Parallelization of the SUFI2 algorithm: a Windows HPC approach.

The Soil and Water Assessment Tool (SWAT) has been used for evaluating land use changes on water resources worldwide, and like many models, SWAT requires calibration. However, the execution time of these calibrations can be rather long, reducing the time available for proper analysis. This paper presents a Windows approach for calibrating SWAT using a multinodal cluster computer, composed of six computers with i7 processors (3.2 GHz; 12 cores), 8 GB RAM and 1 TB HDD each. The only requirement for this type of cluster is to have 64-bit processors. Our computers were setup with Windows Server HPC 2012 R2, a network switch 10/100, and regular Ethernet cables. We used the SUFI2 algorithm that comes with SWAT-CUP package to perform calibrations with 100 simulations at node level. Calibration runs were configured as follows: 1-12 (1 process interval), and 12-72 (12 processes interval), resulting in 17 runs. Each run was repeated three times, and results are presented as the mean execution time, in order to minimize any influence of resources fluctuations. Results showed that time of execution was reduced by almost half by using nine processes (15 min) in comparison with the one node control (28 min). We observed a linear decrease of execution time from one to nine processes. With additional processes, execution time increased about 23% and stabilized at 80% of the control. All processing is divided into five steps: distribute files (2.24% of all processing time), organize samples (0.89%), run SWAT (47.59%), collect results (46.51%) and cleanup (0.28%)

UTILIZACIÓN DE MODELOS HIDROLÓGICOS PARA LA DETERMINACIÓN DE CUENCAS EN ECOSISTEMAS DE PÁRAMO

El  presente  estudio  hidrológico  está  enfocado  al  análisis  de  la  red hídrica que se desprende del páramo de la Cortadera ubicado en los municipios de Toca y Siachoque (Boyacá, Colombia). Para el análisis realizado, la cuenca se dividió en cinco sub-cuencas debido al tamaño de esta y la confluencia de las aguas hacia la represa de la Copa sitio final de entrega de las mismas. Para la delimitación de la cuenca hidrográfica  se  tuvieron  en  cuenta  las  diferentes  sub-cuencas,  un análisis morfométrico, un modelo de elevación digital (DEM), Arcgis 9.3 y el programa SWAT (Soil and Water Assessment Tool). La información digital vectorial y raster a escala 1:250.000 utilizada fue aportada por la Corporación Autónoma Regional de Boyacá (CORPOBOYACA) y por el  Instituto Geográfico Agustín Codazzi (IGAC). El resultado obtenido permite conocer el comportamiento hidrológico de la cuenca total y de las cinco sub-cuencas como herramienta para la planeación y ordenamiento territorial, la toma de decisiones de carácter institucional y el manejo de los recursos naturales

Multiple solutions, multi-site, and parameter transfer to calibrate DHSVM hydrological model

The application of hydrologic models often needs sets of input parameters related to environmental attributes which are not always available. This leads to the necessity of calibrating the input parameters. However, due to the non-linearity of the hydrologic phenomena, there may be multiple “best” solutions for the calibration. This paper proposes a method for calibrating the DHSVM hydrologic model using the concepts of multiple solutions, multi-site, and parameter transfer among catchments. Eight watersheds were calibrated, resulting in obtaining five sets of “best” parameters (clusters) for each one. Afterward, each watershed was modeled using the parameters of the other catchments in order to verify if the transfer of the calibrated parameters could promote satisfactory modeling of the streamflows. The results show that clusters calibrated for one watershed may be suitable for other catchments. Besdes, the calibrated parameters of the smaller catchments were satisfactory to simulate the streamflow of the bigger catchments. The proposed method can be useful in calibrating and extrapolating the input parameters to regions that do not have information about them

Comparing two tools for ecosystem service assessments regarding water resources decisions

We present a comparison of two ecohydrologic models commonly used for planning land management to assess the production of hydrologic ecosystem services: the Soil and Water Assessment Tool (SWAT) and the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) annual water yield model. We compare these two models at two distinct sites in the US: the Wildcat Creek Watershed in Indiana and the Upper Upatoi Creek Watershed in Georgia. The InVEST and SWAT models provide similar estimates of the spatial distribution of water yield in Wildcat Creek, but very different estimates of the spatial distribution of water yield in Upper Upatoi Creek. The InVEST model may do a poor job estimating the spatial distribution of water yield in the Upper Upatoi Creek Watershed because baseflow provides a significant portion of the site’s total water yield, which means that storage dynamics which are not modeled by InVEST may be important. We also compare the ability of these two models, as well as one newly developed set of ecosystem service indices, to deliver useful guidance for land management decisions focused on providing hydrologic ecosystem services in three particular decision contexts: environmental flow ecosystem services, ecosystem services for potable water supply, and ecosystem services for rainfed irrigation. We present a simple framework for selecting models or indices to evaluate hydrologic ecosystem services as a way to formalize where models deliver useful guidance

