Mapping and Managing Organization Objectives: A Case Study of the Alto Maipo Hydroelectric Project in Chile

This study presents a process that uses the method of alliances, conflicts, tactics, objectives, and recommendations (MACTOR) to inform integrated water resources management (IWRM) strategies for complex, multiorganization hydroelectric projects. This process is applied to the Alto Maipo Hydroelectric Project (AMHP) in Chile. The process enabled qualitative and quantitative insight on the interconnected aspects of alignment and conflict between AMHP organizations by mapping the battlefield on which they converge or diverge based on their organizational objectives and relative levels of influence. Study findings reveal environmental protection and water provision as the core objectives around which conflicts center. Study findings also point to a nuanced power struggle between state and local organizations that undermines project productivity. Project recommendations focus on improving communication and collaboration between aligned yet siloed organizations and on improving the mechanisms for information flow and advocacy for the local community and governmental organizations. These findings demonstrate the utility of the MACTOR approach—as it is applied within the proposed process—as a way to inform IWRM strategies for multiorganization hydroelectric projects from a systems perspectiv

Detecting and quantifying hydromorphology changes in a chilean river after 50 years of dam operation

This study identifies and characterizes hydromorphological changes along the Rapel River downstream of the first large dam built in Chile (1968). A hydromorphological analysis is carried out to assess changes on the hydrological flow regime, bed sediments, and fluvial morphology along a 19 km river reach. Results classify current global hydrological quality as “Moderate” (according to the Indicator for Hydrological Alteration in RIverS, IAHRIS), however specific indicators within this classification scheme identified quality as “Poor”. The morphological quality decreased from “Very Good” to “Good” (assessed by the Morphological Quality Index, MQI). Changes in the planform were particularly intense during the post dam period when intensive lateral mobility occurred, with the corresponding loss of secondary river branches, and with generation of straighter and regular river sections with presence of an armor layer observed along the entire river reach. Between 1991 and 2015 channel stabilization with less lateral mobility was observed, which thought to be associated with the river new equilibrium trend. River width, sinuosity and braiding index changed at different rates along the studied river reach. Our investigation demonstrates that the Rapel River experienced changes differently than those described in the literature given its lower gradient and hydraulic interaction with the Pacific Ocean

Evaluacion del comportamiento de seis cultivares de cebollas (Allium cepa L.) para cosecha temprana en Villa Alegre - VII Region.

Resumen (Spanish, English)68 p.Se realizó una investigación en cebolla de día corto (Allium cepa L.) durante la temporada 2002 - 2003 en la localidad de Villa Alegre, VII región, Chile (36033'19.1"Latitud Sur y 350 W40,5- Longitud Oeste), con el objetivo de evaluar el comportamiento productivo, rendimiento total, comercial y desecho, y la calidad comercial a la cosecha, junto con determinar la(s) mejor(es) época(s) de plantación, en un diseño de bloques al azar con cuatro repeticiones, en tres épocas de plantación (5 de abril, 30 de abril y 19 de mayo). Los rendimientos totales mostraron diferencias estadísticamente significativas entre los tratamientos en la época 1 variando entre 25,94 y 35,34 ton/ha. La época 11 no presentó diferencias estadísticamente significativas en el rendimiento total, variando entre 29,13 y 36,20 ton/ha, y en la época Ill, los tratamientos no difieren estadísticamente entre ellos. Los rendimientos comerciales obtenidos se diferenciaron significativamente entre los cultivares siendo los híbridos Mercedes y Canaria Dulce los que presentaron mayores valores respecto al resto de los tratamientos, con valores de 16,47 y 15,01 ton/ha respectivamente. La segunda época fue la que mostró mejores resultados tanto en rendimiento como en calidad de bulbo al momento de cosecha. La época Ill de plantación no presentó buenos rendimientos respecto a la segunda. No se encontraron diferencias significativas con relación al contenido de materia seca el cual en la época 1 fluctuó entre 6,8 y 7,8%, en la segunda entre 6,0 y 8,0%, mientras que en la última varió entre 6,8 y 8,2%, dichos valores están dentro del esperado. Respecto a ]a cantidad de sólidos solubles ('Brix) en las tres épocas de plantación no hay diferencias significativas entre los cultivares de cebolla. Estos presentaron valores entre 7.7 y 8.7° Brix en la primera época, 8.4 y 9.2 en la segunda y.8.8 y 10° Brix en la tercera

