scholarly journals Volume Changes in Undisturbed Clay Profiles in Western Canada

1963 ◽  
Vol 1 (1) ◽  
pp. 27-42 ◽  
Author(s):  
J J Hamilton
Keyword(s):  
Soil Moisture ◽  
Unsaturated Soils ◽  
Free Water ◽  
Thermal Conditions ◽  
Climatic Conditions ◽  
Western Canada ◽  
Undisturbed Soil ◽  
Temperature And Precipitation ◽  
Frost Penetration ◽  
Moisture Conditions

As part of an over-all study of the performance of building foundations in highly plastic soil areas of western Canada, the Division of Building Research has been measuring ground movements and changes in soil moisture conditions in grass-covered, undisturbed soil profiles under climatic conditions ranging from sub-humid to semi-arid. Results of measurements begun in 1951 in Winnipeg, Manitoba, and more recently those in Regina, Eston, and Tisdale, Saskatchewan, are reported. Results of a theoretical soil moisture depletion calculation, based on Thornthwaite's potential evapo-transpiration concept, are presented. It is proposed as a more rational way of measuring the vegetation-climate factor in humid to sub-humid climates than simply comparing air temperature and precipitation with long-term averages. Empirical relationships are suggested between calculated soil moisture depletion, the depth of free water table, and the depth of frost penetration under similar thermal conditions but different soil moisture conditions. Shrinkage in situ of undisturbed, unsaturated soils at temperatures well below 32° F has been observed and is attributed to thermal air-void volume change.

Climatic conditions for seedling recruitment within perennial grass swards in south-eastern Australia

2012 ◽  
Vol 63 (4) ◽  
pp. 389 ◽  
Author(s):  
R. Thapa ◽  
D. R. Kemp ◽  
M. L. Mitchell
Keyword(s):  
Soil Moisture ◽  
New South ◽  
Perennial Grass ◽  
New South Wales ◽  
Climatic Conditions ◽  
South Eastern ◽  
South Wales ◽  
Eastern Australia ◽  
Moisture Conditions ◽  
South Eastern Australia

Recruitment of new perennial grass plants within existing grassland ecosystems is determined by seed availability, suitable microsites, nutrients and climatic conditions, water and temperatures. This paper reports on the development of criteria to predict recruitment events using modelled soil moisture conditions associated with recruitment of species in five field experiments at Orange (Phalaris aquatica), Trunkey Creek (Austrodanthonia spp.), and Wellington (Bothriochloa macra) in central New South Wales, Australia, and the frequency of those conditions during the past 30 years. Recruitment events were recorded when a rainfall event (median 68 mm across the three sites) kept the surface volumetric soil moisture (0–50 mm) above the permanent wilting point for at least 15 continuous days, allowing for, at most, two ‘dry days’ in between. A key finding from our study is that rainfall events creating favourable soil moisture conditions for seedling emergence typically occurred in the second half of February, sometimes extending to early March. Previously it was thought that recruitment would more likely occur through autumn, winter, and spring when rainfall in southern Australia is more reliable. The 30 years’ data (1975–2004) showed that the P. aquatica site had a median of 20 continuous moist days each year in February–March, whereas, there were 16 and 10 days for the Austrodanthonia and B. macra sites, respectively. The probabilities of exceeding seven or 15 continuous days of moist surface soil were 98% and 78% at the P. aquatica site, 91% and 49% at the Austrodanthonia site, and 73% and 30% at the B. macra site, and indicated that some recruitment is possible in most years. These analyses were extended to several sites across New South Wales, Victoria, and Tasmania to estimate the frequency with which recruitment could occur within natural swards. Across these sites, the probabilities of exceeding seven continuous days of soil moisture were >55% and of exceeding 15 continuous days were lower, which showed that suitable climatic conditions exist during late summer–early autumn across south-eastern Australia for a recruitment event to occur. Future research may show that the criteria developed in this paper could have wider regional application.

scholarly journals Interplays between State and Flux Hydrological Variables across Vadose Zones: A Numerical Investigation

Water ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1295 ◽  
Author(s):  
Wang ◽  
Wang ◽  
Zhang
Keyword(s):  
Soil Moisture ◽  
Vadose Zone ◽  
Hydraulic Properties ◽  
Climatic Conditions ◽  
Zone Model ◽  
Residual Soil ◽  
Soil Hydraulic Properties ◽  
Soil Hydraulic ◽  
Moisture Conditions ◽  
Hydrological Variables