EVALUATING FARGO-MOORHEAD FLOOD RISK MANAGEMENT PROJECT USING THE HYDROLOGIC AND WATER QUALITY SYSTEM

Spring floods in the Red River basin generated from melting snow have increasingly affected the Fargo-Moorhead metropolitan region of North Dakota and Minnesota within recent decades, causing serious economic damage and disturbance to the local community. Various local and federal government agencies have come together to formulate a flood management project mainly utilizing water diversion to protect the Fargo-Moorhead urban area from future floods. Major structural measures that alter the surface water flow regime would take place under the current project proposal. This study applied the Hydrologic and Water Quality System to set up the study watershed, covering the upper portion of the Red River basin with its outlet located in Fargo. The Soil and Water Assessment Tool Calibration and Uncertainty Procedures were used to perform sensitivity analysis, model calibration, and model validation on a chosen set of hydrologic input parameters. Results from one of the general circulation models, the Geophysical Fluid Dynamics Laboratory’s global coupled carbon-climate earth system model with vertical coordinates based on density, were coupled with the hydrologic model to set up predictive simulations to evaluate climate change impacts on the study watershed. A flood diversion channel was added into the predictive simulations in the form of point-source water extraction. The time durations for the predictive simulations were divided into two decade-long sections, 2026 to 2035 and 2036 to 2045, which represent the short- to medium-terms following project construction completion. Results of the predictive simulations indicate a significant increase in streamflow for the entire iii simulation time span under both RCP4.5 and RCP8.5 climate change scenarios. Meanwhile, the implementation of a diversion channel near the Fargo-Moorhead urban area would have a strong impact on the flow regime of the Red River at Fargo, where a streamflow pattern with lower average discharge and lower flow variability is predicted for the flood-diversion-included simulations. The inclusion of the flood diversion channel in the model also significantly reduces the occurrence of large-magnitude streamflow events

Efeito da resolução dos mapas de uso e ocupação da terra na resposta hidrológica na bacia do Rio Una/PE utilizando modelo SWAT

Several studies have extensively discussed the effects of land use/cover changes on the hydrological regime. The application of hydrological models to describe this type of process, with greater flexibility, rigor, and lower cost, has become promising for decision making. Therefore, the objective of this work was to evaluate the effect of land use/cover maps uncertainties on the Una River basin hydrological regime. In this work, the SWAT model was adopted for hydrological simulation, comparing IBGE and MapBiomas land use/cover changes maps. Firstly, careful work was done on database building, containing geospatial files and tabular data on the climatic conditions of the study region for 55 years period (1961-2016). The results obtained showed the feasibility of hydrological studies using computational modeling. The generalities presented in the IBGE data makes it less sensitive (when compared to the MapBiomas data) to the influences of land use/cover changes in the hydrological regime.Vários estudos têm discutido amplamente os efeitos das mudanças de uso e ocupação da terra no regime hidrológico. A aplicação de modelos hidrológicos para descrever esse tipo de processo, com maior flexibilidade, rigor e menor custo, tem se tornado promissor para a tomada de decisões. Sendo assim, o objetivo deste trabalho foi avaliar o efeito das incertezas dos mapas de uso e ocupação da terra sobre o regime hidrológico da bacia do rio Una. Neste trabalho foi adotado o modelo SWAT para simulação hidrológica, comparando os mapas das mudanças de uso e ocupação da terra do IBGE e do MapBiomas. Primeiramente, foi feito um trabalho cuidadoso na construção do banco de dados, contendo arquivos geoespaciais e dados tabulares sobre as condições climáticas da região de estudo por um período de 55 anos (1961-2016). Os resultados obtidos evidenciaram a viabilidade de estudos hidrológicos com recurso a modelagem computacional. A generalidade das classes de uso e ocupação da terra apresentadas no dado do IBGE, faz com que este seja menos sensível (quando comparado ao dado do MapBiomas) às influências das mudanças de uso e ocupação da terra no regime hidrológico

