Alexandre Repetti

Introducing SMURF : A software system for monitoring urban functionalities

Urban land-use planning and management are in constant mutation throughout the world. With sustainability as a goal, the use of participative GIS is becoming more and more in demand. Given the willingness of local authorities to test participatory models and instruments, this paper presents an original implementation of information and communication technologies to support public participation. A system for monitoring urban functionalities (SMURF) was created for supporting participatory planning and management in African cities. The software instrument consists of a geographic database and of spatial indicators, for sharing information, editing information, and evaluating city development. To collect and update data, the model begins with the gathering of the data from each stakeholder, who, in return, gets a better knowledge of the land and a planning support tool. However, the implementation of these technologies presents several challenges: create an adapted interface, elaborate a relevant set of data and indicators, manage the data, and institutionalize the instrument. After an introductory presentation of the context and use of information technologies for the management of African cities, this paper focuses on SMURF and its components. It then shows the experimental application of the software in the city of Thies, Senegal, before concluding with a more general discussion on the relationship between technology, information, knowledge, and participation.

Toward a New Approach for Hydrological Modeling: A Tool for Sustainable Development in a Savanna Agro-System

Agriculture in Tambarga, a small, remote village in the landlocked country of Burkina Faso, is dependent on the seasonally variable local hydrology. Extreme seasonal and spatial variability of rainfall significantly impacts the livelihood of farmers, who depend mainly on rainfed agriculture. This dependence on rainfed production makes them particularly vulnerable to meteorological conditions, and they continually experience food insecurity. The groundwater is promising as storage to mitigate effects of drought. However, because of its interaction with the various hydrological components, we need to better understand all the processes to fully assess the impacts of possible solutions. Hydrological and meteorological data were collected over a two-and-a-half-year period in the catchment adjacent to the village (area = 3.5 km²) to address these issues. The field studies show that the major portion of storm runoff was generated in the upper savanna basin, while baseflow appears to be mostly originating from the downstream agricultural field. The seasonal cycle of groundwater appears to control the stream flow and therefore, the continuous flow over the entire stream occurred when the water tables became interconnected and surfaced the ground level. Additionally, this paper discusses water management scenarios (open dam, deeper wells and buried dam) for agricultural purposes using a simple and comprehensive hydrological model. Simulations based on reducing evaporation rate by keeping the water underground present a solution that could improve agricultural production, and therefore, reduce vulnerability of Tambarga’s farmers to climate change.

Application of Soil Moisture Model to Marula (Sclerocarya birrea): Millet (Pennisetum glaucum) Agroforestry System in Burkina Faso

A simple soil moisture model is developped to asses the effect of Sclero carya birrea agroforestry trees on neighboring Pennisetum glaucum plantations. Data for this model was collected using an innovative new system of small meteorological stations utilizing a wireless sensor network to transmit data in real-time to a central server. This research took place in a subcatchment of the Singou River basin near the commune of Madjoari in South Eastern Burkina Faso. Rainfall, interception, runoff, leakage, and evapotranspiration are balanced to produce values of relative soil moisture under the canopy of the agroforesty tree and in the crop system. Model successfully estimated soil moisture through the peak of the rainy season, however later in season unexplained drainage was observed. Storage was found to be heigher under the agroforesty tree.

Land management with the SMURF planning support system

Keywords: info4dourou Reference EPFL-CHAPTER-204965 Record created on 2015-02-03, modified on 2017-02-16

A DSS for Sustainable Development

This paper presents an original approach for the planning of infrastructures and resources, developed and experimented through thirteen case studies. The method is based on the linkage of the classic logistical approach with a multicriteria Decision Support System (DSS), making use of three tools: an aggregation outranking algorithm, a Geographic Information System and a graphic consultation interface. The approach is applied to a complex open optimization problem of technologic alternatives integrating natural and energetic resources management for underdeveloped areas in Tunisia. It identifies the main constraints, implementation opportunities and trends for the planning of a sustainable development of these regions.

Low-cost wireless sensor networks for dryland irrigation agriculture in Burkina Faso

Dryland irrigation is a major concern in arid and semiarid regions where agricultural output is low and water a scarce and vital resource. Irrigation efficiency and sustainability are, therefore, of paramount importance in these regions, where small farmers generally over-irrigate vegetables to avoid yield loss, resulting in excessive water consumption, unnecessary water pumping costs, and soil degradation. Improving dryland irrigation support requires field data, which is often scarce and unreliable in developing countries, being mostly collected manually with obsolete equipment. Modern automatic weather stations are costly, and local resources for station repair and maintenance are limited. The research project Info4Dourou2.0 aims to improve environmental data collection in developing countries by using low-cost wireless sensors networks (WSN). Hydrometeorological stations have been designed specifically for harsh environmental conditions and the limited local resources. They are simple to install and require little maintenance. The collected data is available in real time via a mobile phone and a web interface. These completely automatic stations have been developed by Ecole Polytechnique Federale de Lausanne (EPFL) and the start-up sensorscope, with the aim of being manufactured, assembled, maintained, and commercialized locally. Results of the present study show that by coupling autonomous and continuous measurements of meteorological variables with soil-water-plant-atmosphere models, we have designed a simple irrigation management system that has a strong potential to improve agricultural production: up to a 38 % yield increase has been achieved using 20 % less water compared to the unassisted way of irrigating.