A semi-distributed drainage model for monthly drainage water and salinity simulation in a large irrigation district in arid region

Yeqiang Wen, Songhao Shang, Khalil Ur Rahman, Yuhong Xia and Dongyang Ren

Agricultural Water Management, 2020, vol. 230, issue C

Abstract: The complex and dense irrigation and drainage networks and diverse irrigation scheduling result in uncertainties and complexities in the simulation of drainage water and salinity at different regional scales. We propose a semi-distributed model to simulate monthly drainage water and salinity, considering both the surface return flow and groundwater drainage to drainage ditches. The model uses sub-drainage command areas (SDCAs) controlled by main irrigation canals and drainage ditches as simulation units and uses a conceptual model to estimate monthly drainage water and salinity from each SDCA. The proposed model is applied in the Hetao Irrigation District (HID) in North China with 19 SDCAs, and calibrated and validated using monitoring data during 2008–2010 and 2012–2013, respectively. The results reveal better model performance in estimating the drainage water and salinity at SDCA, sub-irrigation district and irrigation district scales. The average annual drainage is 47,021 * 104m3 in HID, accounting for 10.5 % of the annual irrigation water amount. The surface return flow and groundwater drainage account for 32.7 % and 67.3 % of total drainage, respectively. The ratio of surface return flow to groundwater drainage is higher in the upstream area and lower in the downstream area. Higher surface return flow ratio (>5 %) is observed in the western Wulanbuhe, middle and southern Jiefangzha, and northern Wulate sub-irrigation areas, indicating the necessity to improve irrigation water management in these areas. Lower groundwater drainage capability is observed in western and southern HID, while enhanced groundwater drainage capability is observed in northern HID. Average annual salt leaching through the drainage system is 126.5 * 104 t, which is only 43 % of the total salt introduced from irrigation. The Wulate sub-irrigation district performs best on salt leaching, while other sub-irrigation district should improve the drainage system and irrigation water use efficiency to control the salt accumulation.

Keywords: Drainage; Semi-distributed model; Surface return flow; Groundwater drainage; Irrigation district (search for similar items in EconPapers)
Date: 2020
References: View references in EconPapers View complete reference list from CitEc
Citations: View citations in EconPapers (8)

Downloads: (external link)
http://www.sciencedirect.com/science/article/pii/S0378377419307693
Full text for ScienceDirect subscribers only

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:eee:agiwat:v:230:y:2020:i:c:s0378377419307693

DOI: 10.1016/j.agwat.2019.105962

Access Statistics for this article

Agricultural Water Management is currently edited by B.E. Clothier, W. Dierickx, J. Oster and D. Wichelns

More articles in Agricultural Water Management from Elsevier
Bibliographic data for series maintained by Catherine Liu ().