针对山洪灾害临界雨量单一值预警预报精度偏低问题,将雨型不确定性纳入考虑范围之内,依据基因变异原理,提出了种群雨型生成方法,并将HEC-HMS模型引入到临界雨量计算模型,计算了新县流域6h临界雨量阈值空间,绘制了R-G-H临界雨量预警图,...针对山洪灾害临界雨量单一值预警预报精度偏低问题,将雨型不确定性纳入考虑范围之内,依据基因变异原理,提出了种群雨型生成方法,并将HEC-HMS模型引入到临界雨量计算模型,计算了新县流域6h临界雨量阈值空间,绘制了R-G-H临界雨量预警图,从概念-物理机制-分析判断-发布预警对山洪预警工作进行了系统梳理。结果表明:研究区G P,6雨型种群对应临界雨量阈值空间为84~161mm,最大变幅为91.7%;随着主变异基因位置g r的后移,临界雨量呈现出逐渐减小趋势;G 5雨型集不易控制,致灾情景多变,临界雨量最大变幅为24.5%;在Pa=0.2 W m、Pa=0.5 W m、Pa=0.8 W m时,研究区6h临界雨量阈值空间分别为100~161mm、96~145mm、84~121mm。通过对成灾情景的识别,选择合理阈值发布预警信息,可有效提高山洪灾害预警精度。展开更多
Climate change and Land Use/Cover Change（LUCC） have been identified as two primary factors affecting watershed hydrological regime. This study analyzed the trends of streamflow, precipitation, air temperature and po...Climate change and Land Use/Cover Change（LUCC） have been identified as two primary factors affecting watershed hydrological regime. This study analyzed the trends of streamflow, precipitation, air temperature and potential evapotranspiration（PET） from 1962 to 2008 in the Jihe watershed in northwestern Loess Plateau of China using the Mann-Kendall test. The streamflow responses to climate change and LUCC were quantified independently by the elasticity method. The results show that the streamflow presented a dramatic decline with a turning point occurred in 1971, while the precipitation and PET did not change significantly. The results also show that the temperature rose markedly especially since 1990 s with an approximate increase of 1.74°C over the entire research period（1962–2008）. Using land use transition matrix, we found that slope cropland was significantly converted to terrace between 1970 s and 1990 s and that forest cover increased relatively significantly because of the Grain for Green Project after 2000. The streamflow reduction was predominantly caused by LUCC and its contribution reached up to 90.2%, while the contribution of climate change to streamflow decline was only 9.8%. Although the analytical results between the elasticity method and linear regression model were not satisfactorily consistent, they both indicated that LUCC（human activity） was the major factor causing streamflow decline in the Jihe watershed from 1962 to 2008.展开更多
文摘针对山洪灾害临界雨量单一值预警预报精度偏低问题,将雨型不确定性纳入考虑范围之内,依据基因变异原理,提出了种群雨型生成方法,并将HEC-HMS模型引入到临界雨量计算模型,计算了新县流域6h临界雨量阈值空间,绘制了R-G-H临界雨量预警图,从概念-物理机制-分析判断-发布预警对山洪预警工作进行了系统梳理。结果表明:研究区G P,6雨型种群对应临界雨量阈值空间为84~161mm,最大变幅为91.7%;随着主变异基因位置g r的后移,临界雨量呈现出逐渐减小趋势;G 5雨型集不易控制,致灾情景多变,临界雨量最大变幅为24.5%;在Pa=0.2 W m、Pa=0.5 W m、Pa=0.8 W m时,研究区6h临界雨量阈值空间分别为100~161mm、96~145mm、84~121mm。通过对成灾情景的识别,选择合理阈值发布预警信息,可有效提高山洪灾害预警精度。
基金funded by the National Natural Science Foundation of China (41501025, 51609083, 41401038, 51509089)the 2016 Key Scientific Research Projects for Universities of Henan Province (16A170014)
文摘Climate change and Land Use/Cover Change（LUCC） have been identified as two primary factors affecting watershed hydrological regime. This study analyzed the trends of streamflow, precipitation, air temperature and potential evapotranspiration（PET） from 1962 to 2008 in the Jihe watershed in northwestern Loess Plateau of China using the Mann-Kendall test. The streamflow responses to climate change and LUCC were quantified independently by the elasticity method. The results show that the streamflow presented a dramatic decline with a turning point occurred in 1971, while the precipitation and PET did not change significantly. The results also show that the temperature rose markedly especially since 1990 s with an approximate increase of 1.74°C over the entire research period（1962–2008）. Using land use transition matrix, we found that slope cropland was significantly converted to terrace between 1970 s and 1990 s and that forest cover increased relatively significantly because of the Grain for Green Project after 2000. The streamflow reduction was predominantly caused by LUCC and its contribution reached up to 90.2%, while the contribution of climate change to streamflow decline was only 9.8%. Although the analytical results between the elasticity method and linear regression model were not satisfactorily consistent, they both indicated that LUCC（human activity） was the major factor causing streamflow decline in the Jihe watershed from 1962 to 2008.
