River Styles and stream power analysis reveal the diversity of fluvial morphology in a Philippine tropical catchment

Availability of data and materials: Following review, all GIS datasets will be made available through the NERC data repository.Copyright © The Authors 2022. Characterisation of hydromorphological attributes is crucial for effective river management. Such information is often overlooked in tropical regions such as the Philippines where river management strategies mainly focus on issues around water quality and quantity. We address this knowledge gap using the River Styles Framework as a template to identify the diversity of river morphodynamics. We identify eight distinct River Styles (river types) in the Bislak catchment (586 km2) in the Philippines, showing considerable geomorphic diversity within a relatively small catchment area. Three River Styles in a Confined valley setting occupy 57% of the catchment area, another three in a partly confined valley setting occupy 37%, and two in the remaining 6% are found in a laterally unconfined valley setting. Five characteristic downstream patterns of River Styles were identified across the catchment. We observe that variation in channel slope for a given catchment area (i.e., total stream power) is insufficient to differentiate between river types. Hence, topographic analyses should be complemented with broader framed, catchment-specific approaches to river characterisation. The outputs and understandings from the geomorphic analysis of rivers undertaken in this study can support river management applications by explicitly incorporating understandings of river diversity and dynamics. This has the potential to reshape how river management is undertaken, to shift from reactive, engineering-based approaches that dominate in the Philippines, to more sustainable, ecosystem-based approaches to management.Department of Science and Technology—Philippine Council for Industry, Energy and Emerging Technology Research and Development (DOST-PCIEERD)—NERC Newton Fund grant (NE/S003312); Global Challenges Research Fund (SFC-GCRF) grant (2019)

Confined and mined: anthropogenic river modification as a driver of flood risk change

Abstract Rivers are often confined by structures and subjected to aggregate mining. In dynamic rivers, these interventions cause changes to riverbed and bank topography that potentially cause changes in hydraulics and flood risk. Repeat, system-scale, high-resolution topographic surveys of the gravel-bed Bislak River, the Philippines, are used to quantify annual morphological change and, using two-dimensional hydraulic modelling, to simulate changes to flood risk. Aggregate mining exports sediment and creates pitted topography, and embankments cause both deeper channels and disconnect the river from its floodplain. The consequently increased channel capacity reduces flood risk, with up to a 5% decrease in inundated areas for 10- to 100-year return periods. Sediment deprivation also increases bed shear stress that can induce scour, infrastructure damage and increased flood impacts. Rising global floodplain populations and increasing demand for aggregate ensure that sustainably managing geomorphologically dynamic rivers to support floodplain development and mitigate flood impacts remains a pertinent challenge.</jats:p

Big data show idiosyncratic patterns and rates of geomorphic river mobility

Data availability: The locational probability data generated in this study have been deposited in the NERC Environmental Information Data Centre (EIDC) along with supporting documentation (https://doi.org/10.5285/a2bcc66e-4dcc-4ed1-897d-cdf36dde246d).Code availability: Google Earth Engine and MATLAB codes for processing the locational probability data have been deposited in the NERC Environmental Information Data Centre (EIDC) along with supporting documentation (https://doi.org/10.5285/a2bcc66e-4dcc-4ed1-897d-cdf36dde246d).Supplementary information is available online at: https://www.nature.com/articles/s41467-025-58427-9#Sec14 .Big data present unprecedented opportunities to test long-standing theories regarding patterns and rates of geomorphic river adjustments. Here, we use locational probabilities derived from Landsat imagery (1988-2019) to quantify the dynamics of 600 km2 of riverbed in 10 Philippine catchments. Analysis of lateral adjustments reveals spatially non-uniform variability in along-valley patterns of geomorphic river mobility, with zones of relative stability interspersed with zones of relative instability. Hotspots of mobility vary in magnitude, size and location between catchments. We could not identify monotonic relationships between local factors (active channel width, valley floor width and confinement ratio) and mobility. No relation between the channel pattern type and rates of adjustment was evident. We contend that satellite-derived locational probabilities provide a spatially continuous dynamic metric that can help unravel and contextualise forms and rates of geomorphic river adjustment, thereby helping to derive insights into idiosyncrasies of river behaviour in dynamic landscapes.This research was undertaken as part of a Natural Environment Research Council (NERC) and Department of Science and Technology - Philippine Council for Industry, Energy and Emerging Technology Research and Development (DOST-PCIEERD) – Newton Fund grant NE/S003312/1

National-scale geodatabase of catchment characteristics in the Philippines for river management applications

