Abstract:The development of a decision support system (DSS) to inform policy making has been progressing rapidly. This paper presents a generic framework and the development steps of a decision tool prototype of geographic information systems (GIS)-based decision support system of river health diagnosis (RHD-DSS). This system integrates data, calculation models, and human knowledge of river health status assessment, causal factors diagnosis, and restoration decision making to assist decision makers during river restoration and management in Zhejiang Province, China. Our RHD-DSS is composed of four main elements: the graphical user interface (GUI), the database, the model base, and the knowledge base. It has five functional components: the input module, the database management, the diagnostic indicators management, the assessment and diagnosis, and the visual result module. The system design is illustrated with particular emphasis on the development of the database, model schemas, diagnosis and analytical processing techniques, and map management design. Finally, the application of the prototype RHD-DSS is presented and implemented for Xinjiangtang River of OPEN ACCESSWater 2014, 6 3137Haining County in Zhejiang Province, China. This case study is used to demonstrate the advantages gained by the application of this system. We conclude that there is great potential for using the RHD-DSS to systematically manage river basins in order to effectively mitigate environmental issues. The proposed approach will provide river managers and designers with improved insight into river degradation conditions, thereby strengthening the assessment process and the administration of human activities in river management.

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Monitoring evapotranspiration and surface energy fluxes over a range of spatial and temporal scales is crucial for many agroenvironmental applications. Different remote sensing based energy balance models have been developed, to estimate evapotranspiration at both field and regional scales. In this contribution, METRIC (Mapping EvapoTranspiration at high Resolution with Internalized Calibration), has been applied for the estimation of actual evapotranspiration in the Ghriss plain in Mascara (western Algeria), a semiarid region with heterogeneous surface conditions. Four images acquired during 2001 and 2002 by the Landsat-7 satellite were used. The METRIC model followed an energy balance approach, where evapotranspiration is estimated as the residual term when net radiation, sensible and soil heat fluxes are known. Different moisture indicators derived from the evapotranspiration were then calculated: reference evapotranspiration fraction, Priestley-Taylor parameter and surface resistance to evaporation. The evaluation of evapotranspiration and surface energy fluxes are accurate enough for the spatial variations of evapotranspiration rather satisfactory than sophisticated models without having to introduce an important number of parameters in input with difficult accessibility in routine. In conclusion, the results suggest that METRIC can be considered as an operational approach to predict actual evapotranspiration from agricultural areas having limited amount of ground information. Keywords: evapotranspiration, remote sensing, METRIC, energy balance, Landsat. Estimativa da Evapotranspiração e Fluxos de Energia de Superfície Usando a Imagem Landsat-7 Enhanced Thematic Mapper Plus em um AgrosistemaAemi-árido no Noroeste da Argélia ResumoO monitoramento dos fluxos de energia e da evapotranspiração em diferentes escalas espaciais e temporais é crucial para muitas aplicações agroambientais. Diferentes modelos baseados no sensoriamento remoto têm sido desenvolvidos para estimativa da evapotranspiração tanto em escala local como em largas escalas. Neste contexto, o METRIC (Mapping EvapoTranspiration at high Resolution with Internalized Calibration) tem sido aplicado para a estimative da evapotranspiração em "Ghriss plain" em Mascara, uma região semiárida no noroeste da Argélia com condições e superfícies heterogêneas. Quatro imagens adquiridas durante 2001 a 2002 com o sensor Landsat-7 ETM+ foram usadas. O modelo METRIC computa o balanço de energia onde a evapotranspiração é estimada como resíduo quando o saldo de radiação e os fluxos de calor sensível e no solo são conhecidos. Diferentes indicadores de umidade derivados da evapotranspiração foram então calculados: a fração da evapotranspiração de referência, o parâmetro Priestley-Taylor e a resistência da superfície à evapotranspiração. As avaliações da evapotranspiração e dos fluxos de energia foram suficientemente precisas para detecção das variações espaciais da evapotranspiração, sendo mais satisfatórias que aquelas provenientes de modelos sofisticados sem...

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A curved riparian zone can create highly complex flow patterns that have a great effect on erosion, pollutant transport, surface water-groundwater exchange and habitat qualities. The small-disturbance theory has been applied to derive the analytical solutions of pressure distributions along a sinusoidal riverbank. Experiments have also been performed to test the hydrodynamic and geomorphic effects on pressure distribution and to verify the applicability of the derived expressions. The derived expressions were simple, accurate and agreed remarkably well with experimental results for the riparian banks with a low degree of curvature. On the contrary, when a riparian bank had a high degree of curvature, these expressions applying the approach of small-disturbance, could not effectively estimate the pressure distributions for a complex bank boundary or complex flow conditions. Moreover, sensitive analysis has indicated that the disturbed pressures along the riparian banks increased with increasing Froude number Fr, as well as the ratio of bank amplitude to wavelength a/λ. However, a/λ has been found to have more significant influence on pressure variation in subcritical flow.