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International Soil and water Conservation Research 2023年第2期11卷 382-392页

作者： Mutiu Abolanle Busarit Ganiyu Olawale Bankole Idris Adebanjo Adiamo Rasaq Olayiwola Abiodun Olanrewaju Hammed Ologunde Department of Soil Science and Land Management Federal University of AgricultureAbeokutaPM.B2240AbeokutaNigeria

Sustainable vegetable production especially during the dry season requires adequate conservation of soil *** study was conducted to evaluate the sole and interactive effects of mulching(M)and poultry manure(PM)application on soil temperature(ST),crop evapotranspiration(ETc)and water use efficiency(WUE)of *** experiment was a Randomized Complete Block Design(RCBD)with three *** treatments were M at 0 and 6t ha^(-1)and PM at 0,10 and 20t ha^(-1).Soil temperature was measured using digital thermometer while ETc was determined by water depletion method using a Time Domain *** at field capacity was applied manually at 2-day *** appli-cation of mulch significantly lowered ST while joint application of 20t ha^(-1)PM(PM20)and M signifi-cantly(p≤0.05)reduced ST at 5 cm and 10 cm soil depth compared with the unmulched plots in both *** of 10t ha^(-1)PM(PM10)without M recorded the highest ETc(43.7 mm),while joint application of PM20 and M reduced ETc by about 93%compared with PM10 *** used water most efficiently when PM20 was applied under mulched *** was 62.2%increase in WUE under mulched plots compared with the control while the residual effect of PM10 and M significantly increased WUE by 65.5%.It was evident that M alongside application of PM is a good strategy for regulating ST,moderating ETc and increasing okra WUE,especially during dry season farming.

关键词： Evapotranspiration Soil temperature volumetric water content water depletion method water use efficiency

Natural consolidation characteristics of viscous debris flow deposition

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Journal of Mountain Science 2016年第10期13卷 1723-1734页

作者： HE Song-Tang WANG Dao-Jie CHEN Shun ZHANG Shu-Juan CHANG Shi-Qiu Key Laboratory of Mountain Hazards and Earth Surface Processes Chinese Academy of SciencesChengdu 610041China Institute of Mountain Hazards and Environment Chinese Academy of Science&Ministry of Water ConservancyChengdu 510041China University of Chinese Academy of Sciences Beijing 100049China

Pore water pressure and water content are important indicators to both deposition and consolidation of debris flows, enabling a direct assessment of consolidation degree. This article gained a more comprehensive understanding about the entire consolidation process and focused on exploring pore water pressure and volumetric water content variations of the deposit body during natural consolidation under different conditions taking the viscous debris flow mass as a study subject and by flume experiments. The results indicate that, as the color of the debris changed from initial dark green to grayish-white color, the initial deposit thickness declined by 3% and 2.8% over a permeable and impermeable sand bed, respectively. A positive correlation was observed between pore water pressure and depth in the deposit for both scenarios, with deeper depths being related to greater pore water pressure. For the permeable environment, the average dissipation rate of pore water pressure measured at depths of 0.10 m and 0.05 m were 0.0172 Pa/d and 0.0144 Pa/d, respectively, showing a positivechanging trend with increasing depth. Under impermeable conditions, the average dissipation rates at different depths were similar, while the volumetric water content in the deposit had a positive correlation with depth. The reduction of water content in the deposit accelerated with depth under impermeable sand bed boundary conditions, but was not considerably correlated with depth under permeable sand bed boundary conditions. However, the amount of discharged water from the deposit was greater and consolidation occurred faster in permeable conditions. This indicates that the permeability of the boundary sand bed has a significant impact on the progress of consolidation. This research demonstrates that pore water and pressure dissipations are present during the entire viscous debris consolidation process. Contrasting with dilute flows, pore pressure dissipation in viscous flows cannot be complete

关键词： Viscous debris flow Natural consolidation Dissipation of pore water pressure volumetric water content Flume experiment

