EFFECTS OF LAND USE CHANGE ON THE RIPARIAN ZONES' QUALITY ALONG THE ZAT RIVER AND ITS TRIBUTARIES: HIGH ATLAS OF MOROCCO

This study was conducted to assess the quality of riparian zones of Zat basin of Morocco by using the QBR index, and to analyze land use changes over 30 years along the Zat River and its tributaries by using remote sensing and Geographic Information System. Five land use/land cover classes were identified: Forest, building area, water, bare soil, and agricultural land using Landsat images. Also, the QBR index was evaluated in 14 localities distributed along the Zat River and its tributaries from 2018-2019. For instance, the total forest area was reduced from 959.07 ha (15.35%) in 1990 to 890.41 ha (14.25%) and 713.25 ha (11.41%) in 2005 and 2020, respectively. Whereas agricultural land and building area classes increased with an estimated rate of change of 24.99% and 33.81% respectively over the last 30 years. Furthermore, our results indicate that 35.7% of the banks in the riparian zone are of very poor quality, 14.3% of poor quality, 28.6% of average quality and 21.4% of good quality. The finding demonstrates that the low QBR score obtained by some sampling localities especially downstream is the result of multiple anthropogenic interventions in riparian ecosystems, including forest plantations, land use for agriculture, and road infrastructures.