Irrigated agriculture greatly affects the hydrological systems and thereby eco-environment and food security in arid and semi-arid regions. However, a comprehensive assessment of the hydrological system dynamics in response to irrigated agriculture is still scarce, especially in oasis-desert systems of arid inland regions. Thus, we investigated the impact of irrigated agriculture on hydrological regimes in an oasis-desert system of northwest China. Temporal variations in water balance and lateral groundwater flow in oasis and desert experimental fields (i.e. oasis plot and desert plot) were quantified using the water balance analysis method. Soil water variations, groundwater dynamics and surface water and groundwater interactions in the oasis-desert system were determined by combining line transect survey methods and stable isotope (¹⁸O, ²H) techniques using the USGS MODFLOW software. The results showed that water exchange fluxes and groundwater dynamics were altered by the application of water-saving irrigation techniques and the increase in total precipitation. In particular, the downward total exchanging flux above groundwater table and the outward total lateral groundwater flow reduced significantly in the oasis plot. Spatial heterogeneity and profile variability of soil moisture along the soil water content (SWC) transect significantly reduced. Simultaneously, the depth dependence of SWC in oasis cropland and the deep soil moisture at the edge of desert were improved under water-saving irrigation scenario. Temporal variations in groundwater table depths (GTDs) exhibited three different patterns (i.e. stable, metastable and fluctuating) and maintained a continuously downward trend except for the oasis-desert ecotone along the GTD transect, and an abrupt change was found to have occurred during 2006–2012, prompting changes in the seasonality of groundwater resource availability. Groundwater recharge and discharge processes changed dramatically due to large-scale land reclamation and groundwater pumping. Groundwater depletion is approaching hydrological limits although the process is largely compensated by precipitation and streamflow variability. Water-saving irrigation in conjunction with restriction of land reclamation and adaptation of water management practices is, at least for the present, the most effective way to maintain the coexistence of oasis and desert ecosystems in arid inland regions.

灌溉农业极大地影响了水文系统，从而影响了干旱和半干旱地区的生态环境和粮食安全。但是，仍然缺乏对灌溉农业响应的水文系统动力学的综合评估，特别是在干旱内陆地区的绿洲-沙漠系统中。因此，我们调查了西北西北绿洲荒漠系统中灌溉农业对水文状况的影响。使用水平衡分析方法对绿洲和沙漠试验场（即绿洲地块和沙漠地块）中水平衡和地下水侧向流动的时间变化进行了定量。结合线样线调查方法和稳定同位素，确定了绿洲-荒漠系统中的土壤水分变化，地下水动力学以及地表水与地下水的相互作用（¹⁸ O，²H）使用USGS MODFLOW软件的技术。结果表明，节水灌溉技术的应用和总降水量的增加改变了水交换通量和地下水动力学。特别是，在绿洲区，地下水位以上的向下总交换通量和地下水总侧向流量显着减少。沿土壤含水量（SWC）断面的土壤水分空间异质性和剖面变异性显着降低。同时，在节水灌溉的情况下，绿洲农田SWC的深度依赖性和沙漠边缘深层土壤水分得到改善。地下水位深度（GTD）的时间变化表现出三种不同的模式（即稳定，除了沿GTD断面的绿洲-荒漠过渡带外，并保持了持续下降的趋势，并发现2006-2012年间发生了突然变化，促使地下水资源可利用性的季节性变化。由于大规模土地开垦和抽水，地下水的充排过程发生了巨大变化。尽管这一过程在很大程度上受到降水和水流变化的影响，但地下水的消耗正接近水文极限。至少就目前而言，节水灌溉与限制土地开垦以及适应水管理实践是保持干旱内陆地区绿洲和沙漠生态系统共存的最有效方法。