Automatic Segmentation of Water Bodies Using RGB Data: A Physically-Based approach

This project presents code, data, and analyses of the manuscript entitled "Automatic Segmentation of Water Bodies Using RGB Data: A Physically-Based approach

Influence of Dam Breach Parameter Statistical Definition on Resulting Rupture Maximum Discharge

However rare, dam breach occurrences are recently reported and associated with significant damage to life and property. The rupture of the structural dam wall generates severe flow rates that exceed spillway capacity consequently generating unprecedented flooding scenarios. The present research aims to assess the influence of the dam breach statistical configuration on the most relevant parameters to predict the rupture maximum discharge (RMD). McBreach© software was used to provide the necessary inputs for the operation of the HEC-RAS dam breach module. McBreach© automates the process of batch mode simulations providing a Monte Carlo approach to characterize the breach parameters stochastically. Thus, a sensitivity analysis was performed to identify the most influential breach parameters, followed by an uncertainty assessment regarding their statistical definition of the resultant RMD. Analysis showed that the overtopping failure mode discharges are most sensitive to the breach formation time (tf) parameter, followed by the final height breach (Inv) and the final width of the breach (B), which combined are responsible for 85% of the rupture’s maximum discharge. Further results indicated highly variable RMD magnitudes (up to 300%) depending on the breach parameter’s statistical definition (i.e., probability density function and associated statistical parameters). The latter significantly impacts the estimated flood risk associated with the breach, the flood zone delimitation, preparation of emergency action plans (EAP) and scaling of future dam projects. Consequently, there is a plausible need for additional investigations to reduce this uncertainty and, therefore, the risk associated with it

Data

Dat

Influence of Dam Breach Parameter Statistical Definition on Resulting Rupture Maximum Discharge

However rare, dam breach occurrences are recently reported and associated with significant damage to life and property. The rupture of the structural dam wall generates severe flow rates that exceed spillway capacity consequently generating unprecedented flooding scenarios. The present research aims to assess the influence of the dam breach statistical configuration on the most relevant parameters to predict the rupture maximum discharge (RMD). McBreach© software was used to provide the necessary inputs for the operation of the HEC-RAS dam breach module. McBreach© automates the process of batch mode simulations providing a Monte Carlo approach to characterize the breach parameters stochastically. Thus, a sensitivity analysis was performed to identify the most influential breach parameters, followed by an uncertainty assessment regarding their statistical definition of the resultant RMD. Analysis showed that the overtopping failure mode discharges are most sensitive to the breach formation time (tf) parameter, followed by the final height breach (Inv) and the final width of the breach (B), which combined are responsible for 85% of the rupture’s maximum discharge. Further results indicated highly variable RMD magnitudes (up to 300%) depending on the breach parameter’s statistical definition (i.e., probability density function and associated statistical parameters). The latter significantly impacts the estimated flood risk associated with the breach, the flood zone delimitation, preparation of emergency action plans (EAP) and scaling of future dam projects. Consequently, there is a plausible need for additional investigations to reduce this uncertainty and, therefore, the risk associated with it

Supplementary Material

Supplementary Materia

WATER (code)

Cod

The Influence of Pool-Riffle Morphological Features on River Mixing

Accurate prediction of pollutant concentrations in a river course is of great importance in environmental management. Mathematical dispersion models are often used to predict the spatial distribution of substances to help achieve these objectives. In practice, these models use a dispersion coefficient as a calibration parameter that is calculated through either expensive field tracer experiments or through empirical equations available in the scientific literature. The latter are based on reach-averaged values obtained from laboratory flumes or simple river reaches, which often show great variability when applied to natural streams. These equations cannot directly account for mixing that relates specifically to spatial fluctuations of channel geometry and complex bed morphology. This study isolated the influence of mixing related to bed morphology and presented a means of calculating a predictive longitudinal mixing equation that directly accounted for pool-riffle sequences. As an example, a predictive equation was developed by means of a three-dimensional numerical model based on synthetically generated pool-riffle bathymetries. The predictive equation was validated with numerical experiments and field tracer studies. The resulting equation was shown to more accurately represent mixing across complex morphology than those relations selected from the literature