区域农业源碳—氮—磷排放的耦合协调度模型与应用

MODEL AND APPLICATION OF CARBON, NITROGEN, AND PHOSPHORUS EMISSIONS AND THEIR COUPLING FEATURES IN AGRICULTURAL SOURCES

关键词:  农业面源  氮磷流失  温室气体  耦合协调度  碳核算  减污降碳

Key words:  agricultural non-point sources  nitrogen and phosphorus loss  greenhouse gases  coupling coordination  carbon accounting  pollution reduction and carbon mitigation

摘要:

目的 人为活动导致的碳氮磷失衡排放是造成水环境恶化和气候变化的主要原因，农业源是区域温室气体排放和水体氮磷流失的重要来源，解析其排放与耦合特征是实现区域减污降碳协同调控的重要基础。方法 文章以广东省为研究区，构建了省级碳氮磷排放核算方法与耦合协调度模型，评估了全省农业源碳氮磷排放总量、结构、协同水平的多年时序变化特征及其影响因素。结果 （1）2000—2022年广东省农业源碳、氮、磷排放呈现阶段性特征和不同变化趋势，总体表现为碳排放下降、磷排放上升和氮排放波动的时间变化特征；（2）当前全省碳—氮—磷排放量处于“基本协调”等级，其中氮、磷与碳之间的耦合协调度较低，处于“轻度失调”等级，不同元素之间的耦合协调度均具有显著的跨等级年际变化特征；（3）广东省农业源碳氮磷排放虽然具有同源性，但影响因素对不同元素排放的驱动效应差异较大，导致农业源碳—氮—磷耦合协调度与农业农村活动因子的弱相关关系；（4）2000—2022年广东省农业源碳氮磷排放不确定性范围分别为±22%、±29%和±30%。结果 未来需进一步研究不同来源参数的不确定性，该研究结果为区域农业源减污降碳调控提供科学决策依据。

Abstract:

Human activities have led to an imbalance in carbon, nitrogen, and phosphorus emissions, which are the leading causes of water environment deterioration and climate change. Agricultural sources significantly influence regional greenhouse gas emissions and the runoff loss of nitrogen and phosphorus. Analyzing the emission and coupling characteristics of agricultural sources is essential for achieving coordinated pollution reduction and carbon mitigation at the regional level. In this study, we focused on Guangdong province and established a provincial-level accounting method for carbon, nitrogen, and phosphorus emissions, along with a coupling coordination model. Over multiple years, we assessed the temporal variations and influencing factors of the total emissions, structure, and coupling levels of carbon, nitrogen, and phosphorus emissions from agriculture in the province. The results indicated that: (1) From 2000 to 2022, carbon and nitrogen emissions from agricultural sources in Guangdong province showed phased and differentiated changes, with an overall decreasing trend in carbon emissions, fluctuating nitrogen emissions, and increasing phosphorus emissions. (2) The current coupling coordination level of carbon-nitrogen-phosphorus emissions in the province was classified as "basically coordinated." However, the coupling coordination between nitrogen and phosphorus with carbon was relatively low, categorized as "mildly imbalanced." The coupling coordination of different elements showed significant cross-level and interannual variations. (3) Although carbon, nitrogen, and phosphorus emissions from agricultural sources in Guangdong province shared some similarities, their influencing factors had different driving effects on each element. And this resulted in the independence of the coupling coordination of carbon-nitrogen-phosphorus emissions from agricultural activity factors. (4) From 2000 to 2022, the uncertainty range of carbon, nitrogen, and phosphorus emissions from agricultural sources in Guangdong province was ±22%, ±29%, and ±30%, respectively. Therefore, further research on the uncertainty of different source parameters is needed in the future, and this results can provide a scientific decision-making basis for regional agricultural source pollution reduction and carbon reduction regulation.