scholarly journals Simplified Interception/Evaporation Model

Hydrology ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 99
Author(s):  
Giorgio Baiamonte
Keyword(s):  
Cover Crop ◽  
Large Scale ◽  
Event Scale ◽  
Storage Model ◽  
Evaporation Model ◽  
Simplified Approach ◽  
Continuous Simulation ◽  
Dry Spells ◽  
Hourly Rainfall ◽  
Power Law Equation

It is known that at the event scale, evaporation losses of rainfall intercepted by canopy are a few millimeters, which is often not much in comparison to other stocks in the water balance. Nevertheless, at yearly scale, the number of times that the canopy is filled by rainfall and then depleted can be so large that the interception flux may become an important fraction of rainfall. Many accurate interception models and models that describe evaporation by wet canopy have been proposed. However, they often require parameters that are difficult to obtain, especially for large-scale applications. In this paper, a simplified interception/evaporation model is proposed, which considers a modified Merrian model to compute interception during wet spells, and a simple power-law equation to model evaporation by wet canopy during dry spells. Thus, the model can be applied for continuous simulation, according to the sub hourly rainfall data that is appropriate to study both processes. It is shown that the Merrian model can be derived according to a simple linear storage model, also accounting for the antecedent intercepted stored volume, which is useful to consider for the suggested simplified approach. For faba bean cover crop, an application of the suggested procedure, providing reasonable results, is performed and discussed.

scholarly journals DREAM: a distributed model for runoff, evapotranspiration, and antecedent soil moisture simulation

2005 ◽  
Vol 2 ◽  
pp. 31-39 ◽  
Author(s):  
S. Manfreda ◽  
M. Fiorentino ◽  
V. Iacobellis
Keyword(s):  
Soil Moisture ◽  
Distributed Model ◽  
Distributed Hydrological Model ◽  
Antecedent Soil Moisture ◽  
Event Scale ◽  
Continuous Simulation ◽  
Proposed Model ◽  
Hourly Rainfall ◽  
Physically Based ◽  
Daily Water

Abstract. The paper introduces a semi-distributed hydrological model, suitable for continuous simulations, based upon the use of daily and hourly time steps. The model is called Distributed model for Runoff, Evapotranspiration, and Antecedent soil Moisture simulation (DREAM). It includes a daily water budget and an "event scale" hourly rainfall-runoff module. The two modules may be used separately or in cascade for continuous simulation. The main advantages of this approach lay in the robust and physically based parameterization, which allows use of prior information and measurable data for parameter estimation. The proposed model was applied over four medium-sized basins in southern Italy, exhibiting considerable differences in climate and other physical characteristics. The capabilities of the two modules (daily and hourly) and of the combined runs were tested against measured data.

A Simplified Protocol for the ortho-Deuteration of Acidic Aromatic Compounds in D2O

2019 ◽  
Author(s):  
Alyssa Garreau ◽  
Hanyang Zhou ◽  
Michael Young
Keyword(s):  
Carboxylic Acid ◽  
Aromatic Compounds ◽  
Large Scale ◽  
Simplified Approach ◽  
Directing Group ◽  
Large Scale Synthesis

<div>Methods to catalytically introduce deuterium in synthetically useful yields ortho to a carboxylic acid directing group on arenes typically requires D2 or CD3CO2D, which makes using these approaches cost prohibitive for large scale synthesis (equipment and reagent costs respectively). Herein we present a simplified approach using catalytic RhIII and D2O as deuterium source, and show its application to H/D exchange on various acidic substrates.</div>

A Simplified Protocol for the ortho-Deuteration of Acidic Aromatic Compounds in D2O

2019 ◽  
Author(s):  
Alyssa Garreau ◽  
Hanyang Zhou ◽  
Michael Young
Keyword(s):  
Carboxylic Acid ◽  
Aromatic Compounds ◽  
Large Scale ◽  
Simplified Approach ◽  
Directing Group ◽  
Large Scale Synthesis

<div>Methods to catalytically introduce deuterium in synthetically useful yields ortho to a carboxylic acid directing group on arenes typically requires D2 or CD3CO2D, which makes using these approaches cost prohibitive for large scale synthesis (equipment and reagent costs respectively). Herein we present a simplified approach using catalytic RhIII and D2O as deuterium source, and show its application to H/D exchange on various acidic substrates.</div>

Dynamic Experimental Investigation on the Self-Vibration Characteristics of Liquid Storage Tanks Under Seismic Excitations

2013 ◽  
Author(s):  
Zhou Fang ◽  
Zhiping Chen ◽  
Guodong Jia ◽  
Hui Wang ◽  
Xiang Li
Keyword(s):  
Large Scale ◽  
Vibration Characteristics ◽  
The Self ◽  
Earthquake Simulation ◽  
Seismic Excitations ◽  
Storage Model ◽  
Design Standard ◽  
Finite Element Software ◽  
Liquid Storage ◽  
Cylindrical Steel

