Spatial and temporal variability of soil horizons and long-term solute transport under semi-arid conditions

2013 ◽  
Vol 93 (2) ◽  
pp. 173-191 ◽  
Author(s):  
S. A. Woods ◽  
M. F. Dyck ◽  
R. G. Kachanoski
Keyword(s):  
Spatial Distribution ◽  
Water Balance ◽  
Soil Water ◽  
Temporal Variability ◽  
Soil Water Balance ◽  
Spatial And Temporal Variability ◽  
Soil Horizons ◽  
Deep Drainage ◽  
Semi Arid

Woods, S. A., Dyck, M. F. and Kachanoski, R. G. 2013. Spatial and temporal variability of soil horizons and long-term solute transport under semi-arid conditions. Can. J. Soil Sci. 93: 173–191. Characterizing the spatial and temporal variability of deep drainage is required for quantifying risks to groundwater resources associated with chemicals released into the soil. A variety of approaches are available to characterize the spatial variability of deep drainage, including complex, spatially explicit hydrological models or simpler, distributed soil water balance models. There is no clear understanding which approach is most appropriate for a given landscape. In this paper we compare the spatial distribution of an applied chloride tracer to pedogenic nitrate and sulphate salts, subject to transport in the soil over decadal to millennial time scales, to characterize the relative spatial and temporal differences in deep drainage at a site in southern Saskatchewan. Comparison of the spatial distribution of the salts with differing soil residence times showed that the soil water balance and deep drainage fluxes have changed significantly over time in some parts of the landscape because of infilling of surface depressions as indicated by the presence of buried A horizons. At larger scales, the distribution of the salts showed very little correspondence to the spatial distribution and thicknesses of soil horizons (often used to infer spatial variability in soil water balance), but was more consistent with the scale of the surface topography. Thus it was concluded that spatial and temporal changes in surface topography (i.e., catchment area) were the primary factors responsible for the observed transport of the salts. We propose that this site is representative of the cold, semi-arid prairies and that these conclusions likely apply to this region.

scholarly journals Soil Water Balance and Vegetation Dynamics in a Semi-arid Mediterranean Ecosystem

Proceedings ◽  
2020 ◽  
Vol 30 (1) ◽  
pp. 76
Author(s):  
Ioannis N. Daliakopoulos ◽  
Ioanna Panagea ◽  
Luca Brocca ◽  
Erik van den Elsen
Keyword(s):  
Water Balance ◽  
Soil Water ◽  
Water Availability ◽  
Vegetation Dynamics ◽  
Soil Water Balance ◽  
Mediterranean Ecosystem ◽  
Limiting Factor ◽  
Arid Conditions ◽  
Water Balance Models ◽  
Semi Arid

Under arid conditions, where water availability is the limiting factor for plant survival, water balance models can be used to explain vegetation dynamics. [...]

Comparative performance of soil water balance models in computing semi-arid aquifer recharge

2013 ◽  
Vol 59 (1) ◽  
pp. 193-203 ◽  
Author(s):  
I. Touhami ◽  
J.M. Andreu ◽  
E. Chirino ◽  
J.R. Sánchez ◽  
A. Pulido-Bosch ◽  
...  
Keyword(s):  
Water Balance ◽  
Soil Water ◽  
Soil Water Balance ◽  
Aquifer Recharge ◽  
Comparative Performance ◽  
Water Balance Models ◽  
Semi Arid

scholarly journals General procedure to initialize the cyclic soil water balance by the Thornthwaite and Mather method

2010 ◽  
Vol 67 (1) ◽  
pp. 87-95 ◽  
Author(s):  
Durval Dourado-Neto ◽  
Quirijn de Jong van Lier ◽  
Klaas Metselaar ◽  
Klaus Reichardt ◽  
Donald R. Nielsen
Keyword(s):  
Water Balance ◽  
Soil Water ◽  
General Procedure ◽  
Water Storage ◽  
Dry Season ◽  
Soil Water Balance ◽  
Soil Water Storage ◽  
Wet Season ◽  
Water Balance Components ◽  
Semi Arid

The original Thornthwaite and Mather method, proposed in 1955 to calculate a climatic monthly cyclic soil water balance, is frequently used as an iterative procedure due to its low input requirements and coherent estimates of water balance components. Using long term data sets to establish a characteristic water balance of a location, the initial soil water storage is generally assumed to be at field capacity at the end of the last month of the wet season, unless the climate is (semi-) arid when the soil water storage is lower than the soil water holding capacity. To close the water balance, several iterations might be necessary, which can be troublesome in many situations. For (semi-) arid climates with one dry season, Mendonça derived in 1958 an equation to quantify the soil water storage monthly at the end of the last month of the wet season, which avoids iteration procedures and closes the balance in one calculation. The cyclic daily water balance application is needed to obtain more accurate water balance output estimates. In this note, an equation to express the water storage for the case of the occurrence of more than one dry season per year is presented as a generalization of Mendonça's equation, also avoiding iteration procedures.

