高伟,陈岩,严长安,赵越.长江经济带氮淋溶流失空间格局及其水环境影响评估[J].环境科学学报,2020,40(1):325-333
长江经济带氮淋溶流失空间格局及其水环境影响评估
- Evaluating spatial features of nitrogen loss in Yangtze River Economic Belt and its impact on water environment
- 基金项目：国家自然科学基金（No.41701631）；云南省基础研究计划青年项目（No.Y0120160068）
- 高伟
- 云南大学生态学与环境学院, 云南省高原山地生态与退化环境修复重点实验室, 昆明 650091
- 陈岩
- 生态环境部环境规划院长江经济带生态环境联合研究中心, 北京 100012
- 赵越
- 生态环境部环境规划院长江经济带生态环境联合研究中心, 北京 100012
- 摘要：氮淋溶流失是地表和地下水环境退化的重要驱动过程.由于氮素迁移转化过程复杂，量化氮淋溶流失及其水环境影响是区域营养盐管理的重点和难点.本研究从天然和人为输入角度构建了陆域氮淋溶流失模型，核算了2011-2015年长江经济带地级市单元的氮淋溶流失量，并基于灰水足迹和水资源量评估了氮淋溶流失的水环境影响.结果表明：①长江经济带的氮年均输入强度为8465 kg·km-2，以人为输入源为主，占总氮输入的89.9%；②研究区总氮输入的19.4%被淋溶流失到水环境中，平均淋溶流失强度为1656 kg·km-2；非点源是长江经济带的最大来源，淋溶流失系数平均值为0.143；③基于实测氮通量的反演结果与氮淋溶流失核算量存在显著的线性相关关系，表明基于氮输入核算的氮流失量能够反映氮淋溶流失空间分布规律；④长江经济带的氮淋溶流失导致的灰水足迹已经超过地区水资源总量，地级市单元的氮污染指数最高达到29.2，氮的水环境超载问题十分严重.
- Abstract：Nitrogen (N) losses by leaching and runoff are responsible for deteriorating water quality in both surface and underground waters. Due to complicated process of N migration and transformation, it is an important basis for nutrient management to quantify N loss and related impact on waters. A model for estimating N loss was constructed from the perspective of anthropogenic and natural inputs and applied in N loss calculating in Yangtze River Economic Belt to calculate its N loss from 2011 to 2015. Based on water environment pollution index, N loss effects on water environment was assessed. Results showed, ① average annual N input intensity of Yangtze River Economic Belt was 8465 kg·km-2, which was dominated by anthropogenic process and make up 89.9% of total inputs. ②19.4% of the total N input was lost to water body,with the average N loss rate of 1656 kg·km-2. Non-point source is the largest contribution for total N loss and its average loss coefficient is 0.143. ③There is a significant linear correlation between N loss calculated from observed N flux and N loss analyzed by our model, which indicated that the N loss calculating model can reflect the spatial distribution of N loss.④ In Yangtze River Economic Belt, grey water footprint of N has exceeded local water resources and the maximum water pollution index of the cities reached 29.2, indicating that N pollution has evolved as a serious environmental issue in the region.