A large-scale earthquake simulation experiment about the unanchored cylindrical steel liquid storage model tanks has been completed. The self-vibration characteristics of the model tanks with liquid inside were investigated based on the experimental data of the acceleration dynamic response. The seismic table test, the analysis methods are designed and conducted, and experimental results of the model tanks were carefully measured. Furthermore, ANSYS finite element software was used to simulate and calculate the low order natural frequency and fundamental frequency of the model tank systems according to the national design standard. The reasons for the existence of consistency and differences among the results obtained from experiments, numerical simulation and national design standard were discussed.

Development of One Dimensional Numerical Model on Large Water Diversion System

2015 ◽  
Vol 744-746 ◽  
pp. 1062-1065
Author(s):  
Cheng Zhang ◽  
Lin Zha
Keyword(s):  
Numerical Model ◽  
Boundary Conditions ◽  
Water Level ◽  
Large Scale ◽  
Water Diversion ◽  
One Dimensional ◽  
Continuous Simulation ◽  
North Water ◽  
Flow Transitions ◽  
Parallel Connections

A one-dimensional numerical model was developed for unsteady-flow in a large-scale conveyance channel with complex inner boundary conditions. Using Taylor expansion and finite difference method, this model incorporated three types of inner boundary conditions, including regulators, inverted siphons, and flumes with parallel connections. It can facilitate continuous simulation with large-amplitude variations in water level and flow discharge during the flow transitions. Transition flows were simulated by this model, which were caused by the operation of a single gate of the Middle Route of the South-to-North Water Diversion Project. The discharges of simulation were consistent with the discharges of formulas calculation, and the water level variations accords with hydraulic law. The results indicate its efficiency and applicability on simulating hydraulic response of large-scale conveyance channels with complex inner boundary conditions.

scholarly journals Country-wide CML rainfall estimation and CML-Radar combination in Germany

2021 ◽  
Author(s):  
Christian Chwala ◽  
Tanja Winterrath ◽  
Maximilian Graf ◽  
Julius Polz ◽  
Harald Kunstmann
Keyword(s):  
Large Scale ◽  
Rain Event ◽  
Rainfall Estimation ◽  
Radar Rainfall ◽  
Rain Gauges ◽  
Large Scale Analysis ◽  
Seasonal And Diurnal Variations ◽  
Hourly Rainfall ◽  
First Results ◽  
Microwave Link

&lt;p&gt;Commercial microwave links (CMLs) have emerged as a valuable source of rainfall information that can complement existing observations. In Germany, we acquire attenuation data from 4000 CMLs with a temporal resolution of one minute. In this contribution we present our results of deriving country-wide rainfall information from these CML data and show the first long-term application of CML data for adjusting the radar rainfall field.&lt;/p&gt;&lt;p&gt;We present results of a large-scale analysis of our country-wide dataset for one full year (Graf et al. 2020) and compare it with the gauge adjusted radar product RADOLAN-RW from the German Weather Service and the climatologically corrected radar product RADKLIM-YW. Our analysis also compares several different methods for processing CML data, including our recent improvements for the separation of dry and rainy periods in noisy CML attenuation time series based on a convolutional neural network (Polz et al. 2020). We show seasonal and diurnal variations of the performance of CML-derived rainfall data. Promising results are achieved year-round except for periods with solid precipitation. Pearson correlations for the comparison of the hourly rainfall sums reach up to 0.7 for summer months.&lt;/p&gt;&lt;p&gt;Furthermore, we present results from using the CML rainfall estimates to adjust radar rainfall fields. We extended the RADOLAN-method for radar-gauge adjustment for this purpose. The path-averaged CML rainfall information is compared to the gridded radar rainfall information at the path-intersecting grids. This information is then used in addition to the adjustments derived from rain gauges. We show first results of an hourly adjustment over several months. We further discuss the envisaged operational system for this application and give an outlook on the potential for radar rainfall field adjustments with higher temporal resolutions.&lt;/p&gt;&lt;p&gt;Graf, M., Chwala, C., Polz, J., and Kunstmann, H.: Rainfall estimation from a German-wide commercial microwave link network: optimized processing and validation for 1 year of data, Hydrol. Earth Syst. Sci., 24, 2931&amp;#8211;2950, https://doi.org/10.5194/hess-24-2931-2020, 2020&lt;/p&gt;&lt;p&gt;Polz, J., Chwala, C., Graf, M., and Kunstmann, H.: Rain event detection in commercial microwave link attenuation data using convolutional neural networks, Atmos. Meas. Tech., 13, 3835&amp;#8211;3853, https://doi.org/10.5194/amt-13-3835-2020, 2020&lt;/p&gt;

scholarly journals Effects of Organic Fertilization and Cover Crops on an Organic Pepper System

