Sefficiency (sustainable efficiency) and reallocation of watre using agricultura and urban scenarios

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Análise da quantidade de azoto em excesso em solos agrícolas na zona vulnerável n.º 1

O conceito de Zona Vulnerável com vista a proteger as águas contra a poluição difusa causada por nitratos de origem agrícola, foi definido na Directiva 91/676/CEE, publicada no Jornal Oficial das Comunidades de 31 de Dezembro de 1997, a qual foi transposta para a ordem jurídica interna pelo Dec-Lei 235/97 de 3 de Setembro. Os objectivos deste diploma são: a redução da poluição das águas contra a poluição causada por nitratos de origem agrícola, bem como impedir a propagação desta poluição (artº 2). Com o presente trabalho pretende-se elaborar um modelo que permita quantificar a produção de chorume bovino que é um dos principais factores influentes na concentração de nitratos na Zona Vulnerável nº 1 Esposende – Vila do Conde

Random walk forecast of urban water in Iran under uncertainty

There are two significant reasons for the uncertainties of water demand. On one hand, an evolving technological world is plagued with accelerated change in lifestyles and consumption patterns; and on the other hand, intensifying climate change. Therefore, with an uncertain future, what enables policymakers to define the state of water resources, which are affected by withdrawals and demands? Through a case study based on thirteen years of observation data in the Zayandeh Rud River basin in Isfahan province located in Iran, this paper forecasts a wide range of urban water demand possibilities in order to create a portfolio of plans which could be utilized by different water managers. A comparison and contrast of two existing methods are discussed, demonstrating the Random Walk Methodology, which will be referred to as the â On uncertainty pathâ , because it takes the uncertainties into account and can be recommended to managers. This On Uncertainty Path is composed of both dynamic forecasting method and system simulation. The outcomes show the advantage of such methods particularly for places that climate change will aggravate their water scarcity, such as Iran

An Introduction to the Hyperspace of Hargreaves-Samani Reference Evapotranspiration

Climate change has been shown to directly influence evapotranspiration, which is one of the crucial watershed processes. The common approach to its calculation is via mathematical equations, such as 1985 Hargreaves-Samani (HS85). It computes reference evapotranspiration (ETo) through three climatic variables and one constant: RA (extra-terrestrial radiation), TC (mean temperature), TR (temperature range) and KR (empirical coefficient). To make HS85 more accurate, one of its authors proposed an equation for KR as a function of TR in 2000 (HS00). Both models are 4D and their internal behaviours are difficult to understand, hence, the data driven applications prevalent among experts and managers. In this study, we introduce an innovative research by trying to respond to two questions. What are the relationships between TC and TR? What are the internal patterns of HS hyperspace (4D domain) and the changes in ETo possibilities of the two models? In the proposed approach, thresholds for the four variables are utilized to cover majority of the agroclimatic situations in the world and the hyperspace is discretized with more than 50,000 calculation nodes. The ETo results show that under various climatic conditions, the behaviour of HS is nonlinear (more for HS00) leading to an increased uncertainty particularly for data driven applications. TC and TR show patterns useful for regions with less data.This work was partially financed by (a) the Portuguese Foundation for Science and Technology (FCT) under the contract UID/ECI/04047/2013 for the Centre of Territory, Environment and Construction(CTAC) of the University of Minho, (b) project POCI-01-0145-FEDER-028247 - funded by FEDER funds throughCOMPETE2020—Programa Operacional Competitividade e Internacionalização (POCI) and by national funds (PIDDAC) through FCT/MCTES. Acknowledgments: The authors appreciate the cooperation of the Cluster computing facilities of the University of Minho developed under the Project ‘Search-ON2: Revitalization of HPC infrastructure of UMinho’ (NORTE-07-0162-FEDER-000086), co-funded by the North Portugal Regional Operational Programme (ON.2—O Novo Norte), under the National Strategic Reference Framework (NSRF), through the European Regional Development Fund (ERDF).info:eu-repo/semantics/publishedVersio

