The flooding caused by heavy rainfall in rice irrigation area and the drought caused by the drop of groundwater level are the research focus in the field of irrigation and drainage.Based on the comparative experiment ...The flooding caused by heavy rainfall in rice irrigation area and the drought caused by the drop of groundwater level are the research focus in the field of irrigation and drainage.Based on the comparative experiment and farmland water level control technology,this paper studied the average soil temperature under different soil layers(TM),the daily temperature change(TDC),the photosynthetic accumulation of single leaf and canopy in rice,and response of photothermal energy to rice root characteristics and growth factors in the paddy field under drought conditions.The results showed that the peak soil temperature under drought treatment was basically synchronous with the conventional irrigation,and the it was delayed by 2–6 h under flooding treatment compared to the drought treatment.Under different water gradients,the temperature decreased according to T_(L)>T_(CK)>T_(H)(L,H and CK represented water flooding,drought and control treatments),and the TDC was opposite.In addition to milky stage,the daily photosynthetic(Pn)accumulation of single leaf and canopy in the flooding and drought treated paddy fields were lower than conventional irrigation,and had a negative impact on leaf area index(LAI)and yield(YR),but did not form fatal damage.The root characteristic factors,RL(root length),RW(root weight),R-CR(root-canopy ratio)were promoted with drought,and YR under light drought was slightly higher than that under heavy drought.There was a strong positive correlation between TM and R-CR in all rice growth stages,while TDC-5 was negatively correlated with effective panicle number,TDC and R-CR in 20 cm soil layer were positively correlated.The correlation between daily Pn accumulation and YR was low,and the correlation between Pn and YR factors was negative or weak positive or negative.The total Pn was positively correlated with yield factors,and the correlation coefficient was higher than that of daily Pn.展开更多
On the basis of discussing the influencing mode of plant moisture stress on plant physiological process and the division of soil moisture availability range, the water suction values partitioning soil moisture were pu...On the basis of discussing the influencing mode of plant moisture stress on plant physiological process and the division of soil moisture availability range, the water suction values partitioning soil moisture were put forward, and then the corresponding water moistures under water stress were obtained by conversing together with characteristic curve of water moisture.展开更多
以黄河上游多年调节水库龙羊峡及下游刘家峡水库为研究对象,考虑来水不确定性影响,建立梯级水库群多目标随机优化模型,并基于理想点法(technique for order preference by similarity to an ideal solution,TOPSIS)决策方法,求解当年发...以黄河上游多年调节水库龙羊峡及下游刘家峡水库为研究对象,考虑来水不确定性影响,建立梯级水库群多目标随机优化模型,并基于理想点法(technique for order preference by similarity to an ideal solution,TOPSIS)决策方法,求解当年发电量与年末水位Pareto方案集中最佳方案,探讨来水频率及起调水位对年末水位和发电量的影响,验证年末期望水位保证多年调节水库发电效益的可靠性。结果表明:在不确定来水条件下,龙羊峡水库年末期望水位与龙羊峡水库、刘家峡水库年期望发电量之间存在竞争关系;龙羊峡水库来水频率越低、起调水位越高时,龙羊峡水库年末水位越高,龙羊峡水库、刘家峡水库发电量越大;基于提出的年末水位优化方法可大幅缩减龙羊峡水库现行调度方式下年末水位范围,且保障发电效益的可靠性在98%以上。展开更多
基金National Key Research and Development Program(2019YFC0408803)Basic Public Welfare Research Project of Zhejiang Province(LGN20E090001)+2 种基金Major scientific and technological projects of Zhejiang Provincial Department of water resources(RA1913)Water conservancy science and technology in Zhejiang Province(RC1918,RC2029),National Natural Science Foundation of China(52009044)High-level Talent Research Project of North China University of Water Resources and Electric Power(201705017).
文摘The flooding caused by heavy rainfall in rice irrigation area and the drought caused by the drop of groundwater level are the research focus in the field of irrigation and drainage.Based on the comparative experiment and farmland water level control technology,this paper studied the average soil temperature under different soil layers(TM),the daily temperature change(TDC),the photosynthetic accumulation of single leaf and canopy in rice,and response of photothermal energy to rice root characteristics and growth factors in the paddy field under drought conditions.The results showed that the peak soil temperature under drought treatment was basically synchronous with the conventional irrigation,and the it was delayed by 2–6 h under flooding treatment compared to the drought treatment.Under different water gradients,the temperature decreased according to T_(L)>T_(CK)>T_(H)(L,H and CK represented water flooding,drought and control treatments),and the TDC was opposite.In addition to milky stage,the daily photosynthetic(Pn)accumulation of single leaf and canopy in the flooding and drought treated paddy fields were lower than conventional irrigation,and had a negative impact on leaf area index(LAI)and yield(YR),but did not form fatal damage.The root characteristic factors,RL(root length),RW(root weight),R-CR(root-canopy ratio)were promoted with drought,and YR under light drought was slightly higher than that under heavy drought.There was a strong positive correlation between TM and R-CR in all rice growth stages,while TDC-5 was negatively correlated with effective panicle number,TDC and R-CR in 20 cm soil layer were positively correlated.The correlation between daily Pn accumulation and YR was low,and the correlation between Pn and YR factors was negative or weak positive or negative.The total Pn was positively correlated with yield factors,and the correlation coefficient was higher than that of daily Pn.
文摘On the basis of discussing the influencing mode of plant moisture stress on plant physiological process and the division of soil moisture availability range, the water suction values partitioning soil moisture were put forward, and then the corresponding water moistures under water stress were obtained by conversing together with characteristic curve of water moisture.
文摘以黄河上游多年调节水库龙羊峡及下游刘家峡水库为研究对象,考虑来水不确定性影响,建立梯级水库群多目标随机优化模型,并基于理想点法(technique for order preference by similarity to an ideal solution,TOPSIS)决策方法,求解当年发电量与年末水位Pareto方案集中最佳方案,探讨来水频率及起调水位对年末水位和发电量的影响,验证年末期望水位保证多年调节水库发电效益的可靠性。结果表明:在不确定来水条件下,龙羊峡水库年末期望水位与龙羊峡水库、刘家峡水库年期望发电量之间存在竞争关系;龙羊峡水库来水频率越低、起调水位越高时,龙羊峡水库年末水位越高,龙羊峡水库、刘家峡水库发电量越大;基于提出的年末水位优化方法可大幅缩减龙羊峡水库现行调度方式下年末水位范围,且保障发电效益的可靠性在98%以上。