Development of a GPGPU accelerated tool to simulate advection-reaction-diffusion phenomena in 2D

Computational models are powerful tools to the study of environmental systems, playing a fundamental role in several fields of research (hydrological sciences, biomathematics, atmospheric sciences, geosciences, among others). Most of these models require high computational capacity, especially when one considers high spatial resolution and the application to large areas. In this context, the exponential increase in computational power brought by General Purpose Graphics Processing Units (GPGPU) has drawn the attention of scientists and engineers to the development of low cost and high performance parallel implementations of environmental models. In this research, we apply GPGPU computing for the development of a model that describes the physical processes of advection, reaction and diffusion. This presentation is held in the form of three self-contained articles. In the first one, we present a GPGPU implementation for the solution of the 2D groundwater flow equation in unconfined aquifers for heterogenous and anisotropic media. We implement a finite difference solution scheme based on the Crank- Nicolson method and show that the GPGPU accelerated solution implemented using CUDA C/C++ (Compute Unified Device Architecture) greatly outperforms the corresponding serial solution implemented in C/C++. The results show that accelerated GPGPU implementation is capable of delivering up to 56 times acceleration in the solution process using an ordinary office computer. In the second article, we study the application of a diffusive-logistic growth (DLG) model to the problem of forest growth and regeneration. The study focuses on vegetation belonging to preservation areas, such as riparian buffer zones. The study was developed in two stages: (i) a methodology based on Artificial Neural Network Ensembles (ANNE) was applied to evaluate the width of riparian buffer required to filter 90% of the residual nitrogen; (ii) the DLG model was calibrated and validated to generate a prognostic of forest regeneration in riparian protection bands considering the minimum widths indicated by the ANNE. The solution was implemented in GPGPU and it was applied to simulate the forest regeneration process for forty years on the riparian protection bands along the Ligeiro river, in Brazil. The results from calibration and validation showed that the DLG model provides fairly accurate results for the modelling of forest regeneration. In the third manuscript, we present a GPGPU implementation of the solution of the advection-reaction-diffusion equation in 2D. The implementation is designed to be general and flexible to allow the modeling of a wide range of processes, including those with heterogeneity and anisotropy. We show that simulations performed in GPGPU allow the use of mesh grids containing more than 20 million points, corresponding to an area of 18,000 km? in a standard Landsat image resolution.Os modelos computacionais s?o ferramentas poderosas para o estudo de sistemas ambientais, desempenhando um papel fundamental em v?rios campos de pesquisa (ci?ncias hidrol?gicas, biomatem?tica, ci?ncias atmosf?ricas, geoci?ncias, entre outros). A maioria desses modelos requer alta capacidade computacional, especialmente quando se considera uma alta resolu??o espacial e a aplica??o em grandes ?reas. Neste contexto, o aumento exponencial do poder computacional trazido pelas Unidades de Processamento de Gr?ficos de Prop?sito Geral (GPGPU) chamou a aten??o de cientistas e engenheiros para o desenvolvimento de implementa??es paralelas de baixo custo e alto desempenho para modelos ambientais. Neste trabalho, aplicamos computa??o em GPGPU para o desenvolvimento de um modelo que descreve os processos f?sicos de advec??o, rea??o e difus?o. Esta disserta??o ? apresentada sob a forma de tr?s artigos. No primeiro, apresentamos uma implementa??o em GPGPU para a solu??o da equa??o de fluxo de ?guas subterr?neas 2D em aqu?feros n?o confinados para meios heterog?neos e anisotr?picos. Foi implementado um esquema de solu??o de diferen?as finitas com base no m?todo Crank- Nicolson e mostramos que a solu??o acelerada GPGPU implementada usando CUDA C / C ++ supera a solu??o serial correspondente implementada em C / C ++. Os resultados mostram que a implementa??o acelerada por GPGPU ? capaz de fornecer acelera??o de at? 56 vezes no processo da solu??o usando um computador de escrit?rio comum. No segundo artigo estudamos a aplica??o de um modelo de crescimento log?stico difusivo (DLG) ao problema de crescimento e regenera??o florestal. O estudo foi desenvolvido em duas etapas: (i) Aplicou-se uma metodologia baseada em Comites de Rede Neural Artificial (ANNE) para avaliar a largura da faixa de prote??o rip?ria necess?ria para filtrar 90% do nitrog?nio residual; (ii) O modelo DLG foi calibrado e validado para gerar um progn?stico de regenera??o florestal em faixas de prote??o rip?rias considerando as larguras m?nimas indicadas pela ANNE. A solu??o foi implementada em GPGPU e aplicada para simular o processo de regenera??o florestal para um per?odo de quarenta anos na faixa de prote??o rip?ria ao longo do rio Ligeiro, no Brasil. Os resultados da calibra??o e valida??o mostraram que o modelo DLG fornece resultados bastante precisos para a modelagem de regenera??o florestal. No terceiro artigo, apresenta-se uma implementa??o em GPGPU para solu??o da equa??o advec??o-rea??o-difus?o em 2D. A implementa??o ? projetada para ser geral e flex?vel para permitir a modelagem de uma ampla gama de processos, incluindo caracter?sticas como heterogeneidade e anisotropia do meio. Neste trabalho mostra-se que as simula??es realizadas em GPGPU permitem o uso de malhas contendo mais de 20 milh?es de pontos (vari?veis), correspondendo a uma ?rea de 18.000 km? em resolu??o de 30m padr?o das imagens Landsat

