Evapotranspiration is the most important expenditure item in the water balance of terrestrial ecosystems,and accurate evapotranspiration modeling is of great significance for hydrological,ecological,agricultural,and w...Evapotranspiration is the most important expenditure item in the water balance of terrestrial ecosystems,and accurate evapotranspiration modeling is of great significance for hydrological,ecological,agricultural,and water resource management.Artificial forests are an important means of vegetation restoration in the western Loess Plateau,and accurate estimates of their evapotranspiration are essential to the management and development of water use strategies for artificial forests.This study estimated the soil moisture and evapotranspiration based on the HYDRUS-1D model for the artificial Platycladus orientalis(L.)Franco forest in western mountains of Loess Plateau,China from 20 April to 31 October,2023.Moreover,the influence factors were identified by combining the correlation coefficient method and the principal component analysis(PCA)method.The results showed that HYDRUS-1D model had strong applicability in portraying hydrological processes in this area and revealed soil water surplus from 20 April to 31 October,2023.The soil water accumulation was 49.64 mm;the potential evapotranspiration(ETp)was 809.67 mm,which was divided into potential evaporation(Ep;95.07 mm)and potential transpiration(Tp;714.60 mm);and the actual evapotranspiration(ETa)was 580.27 mm,which was divided into actual evaporation(Ea;68.27 mm)and actual transpiration(Ta;512.00 mm).From April to October 2023,the ETp,Ep,Tp,ETa,Ea,and Ta first increased and then decreased on both monthly and daily scales,exhibiting a single-peak type trend.The average ratio of Ta/ETa was 0.88,signifying that evapotranspiration mainly stemmed from transpiration in this area.The ratio of ETa/ETp was 0.72,indicating that this artificial forest suffered from obvious drought stress.The ETp was significantly positively correlated with ETa,and the R2 values on the monthly and daily scales were 0.9696 and 0.9635(P<0.05),respectively.Furthermore,ETa was significantly positively correlated with temperature,solar radiation,and wind speed,and negatively correlated with relative humidity and precipitation(P<0.05);and temperature exhibited the highest correlation with ETa.Thus,ETp and temperature were the decisive contributors to ETa in this area.The findings provide an effective method for simulating regional evapotranspiration and theoretical reference for water management of artificial forests,and deepen understanding of effects of each influence factors on ETa in arid areas.展开更多
Both physical and chemical processes affect the fate and transport of herbicides. It is useful to simulate these processes with computer programs to predict solute movement. Simulations were run with HYDRUS- 1 D to id...Both physical and chemical processes affect the fate and transport of herbicides. It is useful to simulate these processes with computer programs to predict solute movement. Simulations were run with HYDRUS- 1 D to identify the sorption and degradation parameters of atrazine through calibration from the breakthrough curves （BTCs）. Data from undisturbed and disturbed soil column experiments were compared and analyzed using the dual-porosity model. The study results show that the values of dispersivity are slightly lower in disturbed columns, suggesting that the more heterogeneous the structure is, the higher the dispersivity. Sorption parameters also show slight variability, which is attributed to the differences in soil properties, experimental conditions and methods, or other ecological factors. For both of the columns, the degradation rates were similar. Potassium bromide was used as a conservative non-reactive tracer to characterize the water movement in columns. Atrazine BTCs exhibited significant tailing and asymmetry, indicating non-equilibrium sorption during solute transport. The dual-porosity model was verified to best fit the BTCs of the column experiments. Greater or lesser concentration of atrazine spreading to the bottom of the columns indicated risk of groundwater contamination. Overall, HYDRUS-1D successfully simulated the atrazine transport in soil columns.展开更多
基金financially supported by the National Natural Science Foundation of China(42071047,41771035)the Basic Research Innovation Group Project of Gansu Province(22JR5RA129)the Excellent Doctoral Program in Gansu Province(24JRRA152).
文摘Evapotranspiration is the most important expenditure item in the water balance of terrestrial ecosystems,and accurate evapotranspiration modeling is of great significance for hydrological,ecological,agricultural,and water resource management.Artificial forests are an important means of vegetation restoration in the western Loess Plateau,and accurate estimates of their evapotranspiration are essential to the management and development of water use strategies for artificial forests.This study estimated the soil moisture and evapotranspiration based on the HYDRUS-1D model for the artificial Platycladus orientalis(L.)Franco forest in western mountains of Loess Plateau,China from 20 April to 31 October,2023.Moreover,the influence factors were identified by combining the correlation coefficient method and the principal component analysis(PCA)method.The results showed that HYDRUS-1D model had strong applicability in portraying hydrological processes in this area and revealed soil water surplus from 20 April to 31 October,2023.The soil water accumulation was 49.64 mm;the potential evapotranspiration(ETp)was 809.67 mm,which was divided into potential evaporation(Ep;95.07 mm)and potential transpiration(Tp;714.60 mm);and the actual evapotranspiration(ETa)was 580.27 mm,which was divided into actual evaporation(Ea;68.27 mm)and actual transpiration(Ta;512.00 mm).From April to October 2023,the ETp,Ep,Tp,ETa,Ea,and Ta first increased and then decreased on both monthly and daily scales,exhibiting a single-peak type trend.The average ratio of Ta/ETa was 0.88,signifying that evapotranspiration mainly stemmed from transpiration in this area.The ratio of ETa/ETp was 0.72,indicating that this artificial forest suffered from obvious drought stress.The ETp was significantly positively correlated with ETa,and the R2 values on the monthly and daily scales were 0.9696 and 0.9635(P<0.05),respectively.Furthermore,ETa was significantly positively correlated with temperature,solar radiation,and wind speed,and negatively correlated with relative humidity and precipitation(P<0.05);and temperature exhibited the highest correlation with ETa.Thus,ETp and temperature were the decisive contributors to ETa in this area.The findings provide an effective method for simulating regional evapotranspiration and theoretical reference for water management of artificial forests,and deepen understanding of effects of each influence factors on ETa in arid areas.
基金the China Harbor Engineering Company (CHEC) for providing financial support
文摘Both physical and chemical processes affect the fate and transport of herbicides. It is useful to simulate these processes with computer programs to predict solute movement. Simulations were run with HYDRUS- 1 D to identify the sorption and degradation parameters of atrazine through calibration from the breakthrough curves （BTCs）. Data from undisturbed and disturbed soil column experiments were compared and analyzed using the dual-porosity model. The study results show that the values of dispersivity are slightly lower in disturbed columns, suggesting that the more heterogeneous the structure is, the higher the dispersivity. Sorption parameters also show slight variability, which is attributed to the differences in soil properties, experimental conditions and methods, or other ecological factors. For both of the columns, the degradation rates were similar. Potassium bromide was used as a conservative non-reactive tracer to characterize the water movement in columns. Atrazine BTCs exhibited significant tailing and asymmetry, indicating non-equilibrium sorption during solute transport. The dual-porosity model was verified to best fit the BTCs of the column experiments. Greater or lesser concentration of atrazine spreading to the bottom of the columns indicated risk of groundwater contamination. Overall, HYDRUS-1D successfully simulated the atrazine transport in soil columns.
