scholarly journals Adaptive hybrid architecture for enhancement of the complex hydroclimatic system and assessment of freshwater security

2021 ◽  
Author(s):  
Venkatesh Budamala ◽  
Amit Baburao Mahindrakar
Keyword(s):  
Parallel Computing ◽  
Adaptive Sampling ◽  
Model Fitting ◽  
Water Security ◽  
Spatial Optimization ◽  
Climatic Conditions ◽  
Hybrid Architecture ◽  
Significant Information ◽  
Vulnerability Indicators ◽  
Model Efficiency

Abstract Future freshwater security relies on hydroclimatic (HC) shifts and regimes for sustainable development. The approximation of the HC system faces major uncertainties and complexities due to the incorporation of heavy datasets, characteristics, and constraints. The proposed study focused on the parallel computing of emulator modeling-based spatial optimization to enhance the HC systems with the perspective of future freshwater security in the Upper Chattahoochee River basin (UCR). Here, the framework compiles both physical and machine learning concepts with adaptive technology for the replication of real-world scenarios. Besides, it contains 2Emulator Model Fitting, Spatial Optimization, Parallel Computing, and Initial and Adaptive sampling to upgrade model efficiency. While UCR has inadequate groundwater and the assessment of freshwater security in UCR is more necessary for varying future climatic conditions. The results displayed that the proposed spatial optimization algorithm proved to be an effective and efficient approach in the approximation of HC models. The assessment of water security in UCR was showed in terms of scarcity and vulnerability indicators for median and low-level conditions, respectively. Moreover, this study provides the potential framework for the enhancement of physical model predictions with the incorporation of hybrid concepts for problem-solving technology which can provide significant information on HC issues.

The measurement time required for determining total NH3 losses after field application of slurries by trail hoses

2012 ◽  
Vol 151 (1) ◽  
pp. 34-43 ◽  
Author(s):  
K. NI ◽  
A. PACHOLSKI ◽  
D. GERICKE ◽  
H. KAGE
Keyword(s):  
Western Europe ◽  
Field Experiments ◽  
Model Fitting ◽  
Climatic Conditions ◽  
Field Application ◽  
Organic Fertilizers ◽  
Measurement Time ◽  
Linear Coefficient ◽  
Close Relationship ◽  
Time Required

SUMMARYMonitoring ammonia (NH3) emission is time consuming and requires specialized measurement equipment. The measurement time can be reduced if there is a close relationship between time and subsequent cumulated NH3 emission values. A statistical analysis was employed to study the relationship between cumulative NH3 emissions over varying time intervals and final NH3 loss after 3 days of measurement. A large number of multi-plot field experiments on NH3 loss after the application of animal and biogas slurries by trail hoses to crops in Northern Germany were carried out from 2007 to 2010. Based on data from 2007, measured using a passive sampler method, a linear empirical model was developed to calculate final cumulated NH3 loss from intermediate cumulated losses. Linear model fitting showed that cumulative NH3 losses after 24 h were significantly correlated with final cumulated NH3 losses, explaining more than 0·98 of its variation. The linear coefficient was 1·34, implying that c. 0·73 of final NH3 loss occurred within the first 24 h. Validation by datasets obtained from another year (2008), two additional measurement methods and another agro-region (marsh area, 2009/10) resulted in a close agreement of model predictions with measured data within the range of model uncertainty and data variation. The results underpin the feasibility of calculating final NH3 losses from cumulative losses during first 24 h after slurry application and can be used to simplify NH3 loss measurement after the application of liquid slurries in multi-plot field experiments. The slope of the linear relationship is only valid for liquid slurries and the environmental conditions of the present study, which are typical for many agro-regions in north-western Europe, and will have to be adapted for different climatic conditions. A time-efficient measurement of emissions from solid organic fertilizers might require a different time span.

scholarly journals Flooding Regime Impacts on Radiation, Evapotranspiration, and Latent Energy Fluxes over Groundwater-Dependent Riparian Cottonwood and Saltcedar Forests

2015 ◽  
Vol 2015 ◽  
pp. 1-14 ◽  
Author(s):  
James Cleverly ◽  
James R. Thibault ◽  
Stephen B. Teet ◽  
Paul Tashjian ◽  
Lawrence E. Hipps ◽  
...  
Keyword(s):  
Heat Flux ◽  
Evaporative Cooling ◽  
Sensible Heat Flux ◽  
Water Security ◽  
Climatic Conditions ◽  
Energy Budgets ◽  
Energy Fluxes ◽  
Management Options ◽  
Flooding Regime ◽  
Substantial Decline

