in this paper, optimal distributed control of the time-dependent navier-stokes equations is considered. the control problem involves the minimization of a measure of the distance between the velocity field and a given target velocity field. a mixed numerical method involving a quasi-newton algorithm, a novel calculation of the gradients and an inhomogeneous navier-stokes solver, to find the opt...

This paper focuses on the quantification of the green – vegetation related – water flux of forest stands in the temperate lowland of Flanders. The underlying reason of the research was to develop a methodology for assessing the impact of forests on the hydrologic cycle in comparison to agriculture. The tested approach for calculating the water use by forests was based on the application of the ...

Full coupling of physical processes, natural numerical coupling, and parsimonious but accurate data coupling are three key steps in efficient and accurate simulation of distributed hydrologic states in watersheds. Here we present a physically-based, spatially distributed hydrologic model (called PIHM) that utilizes all the three coupling strategies. Interception, snow melt, transpiration, evapo...

abstract to optimal use of available water, irrigation scheduling is important to over scarcity of water resources in arid and semi-arid area. in this research to estimate of maximum allowable deficit (or: management allowed depletion) and irrigation scheduling of fodder mays based on canopy-air temperature difference, a field study was conducted in agricultural faculty of karaj. the lower limi...

Juvenile woody desert perennials often exhibit higher rates of transpiration than co-occurring adults, which may facilitate establishment by increasing carbon gain when water is plentiful, but increase the risk of hydraulic failure during drought. We tested three hypotheses regarding the role of hydraulic limits in two size classes of Larrea tridentata: 1) small plants grow faster and use more ...

The terrestrial hydrological cycle is strongly influenced by transpiration--water loss through the stomatal pores of leaves. In this report we present studies showing that the energy content of radiation absorbed by the leaf influences stomatal control of transpiration. This observation is at odds with current concepts of how stomata sense and control transpiration, and we suggest an alternativ...

Fruit water balance is determined by entry of sap through xylem and phloem, and losses due to back̄ow from fruits to other organs, and to transpiration. The latter, which may vary according to growing and climatic conditions, plays a signi®cant role in fruit water balance. To better understand and predict tomato fruit transpiration, measurements of the transpiration rate of shaded and nonshaded ...

Nighttime transpiration is a substantial portion of ecosystem water budgets, but few studies compare water use of closely related co-occurring species in a phylogenetic context. Nighttime transpiration can range up to 69% of daytime rates and vary between species, ecosystem, and functional type. We examined leaf-level daytime and nighttime gas exchange of five species of the genus Rubus co-occu...

Recent evidence from leaves and stems indicates that gradients in water potential (psi(w)) necessary for water movement through growing tissues are larger than previously assumed. Because growth is sensitive to tissue psi(w) and the behavior of these gradients has not been investigated in transpiring plants, we examined the water status of all the growing and mature vegetative tissues of maize ...