Knowledge of both state (e.g., soil moisture) and flux (e.g., actual evapotranspiration (ETa) and groundwater recharge (GR)) hydrological variables across vadose zones is critical for understanding ecohydrological and land-surface processes. In this study, a one-dimensional process-based vadose zone model with generated soil hydraulic parameters was utilized to simulate soil moisture, ETa, and GR. Daily hydrometeorological data were obtained from different climate zones to drive the vadose zone model. On the basis of the field phenomenon of soil moisture temporal stability, reasonable soil moisture spatiotemporal structures were reproduced from the model. The modeling results further showed that the dependence of ETa and GR on soil hydraulic properties varied considerably with climatic conditions. In particular, the controls of soil hydraulic properties on ETa and GR greatly weakened at the site with an arid climate. In contrast, the distribution of mean relative difference (MRD) of soil moisture was still significantly correlated with soil hydraulic properties (most notably residual soil moisture content) under arid climatic conditions. As such, the correlations of MRD with ETa and GR differed across different climate regimes. In addition, the simulation results revealed that samples with average moisture conditions did not necessarily produce average values of ETa and GR (and vice versa), especially under wet climatic conditions. The loose connection between average state and flux hydrological variables across vadose zones is partly because of the high non-linearity of subsurface processes, which leads to the complex interactions of soil moisture, ETa, and GR with soil hydraulic properties. This study underscores the importance of using soil moisture information from multiple sites for inferring areal average values of ETa and GR, even with the knowledge of representative sites that can be used to monitor areal average moisture conditions.

scholarly journals Evaluation of the infiltration capacity of soil in a winter wheat stand during the growing season 2010

2011 ◽  
Vol 59 (6) ◽  
pp. 225-234
Author(s):  
Tomáš Mašíček ◽  
František Toman ◽  
Martina Vičanová ◽  
Věra Hubačíková
Keyword(s):  
Soil Moisture ◽  
Winter Wheat ◽  
Field Measurements ◽  
Growing Season ◽  
Specific Weight ◽  
Infiltration Capacity ◽  
Undisturbed Soil ◽  
Volume Weight ◽  
Basin Irrigation ◽  
Moisture Conditions

The aim of the presented paper was to map the course of infiltration during the growing season of 2010 in a winter wheat stand on a selected locality in the Sazomín cadastral area on the basis of selected hydro-physical properties of soil (specific weight, reduced volume weight, actual soil moisture, absorptivity, retention water capacity, porosity, capillary, semi-capillary and non-capillary pores and aeration) evaluated from the analyses of undisturbed soil samples. In order to assess the infiltration capacity of soil at the U Jasana locality in the season April–October, four surveys were realized always with three measurements within each of the surveys. The measurement of infiltration took place in the form of basin irrigation. To evaluate field measurements of infiltration empirical relations were used, namely Kostiakov equations. The highest cumulative infiltration and speed of infiltration were noted in June at the high actual soil moisture and closed stand. In case of October measurement, effects of agro-technical operations became evident on the slightly lower infiltration capacity of soil as compared to June measurements at nearly identical moisture conditions. The lowest infiltration capacity of soil reaching the same level, namely in spite of different moisture conditions and the stand character (July – full-grown stand, August – stubble-field) was found in July and August.

Soil moisture conditions and pine failure at Waarre, near Port Campbell, Victoria

1962 ◽  
Vol 13 (3) ◽  
pp. 426 ◽  
Author(s):  
T Poutsma ◽  
KJ Simpfendorfer
Keyword(s):  
Soil Moisture ◽  
Ground Water ◽  
Correlation Coefficient ◽  
Pinus Radiata ◽  
Free Water ◽  
Water Levels ◽  
Lateral Movement ◽  
Monterey Pine ◽  
Shallow Wells ◽  
Moisture Conditions

The pines in the Forests Commission plantation at Waarre, near Port Campbell in Victoria, are marked by large and widespread differences in vigour, and in some cases even by virtual failure. To investigate this condition the presence of and changes in free water levels in the soils were followed at 16 sites on the plantation. This was done by means of shallow wells 30 in. deep, and piezometers sunk to a depth of 5½ ft. Observations extended over 28 months. The results showed that surface waterlogging is widely present on the plantation. This surface waterlogging is seasonal, and it varies in severity from year to year in accordance with the rainfall. "Free" ground-water is absent from nearly all the deep subsoils. The vigour of the pine cover was found to vary significantly with the degree of surface waterlogging. For Monterey pine (Pinus radiata D. Don) the correlation coefficient for nine sites was 0.82**, and for maritime pine (P. pinaster Ait.) the correlation coefficient for six sites was 0.81*. This relationship appears to be modified by the lateral movement of free water through the surface horizons. Nutrient trials have also shown a slow but marked response to additions of superphosphate.

