Modelling the transfer of pesticide transformation products from agricultural fields to the aquatic environment – state of knowledge and future challenges

2020 ◽  
Author(s):  
Matthias Gassmann
Keyword(s):  
Aquatic Environment ◽  
Prediction Models ◽  
Environmental Fate ◽  
Transformation Products ◽  
Model Complexity ◽  
Agricultural Fields ◽  
Catchment Scale ◽  
Pathway Prediction ◽  
Scale Models ◽  
Leaching Models

<p>Transformation products (TP) of pesticides are found everywhere in the aquatic environment. Their dynamic formation and subsequent transport from agricultural fields to adjacent water bodies can be estimated by using environmental fate models, which is done e.g. in the registration process for plant protection products in the European Union. In this study, an overview of models, transformation simulation concepts and model applications for TP estimation including leaching and catchment scale models is given. The review is restricted to models which were tested against field data in peer-reviewed publications. The models included in this review are GLEAMS, MACRO, RZWQM(2), PEARL, PRZM, Pelmo, LEACHM, HYDRUS 1-D, ZIN-AgriTra and the Field Release Model (FRM).</p><p>Investigating model structures revealed, that six transformation schemes, i.e. possible transformation pathways, are implemented in the models. Only one of the reviewed models, PELMO, uses a completely flexible scheme. In all other models, pathways are restricted. An assessment of model complexity, including hydrological processes and transformation-affecting processes, resulted in PELMO having the highest transformation but the least hydrological complexity among leaching models. RZWQM is the leaching model with the highest hydrological complexity and ranks second in transformation processes. Among the three catchment scale models, ZIN-AgriTra ranks highest in both, hydrological and transformation complexity.</p><p>Even though the number of publications of TP model applications is rather low, the number of leaching models is adequate (eight models). At the catchment scale, however, only two models with proven applications exist in the literature. A spatio-temporal analysis of all models revealed a gap in catchment and regional-scale models with a daily or lower temporal resolution. Thus, well-developed and applied catchment-scale models should be extended by a TP module. This would enable scientists and authorities to estimate TP concentrations or to analyse the environmental fate of TPs at the larger catchment scale. At the same time, the fate processes in models should be updated to reflect the current state of knowledge, especially more flexible transformation schemes and the formation of TPs in different compartments (i.e. plant, soil, water). The integration of pathway prediction models such as the University of Minnesota Pathway Prediction System could enhance the assessment of the large number of pesticide TPs in the aquatic environment.</p>

scholarly journals Modelling the Fate of Pesticide Transformation Products From Plot to Catchment Scale—State of Knowledge and Future Challenges

2021 ◽  
Vol 9 ◽  
Author(s):  
Matthias Gassmann
Keyword(s):  
Preferential Flow ◽  
Prediction Models ◽  
Environmental Fate ◽  
Plant Protection ◽  
Formation Rate ◽  
Regional Scale ◽  
Parent Compound ◽  
Transformation Products ◽  
Model Complexity ◽  
Catchment Scale

Transformation products (TP) of pesticides are found everywhere in the aquatic environment. Their dynamic formation and subsequent transport from agricultural fields to adjacent water bodies can be estimated by using environmental fate models, which is done in the registration process for plant protection products in the European Union. In this study, peer-reviewed applications of such models, the model complexity and their structure are documented and analysed. In total, 20 publications of 10 models – eight leaching models (GLEAMS, MACRO, RZWQM2, PEARL, PRZM, Pelmo, LEACHM, HYDRUS 1-D) and two catchment scale models (Zin-AgriTra, FRM) – were identified. The reviewed models greatly differ in their process complexity regarding the formation rate and the formation pathways of TPs.The major reason given for models failing to reproduce sampled TP concentrations in case studies was an erroneous substance transport, especially missing preferential flow simulation in soil. However, the contribution of TP formation processes to simulation uncertainty was not analysed at all in most of the studies. By comparing the structure of existing models, the state of knowledge on TP fate and requirements of TP fate assessment, the following recommendations were drawn: i) It is suggested that the models should be updated to reflect the current state of knowledge in process research, especially more complex transformation schemes and the formation of different TPs in different compartments, which was not included in most of the models. ii) Even though there are pesticide parent compound fate models at the catchment scale with a temporal resolution of one day, none of these models is able to simulate TP fate. Such models would enable scientists and authorities to estimate the environmental fate of TPs at the larger catchment scale or the regional scale. iii) To get over the assessment of the huge number of TPs formed in the environment, an integration of Quantitative Structure Properties Relationship models predicting TP fate characteristics, TP pathway prediction models and environmental fate models is suggested. This would allow for a largely automated and comprehensive assessment of the fate of a pesticide parent compound and all its TPs for regulatory purposes.

scholarly journals Short period forecasting of catchment-scale precipitation. Part I: the role of Numerical Weather Prediction

2000 ◽  
Vol 4 (4) ◽  
pp. 627-633 ◽  
Author(s):  
M. A. Pedder ◽  
M. Haile ◽  
A. J. Thorpe
Keyword(s):  
Numerical Weather Prediction ◽  
Balance Equation ◽  
Prediction Models ◽  
Weather Prediction ◽  
Phase Changes ◽  
Scale Model ◽  
Catchment Scale ◽  
Numerical Weather ◽  
Short Period ◽  
Moisture Balance

