JoVE - Journal of Visualized Experiments
JoVE Visualize
Contact Us

Soil water dynamics and deep percolation in an agricultural experimental area of the North China Plain over the past 50 years: Based on field monitoring and numerical modeling

  • 0College of Geosciences and Engineering, North China University of Water Resource and Electric Power, Zhengzhou 450045, China; The Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Science, Shijiazhuang 050061, China.
The Science of the Total Environment +

|

April 13, 2024

|

April 13, 2024

View abstract on PubMed

Summary

This summary is machine-generated.

Unregulated irrigation caused severe deep percolation (DP) in North China. While DP decreased over 50 years, significant water loss persists, necessitating improved irrigation for water-use efficiency.

Area Of Science

  • Agricultural Hydrology
  • Environmental Science
  • Soil Science

Background

  • Unregulated irrigation in the late 20th century severely impacted North China Plain's agricultural areas, leading to significant deep percolation (DP).
  • This deep percolation poses a major challenge to efficient water resource utilization and sustainable development in these critical agricultural regions.
  • The complex hydrodynamics of thick vadose zones, influenced by climate change and human activities, make accurate quantification of DP difficult.

Purpose Of The Study

  • To investigate and quantify deep percolation (DP) in the Luancheng Agricultural Irrigation District over a 50-year period (1971-2021).
  • To analyze the soil-water dynamics and hydrodynamic properties of the thick vadose zone under varying irrigation and precipitation conditions.
  • To assess the impact of evolving irrigation measures on DP and identify key factors influencing water loss.

Main Methods

  • Conducted a continuous 20-year in situ experiment in the Luancheng Agricultural Irrigation District.
  • Monitored soil-water dynamics using neutron probes and tensiometers to capture the annual soil-water cycle.
  • Simulated deep percolation (DP) using the HYDRUS-1D model, validated against observed data from 1971-2021.

Main Results

  • Soil water content (SWC) trends were consistent across varying irrigation and precipitation levels; recharge exceeding 60 mm/d triggered percolation.
  • Deep percolation predominantly occurred post-irrigation or during intensive precipitation (July-October), with a maximum rate of 16.9 mm/d.
  • Soil water storage capacity (R² = 0.86) and precipitation (R² = 0.54) were the primary drivers of deep percolation.

Conclusions

  • Average deep percolation (DP) decreased from 574.2 mm (1971-1990) to 435.5 mm (2005-2021) due to improved irrigation measures.
  • Despite reductions, substantial amounts of irrigation and precipitation still infiltrate deeply, remaining unutilized by crops.
  • Urgent implementation of measures to reduce deep percolation is crucial for enhancing agricultural water-use efficiency in the region.

Keywords: