Using Path Analysis to Identify Impacting Factors of Evapotranspiration at Different Time Scales in Farmland

doi:10.3969/j.issn.1000-6362.2017.04.001

Abstract

Abstract:

Based on the data measured by large-scale weighing lysimeter and agricultural meteorological observation from 2011 to 2015, the distributing characteristics of evapotranspiration at different time scales in winter wheat farmland were analyzed, and the impacting factors were identified by path analysis. The results showed that the change of evapotranspiration displayed a downward-parabola pattern with a single peak at hourly scale, and the maximum evapotranspiration was from 0.9mm·h-1 to 1.1 mm·h-1 and the cumulative value throughout the day was from 7.0mm to 9.1mm on the typical sunny day during flowering-milky stage within 4 years. The mean annual evapotranspiration was 385.4mm, the mean diurnal evapotranspiration was 2.6mm·d-1 and the maximum value was 11.0mm·d-1 during the whole winter wheat growing period. The daily scale variation of evapotranspiration at early growing stage was greater than that at later stage. During the growing season, the evapotranspiration rate was lower during the sowing to turning-green period with an average of 1.1mm·d-1 than that of 4.2mm·d-1 after turning-green period. (2) The impacting factors of evapotranspiration at different time scales mainly included net radiation (Rn), saturated vapor pressure deficit (VPD), ground temperature (Tg0) and soil water content at 20cm (SW20). At hourly scale, VPD had the largest direct effect on evapotranspiration variation on the typical sunny day. Rn and Tg0 affected evapotranspiration indirectly via Rn. The ranking of the decision coefficient of every factor was VPD＞Tg0＞Rn. At daily scale, Rn, as the most critical factor, had the largest direct impact on evapotranspiration, while VPD had the largest indirect influence. VPD and Tg0 affected evapotranspiration indirectly via Rn and the indirect negative influence of SW20 was imposed by Tg0 path. The ranking of the decision coefficient of impacting factors was Rn＞VPD＞Tg0＞SW20.At the whole growing season scale, Tg0 and Rn were the only two most important factors with direct influence and could drive evapotranspiration change. The decision coefficient indicated that Tg0 could significantly increase the variation of evapotranspiration more than Rn.

Key words: Path analysis, Decision coefficient, Net radiation, Vapor pressure deficit, Crop evapotranspiration

ZHANG Xue-song, YAN Yi-lan, HU Zheng-hua. Using Path Analysis to Identify Impacting Factors of Evapotranspiration at Different Time Scales in Farmland[J]. Chinese Journal of Agrometeorology, 2017, 38(04): 201-210.

