6 research outputs found
Converting oak woodland or savanna to vineyards may stress groundwater supply in summer
Water resources are important to land-use planning, especially in regions where converting native oak woodlands or savannas to wine grape vineyards may affect the amount of water available for restoring salmon runs. Research has shown that woodland conversion to grasslands (for possible rangeland grazing) leads to greater and more sustained stream flow and groundwater recharge; however, little information is available about woodland conversion to vineyards. To inform resource managers and planners, we developed a water balance model for soil and applied it to vineyards, native oak woodlands and annual grasslands to evaluate their relative use of groundwater. We applied the model to Sonoma County, using climate data from 1999 to 2011, and determined that oak tree canopy coverage of 40% to 60% results in annual groundwater extraction equivalent to that of an established irrigated vineyard. However, vineyard groundwater use far exceeded that of oak woodlands in late summer to early fall, which could further stress already affected groundwater resources. We also evaluated the prediction sensitivity of the model to key parameters associated with rain levels, soil water-holding capacity and irrigation management
Recommended from our members
Converting oak woodland or savanna to vineyards may stress groundwater supply in summer
Water resources are important to land-use planning, especially in regions where converting native oak woodlands or savannas to wine grape vineyards may affect the amount of water available for restoring salmon runs. Research has shown that woodland conversion to grasslands (for possible rangeland grazing) leads to greater and more sustained stream flow and groundwater recharge; however, little information is available about woodland conversion to vineyards. To inform resource managers and planners, we developed a water balance model for soil and applied it to vineyards, native oak woodlands and annual grasslands to evaluate their relative use of groundwater. We applied the model to Sonoma County, using climate data from 1999 to 2011, and determined that oak tree canopy coverage of 40% to 60% results in annual groundwater extraction equivalent to that of an established irrigated vineyard. However, vineyard groundwater use far exceeded that of oak woodlands in late summer to early fall, which could further stress already affected groundwater resources. We also evaluated the prediction sensitivity of the model to key parameters associated with rain levels, soil water-holding capacity and irrigation management
Converting oak woodland or savanna to vineyards may stress groundwater supply in summer
Water resources are important to land-use planning, especially in regions where converting native oak woodlands or savannas to wine grape vineyards may affect the amount of water available for restoring salmon runs. Research has shown that woodland conversion to grasslands (for possible rangeland grazing) leads to greater and more sustained stream flow and groundwater recharge; however, little information is available about woodland conversion to vineyards. To inform resource managers and planners, we developed a water balance model for soil and applied it to vineyards, native oak woodlands and annual grasslands to evaluate their relative use of groundwater. We applied the model to Sonoma County, using climate data from 1999 to 2011, and determined that oak tree canopy coverage of 40% to 60% results in annual groundwater extraction equivalent to that of an established irrigated vineyard. However, vineyard groundwater use far exceeded that of oak woodlands in late summer to early fall, which could further stress already affected groundwater resources. We also evaluated the prediction sensitivity of the model to key parameters associated with rain levels, soil water-holding capacity and irrigation management
Recommended from our members
Isotherm-based thermodynamic model for electrolyte and nonelectrolyte solutions incorporating long- and short-range electrostatic interactions.
The activities of solutes and solvents in solutions govern numerous physical phenomena in a wide range of practical applications. In prior work, we used statistical mechanics and multilayer adsorption isotherms to develop a transformative model for capturing thermodynamic properties of multicomponent aqueous solutions over the entire concentration range (Dutcher et al. J. Phys. Chem. 2011, 2012, 2013). That model needed only a few adsorption energy values to represent the solution thermodynamics of each solute. In the current work, we posit that the adsorption energies are due to dipole-dipole electrostatic forces in solute-solvent and solvent-solvent interactions. This hypothesis was tested in aqueous solutions on (a) 37 1:1 electrolytes, over a range of cation sizes, from H(+) to tetrabutylammonium, for common anions including Cl(-), Br(-), I(-), NO3(-), OH(-), ClO4(-), and (b) 20 water-soluble organic molecules including alcohols and polyols. For both electrolytes and organic solutions, the energies of adsorption can be calculated with the dipole moments of the solvent, molecular size of the solvent and solute, and the solvent-solvent and solvent-solute intermolecular bond lengths. Many of these physical properties are available in the literature, with the exception of the solute-solvent intermolecular bond lengths. For those, predictive correlations developed here enable estimation of solute and solvent solution activities for which there are little or no activity data
Recommended from our members
Isotherm-based thermodynamic model for electrolyte and nonelectrolyte solutions incorporating long- and short-range electrostatic interactions.
The activities of solutes and solvents in solutions govern numerous physical phenomena in a wide range of practical applications. In prior work, we used statistical mechanics and multilayer adsorption isotherms to develop a transformative model for capturing thermodynamic properties of multicomponent aqueous solutions over the entire concentration range (Dutcher et al. J. Phys. Chem. 2011, 2012, 2013). That model needed only a few adsorption energy values to represent the solution thermodynamics of each solute. In the current work, we posit that the adsorption energies are due to dipole-dipole electrostatic forces in solute-solvent and solvent-solvent interactions. This hypothesis was tested in aqueous solutions on (a) 37 1:1 electrolytes, over a range of cation sizes, from H(+) to tetrabutylammonium, for common anions including Cl(-), Br(-), I(-), NO3(-), OH(-), ClO4(-), and (b) 20 water-soluble organic molecules including alcohols and polyols. For both electrolytes and organic solutions, the energies of adsorption can be calculated with the dipole moments of the solvent, molecular size of the solvent and solute, and the solvent-solvent and solvent-solute intermolecular bond lengths. Many of these physical properties are available in the literature, with the exception of the solute-solvent intermolecular bond lengths. For those, predictive correlations developed here enable estimation of solute and solvent solution activities for which there are little or no activity data