Linking regional modelling with field measurements to evaluate effectiveness of living windbreaks as measures against wind erosion

2020 ◽  
Author(s):  
Thomas Weninger ◽  
Nathan King ◽  
Karl Gartner ◽  
Barbara Kitzler ◽  
Simon Scheper ◽  
...  
Keyword(s):  
Soil Loss ◽  
Wind Erosion ◽  
Regional Scale ◽  
Regional Distribution ◽  
Sediment Traps ◽  
Agricultural Landscapes ◽  
Spatial And Temporal Variability ◽  
Vegetation Density ◽  
Regional Modelling ◽  
Ground Truth Data

<p>The degrading impact of wind on agricultural soils has been observed throughout centuries in the Pannonian region of central Europe. Nevertheless, soil loss was not yet quantified and the extent or relevance of the problem are unknown for this agriculturally important region. Especially dry soil surface is highly prone to erosion and as drought periods are expected to become more frequent and severe with changing climate, the risk of wind erosion will increase accordingly. Living windbreaks and similar agro-forestry systems are supposed to be highly effective measures against wind erosion. In an extensive research project, multiple approaches are integrated to obtain a broad view onto the relevance of soil degradation by wind on plot scale and its regional distribution.</p><p>More in detail, case studies are conducted where the soil loss by wind erosion is measured in sediment traps. Data about driving and stabilizing factors like wind speed, soil moisture, vegetation density etc. are measured in high spatial and temporal resolution. The measurements started in December 2019. Besides, wind erosion risk is modelled and mapped on regional scale applying state-of-the-art model procedures. The measurement results are used in an attempt to down-scale the model application and thus create a link to ground-truth data. Information about spatial and temporal variability of the driving factors is used for implementation of stochastic calculation procedures in a sensitivity study which determines the most relevant factors for wind erosion mitigation.</p><p>The used modelling approach also includes the effects of wind shelters what enables a partly evaluation of the existing network of such elements in the Pannonian region. There, the Authority of Land Reform has been supporting and documenting the installation of wind shelters for more than 60 years. Incorporating this data base, quantitative and qualitative statements will be developed about the state of the shelter belts and their relevance concerning erosion rates. Additionally, the potential and actual value of living windbreaks will be determined with special regards to physiological and ecological characteristics, stability under future climate conditions and further ecosystem services in agricultural landscapes.</p>

Spatio-temporal effects of vegetated windbreaks on wind erosion and microclimate as basis for model development

2021 ◽  
Author(s):  
Thomas Weninger ◽  
Simon Scheper ◽  
Nathan King ◽  
Karl Gartner ◽  
Barbara Kitzler ◽  
...  
Keyword(s):  
Soil Water ◽  
Wind Erosion ◽  
Arable Land ◽  
Model Development ◽  
Weather Conditions ◽  
Bare Soil ◽  
Sediment Traps ◽  
Spatial And Temporal Variability ◽  
Regional Modelling ◽  
Erosion Rates

<p>Wind erosion of arable soil is considered a risk factor for Austrian fields, but direct measurements of soil loss are not available until now. Despite this uncertainty, vegetated windbreaks have been established to minimize adverse wind impacts on arable land. The study addresses these questions: i) How relevant is wind erosion as a factor of soil degradation? ii) How important is the protective effect of vegetated windbreaks? iii) Are systematic patterns of spatial and temporal variability of wind erosion rates detectable in response to weather conditions? </p><p>Two experimental fields adjacent to windbreaks were equipped with sediment traps, soil moisture sensors, and meteorological measurement equipment for microclimatic patterns. Sediment traps were arranged in high spatial resolution from next to the windbreak to a distance of ten times the windbreak height. Beginning in January 2020, the amount of trapped sediment was analyzed every three weeks. The highest wind erosion rates on bare soil were observed in June and July. For unprotected fields with bare soil, upscaled annual erosion rates were as high as 0.8 tons per hectare, and sediment trapped increased in a linear fashion with distance from the windbreak. Soil water content near the surface (5 cm depth) was three percent higher at a distance of two times the height of the windbreak than at a distance of six times the height. For the same respective distances from the windbreak, we observed 29 days of soil water contents below the wilting point compared with 60 days.</p><p>The preliminary outcomes confirmed the expected effects of windbreaks on soil erosion and microclimate in agricultural fields. Prospective results from multiple vegetation periods will be used in an upscaling approach to gain informations for the whole basin. That is meant to be done by a combination with a soil wind erosion model which was so far used for regional modelling of wind erosion susceptibility.</p>

Regional coupling between chest wall and lung expansion during HFV: a positron imaging study

