Improving ecological water diversion process to promote oasis restoration using a monthly conceptual lumped ecohydrological model: A case study of the Qingtu Oasis, China

Qingtu Oasis, Shiyang River Basin, Northwest China. Improving the Ecological Water Diversion (EWD) process is crucial for promoting recovering terminal oases in arid inland basins. This research developed a Monthly Conceptual Lumped Ecohydrological Model (MCLEM) by integrating the surface water and groundwater balance, ecological response, and evapotranspiration equations. The MCLEM coupling with the scenario simulation effectively depicted the oasis’s intra-annual ecohydrological dynamics responding to various EWD processes under wet, regular, and dry meteorological conditions, implying for designing a rational EWD strategy achieving optimal ecological benefits regarding a larger oasis area and higher vegetation coverage. Given the total volume of 30 million m 3, the current EWD of 10 million m 3 each month during the second half of the vegetation growing season recovered the Qingtu Oasis to an average peak oasis area of 16.90 km 2 and an average peak vegetation coverage of 15.90 % under various meteorological conditions. Comparatively, the EWD of 5 million m 3 each month during the entire vegetation growing season could produce an average peak oasis area of 20.17 km 2 and an average peak vegetation coverage of 18.59 %. Comparing the ecological benefits resulting from different EWD scenarios suggested adjusting the EWD process from transferring water during the second half of the vegetation growing season to transferring water during the entire vegetation growing season.