摘要
为研究人类活动对区域氮流的影响,以长江三角洲地区27个城市的统计数据为基础,采用物质流分析法建立氮流模型,分析长三角地区农业生产消费系统氮流特征,并采用情景分析法解析氮流驱动因素.结果表明,2011~2020年,长三角地区农业生产消费系统氮输入强度均值为194.6 kg·(hm^(2)·a)^(−1),是氮输入热点地区.化肥是最大的输入项.10年间,粮食和动物产品由净输出转为净输入.氮输出以氮环境损失为主,平均占比为53.2%.作物种植氮素利用效率和氮素循环利用率分别为38.7%~42.2%和15.8%~21.5%,均处于较低水平.系统氮输入和氮输出均呈现抛物线下降的趋势,分别降低11.3%和10.0%.空间上,氮输入强度总体呈现“北高南低”的格局,空间异质性显著.强度较高的城市主要分布在江苏北部及东部、上海和浙江东北部地区.各城市氮输入强度呈现显著的正向空间自相关性.基于情景分析法,畜禽养殖规模减少是氮输入降低最大的驱动因素.提高作物种植子系统氮素利用效率,重建作物种植和畜禽养殖之间的联系将有助于减少氮损失.
To assess the impact of human activities on regional nitrogen(N)flow,based on the statistical data of 27 cities in the Yangtze River Delta Region(YRD),N flow characteristics of the agricultural production and consumption system(APC)in the YRD from 2011 to 2020 were analyzed using substance flow analysis,and driving factors for N flow were analyzed using scenario analysis.The results showed that from 2011 to 2020,the mean N input intensity of the APC in the YRD was 194.6 kg·(hm^(2)·a)^(−1),which was more than five times the national average value;thus,the YRD was a hotspot of N input intensity in China.Chemical N fertilizer was the largest component of N input,and the YRD changed from a net export area of grain and animal products to a net import area due to the rapid growth of food consumption demand.The N output of the system was mainly N loss to the environment,accounting for 53.2%on average.The N use efficiency(NUE)of cropland and the N recycling ratio of the APC ranged from 38.7-42.2%and 15.8-21.5%,respectively,which were both at a low level.In addition,the total amount of N input and output of the APC both showed a parabolic decline trend,decreasing by 11.3%and 10.0%,respectively.Spatially,the overall N input intensity showed a pattern of“high in the north and low in the south,”and the spatial heterogeneity of N input intensity among cities was significant.Cities with high input intensity were mainly located in the north and east of Jiangsu,Shanghai,and northeast of Zhejiang.A significant positive spatial autocorrelation of the distribution of mean N input intensity was observed.The uncertainty of N flows was estimated using the error propagation equation.The uncertainty interval of N input and output ranged from 4.5%to 34.6%,which was roughly equivalent to the results of related studies,indicating that the model results were reliable.Based on the scenario analysis method,the decrease of the livestock scale led to a decrease of−0.27%-7.53%in the N input,making it the main reason for the decrease of
作者
张泽乾
董莉
刘鹏
周婷婷
孙丽慧
ZHANG Ze-qian;DONG Li;LIU Peng;ZHOU Ting-ting;SUN Li-hui(State Key Laboratory of Environmental Criteria and Risk Assessment,Chinese Research Academy of Environmental Sciences,Beijing 100012,China)
出处
《环境科学》
EI
CAS
CSCD
北大核心
2024年第9期5451-5463,共13页
Environmental Science
基金
中央级公益性科研院所基本科研业务费专项(2022YSKY-35)
国家环境保护河口与海岸带环境重点实验室开放基金项目(HKHA2022006)。
