Urban detection using Decision Tree classifier: a case study

This work constitutes a first step towards the definition of a methodology for automatic urban extraction from medium spatial resolution Landsat data. Decision Tree is investigated as classification technique due to its ability in establishing which is the most relevant information to be used for the classification process and its capability of extracting rules that can be further ap-plied to other inputs. The attention was focused on the evaluation of parameters that better define the training set to be used for the learning phase of the classifier since its definition affects all the next steps of the process. Different training sets were created by combining different features, such as different level of radiometric pre-processing applied to the input images, the number of classes considered to train the classifier, the temporal extent of the training set and the use of different at-tributes (bands or spectral indexes). Different post-processing techniques were also evaluated. Classifiers, obtained by the generated training sets, were evaluated in two different areas of Pied-mont Region, where the official regional cartography at scale 1:10000 was used for validation. Accuracies round 81% in the Torino case study and around 96%-97% in Asti case study were reached, thanks to the use of indexes such as NDVI and NDBBBI and the use of post-processing such as majority filtering that allowed enhancing classifier performances

Base cartography for land and water management in Sahel

Base cartography at proper scale for land and water management is rarely present in Least Developed Countries (LDCs). Despite the massive presence of international cooperation programs and projects carried out in various LDCs, a low budget is usually allocated for base data retrieval helpful for a wide range of on-site actions. A food security project in Burkina Faso, aiming at increasing the agricultural production through supporting farmers’ unions, is herein used as a case study. In this framework update cartography at large scale was needed in order to plan Soil and Water Conservation (SWC) interventions at catchment scale. However, best existing official maps dated 1984 and were at 1.50.000 scale, a highly coarse detail level to intervene at the defined scale. Data at higher resolution were available at the national cartographic institute, obtained from aerial surveys performed in the last decade. Remote sensed data allowed to perform feature extraction over the areas of interest, thus updating the existing cartography and making it suitable for the foreseen activities such as hydrological modeling and land and water management planning

An approach to monitoring drought events and food security conditions

Early Warning Systems (EWS) for drought are currently underdeveloped compared to other hazards. In fact, the multifaceted nature of drought (i.e. hydrological, meteorological, and agricultural) necessitates a number of different ways to measure this phenomenon and its effects. In the present study an approach to identifying and monitoring drought events is presented. The EWS developed is based on the early detection and monitoring of vegetation stress on a global scale. Moreover, a simplified vulnerability model, applied to the hazard data, yields the food security conditions for the investigated area. The model includes agricultural indicators and socio-economic factors linked to people’s strategy to supply the food they need. The performance of the proposed EWS is reported for a case study which confirms its potential usefulness for decision-makers and humanitarian actors operating in the context of drought and famine crisis

Cost-effectiveness of soil and water conservation measures on the catchment sediment budget - the Laaba watershed case study, Burkina Faso

In the Sahelian region, the high precipitation intensity and the daily rainfall extreme values are currently the main cause of soil erosion and land degradation. In addition, solid transport often leads to reservoir siltation and reduction of the amount of water available for agriculture. To cope with these issues, Soil and Water Conservation (SWC) measures have been regularly employed in the Sahelian area. However, a proper cost-effectiveness analysis of the impact of SWC interventions on the catchment sediment budget normally requires quantitative surveys on erosion and sedimentation processes. Where data for calibration and validation of models are scarce, an overall methodology to evaluate the economical sustainability of a proposed intervention can be of paramount importance. The study herein proposed aims to assess the monetary sustainability of SWC measures in limiting the reservoir siltation of the Laaba dam (Yatenga District, Northern Burkina Faso). In particular, the catchment sediment budget was estimated by means of morphological and pedologic parameters and dam sedimentation rates; a cost-effectiveness analysis was then performed to assess the economic sustainability of a possible SWC intervention. The proposed methodology showed interesting potentials for land and water management in Burkina Faso, particularly when data and financial resources are limited and where the application of detailed process-based models is not possible

An approach to monitoring drought events and food security conditions

Early Warning Systems (EWS) for drought are currently underdeveloped compared to other hazards. In fact, the multifaceted nature of drought (i.e. hydrological, meteorological, and agricultural) necessitates a number of different ways to measure this phenomenon and its effects. In the present study an approach to identifying and monitoring drought events is presented. The EWS developed is based on the early detection and monitoring of vegetation stress on a global scale. Moreover, a simplified vulnerability model, applied to the hazard data, yields the food security conditions for the investigated area. The model includes agricultural indicators and socio-economic factors linked to people’s strategy to supply the food they need. The performance of the proposed EWS is reported for a case study which confirms its potential usefulness for decision-makers and humanitarian actors operating in the context of drought and famine crisis