Radiation and energy balances are key drivers of ecosystem water and carbon cycling. This study reports on ten years of eddy covariance measurements over groundwater-dependent ecosystems (GDEs) in New Mexico, USA, to compare the role of drought and flooding on radiation, water, and energy budgets of forests differing in species composition (native cottonwoodversusnonnative saltcedar) and flooding regime. After net radiation (700–800 W m−2), latent heat flux was the largest energy flux, with annual values of evapotranspiration exceeding annual precipitation by 250–600%. Evaporative cooling dominated the energy fluxes of both forest types, although cottonwood generated much lower daily values of sensible heat flux (<−5 MJ m−2 d−1). Drought caused a reduction in evaporative cooling, especially in the saltcedar sites where evapotranspiration was also reduced, but without a substantial decline in depth-to-groundwater. Our findings have broad implications on water security and the management of native and nonnative vegetation within semiarid southwestern North America. Specifically, consideration of the energy budgets of GDEs as they respond to fluctuations in climatic conditions can inform the management options for reducing evapotranspiration and maintaining in-stream flow, which is legally mandated as part of interstate and international water resources agreements.

scholarly journals Evaluating Hydrological Models for Deriving Water Resources in Peninsular Spain

2019 ◽  
Vol 11 (10) ◽  
pp. 2872 ◽  
Author(s):  
Julio Pérez-Sánchez ◽  
Javier Senent-Aparicio ◽  
Francisco Segura-Méndez ◽  
David Pulido-Velazquez ◽  
Raghavan Srinivasan
Keyword(s):  
Aridity Index ◽  
Information Criterion ◽  
Climatic Conditions ◽  
Coefficient Of Determination ◽  
Efficiency Coefficient ◽  
Run Off ◽  
Margin Of Error ◽  
Model Efficiency ◽  
Flow Duration Curves ◽  
Peninsular Spain

Water availability is essential for the appropriate analysis of its sustainable management. We performed a comparative study of six hydrological balance models (Témez, ABCD, GR2M, AWBM, GUO-5p, and Thornthwaite-Mather) in several basins with different climatic conditions within Spain in the 1977–2010 period. We applied six statistical indices to compare the results of the models: the Akaike information criterion (AIC), the Bayesian information criterion (BIC), Nash–Sutcliffe model efficiency coefficient (NSE), coefficient of determination (R2), percent bias (PBIAS), and the relative error between observed and simulated run-off volumes (REV). Furthermore, we applied the FITEVAL software to determine the uncertainty of the model. The results show that when the catchments are more humid the obtained results are better. The GR2M model gave the best fit in peninsular Spain in a UNEP aridity index framework above 1, and NSE values above 0.75 in a 95% confidence interval classify GR2M as very good for humid watersheds. The use of REV is also a key index in the assessment of the margin of error. Flow duration curves show good performance in the probabilities of exceedance lower than 80% in wet watersheds and deviations in low streamflows account for less than 5% of the total streamflow.

scholarly journals Soybean yield in the Matopiba region under climate changes

2020 ◽  
Vol 24 (1) ◽  
pp. 8-14
Author(s):  
Vicente de P. R. da Silva ◽  
Roberta A. e Silva ◽  
Girlene F. Maciel ◽  
Enio P. de Souza ◽  
Célia C. Braga ◽  
...  
Keyword(s):  
Climate Models ◽  
Co2 Concentration ◽  
Climatic Conditions ◽  
Coefficient Of Determination ◽  
Climate Change Scenarios ◽  
Efficiency Coefficient ◽  
Soybean Yield ◽  
Aquacrop Model ◽  
Model Efficiency ◽  
Rcp 8.5

ABSTRACT The climatic conditions along the cycle are the main factors responsible for the final production of any crop. This study aimed to evaluate the current conditions and the effects of climate change scenarios on the yield of soybean grown in the Matopiba region, located between the states of Tocantins, south and northeast of Maranhão, south of Piauí and west of Bahia, Brazil. The AquaCrop model of FAO, version 5.0, was calibrated with data of 2014 and validated with those of 2016, using climate, soil and crop management parameters collected in two experimental campaigns conducted between June and October in 2014 and 2016 in Palmas, TO, Brazil. The performance of the model was evaluated using the following statistical indicators: prediction error (PE), coefficient of determination (R2), normalized root mean square error (NRMSE), Nash-Sutcliffe model efficiency coefficient (EF) and Willmott’s index of agreement (d). It was verified that the AquaCrop model underestimates soybean grain yield under severe water stress conditions throughout the growing cycle. The increase in CO2 concentration and in the air temperature, projected by the climate models HadGEM2-ES and MIROC5 under the scenario of stabilization (RCP 4.5) and the scenario of progression (RCP 8.5), have contributed to the increase in soybean yield by the end of this century.

scholarly journals Artificial Floating Island with Vetiver for Treatment of Arsenic-Contaminated Water: A Real Scale Study in High-Andean Reservoir

