Hydrologic Simulation of a Winter Wheat–Summer Maize Cropping System in an Irrigation District of the Lower Yellow River Basin, China

Abstract

Conflicts between water supply and water demand are intensifying in irrigation districts along the Lower Yellow River due to climate change and human activities. To ensure both adequate food supply and water resource sustainability in China, the Soil and Water Assessment Tool (SWAT) model was used to simulate the water balance and water use of agro-ecosystems in an irrigation district of the lower Yellow River Basin, China. Simulated average annual irrigation requirements decreased from 1969 to 2010. Irrigation requirements during the winter wheat season decreased owing to reduced reference evapotranspiration and increased precipitation. Annual evapotranspiration (ET) increased with increasing irrigation volume, and differences among irrigation scenarios were mainly due to ET of winter wheat. Water deficit typically occurred during winter wheat seasons with less precipitation. Field seepage and surface runoff tended to occur in years with high precipitation, particularly during the summer maize season under full irrigation and scheduled irrigation scenarios. Frequent and heavy irrigation did not always lead to high water use efficiency. To cope with limited water resources in this region, it is necessary to properly irrigate crops based on soil water content and take full advantage of precipitation and surface runoff during the summer maize season.

Evaluating the adoption of irrigation technology in a well-irrigated winter wheat－summer maize cropping system

“…The optimization of water-saving irrigation technology was influenced by a multitude of factors, leading to the selection and innovation of irrigation evaluation criteria. There criteria were chosen and adapted with reference to both domestic and international literature, with a particular focus on the context of winter wheat-summer maize rotation [ 12 , 22 , 30 ]. The index system comprises three levels: one comprehensive-class index, five first-class indices, and 20 s-class indices ( Table 1 ).…”

Study on Mechanism and Regularity of Rock Breaking by Pulsed Water Injection with Particles

“…In order to facilitate simplification and calculation, the gravity, Basset force, Magnus force, Suffman force, and lift force of a single particle are ignored according to the characteristics and assumptions of the particle pulsed jet. Only the inertial force, drag force, pressure differential force, and additional mass force of a single particle are considered [38,39], so the one-dimensional equation of motion of a single particle is given as The Reynolds number of the particle Re s is expressed as follows:…”

Assessment of Precise Land Levelling on Surface Irrigation Development. Impacts on Maize Water Productivity and Economics

“…Hetao is located in Inner Mongolia, in the upper reaches of the Yellow River, with an irrigation area of about 676,000 ha. Water resources management in the Yellow River basin is facing a paradigmatic change in consequence of an unbalanced supply and demand, due to an increased demand for water from non-agricultural sectors and a reduced supply, due to climate change that is causing a reduced precipitation and an increased climatic demand [35][36][37]. The problem is aggravated by low equity of spatial water allocation within the basin [38].…”