Research on inversion of soil water dynamic parameters by field soil moisture content

Author(s):  
Wang Yang-ren ◽  
Li Yan ◽  
Sun Shu-hong ◽  
Zhou Qing-yun ◽  
Han Na-na
2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Lijun Hou ◽  
Yuan Wang ◽  
Fengchun Shen ◽  
Ming Lei ◽  
Xiang Wang ◽  
...  

The self-designed indoor simulated rainfall device was used to rain on five types of pavement structures with 4 types of rainfall intensity (2.5 mm/min, 3.4 mm/min, 4.6 mm/min, and 5.5 mm/min). The effect of rainfall intensity on the surface runoff, the relation between the subgrade soil moisture content changes, and the influence of initial soil water content on rain infiltration rate are studied. The test results show that the surface runoff coefficient of densely asphalted pavement is greater than 90% in drainage pavements and it has little influence on the reducing and hysteresis of the flood peak. The surface runoff coefficient of large-void asphalt pavement (permeable) is less than 40%. Although the large-void asphalt pavement (permeable) can reduce a small amount of surface runoff, it has no obvious effect on the reduction and hysteresis of the flood peak. In semipermeable pavement, with the increasing of the thickness of base (graded gravel), the surface runoff coefficient decreases at different rainfall intensities, parts of the surface runoff are reduced, and the arrival of flood peaks is delayed. In permeable roads, almost no surface runoff occurred. As time continued, the soil moisture content quickly reached a saturated state and presented a stable infiltration situation under the action of gravity and the gradient of soil water suction. As the initial moisture content increases, the initial infiltration rate decreases and the time to reach a stable infiltration rate becomes shorter. The drier the soil, the greater the initial infiltration rate and the higher the soil moisture content after infiltration stabilization. Permeable roads can greatly alleviate the pressure of urban drainage and reduce the risk of storms and floods.


Biologia ◽  
2017 ◽  
Vol 72 (8) ◽  
Author(s):  
Gábor Milics ◽  
Attila J. Kovács ◽  
Attila Pörneczi ◽  
Anikó Nyéki ◽  
Zoltán Varga ◽  
...  

AbstractSoil moisture content directly influences yield. Mapping within field soil moisture content differences provides information for agricultural management practices.In this study we aimed to find a cost-effective method for mapping within field soil moisture content differences. Spatial coverage of the field sampling or TDR method is still not dense enough for site-specific soil management. Soil moisture content can be calculated by measuring the apparent soil electrical conductivity (Soil moisture map was also compared to yield map showing correlation (


2011 ◽  
Author(s):  
IV Berney ◽  
Kyzar Ernest S. ◽  
Oyelami James D. ◽  
Lawrence O.

Water ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1731 ◽  
Author(s):  
Michał Śpitalniak ◽  
Krzysztof Lejcuś ◽  
Jolanta Dąbrowska ◽  
Daniel Garlikowski ◽  
Adam Bogacz

Climate change induces droughts that are becoming more intensive and more frequent than ever before. Most of the available forecast tools predict a further significant increase in the risk of drought, which indicates the need to prepare solutions to mitigate its effects. Growing water scarcity is now one of the world’s leading challenges. In agriculture and environmental engineering, in order to increase soil water retention, soil additives are used. In this study, the influence of a newly developed water absorbing geocomposite (WAG) on soil water retention and soil matric potential was analyzed. WAG is a special element made from geotextile which is wrapped around a synthetic skeleton with a superabsorbent polymer placed inside. To describe WAG’s influence on soil water retention and soil matric potential, coarse sand, loamy sand, and sandy loam soils were used. WAG in the form of a mat was used in the study as a treatment. Three kinds of samples were prepared for every soil type. Control samples and samples with WAG treatment placed at depths of 10 cm and 20 cm were examined in a test container of 105 × 70 × 50 cm dimensions. The samples had been watered and drained, and afterwards, the soil surface was heated by lamps of 1100 W total power constantly for 72 h. Soil matric potential was measured by Irrometer field tensiometers at three depths. Soil moisture content was recorded at six depths: of 5, 9, 15, 19, 25, and 30 cm under the top of the soil surface with time-domain reflectometry (TDR) measurement devices. The values of soil moisture content and soil matric potential were collected in one-minute steps, and analyzed in 24-h-long time steps: 24, 48, and 72 h. The samples with the WAG treatment lost more water than the control samples. Similarly, lower soil matric potential was noted in the samples with the WAG than in the control samples. However, after taking into account the water retained in the WAG, it appeared that the samples with the WAG had more water easily available for plants than the control samples. It was found that the mechanism of a capillary barrier affected higher water loss from soil layers above those where the WAG had been placed. The obtained results of water loss depend on the soil type used in the profile.


