This report provides the results of Work Package 7 (WP7). WP7 focuses on the integration of methodological approaches across scales and provides guidelines for policy development in the context of sediment and large wood management. Two guidelines with methodological explanations and good practice examples are provided as expected output of this WP. The contents of the first guideline are the estimation of sediment budget and scenarios determination to be used for flood mitigation in Alpine basins. The identification of morphological impacts related to hydropower plants and gravel extraction is dealt with in the second guideline. Sediment budget analysis consists in the evaluation of fluxes, sources and sinks from different processes. Different factors influence sediment and wood transport and need to be carefully evaluated within specific spatial and temporal scales. Correct approaches and tools to estimate sediment and wood budget that consider the river reach of interest, with its specific basin and channel processes in order to evaluate the availability of transportable material are focused on in the first guideline. Sediment mobility ranges from bedload (mountain and foothill reaches) to hyperconcentrated and debris flows (mountain reaches). Wood, is instead mainly delivered by floating, bank erosion processes and landslides. Different scenarios concerning the interaction with structures, sediment continuity, torrent-control strategies for sediment erosion and debris flows in relation to an efficient structure design are dealt with in the second part of the first guideline. In addition, sediment retention management and policy are discussed to highlight recent trends in the regulatory instruments. Dams represent one of the most significant human interventions in the hydrological cycle. Dams and reservoirs are built and operated for several purposes such as power generation, flood protection, drinking water or agricultural water supply, recreation, fishing, and others. The construction of a dam results in discontinuities to the river continuum; their presence can strongly interact with the sediment continuity from the upper parts of the basin to the area downstream of dams. While the 20th century focused on dam construction, the 21st will focus on sustaining the function of existing infrastructure as it becomes increasingly affected by sedimentation. The objective of sediment management is to manipulate the river-reservoir system to achieve sediment balance while retaining as much beneficial storage as possible, and minimizing environmental impacts and socioeconomic costs. Procedures for the identification of morphological impacts related to hydropower plants and gravel extraction are provided in the second guideline. The first part of the guideline is focused on reservoir sediment management plans and proposals for management improvement. Indicators for the evaluation of fluviomorphological impacts due to sediment removal or sediment supply reduction are presented in the second part of this guideline. Finally, recommendations and implications for policy, practitioners and for research are provided for both guidelines.
Sediment management
Brardinoni F;Perina E;Cavalli M;
2015
Abstract
This report provides the results of Work Package 7 (WP7). WP7 focuses on the integration of methodological approaches across scales and provides guidelines for policy development in the context of sediment and large wood management. Two guidelines with methodological explanations and good practice examples are provided as expected output of this WP. The contents of the first guideline are the estimation of sediment budget and scenarios determination to be used for flood mitigation in Alpine basins. The identification of morphological impacts related to hydropower plants and gravel extraction is dealt with in the second guideline. Sediment budget analysis consists in the evaluation of fluxes, sources and sinks from different processes. Different factors influence sediment and wood transport and need to be carefully evaluated within specific spatial and temporal scales. Correct approaches and tools to estimate sediment and wood budget that consider the river reach of interest, with its specific basin and channel processes in order to evaluate the availability of transportable material are focused on in the first guideline. Sediment mobility ranges from bedload (mountain and foothill reaches) to hyperconcentrated and debris flows (mountain reaches). Wood, is instead mainly delivered by floating, bank erosion processes and landslides. Different scenarios concerning the interaction with structures, sediment continuity, torrent-control strategies for sediment erosion and debris flows in relation to an efficient structure design are dealt with in the second part of the first guideline. In addition, sediment retention management and policy are discussed to highlight recent trends in the regulatory instruments. Dams represent one of the most significant human interventions in the hydrological cycle. Dams and reservoirs are built and operated for several purposes such as power generation, flood protection, drinking water or agricultural water supply, recreation, fishing, and others. The construction of a dam results in discontinuities to the river continuum; their presence can strongly interact with the sediment continuity from the upper parts of the basin to the area downstream of dams. While the 20th century focused on dam construction, the 21st will focus on sustaining the function of existing infrastructure as it becomes increasingly affected by sedimentation. The objective of sediment management is to manipulate the river-reservoir system to achieve sediment balance while retaining as much beneficial storage as possible, and minimizing environmental impacts and socioeconomic costs. Procedures for the identification of morphological impacts related to hydropower plants and gravel extraction are provided in the second guideline. The first part of the guideline is focused on reservoir sediment management plans and proposals for management improvement. Indicators for the evaluation of fluviomorphological impacts due to sediment removal or sediment supply reduction are presented in the second part of this guideline. Finally, recommendations and implications for policy, practitioners and for research are provided for both guidelines.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.