Application of Budyko framework to irrigation districts in China under various climatic conditions

Abstract

Budyko's framework has been widely used to study basin‐scale water balance. In this study, we focus on the extended application of Fu's equation (one formulation of the Budyko‐type curves) to 371 large irrigation districts in China over a period of 2010–2017. Water balance method was used to estimate actual evapotranspiration )(ET in the irrigated areas. Considering the contribution of shallow groundwater to ET, the water availability in the Budyko framework defined as equivalent precipitation )(Pnormale for irrigation areas is the sum of irrigation water )(I, precipitation )(P and groundwater evaporation )(ETgw. Results showed that the relationships between evapotranspiration )(ET, water availability )(Pnormale and energy supply )(ET0 can be accurately described by the Budyko's curves. The optimal values of Budyko parameter ω for each irrigation district was obtained with multi‐annual data using least square method. The Fu's equation performed better in humid and semi‐humid regions than arid and semi‐arid regions. The comparison between ∂ET/∂Pe and ∂ET/∂ET0 confirmed the relative effect of water availability and energy supply on ET according to the variation of climatic conditions. Normalized difference vegetation index (NDVI) and soil properties (denoted by the proportion of clay and sand) were selected to develop empirical equation for parameter ω using multiple linear regression analysis method. This study shows that the Budyko framework can be extended to irrigation areas and provides useful information on evapotranspiration to assist in water management in irrigation areas.

Controlling Factors of Evapotranspiration Predictability Under Diverse Climates With the Effects of Water Storage Change in the Budyko Framework

“…For example, when annual Δ S is negative (Equation ), but a large R is likely caused by human activities (e.g., water transfer project). Another example is (as in Equation ) that although R is decreasingly low during dry season, irrigation in agricultural areas may increase the water availability (Chen et al., 2022), which may also lead to the out‐of‐phase relationship between Δ S and R . In summary, the proposed QFEP framework in this study has the potential to predict and explain the impact of human activities in estimated ET from the extended BM incorporating Δ S .…”

“…The BM can be considered as a lumped, first‐order estimation of long‐term P partitioning into ET and R by utilizing the physical, empirical, and statistical models (Budyko, 1958, 1974; Fu, 1981; Gerrits et al., 2009; Mezentsev, 1955; Porporato et al., 2004; Yang et al., 2008; Zhang et al., 2004). This method has been widely used to investigate the relations between the long‐term mean climatology and hydrologic balance as a function of climate factors and catchment characteristics (e.g., Chen et al., 2022; Donohue et al., 2010, 2011; Roderick & Farquhar, 2011; Wang & Hejazi, 2011; Wu et al., 2017; Yang et al., 2009; Zhang et al., 2016a).…”

“…10.1029/2023WR034499 2 of 19 Porporato et al, 2004;Yang et al, 2008;Zhang et al, 2004). This method has been widely used to investigate the relations between the long-term mean climatology and hydrologic balance as a function of climate factors and catchment characteristics (e.g., Chen et al, 2022;Donohue et al, 2010Donohue et al, , 2011Roderick & Farquhar, 2011;Wang & Hejazi, 2011;Wu et al, 2017;Yang et al, 2009;Zhang et al, 2016a).…”