【作者】 王艳；

【导师】 李发文；

【作者基本信息】 天津大学 ， 水利工程， 2018， 硕士

【摘要】 由于华北地区地表水资源短缺,地下水长期处于超采状态,导致华北地区多处出现地下水漏斗区,使作物根系与地下水之间的水力联系减弱。加之,区域气候变化,导致气温持续上升,对当地农业发展造成了极大负面影响。为了充分利用当地农业自然资源,优化农艺措施,实现华北农业稳产高产的可持续发展,有必要分析和评价华北区域地下水及农业气候资源对农作物的影响,并对作物灌溉制度进行优化。本文选取海河流域石津灌区夏玉米为研究对象,主要围绕灌区现状条件下的水循环特征、地下水和未来气候对夏玉米生长的影响以及夏玉米灌溉制度优化四个方面进行研究,论文主要研究工作和成果如下:（1）根据石津灌区水循环的二元综合模式,分析该灌区各项通量及变化特征。石津灌区多年平均灌溉水和降雨总入渗补给不足以满足地下水的总消耗,导致地下水埋深呈现逐年下降趋势,农业用水竞争和水库来水变化导致灌溉用水总量有所降低,垂向蒸散发缓慢增加。（2）基于构建的AquaCrop模型,评价地下水埋深对夏玉米生长的影响。结果表明:石津灌区种植条件下,玉米的适宜地下水埋深是1.5².0m,最优地下水埋深为1.5m,当地下水埋深超过3.5m,可认为地下水对作物生长不产生影响。（3）利用区域气候模式HadGEM3-RA输出的气候情景RCP4.5和AquaCrop作物模型结合,定量分析气候变化对夏玉米产量的影响。结果表明:在RCP4.5情景下,石津灌区夏玉米未来产量主要以减产为主,但减产量变化呈现趋缓趋势,当不考虑CO₂直接影响时,产量变化幅度为–6.72%^–3.04%,当考虑CO₂直接影响时,产量变化幅度为–4.04%⁺0.11%。（4）以单方耗水净效益最大为目标,优化夏玉米灌溉制度。结果表明:在丰水年,可以不用进行灌水处理;在平水年,夏玉米可选择在苗期和拔节期分别灌一水,灌水定额为25mm,灌水总量为50mm,夏玉米产量达到了最大值7.23t/hm²,水分利用率为2.250 kg/m³;在枯水年,夏玉米可以选择在苗期,拔节期和开花期分别灌一水,灌水定额为46.6mm,灌水总量为140mm,夏玉米产量达到了最大值7.198 t/hm²,水分利用效率为1.992 kg/m³。更多还原

【Abstract】 Affected by human factors and environmental factors,groundwater funnels appeared in many places in north China,and the temperature continued to rise,which has a negative impact on local agricultural development.To make full use of local natural resources,optimize agronomic measures,and achieve sustainable development of high yield in north China,it is necessary to analyze and evaluate the impact of groundwater and climate resources on crops,and further optimize crop irrigation systems.In this paper,a main economic crop in the Shijin Irrigation District–summer maize was selected as the research object.The main research achievements were depicted as follows:（1）The fluxes and variations of this area were analyzed according to the bivariate comprehensive model of water cycle in Shijin Irrigation District.It can be seen that the average irrigation water and rainfall infiltration replenishment in Shijin Irrigation District is insufficient to meet the total consumption of groundwater,resulting in a downward trend of groundwater depth.Agricultural water competition and changes in reservoir inflow lead to a decrease in irrigation water consumption,and the vertical evapotranspiration increases slowly.（2）Based on the AquaCrop model,the effects of groundwater depth on summer maize growth were evaluated.The results showed that the suitable groundwater depth of summer maize in Shijin Irrigation District was 1.5-2.0m,the optimal groundwater depth was 1.5m,and its affection can be negligible when the depth exceeded 3.5m.（3）The effects of climate change on summer maize yield were quantitatively analyzed by combining the climate scenario RCP4.5 and AquaCrop model.The results showed that under the RCP4.5 scenario,the future yield of summer maize in Shijin Irrigation District was mainly reduced,but the yield change showed an upward trend.When the direct impact of CO₂ is not considered,the yield change ranged from–6.72%^–3.04%,when considering the direct impact of CO₂,the yield change ranged from–4.04%⁺0.11%.（4）The irrigation schedule of summer maize is optimized with the aim of maximum net profit of single water.The results showed that in wet year,the irrigation water was not needed.In normal year,summer maize can be irrigated at seedling and jointing stage respectively with an irrigation quota of 25mm,the total amount irrigation is 50mm,and the summer maize yield reaches a maximum value of7.23t/hm²,the water use efficiency is 2.250kg/m³.In dry year,summer maize can be irrigated at seedling,jointing and flowering stage respectively with an irrigation quota of 46.6mm,the total amount irrigation is 140mm,and the summer maize yield reaches a maximum value of 7.198t/hm²,the water use efficiency is 1.992kg/m³.更多还原