Groundwater Recharge, Evapotranspiration and Surface Runoff Estimation Using WetSpass Modeling Method in Illala Catchment, Northern Ethiopia

Hydrometeorological information is important in planning and management of natural resources. The northern Ethiopia in general and Illala sub-basin in particular is lacking reliable information with regard to groundwater recharge, evapotranspiration and surface runoff. The main objective of the study is to estimate the distributed groundwater recharge, surface runoff and evapotranspiration amount of Illala sub basin using WetSpass modeling method. Long term mean hydrometeorological data and physical characteristics of the catchment such as land use/land cover, soil type, topography, groundwater level and slope are used as an input to the model. The mean annual groundwater recharge, evapotranspiration and runoff were found to be 66, 440 and 40mm respectively. Accordingly, recharge accounts for 12% of the precipitation while the rest 81% and 7% becomes evapotranspiration and surface runoff respectively. The study area is characterized by low groundwater recharge due to the presence of high evapotranspiration rate associated with high temperature, dry wind, low rainfall and relative humidity though it is a little bit large compared to some parts of the northern Ethiopia.Keywords: Groundwater, WetSpass, Recharge, Illala, Catchment, Tigray, Ethiopi

How Tigrayan farmers turn land use rights (and their lack) into access to farm land

Land tenure in Ethiopia is much-discussed in literature. Most recent studies on rural land deal with legal land use rights and formal tenure security. They usually touch upon a number of formal and informal entitlement exchange mechanisms superimposed on the legal distribution of arable land, but do not go into detail on these superimpositions as practiced and experienced by smallholder farmers nor on the complexity of outcomes they generate in terms of access to land. In-depth qualitative research in one sub-district of the Degua Temben district in Tigray (Northern Ethiopia) reveals the latter to be very relevant as local farmers' conceptions of success and failure are based on access to the benefits of own as well as other people's land. In other words, for farmers in the study area year-to-year materialisation of access to land for cultivation is as much an issue as having legal land use rights, having them secured and having them registered. First, we unravel the current distribution of legal land use rights in the sub-district under study, being the intersection of a number of policy measures on different administrative levels from 1990 until now. Indeed recent land policy decisions in the study area on the one hand are characterised by high levels of decentralisation (i.e. land is divided and administered at the local level), but on the other hand are restricted by strong boundary conditions stated at both the national and the regional level. Secondly, farmers' responses to this "legal" outcome, resulting in "real" access to farm land and its products, are explored. Farmers' initiatives transforming land use rights (or their lack, as land poverty is substantial) are shown to be extremely diverse and to give rise to an alternative distribution of land. Farming households in the research area on average use and enjoy (part of) the benefits of more plots than they have formal user rights on, and their land exchange mechanisms can either have a mitigating or an amplifying influence on land inequality.status: publishe

SARS-CoV-2 vaccination modelling for safe surgery to save lives: data from an international prospective cohort study

Background: Preoperative SARS-CoV-2 vaccination could support safer elective surgery. Vaccine numbers are limited so this study aimed to inform their prioritization by modelling. Methods: The primary outcome was the number needed to vaccinate (NNV) to prevent one COVID-19-related death in 1 year. NNVs were based on postoperative SARS-CoV-2 rates and mortality in an international cohort study (surgical patients), and community SARS-CoV-2 incidence and case fatality data (general population). NNV estimates were stratified by age (18-49, 50-69, 70 or more years) and type of surgery. Best- and worst-case scenarios were used to describe uncertainty. Results: NNVs were more favourable in surgical patients than the general population. The most favourable NNVs were in patients aged 70 years or more needing cancer surgery (351; best case 196, worst case 816) or non-cancer surgery (733; best case 407, worst case 1664). Both exceeded the NNV in the general population (1840; best case 1196, worst case 3066). NNVs for surgical patients remained favourable at a range of SARS-CoV-2 incidence rates in sensitivity analysis modelling. Globally, prioritizing preoperative vaccination of patients needing elective surgery ahead of the general population could prevent an additional 58 687 (best case 115 007, worst case 20 177) COVID-19-related deaths in 1 year. Conclusion: As global roll out of SARS-CoV-2 vaccination proceeds, patients needing elective surgery should be prioritized ahead of the general population