Slapis Archives - climateservices.it CNR-IBE

A streamlined flood-specific evaluation framework: Assessing African riverine early warning systems

Vieri Tarchiani — Fri, 26 Jun 2026 08:38:28 +0000

Intense hydrological events are rising across Africa, increasing flood risks. Flood Early Warning Systems (FEWS) are internationally acknowledged as fundamental tools for risk reduction and management. Their effectiveness depends on the integrated and balanced development of all essential components -risk knowledge, monitoring and forecasting, dissemination and communication, preparedness and response-yet their integration across operational systems is poorly documented.

This study develops a flood-specific evaluation framework adapted from the UNDRR-WMO Multi-Hazard Early Warning System Custom Indicators (MHEWS-CI), reducing its 53 indicators to 25 through thematic consolidation and flood-specific adaptation. The framework is applied to assess 19 African riverine FEWS using publicly available documentation, as a proof-of-concept. Each indicator is assessed through a recognition-based approach: documented system functionalities are matched against three predefined development stages (absent, basic, advanced), lightning the reporting burden of MHEWS-CI. Scores are compared to illustrate relationships between system characteristics and development of components.

Results reveal imbalances: 74% of systems demonstrate advanced monitoring and forecasting, but only 5% achieve advanced response capabilities. Web architectures and hydrological models favour monitoring and forecasting but show no corresponding advantage in response integration. Hybrid systems combining model forecasting with community engagement achieve the highest overall scores, suggesting that optimal development requires balancing technical sophistication with a participatory approach.

These patterns may reflect institutional factors -governance fragmentation and insufficient operational integration-rather than causal effects of system characteristics. The framework delivers a streamlined, replicable instrument for insightful FEWS assessment, successfully corroborating prior research and supporting evidence-based identification of operational gaps and investment prioritisation.

The post A streamlined flood-specific evaluation framework: Assessing African riverine early warning systems appeared first on climateservices.it CNR-IBE.

Dataset on Flood Risk Along the Niger River Upstream of Niamey

Vieri Tarchiani — Wed, 10 Jun 2026 14:31:38 +0000

Knowledge of river flood risk in semiarid rural areas is often based on outdated, low-resolution geoinformation. Consequently, identification of exposed settlements, assets and risk-reduction measures remains challenging. This dataset provides up-to-date, fine-grained information for a rural area spanning 931 km² that is exposed to flooding from the Niger River and the Karma Wadi. The dataset includes information on (i) areas exposed to the two flood types that characterise the river’s hydrological regime and flash floods from the wadi, (ii) flood-prone crops, buildings and (iii) measures for risk treatment. Discharge data, a 4 m horizontal-resolution digital elevation model, and two-dimensional hydraulic modelling with BASEMENT were used to identify flood-prone areas. Visual interpretation of high-resolution satellite imagery in Google Earth, together with field inspections, enabled the identification of exposed assets. The Information System on Rural Markets of Niger and house compensation values recognised during resettlement-related works enabled asset valuation. Risk was expressed in monetary terms as the product of flood probability and expected damage. Risk-reduction measures were identified with stakeholders through a SWOT analysis and prioritised using eight criteria. The dataset can support emergency plans, flood early warning systems, rescue and recovery operations and flood risk management.

The post Dataset on Flood Risk Along the Niger River Upstream of Niamey appeared first on climateservices.it CNR-IBE.

Mapping precipitation extremes for pluvial flood risk management in the Sirba river basin, Burkina Faso

Vieri Tarchiani — Fri, 22 May 2026 10:11:30 +0000

Sahelian Africa is increasingly exposed to extreme hydrological events. Both fluvial and pluvial floods are becoming more severe and frequent, posing significant new threats to the livelihoods of local communities. To enhance resilience to floods, the development of effective operational tools for assessing risk and supporting decision-making is crucial. When it comes to pluvial floods, the first step towards this goal is to improve the understanding of extreme daily and sub-daily precipitation events and their spatial patterns in the target areas. Within the SLAPIS Project framework, this work does so for the Sirba river basin (Burkina Faso and Niger) proposing a methodology to address the challenges posed by the scarcity of hydrological data typical of the Sahel region. First, it was assessed how well gridded precipitation products (ERA5, TRMM, TAMSAT) match observed rainfall records. Then, bias correction of selected datasets was performed and tested to evaluate its reliability when spatially interpolated through the whole basin. The Metastatistical Extreme Value Distribution was finally applied to the corrected datasets to investigate the precipitation extremes exploiting the bulk of the available data, unlike classical extreme value analysis, which relies on only a small subset of the data. This procedure resulted in the production of extreme daily and sub-daily precipitation maps with enhanced accuracy and robustness, providing novel information on events that can cause pluvial flooding at the settlement scale. The methodology adopted in this study could be applied to other Sahelian basins where enhanced knowledge of extreme precipitation magnitudes and patterns is needed.

