论文部分内容阅读
在利用土壤侵蚀模型估算侵蚀速率的过程中,背景值点选取的好坏直接关系到结论是否可靠,如果能通过科学计算得出研究区域背景值,将大大提高背景值的准确性,对研究土壤侵蚀具有重大意义。土壤未受到侵蚀和沉积的背景区,首先假设全球大气沉降量为定值,研究把210Pbex沉降过程以一年为时间尺度划分为n年,经过n年以后(n=0,1,2,…,∞),土壤中210Pbex沉降量和经过衰变减少量达到平衡,土壤中210 Pbex含量趋于稳定。假设各地年平均降水量为定值,通过研究发现210Pbex的大气沉降通量与年降水量之间存在极显著相关(P<0.01),区域年降水量是影响土壤中210Pbex量的主要因素,由于年平均降水量不同,全球各地土壤中210 Pbex含量都会达到不同的稳定值,从而建立土壤中210Pbex含量与年降水量关系模型。研究210Pbex来源、沉降的连续性和稳定性,提出利用区域年平均降水量来计算该地区的210Pbex背景值,建立土壤中210Pbex背景值含量动态平衡模型,为准确确定210Pbex背景值提供了方法,对研究土壤侵蚀具有重要的意义。
In the process of using soil erosion model to estimate the erosion rate, the selection of the background value points is directly related to whether the conclusion is reliable. If the background value of the research area can be obtained through scientific calculation, the accuracy of the background value will be greatly improved, Erosion is of great significance. The background area of the soil that has not been eroded and deposited first assumes that the global atmospheric deposition is a fixed value. The 210Pbex sedimentation process is divided into n years on a year-by-year basis, and after n years (n = 0, 1, 2, ... , ∞). The amount of 210 Pbex sedimentation and the decrease of decay in soil reach equilibrium, and the content of 210 Pbex in soil tends to be stable. Assuming that the annual average precipitation is a fixed value in all regions, it is found that there is a significant correlation between 210Pbex precipitation and annual precipitation (P <0.01). The annual precipitation is the main factor affecting the amount of 210Pbex in soil. The annual average precipitation is different, so the 210 Pbex content in soils around the world will reach different stable values, so as to establish the relationship model between the 210Pbex content and the annual precipitation in the soil. The 210Pbex background value of 210Pbex background was calculated by using annual average precipitation of 210Pbex sources and the stability of 210Pbex source was proposed. The 210Pbex background content dynamic equilibrium model was set up to provide a method to accurately determine 210Pbex background value. Studying soil erosion is of great significance.