利用γ射线透射法测量径流含沙量及算法

首次尝试采用γ射线透射法测量土壤侵蚀径流中的含沙量。用两种不同土壤(黄绵土、粘土)、三种含沙量增量(3%、5%、10%)和三种测量时间(6s、10s、20s)进行了含沙量测量实验,以验证用γ射线测量泥沙含量的可行性、确定泥沙含量对γ射线的响应特性。并推导了根据γ射线透射强度计算含沙量的理论计算公式。将实验结果与理论计算值进行对比,以检验理论计算的准确性和测量实验与理论计算的一致性。结果表明,γ射线透射通过泥沙溶液的强度与水流含沙量间有极度显著的线性相关关系,并与理论计算结果高度一致,表明可由γ射线透射强度稳定、可靠、准确地确定含沙量值

Determining Sediment Concentration in Runoff Flow with γ Ray Attenuation and the Related Theoretical Algorithm

An attempt was made to use gamma ray transmission method to measure sediment concentration in runoff. Two types of soils (silt loess and clay loess), three increments of sediment concentration (3%, 5% and 10%) and 3 sampling periods (6 s, 10 s, 20 s) were adopted for sediment measuring experiments, so as to validate the feasibilities of measuring sediment concentration with gamma ray method and to determine the response of measured sediment concentration to different conditions. The theoretical algorithm was derived for determining sediment concentration with gamma ray method. A simple relation of sediment concentration with gamma ray readings was statistically given. Experimental data were used to verify the correctness of the theoretical equation and to check the consistency of the theoretical results with those from experiments. Results showed very good linear relationship between sediment concentrations and gamma ray readings, as well as very good consistency between measured sediment concentrations and the theoretically computed values. The gamma ray method can be used to determine sediment concentrations steadily, reliablly and precisely.