Journal Article

Distribution and Growth Drivers of Oases at a Global Scale

Abd‐Elmabod, Sameh Kotb, Cui, Bochao, Gui, Dongwei, Liu, Yunfei, Lu, Binbin, Liu, Qi

2024

Overview

The human‐environmental system in drylands is centered on oases. Despite its extent and socio‐ecological importance, understanding the dynamic changes of global oases and their human and environmental driving forces is imperative for sustainable development in drylands under global warming. Nevertheless, the dynamic changes of global oases and how they respond to the evolving environment are not well established. In this study, three criteria were summarized (i.e., existing in dryland climates, surrounded or partially surrounded by desert terrain, having a reliable source of freshwater and forming landscape units with higher vegetation coverage/productivity). A global oasis distribution map from 1995 to 2020 was generated using European Space Agency Climate Change Initiative Land Cover and GIMMS‐3G+ data (overall accuracy within a 95% confidence interval is 0.85 ± 0.01) based on overlay analysis and visual interpretation. In addition, we used geographic and temporal weighted regression methods to evaluate the potential macro‐level elements affecting both global and local oasis growth. The result showed that the global oases area in 2020 occupied an area of 191.91 Mha, and most oases existed in Asia (77.3%). The global oases area has significantly increased from 1995 to 2020 (+8.65 Mha). However, about 13.43 Mha of the global oases are desertified, indicating a high risk of desertification. Water resources, contributing 51.36% to the total driver's contribution, are key to the global oasis expansion. In the context of climate (climate variability and climate change), this research highlights the need for improved holistic water resource management for long‐term global oasis growth, particularly in developing countries where the oases' development is threatened by water scarcity and desertification. Plain Language Summary In recent decades, global oases have exhibited an expanding trend. Under the backdrop of climate (climate variability and climate change), water resources profoundly influence this trend. We comprehensively assessed the distribution, dynamic changes, and factors driving the expansion of global oases. The research findings indicate that from 1995 to 2020, the global oasis area significantly increased by 8.65 Mha. However, approximately 13.43 Mha of global oases degraded into deserts, highlighting the extremely high risk of desertification. The abundance of water resources, accounting for 51.36% of the overall effect, emerges as the key determinant in global oasis growth. These findings emphasize the need for improved global comprehensive water resource management, particularly in developing countries' oasis regions, to address water scarcity and achieve the sustainable development of the oasis. Key Points Global oases changed significantly from 1995 to 2020, yet desertification risk remains severe Water resources comprise 51.36% of all drivers and are the key to the world oasis's growth In developing countries oases, climate (climate variability and climate change) will increase the demand for water resources

• Publisher: John Wiley & Sons, Inc,Wiley
• Subject: Arid lands / Arid zones / Climate change / Climate variability / Company distribution practices / Datasets / Desertification / Deserts / Developing countries / Distribution / drives / drylands / Ecosystems / Environmental aspects / global oasis / Global warming / GTWR / International aspects / International organizations / Land cover / Land use / land use land cover / LDCs / Oases / Resource management / Statistical analysis / Sustainable development / Vegetation / Water resources / Water resources management / Water scarcity / Water shortages