中文摘要：

珠江三角洲经济区是中国最富庶的地区之一,人类生产、生活活动对环境影响突出。在区域尺度,基于普遍性、区域性输入—输出因素通量模型,估算了不同土地利用方式下土壤重金属的年净通量,进而开展土壤重金属地球化学环境预测预警。预警主要通过由土壤重金属空间分布与其概率空间分布相结合的概率克里金法模型获得的因子污染概率进行。预警因子浓度阈值取自土壤环境质量国标标准二级标准。分析显示,研究区水田土壤的生态地球化学环境重警因素主要来自Cd,Hg,Ni,Cr,旱地土壤重警因素主要来自Cd,Hg,Ni,园地土壤重警因素主要来自As,Cr和Ni。如果不改变现在的发展方式,到2025年,水田土壤生态地球化学环境重警区域有江门市的蓬江区、江海区、新会区、开平市、鹤山市,整个中山市,广州的南沙区、番禺区,肇庆市的鼎湖区、端州区、高要市,以及珠海的斗门区。旱地重警区域主要为广州的番禺、南沙,白云区、黄埔区、罗岗区及花都区,佛山的高明、南海、顺德、禅城区,肇庆的四会,中山的小揽、古镇、三角、东升,珠海的斗门、金湾等,以及江门的市区、新会市、开平市和台山市。园地重警区域有广州的南沙、番禺区、花都区,惠州惠东县的北部等,珠海的斗门、金湾和坦洲,佛山的顺德区、南海区、禅城区、三水区等地。

英文摘要：

The Pearl River Delta Economic Zone（PRDEZ） is one of the most developed areas economically and socially in China,and its eco-geochemical environment is heavily affected by human activities.In this paper,net flux of soil heavy metals is estimated on regional input-output flux model,and then prediction and early-warning forecast on geochemical accumulation of soil heavy metals is carried out.Early warning forecast is conducted by the factor pollution index obtained from the Probability Kriging model which integrates the space distribution and probability distribution of soil heavy metals.The concentration threshold for warning factor is taken from the China National Environmental Quality Standards for the level-II soil.It is shown that Cd,Hg,Ni and Cr are the main eco-geochemical warning factors for the paddy land soil,Cd,Hg and Ni factors for the dry land,and As,Cr and Ni for the garden land.With the present development model going until the year of 2025,the heavily warning regions of paddy land soil will extend to the Pengjiang District,Jianghai District and Xinhui District in Jiangmen City,Kaiping,Heshang,Zhongshan,Nansha Districts,Panyu District in Guangzhou City,Dinghu District,Duanzhou District and Gaoyao District in Zhaoqing City,and Doumen District in Zhuhai City.The heavily warning regions of dry land soil will extend to Panyu District,Nansha District,Baiyun District,Huangpu District,Luogang District and Huadu District in Gangzhou City,Gaoming District,Nanhai District,Shunde District and Shancheng District in Foshan City,Sihui District in Zhaoqing City,Xiaolan District,Guzhen District,Sanjiao District and Dongshen District in Zhongshan City,Doumen District and Jinwandeng District in Zhuhai City,and Xinhui,Kaiping and Taishan in Jiangmen City.The heavily warning regions of garden land soil will extend to Nansha District,Panyu District and Huadu District in Guangzhou City,the northern Huidong County in Huizhou City,Doumen District,Jinwan District and Tanzhou District in Zhuhai City,and Shunde District,Na