The communication will focus on the factors behind the dynamics of spatial expansion of an oasis based on the case of Al-Ula, located in northwestern Saudi Arabia. Despite a few narratives of old travelers (in particular, Jaussen and Savignac, 1914) and the doctoral thesis of A. Nasif (Nasif, 1988), the textual and cartographic sources allowing us to apprehend the spatial structure of this oasis are extremely scarce. However, the systematic pedestrian archaeological surveys carried out since the end of 2019 within the framework of the Al-Ula Cultural Oasis Project (UCOP) – led by Archaïos, funded and steered by the French Agency for AlUla Development (AFALULA), on behalf of the Royal Commission for AlUla (RCU) – coupled with the analysis of old and recently acquired satellite imageries, enable us to identify, for the first time, the successive states of the oasis’ spatial organization since the end of the 19th century AD. One of the major spatial change during this period is the expansion of the oasis in successive phases, more or less rapid in time and substantial in space. Two concomitant approaches are proposed to understand the conditions of emergence of the identified spatial structures: 1) their schematic representation, in the tradition of the graphic models of chrono-chorematic (Rodier, Grataloup and Guilloteau, 2010), but with particular attention paid to the schematization of change (Nahassia, 2019); 2) the construction of spatial accessibility models based on the structure of the occupation. Through this thematic case, the objective of the communication is to discuss the multiplicity of factors leading to the same process – in this instance, the spatial expansion of an oasis and its palm grove – and to debate some of the means that can be implemented to think about spatial dynamics in the long term.