scholarly journals In situ unsaturated zone water stable isotope (<sup>2</sup>H and <sup>18</sup>O) measurements in semi-arid environments: a soil water balance

2016 ◽  
Vol 20 (2) ◽  
pp. 715-731 ◽  
Author(s):  
Marcel Gaj ◽  
Matthias Beyer ◽  
Paul Koeniger ◽  
Heike Wanke ◽  
Josefina Hamutoko ◽  
...  
Keyword(s):  
Stable Isotopes ◽  
Water Balance ◽  
Soil Water ◽  
Root Zone ◽  
Soil Water Balance ◽  
Vacuum Extraction ◽  
Rain Event ◽  
Arid Environments ◽  
Semi Arid

Abstract. Stable isotopes (deuterium, 2H, and oxygen-18, 18O) of soil water were measured in the field using a liquid water isotope analyzer (tunable off-axis integrated cavity output spectroscope, OA-ICOS, LGR) and commercially available soil gas probes (BGL-30, UMS, Munich) in the semi-arid Cuvelai–Etosha Basin (CEB), Namibia. Results support the applicability of an in situ measurement system for the determination of stable isotopes in soil pore water. High spatial and temporal resolution was achieved in the study area with reasonable accuracy and measurements were in agreement with laboratory-based cryogenic vacuum extraction and subsequent cavity ring-down laser spectroscopic isotope analysis (CRDS, L2120-i, Picarro Inc.). After drift and span correction of the in situ isotope data, precision for over 140 measurements taken during two consecutive field campaigns (June and November 2014) was 1.8 and 0.48 ‰ for δ2H and δ18O, respectively. Mean measurement trueness is determined using quality check standards and was 5 and 0.3 ‰ for δ2H and δ18O, respectively. The isotope depth profiles are used quantitatively to calculate a soil water balance. The contribution of transpiration to total evapotranspiration ranged between 72 and 92 %. Shortly after a rain event, the contribution of transpiration was much lower, at 35 to 50 %. Potential limitations of such an in situ system are related to environmental conditions which could be minimized by using a temperature-controlled chamber for the laser spectrometer. Further, the applicability of the system using previously oven-dried soil material might be limited by physicochemical soil properties (i.e., clay minerals). Uncertainty in the in situ system is suggested to be reduced by improving the calibration procedure and further studying fractionation effects influencing the isotope ratios in the soil water, especially at low water contents. Furthermore, the influence of soil-respired CO2 on isotope values within the root zone could not be deduced from the data.

scholarly journals Assessing Irrigation Water Use with Remote Sensing-Based Soil Water Balance at an Irrigation Scheme Level in a Semi-Arid Region of Morocco

2021 ◽  
Vol 13 (6) ◽  
pp. 1133
Author(s):  
Mohamed Hakim Kharrou ◽  
Vincent Simonneaux ◽  
Salah Er-Raki ◽  
Michel Le Page ◽  
Saïd Khabba ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Water Balance ◽  
Soil Water ◽  
Irrigation Water ◽  
Management Practices ◽  
Irrigation District ◽  
Soil Water Balance ◽  
Balance Model ◽  
Irrigation Water Use ◽  
Semi Arid

This study aims to evaluate a remote sensing-based approach to allow estimation of the temporal and spatial distribution of crop evapotranspiration (ET) and irrigation water requirements over irrigated areas in semi-arid regions. The method is based on the daily step FAO-56 Soil Water Balance model combined with a time series of basal crop coefficients and the fractional vegetation cover derived from high-resolution satellite Normalized Difference Vegetation Index (NDVI) imagery. The model was first calibrated and validated at plot scale using ET measured by eddy-covariance systems over wheat fields and olive orchards representing the main crops grown in the study area of the Haouz plain (central Morocco). The results showed that the model provided good estimates of ET for wheat and olive trees with a root mean square error (RMSE) of about 0.56 and 0.54 mm/day respectively. The model was then used to compare remotely sensed estimates of irrigation requirements (RS-IWR) and irrigation water supplied (WS) at plot scale over an irrigation district in the Haouz plain through three growing seasons. The comparison indicated a large spatio-temporal variability in irrigation water demands and supplies; the median values of WS and RS-IWR were 130 (175), 117 (175) and 118 (112) mm respectively in the 2002–2003, 2005–2006 and 2008–2009 seasons. This could be attributed to inadequate irrigation supply and/or to farmers’ socio-economic considerations and management practices. The findings demonstrate the potential for irrigation managers to use remote sensing-based models to monitor irrigation water usage for efficient and sustainable use of water resources.

