Regionalization with hierarchical hydrologic similarity and ex situ data in the context of groundwater recharge estimation at ungauged watersheds

摘要: Abstract. There are various methods available for annual groundwater recharge estimation with in situ observations (i.e., obtained at the site/location of interest), but a great number watersheds around the world still remain ungauged, i.e., without hydrologic responses. One approach making estimates ungauged is regionalization, namely, transferring information gauged watersheds to ones. The reliability regionalization depends on (1) the underlying system hydrologic similarity, similarity in how respond precipitation input, as well (2) the by which is transferred. In this paper, we present nested tree-based modeling for conditioning responses on ex situ data sites/locations other than interest) while accounting uncertainties the model parameters model structure. then integrated hypothesis two-leveled hierarchical hydrologic similarity, where higher level determines relative importance of various watershed characteristics under different conditions and lower level performs estimation response of interest. We apply investigate the complicated relationship between mean recharge and watershed case study, of hierarchical explain behavior dynamic hydrologic system. Our findings reveal decisive roles soil available water content aridity regional and scales, certain which it risky to resort climate variables determining similarity. These findings contribute understanding physical principles governing robust transfer.