南昌快速城市化过程对环境多介质有机碳含量的影响

Impacts of rapid urbanization on the content of organic carbon in multimedia of Nanchang

基于1983—2014年6期Landsat遥感影像并结合地统计学方法,分析了南昌市近30年来快速城市化对环境多介质(土壤、灰尘及沉积物)有机碳含量及空间分布的影响.结果表明:(1)南昌市近30年间城市化过程经历了3个阶段:一个高速增长阶段(2000—2005年)和两个低速增长阶段(1983—2000年、2005—2014年);(2)南昌市灰尘、土壤及沉积物中有机碳平均含量分别为28.71、25.21和14.90 g·kg^(-1),均远高于江西省土壤有机碳背景值(2.44 g·kg^(-1));(3)市区主干道路沿线表层土壤有机碳含量显著高于郊区土壤,其分布总体呈现出由市区向郊区阶梯式递减的规律;(4)老城区灰尘有机碳含量高于新建城区,大致随着城市扩张方向呈现逐渐减少的趋势,表现出显著的空间异质性;(5)湖相沉积物有机碳含量在水平方向上也大致呈现出由市区向郊区减小的趋势.

Based on 6 phase Landsat remote sensing images from 1983 to 2014, the effects of rapid urbanization on the content and spatial distribution of organic carbon in multimedia （soil, dust and sediment） in Nanchang were analyzed by geostatistical methods. The results showed that the process of urbanization in Nanchang city experienced three stages during the past 30 years, a rapid development stage （2000-2005） and two slow-development stages （1983-2000, 2005-2014）. The average content of organic carbon in dust, soil, and sediment were 28.71, 25.21 and 14.90 g·kg^-1, respectively, which were greatly higher than the background value of soil organic carbon in Jiangxi province （2.44 g·kg^-1）. Organic carbon content in topsoil along the main road in the downtown was significantly higher than that in the suburban and its distribution showed a stepwise decreasing from the downtown to the suburb. The content of organic carbon in dust presented highly spatial heterogeneity and significantly decreased from the old city to the new zone, regardless of seasons. The content of organic carbon in the lake sediment generally showed a clear decreasing trend from the downtown to the suburbs.