Crop consumptive water use is recognized as a key element to understand regional water management performance. This study documents an attempt to apply a regional evapotranspiration model（SEBAL） and crop information...Crop consumptive water use is recognized as a key element to understand regional water management performance. This study documents an attempt to apply a regional evapotranspiration model（SEBAL） and crop information for assessment of regional crop（summer maize and winter wheat） actual evapotranspiration（ET a） in Huang-Huai-Hai（3H） Plain, China. The average seasonal ET a of summer maize and winter wheat were 354.8 and 521.5 mm respectively in 3H Plain. A high-ET a belt of summer maize occurs in piedmont plain, while a low ET a area was found in the hill-irrigable land and dry land area. For winter wheat, a high-ET a area was located in the middle part of 3H Plain, including low plain-hydropenia irrigable land and dry land, hill-irrigable land and dry land, and basin-irrigable land and dry land. Spatial analysis demonstrated a linear relationship between crop ET a, normalized difference vegetation index（NDVI）, and the land surface temperature（LST）. A stronger relationship between ET a and NDVI was found in the metaphase and last phase than other crop growing phase, as indicated by higher correlation coefficient values. Additionally, higher correlation coefficients were detected between ET a and LST than that between ET a and NDVI, and this significant relationship ran through the entire crop growing season. ET a in the summer maize growing season showed a significant relationship with longitude, while ET a in the winter wheat growing season showed a significant relationship with latitude. The results of this study will serve as baseline information for water resources management of 3H Plain.展开更多
This paper deliberates on the issue of water consumption (evapotranspiration, ET) of three main crops in North China: wheat, corn and bean, which is mainly related to three factors as indicated by the definition of SP...This paper deliberates on the issue of water consumption (evapotranspiration, ET) of three main crops in North China: wheat, corn and bean, which is mainly related to three factors as indicated by the definition of SPAC system. Water consumption was measured on daily and sometimes hourly basis by Lysimeter, which can be adjusted to have the same groundwater level as that in the field, thus the measurement could serve as representative of crop water consumption for adjacent area. The consumption period for three crops has been analyzed and cumulative deviation from the mean of daily evapotranspiration been used to divide the whole growing period into several parts, which are related to but different from the growing periods. The serial correlation coefficients for varied lag time have been calculated to verify that the process of daily ET is not random, and therefore the cumulative daily consumption has been simulated by polynomial method, which gives relative good results. Finally, the effort has been made to investigate the relation of crop yield and water consumption and water use efficiency based on a time series of seven years.展开更多
基金supported by the National Key Technologies R&D Program of China during the 12th Five-Year Plan period (2012BAD09B01)the National Basic Research Program of China (973 Program, 2012CB955904)the National Science Foundation for Young Scientists of China (41401510)
文摘Crop consumptive water use is recognized as a key element to understand regional water management performance. This study documents an attempt to apply a regional evapotranspiration model（SEBAL） and crop information for assessment of regional crop（summer maize and winter wheat） actual evapotranspiration（ET a） in Huang-Huai-Hai（3H） Plain, China. The average seasonal ET a of summer maize and winter wheat were 354.8 and 521.5 mm respectively in 3H Plain. A high-ET a belt of summer maize occurs in piedmont plain, while a low ET a area was found in the hill-irrigable land and dry land area. For winter wheat, a high-ET a area was located in the middle part of 3H Plain, including low plain-hydropenia irrigable land and dry land, hill-irrigable land and dry land, and basin-irrigable land and dry land. Spatial analysis demonstrated a linear relationship between crop ET a, normalized difference vegetation index（NDVI）, and the land surface temperature（LST）. A stronger relationship between ET a and NDVI was found in the metaphase and last phase than other crop growing phase, as indicated by higher correlation coefficient values. Additionally, higher correlation coefficients were detected between ET a and LST than that between ET a and NDVI, and this significant relationship ran through the entire crop growing season. ET a in the summer maize growing season showed a significant relationship with longitude, while ET a in the winter wheat growing season showed a significant relationship with latitude. The results of this study will serve as baseline information for water resources management of 3H Plain.
文摘This paper deliberates on the issue of water consumption (evapotranspiration, ET) of three main crops in North China: wheat, corn and bean, which is mainly related to three factors as indicated by the definition of SPAC system. Water consumption was measured on daily and sometimes hourly basis by Lysimeter, which can be adjusted to have the same groundwater level as that in the field, thus the measurement could serve as representative of crop water consumption for adjacent area. The consumption period for three crops has been analyzed and cumulative deviation from the mean of daily evapotranspiration been used to divide the whole growing period into several parts, which are related to but different from the growing periods. The serial correlation coefficients for varied lag time have been calculated to verify that the process of daily ET is not random, and therefore the cumulative daily consumption has been simulated by polynomial method, which gives relative good results. Finally, the effort has been made to investigate the relation of crop yield and water consumption and water use efficiency based on a time series of seven years.
文摘探索未来主要气候情景下参考作物蒸散量（reference evapotranspiration,ET0）的时空分布可为农业水资源科学配置,科学应对气候变化对农业生产的影响提供基础数据支撑。该文利用黄淮海及周围88个站点1961-2010年逐日气象数据,Penman-Monteith公式估算的ET0为因变量,采用非线性回归分析方法对Hargreaves公式进行参数属地化订正,基于1961-2005年温度日序列,利用统计降尺度模型（statistical downscaling model,SDSM）以及大气环流模型（general circulation models,GCMs）中加拿大地球系统模式（the second generation of Canadian Earth System Model,Can ESM2）得到代表性浓度（representative concentration pathways,RCPs）4.5和8.5两种排放情景下2010-2100年温度日序列,通过率定的Hargreaves公式预测黄淮海地区ET0,并采用普通克里格（ordinary Kriging）方法进行空间化处理。结果表明：率定后的Hargreaves公式与Penman-Monteith公式的相关指数波动范围为0.65-0.85,平均值为0.80,SDSM模拟的最低温度、最高温度率定期和验证期的确定性系数都在0.95以上;未来两种气候情景下,黄淮海地区ET0整体上均呈增加趋势;RCP4.5情景下ET0从河北与山东、河南交界处形成的＂勺＂状向周围逐渐减小,在河北唐山与乐亭、江苏东台、河南驻马店附近达到最小值;RCP8.5情景下黄淮海地区2020 s（2011-2040年）、2050 s（2041-2070年）ET0的空间分布和RCP4.5非常相似,但2080 s（2071-2100年）ET0的空间分布差异较大,最高值主要分布在山东惠民县附近、河南新乡附近、安徽蚌阜和江苏盱眙附近。如不采取科学的应对措施,未来ET0的增加,可能会进一步加剧该区水资源短缺程度,该研究可为黄淮海地区水资源的优化管理和灌溉制度制定提供科学参考。