scholarly journals Maximising the use of soil water by herbaceous species in the high rainfall zone of southern Australia: a review

2003 ◽  
Vol 54 (7) ◽  
pp. 677 ◽  
Author(s):  
D. K. Singh ◽  
P. R. Bird ◽  
G. R. Saul
Keyword(s):  
Water Balance ◽  
Soil Water ◽  
Water Use ◽  
Dry Matter ◽  
Soil Water Balance ◽  
Balance Model ◽  
Herbaceous Species ◽  
Deep Drainage ◽  
High Rainfall ◽  
Pasture Productivity

The planting of deep-rooted pasture species, herbaceous shrubs, and trees has been widely recommended to reduce deep drainage and recharge to the groundwater in the high rainfall zone (HRZ). However, in more recent years, the value of perennial pastures to reduce recharge has been questioned in areas with >600 mm annual rainfall. Currently, pastures dominated by annual species with relatively low productivity occur across much of the HRZ where deep drainage is most likely contributing to recharge. This review outlines our current understanding of water use by various herbaceous species, and indicates ways in which their water use may be increased in the HRZ of southern Australia. To reduce deep drainage in the HRZ, the soil water deficit must be increased prior to the opening autumn rains. This will allow a greater storage of water before any potential deep drainage occurs. There are two ways that this can be achieved with the use of herbaceous species. Firstly, change to or encourage species that use more water annually. Although plants with deeper root systems including lucerne have the ability to dry the soil to depth, a combination of winter- and summer-active species, rotational grazing, and pasture spelling would extend the active growing season and soil water use of annual and perennial species. A second option is to increase the productivity of the pasture, as there is a direct link between growth and water use. For example, improving pasture productivity by 50%, say from 8 to 12 t dry matter/ha, could use (transpire) approximately 160 mm more water annually by a C3 species, irrespective of evaporation from the soil surface or evaporative demand factors. This is supported by strong correlations between plant dry mass and water use among a wide range of C3 and C4 plants of diverse growth form and habitat. This relationship appears to have been overlooked in recent studies of various components of the soil water balance model, possibly due to limited and unreliable estimates of evapotranspiration (ET). An improved relationship between 'estimated' ET and measured dry matter production should improve the capability of the soil water balance model to predict deep drainage, which is primarily dependent on the ET. Ways to increase pasture productivity and soil water use include regular applications of fertiliser and lime, and better management of waterlogged and acidic soils in the HRZ. Summer-active native species may also be useful on soils where the persistence of other deep-rooted perennials is poor; however, little is known about their productivity and persistence when heavily grazed.We believe that the relationship between water use and pasture production needs to be reassessed to improve the predictability of the soil water balance approach and recommend further research in both the field and under controlled conditions to determine the potential for increased water use in the HRZ of southern Australia by combinations of plant species and greater pasture productivity.

scholarly journals The impact of climate change on soil water balance and agricultural production sustainability in Mediterranean part of Bosnia and Herzegovina

2020 ◽  
Vol 53 (1) ◽  
pp. 125
Author(s):  
Melisa Ljusa ◽  
Hamid Custovic ◽  
Sabina Hodzic
Keyword(s):  
Water Balance ◽  
Soil Water ◽  
Bosnia And Herzegovina ◽  
Calculated Data ◽  
Vegetation Period ◽  
Soil Water Balance ◽  
Monthly Precipitation ◽  
The World ◽  
The Impact

<p>The world agriculture uses about 70% of the world water resources in irrigation. The concern over the sustainability of water use as demand for agricultural, industrial, and domestic uses continues to increase. Conflicts between particular sectors result in tensions, which sometimes lead to “water wars” in different parts of the world. It is the reason why many national and international organizations are putting the water quantity and quality questions on the top of the world’s open questions/problems. The main aim of this paper is to present soil water balance of the Mediterranean region of Bosnia and Herzegovina, prepared for a long-term time series for two locations (Trebinje and Mostar) annually and during the vegetation period. The mean long-term data has been used as a base for future predicted calculation. The predicted PET was based on an increase in air temperature by 2°C and predicted decrease in precipitation by 25%. With so predicted calculated data of monthly PET and monthly precipitation the predicted soil water balance was done.</p>

Sign in / Sign up

Export Citation Format

Share Document