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Ecohydrology of groundwater‐dependent ecosystems: 2. Stochastic soil moisture dynamics
Author(s) -
Tamea Stefania,
Laio Francesco,
Ridolfi Luca,
D'Odorico Paolo,
RodriguezIturbe Ignacio
Publication year - 2009
Publication title -
water resources research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.863
H-Index - 217
eISSN - 1944-7973
pISSN - 0043-1397
DOI - 10.1029/2008wr007293
Subject(s) - ecohydrology , environmental science , water content , water table , soil science , groundwater , hydrology (agriculture) , infiltration (hvac) , soil water , hydrogeology , vegetation (pathology) , ecosystem , geology , ecology , geography , geotechnical engineering , medicine , pathology , meteorology , biology
In groundwater‐dependent ecosystems, interactions between rainfall, water table fluctuations, and vegetation are exerted through the soil water content. The dynamics of soil moisture, in fact, are strongly coupled to fluctuations of the water table and, together, they control the overall ecosystem dynamics. We propose here a simple process‐based stochastic model for the study of soil moisture dynamics at a generic depth, to complement the stochastic model of water table depth presented in the companion paper. The model presented here is based on a local and depth‐dependent water balance driven by stochastic rainfall (marked Poisson noise) and accounting for processes such as rainfall infiltration, root water uptake, and capillary rise. We obtain a semianalytical formulation of the stationary probability distribution of soil water content at different depths, which is studied for different values of soil, climate, and vegetation parameters. The probability distributions are used to investigate the ecohydrology of groundwater‐dependent ecosystems, including the quantitative description of the vegetation–water table–soil moisture interplay and the probabilistic analysis of root water uptake.