Liu Er Hua, Zhou Guang Sheng
Chinese Academy of Meteorological Sciences, Beijing 100081, China.
Collaborative Innovation Center on Forecast Meteorological Disaster Warning and Assessment, Nanjing University of Information Science & Technology, Nanjing 210044, China.
Ying Yong Sheng Tai Xue Bao. 2019 Jan 20;30(1):233-242. doi: 10.13287/j.1001-9332.201901.039.
Crop water deficit status characterized by land surface-air temperature difference (T-T) has been widely investigated. However, empirical evidence for characteristics and impact factors of T-T considering the process of crop growth are less yet, which restricts the accurate simulation of T-T. Here, the data of T-T during the process of maize growth were obtained from five irrigation water control experiments after the period of summer maize 3-leaf stage in 2014 and jointing stage in 2015. The results showed that T-T of summer maize cropland was significantly affected by soil water content. T-T increased with the deficit of soil water. During summer maize water treatments, the normalized difference vegetation index (NDVI) was the main impact factor of T-T, with a significant linear relationship. However, during different growth stages, some additional factors including meteorological, biological and soil factors could also affect T-T, including canopy photosynthetic active radiation absorption ratio (f) after 3-leaf stage, relative soil water content (RSWC), and air relative humidity (RH) from 3-leaf stage to jointing stage. Then, the growth duration simulation model of T-T, vegetative growth simulation model of T-T and reproductive growth simulation model of T-T were established in terms of the data in 2014. Those simulation models were validated based on the experimental data of five irrigation water treatments after summer maize jointing stage in 2015. The results showed that the growth duration simulation mode of T-T could explain 63% variation of T-T in 2015. However, 79% variation of T-T could be explained by the simulation results of the vegetative growth simulation model of T-T and the reproductive growth simulation model of T-T. The results provided the basis for the quantitative evaluation of crop drought based on T-T.
利用地表-气温差（T-T）表征的作物水分亏缺状况已得到广泛研究。然而，考虑作物生长过程的T-T特征及影响因素的实证证据尚少，这限制了T-T的准确模拟。在此，通过2014年夏玉米三叶期和2015年拔节期后的5个灌溉水控制试验，获取了玉米生长过程中的T-T数据。结果表明，夏玉米田的T-T受土壤含水量显著影响。T-T随土壤水分亏缺而增大。在夏玉米水分处理期间，归一化植被指数（NDVI）是T-T的主要影响因素，二者呈显著线性关系。然而，在不同生长阶段，一些其他因素包括气象、生物和土壤因素也会影响T-T，其中包括三叶期后的冠层光合有效辐射吸收率（f）、三叶期至拔节期的相对土壤含水量（RSWC）和空气相对湿度（RH）。然后，基于2014年的数据建立了T-T的生育期模拟模型、营养生长模拟模型和生殖生长模拟模型。利用2015年夏玉米拔节期后5个灌溉水处理的试验数据对这些模拟模型进行了验证。结果表明，T-T的生育期模拟模型能解释2015年T-T变化的63%。然而，T-T的营养生长模拟模型和生殖生长模拟模型的模拟结果能解释T-T变化的79%。研究结果为基于T-T的作物干旱定量评估提供了依据。