Water ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3086
Author(s):  
Kalina Marcela Fonseca Largo ◽  
Joseline Luisa Ruiz Depablos ◽  
Edgar Fabián Espitia-Sarmiento ◽  
Nataly Marisol Llugsha Moreta
Keyword(s):  
Arsenic Removal ◽  
Water Security ◽  
Climatic Conditions ◽  
Contaminated Water ◽  
Floating Island ◽  
Batch Type ◽  
Water Treatments ◽  
Real Scale ◽  
Agriculture Water ◽  
Geogenic Arsenic

Arsenic found in agriculture water reservoirs represents a threat to water security and safe agricultural products in developing countries. Small farms do not implement traditional water treatments due to the high cost; hence, a nature-based solution is an alternative to tackling this challenge. This paper investigated the potential of artificial floating island with Vetiver (AFIV) for the geogenic arsenic removal present in the reservoir of the Ilinizas páramo in Ecuador. We constructed two AFIV systems using PVC pipes in a reservoir batch type with a 3.6 m3 treatment capacity. Arsenic and iron were analyzed in duplicated every 30 days at the affluent and effluent through 120 days. The average remediation of arsenic was recorded as 97% in water and 84% in sediment, while the average remediation of iron was 87% in sediment. The survival rate of macrophytes was 92%; they accumulated arsenic in its roots that acted as a barrier against the translocation. The research demonstrated that the use of AFIV has the potential to rehabilitate reservoirs contaminated with arsenic under adverse climatic conditions such as the páramo ecosystem.

scholarly journals Uncertainty in the Number of Calibration Repetitions of a Hydrologic Model in Varying Climatic Conditions

Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2362
Author(s):  
Patrik Sleziak ◽  
Ladislav Holko ◽  
Michal Danko ◽  
Juraj Parajka
Keyword(s):  
Differential Evolution Algorithm ◽  
Model Performance ◽  
Hydrologic Model ◽  
Climatic Conditions ◽  
Data Set ◽  
Climate Conditions ◽  
Daily Data ◽  
Model Efficiency ◽  
The Difference ◽  
The Impact

The objective of this study is to examine the impact of the number of calibration repetitions on hydrologic model performance and parameter uncertainty in varying climatic conditions. The study is performed in a pristine alpine catchment in the Western Tatra Mountains (the Jalovecký Creek catchment, Slovakia) using daily data from the period 1989–2018. The entire data set has been divided into five 6-years long periods; the division was based on the wavelet analysis of precipitation, air temperature and runoff data. A lumped conceptual hydrologic model TUW (“Technische Universität Wien”) was calibrated by an automatic optimisation using the differential evolution algorithm approach. To test the effect of the number of calibrations in the optimisation procedure, we have conducted 10, 50, 100, 300, 500 repetitions of calibrations in each period and validated them against selected runoff and snow-related model efficiency criteria. The results showed that while the medians of different groups of calibration repetitions were similar, the ranges (max–min) of model efficiency criteria and parameter values differed. An increasing number of calibration repetitions tend to increase the ranges of model efficiency criteria during model validation, particularly for the runoff volume error and snow error, which were not directly used in model calibration. Comparison of model efficiencies in climate conditions that varied among the five periods documented changes in model performance in different periods but the difference between 10 and 500 calibration repetitions did not change much between the selected time periods. The results suggest that ten repetitions of model calibrations provided the same median of model efficiency criteria as a greater number of calibration repetitions and model parameter variability and uncertainty were smaller.

scholarly journals Projection of land use to 2030 and its impacts on water availability in a brazilian sub-basin: A LCM and SWAT approach

2022 ◽  
Vol 61 (1) ◽  
pp. 66-87
Author(s):  
Adriana Paulo de Sousa Oliveira ◽  
Rafaela Ribeiro Gracelli ◽  
Arthur Amaral e Silva ◽  
Vitor Juste dos Santos ◽  
Jackeline De Siqueira Castro ◽  
...  
Keyword(s):  
Land Use ◽  
Water Resources ◽  
Water Resources Management ◽  
Water Availability ◽  
Assessment Tool ◽  
Swat Model ◽  
Water Security ◽  
Climatic Conditions ◽  
Southeastern Brazil ◽  
Resources Management

