Search results for "WATER BALANCE"

Hydrogeochemistry and Water Balance in the Coastal Wetland Area of “Biviere di Gela,” Sicily, Italy

2006

In the study area physical and chemical factors control the composition of surface and groundwaters, which in turn determine the water quality of the "Biviere di Gela" lake. These factors combine to create diverse water types which change their compositional character spatially as rainfall infiltrates the soil zone, moves down a topographically defined flow path, and interacts with bedrock minerals. Low-salinity waters, which represent the initial stage of underground circulation, start dissolving calcium carbonate from the local rocks. The progressive increase in salinity, characterized by substantially higher Ca, SO4, Na and Cl concentrations, suggests that dissolution of CaSO4 and NaCl i…

The regional park of the Nebrodi Mts. (Sicily): a contribution to an integrated groundwater management

1998

The Nebrodi Park, located in the north-eastern sector of Sicily, is of particular environmental and scientific interest. This is due to the morphological heterogeneity of the protected region that presents a wide variety of landscapes and ecosystems. In spite of the recent efforts of the Regional Government and Municipalities, environmental resources, especially groundwater, risk progressive depauperation and pollution. In this paper, the authors consider the hydrogeological karst unit of Monte Traura-Rocche del Crasto, the most productive in the Nebrodi belt (zone B of the regional park). This unit is underexploited and needs a careful hydrogeological study in order to supply coastal aquif…

Geochemical insight into differences in the physical structures and dynamics of two adjacent maar lakes at Mt. Vulture volcano (southern Italy)

2013

[1] We report on the first geochemical investigation of the Monticchio maar lakes (Mt. Vulture volcano, southern Italy) covering an annual cycle that aimed at understanding the characteristic features of the physical structures and dynamics of the two lakes. We provide the first detailed description of the lakes based on high-resolution conductivity-temperature-depth (CTD) profiles, chemical and isotopic (H and O) compositions of the water, and the amounts of dissolved gases (e.g., He, Ar, CH4, and CO2). The combined data set reveals that the two lakes, which are separated by less than 200 m, exhibit different dynamics: one is a meromictic lake, where the waters are rich in biogenic and man…

A conceptual dynamic vegetation-soil model for arid and semiarid zones

2007

Plant ecosystems in arid and semiarid zones show high complexity from the point of view of water resources, since they depend on water availability to carry out their vital processes. In these climates, water stress is the main factor controlling vegetation development. The available water in the system results from a water balance where the soil, vegetation and the atmosphere are the key issues; but it is the vegetation which modulates (to a great extent) the total balance of water and the mechanisms of the feedback between soil and atmosphere, being the knowledge about soil moisture quite relevant for assessing available water and, as a consequence, for growth and plants maintenance and t…

Comparison of evapotranspiration estimates by NOAA-AVHRR images and aircraft flux measurements in a semiarid region of Spain.

1998

Abstract This paper is intended to show how to aggregate two different remote-sensing techniques carried out in the framework of the European-Union funded project EFEDA (European Field Experiment in a Desertification-threatened Area). One of these is based on satellite measurements, and the other on aircraft flux measurements. The aim of putting together both methodologies was to determine regional evapotranspiration as a major component of the water balance in Castilla-La Mancha, a semiarid region in southeast Spain. The basis for the satellite approach is using temperature information collected by the Advanced Very High-Resolution Radio- meter (AVHRR) sensor on board the National Oceanic …

Fluorescence explorer (FLEX): An optimised payload to map vegetation photosynthesis from space

2006

The FLuorescence EXplorer (FLEX) mission proposes to launch a satellite for the global monitoring of steady-state chlorophyll fluorescence in terrestrial vegetation. Fluorescence is a sensitive probe of photosynthetic function in both healthy and physiologically perturbed vegetation, and a powerful non-invasive tool to track the status, resilience, and recovery of photochemical processes and moreover provides important information on overall photosynthetic performance with implications for related carbon sequestration. The early responsiveness of fluorescence to atmospheric, soil and plant water balance, as well as to atmospheric chemistry and human intervention in land usage makes it an ob…

Comparison between energy balance and mass balance models for actual evapotranspiration assessment

2009

The assessment of the water needs for a specific crop has a fundamental importance in the management of water resources. The application of empirical models able to retrieve estimates of the actual evapotranspiration (ETa) to assess the need for water could give a valid tool for the planning of water supply, avoiding unnecessary water losses. In this context, two independent models for estimating actual evapotranspiration were compared. The first model is based on an energy balance and uses remotely sensed data and ancillary data from weather stations to assess the ETa. The second model also uses remotely sensed data and climatic data on a daily basis from a weather network. Field measureme…

Estimation of actual evapotranspiration of Mediterranean perennial crops by means of remote-sensing based surface energy balance models

2009

Abstract. Actual evapotranspiration from typical Mediterranean crops has been assessed in a Sicilian study area by using surface energy balance (SEB) and soil-water balance models. Both modelling approaches use remotely sensed data to estimate evapotranspiration fluxes in a spatially distributed way. The first approach exploits visible (VIS), near-infrared (NIR) and thermal (TIR) observations to solve the surface energy balance equation whereas the soil-water balance model uses only VIS-NIR data to detect the spatial variability of crop parameters. Considering that the study area is characterized by typical spatially sparse Mediterranean vegetation, i.e. olive, citrus and vineyards, alterna…

Assessing the agro hydrological SWAP model to simulate soil water balance in typical Mediterranean crops

2007

Pollutant removal efficiency of a pilot-scale Horizontal Subsurface Flow in Sicily (Italy) planted with Cyperus alternifolius L. and Typha latifolia …

2016

Constructed wetland systems (CWs) are developed biological technologies for the treatment and reuse of wastewater. The aims of this study were to evaluate the treatment performance of a pilot Horizontal Subsurface Flow system (HSSFs), to evaluate the reuse of treated wastewater (TWW) from CWs for the irrigation of giant reed (Arundo donax (L.)) and to assess the effects of TWW on the biomass yield of giant reed grown for pellet production. The research was carried out in Sicily (Italy) in a pilot-scale HSSFs which was fed with urban-treated urban wastewater following secondary treatment from an activated sludge wastewater treatment plant. Giant reed plots were irrigated with TWW from plante…