气候变化条件下宝鸡峡灌区主要作物需水量时空演变及节水潜力分析

发布时间：2018-01-26 08:07

  本文关键词： 宝鸡峡灌区 作物需水量 灌溉需水量 气候变化　出处：《西北农林科技大学》2017年博士论文　论文类型：学位论文

【摘要】：受气候变化的影响,极端天气事件频次趋多,水资源安全遭受极大挑战,尤其是农业灌溉用水形势颇为严峻,直接威胁到粮食安全问题。宝鸡峡引渭灌区是陕西省最大的灌区,对陕西省的农业生产乃至整个国民经济和社会发展起到极其重要的作用与影响。本研究以宝鸡峡灌区为主要研究对象,综合考虑灌区的气候资料、主要作物资料及灌溉农业发展状况等因素对灌区农业需水的影响,研究灌区农业需水的影响因素和时空变化规律,为制定气候变化条件下的灌区农业发展规划、确定合理的作物灌溉定额和种植制度,以及为应对气候变化灌区应采取的应对措施等提供参考。通过本文的研究,主要取得以下结果:(1)由于气象因素变化具有随机性,且波动起伏较大,根据气象因素的时间序列资料,本文分别计算各气象因素的平均值,并消除随机因素的波动影响,以显示各气象因素的变化趋势,依据变化趋势进行分析预测。根据宝鸡峡引渭灌区12个气象站点的地理位置和气象资料,计算灌区1961~2010年间逐月、逐年主要作物生育期的平均气温、最高气温、最低气温、平温风速、平均相对湿度、日照时数及降水量。运用时间序列分析法,探讨各气象因素的时间演变规律。分析发现:宝鸡峡灌区的面平均气温、最高气温及最低气温50年内总体呈波动性上升趋势,且最高气温和最低气温从1985年以后,表现出明显稳定增温效应。灌区面平均降水量和标准化降水指数(SPI)在时间序列上虽呈现频繁的波动性,但降水量与SPI在时间序列上总体呈下降趋势,且近20年来灌区气象干旱程度越来越严重,发生的频率增多,导致灌区向暖干方向演变。灌区相对湿度、风速和日照时数长时间尺度上的周期性变化不明显。此外,Hurst指数分析和小波分析的结果也表明:灌区平均气温、最高气温、最低气温和相对湿度呈增加趋势,风速、日照时数、降水量和SPI呈下降趋势。综合分析不同研究方法的结果,本文认为:未来宝鸡峡灌区各气象因素在未来长时间尺度上,将向暖干化方向变化。(2)从时间尺度上分析计算了宝鸡峡灌区内各站点各种主要作物多年平均的年际和年内需水量变化趋势。分析结果表明:棉花是四种主要作物中需水量最大的作物,1961~2010年棉花的多年平均需水量达到626.34 mm/a,多年日平均需水量介于1.53~4.70 mm/d之间;油菜的需水量次之,为574.38 mm/a,多年日平均需水量介于0.84~3.00mm/d之间;夏玉米的需水量较小,为468.61 mm/a,多年日平均需水量介于3.20~5.03mm/d之间;冬小麦的需水量最小,为447.32 mm/a,多年日平均需水量介于0.89~3.08mm/d之间。同时,分析了灌区不同作物的生育期内不同水文频率对应的需水量的年内变化规律。从空间尺度上,对宝鸡峡灌区12个站点1960~2010年50年间不同作物逐年全生育期需水量进行了分析。咸阳站冬小麦需水量多年平均值最大,达539.32mm/a;兴平站冬小麦需水量多年平均值最小,为466.76mm/a。咸阳站夏玉米需水量多年平均值最大,达520.59mm/a;扶风站夏玉米需水量多年平均值最小,为461.09mm/a。咸阳站棉花需水量多年平均值最大,达694.85mm/a;兴平站的棉花需水量多年平均值最小,为617.60mm/a。咸阳站油菜需水量多年平均值最大,达610.05mm/a;兴平站油菜需水量多年平均值最小,为530.94mm/a。(3)考虑到灌区面尺度上的作物需水量分布具有空间变异性,本文通过灌区内各代表点的作物需水量资料来估计宝鸡峡灌区整个面尺度的需水量分布特征,通过空间插值方法获得25%、50%、75%三个水文年型的灌区各主要作物的需水量空间分布特征。宝鸡峡灌区四种作物(冬小麦、夏玉米、棉花和油菜)需水量的空间分布特征基本一致,总体主要呈现为:从西至东逐渐增加和局部减少,从北到南整体上呈现逐渐减少和局部略有增加的变化特征。其中在灌区内12个站点中,北部的乾县站、礼泉站和东部的咸阳站不同作物在不同水文年型的需水量均偏大,而灌区中南部的扶风站和兴平站的需水量则明显偏低。(4)以往有关气象要素对作物需水量的影响研究中,大多采用相关分析法,但实际上各气象要素之间也存在较大相关性,对分析结果造成一定的影响。为此本文采用通径分析法,逐一分析各气象因素对宝鸡峡灌区作物需水量的影响,以及揭示各气象因素对作物需水量影响的相对重要性,并分析影响作物需水量的限制性气象因子。结果表明:宝鸡峡灌区影响作物需水量的主要气象因子是风速、日照时数、相对湿度、最高气温和平均气温,其决策系数绝对值均在10%以上。最低气温对冬小麦需水量综合影响的决策系数为-5.42%,是主要限制性因素。最高气温对夏玉米需水量综合影响的决策系数为-10.99%,是主要限制性因素。最低气温对棉花需水量综合影响的决策系数为-4.53%,是主要限制性因素。最高气温对油菜需水量综合影响的决策系数为-14.35%,是主要限制性因素。(5)应用回归分析法,进一步逐一分析研究了各气象因素对宝鸡峡灌区灌溉需水量的影响。研究发现:在冬小麦生育期,日照时数,平均气温和最高气温与灌溉需水量之间呈正相关关系,相对湿度和降水量与灌溉需水量之间呈负相关关系。夏玉米生育期,平均气温、最高气温、日照时数与灌溉需水量之间呈正相关关系,相对湿度、降水量与灌溉需水量呈负相关关系,spi与夏玉米需水量也达到了极显著的相关性。平均气温、日照时数、相对湿度、最高气温、风速和降水量对棉花的需水量影响较大。平均气温、最高气温、日照时数与棉花需水量之间呈正相关关系,spi与棉花灌溉需水量呈极显著的负相关关系。平均气温、最高气温、日照时数与油菜灌溉需水量之间呈正相关关系,而相对湿度、降水量与油菜灌溉需水量呈负相关关系。(6)综合考虑宝鸡峡灌区主要作物种植结构特点、种植面积、自然和经济条件及作物需求等,本研究参照目前常用的计算公式,计算了不同气候条件下的宝鸡峡灌区的节水潜力,在丰水年,主要作物的节水潜力最大,冬小麦和夏玉米的节水潜力分别为78.93 mm和122.72 mm;在平水年,作物的节水潜力较丰水年小,冬小麦、夏玉米、棉花、油菜的节水潜力分别为40.96 mm、105.93 mm、125.01 mm和70.65 mm;在干旱年,冬小麦、夏玉米、油菜的节水潜力为0,棉花节水潜力为24.10 mm。总体来看,宝鸡峡灌区在丰水年有较大的节水潜力,节水潜力与年型和作物都有密切的关系。
[Abstract]:Affected by climate change, extreme weather events tended to increase, water resources security suffered great challenges, especially the agricultural irrigation water situation is quite grim, a direct threat to the food security problem. Baoji Gorge Irrigation District is the largest irrigation district in Shaanxi Province, the Shaanxi Province agricultural production and the national economic and social development to the role and influence of extremely important. Based on the case study of Baoji Gorge Irrigation District as the main research object, considering the irrigation data and climate data, the main crop irrigation agriculture development status and other factors on the impact of irrigation water requirement, variation and temporal effects of irrigation water, irrigation and agricultural development planning and development for climate under the change, determine a reasonable crop irrigation quota and cropping system, and provide a reference should be taken to cope with climate change in measures through this research. The main results are as follows: (1) due to the randomness of the changes of meteorological factors, and fluctuations, according to the time series data of meteorological factors, calculate the average value of the various meteorological factors respectively, and to eliminate the fluctuation of the influence of random factors, in order to show the change trend of the meteorological factors, based on the trend analysis and forecast according