發(fā)布時間：2018-04-14 13:17

  本文選題：蒸發(fā)蒸騰量 + 耗水特性��； 參考：《中國農業(yè)大學》2016年博士論文

【摘要】：理解農田土壤-作物系統(tǒng)水分傳輸機制以及選取適當方法對農田蒸發(fā)蒸騰量(E7)進行估算,是國際水科學研究的前沿和熱點問題。針對我國西北旱區(qū)水資源極度短缺的現(xiàn)狀,本文選取西北旱區(qū)制種玉米為研究對象,于2012-2014年以渦度相關系統(tǒng)、莖流計、自動氣象站和土壤水分監(jiān)測系統(tǒng)為基礎開展田間水分傳輸綜合觀測,探索了制種玉米父本母本耗水特性,建立了ET及其組分的估算模型。取得了如下主要成果：(1)揭示了制種玉米父本和母本在各生育期內植株形態(tài)及生理特性的差異性,探討了父本母本液流變化的差異及影響因子。試驗期間,母本液流速率明顯高于父本,2013和2014年最大差別分別為0.33和0.28 L d-1。小時尺度的父本母本液流速率主要受凈輻射、光合蒸騰速率及氣孔導度影響,日尺度液流速率與凈輻射、土壤含水量和葉面積指數(shù)密切有關,與株高相關性不顯著。父本日尺度的液流速率還與莖粗線性相關。(2)明確了制種玉米尺度轉換因子,探討了制種玉米ET變化規(guī)律和特征。采用葉面積、莖粗和密度為尺度轉換因子對單株液流進行尺度提升,與渦度相關實測的日尺度ET (ETEC)相比,以莖粗和密度為尺度轉換因子得到的日尺度ET在兩年試驗階段均明顯高于ETEC。采用葉面積為尺度轉換因子得到的ET在所測階段與ETEC有較好的一致性。全生育期內三年的ET分別為479.75、373.92和401.30mm；總的蒸騰量(Ts)分別為424.75、315.54和321.95mm,母本的蒸騰量明顯高于父本的蒸騰量,且母本蒸騰量占Ts的比例達63-80%；總的土壤蒸發(fā)(E)分別為55.00、47.77和62.21mm,E占ET的比例分別為11%、13%和16%。制種玉米的作物系數(shù)(Kc)在整個生育期內呈現(xiàn)出單峰曲線,三年全生育期平均Kc分別為0.78、0.79和0.73。(3)分析了不同冠層覆蓋度下制種玉米ET及Kc的變化規(guī)律,構建不同冠層覆蓋度下蒸發(fā)蒸騰量估算模型。在種植密度范圍內,全生育期的ET及Kc隨密度的增加而增加,而E隨密度的增加而減小。為了估算不同種植密度下的ET,引入密度比(K-density)修正了作物系數(shù)法,K-density為LAI的函數(shù)(K-density方法)。與考慮調整系數(shù)(Acm)的Allen方法、引入密度系數(shù)(Kd)的單作物系數(shù)(Kcm方法)和雙作物系數(shù)法(Kcb方法)相比,Kdensity方法在全生育期均與實測值較為接近。(4)提出了考慮冠層覆蓋度(f)變化及父本母本差異的冠層阻力組合方法,構建了基于有效阻力的P-M模型。與實測的有效表面阻力(rcec)相比,在f=1時,采用并聯(lián)的方法組合rcm和rcf得到的有效表面阻力與rcec有很好的一致性；當f1,rcm,rcf和rss采用以覆蓋度為權重因子的并聯(lián)方法組合得到的有效表面阻力兩年均明顯高于rcec。而采用基于LAI為權重因子的并聯(lián)方法與實測值較為一致。與最初的單層模型相比,基于兩種有效阻力計算方法的P-M模型的估算值更接近實測值,尤其是采用LAI為權重因子的考慮作物和土壤阻力并聯(lián)的組合方法。(5)分析了考慮父本母本混種及土壤多組分組合的作物系數(shù)法和基于相鄰作物光能截獲劃分模型的多源模型的應用效果,實現(xiàn)了制種玉米ET較精確的劃分。與作物系數(shù)法相比,采用多源模型模擬的ET、父本母本蒸騰值(乃及E兩年均與實測值較為一致,而作物系數(shù)法模擬的ET,父本母本T及E均高于實測值。
[Abstract]:To understand the soil crop system of water transport mechanism and selects the appropriate method for the farmland evapotranspiration (E7) estimation is the frontier and hot issues of international water science. According to the present situation of severe shortage of water resources in northwest arid region of our country, this paper selected for Maize in northwest arid region as the research object, in 2012-2014 years by the vorticity the related system, stem flow gauge, automatic weather station and soil moisture monitoring system based on field water transmission comprehensive observation, explore the maize seed parents water consumption characteristics, set up a model to estimate the ET and its components. The main results are as follows: (1) revealed the differences between the male and female seed corn in different growth during the period of morphological and physiological characteristics, discusses the difference of paternal parent flow and influence factors. During the test, each parent was significantly higher than that of liquid flow rate, and the maximum difference in 2014 2013 Don't were mainly affected by the net radiation parents liquid 0.33 and 0.28 L d-1. hour scale flow rate, photosynthetic rate and stomatal conductance influence on scale sap flow rate and net radiation, closely related to soil moisture and leaf area index, and were not significant. The high correlation between the liquid flow rate on the scale of the male parent with stem diameter correlation. (2) the corn seed production scale conversion factor of maize seed ET variation and characteristics. The