scholarly journals Qualitative soil moisture assessment in semi-arid Africa: the role of experience and training on inter-rater reliability

2015 ◽  
Vol 12 (3) ◽  
pp. 3029-3058
Author(s):  
M. Rinderer ◽  
H. Komakech ◽  
D. Müller ◽  
J. Seibert
Keyword(s):  
Soil Moisture ◽  
Classification Scheme ◽  
Functional Relation ◽  
Soil Surface ◽  
Arid Environment ◽  
Rater Reliability ◽  
Moisture Conditions ◽  
And Training ◽  
Semi Arid

Abstract. Soil and water management is particularly relevant in semi-arid regions to enhance agricultural productivity. During periods of water scarcity soil moisture differences are important indicators of the soil water deficit and are traditionally used for allocating water resources among farmers of a village community. Here we present a simple, inexpensive soil wetness classification scheme based on qualitative indicators which one can see or touch on the soil surface. It incorporates the local farmers' knowledge on the best soil moisture conditions for seeding and brick making in the semi-arid environment of the study site near Arusha, Tanzania. The scheme was tested twice in 2014 with farmers, students and experts (April: 40 persons, June: 25 persons) for inter-rater reliability, bias of individuals and functional relation between qualitative and quantitative soil moisture values. During the test in April farmers assigned the same wetness class in 46% of all cases while students and experts agreed in about 60% of all cases. Students who had been trained in how to apply the method gained higher inter-rater reliability than their colleagues with only a basic introduction. When repeating the test in June, participants were given improved instructions, organized in small sub-groups, which resulted in a higher inter-rater reliability among farmers. In 66% of all classifications farmers assigned the same wetness class and the spread of class assignments was smaller. This study demonstrates that a wetness classification scheme based on qualitative indicators is a robust tool and can be applied successfully regardless of experience in crop growing and education level when an in-depth introduction and training is provided. The use of a simple and clear layout of the assessment form is important for reliable wetness class assignments.

scholarly journals Qualitative soil moisture assessment in semi-arid Africa – the role of experience and training on inter-rater reliability

2015 ◽  
Vol 19 (8) ◽  
pp. 3505-3516 ◽  
Author(s):  
M. Rinderer ◽  
H. C. Komakech ◽  
D. Müller ◽  
G. L. B. Wiesenberg ◽  
J. Seibert
Keyword(s):  
Soil Moisture ◽  
Classification Scheme ◽  
Functional Relation ◽  
Soil Surface ◽  
Arid Environment ◽  
Rater Reliability ◽  
Moisture Conditions ◽  
And Training ◽  
Semi Arid

Abstract. Soil and water management is particularly relevant in semi-arid regions to enhance agricultural productivity. During periods of water scarcity, soil moisture differences are important indicators of the soil water deficit and are traditionally used for allocating water resources among farmers of a village community. Here we present a simple, inexpensive soil wetness classification scheme based on qualitative indicators which one can see or touch on the soil surface. It incorporates the local farmers' knowledge on the best soil moisture conditions for seeding and brick making in the semi-arid environment of the study site near Arusha, Tanzania. The scheme was tested twice in 2014 with farmers, students and experts (April: 40 persons, June: 25 persons) for inter-rater reliability, bias of individuals and functional relation between qualitative and quantitative soil moisture values. During the test in April farmers assigned the same wetness class in 46 % of all cases, while students and experts agreed on about 60 % of all cases. Students who had been trained in how to apply the method gained higher inter-rater reliability than their colleagues with only a basic introduction. When repeating the test in June, participants were given improved instructions, organized in small subgroups, which resulted in a higher inter-rater reliability among farmers. In 66 % of all classifications, farmers assigned the same wetness class and the spread of class assignments was smaller. This study demonstrates that a wetness classification scheme based on qualitative indicators is a robust tool and can be applied successfully regardless of experience in crop growing and education level when an in-depth introduction and training is provided. The use of a simple and clear layout of the assessment form is important for reliable wetness class assignments.

scholarly journals Improvement of the Soil Moisture Retrieval Procedure Based on the Integration of UAV Photogrammetry and Satellite Remote Sensing Information

2021 ◽  
Vol 13 (24) ◽  
pp. 4968
Author(s):  
Amal Chakhar ◽  
David Hernández-López ◽  
Rocío Ballesteros ◽  
Miguel A. Moreno
Keyword(s):  
Soil Moisture ◽  
Bare Soil ◽  
Arid Environment ◽  
Early Growth ◽  
Precise Determination ◽  
Growth Stages ◽  
Crop Fields ◽  
Moisture Conditions ◽  
Semi Arid ◽  
Cultivated Soils