1993 ◽  
Vol 74 (5) ◽  
pp. 2242-2252 ◽  
Author(s):  
J. G. Venegas ◽  
K. Tsuzaki ◽  
B. J. Fox ◽  
B. A. Simon ◽  
C. A. Hales
Keyword(s):  
Chest Wall ◽  
Lung Volume ◽  
Gas Transport ◽  
Regional Scale ◽  
Regional Distribution ◽  
Imaging Study ◽  
High Frequency Ventilation ◽  
Rib Cage ◽  
Lung Expansion ◽  
Frequency Ventilation

Apparently conflicting differences between the regional chest wall motion and gas transport have been observed during high-frequency ventilation (HFV). To elucidate the mechanism responsible for such differences, a positron imaging technique capable of assessing dynamic chest wall volumetric expansion, regional lung volume, and regional gas transport was developed. Anesthetized supine dogs were studied at ventilatory frequencies (f) ranging from 1 to 15 Hz and eucapnic tidal volumes. The regional distribution of mean lung volume was found to be independent of f, but the apex-to-base ratio of regional chest wall expansion favored the lung bases at low f and became more homogeneous at higher f. Regional gas transport per unit of lung volume, assessed from washout maneuvers, was homogeneous at 1 Hz, favored the bases progressively as f increased to 9 Hz, and returned to homogeneity at 15 Hz. Interregional asynchrony (pendelluft) and right-to-left differences were small at this large regional scale. Analysis of the data at a higher spatial resolution showed that the motion of the diaphragm relative to the excursions of the rib cage decreased as f increased. These differences from apex to base in regional chest wall expansion and gas transport were consistent with a simple model including lung, rib cage, and diaphragm regional impedances and a viscous coupling between lungs and chest wall caused by the relative sliding between pleural surfaces. To further test this model, we studied five additional animals under open chest conditions. These studies resulted in a homogeneous and f-independent regional gas transport. We conclude that the apex-to-base distribution of gas transport observed during HFV is not caused by intrinsic lung heterogeneity but rather is a result of chest wall expansion dynamics and its coupling to the lung.

A Simulation Model of Daily Wind Erosion Soil Loss

1983 ◽  
Vol 26 (6) ◽  
pp. 1758-1765 ◽  
Author(s):  
George W. Cole ◽  
Leon Lyles ◽  
Lawrence J. Hagen
Keyword(s):  
Simulation Model ◽  
Soil Loss ◽  
Wind Erosion

scholarly journals Sources of black carbon aerosols in South Asia and surrounding regions during the Integrated Campaign for Aerosols, Gases and Radiation Budget (ICARB)

2015 ◽  
Vol 15 (10) ◽  
pp. 5415-5428 ◽  
Author(s):  
R. Kumar ◽  
M. C. Barth ◽  
V. S. Nair ◽  
G. G. Pfister ◽  
S. Suresh Babu ◽  
...  
Keyword(s):  
Spatial Variability ◽  
South Asia ◽  
Black Carbon ◽  
Biomass Burning ◽  
Regional Scale ◽  
Anthropogenic Sources ◽  
Radiation Budget ◽  
Anthropogenic Emissions ◽  
Spatial And Temporal Variability ◽  
Mass Concentrations

Abstract. This study examines differences in the surface black carbon (BC) aerosol loading between the Bay of Bengal (BoB) and the Arabian Sea (AS) and identifies dominant sources of BC in South Asia and surrounding regions during March–May 2006 (Integrated Campaign for Aerosols, Gases and Radiation Budget, ICARB) period. A total of 13 BC tracers are introduced in the Weather Research and Forecasting Model coupled with Chemistry to address these objectives. The model reproduced the temporal and spatial variability of BC distribution observed over the AS and the BoB during the ICARB ship cruise and captured spatial variability at the inland sites. In general, the model underestimates the observed BC mass concentrations. However, the model–observation discrepancy in this study is smaller compared to previous studies. Model results show that ICARB measurements were fairly well representative of the AS and the BoB during the pre-monsoon season. Elevated BC mass concentrations in the BoB are due to 5 times stronger influence of anthropogenic emissions on the BoB compared to the AS. Biomass burning in Burma also affects the BoB much more strongly than the AS. Results show that anthropogenic and biomass burning emissions, respectively, accounted for 60 and 37% of the average ± standard deviation (representing spatial and temporal variability) BC mass concentration (1341 ± 2353 ng m−3) in South Asia. BC emissions from residential (61%) and industrial (23%) sectors are the major anthropogenic sources, except in the Himalayas where vehicular emissions dominate. We find that regional-scale transport of anthropogenic emissions contributes up to 25% of BC mass concentrations in western and eastern India, suggesting that surface BC mass concentrations cannot be linked directly to the local emissions in different regions of South Asia.

scholarly journals Sonic anemometry and sediment traps to evaluate the effectiveness of windbreaks in preventing wind erosion