Water Cycle and Circular Economy: Developing a Circularity Assessment Framework for Complex Water Systems

© 2020 The Authors. Water – the most vital resource, negatively affected by the linear pattern of growth – still tries to find its positioning within the emerging concept of circular economy. Fragmented, sectorial circularity approaches hide the risk of underestimating both the preservation of and impacts to water resources and natural capital. In this study, a game changing circularity assessment framework is developed (i.e. MSWCA). The MSWCA follows a multi-sectoral systems approach, symbiotically managing key water-related socio-economic (i.e. urban water, agro-food, energy, industry and waste handling) and non-economic (i.e. natural environment) sectors. The MSWCA modelling framework enables the investigation of the feedback loops between the nature-managed and human-managed systems to assess water and water-related resources circularity. The three CE principles lie at the core of the developed framework, enabling the consideration of physical, technical, environmental and economic aspects. An indicators database is further developed, including all the relevant data requirements, as well as existing and newly developed indicators assessing multi-sectoral systems’ circularity. The MSWCA framework is conceptually applied to a fictional city, facilitating its understanding and practical use.Horizon 2020 research and innovation program HYDROUSA (grant agreement No 776643)

EVALUATING FARGO-MOORHEAD FLOOD RISK MANAGEMENT PROJECT USING THE HYDROLOGIC AND WATER QUALITY SYSTEM

Spring floods in the Red River basin generated from melting snow have increasingly affected the Fargo-Moorhead metropolitan region of North Dakota and Minnesota within recent decades, causing serious economic damage and disturbance to the local community. Various local and federal government agencies have come together to formulate a flood management project mainly utilizing water diversion to protect the Fargo-Moorhead urban area from future floods. Major structural measures that alter the surface water flow regime would take place under the current project proposal. This study applied the Hydrologic and Water Quality System to set up the study watershed, covering the upper portion of the Red River basin with its outlet located in Fargo. The Soil and Water Assessment Tool Calibration and Uncertainty Procedures were used to perform sensitivity analysis, model calibration, and model validation on a chosen set of hydrologic input parameters. Results from one of the general circulation models, the Geophysical Fluid Dynamics Laboratory’s global coupled carbon-climate earth system model with vertical coordinates based on density, were coupled with the hydrologic model to set up predictive simulations to evaluate climate change impacts on the study watershed. A flood diversion channel was added into the predictive simulations in the form of point-source water extraction. The time durations for the predictive simulations were divided into two decade-long sections, 2026 to 2035 and 2036 to 2045, which represent the short- to medium-terms following project construction completion. Results of the predictive simulations indicate a significant increase in streamflow for the entire iii simulation time span under both RCP4.5 and RCP8.5 climate change scenarios. Meanwhile, the implementation of a diversion channel near the Fargo-Moorhead urban area would have a strong impact on the flow regime of the Red River at Fargo, where a streamflow pattern with lower average discharge and lower flow variability is predicted for the flood-diversion-included simulations. The inclusion of the flood diversion channel in the model also significantly reduces the occurrence of large-magnitude streamflow events