Soil Hydraulic Properties： Influence of Tillage and Cover Crops

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Pedosphere 2018年第3期28卷 430-442页

作者： Samuel I. HARUNA Stephen H. ANDERSON Nsalambi V. NKONGOLO Syaharudin ZAIBON School of Agriculture College of Basic and Applied Sciences Middle Tennessee State University 1301 East Main Street Murfreesboro TN 37132-0001( USA) Department of Soil Environmental and Atmospheric Sciences 302 Anheuser-Busch Natural Resources Building University of Mis-souri Columbia MO 65211-0001( USA) Institut Facultaire des Sciences Agronomiques (IFA-Yangambi) Boite Postale Kisangani 1232( Democratic Republic of Congo) Department of Land Management Faculty of Agriculture University Putra Malaysia 43400 Serdang Selangor Malaysia

Understanding the effects of cover crops and tillage on soil physical properties is important for determining soil productivity. This study was conducted at Lincoln University＇s Freeman Center, USA to evaluate the effects of tillage and cover crop management on soil hydraulic properties. The field site included three replicate blocks in a randomized complete block design with each plot measuring 21.3 m in length and 12.2 m in width. Treatment factors were tillage at two levels （moldboard plow tillage vs. no tillage） and cover crop at two levels （cereal rye （Secale cereal） cover crop vs. no cover crop）. Soil samples were collected in late spring/early summer from each treatment at 10-cm depth increments from the soil surface to a depth of 40 cm using cores （76.2-mm diameter and 76.2-mm length）. Soil bulk density was 13% lower with tillage compared with no-tillage. volumetric water content was significantly higher at 0.0 and -0.4 kPa pressures with tillage compared with no tillage. Tillage increased the proportion of coarse mesopores by 32gc compared with no tillage, resulting in 87% higher saturated hydraulic conductivity （Ksat）. Cover crop increased the proportion of macropores by 24~ compared with no cover crop; this can potentially increase water infiltration and reduce runoff. As a result of higher macroporosity, Ksat was higher under cover crop compared with no cover crop. This study demonstrated that tillage can benefit soil hydraulic properties in the short term, but these effects may not persist over time. Cover crops may slightly improve soil hydraulic properties, but longer term studies are needed to evaluate the long-term effects.

关键词： pore size distribution saturated hydraulic conductivity soil bulk density soil water retention volumetric water content

Performance evaluation and calibration of capacitance sensor for estimating the salinity of reclaimed land

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International Journal of Agricultural and Biological Engineering 2020年第1期13卷 206-210页

作者： Donggeun Kim Younghwan Son Jaesung Park Taejin Kim Jihun Jeon Department of Rural Systems Engineering Seoul National UniversitySeoul 08826Republic of Korea Department of Rural Systems Engineering and Research Institute for Agriculture and Life SciencesSeoul National UniversitySeoul 08826Republic of Korea Department of Bioresource Engineering McGill UniversitySte-Anne-de-Bellevue QC H9X 3V9Canada

Generally,soil moisture and salinity in reclaimed land are monitored using soil dielectric sensors such as time domain reflectometry,frequency domain reflectometry,and *** soil dielectric sensor measures apparent dielectric ***,apparent dielectric permittivity is affected by soil moisture,salinity,and *** this study,performance evaluation and calibration of a dielectric sensor(5TE;METER Group,Inc.,Pullman,WA,USA)for monitoring soil salinity were *** calibration tests were completed,incorporating various levels of dry density,water content,and *** soil salinity was determined by the electrical conductivity(EC)1:5 *** volumetric water content as measured by the sensor was affected by dry density and water ***,it linearly increased as dry density and water content ***,when dry density or water content was high,the measured value of the sensor increased *** bulk EC measured by sensor had no specific correlation with EC 1:*** EC 1:5 measurement had a linear relationship with the gradient ofθandθ***,it can be estimated with a simple linear equation usingθfrom the soil test andθs from the capacitance *** R 2 value of the EC 1:5 estimation equation was *** proposed equation requiresθfrom the gravimetric sample andθs from the ***,in the case of monitoring salinity using a sensor,it is recommended to measure the water content with a tensiometer.

