore the evolution characteristics of k_(0) value and assess the dependence of k_(0) value on vertical stress and moisture content.Besides,scanning electron microscope(SEM)was used to track the change in microstructural features with vertical stresses.The results indicated that the k_(0) value of expansive soil shows a pronounced nonlinearity and is inextricably linked with vertical stress and moisture content,based on which a prediction formula to estimate the variation in k_(0) value with vertical stress during loading stage was proposed;there is a significant exponential increase in k_(0) value with overconsolidation ratio(OCR)during unloading stage,and OCR dominates the release of horizontal stress of expansive soil;SEM results revealed that with an increase in vertical stress,the anisotropy of expansive soil microstructure increases dramatically,causing a significant directional readjustment,which is macroscopically manifested as an initially rapid increase in k_(0) value;but when vertical stress increases to a critical value,the anisotropy of microstructure increases marginally,indicating a stable orientation occurring in the soil microstructure,which causes the k_(0) value to maintain a relatively stable value. 展开更多
关键词 Expansive soil k_(0)value LANDFILL Vertical stress moisture content
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Modelling the dead fuel moisture content in a grassland of Ergun City,China
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作者 CHANG Chang CHANG Yu +1 位作者 GUO Meng HU Yuanman 《Journal of Arid Land》 SCIE CSCD 2023年第6期710-723,共14页
The dead fuel moisture content(DFMC)is the key driver leading to fire occurrence.Accurately estimating the DFMC could help identify locations facing fire risks,prioritise areas for fire monitoring,and facilitate timel... The dead fuel moisture content(DFMC)is the key driver leading to fire occurrence.Accurately estimating the DFMC could help identify locations facing fire risks,prioritise areas for fire monitoring,and facilitate timely deployment of fire-suppression resources.In this study,the DFMC and environmental variables,including air temperature,relative humidity,wind speed,solar radiation,rainfall,atmospheric pressure,soil temperature,and soil humidity,were simultaneously measured in a grassland of Ergun City,Inner Mongolia Autonomous Region of China in 2021.We chose three regression models,i.e.,random forest(RF)model,extreme gradient boosting(XGB)model,and boosted regression tree(BRT)model,to model the seasonal DFMC according to the data collected.To ensure accuracy,we added time-lag variables of 3 d to the models.The results showed that the RF model had the best fitting effect with an R2value of 0.847 and a prediction accuracy with a mean absolute error score of 4.764%among the three models.The accuracies of the models in spring and autumn were higher than those in the other two seasons.In addition,different seasons had different key influencing factors,and the degree of influence of these factors on the DFMC changed with time lags.Moreover,time-lag variables within 44 h clearly improved the fitting effect and prediction accuracy,indicating that environmental conditions within approximately 48 h greatly influence the DFMC.This study highlights the importance of considering 48 h time-lagged variables when predicting the DFMC of grassland fuels and mapping grassland fire risks based on the DFMC to help locate high-priority areas for grassland fire monitoring and prevention. 展开更多
关键词 dead fuel moisture content(DFMC) random forest(RF)model extreme gradient boosting(XGB)model boosted regression tree(BRT)model GRASSLAND Ergun City
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Dry Matter Accumulation,Moisture Content in Maize Kernel and Their Influences on Mechanical Harvesting 被引量:17
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作者 阮龙 王俊 +4 位作者 陈义红 王世济 张玮 左晓龙 陈洪俭 《Agricultural Science & Technology》 CAS 2011年第12期1857-1860,共4页
[Objective] The aim of this study was to investigate the dry matter accumulation,moisture content in maize kernel and their influences on mechanical harvesting.[Methods] Using Zhengdan 958,Xianyu 335,Hongda 8 and Liyu... [Objective] The aim of this study was to investigate the dry matter accumulation,moisture content in maize kernel and their influences on mechanical harvesting.[Methods] Using Zhengdan 958,Xianyu 335,Hongda 8 and Liyu 16 as experimental materials,we preliminarily measured the dynamic changes of dry matter accumulation and moisture content with the days after pollination lasted,and investigated the effect of moisture content in kernels on mechanical harvesting of Zhengdan 958 and Liyu 16.[Results] During summer growing season,Zhengdan 958 and Liyu 16 became physiologically mature and suitable for harvesting at about 51 days after pollination,Xianyu 335 and Hongda 8 required 58 days to become physiologically mature and suitable for harvesting after pollination.At physiologically mature stage,the moisture contents in kernels of Zhengdan 958,Xianyu 335,Hongda 8 and Liyu 16 were respectively 33.74%,28.86%,32.05% and 35.24%,respectively.Adopting mechanical harvesting at physiologically mature stage,the kernel loss rate of Zhengdan 958 and Liyu 16 was consistent with the range of mechanical operation index(kernel loss rate of 0.84%≤2%),while the percentage of broken kernels did not accord with the range of mechanical operation index(kernel crashing rate of 10.12%≧1%).The results indicate that Zhengdan 958 and Liyu 16 are not suitable for mechanical harvesting using full feeding combine havester.[Conclusion] This study provided theoretical basis for improving the maize harvest index under delayed harvesting. 展开更多
关键词 Maize(Zea mays) Kernel weight moisture content Physiological mature stage
