巢湖周边表土中有机质、全氮和全磷空间分布及其相关性

测定了巢湖周边3 528 km2范围内60个混合土样中的有机质(organic matter,OM)、全氮(total nitrogen,TN)和全磷(total phosphorus,TP)含量,通过GS 7.0+地统计学分析软件、Surfer 8.0及Mapinfo 8.5软件研究了这3种营养盐的空间分布,并使用SPSS 17.0软件对各指标间的相关性进行了分析.结果表明:①巢湖周边表土中ω(OM)、ω(TN)和ω(TP)平均值依次为19 500、1 027和483 mg.kg-1,东巢湖表土中ω(OM)和ω(TN)均值高于西巢湖,而磷矿的存在导致了ω(TP)均值西高东低;②位于巢湖西南的杭埠-丰乐河和白石天河周边表土中(TP)本底值较高,且水土流失十分严重,巢湖面源污染管理必须高度重视该两河的TP控制;③在线性模型下,巢湖周边表土中ω(OM)、ω(TN)和ω(TP)的块金值/基台值依次为0.015、0.202和0.128.巢湖周边表土中ω(OM)、ω(TN)和ω(TP)具有极强的空间自相关性,三者Pearson检验为两两显著相关,巢湖周边表土中ω(TN)和ω(TP)可由ω(OM)通过文中所得的公式估算,精度能满足日常管理需要.

Spatial Distribution Characteristics and Correlation Analysis of Organic Matter, Total Nitrogen and Total Phosphorus in Topsoil Around Chaohu Lake

Sixty topsoil composite samples(0-20 cm) have been collected in 3 258 km2 surrounding area of Chaohu Lake.The concentrations of organic material(OM),total nitrogen(TN) and total phosphorus(TP) were determined,and their spatial distribution characteristics were studied by geo-statistics software named GS 7.0+,Surfer 8.0 and Mapinfo 8.5.The correlations of these 3 kinds of nutrient were analyzed by SPSS 17.0 at the same time.Results showed that the average ω(OM),ω(TN) and ω(TP) in topsoil around Chaohu Lake were 19 500 mg·kg-1,1 027 mg·kg-1 and 483 mg·kg-1.The ω(OM) and ω(TN) in topsoil in the east of Chaohu Lake were both higher than those in the west of the lake,while ω(TP) was reverse.The ω(TP) in topsoil around Hangbu-Fengle River and Baishitianhe River which located in the southwest of Chaohu Lake was higher than that in any other rivers and with the serious soil erosion.Hence,to control the TP released by nonpoint pollution,attention should be paid on these two rivers.Furthermore,the semivariogram models of ω(OM),ω(TN) and ω(TP) followed linear model and they all had a strong spatial autocorrelation,the ratios of nugget to sill were 0.015,0.202 and 0.128,respectively.The characteristics of spatial distribution of ω(OM),ω(TN) and ω(TP) were similar.Moreover,the Pearson correlation analysis showed that ω(OM),ω(TN) and ω(TP) were significantly correlated.The ω(TN) and ω(TP) can be calculated by two recommended formulas,and the results were acceptable in daily non-pint pollution management.