2008 ◽  
Vol 18 (2) ◽  
pp. 215-226 ◽  
Author(s):  
K. Delate ◽  
C. Cambardella ◽  
A. McKern
Keyword(s):  
Soil Fertility ◽  
Cover Crops ◽  
Cover Crop ◽  
Crop Production ◽  
Large Scale ◽  
Soil Analysis ◽  
Organic Fertilizer ◽  
The United States ◽  
Organic Fertilizers ◽  
Organic Farm

With the continuing 20% growth rate in the organic industry, organic vegetable crop production has increased to 98,525 acres in the United States. The requirement for certified organic vegetable producers to implement a soil-building plan has led to the development of soil fertility systems based on combinations of organic fertilizers and cover crops. To determine optimal soil fertility combinations, conventional and organic bell pepper (Capsicum annuum) production was evaluated from 2001 to 2003 in Iowa, comparing combinations of two synthetic fertilizers and three compost-based organic fertilizers, and a cover crop treatment of hairy vetch (Vicia villosa) and rye (Secale cereale) in a strip-tilled or fully incorporated cover crop system. Organic pepper growth and yields equaled or surpassed conventional production when nitrogen (N) was provided at 56 or 112 kg·ha−1 from compost-based organic fertilizer. Soil analysis revealed higher N in plots where cover crops were tilled compared with strip-tilled plots, leading to recommendations for sidedressing N in strip-tilled organic pepper production. Increased incidence of disease was also detected in strip-tilled plots. Postharvest weight loss after 6 weeks in storage was similar in organic and conventional peppers. The addition of calcium and sulfur products in conventional or organic fertilizer regimes did not increase pepper production or postharvest storage potential. Despite application challenges, cover crops will remain as critical components of the organic farm plan for their soil-building benefits, but supplementation with approved N sources may be required for optimal pepper production. Organic growers should conduct their own tests of organic-compliant soil amendments to determine cost effectiveness and value for their site before large-scale application.

scholarly journals Mechanisms of Pond Expansion in a Rapidly Submerging Marsh

2021 ◽  
Vol 8 ◽  
Author(s):  
Joshua Himmelstein ◽  
Orencio Duran Vinent ◽  
Stijn Temmerman ◽  
Matthew L. Kirwan
Keyword(s):  
Growth Rates ◽  
Large Scale ◽  
Time Window ◽  
Critical Time ◽  
Field Measurements ◽  
Physical Models ◽  
Primary Driver ◽  
Pond Size ◽  
Power Law Equation ◽  
Historical Photographs

The development and expansion of ponds within otherwise vegetated coastal marshes is a primary driver of marsh loss throughout the world. Previous studies propose that large ponds expand through a wind wave-driven positive feedback, where pond edge erosion rates increase with pond size, whereas biochemical processes control the formation and expansion of smaller ponds. However, it remains unclear which mechanisms dominate at a given scale, and thus how, and how fast, ponds increase their size. Here, we use historical photographs and field measurements in a rapidly submerging microtidal marsh to quantify pond development and identify the processes involved. We find that as small ponds emerge on the marsh platform, they quickly coalesce and merge, increasing the number of larger ponds. Pond expansion rates are maximized for intermediate size ponds and decrease for larger ponds, where the contribution of wave-driven erosion is negligible. Vegetation biomass, soil shear strength, and porewater biogeochemical indices of marsh health are higher in marshes adjacent to stable ponds than in those adjacent to unstable ponds, suggesting that pond growth rates are negatively related to the health of the surrounding marsh. We find that the model of Vinent et al. (2021) correctly predicts measured pond growth rates and size distribution, which suggest the different mechanisms driving pond growth are a result of marsh drowning due to sea level rise (SLR) and can be estimated by simplified physical models. Finally, we show that all relevant processes increasing pond size can be summarized by an empirical power-law equation for pond growth which predicts the temporal change of the maximum pond size as a lower bound for the total pond area in the system. This gives a timescale for the growth of ponds by merging and thus the critical time window for interventions to prevent the irreversible pond expansion associated with large scale pond merging.

scholarly journals Distributed security storage model for large-scale data

2017 ◽  
Vol 17 (04) ◽  
pp. 488-505 ◽  
Author(s):  
Ming Zhang ◽  
Wei Chen ◽  
Yunpeng Cao
Keyword(s):  
Large Scale ◽  
Storage Model ◽  
Large Scale Data ◽  
Distributed Security ◽  
Scale Data
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