Du Bailin, Wu Lei, Ruan Bingnan, Xu Liujia, Liu Shuai, Guo Zongjun
Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Areas, Ministry of Education, Northwest A&F University, Yangling, Shaanxi 712100, China; College of Water Resources and Architectural Engineering, Northwest A&F University, Yangling, Shaanxi 712100, China.
Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Areas, Ministry of Education, Northwest A&F University, Yangling, Shaanxi 712100, China; State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling, Shaanxi 712100, China; College of Water Resources and Architectural Engineering, Northwest A&F University, Yangling, Shaanxi 712100, China.
Sci Total Environ. 2024 Oct 10;946:174260. doi: 10.1016/j.scitotenv.2024.174260. Epub 2024 Jun 25.
Climate and land-use changes have an overlying impact on non-point source (NPS) pollution in river basins. However, the control effect of Best Management Practices (BMPs) for NPS pollution is not yet clear under future scenarios. The Soil and Water Assessment Tool (SWAT) model was coupled with the entropy-weighted method, global climate patterns and land-use data to explore the dynamic variations in total nitrogen (TN) and total phosphorus (TP) loads in the Jing River Basin during the baseline (2000-2020) and future periods (2021-2065), evaluate the pollution reduction effectiveness of individual and combined BMPs, and propose practical BMP configurations. Results indicate that a future trend of urban land expansion, particularly in the economic scenario (LU_SSP585), leads to weakened environmental ecosystems, while the sustainable scenario (LU_SSP126) exhibits more balanced land development. The MIROC-ES2L model demonstrates higher Taylor skill scores, forecasted significant increases in precipitation, maximum, and minimum temperatures under the SSP585 scenario. Spatial heterogeneity in TN and TP loads is notable, showing an upward trajectory in the future. The interaction between land-use and climate change has complex effects on TN and TP loads, with land-use-induced TN changes being relatively small (4.6 %) and TP changes substantial (24.3 %). The spatial distribution, under overlying effects, leans towards the influence of climate change, emphasizing its dominant role in TN and TP load variations. Distinct differences exist in the reduction of NPS pollution loads among different BMPs, with combined BMPs demonstrating superior effectiveness. The environmental-cost effectiveness trends of BMPs remain consistent across various future scenarios. RG (Return agricultural land to grass), RG + TT (Terracing), and RG + FR10 (Fertilizer reduction: 10 %) + GW (Grassed waterway) + FS (Filter strip) + TT emerge as the most effective single, double, and multiple BMP combinations, respectively. The results offer valuable insights for preventing and mitigating future NPS pollution risks, optimizing land-use layouts, and enhancing watershed management decisions.
气候和土地利用变化对流域非点源（NPS）污染具有叠加影响。然而，在未来情景下，最佳管理实践（BMPs）对NPS污染的控制效果尚不清楚。将土壤和水资源评估工具（SWAT）模型与熵权法、全球气候模式和土地利用数据相结合，以探究泾河流域在基准期（2000 - 2020年）和未来时期（2021 - 2065年）总氮（TN）和总磷（TP）负荷的动态变化，评估单个和组合BMPs的污染减排效果，并提出切实可行的BMP配置方案。结果表明，未来城市土地扩张趋势明显，尤其是在经济情景（LU_SSP585）下，这会导致环境生态系统弱化，而可持续情景（LU_SSP126）则呈现出更为平衡的土地发展态势。MIROC - ES2L模型显示出更高的泰勒技能分数，预测在SSP585情景下降水量、最高和最低气温将显著增加。TN和TP负荷的空间异质性显著，未来呈上升趋势。土地利用和气候变化之间的相互作用对TN和TP负荷具有复杂影响，土地利用引起的TN变化相对较小（4.6%），而TP变化较大（24.3%）。在叠加效应下，空间分布倾向于受气候变化的影响，强调其在TN和TP负荷变化中的主导作用。不同BMPs在减少NPS污染负荷方面存在明显差异，组合BMPs显示出更高的有效性。BMPs的环境成本效益趋势在各种未来情景下保持一致。退耕还草（RG）、退耕还草 + 梯田（RG + TT）以及退耕还草 + 减施10%化肥（RG + FR10）+ 种草沟（GW）+ 过滤带（FS）+ 梯田（TT）分别成为最有效的单一、双重和多重BMP组合。这些结果为预防和减轻未来NPS污染风险、优化土地利用布局以及加强流域管理决策提供了有价值的见解。
