Response of groundwater cycle to environmental changes in Guanzhong Plain irrigation district

Healthy groundwater cycle can ensure that water resources are used more efficiently and securely in northern irrigation district. Environmental problems such as the attenuation of groundwater storage capacity, hanging pump wells and the groundwater deterioration occur with the unhealthy groundwater cycle in some northern areas, which directly affect the safety and efficiency of water resource utilization in the irrigation district. This study took Jinghui Canal Irrigation District in Shaanxi province as a research area, analyzed variations of characteristics of external environment factors for groundwater system and groundwater cycle elements over the years by trend analysis and spear-man rank correlation test. A forecasting model of groundwater depth affected by external environment was established based on multivariate time series CAR model (Controlled Auto-regressive). In order to evaluate the prediction effects of CAR model, its results were compared with those from other models including support vector m