Simulating drip irrigation in large-scale and high-resolution ecohydrological models: From emitters to the basin

Han, Feng1,2; Zheng, Yi1,2,5; Zhang, Ling3,6; Xiong, Rui1; Hu, Zhaoping1; Tian, Yong1,2; Li, Xin4

2023-11-01

10.1016/j.agwat.2023.108500

AGRICULTURAL WATER MANAGEMENT   Impact Factor & Quartile

0378-3774

1873-2283

Drip irrigation is deemed as a solution to the water conflict between agricultural and ecological needs in arid regions, but assessing hydrological impacts of drip irrigation remains challenging. This study developed a new approach to simulating drip irrigation at a basin scale, with the configuration of irrigation system explicitly represented and the emitter-scale wetted soil volume directly modeled, and incorporated the approach into HEIFLOW, a fully distributed and physically based ecohydrological model. The improved model, named HEIFLOW-drip, was used to study the potential implementation of drip irrigation in the Zhangye basin in Northwest China. Due to the recycling effect of irrigation return flow, the basin-scale water-saving efficiency (WSE) of drip irrigation fully implemented in the irrigated farmlands is 16.8%, less than half of its field-scale WSE (36.5%). This discrepancy indicates that accounting the water saved in fields may lead to notable over-estimation of the basin-wide water saving by drip irrigation in basins with strong surface water-groundwater interactions. If fully implemented, drip irrigation would significantly alter the regional water balance, increasing the stream outflow by approximately 30%, while causing a decline in groundwater level. This tradeoff can be alleviated by tuning the management parameters of drip irrigation, which can achieve a synergistic effect of increasing the streamflow while preventing dramatic groundwater depletion. Another effective strategy is to implement drip irrigation in part of the basin. Given the intricate impacts of drip irrigation on hydrological processes, the determination of the scale and location of drip irrigation should be thought through at the basin level. Further analyses indicate the importance of proper management of the water saved by drip irrigation, which is crucial to prevent the paradox of irrigation efficiency. The findings of this study have great implications for addressing the complex water-food-ecosystem nexus in arid endorheic river basins.

Drip irrigation Endorheic river Arid region Ecohydrological modeling Groundwater HEIFLOW

SCI

English

First ; Corresponding

Strategic Priority Research Program of the Chinese Academy of Sciences[XDA20100104] ; National Natural Science Foundation of China["41901045","41807164"]

Agriculture ; Water Resources

Agronomy ; Water Resources

WOS:001075063100001

ELSEVIER

AGRICULTURAL SCIENCES

Web of Science

1.Southern Univ Sci & Technol, Sch Environm Sci & Engn, Shenzhen 518055, Peoples R China
2.Southern Univ Sci & Technol, Shenzhen Municipal Engn Lab Environm IoT Technol, Shenzhen 518055, Peoples R China
3.Chinese Acad Sci, Northwest Inst Ecoenvironm & Resources, Lanzhou 730000, Peoples R China
4.Chinese Acad Sci, Inst Tibetan Plateau Res, Beijing 100101, Peoples R China
5.Southern Univ Sci & Technol, 1088 Xueyuan Ave, Shenzhen 518055, Guangdong, Peoples R China
6.Northwest Inst Ecoenvironm & Resources, 320 Donggang West Rd, Lanzhou 730000, Gansu, Peoples R China

Han, Feng,Zheng, Yi,Zhang, Ling,et al. Simulating drip irrigation in large-scale and high-resolution ecohydrological models: From emitters to the basin[J]. AGRICULTURAL WATER MANAGEMENT,2023,289.

Han, Feng.,Zheng, Yi.,Zhang, Ling.,Xiong, Rui.,Hu, Zhaoping.,...&Li, Xin.(2023).Simulating drip irrigation in large-scale and high-resolution ecohydrological models: From emitters to the basin.AGRICULTURAL WATER MANAGEMENT,289.

Han, Feng,et al."Simulating drip irrigation in large-scale and high-resolution ecohydrological models: From emitters to the basin".AGRICULTURAL WATER MANAGEMENT 289(2023).