2017 ◽  
Vol 74 (6) ◽  
pp. 425-435 ◽  
Author(s):  
Alejandro López ◽  
Diego Luis Valera ◽  
Francisco Domingo Molina-Aiz ◽  
Francisco Javier Lozano ◽  
Carlos Asensio
Keyword(s):  
Wind Erosion ◽  
Sediment Traps

scholarly journals Inferring <sup>222</sup>Rn soil fluxes from ambient <sup>222</sup>Rn activity and eddy covariance measurements of CO<sub>2</sub>

2016 ◽  
Vol 9 (11) ◽  
pp. 5523-5533 ◽  
Author(s):  
Sander van der Laan ◽  
Swagath Manohar ◽  
Alex Vermeulen ◽  
Fred Bosveld ◽  
Harro Meijer ◽  
...  
Keyword(s):  
Eddy Covariance ◽  
Activity Concentration ◽  
Regional Scale ◽  
Surface Flux ◽  
Surface Fluxes ◽  
Spatial And Temporal Variability ◽  
Single Pair ◽  
The South ◽  
Practical Applications ◽  
Soil Flux

Abstract. We present a new methodology, which we call Single Pair of Observations Technique with Eddy Covariance (SPOT-EC), to estimate regional-scale surface fluxes of 222Rn from tower-based observations of 222Rn activity concentration, CO2 mole fractions and direct CO2 flux measurements from eddy covariance. For specific events, the regional (222Rn) surface flux is calculated from short-term changes in ambient (222Rn) activity concentration scaled by the ratio of the mean CO2 surface flux for the specific event to the change in its observed mole fraction. The resulting 222Rn surface emissions are integrated in time (between the moment of observation and the last prior background levels) and space (i.e. over the footprint of the observations). The measurement uncertainty obtained is about ±15 % for diurnal events and about ±10 % for longer-term (e.g. seasonal or annual) means. The method does not provide continuous observations, but reliable daily averages can be obtained. We applied our method to in situ observations from two sites in the Netherlands: Cabauw station (CBW) and Lutjewad station (LUT). For LUT, which is an intensive agricultural site, we estimated a mean 222Rn surface flux of (0.29 ± 0.02) atoms cm−2 s−1 with values  > 0.5 atoms cm−2 s−1 to the south and south-east. For CBW we estimated a mean 222Rn surface flux of (0.63 ± 0.04) atoms cm−2 s−1. The highest values were observed to the south-west, where the soil type is mainly river clay. For both stations good agreement was found between our results and those from measurements with soil chambers and two recently published 222Rn soil flux maps for Europe. At both sites, large spatial and temporal variability of 222Rn surface fluxes were observed which would be impractical to measure with a soil chamber. SPOT-EC, therefore, offers an important new tool for estimating regional-scale 222Rn surface fluxes. Practical applications furthermore include calibration of process-based 222Rn soil flux models, validation of atmospheric transport models and performing regional-scale inversions, e.g. of greenhouse gases via the SPOT 222Rn-tracer method.

scholarly journals Comparison of the Spatial Wind Erosion Patterns of Erosion Risk Mapping and Quantitative Modeling in Eastern Austria

Land ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 974
Author(s):  
Simon Scheper ◽  
Thomas Weninger ◽  
Barbara Kitzler ◽  
Lenka Lackóová ◽  
Wim Cornelis ◽  
...  
Keyword(s):  
Soil Loss ◽  
Wind Erosion ◽  
Large Scale ◽  
Pannonian Basin ◽  
Target Area ◽  
Erosion Risk ◽  
Additional Information ◽  
Weather Factor ◽  
Not At Risk ◽  
Erosion Equation

Various large-scale risk maps show that the eastern part of Austria, in particular the Pannonian Basin, is one of the regions in Europe most vulnerable to wind erosion. However, comprehensive assessments of the severity and the extent of wind erosion risk are still lacking for this region. This study aimed to prove the results of large-scale maps by developing high-resolution maps of wind erosion risk for the target area. For this, we applied a qualitative soil erosion assessment (DIN 19706) with lower data requirements and a more data-demanding revised wind erosion equation (RWEQ) within a GIS application to evaluate the process of assessing wind erosion risk. Both models defined similar risk areas, although the assignment of severity classes differed. Most agricultural fields in the study area were classified as not at risk to wind erosion (DIN 19706), whereas the mean annual soil loss rate modeled by RWEQ was 3.7 t ha−1 yr−1. August was the month with the highest modeled soil loss (average of 0.49 t ha−1 month−1), due to a low percentage of vegetation cover and a relatively high weather factor combining wind speed and soil moisture effects. Based on the results, DIN 19706 is suitable for a general classification of wind erosion-prone areas, while RWEQ can derive additional information such as seasonal distribution and soil loss rates besides the spatial extents of wind erosion.

scholarly journals Multiscale observations of NH<sub>3</sub> around Toronto, Canada