Application of RIAM to the environmental impact assessment of hydroelectric installations

This paper evaluates an Environmental Impact Assessment (EIA) using the Rapid Impact Assessment Matrix (RIAM). It analyses and presents in a structured, friendly and transparent environment the numerous parameters and alternatives of an EIA. It considers all 4 components: physical / chemical, biological / ecological, social / cultural, economic / operational. These are then evaluated using universal criteria common to all impact consideration. Figures and tables made comparisons much easier. This Matrix was applied to the EIA of the future Vale de Madeira Hydroelectric Installation that will be situated on the River Côa of the Douro River Basin in the Municipalities of Pinhel and Figueira de Castelo Rodrigo, North of Portugal. It will be shown that such a project will be positive economically but negative otherwise (as related to the other three components evaluated in RIAM)

Irrigation water use and its effective efficiency in Portugal

The 2007 report of the Intergovernmental Panel on Climate Change (IPCC) projected with high confidence that the conditions (drought and high temperatures) in the Southern Europe will worsen. It stated that this region that includes Portugal is already vulnerable and will experience a reduction in water availability, hydropower potential and crop yield and productivity. The evidence of such conditions have already struck Portugal when during the 2004-2005 hydrological year experienced one of its worst droughts in decades. Between June to September 2005, the whole country was classified as experiencing sever to extreme drought according to the Palmer Drought Severity Index (PDSI). At the same time, Portugal was developing its new Water Law based on the requirements of the so called Water Framework Directive of the European Union. Its Article 11 states that one of the basic and required measures is to promote efficient and sustainable use of water. As a consequence of these two factors, the Portuguese Government adopted a series of adaptation measures, one of them being a ten year National Program for Efficient Use of Water. This paper will present this program in its irrigation water use, analyse its effective efficiency and discuss advantages and disadvantages of the portfolio of measures that are being considered. Until recently, classical efficiency defined as the ratio of the beneficial output to input was mostly used to calculate irrigation water efficiency. But in this study, the effective efficiency (EE) indicator was used which is defined as the ratio of beneficial output to the effective demand. Beneficial output is essentially net evapotranspiration. The preliminary results show an EE of about 60% corresponding to an effective water demand of about 6.6 billion cubic meter per year. This quantity of water is more than 85% of total water demand in Portugal. The cost of supplying this amount of water is estimated to be about half a billion Euros per year resulting in about 200 millions of Euros of losses. Some specific results of two river basins namely the international Douro River Basin will be presented in this paper. The Program sets a goal of improving the EE to 65% to be achieved in 10 years by 2015. Four areas of intervention were proposed to achieve this goal: information and education, training and technical help, legislation and normalisation, and Measurement and conversion of equipments of water use

Hargreaves and other reduced-set methods for calculating evapotranspiration

This edition of Evapotranspiration - Remote Sensing and Modeling contains 23 chapters related to the modeling and simulation of evapotranspiration (ET) and remote sensing-based energy balance determination of ET. These areas are at the forefront of technologies that quantify the highly spatial ET from the Earth's surface. The topics describe mechanics of ET simulation from partially vegetated surfaces and stomatal conductance behavior of natural and agricultural ecosystems. Estimation methods that use weather based methods, soil water balance, the Complementary Relationship, the Hargreaves and other temperature-radiation based methods, and Fuzzy-Probabilistic calculations are described. A critical review describes methods used in hydrological models. Applications describe ET patterns in alpine catchments, under water shortage, for irrigated systems, under climate change, and for grasslands and pastures. Remote sensing based approaches include Landsat and MODIS satellite-based energy balance, and the common process models SEBAL, METRIC and S-SEBS. Recommended guidelines for applying operational satellite-based energy balance models and for overcoming common challenges are made

