用^(137)Cs示踪法研究密云水库周边土壤侵蚀与氮磷流失  

Soil erosion and losses of nitrogen and phosphorus by using ^(137)Cs tracer in the areas around Miyun reservoir

作　　者：华珞[1] 张志刚[1] 冯琰[1] 赵红[1] 李俊波[1] 王向荣[1] 朱凤云[1] 

机构地区：[1]首都师范大学资源环境与地理信息系北京市重点实验室,北京100037

出　　处：《农业工程学报》2006年第1期73-78,共6页Transactions of the Chinese Society of Agricultural Engineering

基　　金：北京市自然科学基金(6012004);北京市教委项目(KM200510028014)

摘　　要：运用137C s核素示踪技术,研究密云水库周边地区及白河上游地区土壤侵蚀与氮、磷流失状况及其相互之间的量变关系。研究结果表明:从土壤表层(0~20 cm)137C s分布规律基本符合地形地貌的变化规律,山坡上部的137C s含量低于山坡中部与坡下部,但是如果山顶具有缓坡或山角下具有陡坡,则137C s含量变化规律相反。根据土壤137C s监测数据结果判定该地区基本属于轻度侵蚀和中度侵蚀,部分地区侵蚀情况达到剧烈程度。不同景观与土地利用方式对土壤氮、磷分布有巨大影响:有机质、全氮、水解氮含量均是以灌丛土壤最高,林地次之,与流域内137C s分布规律相符合;而农田中全磷、速效磷含量最高。不同区域土壤养分含量不同:水库上游地区土壤氮素、磷素含量均低于水库周边地区。证明不合理的人为活动严重的增强了土壤侵蚀程度与养分流失量。回归模拟了土壤中137C s、(210Pb)与全氮、全磷、水解氮、速效磷含量之间的数学模型。这些模型在区域较小、景观单一的范围内可以定量分析、预报预测各采样区的全磷和有效态氮、磷含量的变化趋势。简化了监测与分析测试程序。扩大了核素示踪技术的应用范围。Soil erosion,losses of N and P and the relations between them in Miyun reservoir heighborhood were researched by using ^137Cs tracer. The results showed that： the distribution of ^137Cs in the surface soils （0-20 cm） basically accorded with the changes of topography and physiognomy. The contents of ^137Cs on the top of hillside werelower than those in the middle and low hillside. But the distribution of ^137Cs contents was contrary on a flat slope in the mountaintop or on a sharp slope in the lowland. Based on the data of the researches, it proved that the region belongs to the slight and medium degree of erosion mainly, but erosion in some regions＇ conditions was serious. Different landscapes and land use patterns affected the distributions of N and P in soil greatly. The contents of the organic matter, total N, hydrolyze＇d N were higher in the soil than those under bush. These indications in the woodland took the second place, which accorded with the distribution of ^137Cs, contents in the region. The contents of total and available P in the farmland were the highest in soil under different land utilizations, which proved that the irrational humanity activities increased the soil erosion degree and losses of N and P seriously. The N and P contents in the upper reaches of reservoir areas, were lower than those in the reservoir neighborhood wholly. The mathematic models were simulated among ^137Cs （^210Pb） contents and the total N, total P, hydrolyzed N, available P of each sampling region respectively, which were described by cubic curve. The mathematic model can predict and forecast the change trends of the total P, available N and contents of P in each sampling region, simplify procedures of chemical analysis and extend application of nuclear tracer technique.

关 键 词：密云水库 ^137CS 土壤侵蚀 氮 磷 

分 类 号：S157.1[农业科学—土壤学]