Identification of the interactions and feedbacks among watershed water-energy balance dynamics, hydro-meteorological factors, and underlying surface characteristics

摘要

It is important to investigate watershed water-energy balance dynamics and their interactions and feedbacks with hydro-meteorological factors and underlying surface characteristics, to enhance the understanding of the complex interrelationships among the water, energy, soil, and biosphere cycles. In this study, the single parameter Budyko equation was used. The Budyko equation represents the water-energy balance, and the parameternrepresents all the characteristics in the system that affect the partition of precipitation (P) into runoff (R) and evapotranspiration (E). The dynamics of thenin watersheds were studied. The Granger causality was adopted to explore the interactions betweennand various influencing factors including hydro-meteorological factors and underlying surface characteristics. Two basins located in the Loess Plateau were selected as a case study. The results indicated that (1) thenof the Jing River Basin (JRB) has a continuous increasing trend and that of the Beiluo River Basin has a continuous decreasing trend; (2) there are strong interplays betweennand R, the aridity index (Ep/P), and evaporative ratio (E/P) in both watersheds; (3) soil moisture interacts with R and E/P, thereby unidirectionally influencing thenin both watersheds; and (4) the effective irrigation area interacts withnthrough its strong impacts on E/P and E-P/P in the JRB.[GRAPHICS].