to the Baoji Gorge Irrigation District of 12 meteorological stations in the geographical location and meteorological data, calculate the irrigation area during 1961~2010 month, average temperature, yearly growth period of main crops of the highest temperature, the lowest temperature, horizontal temperature wind speed, average relative humidity, sunshine hours and precipitation. By using the time series analysis method, to explore the various meteorological factors the time evolution law. Analysis shows that the average temperature of Baoji Gorge Irrigation District, the highest temperature and the lowest temperature in 50 years showed an overall upward trend in volatility, and the highest and lowest temperature from 198 5 years later, showed stable warming effect. Precipitation index average precipitation and irrigation standard (SPI) in the time series has fluctuated frequently, but the precipitation and SPI time series in the overall downward trend, and nearly 20 years irrigation meteorological drought degree is more and more serious. The frequency of occurrence increased, resulting in irrigation evolution to warm dry direction. Irrigation area, relative humidity, wind and sunshine when the periodic change number on a long time scale is not obvious. In addition, Hurst index analysis and wavelet analysis results also show that: Irrigation average temperature, maximum temperature, minimum temperature and relative humidity increased, the wind speed, sunshine hours, precipitation and SPI decreased. The results of a comprehensive analysis of different research methods, this paper think: the future of Baoji Gorge Irrigation District of various meteorological factors in the future on a long time scale, the direction of change to warm and dry. (2) from the time scale Analysis and calculation of the Baoji Gorge Irrigation District within the site main crop years average annual water volume change and domestic demand trends. Analysis results show that the water requirement of cotton is the largest crop of four main crops, cotton 1961~2010 multi-year average water demand reached 626.34 mm/a, between the daily average water requirement is 1.53~4.70 mm/d; rape the water requirement of 574.38 years between mm/a, daily average water demand is 0.84~3.00mm/d; low water consuming of summer maize, 468.61 mm/a, between the years of daily average water demand is 3.20~5.03mm/d; winter wheat water requirement minimum is 447.32 mm/a, between the years of daily average water demand is 0.89~3.08mm/d. At the same time, analyzed the change law of water required for irrigation period corresponding to different crops in different hydrologic years. From the spatial scale, the Baoji Gorge Irrigation District 12 site 1960~ between 2010 and 50 Water of different crops in the whole growth period for year by year were analyzed. The winter wheat water requirement for maximum average value of the XianYang Railway Station, XinPing Railway Station reached 539.32mm/a; winter wheat water requirement over the average minimum, 466.76mm/a. XianYang Railway Station for Summer Corn over the average maximum, up to 520.59mm/a; the Fufeng station for Summer Corn over the average minimum, 461.09mm/a. XianYang Railway Station the average water demand of cotton was the largest, up to 694.85mm/a; the XinPing Railway Station cotton water requirement for many years the average minimum 617.60mm/a. years average rape water requirement of XianYang Railway Station, XinPing Railway Station reached 610.05mm/a; rape water requirement for many years the average minimum, 530.94mm/a. (3) taking into account the scale on the surface irrigation water requirement of crop distribution has spatial variability in this paper, the representative points in the irrigation area of crop water demand data to estimate the water distribution characteristics of Baoji Gorge Irrigation District of the scale, 25%, through the 50% spatial interpolation methods, the spatial distribution characteristics of water demand of the main crops irrigation area of 75% three hydrological years. The Baoji Gorge Irrigation District Four Crops (winter wheat, maize, cotton and rapeseed) water spatial distribution is consistent, overall are: increased gradually from west to East. And reduce the local