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Effects of Fertilization on Moisture Content of Soils in the Loess Hilly-gully Region 被引量:1
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作者 徐宣斌 高照良 《Agricultural Science & Technology》 CAS 2015年第2期278-280,共3页
[Objective] The aim of this study was to study the influence of plants on the soil moisture content under different fertilization.[Method] Using sainfoin,sweet clover,Astragalus adsurgens,alfalfa,ryegrass,little flowe... [Objective] The aim of this study was to study the influence of plants on the soil moisture content under different fertilization.[Method] Using sainfoin,sweet clover,Astragalus adsurgens,alfalfa,ryegrass,little flower,white clover as experimental material,this study explored the effects of soil moisture on the improvement of soil quality.[Result] Results showed that the soil moisture content of different plants follows as:sainfoin 〉sweet clover 〉Astragalus adsurgens 〉alfalfa perennial ryegrass 〉small crown 〉white clover,and the average moisture content reached 24.13% which was 2.45% higher than that of control group.At planting white clover,sweet clover,under the condition of 7 kinds of crops,in the treatments without fertilizer and with organic fertilizer,soil moisture content of soil in 0-20 cm grew significantly.[Conclusion] The application of organic fertilizer and growing of plants would improve soil moisture in abandoned fields,enhance the ability of soil water supply,and improve soil fertility. 展开更多
关键词 Plant FERTILIZER moisture content of soil Loess hilly-gully region
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Effects of Ground Mulching Treatments on Soil Moisture Content in Second-generation Seed Garden of Pinus elliottii
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作者 刘球 李志辉 +4 位作者 吴际友 陈明皋 李艳 程勇 黄明军 《Agricultural Science & Technology》 CAS 2016年第6期1355-1358,共4页
Different ground mulching treatments were designed to observe the effects on soil moisture content in a second-generation seed orchard of Pinus elliottii. The results showed that: (1) there were extreme differences... Different ground mulching treatments were designed to observe the effects on soil moisture content in a second-generation seed orchard of Pinus elliottii. The results showed that: (1) there were extreme differences in soil moisture content Ⅰ and soil moisture content Ⅲ, but no obvious difference in soil moisture content II was observed; and (2) the high-to-low order of soil moisture content Ⅰ under different ground mulching treatments was white film〉sawdust〉black film〉the control, and the highest value was higher than the lowest one by 26.69%; the high-to-low order of soil moisture content Ⅱ under different ground mulching treatments was white film〉black film〉sawdust〉the control, and the highest value was higher than the lowest one by 20.64%; and the high-to-low order of soil moisture content Ⅲ under different ground mulching treatments was black film〉white film〉sawdust〉the control, and the highest value was higher than the lowest one by 26.61%. 展开更多
关键词 Pinus elliottii Engelm Ground mulching Soil moisture content
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Effects of Soil Moisture Content and p H on Residual Dynamics of Chlorothalonil in Acidified Soil
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作者 王鸿斌 李雷 张洋 《Agricultural Science & Technology》 CAS 2015年第3期523-525,586,共4页
[Objective] This study aimed to investigate the residual dynamics of chlorothalonil in acidified soil under different conditions of soil moisture content and pH. [Method] By simulation tests, the effects of different ... [Objective] This study aimed to investigate the residual dynamics of chlorothalonil in acidified soil under different conditions of soil moisture content and pH. [Method] By simulation tests, the effects of different soil moisture content and pH on chlorothalonil residues in acidified soil were analyzed. [Result] Under different conditions of soil moisture content and pH, the residual quantity of chlorothalonil in acidified soil was reduced gradually with the extension of incubation time. To be specific, the reduction rate of chlorothalonil residues in soil was extremely high within the first three days and slightly declined at 3-7 d; after 7 d, the residual quantity of chlorothalonil in soil was reduced slowly and steadily. [Conclusion] This study provides the reference for soil environmental remediation and maintenance of a health cultivation system. 展开更多
关键词 CHLOROTHALONIL Soil pH Soil moisture content
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Real-time Monitoring Scheme of Soil Moisture Content in Paddy Field
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作者 贾宏伟 胡荣祥 刘威琼 《Agricultural Science & Technology》 CAS 2013年第11期1679-1682,共4页
The monitoring of soil moisture content in paddy field is one of important parts and contents of regional soil moisture monitoring. But a good monitoring scheme hasn’t been established. A real-time monitoring scheme ... The monitoring of soil moisture content in paddy field is one of important parts and contents of regional soil moisture monitoring. But a good monitoring scheme hasn’t been established. A real-time monitoring scheme of soil moisture content in paddy field was put forward from two key links of soil moisture content monitoring and field water-layer monitoring. This scheme could meet the alternative monitoring requirements of soil moisture content in water layer and none-water layer. It had a good maneuverability and could provide references for practical work. 展开更多
关键词 Paddy field moisture content Soil moisture content Field water-layer Real-time monitoring
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