关键词： salinity capacitance sensor volumetric water content reclaimed land soil saline soil

Study of water Movement in Unsaturated Copper Ore

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Journal of China University of Mining and Technology 2007年第4期17卷 516-520页

作者： LI Xun YANG Ze-ping ZHENG Zhi-hong College of Engineering and Architecture Zhefiang University Hangzhou Zhejiang 310027 China East China Institute of Technology Fuzhou Jiangxi 344000 China

Leaching is widely applied in the exploitation of depleted ores. In order to discover the law of leachant movement in the leaching process and calculating volumes and time intervals of spraying leachant,experiments and numerical simulation with the TOUGH2/EOS3 module were carried out in order to find out the principle of water movement in unsaturated copper ore. The results show that water volume increases at the same location over time,that copper ore tends to become saturated and that liquid velocity decreases at the same time as the distance from top in-creases. On the other hand,a comparison and analysis of our experimental and simulated results indicate that the EOS3 module could accurately simulate the water movement in an unsaturated state.

关键词： unsaturated copper ore volumetric water content liquid velocity simulation

Proposal of a Method to Easily Understand Rainfall Infiltration in Railway Embankments

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Journal of Civil Engineering and Architecture 2024年第6期18卷 261-268页

作者： Takashi Nakayama Tadashi Hara Keigo Koizumi C.S.Inspector Co. Ltd.2-7-2 Nambanaka Naniwa-Ku Osaka-ShiOsaka-Fu 556-0011Japan Research and Education Faculty Kochi University2-5-1 Akebonocho Kochi-ShiKochi-Ken 780-8072Japan Earth Watch Institute Inc.8-10 Toyotsucho Suita-ShiOsaka-Fu 564-0051Japan

Slope failures due to heavy or prolonged rain have been occurring frequently in Japan in recent *** railway embankments,even small-scale surface collapse can result in track ***,train operation during rainy periods is regulated according to empirical rules based on rainfall and disaster ***,the validity of operation regulations is lacking because the rainfall infiltration circumstances inside the slope are *** have been attempting to understand rainfall infiltration in railway embankments by applying a method of predicting surface collapse from observations of volumetric water content in the *** used previous field monitoring and model experiments to propose a method for easily understanding the state of rainfall infiltration in the surface layer of an embankment using the relative history of volumetric water content at different *** this study,we applied this simple determination method to railway embankments with different topography and geological environments to demonstrate the versatility of the method.

关键词： Railway embankments field monitoring volumetric water content

Stability Analysing of Unsaturated Soil Slope

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Journal of China University of Mining and Technology 2003年第1期13卷 55-59页

作者：张士林邵龙潭 School of Civil and Hydraulic Engineering Dalian University of Technology Department of Engineering Mechanics Dalian University of Technology

The stability of unsaturated soil slope has been the hot point recently. Especially, the seeping rainfall makes losing stability of unsaturated soil slope, and causes enormous loss to the producation and safety of other people. The seeping rainfall makes volumetric water content of unsaturated soil slope changing, and the volumetric water content has directly relationship with matric suction. And matric suction also has directly relationship with the stability of unsaturated soil slope. So the change of matric suction influence the stability changing, that is, safety coefficient has decided relationship with volumetric water content. The profile of dangerous volumetric water content curves of unsaturated soil slope has been obtained. If a volumetric water content curve of some unsaturated soil slope belongs to one of these dongerous curves, the unsaturated soil slope could be in danger. So this is called DVWCCP(dangerous volumetric water content curves profile). By monitoring the volumetric water content curves can obtain the stability information of some soil slope to serve producing and safety.

关键词： unsaturated soil stability analysis seeping rainfall volumetric water content matric suction DVWCCP