2021 ◽  
Vol 14 (2) ◽  
pp. 905-921
Author(s):  
Shoma Yamanouchi ◽  
Camille Viatte ◽  
Kimberly Strong ◽  
Erik Lutsch ◽  
Dylan B. A. Jones ◽  
...  
Keyword(s):  
Temporal Variability ◽  
Grid Point ◽  
Regional Scale ◽  
Model Performance ◽  
In Situ Measurements ◽  
Coefficient Of Determination ◽  
Spatial And Temporal Variability ◽  
Predictive Capacity ◽  
Total Column

Abstract. Ammonia (NH3) is a major source of nitrates in the atmosphere and a major source of fine particulate matter. As such, there have been increasing efforts to measure the atmospheric abundance of NH3 and its spatial and temporal variability. In this study, long-term measurements of NH3 derived from multiscale datasets are examined. These NH3 datasets include 16 years of total column measurements using Fourier transform infrared (FTIR) spectroscopy, 3 years of surface in situ measurements, and 10 years of total column measurements from the Infrared Atmospheric Sounding Interferometer (IASI). The datasets were used to quantify NH3 temporal variability over Toronto, Canada. The multiscale datasets were also compared to assess the representativeness of the FTIR measurements. All three time series showed positive trends in NH3 over Toronto: 3.34 ± 0.89 %/yr from 2002 to 2018 in the FTIR columns, 8.88 ± 5.08 %/yr from 2013 to 2017 in the surface in situ data, and 8.38 ± 1.54 %/yr from 2008 to 2018 in the IASI columns. To assess the representative scale of the FTIR NH3 columns, correlations between the datasets were examined. The best correlation between FTIR and IASI was obtained with coincidence criteria of ≤25 km and ≤20 min, with r=0.73 and a slope of 1.14 ± 0.06. Additionally, FTIR column and in situ measurements were standardized and correlated. Comparison of 24 d averages and monthly averages resulted in correlation coefficients of r=0.72 and r=0.75, respectively, although correlation without averaging to reduce high-frequency variability led to a poorer correlation, with r=0.39. The GEOS-Chem model, run at 2∘ × 2.5∘ resolution, was compared to FTIR and IASI to assess model performance and investigate the correlation of observational data and model output, both with local column measurements (FTIR) and measurements on a regional scale (IASI). Comparisons on a regional scale (a domain spanning 35 to 53∘ N and 93.75 to 63.75∘ W) resulted in r=0.57 and thus a coefficient of determination, which is indicative of the predictive capacity of the model, of r2=0.33, but comparing a single model grid point against the FTIR resulted in a poorer correlation, with r2=0.13, indicating that a finer spatial resolution is needed for modeling NH3.

On the simulation of regional scale sublimation over boreal and agricultural landscapes in a climate model

2006 ◽  
Vol 44 (3) ◽  
pp. 289-304 ◽  
Author(s):  
Murray D. MacKay ◽  
Paul A. Bartlett ◽  
Ed Chan ◽  
Chris Derksen ◽  
Song Guo ◽  
...  
Keyword(s):  
Climate Model ◽  
Regional Scale ◽  
Agricultural Landscapes

scholarly journals Comparing two years of Saharan dust source activation obtained by regional modelling and satellite observations

2013 ◽  
Vol 13 (5) ◽  
pp. 2381-2390 ◽  
Author(s):  
I. Tegen ◽  
K. Schepanski ◽  
B. Heinold
Keyword(s):  
Regional Scale ◽  
Dust Emission ◽  
Saharan Dust ◽  
Strong Increase ◽  
Regional Modelling ◽  
Dust Source ◽  
Low Level ◽  
Mountainous Regions ◽  
Low Level Jets ◽  
The Difference

Abstract. A regional-scale dust model is used to simulate Saharan dust emissions and atmospheric distributions in the years 2007 and 2008. The model results are compared to dust source activation events compiled from infrared dust index imagery from the geostationary Meteosat Second Generation (MSG) satellite. The observed morning maximum in dust source activation frequencies indicates that the breakdown of nocturnal low level jets is an important mechanism for dust source activation in the Sahara. The comparison shows that the time of the day of the onset of dust emission is delayed in the model compared to the observations. Also, the simulated number of dust emission events associated with nocturnal low level jets in mountainous regions is underestimated in the model. The MSG dust index observations indicate a strong increase in dust source activation frequencies in the year 2008 compared to 2007. The difference between the two years is less pronounced in the model. Observations of dust optical thickness, e.g. at stations of the sunphotometer network AERONET, do not show such increase, in agreement with the model results. This indicates that the number of observed dust activation events is only of limited use for estimating actual dust emission fluxes in the Sahara. The ability to reproduce interannual variability of Saharan dust with models remains an important challenge for understanding the controls of the atmospheric dust load.

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