Evaluating performance of soil water movement and groundwater recharge in an irrigated agricultural area of Yinchuan Plain, China

Abstract

Surface irrigation has been predominantly used for field crops in agriculture area to boost agricultural yields and outputs, however, this may also raise groundwater tables, salinize soils and reduce water quality due to poor irrigation management. Therefore, it is essential for requiring a better understanding of the hydrologic mechanisms related to soil water fluxes (e.g., evaporation, transpiration, infiltration, deep percolation and groundwater capillary rise) by surface irrigation. This study investigated the impact of surface irrigation on soil water movement and recharge to groundwater in the Yellow River irrigation area of Yinchuan Plain, China. Combining comprehensive filed observation and stable isotopic techniques, we described the soil water mechanism under two land covers (bare ground or maize) in 2019 and 2020. The soil depths affected by precipitation infiltration and evaporation were mainly 0-50 cm, while the soil influenced by irrigation was the entire profile in the mode of piston flow. According to soil water potential variation from 70 to 100 cm, we conclude that the maize root took up the soil water up to the depth of 100 cm during the tasseling period. The infiltration and capillary rise in 2020 were similar with those in 2019. However, the total deep percolation was 156.6 mm in 2020 which was smaller than that in 2019 because of the maize root water uptake. The leakage of ditch was the major recharge resource of groundwater for the fast water table rise. This study is critical for agricultural water management to improve irrigation efficiency and water use efficiency in arid regions.

Coupled DSSAT and HYDRUS-1D Simulation of the Farmland–Crop Water Cycling Process in the Dengkouyangshui Irrigation District

“…After years of development, HYDRUS-1D has seen widespread use and can effectively model variations in soil moisture, temperature, and solute concentrations due to agricultural irrigation and fertilization. The vertical transport of soil moisture in both saturated and unsaturated media is governed by the modified Richards equation and the van Genuchten model [27], as detailed in Equations ( 5)- (8):…”

“…The water cycle serves as the crucial link connecting various terrestrial systems, such as the hydrosphere, atmosphere, lithosphere, and biosphere [2] Hydrological models [3][4][5][6] have proven to be effective tools for exploring the complex mechanisms of water cycling in irrigation districts and are indispensable in research related to water resource management and the impact of human productive activities on the water cycle [7]. Numerous scholars have carried out both experimental and numerical simulation studies on the water cycle in irrigation areas [8][9][10]; however, these investigations tend to be expensive and time-consuming, and the outcomes are often specific to each study. The advent of the hydraulic model HEC-RAS [11] and agricultural hydrological models such as HYDRUS [12], SWAT [13], and SWAP [14] has provided deeper insights into the dynamics of soil moisture and the behavior of water cycles within irrigation districts [15].…”

The Mechanism of the Influence of Different Irrigation Methods on Groundwater Recharge

“…They found that groundwater was recharged by rainfall, the Yellow River, and irrigation. Yin [20] used the resistivity sounding method to explore the groundwater recharge conditions at a depth of 300 m in the Yinchuan Plain based on hydrogeological survey results from previous studies. The results showed that the source of groundwater recharge of the proluvial fan in the Helan Mountains is atmospheric precipitation and bedrock fissure water.…”