华北平原冬小麦生育期降水量、作物参考蒸散及干旱风险分析

发布时间：2018-03-06 15:05

本文选题：华北平原　切入点：冬小麦　出处：《中国气象科学研究院》2015年硕士论文　论文类型：学位论文

【摘要】：本文基于华北平原52个台站和322个台站气象数据与产量数据,分析了不同台站密度数据对冬小麦全生育期内的降水量、ET0及作物水分亏缺率时空变化特征的影响,并分析华北平原冬小麦生育期作物水分亏缺率的时空变化特征以及冬小麦干旱风险在华北平原的空间变化趋势。在分析冬小麦水分亏缺率时,假设了无底墒、土壤相对湿度分别为45%、55%、65%、75%、85%六种底墒条件,分析底墒对冬小麦作物水分亏缺率时空变化的影响,并在此基础上分析底墒对冬小麦干旱风险的影响。主要研究结果有:(1)采用52个台站气象资料在时间上可以获取和322个台站较为一致的冬小麦生育期水分变化特征,同时在大多数区域也可获得较为一致的空间分布特征,但在地形起伏较大的山前平原以及山脉周围区域。目前,利用基准台站所进行的各种华北冬小麦水分时空分布特征分析基本可靠,但实际农业生产决策时,所有华北山前平原及泰山附近区域的研究结果应当慎重对待、谨慎参考。(2)全华北平原冬小麦生育期内降水量在1961-2010年有增加趋势,且增加趋势较为明显。生长季内降水量的增加,可以有效降低冬小麦水分亏缺程度和干旱发生风险。(3)华北平原冬小麦生育期内ET0在1961-2010年间大部分区域有逐渐减少的趋势,只有平原东北部的河北东北部、北京、天津等地区、山东东北部、河南南部及西部的部分区域参考作物蒸散ET0有所增加。(4)华北平原冬小麦生育期作物水分亏缺率随时间的变化趋势不明显,空间上呈纬向分布,作物水分亏缺率随着纬度的增加而增大,且底墒明显降低了冬小麦的水分亏缺率,当土壤相对湿度达到75%以上时水分亏缺情况与底墒充足时的差异较小。(5)危险度呈纬向分布,随着纬度的增加而增加,且随着底墒的增加冬小麦干旱的危险性明显降低。当土壤相对湿度达到75%以上时,冬小麦干旱主要是由于生育期内水分异常偏少造成的,降低干旱的风险应在生育期内降水偏少的时段及时浇水;当土壤相对湿度为45%时,河北省大部分区域、京津地区、山东西北部危险度较高,由于底墒的不足可能造成大面积干旱。(6)底墒对冬小麦作物水分亏缺率以及干旱危险性的影响表明,土壤底墒是冬小麦生育期内不可忽略的水分来源,不考虑底墒会较大程度的夸大水分亏缺状况以及干旱的危险性,这将给干旱的预防工作带来不实的依据。
[Abstract]:Based on meteorological data and yield data of 52 stations and 322 stations in North China Plain, the effects of different station density data on the temporal and spatial variation characteristics of precipitation et 0 and crop water deficit rate during the whole growth period of winter wheat were analyzed. The temporal and spatial variation characteristics of crop water deficit rate in North China Plain and the spatial variation trend of winter wheat drought risk in North China Plain were analyzed. The soil relative humidity was 45 ~ 55 and 65%, respectively. The effect of soil moisture on the temporal and spatial variation of crop water deficit rate of winter wheat was analyzed. On this basis, the effects of soil moisture on drought risk of winter wheat were analyzed. The main results are: 1) using meteorological data of 52 stations can obtain the variation characteristics of water in winter wheat growing period in time consistent with 322 stations. At the same time, a more consistent spatial distribution can be obtained in most regions, but in the mountainous plains and surrounding mountain areas, where the terrain is quite undulating. The analysis of water temporal and spatial distribution of winter wheat in North China by using the reference station is basically reliable. However, in the actual agricultural production decision, all the research results of the North China Piedmont Plain and the area near Mount Tai should be treated with caution. The precipitation of winter wheat in the growth period of North China Plain increased in 1961-2010, and the increasing trend was obvious. It can effectively reduce the water deficit and drought risk of winter wheat.) during the growing period of winter wheat in North China Plain, the ET0 decreased gradually in most areas during 1961-2010, only in northeast Hebei, Beijing, Tianjin and so on. The evapotranspiration (ET0) of some reference crops in northeast Shandong, southern Henan and western Henan increased. 4) the crop water deficit rate in winter wheat growing period in North China Plain was not obvious change with time, but the spatial distribution was zonal. The water deficit rate of crops increased with the increase of latitude, and the water deficit rate of winter wheat was obviously reduced by soil moisture. When the soil relative humidity was above 75%, the difference between soil water deficit and soil moisture abundance was smaller. With the increase of latitude and the increase of soil moisture, the drought risk of winter wheat decreased obviously. When the relative humidity of soil reached more than 75%, the drought of winter wheat was mainly caused by the lack of water in the growth period. To reduce the risk of drought, water should be watered in time when the precipitation is relatively low during the growing period. When the soil relative humidity is 45%, the risk is higher in most regions of Hebei Province, Beijing and Tianjin areas, and northwest Shandong. The effects of soil moisture on the water deficit rate and drought risk of winter wheat crops indicated that the soil moisture content in the soil was a water source that could not be ignored during the growing period of winter wheat. Not considering the soil moisture will greatly exaggerate the situation of water deficit and the danger of drought, which will bring false basis to the prevention of drought.
【学位授予单位】：中国气象科学研究院
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S512.11;S423

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