Hydro-climatic drivers of mid-winter break-up of river ice in western Canada and Alaska

2016 ◽  
Vol 48 (4) ◽  
pp. 945-956 ◽  
Author(s):  
B. W. Newton ◽  
T. D. Prowse ◽  
L. P. de Rham
Keyword(s):  
Ice Cover ◽  
Climatic Conditions ◽  
River Ice ◽  
Western Canada ◽  
The North ◽  
Temperature And Precipitation ◽  
Tropospheric Circulation ◽  
Climatic Drivers ◽  
Break Up

The mid-winter break-up of a competent river ice cover can cause ice jamming and flooding, which can have profound impacts on the structure and strength of the ice cover. This research identifies 52 mid-winter break-up events in western Canada (1950–2008) and Alaska (1950–2014) and evaluates the hydro-climatic drivers including temperature and precipitation. The identified mid-winter break-up events are primarily located in the temperate zone, defined as the region between 400 and 1,000 winter (December–February) freezing degree-days. Further delineation by terrestrial biome revealed considerable variability in hydro-climatic triggers, particularly the role of freeze-thaw days (Tmax > 0 °C and Tmin < 0 °C) in Tundra and Boreal Forest/Taiga biomes and short-term (3-day) warming events in Temperate Coniferous Forests and Temperate Grasslands, Savannas, and Shrublands. The classification of 5-day sequences of mid-tropospheric circulation indicates that a persistent trough of low-pressure over Alaska and the North Pacific is the dominant pattern preceding mid-winter break-ups. Furthermore, the trough is stronger for events in British Columbia and Alberta compared with Alaska and the Yukon. The results of this research improve our understanding of the hydro-climatic conditions that generate mid-winter break-up events in western Canada and Alaska and will aid in the prediction and risk management of such events.

scholarly journals Design of Smart Garden Based On The Internet of Things (IoT)

2021 ◽  
Vol 3 (2) ◽  
pp. 36-40
Author(s):  
Atmiasri ◽  
Andika Tri Wiyono
Keyword(s):  
Soil Moisture ◽  
Internet Of Things ◽  
Technological Progress ◽  
Human Error ◽  
Climatic Conditions ◽  
Cultivated Plants ◽  
Moisture Sensor ◽  
Soil Moisture Sensor ◽  
Moisture Conditions ◽  
Prototype Design

Currently, the control of cultivated plants is still manual, where farmers watering and checking soil moisture on the planting object. However, we cannot avoid technological progress in this life because technological progress will run following scientific advances. Therefore, every innovation is created to provide positive benefits for life. The ideal chili cultivation planning requires information about climatic conditions that play a significant role in chili cultivation is rainfall. Plant growth will be incredible if there is sufficient water supply; humidity for chili plants ranges from 60-80%. Therefore, chili cultivation planning must pay attention to rainfall because related to water availability. Smart Garden prototype design is a solution for taking appropriate actions during extreme weather and reducing human error. A prototype Smart Garden-based Internet of Things (IoT) using the Blynk app as User Interface (GUI) in the monitoring system and using the Soil Moisture sensor as input for soil moisture conditions, where the results of the process are sent via Wemos D1 mini-module to the Blynk server to display the state of soil moisture and automatic watering.

Modeling snowpack and soil temperature and moisture conditions in a jack pine, black spruce and aspen forest stand in central Saskatchewan (BOREAS SSA)

2006 ◽  
Vol 86 (Special Issue) ◽  
pp. 203-217 ◽  
Author(s):  
Vincent Balland, Jagtar Bhatti ◽  
Ruth Errington, Mark Castonguay ◽  
Paul A. Arp
Keyword(s):  
Soil Moisture ◽  
Soil Temperature ◽  
Populus Tremuloides ◽  
Forest Floor ◽  
Black Spruce ◽  
Jack Pine ◽  
Soil Freezing ◽  
Moisture Retention ◽  
Frost Penetration ◽  
Moisture Conditions