Modelling of smart irrigation with replan and redistribution algorithms

It is a priority develop intelligent irrigation systems to save water. Using optimal control formulations and techniques, the water consumption can be made to follow more closely the hydrological needs of the crop, taking into account current weather conditions. Here, the mathematical model presented by the authors in previous publications is improved. This new model incorporates new features like the slope of the soil, the possibility to include a percentage of water losses due to runoff, and a percentage of water losses if the soil is on the field capacity. A new and efficient replan strategy is applied tacking into account the data measured from moisture sensors, to ensure that hydric needs of the crop is fulfilled. A new approach to deal with multiple irrigation points is also proposed. It allows to redistribute the available water in the case an irrigation point is not able to provide the water needed.FEDER/COMPETE/NORTE2020/POCI/FCT funds through grants [UID/EEA/-00147/20 13/UID/IEEA/00147/ 006933-SYSTEC], project, To CHAIR – [POCI-01-0145-FEDER028247] and [UPWIND - POCI-FEDER-FCT -31447]. This work was also supported by the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Funding [UID/FIS/04650/2019], [UIDB/00013/2020] and [UIDP/00013/2020 of CMAT-UM]

Desenvolvimento dum sistema de rega automático, autónomo e adaptativo – estudo comparativo de cinco métodos para o cálculo da ETo

Para efeitos de desenvolvimento dum sistema de rega automático, são estudados e calibrados cinco métodos de cálculo de Evapotranspiração de referência (Priestley-Taylor, Makkink, Hargreaves, Turc, Jensen-Haise) utilizando apenas os parâmetros climáticos temperatura, T, e radiação solar, Rs. O estudo envolve o cálculo da Evapotranspiração para todos os dias do ano hidrológico 2005/06 e a sua comparação com o método de Penman-Monteith. A estação escolhida para o estudo é a estação de Divor. Nas condições do estudo (Sul da Península Ibérica) os melhores resultados são obtidos com os métodos de Priestley-Taylor e Jensen-Haise. São apresentados os coeficientes de calibração para todos os cinco métodos para a zona do estudo, por forma a aproximar ao máximo os resultados aos obtidos pelo método de referência.In order to develop an automatic irrigation system, a set of five different methods for calculating reference evapotranspiration are studied and calibrated (Priestley-Taylor, Makkink, Hargreaves, Turc, Jensen-Haise). These methods use temperature, T, and solar radiation, Rs, to calculate evapotranspiration. Evapotranspiration is calculated for all the days of the 2005/06 hidrological year at the Divor meteorological station. The results are compared to, and calibrated against, the Penman-Monteith method. The best results are obtained by the Priestley-Taylor and Jensen-Haise methods. Calibration coefficients are also calculated for all five methods, so that the results can be as close as possible to those produced by the Penman-Monteith method

Drip irrigation using a PLC based adaptive irrigation system

Most of the water used by man goes to irrigation. A major part of this water is used to irrigate small plots where it is not feasible to implement full-scale Evapotranspiration based irrigation controllers. During the growth season crop water needs do not remain constant and varies depending on the canopy, growth stage and climate conditions such as temperature, wind, relative humidity and solar radiation. Thus, it is necessary to find an economic irrigation controller that can adapt the daily water application to the plant needs. The dramatic development of Programmable Logic Controllers, PLCs, and their rather affordable price has made it possible to use them as stand-alone irrigation controllers. In this paper a PLC is used to adapt the daily irrigation amount to actual ETc, using a Hargreaves-Samani type equation. This equation only requires temperature values to calculate Evapotranspiration. Once the ETc is calculated, then the PLC manages the irrigation according to the characteristics of the field, the irrigation equipment and the growth stage of the crop. First year results are very encouraging and indicate a 12% saving in irrigation water. It was also found that heat flux form the soil can influence canopy temperature.The development of this study was funded by the Fundação para a Ciência e a Tecnologia (FCT) research project PTDC/AGR-AAM/81271/2006: “Desenvolvimento dum controlador de rega adaptativo, autónomo e automático”