干旱内陆区玉米农田水热传输多过程耦合机理与模拟

Cropland is probably the most active part of the terrestrial ecosystem and strongly affected by human activities. Deeply understanding coupling mechanism of multi-processes, and dynamically simulating the processes by establishing the quantitative model are one of the difficult and hot issues of the international research. In this study, the comprehensive observations of water and heat fluxes at different space-scales (leaf, individual and field) and time-scales (from minutes to many years) will be conducted using many instrumentations at seed maize field of an arid inland region. The transfer characteristics of water and heat fluxes at the different spatial-temporal scales, and their coupling mechanism with physiological and environmental processes will be revealed. The main processes controlling the transfers will be determined by using mathematical methods of partial differential and boundary line analysis. The key processes for scaling up water and heat fluxes will be recognized by introducing wavelet transform technology. Based on identifying multi-processes coupling mechanism, a multi-processes mechanistic model of water and heat transfer will be built, including the processes of canopy radiative transfer, energy balance in leaves, crop physiological regulation, meteorological turbulence transport, and soil water and heat transfer. The mechanistic model can be used to accurately simulate and predict water and heat fluxes. Based on the above mechanistic model, the application model will be established to estimate latent heat flux of seed maize, accounting for the canopy structural differences between male and female plants through the theoretical derivation. The scientific basis and guidance will be provided for completing water cycle theory in agriculture and improving efficiency of agricultural water management through this project.

农田是受人类活动影响最为强烈的一类陆地生态系统。深入认识农田水热传输多过程耦合机理并建立定量模型动态模拟是国际研究的难点和热点问题。本研究选取干旱内陆区制种玉米农田为研究对象，利用多种仪器设备开展不同空间（叶片、单株和农田）和时间尺度（分钟到多年）的水热通量综合观测，以揭示农田不同时空尺度水热通量的传输特征及其与生理和环境过程的耦合机理，并应用偏微分和边界线分析等数学方法确定主控过程。引入小波变换技术获得适于水热通量尺度转换的关键过程。在机理认识的基础上，构建耦合冠层辐射传输、叶片能量平衡、作物生理调控、气候湍流输送和土壤水热运移等多过程的农田水热传输机理模型，以实现水热通量的准确模拟和预报。在机理模型基础上，考虑制种玉米父本和母本植株冠层结构差异的特点，通过理论推导建立适合于估算制种玉米潜热通量的实用模型。通过本项目研究，为完善农业水循环理论和提高农业高效用水管理提供科学依据和指导。

农田是受人类活动影响最为强烈的一类陆地生态系统。深入认识农田水热传输多过程耦合机理并建立定量模型动态模拟是国际研究的难点和热点问题。本项目围绕深入认识农田水热传输多过程耦合机理并建立定量模型动态模拟的项目目标，选取干旱内陆区玉米为研究对象，利用多种仪器设备开展了不同时空尺度的水热通量综合观测，揭示了不同时空尺度水热通量的传输特征及其与生理和环境过程的耦合机理及对主控因子的响应关系，构建了耦合冠层辐射传输、叶片能量平衡、作物生理调控、气候湍流输送和土壤水热运移等多过程水热通量多层模型，建立了估算异质冠层结构的作物耗水模型。在试验研究与理论分析的基础上，依托本项目在水文学和农业水领域主流期刊《Journal of Hydrology》、《Hydrological Processes》、《Agricultural Water Management》和《水利学报》等共发表SCI、EI收录论文7篇，其中第一作者6篇、通讯作者1篇；ESI前10%的1篇，10-20%的3篇，SCI论文累积影响因子（2015年）为14.074；第1完成人获发明专利1件。2013年第1作者发表在《Agricultural and Forest Meteorology》(2015 IF: 4.461)的相关论文入选2012至2015年期间的ESI高被引论文。依托本项目2016年新申请国家自然科学基金面上项目1项。项目负责人在“Workshop on Water and Food Security under Changing Environments”等国内外学术会议作报告5次。依托本项目，负责人2015年晋升为副教授、2016年获大北农青年学者奖。研究成果给科学同行准确测定水热通量、识别水热传输主控因子和定量模拟提供了一些新见解，对农业水科学发展有一定促进作用。关于作物耗水估算的研究成果已应用到西北旱区石羊河流域灌溉制度科学制定和节水精量灌溉中，对流域的水资源合理配置和优化调度提供了科学依据。