宇宙射线快中子法在华北平原典型农田土壤水分测量中的应用  

Application of cosmic-ray fast neutron method in soil moisture measurement of typical farmland in North China Plain

作　　者：宋尚琨 田静[1] 何洪林[3] SONG Shang-kun;TIAN Jing;HE Hong-lin(Key Laboratory of Water Cycle and Related Land Surface Processes,Institute of Geographic Sciences and Natural Resources Research,Chinese Academy of Sciences,Beijing 100101,China;University of Chinese Academy of Sciences,Beijing 100049,China;Key Laboratory of Ecosystem Network Observation and Modeling,Institute of Geographic Sciences and Natural Resources Research,Chinese Academy of Sciences,Beijing 100101,China)

机构地区：[1]中国科学院地理科学与资源研究所陆地水循环及地表过程重点实验室,北京100101 [2]中国科学院大学,北京100049 [3]中国科学院地理科学与资源研究所生态网络观测与模拟院重点实验室,北京100101

出　　处：《应用生态学报》2019年第3期906-912,共7页Chinese Journal of Applied Ecology

基　　金：国家自然科学基金项目(41671354)资助~~

摘　　要：宇宙射线快中子法是一种新兴的能够实现区域土壤水分观测的方法.以中国科学院山东禹城综合试验站的宇宙射线连续观测数据和无线网络土壤水分观测数据为基础,研究了该方法在华北平原典型农田生态系统的适用性,重点探讨了采用标定法获得的土壤完全干燥条件下中子数(N_0)的稳定性和降雨灌溉对土壤水分估算的影响.结果表明:N_0的变化受下垫面变化影响,变化周期与试验区冬小麦和夏玉米的种植和收割期较一致.宇宙射线法估算的土壤水分对降雨和灌溉有明显响应,但在灌溉或降雨发生时会高估土壤水分.在华北农田生态系统条件下,宇宙射线法能有效地估算区域土壤水分,估算结果与浅层土壤水分观测值(10 cm深度)最为接近.Cosmic-ray neutron sensing (CRNS) is a new method for measuring mean soil moisture at regional scale. On the basis of continuous observation data of CRNS and the measurements of soil moisture with the distributed sensor network in Yucheng Comprehensive Experimental Station of the Chinese Academy of Sciences, we examined the applicability of the CRNS method to the agroecosystem in North China Plain. The stability of the neutron number in dry conditions (N0) and the effects of rainfall and irrigation on soil moisture estimation were investigated. The results showed that N0 was significantly affected by the underlying surface. The changes of N0 corresponded well to the planting and harvesting time of winter wheat and summer maize. Soil moisture estimated by the CRNS method had obvious response to rainfall and irrigation. When irrigation or rainfall occurred, soil moisture was overestimated. The CRNS method could effectively estimate regional soil moisture for the agroecosystem in North China Plain. The estimates of soil moisture were closest to the soil moisture in 10 cm depth.

关 键 词：宇宙射线快中子法 土壤水分 完全干燥条件 中子数 下垫面 

分 类 号：S152.7[农业科学—土壤学]