In countries characterized by arid and semi-arid climates, a precise determination of soil moisture conditions on the field scale is critically important, especially in the first crop growth stages, to schedule irrigation and to avoid wasting water. The objective of this study was to apply the operative methodology that allowed surface soil moisture (SSM) content in a semi-arid environment to be estimated. SSM retrieval was carried out by combining two scattering models (IEM and WCM), supplied by backscattering coefficients at the VV polarization obtained from the C-band Synthetic Aperture Radar (SAR), a vegetation descriptor NDVI obtained from the optical sensor, among other essential parameters. The inversion of these models was performed by Neural Networks (NN). The combined models were calibrated by the Sentinel 1 and Sentinel 2 data collected on bare soil, and in cereal, pea and onion crop fields. To retrieve SSM, these scattering models need accurate measurements of the roughness surface parameters, standard deviation of the surface height (hrms) and correlation length (L). This work used a photogrammetric acquisition system carried on Unmanned Aerial Vehicles (UAV) to reconstruct digital surface models (DSM), which allowed these soil roughness parameters to be acquired in a large portion of the studied fields. The obtained results showed that the applied improved methodology effectively estimated SSM on bare and cultivated soils in the principal early growth stages. The bare soil experimentation yielded an R2 = 0.74 between the estimated and observed SSMs. For the cereal field, the relation between the estimated and measured SSMs yielded R2 = 0.71. In the experimental pea fields, the relation between the estimated and measured SSMs revealed R2 = 0.72 and 0.78, respectively, for peas 1 and peas 2. For the onion experimentation, the highest R2 equaled 0.5 in the principal growth stage (leaf development), but the crop R2 drastically decreased to 0.08 in the completed growth phase. The acquired results showed that the applied improved methodology proves to be an effective tool for estimating the SSM on bare and cultivated soils in the principal early growth stages.

scholarly journals Effects of antecedent soil moisture on runoff modeling in small semiarid watersheds of southeastern Arizona

2011 ◽  
Vol 15 (10) ◽  
pp. 3171-3179 ◽  
Author(s):  
Y. Zhang ◽  
H. Wei ◽  
M. A. Nearing
Keyword(s):  
Soil Moisture ◽  
Standard Deviation ◽  
Soil Layer ◽  
Arid Environment ◽  
Storm Events ◽  
Runoff Generation ◽  
Antecedent Soil Moisture ◽  
Small Watersheds ◽  
Runoff Modeling ◽  
Moisture Conditions

Abstract. This study presents unique data on the effects of antecedent soil moisture on runoff generation in a semi-arid environment, with implications for process-based modeling of runoff. The data were collected from four small watersheds measured continuously from 2002 through 2010 in an environment where evapo-transpiration approaches 100% of the infiltrated water on the hillslopes. Storm events were generally intense and of short duration, and antecedent volumetric moisture conditions were dry, with an average in the upper 5 cm soil layer over the nine year period of 8% and a standard deviation of 3%. Sensitivity analysis of the model showed an average of 0.05 mm change in runoff for each 1% change in soil moisture, indicating an approximate 0.15 mm average variation in runoff accounted for by the 3% standard deviation of measured antecedent soil moisture. This compared to a standard deviation of 4.7 mm in the runoff depths for the measured events. Thus the low variability of soil moisture in this environment accounts for a relative lack of importance of storm antecedent soil moisture for modeling the runoff. Runoff characteristics simulated with a nine year average of antecedent soil moisture were statistically identical to those simulated with measured antecedent soil moisture, indicating that long term average antecedent soil moisture could be used as a substitute for measured antecedent soil moisture for runoff modeling of these watersheds. We also found no significant correlations between measured runoff ratio and antecedent soil moisture in any of the four watersheds.