Impacts of climate change on above- and below-ground heat and moisture conditions were modeled so that other impacts on, e.g., local carbon (C) and C-based pools for nutrients and pollutants such as Hg can be predicted reliably. This paper shows how the 199–-2003 data for the jack pine (jp; Pinus banksiana Lamb.), black spruce (bs; Picea mariana) and aspen (ta; Populus tremuloides) sites of the Southern Study Area of the BOREAS project were used to estimate some of the hydrothermal soil responses at these locations to daily variations in precipitation and air temperature. This was done by initializing and calibrating a forest hydrology model that has the capacity to simulate flow and retention of moisture and heat, as modified by canopy closure, ground cover, forest-floor depth, and soil composition. The calculations and data revealed strong but predictable site-specific differences in soil temperature and frost penetration (jp: 1–2 m > ta: 0.5–1 m > bs: 0–0.5 m), in soil moisture freezing (ta < bs < jp), and in moisture retention (jp < ta < bs). Apart from daily weather, these differences depended on soil texture (loamy/sandy texture impeded/encouraged soil freezing, respectively), and on the thermal insulation and moisture retention of the combined forest floor, moss and lichens layers (ta < jp < bs). Key words: Jack pine, aspen, black spruce, soil moisture, soil temperature, frost penetration, snowpack, boreal conditions

Exploring the use of Standardized Soil Moisture as a Drought Indicator

2021 ◽  
Author(s):  
Ronald D. Leeper ◽  
Bryan Petersen ◽  
Michael A. Palecki ◽  
Howard Diamond
Keyword(s):  
Soil Moisture ◽  
Agricultural Drought ◽  
Reference Network ◽  
Standardized Measures ◽  
Temperature And Precipitation ◽  
Local Soil ◽  
Drought Conditions ◽  
Monitoring And Forecasting ◽  
Upper Level ◽  
Moisture Conditions

AbstractAgricultural drought has traditionally been monitored using indices based on above ground measures of temperature and precipitation that have lengthy historical records. However, the period-of-record length for soil moisture networks are becoming sufficient enough to standardize and evaluate soil moisture anomalies and percentiles that are spatially and temporally independent of local soil type, topography, and climatology. To explore these standardized measures in the context of drought, the U. S. Climate Reference Network (USCRN) hourly standardized soil moisture anomalies and percentiles were evaluated against changes in the U.S. Drought Monitor (USDM) status, with a focus on onset, worsening, and improving drought conditions. The purpose of this study was to explore timescales (i.e., 1 to 6 weeks) and soil moisture at individual (i.e., 5, 10, 20, 50, and 100 cm) and aggregated layer (i.e., Top and Column) depths to determine those that were more closely align with evolving drought conditions. Results indicated that the upper-level depths (5, 10, and 20 cm, and Top layer aggregate) and shorter averaging periods were more responsive to changes in USDM drought status. This was particularly evident during the initial and latter stages of drought when USDM status changes were thought to be more aligned with soil moisture conditions. This indicates that standardized measures of soil moisture can be useful in drought monitoring and forecasting applications during these critical stages of drought formation and amelioration.

scholarly journals Observing soil moisture temporal variability under fluctuating climatic conditions

2008 ◽  
Vol 5 (2) ◽  
pp. 935-969 ◽  
Author(s):  
A. Longobardi
Keyword(s):  
Soil Moisture ◽  
Climatic Conditions ◽  
Annual Rainfall ◽  
Dry Period ◽  
Experimental Site ◽  
Rainfall Variation ◽  
Dry Soil ◽  
Moisture Conditions ◽  
Increasing Precipitation

Abstract. The paper focuses on the observation of interannual and intra-annual climate variability impact on soil moisture temporal patterns and variation, for an experimental site located in Southern Italy and characterized by a typical Mediterranean climate. Analysed data consist of three years soil water content time series measured during the period 2004–2007, under intermediate (2004/2005), wet (2005/2006) and dry (2006/2007) climatological conditions. Results show that, for the case study, interannual precipitation fluctuation highly impact the annual soil moisture cycle, modifying the number and length of characteristic periods revealed by the cycle patterns. Annual rainfall variation also affects the weight of the wet and dry soil moisture conditions, making the distinction between preferred states more and more evident for increasing precipitation variability. Intra-annual precipitation fluctuation instead mainly impact soil moisture dynamic during the dry period of the year, shifting the position of the modes and the weight of the wet mode and nearly leading the dry mode to disappear for larger mean seasonal rainfall. Reported analyses would be a support and a premise for further modeling implications.

Sign in / Sign up

Export Citation Format

Share Document