干旱区研究 ›› 2024, Vol. 41 ›› Issue (11): 1819-1830.doi: 10.13866/j.azr.2024.11.03 cstr: 32277.14.AZR.20241103

• 天气与气候 • 上一篇    下一篇

基于改进S-W模型的南小河沟流域蒸散发分配及控制机制

杨楠1(), 宋孝玉2(), 邓建伟1, 李蓝君2, 赵新凯2, 孟鹏飞2, 符冲2, 魏婉茵2, 张育斌1, 丁林1, 李浩霖3   

  1. 1.甘肃省水利科学研究院,甘肃 兰州 73000
    2.西安理工大学省部共建西北旱区生态水利国家重点实验室,陕西 西安 710048
    3.北京工业大学,北京 100124
  • 收稿日期:2024-05-12 修回日期:2024-06-26 出版日期:2024-11-15 发布日期:2024-11-29
  • 通讯作者: 宋孝玉. E-mail: songxy@xaut.edu.cn
  • 作者简介:杨楠(1997-),男,硕士研究生,主要从事水土保持、生态水文学研究. E-mail: 15379010323@163.com
  • 基金资助:
    甘肃省重点研发计划项目(22YF7FA081);陕西省自然科学基础研究计划项目(2023-JC-ZD-30);陕西省自然科学基础研究计划项目(2019JZ-45);甘肃省水利科研与技术推广计划项目(24GSLK007);甘肃省水利科研与技术推广计划项目(23GSLK012);甘肃省水利科研与技术推广计划项目(23GSLK013)

Research on the distribution and control mechanism of evapotranspiration in the Nanxiaohegou watershed based on an improved S-W model

YANG Nan1(), SONG Xiaoyu2(), DENG Jianwei1, LI Lanjun2, ZHAO Xinkai2, MENG Pengfei2, FU Chong2, WEI Wanyin2, ZHANG Yubin1, DING Lin1, LI Haolin3   

  1. 1. Gansu Academy for Water Conservancy, Lanzhou 73000, Gansu, China
    2. State Key Laboratory of Eco-Hydraulics in Northwest Arid Region of China, Xi’an University of Technology, Xi’an 710048, Shaanxi, China
    3. Beijing University of Technology, Beijing 100124, China
  • Received:2024-05-12 Revised:2024-06-26 Published:2024-11-15 Online:2024-11-29

摘要:

精准量化蒸散发(ET)及组分并探明其控制因子,有利于合理评价及规划管理区域水资源。根据黄土高原水土保持治理典型小流域南小河沟流域2016—2020年连续性长期观测数据及野外试验,基于改进的S-W(Shuttleworth-Wallace)模型,模拟典型人工林地ET及组分动态变化,并利用结构方程模型(Structural Equation Modeling,SEM)分析植物蒸腾(T)、土壤蒸发(E)与控制因子间的耦合关系。结果表明:(1) 改进的S-W模型在南小河沟流域适用性较好,其中土壤表面抗阻力( r s s)的阈值为50~2500 s·m-1,与土壤表层含水量(θ)经验函数类型为指数型,土壤颗粒中沙粒含量越大,线型斜率越大。(2) 典型人工林地ET范围为276.76~402.86 mm,多年平均TEET的51.6%和48.4%,ETTE规律为各月间变化不明显,但日间波动剧烈,TE波动趋势基本一致,与年降雨量变化一致,和次降雨表现滞后性。(3) SEM分析净辐射(Rn)、气温(Ta)、θET影响最为显著,其中RnT影响最大(总影响为0.614),TaE影响最大(总影响为0.426);TE体现为正相关,贡献系数达0.503。基于改进的S-W模型对ET进行评价及组分分离,为深刻揭示干旱半干旱区生态水文过程提供依据。

关键词: 蒸散发组分, 改进S-W模型, SEM模型, 蒸发抗阻力, 南小河沟流域

Abstract:

In this study, we aimed to accurately quantify evapotranspiration (ET) and its components while exploring the factors that control it, which will facilitate the practical evaluation, planning, and management of regional water resources. Utilizing continuous long-term observation data and field tests conducted from 2016 to 2020 in the Nanxiaohegou watershed—a typical small watershed for water and soil conservation on the Loess Plateau—this study simulated the dynamic changes of ET and its components in typical plantation land using the improved Shuttleworth-Wallace (S-W) model. Additionally, we analyzed the coupling relationships between plant transpiration (T), soil evaporation (E), and control factors using a structural equation model. The results revealed the following: (1) The modified S-W model was effective for evaluating ET and its components in Nanxiaohe Valley. The threshold value of soil surface resistance ( r s s) was 50-2500 s·m-1, exhibiting an exponential relationship with the empirical function of soil surface water content (θ); moreover, higher sand content in the soil particles correlated with a steeper linear slope. (2) ET ranged from 276.76 mm to 402.86 mm in typical plantation land, with annual averages of T and E accounting for 51.6% and 48.4% of ET, respectively. While monthly ET, T, and E patterns were not pronounced, daily fluctuations were significant. The fluctuation trends of T and E largely reflected annual precipitation patterns but lagged behind rainfall. (3) Structural equation modeling analysis revealed that net radiation (Rn), temperature (Ta), and θ exerted the most significant effects on ET, with Rn having the largest impact on T (total impact of 0.614) and Ta having the most significant impact on E (total impact of 0.426). T was positively correlated with E, with a contribution coefficient of 0.503. Evaluating ET and its components using an improved S-W model establishes a foundation for a deeper understanding of ecological and hydrological processes in arid and semiarid regions.

Key words: evaporative components, improve the S-W model, SEM model, evaporation resistance, Nanxiaohegou watershed