2013 ◽  
Vol 807-809 ◽  
pp. 178-183
Author(s):  
Jin Feng Yang ◽  
Cheng Jun Zhang ◽  
Tong Ke Zhao ◽  
Qiong Wu

Bioventing is an in situ forced oxidative soil remediation technology which combined soil vapor extraction with biodegradation. It has broad application prospects of soil contamination caused by underground storage tank leakage. Orthogonal experiment as a high efficiency, rapid and economical experimental design method has been widely used in many research. In order to enhance bioventing and shorten the cycle of pollution control,it is necessary to study the mechanism of the interaction among the different factors to quantify the interaction and accelerate the degradation rate. In this study, five factors (initial diesel concentration, venting mode, pore volume number during soil venting, soil moisture content and the ratio of carbon, nitrogen and phosphate) which influence bioventing was chosen to conduct orthogonal experiment of the remediation of diesel contaminated soil by enhancing bioventing. The results show that: 1)Initial diesel concentration and soil moisture content have main effects on the remediation of diesel contaminated soil by bioventing, then the ratio of carbon, nitrogen and phosphate and pore volume number during soil venting. Venting mode has the weakest effect. 2)When 40mg oil/g soil of diesel concentration, air injecting from the bottom of column, 4 vk·d-1 of the pore volume number during soil venting, 100:20:1 of the ratio of carbon, nitrogen and phosphate and soil water content for 20% of the maximum of soil water holding capacity, that would reach a larger removal rate.


2017 ◽  
Vol 44 (10) ◽  
pp. 1007
Author(s):  
Jian-Jun Wang ◽  
Wei-Hu Lin ◽  
Yan-Ting Zhao ◽  
Cheng Meng ◽  
An-Wei Ma ◽  
...  

The interaction effects between temperature and soil moisture on Festuca sinensis Keng ex E.B.Alexeev were analysed to determine how F. sinensis responds to these environmental conditions. A pot experiment was conducted in a greenhouse under simulated growth conditions with four soil moisture contents (80, 65, 50 and 35% relative saturation moisture content) and three temperature conditions (15, 20 and 25°C). Physiological (relative water content and root activity) and biochemical parameters (chlorophyll, peroxidase (POD), malondialdehyde (MDA), soluble protein, soluble sugar and free proline) were evaluated at the seedling stage. Results showed that with a decrease in soil water content, the POD activities, MDA content, soluble protein content, soluble sugar content and free proline content of plants under the 15°C and 20°C treatments initially decreased and then increased, whereas they increased with a decrease of soil water content at 25°C. The relative water contents of plants under the three temperature treatments decreased with a decreasing soil moisture content, but then increased temperature significantly reduced the relative water content of the seedlings under low soil water content. The chlorophyll contents of plants under the 25°C treatment decreased with a decrease of soil moisture content, but those of plants under the 15°C and 20°C treatments initially increased and then decreased. The root activities of plants under the 15°C and 20°C treatments increased with a decreasing soil moisture content; however, those of plants under the 25°C treatment initially increased and then decreased. Thus, results indicated that changes of temperature and soil moisture content had significant and complicated effects on the physiological-biochemical characteristics of F. sinensis; the conditions of 20°C and 65% RSMC had positive effects on F. sinensis seedling growth and the appropriate drought stress could promote the growth of seedling roots under the three different temperature conditions. In conclusion, F. sinensis seedlings could adapt to certain changes in the ecological environment by regulating their physiological and biochemical reactions.


Water ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 222
Author(s):  
Wenkai Lei ◽  
Hongyuan Dong ◽  
Pan Chen ◽  
Haibo Lv ◽  
Liyun Fan ◽  
...  

In order to understand the hydrological process of expansive soil slopes, simulated rainfall experiments were conducted to study the effects of slope gradient and initial soil moisture content on runoff and infiltration for expansive soil slopes located in south China. The field program consisted of four neighboring slopes (70%, 47%, 32%, and 21%) instrumented by a runoff collection system and moisture content sensors (EC-5). Results from the monitored tests indicate that there was delay in the response of surface runoff. The runoff initiation time decreased with initial soil water content and increasing slope gradient. After the generation of runoff, the cumulative runoff per unit area and the runoff rate increased linearly and logarithmically with time, respectively. The greater the initial soil moisture content was, the smaller the influence of slope gradient on runoff. A rainfall may contribute from 39% to about 100% of its total rainfall as infiltration, indicating that infiltration remained an important component of the rainwater falling on the slope, despite the high initial soil water content. The larger the initial sealing degree of slope surface was the smaller the cumulative infiltration per unit area of the slope. However, the soil moisture reaction was more obvious. The influence of inclination is no longer discernible at high initial moisture levels. The greater the initial soil moisture content and the smaller the slope gradient, the weaker was the change of soil water content caused by simulated rainfall. The influence of initial soil moisture content and slope gradient on the processes of flow and changes of soil water content identified in this study may be helpful in the surface water control for expansive soil slopes.


Weed Science ◽  
1970 ◽  
Vol 18 (1) ◽  
pp. 110-111 ◽  
Author(s):  
R. Grover

A somewhat modified version of Lambert's quantitative treatment of the influence of soil-moisture content on herbicidal activity has been applied to 4-amino-3,5,6-trichloropicolinic acid (picloram) behavior in soil. The bioactivity of picloram decreased as the soil-moisture content was increased. This was due to the effect of varying soil-moisture levels on the concentration of picloram in the soil-water phase.


Sign in / Sign up

Export Citation Format

Share Document