The planning of waste management facilities requires a study of design altematives including economic and environmental aspects to determine the optimal solution. Both landfill design and engineering are based on a ge...The planning of waste management facilities requires a study of design altematives including economic and environmental aspects to determine the optimal solution. Both landfill design and engineering are based on a geotechnical risk assessment namely in terms of the stability of the subsoil, the potential of mechanical deformation of the landfill body, and the stability of the interim and final cover considering also seismic events. This contribution introduces sites located in Romania and Estonia with a special focus on the geotechnical risk assessment in the design and construction of new landfills and the closure of old landfills. During the closure of a landfill an appropriate development of the interim cover is of high relevance for the remediation of old landfills, since the settlement processes in the landfill body must be decayed before the final cover can be applied. Depending on the proportion of biodegradable waste in the landfill body, the degree of compaction of the waste as well as the alteration and degree of mineralisation, the degree of the settlements can account for 5 to 15% of the landfill body height. The major settlements can generally last up to three years, depending on the organic inventory of the landfill. The examples from landfill engineering in Estonia and Romania illustrate the relevance of geotechnical assessments during the design phase of a landfill or a landfill closure as well as during the construction period.展开更多
In an arid environment, especially in sandy areas where surface runoff is of no practical importance in the hydrological budget, it is rainfall, dewfall and evapotranspiration that become the most important variables....In an arid environment, especially in sandy areas where surface runoff is of no practical importance in the hydrological budget, it is rainfall, dewfall and evapotranspiration that become the most important variables. To assess actual evapotranspiration, several methods （flux-gradient, BREB, eddy correlation） were applied to data from the Nizzana experimental site in the northwestern Negev Desert. Additionally, a model specifically designed for arid environments is introduced in this paper. This zero plane model shows the most reasonable results compared with the other methods, which overestimate evapotranspiration to a large degree. It is shown that plant transpiration is the dominant process in total evapotranspiration while advective processes do not play a major role in the near-ground boundary layer, although the study area is influenced by a sea breeze. Actual transpiration ofArtemisia monosperma was measured in a field experiment to validate the calculated evapotranspiration. The vegetation contributed 41% of the calculated total evapotranspiration in a single month.展开更多
A stochastic numerical approach was developed to model the actual standing biomass in the sand dunes of the northwestern Negev （Israel） and probable boundary conditions that may be responsible for the vegetation pat...A stochastic numerical approach was developed to model the actual standing biomass in the sand dunes of the northwestern Negev （Israel） and probable boundary conditions that may be responsible for the vegetation patterns investigated in detail. Our results for several variables characteristic for the prevailing climate, geomorphology, hydrology and biologicy at four measurement stations along a transect from northwest to southeast allowed for the development of a stochastic model for biomass distribution over the entire sand dune field （mesoscale） and at Nizzana experimental station （microscale）. With this equation it was possible to compute and interpolate a biomass index value for each grid point on the mesoscale and micro scale. The spatial distribution of biomass is negatively linked to distance from the sea, to rainfall and relief energy.展开更多
文摘The planning of waste management facilities requires a study of design altematives including economic and environmental aspects to determine the optimal solution. Both landfill design and engineering are based on a geotechnical risk assessment namely in terms of the stability of the subsoil, the potential of mechanical deformation of the landfill body, and the stability of the interim and final cover considering also seismic events. This contribution introduces sites located in Romania and Estonia with a special focus on the geotechnical risk assessment in the design and construction of new landfills and the closure of old landfills. During the closure of a landfill an appropriate development of the interim cover is of high relevance for the remediation of old landfills, since the settlement processes in the landfill body must be decayed before the final cover can be applied. Depending on the proportion of biodegradable waste in the landfill body, the degree of compaction of the waste as well as the alteration and degree of mineralisation, the degree of the settlements can account for 5 to 15% of the landfill body height. The major settlements can generally last up to three years, depending on the organic inventory of the landfill. The examples from landfill engineering in Estonia and Romania illustrate the relevance of geotechnical assessments during the design phase of a landfill or a landfill closure as well as during the construction period.
文摘In an arid environment, especially in sandy areas where surface runoff is of no practical importance in the hydrological budget, it is rainfall, dewfall and evapotranspiration that become the most important variables. To assess actual evapotranspiration, several methods （flux-gradient, BREB, eddy correlation） were applied to data from the Nizzana experimental site in the northwestern Negev Desert. Additionally, a model specifically designed for arid environments is introduced in this paper. This zero plane model shows the most reasonable results compared with the other methods, which overestimate evapotranspiration to a large degree. It is shown that plant transpiration is the dominant process in total evapotranspiration while advective processes do not play a major role in the near-ground boundary layer, although the study area is influenced by a sea breeze. Actual transpiration ofArtemisia monosperma was measured in a field experiment to validate the calculated evapotranspiration. The vegetation contributed 41% of the calculated total evapotranspiration in a single month.
文摘A stochastic numerical approach was developed to model the actual standing biomass in the sand dunes of the northwestern Negev （Israel） and probable boundary conditions that may be responsible for the vegetation patterns investigated in detail. Our results for several variables characteristic for the prevailing climate, geomorphology, hydrology and biologicy at four measurement stations along a transect from northwest to southeast allowed for the development of a stochastic model for biomass distribution over the entire sand dune field （mesoscale） and at Nizzana experimental station （microscale）. With this equation it was possible to compute and interpolate a biomass index value for each grid point on the mesoscale and micro scale. The spatial distribution of biomass is negatively linked to distance from the sea, to rainfall and relief energy.