References

[1]谢贤群.我国北方地区农业生态系统水分运行及区域分异规律研究的内涵和研究进展[J].地球科学进展, 2003,18(3): 440-446. Xie X Q.Connotation and some advances of the research on the water movement and its regional change regular in agro-ecosystem of North China[J]. Advance in Earth Sciences,2003,18(3):440-446.(in Chinese) [2]Bradley R.1000 years of climate change[J].Science, 2000, 288(5470):1353-1355. [3]陈兆波,董文,霍治国,等.中国农业应对气候变化关键技术研究进展及发展方向[J].中国农业科学,2013,46(15): 3097-3104. Chen Z B,Dong W,Huo Z G,et al.Research advances and the development direction of key techniques for agriculture addressing climate change in China[J]. Scientia Agricultura Sinica,2013,46(15):3097-3104. (in Chinese) [4]任庆福,杨志勇,李传哲,等.变化环境下作物蒸散研究进展[J].地球科学进展,2013,28(11):1227-1238. Ren Q F,Yang Z Y,Li C Z,et al.Advances in the study of the crop evapotranspiration in changing environment[J]. Advances in Earth Science,2013, 28(11): 1227-1238.(in Chinese) [5]Clark G A,Smajstrla A G,Zazueta F S.Atmospheric parameters which affect evapotranspiration[M]. Florida:University of Florida,1989:1-6. [6] Mankin K R,Rogers D H.What is ET[M].Manhattan: Kansas State University,1998:1-2. [7]汪秀敏,申双和,韩晓梅,等.大型称重式蒸渗仪测定的冬小麦农田的蒸散规律研究[J].气象与环境科学,2011,34(4): 14-18. Wang X M,Shen S H,Han X M,et al.Study on evapotranspiration of the winter wheat measured by large-scale weighting lysimeter [J].Meteorological and Environmental Sciences,2011,34(4): 14-18.(in Chinese) [8]强小嫚,蔡焕杰,王健.波文比仪与蒸渗仪测定作物蒸发蒸腾量对比[J].农业工程学报,2009,25(2): 12-17. Qiang X M,Cai H J,Wang J.Comparative study of crop evapotranspiration measured by Bowen ratio and lysimeter[J]. Transactions of the CSAE,2009, 25(2):12-17.(in Chinese) [9]刘国水,刘钰,蔡甲冰,等.农田不同尺度蒸散量的尺度效应与气象因子的关系[J].水利学报,2011,42(3):284-289. Liu G S,Liu Y,Cai J B,et al.Study on scale effect of farmland evapotranspiration and relationship with meteorological factors[J].Shuili Xuebao,2011,42(3): 284-289.(in Chinese) [10]李菊,刘允芬,杨晓光,等.千烟洲人工林水汽通量特征及其与环境因子的关系[J].生态学报,2006, 26(8):2449-2456. Li J,Liu Y F,Yang X G,et al.Studies on water vapor flux characteristic and the relationship with environment factors over a planted coniferous forest in Qianyanzhou station[J]. Acta Ecologica Sinica,2006,26(8):2449-2456.(in Chinese) [11]王媛媛,张勃,尹海霞.1961-2010年陇东参考作物蒸散量时空变化及气候影响因子[J].生态学杂志,2013,32(6):1511-1517. Wang Y Y,Zhang B,Yin H X.Spatiotemporal variation of reference crop evapotranspiration and related climatic affecting factors in eastern Gansu of Northwest China in 1961-2010[J].Chinese Journal of Ecology,2013,32(6): 1511-1517.(in Chinese) [12]曹雯,段春锋,姚筠,等.1961-2010年安徽省参考作物蒸散时空变化特征及成因[J].应用生态学报,2014,25(12): 3619-3626. Cao W,Duan C F,Yao Y,et al.Temporal-spatial variations of reference evapotranspiration in Anhui Province and the quantification of the causes[J]. Chinese Journal of Applied Ecology,2014,25(12): 3619-3626.(in Chinese) [13]环海军,杨再强,刘岩,等.鲁中地区参考作物蒸散量时空变化特征及主要气象因子的贡献分析[J].中国农业气象, 2015,36(6):692-698. Huan H J,Yang Z Q,Liu Y,et al.Temporal and spatial variation of reference crop evapotranspiration and contribution of main factors in the middle area of Shandong Province[J].Chinese Journal of Agrome-teorology,2015,36(6):692-698.(in Chinese) [14]许杏娟,陈涛涛,吴奇,等.辽宁省凌河流域生长季参考作物腾发量变化及气候要素贡献分析[J].中国农业气象,2015, 36(1):33-42. Xu X J,Chen T T,Wu Q,et al.Analysis of the reference evapotranspiration change and climate factors contribution during growing season in Linghe basin of Liaoning Province[J].Chinese Journal of Agrometeorology,2015, 36(1):33-42.(in Chinese) [15]段春锋,缪启龙,曹雯.西北地区参考作物蒸散变化特征及其主要影响因素[J].农业工程学报,2011,27(8):77-83. Duan C F,Miao Q L,Cao W.Changing characteristics of reference crop evapotranspiration and main causes in the Northwest China[J]. Transactions of the CSAE,2011,27(8): 77-83.(in Chinese) [16]Kozak M,Kang M S.Note on modern path analysis in application to crop science[J].Communications in Biometry and Crop Science,2006,1(1):32-34. [17]张琪,丛鹏,彭励.通径分析在Excel和SPSS中的实现[J].农业网络信息,2007,(3):109-110. Zhang Q,Cong P,Peng L.The realization of path analysis in Excel and SPSS[J].Agriculture Network Information,2007, (3):109-110.(in Chinese) [18]贡璐,冉启洋,韩丽.塔里木河上游典型绿洲连作棉田土壤酶活性与其理化性质的相关性分析[J].水土保持通报, 2012,32(4):36-42. Gong L,Ran Q Y,Han L.Enzymatic activities and related physicochemical properties in soils of continuous cropping cotton fields within a typical oasis in upper reaches of Tarim River[J].Bulletin of Soil and Water conservation,2012, 32(4):36-42.(in Chinese) [19]张聪聪,陈效民,张勇,等.气象因子对太湖地区旱作农田土壤水分动态的影响[J].中国农业科学,2013,46(21): 4454-4463. Zhang C C,Chen X M,Zhang Y,et al.Influence of meteorological factors on soil moisture dynamics of upland soil in Taihu Lake region[J].Scientia Agricultura Sinica,2013, 46(21):4454-4463.(in Chinese) [20]Zhang F Y,Li L H,Ahmad S,et al. Using path analysis to identify the influence of climatic factors on spring peak flow dominated by snowmelt in an alpine watershed[J].Journal of Mountain Science,2014, 11(4):990-1000. [21]袁志发,周静芋,郭满才,等.决策系数:通径分析中的决策指标[J].西北农林科技大学学报(自然科学版),2001, 29(5): 131-133. Yuan Z F,Zhou J Y,Guo M C,et al.Decision coefficient: the decision index of path analysis[J]. Journal of Northwest A&F University (Natural Science Edition),2001,29(5): 131-133.(in Chinese) [22]刘春伟,曾勰婷,邱让建.用分时段修正双源模型估算南京地区冬小麦生育期蒸散量[J].农业工程学报,2016, 32 (Supp.1):80-87. Liu C W,Zeng X T,Qiu R J.Simulated total evapotranspiration of winter wheat with modified Shuttleworth-Wallace model in different stages in Nanjing[J].Transactions of the CSAE,2016, 32 (Supp.1):80-87.(in Chinese) [23]阳伏林,张强,王文玉,等.黄土高原春小麦农田蒸散及其影响因素[J].生态学报,2014,34(9):2323-2328. Yang F L,Zhang Q,Wang W Y,et al. Evapotran-spiration and factors influencing evapotranspiration in the spring wheat farmland of China's Loess Plateau[J]. Acta Ecologica Sinica, 2014,34(9):2323-2328.(in Chinese) [24]郭春明,任景全,张铁林,等.东北地区春玉米生长季农田蒸散量动态变化及其影响因子[J].中国农业气象,2016, 37(4):400-407. Guo C M,Ren J Q,Zhang T L,et al.Dynamic change of evapotranspiration and influenced factors in the spring maize field in Northeast China[J].Chinese Journal of Agrometeorology,2016,37(4):400-407. (in Chinese) [25]Roderick M L,Farquhar G D.The cause of decreased pan evaporation over the past 50 years[J]. Science,2002, 298(5597):1410-1411.