An entropy‐based measure of hydrologic complexity and its applications. Issue 7 (14th July 2015)

• Record Type: Journal Article
• Authors: Castillo, Aldrich; Castelli, Fabio; Entekhabi, Dara
• Is Part Of: Water resources research. Volume 51:Issue 7(2015:Jul.)
• Page Start: 5145
• Page End: 5160
• Publication Date: 2015-07-14
• Subjects: distributed hydrology -- hydrologic response -- hydrologic complexity -- soil moisture -- information entropy; Hydrology -- Periodicals; 333.91
• DOI: 10.1002/2014WR016035
• Languages: English
• ISSNs: 0043-1397

Abstract

Abstract: Basin response and hydrologic fluxes are functions of hydrologic states, most notably of soil moisture. However, characterization of hillslope‐scale soil moisture is challenging since it is both spatially heterogeneous and dynamic. This paper introduces an entropy‐based and discretization‐invariant dimensionless index of hydrologic complexity H that measures the distance of a given distribution of soil moisture from a Dirac delta (most organization) and a uniform distribution (widest distribution). Applying the distributed hydrologic model MOBIDIC to seven test basins with areas ranging 10 0 −10 3 km 2 and representing semiarid and temperate climates, H is shown to capture distributional characteristics of soil moisture fields. It can also track the temporal evolution of the distributional features. Furthermore, this paper explores how basin attributes affect the characteristic H, and how H can be used to explain interbasin variability in hydrologic response. Relationships are found only by grouping basins with the same climate or size. For the semiarid basins, H scales with catchment area, topographic wetness, infiltration ratio, and base flow index; while H is inversely related to relief ratio. Key Points: Basin hydrologic response is a function of soil moisture distributional features An information‐based dimensionless index of hydrologic complexity is applied The complexity index characterizes soil moisture distributional features