variation from north to south, showing the overall decreased and increased slightly. The local irrigation area in 12 sites in the north of the Qianxian County station, XianYang Railway Station and Liquan station of different crops in the eastern part of the water demand in different hydrological years are relatively large, and the water requirement of irrigated area of Fufeng south station and the XinPing Railway Station is obviously lower. (4) the effects of meteorological factors on crop water requirement, mostly by correlation analysis method, but there are also great correlation between the meteorological factors of actually, analysis the result of certain. Ring. This paper uses path analysis method, analyzes the influence of meteorological factors on the Baoji Gorge Irrigation District, crop water requirement, and reveal the relative importance of meteorological factors on crop water impact, and to analyze the impact of meteorological factors limiting crop water requirement. The results showed that the main meteorological factors affecting crop water requirement of Baoji Gorge Irrigation District is the wind speed, relative humidity, sunshine hours, maximum temperature and average temperature, the decision coefficient absolute value was above 10%. The minimum temperature of decision coefficient comprehensive effect of winter wheat water requirement is -5.42%, is the main limiting factor. The highest temperature of decision coefficient for summer maize comprehensive effects of water is -10.99%. Is the main limiting factor. The minimum temperature of decision coefficient of cotton needs comprehensive effects of water is -4.53%, is the main limiting factor. The highest temperature to the effect of water content on rape comprehensive decision coefficient -14.35%, is the main limiting factor. (5) analysis using regression analysis, further study the influence of meteorological factors on irrigation water demand of Baoji Gorge Irrigation District. The study found: in the growth period of winter wheat, sunshine hours, average temperature and maximum temperature and irrigation water amount was positively related to relationship between a a negative correlation between relative humidity and precipitation and irrigation water demand. During the growth period of summer maize, average temperature, maximum temperature, sunshine hours and irrigation water were positively correlated, between relative humidity, precipitation and irrigation was negatively correlated with SPI content of summer maize water demand has reached a significant correlation. The average temperature, sunshine duration, relative humidity, maximum temperature, water requirement of wind speed and precipitation of cotton is larger. The average temperature, maximum temperature, sunshine hours and cotton showed positive correlation between the content of SPI, and cotton Irrigation is a significant negative correlation between water. The average temperature, maximum temperature, sunshine hours and rape irrigation was positively related to the relationship between water, and relative humidity, precipitation and irrigation of rape is negatively related to water. (6) considering the main crops in Baoji Gorge Irrigation District planting structure, planting area, natural and economic conditions and crop demand, this study refers to the present commonly used formula, the water-saving potential under different climatic conditions of Baoji Gorge Irrigation District was calculated in wet year, the largest water saving potential of main crops, the water saving potential of winter wheat and summer maize were 78.93 mm and 122.72 mm; the water level. The water saving potential of crops is a wet year, winter wheat, maize, cotton, rape water-saving potential was 40.96 mm, 105.93 mm, 125.01 mm and 70.65 mm; in drought years, winter wheat, maize, rape water-saving potential is 0 cotton As a whole, the water saving potential is 24.10 mm., and the irrigation area in Baoji gorge has great water saving potential in the year of abundant water. The potential of water saving is closely related to the annual type and crop.

【学位授予单位】：西北农林科技大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：S274;S311
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本文编号：1465130