A set of field experiments was conducted to investigate the effects of reed rootstocks on hydraulic properties of surface soils in the Shuangtai Estuary Wetland, Northeast China. The soil particle size distribution an...A set of field experiments was conducted to investigate the effects of reed rootstocks on hydraulic properties of surface soils in the Shuangtai Estuary Wetland, Northeast China. The soil particle size distribution and rootstock content were analyzed, and the vertical soil water profile was monitored by using a multisensory capacitance system. Hydraulic conductivity of the surface soil layer was estimated by in si-tu infiltration. The soil was silt loam with less sand; soil texture was consistent though the vertical profile, but bulk density was lower in the upper 20 era, where the fine roots were concentrated. The surface soil moisture profile changed dynamically, and variation in vertically integrated soil moisture was consistent with observed precipitation and estimated evaporation. Infiltration capacity was 30 cm＇d＂~, much larger than typical hydraulic conductivity values for silt loam with less sand. These findings suggest that fine annual roots change the soil matrix and hydraulic conductivity in surface soils. A vertical one-dimensional water transport model was presented based on Richard＇s equation. Model parameters were estimated from the soil analyses and literature data. The computation accurately reproduced the dynamic changes in moisture in surface soils containing large volumes of fine rootstock.展开更多
Dynamic numerical simulation of water conditions is useful for reservoir management. In remote semi-arid areas, however, meteorological and hydrological time-series data needed for computation are not frequently measu...Dynamic numerical simulation of water conditions is useful for reservoir management. In remote semi-arid areas, however, meteorological and hydrological time-series data needed for computation are not frequently measured and must be obtained using other information. This paper presents a case study of data generation for the computation of thermal conditions in the Joumine Reservoir, Tunisia. Data from the Wind Finder web site and daily sunshine duration at the nearest weather stations were utilized to generate cloud cover and solar radiation data based on meteorological correlations obtained in Japan, which is located at the same latitude as Tunisia. A time series of inflow water temperature was estimated from air temperature using a numerical filter expressed as a linear second-order differential equation. A numerical simulation using a vertical 2-D （two-dimensional） turbulent flow model for a stratified water body with generated data successfully reproduced seasonal thermal conditions in the reservoir, which were monitored using a thermistor chain.展开更多
文摘A set of field experiments was conducted to investigate the effects of reed rootstocks on hydraulic properties of surface soils in the Shuangtai Estuary Wetland, Northeast China. The soil particle size distribution and rootstock content were analyzed, and the vertical soil water profile was monitored by using a multisensory capacitance system. Hydraulic conductivity of the surface soil layer was estimated by in si-tu infiltration. The soil was silt loam with less sand; soil texture was consistent though the vertical profile, but bulk density was lower in the upper 20 era, where the fine roots were concentrated. The surface soil moisture profile changed dynamically, and variation in vertically integrated soil moisture was consistent with observed precipitation and estimated evaporation. Infiltration capacity was 30 cm＇d＂~, much larger than typical hydraulic conductivity values for silt loam with less sand. These findings suggest that fine annual roots change the soil matrix and hydraulic conductivity in surface soils. A vertical one-dimensional water transport model was presented based on Richard＇s equation. Model parameters were estimated from the soil analyses and literature data. The computation accurately reproduced the dynamic changes in moisture in surface soils containing large volumes of fine rootstock.
文摘Dynamic numerical simulation of water conditions is useful for reservoir management. In remote semi-arid areas, however, meteorological and hydrological time-series data needed for computation are not frequently measured and must be obtained using other information. This paper presents a case study of data generation for the computation of thermal conditions in the Joumine Reservoir, Tunisia. Data from the Wind Finder web site and daily sunshine duration at the nearest weather stations were utilized to generate cloud cover and solar radiation data based on meteorological correlations obtained in Japan, which is located at the same latitude as Tunisia. A time series of inflow water temperature was estimated from air temperature using a numerical filter expressed as a linear second-order differential equation. A numerical simulation using a vertical 2-D （two-dimensional） turbulent flow model for a stratified water body with generated data successfully reproduced seasonal thermal conditions in the reservoir, which were monitored using a thermistor chain.
