Assessing water deprivation at the sub-river basin scale in LCA integrating downstream cascade effects.

Physical water deprivation at the midpoint level is assessed in water-related LCIA methods using water scarcity indicators (e.g., withdrawal-to-availability and consumption-to-availability) at the river basin scale. Although these indicators represent a great step forward in the assessment of water-use-related impacts in LCA, significant challenges still remain in improving their accuracy and relevance. This paper presents a methodology that can be used to derive midpoint characterization factors for water deprivation taking into account downstream cascade effects within a single river basin. This effect is considered at a finer scale because a river basin must be split into different subunits. The proposed framework is based on a two-step approach. First, water scarcity is defined at the sub-river basin scale with the consumption-to-availability (CTA) ratio, and second, characterization factors for water deprivation (CFWD) are calculated, integrating the effects on downstream sub-river basins. The sub-river basin CTA and CFWD were computed based on runoff data, water consumption data and a water balance for two different river basins. The results show significant differences between the CFWD in a given river basin, depending on the upstream or downstream position. Finally, an illustrative example is presented, in which different land planning scenarios, taking into account additional water consumption in a city, are assessed. Our work demonstrates how crucial it is to localize the withdrawal and release positions within a river basin.

Datasets for the assessment of changes in the incidence, extents, and spatial patterns of inundations in the Cambodian Mekong Delta, based on a water level - flood link calculated from in-situ water levels, and Sentinel-derived inundation maps.

This brief contains the data needed to calculate and assess the robustness of a water level - flood link (WAFL) in the Cambodian Mekong Delta, which was used to analyze changes in the long-term behavior of Monsoon inundations in the region. The data comprises the WAFL raster (.tif) files for two zones in the delta. Zone A is located on the right bank of the Bassac River, a distributary of the Mekong. Zone B is bracketed between the Mekong River and the Bassac River. The WAFL was calculated by linking water levels measured by the Mekong River Commission (MRC) at the hydrological station in Koh Khel, with inundation maps derived from Sentinel-1 and -2 images taken between 2017 and 2021. The final WAFL raster files provides a basis for estimating inundation extents using in-situ water levels. Furthermore, this brief includes data used for the assessment of WAFL, including in-situ water level data and the extents of natural vegetation in the case study area in 1990, 2000, 2010 and 2020. The former was collected using a differential pressure logger. The latter was calculated from historical Landsat image composites. Finally, raster files representing the incidence and duration of inundations in the case study area before and after the year 2008 are provided. These were calculated based on the WAFL and the MRC water levels. For each area, before- and after-images are available, as well as a raster representing the change between the two. To simplify visualization and geographical location, shapefiles (.shp) of the study area and the location of the in-situ logger are also provided.