快速城市化地区LUCC对重金属迁移的影响机制

Land use/cover can directly absorb or adsorb heavy metals, and also can control the mobility and activity of heavy metals in the soil by changing the soil physical, chemical and biological properties, resulting in the accumulation of heavy metals in the soil. Urbanization is usually associated with large-scale land use/cover change (LUCC), which has become an important driving force of regional environmental change. The influence of land cover types and their patterns on heavy metals based on the LUCC process has become a new study direction of soil heavy metal pollution. Xiaoqing River Basin of Jinan section，characterized as typical high intensity of human disturbance and rapid urbanization，is chosen as study area. The accumulation characteristics of heavy metals in various environmental media and spatial and temporal distribution are studied in the background of basin LUCC and landscape pattern. Heavy metals in the main source of and its input channels are also analyzed. Additionally, the relationship between basin LUCC and the heavy metal source information are explored. Furthermore, it is revealed the basin LUCC landscape succession and heavy metal cycle coupling relations as well as heavy metals in the basin of LUCC in the response mechanism. Using GIS technology, high spatial resolution basin model are to be built, to predict the behavior of heavy metals in the different areas of the basin system of soil media, providing a scientific basis for the protection of watershed ecology and health and safety.

土地利用/覆被可以直接吸纳或吸附重金属，亦能通过改变土壤物理、化学和生物性质从而控制重金属在土壤中的移动性和活性，造成土壤中重金属的积累直至污染。城市化所伴生的大规模土地利用/覆被变化（LUCC）已经成为区域环境变化的重要驱动力。基于LUCC过程的土地覆被类型及其格局对重金属污染的影响成为土壤重金属污染研究的一个新方向。项目选择高强度人类扰动和快速城市化的典型区小清河流域济南段为研究区域，研究流域LUCC及景观格局演变背景下，各环境介质中重金属的富集特征与时空分布规律，辨析重金属主要来源及其输入途径，探讨流域LUCC与重金属源信息的相互关系，揭示流域LUCC景观演替与重金属循环的耦合关系以及重金属对流域LUCC的响应机理，针对地表特征演变，基于GIS技术构建具有高空间分辨率的重金属流域迁移模型，预测流域系统不同区域不同地表各介质中重金属的迁移行为，为保护流域生态与健康安全提供科学依据。

摘 要：城市化所伴生的大规模土地利用/覆被变化（LUCC）已经成为区域环境变化的重要驱动力。本研究围绕LUCC以及土地利用变化引起的环境效应进行了系列研究，分别针对城市土壤重金属、城市地表热环境、大气气溶胶、城市大气细颗粒物污染进行了研究，取得的研究成果主要体现在以下几方面：揭示了LUCC引起的地表热环境变化特征、机制，并构建了热环境与地表参量的模型；分析了LUCC背景下，大气气溶胶光学厚度的演变特征，并阐述了典型城市的大气灰尘污染物传输与风险；阐释了LUCC背景下，土壤重金属的累积特征、空间分异与累积风险。本项目的研究成果，将对LUCC引起的地表-大气-土壤环境变化的反演与响应等研究具有重要的理论与实用价值。