Changes in land use and land cover (LULC) can result in significant changes in a hydrographic ba- sin flow regime. Future projections about LULC and its interference with water availability help to identify extreme events in advance and help propose appropriate management measures. Thus, this study aimed to make the LULC projection for the year 2030 for the Alto Rio Grande (ARG) sub- basin, located in Southeastern Brazil. This region was chosen because of its intense water resources use and for having recently faced water scarcity as result of prolonged droughts and inadequate water resources management. To identify the LULC trend for the year 2030, the Land Change Modeler (LCM) was used, the map obtained was inserted in the Soil and Water Assessment Tool (SWAT) model previously calibrated and validated for the region’ environmental and climatic conditions. The ARG sub-basin was affected by heavy rains in 2011, which resulted in changes in the landscape due to landslides. This particularity of the region contributed to the projection of LULC for the year 2030 to present an increase in forest and pastures to the agricultural areas detriment. When evaluating the impacts of these changes in water availability, it was observed that the SWAT model presented, for the same rainfall conditions, a reduction in peak streamflows of up to 59% and a reduction in the average monthly flow of up to 63% in 2030 in relation to the LULC observed in 2017. Thus, this study provides an important contribution by identifying a considerable reduction in water availability. These results will help to formulate strategies for water resources management and the adoption of measures to promote water security in the region.

On improving the efficiency of mathematical modeling of the problem of stability of construction

2020 ◽  
Vol 25 (3) ◽  
pp. 27-36
Author(s):  
Chistyakov A.V. ◽  
Keyword(s):  
Mathematical Modeling ◽  
Parallel Computing ◽  
Parallel Algorithms ◽  
High Performance ◽  
Sparse Matrices ◽  
Multicore Processors ◽  
Automatic Parallelization ◽  
Hybrid Architecture ◽  
Graphics Processors ◽  
Algorithmic Software

Algorithmic software for mathematical modeling of structural stability is considered, which is reduced to solving a partial generalized eigenvalues problem of sparse matrices, with automatic parallelization of calculations on modern parallel computers with graphics processors. Peculiarities of realization of parallel algorithms for different structures of sparse matrices are presented. The times of solving the problem of stability of composite materialsusing a three-dimensional model of "finite size fibers" on computers of different architectures are given. In mathematical modeling of physical and technical processes in many cases there is a need to solve problems of algebraic problem of eigenvalues (APVZ) with sparse matrices of large volumes. In particular, such problems arise in the analysis of the strength of structures in civil and industrial construction, aircraft construction, electric welding, etc. The solving to these problems is to determine the eigenvalues and eigenvectors of sparse matrices of different structure. The efficiency of solving these problems largely depends on the effectiveness of mathematical modeling of the problem as a whole. Continuous growth of task parameters, calculation of more complete models of objects and processes on computers require an increase in computer productivity. High-performance computing requirements are far ahead of traditional parallel computing, even with multicore processors. High-performance computing requirements are far ahead of traditional parallel computing, even with multicore processors. Today, this problem is solved by using powerful supercomputers of hybrid architecture, such as computers with multicore processors (CPUs) and graphics processors (GPUs), which combine MIMD and SIMD architectures. But the potential of high-performance computers can be used to the fullest only with algorithmic software that takes into account both the properties of the task and the features of the hybrid architecture. Complicating the architecture of modern high-performance supercomputers of hybrid architecture, which are actively used for mathematical modeling (increasing the number of computer processors and cores, different types of computer memory, different programming technologies, etc.) means a significant complication of efficient use of these resources in creating parallel algorithms and programs. here are problems with the creation of algorithmic software with automatic execution of stages of work, which are associated with the efficient use of computing resources, ways to store and process sparse matrices, analysis of the reliability of computer results. This makes it possible to significantly increase the efficiency of mathematical modeling of practical problems on modern high-performance computers, as well as free users from the problems of parallelization of complex problems. he developed algorithmic software automatically implements all stages of parallel computing and processing of sparse matrices on a hybrid computer. It was used at the Institute of Mechanics named after S.P. Tymoshenko NAS of Ukraine in modeling the strength problems of composite material. A significant improvement in the time characteristics of mathematical modeling was obtained. Problems of mathematical modeling of the properties of composite materials has an important role in designing the processes of deformation and destruction of products in various subject areas. Algorithmic software for mathematical modeling of structural stability is considered, which is reduced to solving a partial generalized problem of eigen values of sparse matrices of different structure of large orders, with automatic parallelization of calculations on modern parallel computers with graphics processors. The main methodological principles and features of implementation of parallel algorithms for different structures of sparse matrices are presented, which ensure effective implementation of multilevel parallelism of a hybrid system and reduce data exchange time during the computational process. As an example of these approaches, a hybrid algorithm of the iteration method in subspace for tape and block-diagonal matrices with a frame for computers of hybrid architecture is given. Peculiarities of data decomposition for matrices of profile structure at realization of parallel algorithms are considered. The proposed approach provides automatic determination of the required topology of the hybrid computer and the optimal amount of resources for the organization of an efficient computational process. The results of testing the developed algorithmic software for problems from the collection of the University of Florida, as well as the times of solving the problem of stability of composite materials using a three-dimensional model of "finite size fibers" on computers of different architectures. The results show a significant improvement in the time characteristics of solving problems.

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