Open AccessImprovement of the Irrigation Scheme in the ORCHIDEE Land Surface Model and Impacts of Irrigation on Regional Water Budgets Over China
Author(s) -
Yin Z.,
Wang X. H.,
Ottlé C.,
Zhou F.,
Guimberteau M.,
Polcher J.,
Peng S. S.,
Piao S. L.,
Li L.,
Bo Y.,
Chen X. L.,
Zhou X. D.,
Kim H.,
Ciais P.
Publication year - 2020
Publication title -
journal of advances in modeling earth systems
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.03
H-Index - 58
ISSN - 1942-2466
DOI - 10.1029/2019ms001770
Subject(s) - irrigation , environmental science , water resources , irrigation statistics , surface irrigation , water resource management , hydrology (agriculture) , surface water , irrigation management , irrigation district , deficit irrigation , environmental engineering , agronomy , geology , ecology , geotechnical engineering , biology
In China, irrigation is widespread in 40.7% cropland to sustain crop yields. By its action on water cycle, irrigation affects water resources and local climate. In this study, a new irrigation module, including flood and paddy irrigation technologies, was developed in the ORCHIDEE‐CROP land surface model which describes crop phenology and growth in order to estimate irrigation demands over China from 1982 to 2014. Three simulations were performed including NI (no irrigation), IR (with irrigation limited by local water resources), and FI (with irrigation demand fulfilled). Observations and census data were used to validate the simulations. Results showed that the estimated irrigation water withdrawal ( W ) based on IR and FI scenarios bracket statistical W with fair spatial agreements ( r = 0 . 68 ± 0 . 07 ; p < 0 . 01 ). Improving irrigation efficiency was found to be the dominant factor leading to the observed W decrease. By comparing simulated total water storage (TWS) with GRACE observations, we found that simulated TWS with irrigation well explained the TWS variation over China. However, our simulation overestimated the seasonality of TWS in the Yangtze River Basin due to ignoring regulation of artificial reservoirs. The observed TWS decrease in the Yellow River Basin caused by groundwater depletion was not totally captured in our simulation, but it can be inferred by combining simulated TWS with census data. Moreover, we demonstrated that land use change tended to drive W locally but had little effect on total W over China due to water resources limitation.