Data Availability: The ArcGIS web-application for interactively displaying the national-scale geodatabase is available here: https://glasgow-uni.maps.arcgis.com/apps/webappviewer/index.html?id=a88b9ca0919f4400881eab4a26370cee. Supporting datasets are available here: http://dx.doi.org/10.5525/gla.researchdata.1396. Supporting datasets include: (1) GIS shapefiles with river catchment properties; (2) GIS shapefiles with stream network properties; (3) spreadsheets containing the complete set of morphometric and topographic characteristics (n = 91); and, (4) example MATLAB code and topographic data to replicate the analysis for a selected catchment. The supporting datasets will also be uploaded to the Natural Environment Research Council (NERC) Environmental Information Data Centre.Copyright: © 2023 Boothroyd et al. Quantitative descriptions of stream network and river catchment characteristics provide valuable context for enabling geomorphologically-informed sustainable river management. For countries where high-quality topographic data are available, there are opportunities to enable open access availability of baseline products from systematic assessment of morphometric and topographic characteristics. In this study, we present a national-scale assessment of fundamental topographic characteristics of Philippine river systems. We applied a consistent workflow using TopoToolbox V2 to delineate stream networks and river catchments using a nationwide digital elevation model (DEM) acquired in 2013 and generated through airborne Interferometric Synthetic Aperture Radar (IfSAR). We assessed morphometric and topographic characteristics for 128 medium- to large-sized catchments (catchment area > 250 km2) and organised the results in a national-scale geodatabase. The dataset realises the potential of topographic data as part of river management applications, by enabling variations in hydromorphology to be characterised and contextualised. The dataset is used to reveal the diversity of stream networks and river catchments in the Philippines. Catchments have a continuum of shapes (Gravelius compactness coefficient ranges from 1.05 to 3.29) with drainage densities that range from 0.65 to 1.23 km/km2. Average catchment slope ranges from 3.1 to 28.1° and average stream slope varies by more than an order of magnitude from 0.004 to 0.107 m/m. Inter-catchment analyses show the distinctive topographic signatures of adjacent river catchments; examples from NW Luzon highlight topographic similarity between catchments whereas examples from Panay Island shown marked topographic differences. These contrasts underline the importance of using place-based analyses for sustainable river management applications. By designing an interactive ArcGIS web-application to display the national-scale geodatabase, we improve data accessibility and enable users to freely access, explore and download the data (https://glasgow-uni.maps.arcgis.com/apps/webappviewer/index.html?id=a88b9ca0919f4400881eab4a26370cee). The national-scale geodatabase provides a baseline understanding of fundamental topographic characteristics in support of varied geomorphological, hydrological and geohazard susceptibility applications.This research was undertaken as part of a Natural Environment Research Council (NERC) and Department of Science and Technology - Philippine Council for Industry, Energy and Emerging Technology Research and Development (DOST-PCIEERD) – Newton Fund grant NE/S003312. RDW and TBH are also grateful to NERC grant NE/W006871/1

Livelihood and vulnerability in the wake of Typhoon Yolanda: lessons of community and resilience

Livelihood strategies that are crafted in ‘extra-ordinary’ post-disaster conditions should also be able to function once some semblance of normalcy has resumed. This article aims to show that the vulnerability experienced in relation to Typhoon Yolanda was, and continues to be, directly linked to inadequate livelihood assets and opportunities. We examine the extent to which various livelihood strategies lessened vulnerability post-Typhoon Yolanda and argue that creating conditions under which disaster survivors have the freedom to pursue sustainable livelihood is essential in order to foster resilience and reduce vulnerability against future disasters. We offer suggestions to improve future relief efforts, including suggestions made by the survivors themselves. We caution against rehabilitation strategies that knowingly or unknowingly, resurrect pre-disaster vulnerability. Strategies that foster dependency, fail to appreciate local political or ecological conditions or undermine cooperation and cohesion in already vulnerable communities will be bound to fail. Some of the livelihood strategies that we observed post-Typhoon Yolanda failed on some or all of these points. It is important for future policy that these failings are addressed

The risk of burden shifting from embodied carbon calculation tools for the infrastructure sector

The infrastructure sector is associated with a large proportion of total greenhouse gas emissions, including the emissions from the production of materials and the construction of infrastructure assets, as well as use phase and end of life emissions. Largely due to the direct control the sector has over pre-use phase emissions, a number of carbon calculator tools for the sector focus exclusively on these sources. However, a recognised limitation with considering only parts of the whole life cycle is the risk of burden shifting, e.g. reducing material input emissions but increasing emissions in the use or end of life phases. Despite recognition of this problem in principle, there are very few empirical studies which explore the risk and impacts of burden shifting within the infrastructure sector, or construction sector more broadly. This paper addresses the gap in the existing literature by exploring the possibility of burden shifting occurring due to the use of an embodied carbon calculator. The analysis shows that burden shifting will occur for some actions aimed at reducing embodied carbon, but not others, e.g. in Decision Case 4, an initial saving of 4,500 tCO2e during construction was offset by increased use phase emissions in as little as four years. In order to support the use of embodied carbon calculators we propose a number of heuristics to identify cases where burden shifting may occur, and therefore where a whole-of-life assessment is needed. We also suggest that the infrastructure sector is in a learning process in terms of carbon measurement, and that over time there should be a transition from embodied carbon calculators to whole-of-life assessment, and from whole-of-life attributional life cycle assessment to consequential carbon assessment methods

Medical Language For Modern Health Care

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