基于^7Be示踪和细沟沟网分形维数研究坡面土壤侵蚀  

PLOT-SLOPE SOIL EROSION USING ^7Be MEASUREMENT AND RILL FRACTAL DIMENSION

作　　者：张风宝[1,2] 杨明义[2] 

机构地区：[1]清华大学水沙科学与水利水电工程国家重点实验室,北京100084 [2]西北农林科技大学中科院水利部水土保持研究所黄土高原土壤侵蚀与旱地农业国家重点实验室,陕西杨凌712100

出　　处：《核农学报》2010年第5期1032-1037,共6页Journal of Nuclear Agricultural Sciences

基　　金：国家“973”计划(2007CB407201);国家青年科学基金(40901127);博士后科学基金(20080440387);教育部新世纪优秀人才支持计划

摘　　要：本文试图结合7Be示踪和分形理论定量化描述降雨对坡面的侵蚀过程。7Be示踪结果显示,降雨初期,坡面细沟间侵蚀贡献率高,细沟侵蚀贡献率低,随着降雨的进行,细沟间侵蚀贡献率降低,而细沟侵蚀贡献率增大并处优势,在降雨后期,细沟间侵蚀贡献率又有增大的趋势。整个降雨过程坡面细沟沟网分形维数整体呈增大趋势,在细沟发育中前期增加快,后期增加变缓,中间有波动。细沟沟网分形维数与总侵蚀量和细沟侵蚀量均呈正相关,分维变与相对应总侵蚀量和细沟侵蚀量也均呈正相关,但与细沟侵蚀量的相关性最好,说明细沟沟网分形维数可表征细沟发育过程和坡面侵蚀强度的变化。In this study,we intended to use ^7Be measurement and fractal theory to quantify soil erosion process on slope.The results showed that contribution rate of interrill erosion was more than that of rill erosion during early stage of rainfall.When it rained,contribution rate of rill erosion began to be higher than interrill erosion and become the main part of erosion during medium stage of rainfall.The trend of contribution rate of interrill erosion was growing and the rill erosion was lowering during late stage of rainfall.Rill fractal dimension on the plot slope was almost growing larger during rainfall,growing quickly during early stage of rainfall and slowly during the late stage.Correlations was positive between rill fractal dimension and total erosion amount,also positive between rill fractal dimension and rill erosion.The correlations was positive between rill fractal dimension variation and total erosion amount,also was positive between rill fractal dimension variation and rill erosion amount.The best correlation was observed between rill fractal dimension and rill erosion amount.These results indicated that the rill fractal dimension on the plot slope could represent the development process of rill,the complex degree of rill and the variation of soil erosion intensity on the entire slope.

关 键 词：土壤侵蚀 ^7Be示踪 细沟分形维数 

分 类 号：S157[农业科学—土壤学]