| 摘要: |
| 土地利用方式及其转移对区域氮素迁移和水体氮负荷产生重要影响，但量化自然发展、耕地保护、生态保护等多情景下土地利用方式氮排放时空变化特征，揭示流域水体氮负荷对土地利用变化的响应机制仍面临挑战。本研究以巢湖流域为研究区，通过遥感解译多时相土地利用类型数据，借助PLUS和InVEST模型探索不同情景下氮排放对各土地利用类型变化的响应机制。结果表明：（1）2000-2020年期间，巢湖流域建设用地面积的增加（626.14 km2）主要占据的是耕地（减少了775.64 km2），城市化建设成为土地利用方式变化的主要驱动力；（2）PLUS模型多情景预测结果显示：2020-2030年间土地利用变化特征与2000-2020年基本保持一致，但各用地间的转换频率降低；（3）经InVEST模拟，耕地面积缩减而导致氮排放的减少量（340.17 t N）大于建设用地等面积增加带来的氮排放增加量（170.11 t N），使2000-2020年间巢湖流域土地利用所排放的总氮量呈降低趋势，由2000年的4768.04 t N降至2020年的4597.98 t N；（4）不同情景下，2030年各土地利用方式的氮排放量较2020年均呈降低趋势。其中，生态保护情景既有效的保障了巢湖流域生态功能又展现出较好的氮减排效果（113.36 t N）；鉴于此，建议流域管理部门应通过合理规划各用地类型的发展，严格控制建设用地对林草地、水域等生态用地的侵占，以期削减流域氮素排放负荷和缓解氮素治理压力。 |
| 关键词: 巢湖流域 氮排放 土地利用方式 PLUS模型 InVEST模型 |
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| 基金项目:安徽省自然科学基金(No. 2208085QD108)、安徽省高等学校自然科学研究重点项目(No. KJ2021A1081)、空间数据挖掘与信息共享教育部重点实验室开放基金(No.2022LSDMIS04)、实景地理环境安徽省重点实验室开放基金(2022PGE005)、滁州学院科学研究项目(No. 2022qd004) |
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| Simulation of nitrogen discharge scenarios in Chaohu Lake Basin based on land use patterns |
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Dai Zishuai,Chen Xi,Jiang Ling,Ye Chun,Wang Yanhua,Huang Xiaoli,Yang Cancan,Chen Sidi
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School of Geographical Information and Tourism, Chuzhou University
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| Abstract: |
| Land use patterns and theirs conversion significantly affect the transportation and loading of nitrogen in waterbody. However, quantifying the spatiotemporal variations of nitrogen discharged from land use patterns under different scenarios, such as natural development, cultivated land protection and ecological protection, and revealing the response mechanisms of watershed nitrogen loading to land use changes remain challenging. This study focuses on the Chaohu Lake Basin as the research area, and it utilizes remote sensing techniques to interpret multi-temporal land use data and explores the response mechanism of nitrogen discharge to changes in different land use types under different scenarios using the PLUS and InVEST models. The findings reveal that: 1) Between 2000 and 2020, the expansion of construction land (626.14 km2) in Chaohu Lake Basin was primarily at the expense of cultivated land (775.64 km2), indicating that urbanization has emerged as the primary driving force behind land use change; 2) The results of the PLUS model’s multi-scenario predictions indicate that the trend of land use change between 2020 and 2030 is similar to that between 2000 and 2020. However, the frequency of conversion between different land uses is expected to decrease; 3) According to the InVEST simulation, the reduction in nitrogen discharge resulting from the reduction in cultivated land area (340.17 t N) is greater than the increase in nitrogen discharge resulting from the expansion of construction land area (170.11 t N). As a result, the total nitrogen discharged from land use in the Chaohu Basin showed a decreasing trend from 4768.04 t N in 2000 to 4597.98 t N in 2020; 4) Across different scenarios, the nitrogen discharge for all land use types in 2030 exhibited a declining trend as compared to 2020. Under the ecological protection scenario, it not only effectively preserve the ecological function of the Chaohu Lake Basin, but also results in a significant reduction of nitrogen discharge loads by 113.36 t N. Therefore, it is recommended that the river Basin management department should prudently plan the development of various land types, and strictly control the encroachment of construction land on ecological land such as forests, grasslands, and water bodies. This will help to mitigate the nitrogen discharge loads and reduce the pressure of nitrogen management. |
| Key words: Chaohu Lake Basin Nitrogen discharge Land use pattern PLUS model InVEST model |
