Simulating oasis-desert interactions in artificial and natural oasis-desert areas: Integration of remote sensing data and CFD methodology

Abstract

The rapid expansion of oasis areas and seasonal water scarcity pose significant threats to the stability and maintenance of oases. Oases and deserts exhibit distinct dynamic and hydrothermal properties, resulting in oasis-desert interactions that help alleviate the situation. However, due to difficulties in adequately characterizing the high dynamic and thermal heterogeneities of the real oasis-desert underlying surface at a fine scale, previous studies usually focus on the simulation of ideal scenarios and coarse resolution, which limits further studies of oasis-desert interactions on real oasis-desert underlying surface. In this study, the high spatiotemporal resolution remotely sensed data, including leaf area density (LAD) and land surface temperature (LST), have been acquired to characterize the dynamic and thermal heterogeneities of the oasis-desert underlying surface at a fine scale, which then have been integrated into the improved computational fluid dynamics (CFD) model to simulate the wind speed (U), air temperature (T), and specific humidity (q) with high spatiotemporal resolution (30 m/1 hour) over artificial and natural oasis-desert areas located in the Heihe River Basin. The CFD simulations (U, T, and q) agree well with the observations, with mean bias errors of 0.3 (-0.1) m/s, 1.4 (1.2) °C, and -0.4 (0.1) g/kg, respectively, in the artificial (natural) oasis area. The background wind conditions and the hydrothermal difference between the oasis and desert strongly affect the oasis-desert interactions. Local circulation manifests in the artificial oasis under calm wind conditions, but it is absent in the natural oasis. The artificial oasis exhibit more pronounced micrometeorological effects than natural oasis. This study advances the understanding of oasis-desert interactions and the distinctions between artificial and natural oases, thereby providing valuable insights for promoting the stability and sustainable development of oases in the arid regions of Northwest China and along the Silk Road.