Abstract. A deterministic forecast of surface precipitation involves solving a time-dependent moisture balance equation satisfying conservation of total water substance. A realistic solution needs to take into account feedback between atmospheric dynamics and the diabatic sources of heat energy associated with phase changes, as well as complex microphysical processes controlling the conversion between cloud water (or ice) and precipitation. Such processes are taken into account either explicitly or via physical parameterisation schemes in many operational numerical weather prediction models; these can therefore generate precipitation forecasts which are fully consistent with the predicted evolution of the atmospheric state as measured by observations of temperature, wind, pressure and humidity. This paper reviews briefly the atmospheric moisture balance equation and how it may be solved in practice. Solutions are obtained using the Meteorological Office Mesoscale version of its operational Unified Numerical Weather Prediction (NWP) model; they verify predicted precipitation rates against catchment-scale values based on observations collected during an Intensive Observation Period (IOP) of HYREX. Results highlight some limitations of an operational NWP forecast in providing adequate time and space resolution, and its sensitivity to initial conditions. The large-scale model forecast can, nevertheless, provide important information about the moist dynamical environment which could be incorporated usefully into a higher resolution, ‘storm-resolving’ prediction scheme. Keywords: Precipitation forecasting; moisture budget; numerical weather prediction

The environmental fate of graphene oxide in aquatic environment—Complete mitigation of its acute toxicity to planktonic and benthic crustaceans by algae

2020 ◽  
Vol 399 ◽  
pp. 123027 ◽  
Author(s):  
Tomáš Malina ◽  
Eliška Maršálková ◽  
Kateřina Holá ◽  
Radek Zbořil ◽  
Blahoslav Maršálek
Keyword(s):  
Graphene Oxide ◽  
Acute Toxicity ◽  
Aquatic Environment ◽  
Environmental Fate

scholarly journals Variation-Oriented Data Filtering for Improvement in Model Complexity of Air Pollutant Prediction Model

2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
Chi Man Vong ◽  
Weng Fai Ip ◽  
Pak Kin Wong
Keyword(s):  
Prediction Model ◽  
Air Pollutants ◽  
Prediction Models ◽  
Air Pollutant ◽  
Accurate Prediction ◽  
Model Complexity ◽  
Support Vector ◽  
Discrete Wavelet ◽  
Training Time ◽  
Model Size

Accurate prediction models for air pollutants are crucial for forecast and health alarm to local inhabitants. In recent literature,discrete wavelet transform(DWT) was employed to decompose a series of air pollutant levels, followed by modeling usingsupport vector machine(SVM). This combination of DWT and SVM was reported to produce a more accurate prediction model for air pollutants by investigating different levels of frequency bands. However, DWT has a significant demand in model complexity, namely, the training time and the model size of the prediction model. In this paper, a new method calledvariation-oriented filtering(VF) is proposed to remove the data with low variation, which can be considered asnoiseto a prediction model. By VF, the noise and the size of the series of air pollutant levels can be reduced simultaneously and hence so are the training time and model size. The SO2(sulfur dioxide) level in Macau was selected as a test case. Experimental results show that VF can effectively and efficiently reduce the model complexity with improvement in predictive accuracy.

scholarly journals Bonded Concrete Overlays: A Brief Discussion on Restrained Shrinkage Deformations and Their Prediction Models

2019 ◽  
Vol 61 (2) ◽  
pp. 107-129
Author(s):  
Wojciech Cyron ◽  
Martin Nilsson ◽  
Mats Emborg ◽  
Ulf Ohlsson
Keyword(s):  
Prediction Models ◽  
Asphalt Pavement ◽  
Theoretical Explanation ◽  
Empirical Equations ◽  
Restrained Shrinkage ◽  
Micro Scale ◽  
Concrete Overlays ◽  
The Past ◽  
Scale Models ◽  
Thermal Dilation

Abstract Bonded concrete overlays (BCO) on bridge decks are beneficial solutions due to their superior properties as compared to the typical asphalt pavement. A significant number of overlays suffer however, from occurrence of cracks and delamination due to poor bond, and restrained shrinkage and thermal dilation. Over the past years different appraisals for estimation of the restrained deformations have been developed, from micro-scale models, based on poromechanics, to empirical equations as given in B3 or B4 models suggested by Bažant. This paper provides a short overview of calculation models along with a brief theoretical explanation of shrinkage mechanism.

A catchment-based approach to recharge estimation in the Liverpool Plains, NSW, Australia

2006 ◽  
Vol 57 (3) ◽  
pp. 309 ◽  
Author(s):  
H. Sun ◽  
P. S. Cornish
Keyword(s):  
Land Use ◽  
Assessment Tool ◽  
Shallow Groundwater ◽  
Land Uses ◽  
Point Scale ◽  
Catchment Scale ◽  
Crop Models ◽  
Scale Models ◽  
Catchment Model ◽  
Catchment Runoff

This study investigated drainage and shallow groundwater change in a headwater catchment of the Liverpool Plains in north-western New South Wales. A catchment model, SWAT (Soil and Water Assessment Tool), was used to explore rain-fed drainage to shallow groundwater and its relationship to land use. Drainage was predicted along with the prediction of runoff on a catchment and land-use basis over a simulation period of 44 years. Predicted drainage in the catchment was 8 mm/year for the 44 years, which essentially matched estimates derived from bore data observed in the catchment over a 22-year period. These estimates of drainage are much lower than published estimates based on scaling up to the catchment using estimates of drainage derived from point-scale models for different land uses. Estimates of drainage for the different land uses, derived from the catchment model, were also generally lower than simulated drainages from other studies in the area using point-scale models. The investigation demonstrates a place for catchment-based modelling for estimating drainage at the catchment scale. This is mainly because observed catchment runoff is used as an error controller in catchment recharge modelling, whereas scaled-up point-scale modelling generally does not use observed catchment runoff to derive the catchment drainage. Modelling on the Liverpool Plains catchment also suggests that some of the drainage entering the vadose zone and groundwater is later lost via evapotranspiration, a process not generally simulated in crop models, and requiring further investigation to improve understanding of recharge processes and accuracy of modelling.

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