scholarly journals True water constraint under a rainfall interception experiment in a Mediterranean shrubland (Northern Tunisia): confronting discrete measurements with a plant–soil water budget model

Plant Ecology ◽  
2014 ◽  
Vol 215 (7) ◽  
pp. 779-794 ◽  
Author(s):  
Damien Longepierre ◽  
Florent Mouillot ◽  
Bahri Ouelhazi ◽  
Jean Marc Ourcival ◽  
Alain Rocheteau ◽  
...  
Keyword(s):  
Soil Water ◽  
Water Budget ◽  
Rainfall Interception ◽  
Northern Tunisia ◽  
Budget Model ◽  
Plant Soil ◽  
Mediterranean Shrubland ◽  
Water Constraint

OBSERVED AND ESTIMATED SEASONAL SOIL WATER VARIATIONS UNDER NONIRRIGATED SOD

1969 ◽  
Vol 49 (2) ◽  
pp. 181-188 ◽  
Author(s):  
W. Baier
Keyword(s):  
Soil Water ◽  
Water Budget ◽  
Soil Classification ◽  
Coefficient Of Determination ◽  
Standard Errors ◽  
Climatic Data ◽  
Wet Season ◽  
Total Period ◽  
Plant Soil ◽  
Available Soil Moisture

Variations of soil water content under nonirrigated sod at Ottawa during 10 seasons were analyzed using 5-day means of daily resistance readings from Colman units. A meteorological water budget making use of standard climatic data and accounting for physical properties of the soil provided estimates of soil water which resembled the measured values. The coefficient of determination for 5-day means of observed soil water, correlated with the estimates, varied from 0.34 in a wet season to 0.84 in a dry season, and was 0.73 over the whole 10-year period. Standard errors of estimates were between 4 and 25% of the seasonal mean of available soil moisture, and 15% for the total period. It was concluded that, for climatic and soil classification purposes, estimates from this meteorological budgeting technique are sufficiently accurate to be used for interpreting plant–soil–water interactions over past periods, for which climatological but not soil water observations are available.

Utility of a simple soil water budget model in agronomic research. 2. Estimates of available soil water in relation to profile changes of soil water content and potential

1974 ◽  
Vol 14 (66) ◽  
pp. 80 ◽  
Author(s):  
RG Fawcett ◽  
OG Carter
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Water Budget ◽  
Plant Density ◽  
Budget Model ◽  
North West ◽  
The North ◽  
South Wales ◽  
Profile Changes

A study was made of the effects of plant density, time-of-sowing and level of fallow water on profile changes in soil water content and potential during the growing season of spring wheat. The pattern of soil moisture extraction was affected by all treatments although water depletion occurred chiefly in the 0-90 cm zone. The results are discussed in relation to limitations of a simple soil water budget model and to wheat cropping on the north-west slopes and plains of New South Wales.

Utility of a simple soil water budget model in agronomic research. 3. Estimation of the potential evapotranspiration function

1974 ◽  
Vol 14 (70) ◽  
pp. 684
Author(s):  
RG Fawcett ◽  
OG Carter
Keyword(s):  
Soil Water ◽  
Water Budget ◽  
Potential Evapotranspiration ◽  
Regression Equation ◽  
Wheat Crop ◽  
Budget Model ◽  
Plant Densities ◽  
Potential Transpiration

It has been shown that a regression equation relating the cumulative potential transpiration function (T/Eo) with the yield of tops, week of sowing and available fallow moisture, together with a simple budget model, can be used to estimate weekly changes in available soil water under a wheat crop. It is concluded from the data that use of the equation and budget model should be most suited to situations where plant densities are about 60 plants per m2 and the available fallow water is about 150 mm or less.