leaf area, stem diameter and density scaling factor scale to enhance plant sap flow, and ET scale eddy correlation measurement (ETEC) compared with stem the coarse and density on scale ET scale conversion factor obtained in two trials were significantly higher than that of ETEC. by leaf area scale conversion factor obtained by ET are consistent in the test stage and ETEC ET for three years. During the whole growth period were 479.75,37 3.92 and 401.30mm; the total evapotranspiration (Ts) were 424.75315.54 and 321.95mm, transpiration transpiration was significantly higher than that of female male and female, transpiration accounted for the proportion of Ts was 63-80%; the total soil evaporation (E) were 55.00,47.77 and 62.21mm, E ET ratio was 11%, the 13% crop coefficient 16%. and corn (Kc) showed a single peak curve in the whole growth period, the average Kc three years in the whole growth period were 0.78,0.79 and 0.73. (3) analysis of the variation of different canopy coverage of maize ET and Kc, construct the estimation model of evapotranspiration of different canopy coverage in planting density. Within the range of ET and Kc in the whole growth period increased with the increase of density, while E decreases with the increase of density. In order to estimate the different densities of ET, the density ratio (K-density) modified crop coefficient method, K-density as a function of LAI (K-density). With the consideration of the adjustment coefficient (Acm) of the Allen method, introducing the density coefficient (Kd) of the single crop coefficient (Kcm) and dual crop coefficient method (Kcb method) compared to the Kdensity method in the whole growth period and the measured value is close to. (4) considering the canopy coverage (f) canopy resistance method of differentiation and paternal parent, P-M model is constructed based on the effective resistance. And the effective surface resistance test (RCEC) than in the f=1, the effective surface resistance and RCEC obtained by the method of combining RCM and RCF in parallel with good consistency; when F1, RCM, RCF and RSS by the effective surface resistance to get coverage as a combination of two parallel method of weight factors were significantly higher than that of rcec. and LAI based on parallel method for weighting factor accord with the measured values. Compared with the original single model, P-M model calculation method based on the two kinds of effective resistance The estimation values are close to the measured values, especially the use of LAI combination method considering crop and soil resistance parallel weight factor. (5) based on the analysis and application of multi-source model of the adjacent crop light interception partition model considering the crop coefficient of different combinations of male plants and soil mixed groups, which can realize the accurate corn seed ET. Compared with the crop coefficient method, the multi model simulation of ET, each parent value is E and transpiration (two years were similar, and the simulation of crop coefficient of ET, T and E male plants were higher than the measured value and the measured value.

【學位授予單位】：中國農業(yè)大學
【學位級別】：博士
【學位授予年份】：2016
【分類號】：S513
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本文編號：1749479