The post Mapping precipitation extremes for pluvial flood risk management in the Sirba river basin, Burkina Faso appeared first on climateservices.it CNR-IBE.

DEM Generation from Multi-View Satellite Images in Sub-Sahel Region

Web Editor — Fri, 13 Jun 2025 07:37:12 +0000

Floods are causing a significant loss of human lives and valuable resources in West Africa. In particular, Niger and Burkina Faso were highly affected areas in past years. In order to predict flood, an accurate Digital elevation model (DEM) is required for flood mapping. At the studied area in Niger, up to this date, the LiDAR DEMs are scarcely available, and the only available DEMs are global DEMs like global SRTM DEMs with a resolution of 10m. These global DEMs are not accurate enough to be used for flood mapping. So, in this context, this study investigates the potential of multidate, multi-view stereo pairs PlanetScope images for the generation of DEM. Three DEMs were generated from images with slightly different view angles to see the effect of view angles of images on 3D modelling. One of the DEM generated by PlanetScope images was compared with DEM generated by high-resolution drone imagery and shows the normalized Median of Absolute Deviation (NMAD) of the elevation differences of 10m. Results show that planetScope images are useful assets for generating multiple DEMs due to their high temporal resolution. Such DEMs could be extremely useful for studying dynamic phenomena or monitoring disaster events like floods.

Keywords: Remote Sensing, DEM Generation, Cubesat Satellites, Stereo-Modelling, 3D Modelling

The post DEM Generation from Multi-View Satellite Images in Sub-Sahel Region appeared first on climateservices.it CNR-IBE.

Hydrological Web Services for Operational Flood Risk Monitoring and Forecasting at Local Scale in Niger

Web Editor — Tue, 05 Apr 2022 15:19:17 +0000

Emerging hydrological services provide stakeholders and political authorities with useful and reliable information to support the decision-making process and develop flood risk management strategies. Most of these services adopt the paradigm of open data and standard web services, paving the way to increase distributed hydrometeorological services’ interoperability. Moreover, sharing of data, models, information, and the use of open-source software, greatly contributes to expanding the knowledge on flood risk and to increasing flood preparedness. Nevertheless, services’ interoperability and open data are not common in local systems implemented in developing countries. This paper presents the web platform and related services developed for the Local Flood Early Warning System of the Sirba River in Niger (SLAPIS) to tailor hydroclimatic information to the user’s needs, both in content and format. Building upon open-source software components and interoperable web services, we created a software framework covering data capture and storage, data flow management procedures from several data providers, real-time web publication, and service-based information dissemination. The geospatial infrastructure and web services respond to the actual and local decision-making context to improve the usability and usefulness of information derived from hydrometeorological forecasts, hydraulic models, and real-time observations. This paper presents also the results of the three years of operational campaigns for flood early warning on the Sirba River in Niger. Semiautomatic flood warnings tailored and provided to end-users bridge the gap between available technology and local users’ needs for adaptation, mitigation, and flood risk management, and make progress toward sustainable development goals.

The post Hydrological Web Services for Operational Flood Risk Monitoring and Forecasting at Local Scale in Niger appeared first on climateservices.it CNR-IBE.

Community and Impact Based Early Warning System for Flood Risk Preparedness: The Experience of the Sirba River in Niger

Vieri Tarchiani — Tue, 30 Jun 2020 11:59:37 +0000

Floods have recently become a major hazard in West Africa (WA) in terms of both their magnitude and frequency. They affect livelihoods, infrastructure and production systems, hence impacting on Sustainable Development (SD). Early Warning Systems (EWS) for floods that properly address all four EWS components, while also being community and impact‐based, do not yet exist in WA. Existing systems address only the main rivers, are conceived in a top‐down manner and are hazard‐centered. This study on the Sirba river in Niger aims to demonstrate that an operational community and impact‐based EWS for floods can be set up by leveraging the existing tools, local stakeholders and knowledge. The main finding of the study is that bridging the gap between topdown and bottom‐up approaches is possible by directly connecting the available technical capabilities with the local level through a participatory approach. This allows the beneficiaries to define the rules that will develop the whole system, strengthening their ability to understand the information and take action. Moreover, the integration of hydrological forecasts and observations with the community monitoring and preparedness system provides a lead time suitable for operational decision‐making at national and local levels. The study points out the need for the commitment of governments to the transboundary sharing of flood information for EWS and SD.

The post Community and Impact Based Early Warning System for Flood Risk Preparedness: The Experience of the Sirba River in Niger appeared first on climateservices.it CNR-IBE.