Utility of a simple soil water budget model in agronomic research. 1. Effects of plant density, time of sowing and fallow water on available soil water under spring wheat

1973 ◽  
Vol 13 (65) ◽  
pp. 714 ◽  
Author(s):  
RG Fawcett ◽  
OG Carter
Keyword(s):  
Soil Water ◽  
Spring Wheat ◽  
Water Budget ◽  
Field Experiments ◽  
Plant Density ◽  
New South ◽  
Growing Season ◽  
Wheat Cultivars ◽  
Budget Model ◽  
South Wales

A simple soil water budget model was used to estimate weekly changes in available soil water as affected by plant density, time of sowing and level of available fallow water for spring wheat cultivars grown on a black earth in northern New South Wales. Estimated values of available water were mostly within �10 mm of observed values (ranging from 50-270 mm) obtained at four intervals during the growing season. The results are discussed in relation to both the interpretation of agronomic field experiments and use of the model in regions where conserved fallow water contributes significantly to cereal production.

scholarly journals Integrating MODIS images in a water budget model for dynamic functioning and drought simulation of a Mediterranean forest in Tunisia

2012 ◽  
Vol 9 (5) ◽  
pp. 6251-6284 ◽  
Author(s):  
H. Chakroun ◽  
F. Mouillot ◽  
M. Nouri ◽  
Z. Nasr
Keyword(s):  
Soil Water ◽  
Water Budget ◽  
Regional Scale ◽  
Field Capacity ◽  
Stress Index ◽  
Climatic Data ◽  
Natural Ecosystem ◽  
Stress Monitoring ◽  
Budget Model ◽  
Vegetation Stress

Abstract. The use of remote sensing at different spatio-temporal resolutions is being common during the last decades since sensors offer many inputs to water budget estimation. Various water balance models use the LAI as a parameter for accounting water interception, evapotranspiration, runoff and available ground water. The objective of the present work is to improve vegetation stress monitoring at regional scale for a natural forested ecosystem. LAI-MODIS and spatialized vegetation, soil and climatic data have been integrated in a water budget model that simulates evapotranspiration and soil water content at daily step. We first explore LAI-MODIS in the specific context of Mediterranean natural ecosystem. Results showed that despite coarse resolution of LAI-MODIS product (1 km), it was possible to discriminate evergreen and coniferous vegetation and that LAI values are influenced by underlying soil capacity of water holding. The dynamic of vegetation has been integrated into the water budget model by weekly varying LAI-MODIS. Results of simulations were analysed in terms of actual evapotranspoiration, deficit of soil water to field capacity and vegetation stress index based on actual and potential evapotranspiration. Comparing dynamic LAI variation, afforded by MODIS, to a hypothetic constant LAI all over the year correspond to 30% of fAPAR increase. A sensitivity analysis of simulation outputs to this fAPAR variation reveals that increase of both deficit of soil water to field capacity and stress index are respectively 18% and 27%, (in terms of RMSE, these variations are respectively 1258 mm yr−1 and 11 days yr−1). These results are consistent with previous studies led at local scale showing that LAI increase is accompanied by stress conditions increase in Mediterranean natural ecosystems. In this study, we also showed that spatial modelisation of drought conditions based on water budget simulations is an adequate tool for quantifying expositions of different species to stress and for analysing most influent factors on ecosystem vulnerability to drought.

A SOIL WATER BUDGET MODEL WITH A NEARLY IMPERMEABLE LAYER

1981 ◽  
Vol 61 (2) ◽  
pp. 361-371 ◽  
Author(s):  
R. DE JONG ◽  
C. F. SHAYKEWICH
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Water Budget ◽  
Budget Model ◽  
Sink Term ◽  
Impermeable Layer ◽  
Homogeneous Soil ◽  
Potential Transpiration ◽  
System Water ◽  
Water Contents

A soil water budget model which accounted for a nearly impermeable layer in the profile was developed to describe the water content in a non-homogeneous soil-root system. Water uptake by the roots was represented by a sink term which was dependent upon the root distribution, the soil water content and the potential transpiration. The chosen boundary conditions, precipitation, evapotranspiration and a nearly impermeable layer at the bottom of the soil profile approximated those existing in the field. A submodel to calculate interception was included in the model. Data obtained from a field experiment on a clay soil were compared with calculated results for the period 1 May to 30 Sept. 1975. The overall agreement between daily measured and calculated soil water contents was excellent; all calculated values fell within 10% of the measured data. The model also yielded acceptable results in predicting the distribution of soil water through the profile.

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