Assessing Impact of Agroecological Interventions in Niger through Remotely-Sensed Changes in Vegetation

Abstract:

To promote long-term food security and resilience for areas with vulnerable populations, the World Food Program (WFP) has implemented various intervention methods at specific locations in southern Niger as part of the US Agency for International Development (USAID)’s Food for Peace (FFP) program. This effort focuses specifically on the intervention sites where soil and water retention structures in the shape of semi-circles, known as pastoral half-moons, were built in order to sustain agriculture in low-rainfall areas. The effectiveness of these pastoral half-moons as an agroecological intervention method will be assessed through examination of changes in vegetation health over time.

Firstly, intervention sites were digitized using high-resolution satellite imagery in Google Earth Pro. We then used Google Earth Engine (GEE) to construct a time-series of Normalized Difference Vegetation Index (NDVI) and precipitation for each FFP intervention site location in order to measure the extent of change brought about by FFA intervention. Landsat data is used to characterize the NDVI time series to monitor the vegetation change over time, whereas CHIRPS rainfall data provided the ability to quantify the changes in vegetation due to the rainfall at the location.

Based on our initial analysis, it appears that the half-moon interventions have improved vegetation health at several FFP sites. In order to improve our current analysis it is necessary to have our digitized intervention sites verified in person as well as address the gaps in our NDVI data. Accurate information about site boundaries and more comprehensive NDVI measurements will aid in determining the extent of improvement that half-moon interventions are able to provide. This presentation will illustrate our latest results and the next steps.