Endogenous jasmonates in dry and imbibed sunflower seeds from plants grown at different soil moisture contents

2007 ◽  
Vol 17 (2) ◽  
pp. 91-98 ◽  
Author(s):  
Ana Vigliocco ◽  
Sergio Alemano ◽  
Otto Miersch ◽  
Daniel Alvarez ◽  
Guillermina Abdala
Keyword(s):  
Soil Moisture ◽  
Environmental Conditions ◽  
Differential Sensitivity ◽  
Sunflower Seeds ◽  
Seed Progeny ◽  
Hormonal Content ◽  
Tolerant Line ◽  
Sensitive Line ◽  
Moisture Conditions

AbstractIn this study, we characterized two sunflower (Helianthus annuus L.) lines with differential sensitivity to drought, the sensitive line B59 and the tolerant line B71. Using both lines, we compared the content of endogenous jasmonates (JAs) in dry and imbibed seeds from plants grown under irrigation and drought. Jasmonic acid (JA), 12-oxo-phytodienoic acid (OPDA), 11-hydroxyjasmonate (11-OH-JA) and 12-hydroxyjasmonate (12-OH-JA) were detected in dry and imbibed sunflower seeds. Seeds from plants grown under drought had a lower content of total JAs and exhibited higher germination percentages than seeds from irrigated plants, demonstrating that environmental conditions have a strong influence on the progeny. OPDA and 12-OH-JA were the main compounds found in dry seeds of both lines. Imbibed seeds showed an enhanced amount of total JAs with respect to dry seeds produced by plants grown in both soil moisture conditions. Imbibition triggered a dramatic OPDA increase in the embryo, suggesting a role of this compound in germination. We conclude that JAs patterns vary during sunflower germination and that the environmental conditions experienced by the mother plant modify the hormonal content of the seed progeny.

scholarly journals The role of surface water redistribution in an area of patterned vegetation in a semi-arid environment, south-west Niger

1997 ◽  
Vol 198 (1-4) ◽  
pp. 1-29 ◽  
Author(s):  
J. Bromley ◽  
J. Brouwer ◽  
A.P. Barker ◽  
S.R. Gaze ◽  
C. Valentine
Keyword(s):  
Surface Water ◽  
Arid Environment ◽  
South West ◽  
Water Redistribution ◽  
Semi Arid

Reliability of the Artemisia/Chenopodiaceae pollen ratio in differentiating vegetation and reflecting moisture in arid and semi-arid China

The Holocene ◽  
2020 ◽  
Vol 30 (6) ◽  
pp. 858-864 ◽  
Author(s):  
Yuan Wang ◽  
Wei Wang ◽  
Lina Liu ◽  
Yajuan Jiang ◽  
Zhimei Niu ◽  
...  
Keyword(s):  
Inner Mongolia ◽  
Surface Sediments ◽  
Qaidam Basin ◽  
Source Area ◽  
Soil Surface ◽  
Mean Annual Precipitation ◽  
Climate Reconstructions ◽  
Moisture Conditions ◽  
Semi Arid ◽  
Inner Mongolia Plateau

The reliability of the ratio between Artemisia and Chenopodiaceae pollen percentage (i.e. A/ C) in differentiating vegetation and reflecting moisture conditions in arid and semi-arid regions has been disputed and this hindered its potential application in palaeoclimate reconstructions. In this paper, we investigated the A/ C ratios of lake-centre surface sediment from 45 lakes in the Inner Mongolia Plateau and the Qaidam Basin in arid and semi-arid China, and numerically studied the relationships of A/ C ratios with vegetation and moisture. We found that the A/ C ratio of lake-centre surface sediments can be used as an effective index to differentiate desert and steppe and also can be used as a valid indicator to infer mean annual precipitation (MAP) in the Inner Mongolia Plateau and the Qaidam Basin in arid and semi-arid China. Moreover, the A/ C ratio from lake-centre surface sediments is more reliable and robust than that of soil-surface samples in differentiating vegetation and reflecting moisture conditions, and this might be attributed to its larger pollen source area and regional representation. In addition, the ( A − C)/( A + C) index helps to overcome the inherent weakness of non-linearity of the A/ C ratio and may be useful in paleo-vegetation reconstruction. These findings provide useful references for pollen-based vegetation and climate reconstructions of lake cores in arid and semi-arid China.

The role of landscape morphology on soil moisture variability in semi‐arid ecosystems

2020 ◽  
Author(s):  
Ankur Srivastava ◽  
Patricia M. Saco ◽  
Jose F. Rodriguez ◽  
Nikul Kumari ◽  
Kwok Pan Chun ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Arid Ecosystems ◽  
Landscape Morphology ◽  
Soil Moisture Variability ◽  
Semi Arid ◽  
Moisture Variability
Sign in / Sign up

Export Citation Format

Share Document