The water distribution system of one residential district in Tianjin is taken as an example to analyze the changes of water quality.Partial least squares(PLS) regression model,in which the turbidity and Fe are regarde...The water distribution system of one residential district in Tianjin is taken as an example to analyze the changes of water quality.Partial least squares(PLS) regression model,in which the turbidity and Fe are regarded as control objectives,is used to establish the statistical model.The experimental results indicate that the PLS regression model has good predicted results of water quality compared with the monitored data.The percentages of absolute relative error(below 15%,20%,30%) are 44.4%,66.7%,100%(turbidity) and 33.3%,44.4%,77.8%(Fe) on the 4th sampling point;77.8%,88.9%,88.9%(turbidity) and 44.4%,55.6%,66.7%(Fe) on the 5th sampling point.展开更多
In order to reduce the quantity of water applied by irrigation, increase the water use efficiency and determine the appropriate period for irrigation potato crop, a field experiment was implemented at vegetables field...In order to reduce the quantity of water applied by irrigation, increase the water use efficiency and determine the appropriate period for irrigation potato crop, a field experiment was implemented at vegetables field, Department of Plant Production, Agriculture Technical College, Mosul, Iraq, during spring season of 2014. This study involved four irrigation intervals （3, 4, 5 and 6 d） under drip irrigation system, with spraying by five antitranspirant substances （control, kaolin 5 g/L, MgCO3 3 g/L, liquid paraffin 2% and Nu-film 17 1%）, which subjected in a factorial experiment within split plot system in a randomized complete block design with three replications. The results showed that increasing irrigation intervals from 3 d to 6 d decreased the total water content of the leaves from 83.59% to 81.81%, the rate of relative transpiration from 0.174% to 0.162%, stomata area from 1.620 lam2/stomata to 0.921 ~m2/stomata, plant yield from 542.22 g to 425.80 g, total yield of tubers from 25.808 tons/ha to 20.253 tons/ha and marketable yield of tubers from 24.471 tons/ha to 18.822 tons/ha, whereas caused an increase in the leaf water deficit from 19.19% to 23.86% and water use efficiency from 8.63 kg/m3 to 13.32 kg/m3. Spraying potato plants with liquid paraffin 2% led to the highest total water content 83.37%, stomata area 1.466 ~tm2/stomata, the lowest relative transpiration 0.152%, the lowest leaf water deficit 20.33%, the highest plant yield 509.22 g, total yield 24.236 tons/ha, marketable yield 22.770 tons/ha and water use efficiency I 1.83 kg/m3. On the other hand, the interaction treatments between irrigation intervals and antitranspirants resulted in a significant effect in many studied parameters.展开更多
This paper proposes an on-site monitoring system for evaporation （Ew） and evapotranspiration （ET） in wetlands called the Compensation Evapotranspiration Observation System. Considering the characteristics of wetla...This paper proposes an on-site monitoring system for evaporation （Ew） and evapotranspiration （ET） in wetlands called the Compensation Evapotranspiration Observation System. Considering the characteristics of wetlands environment and emergent plants, the vertical flux of water loss in wetlands can be separated using the system based on compensation principle. A comparison research on water loss through ET in reed （Phragmites australis） stands between Zhalong wetland and Baiyangdian wetland was carded out in 2004-2009. In Baiyangdian wetland, the ET rates from three reed stands with different leaf area indexes were measured. The results show that annual ET in Zhalong wetland was 739-886 mm during study period. Comparatively, annual ET of the three reed stands in Baiyangdian wetland was 970-1117 mm, 1261-1452 mm and 1759-2035 ram, respectively. The ET rates in Baiyangdian were stronger than in Zhalong because of the effects of geography and climate characteristics. Moreover, seasonal dynamic changes and influence factors of transpiration-acting factor from the two wetlands were also analyzed. It is indicated that the transpirafion-actng factor can be affected by geographic location, aboveground biomass, plant growth and climate conditions.展开更多
基金Supported by National Natural Science Foundation of China (No.50478086)Tianjin Special Scientific Innovation Foundation (No.06FZZDSH00900)
文摘The water distribution system of one residential district in Tianjin is taken as an example to analyze the changes of water quality.Partial least squares(PLS) regression model,in which the turbidity and Fe are regarded as control objectives,is used to establish the statistical model.The experimental results indicate that the PLS regression model has good predicted results of water quality compared with the monitored data.The percentages of absolute relative error(below 15%,20%,30%) are 44.4%,66.7%,100%(turbidity) and 33.3%,44.4%,77.8%(Fe) on the 4th sampling point;77.8%,88.9%,88.9%(turbidity) and 44.4%,55.6%,66.7%(Fe) on the 5th sampling point.
文摘In order to reduce the quantity of water applied by irrigation, increase the water use efficiency and determine the appropriate period for irrigation potato crop, a field experiment was implemented at vegetables field, Department of Plant Production, Agriculture Technical College, Mosul, Iraq, during spring season of 2014. This study involved four irrigation intervals （3, 4, 5 and 6 d） under drip irrigation system, with spraying by five antitranspirant substances （control, kaolin 5 g/L, MgCO3 3 g/L, liquid paraffin 2% and Nu-film 17 1%）, which subjected in a factorial experiment within split plot system in a randomized complete block design with three replications. The results showed that increasing irrigation intervals from 3 d to 6 d decreased the total water content of the leaves from 83.59% to 81.81%, the rate of relative transpiration from 0.174% to 0.162%, stomata area from 1.620 lam2/stomata to 0.921 ~m2/stomata, plant yield from 542.22 g to 425.80 g, total yield of tubers from 25.808 tons/ha to 20.253 tons/ha and marketable yield of tubers from 24.471 tons/ha to 18.822 tons/ha, whereas caused an increase in the leaf water deficit from 19.19% to 23.86% and water use efficiency from 8.63 kg/m3 to 13.32 kg/m3. Spraying potato plants with liquid paraffin 2% led to the highest total water content 83.37%, stomata area 1.466 ~tm2/stomata, the lowest relative transpiration 0.152%, the lowest leaf water deficit 20.33%, the highest plant yield 509.22 g, total yield 24.236 tons/ha, marketable yield 22.770 tons/ha and water use efficiency I 1.83 kg/m3. On the other hand, the interaction treatments between irrigation intervals and antitranspirants resulted in a significant effect in many studied parameters.
基金supported by the National Natural Science Foundation of China (Grant No. 50139020)the National Basic Research Program of China ("973" Program) (Grant No. 2006CB403405)
文摘This paper proposes an on-site monitoring system for evaporation （Ew） and evapotranspiration （ET） in wetlands called the Compensation Evapotranspiration Observation System. Considering the characteristics of wetlands environment and emergent plants, the vertical flux of water loss in wetlands can be separated using the system based on compensation principle. A comparison research on water loss through ET in reed （Phragmites australis） stands between Zhalong wetland and Baiyangdian wetland was carded out in 2004-2009. In Baiyangdian wetland, the ET rates from three reed stands with different leaf area indexes were measured. The results show that annual ET in Zhalong wetland was 739-886 mm during study period. Comparatively, annual ET of the three reed stands in Baiyangdian wetland was 970-1117 mm, 1261-1452 mm and 1759-2035 ram, respectively. The ET rates in Baiyangdian were stronger than in Zhalong because of the effects of geography and climate characteristics. Moreover, seasonal dynamic changes and influence factors of transpiration-acting factor from the two wetlands were also analyzed. It is indicated that the transpirafion-actng factor can be affected by geographic location, aboveground biomass, plant growth and climate conditions.
