Landscape Characterization and Dynamics of Oases in Arid Environments. A study of the Timoulay Oumaloukt and Timoulay n'Tozomte Oases in Ait Herbil (Guelmim Oued Noun - Morocco)

Abstract

The Ait Herbil oases (Timoulay Oumaloukt and Timoulay n'Tozomte) represent an ancient center of human settlement and civilization. They feature emblematic landscapes that reflect a profound interaction between humans and the natural environment. These landscapes possess both heritage and spatial identities that distinguish them from neighboring oases, due to their historical adaptation to the region’s challenging environmental conditions. A preliminary examination of the Timoulay Oumaloukt and Timoulay n'Tozomte oases reveals distinct functions and land-use patterns. These are agrarian environments shaped by a traditional subsistence economy. Over generations, farmers have molded these highly anthropized landscapes by making use of the available natural resources. However, recent environmental and socio-spatial transformations have triggered an unprecedented crisis, resulting in major imbalances within the landscape systems. The objective of this study is to characterize the anthropogenic landscapes of the Timoulay Oumaloukt and Timoulay n'Tozomte oases, located in the territorial commune of Aday, by analyzing their spatial organization, functioning, and dynamics. The methodology consists, first, of a general diagnosis and typology of the region’s anthropized landscapes. It then focuses on the current state of four specific types of anthropized features: agricultural terraces, threshing floors, collective granaries (locally known as Agadir), and agrarian landscapes. The study is primarily based on field visits and surveys, semi-structured interviews, climate data (1981–2022), and data derived from Geographic Information Systems (GIS), remote sensing, and analysis of photographic documentation collected between 2017 and 2022. NDVI imagery for 1987, 2001, and 2023 reveals a marked decline in oasis vegetation: from 61.35 ha in 1987, to 53.21 ha in 2001, and 47 ha in 2023, mainly due to recurrent droughts between 1981 and 2022. This differential dynamic reflects two contrasting trends: agricultural abandonment in some areas, and increased human pressure in others—both shaped by natural, socio-economic, and technological factors. Persistent droughts have accelerated agricultural decline, contributing to the socio-spatial exodus of the population. This research provides a scientific foundation for further investigation into oasis landscapes, offering critical insights to inform regional strategies for resource management and heritage conservation.