The impact of the precipitation on the vegetation and ecological quality in the River of Oued Guigou, Morocco

Abstract

Understanding the impact of climate change on vegetation is essential to manage a new adaptation strategy and preserve the ecology impacted by the flow of suspended matter towards the watercourse. The main purposeof the present article is to study the relationship between the normalized difference vegetation index (NDVI) and the precipitation (P), in the Guigou basin, in the Middle Atlas of Morocco. The analysis of the relationship between NDVI and P was carried out in four phases using GIS and remote sensing tools. The NDVI was derived from Landsat TM 5 (1990), LANDSAT ETM + 7 (2000), LANDSAT TM 5 (2010), and LANDSAT OLI 8 (2020). The data on precipitation were homogenized on 2 monitoring stations of AitKabbach and Aitaissa, from 1990 to 2020, using the regional vector method and the variability. The response of vegetation to climatic parameters was represented using zonal statistics. The results show a decrease in annual precipitation during the period (1990-2020) with an increase in the year 2020. In the annual scale, linear regression reported a positive relationship between NDVI and precipitation. Thus, during the study period, the vegetation growth decreased by approximately 90%, between the years 2000 and 2010, in response to the observed climatic variation. The growth of vegetation is affected by climatic variability, in particular the precipitation. Consequently, the pedo-climatic context, favorable to erosive action and runoff, generates the transfer of eroded particles responsible for the clogging of spawning grounds, where salmonid eggs are deposited, in the Guigou wadi.