Soil erosion and sediment transport in Tanzania: Part I - sediment source tracing in three neighbouring river catchments
Soil erosion and sediment transport in Tanzania: Part I - sediment source tracing in three neighbouring river catchments
复制标题
坦桑尼亚的土壤侵蚀和沉积物输送：第一部分 - 三个邻近河流流域的沉积物来源追踪
DOI：
10.1002/esp.5217
复制
发表时间：
2021
影响因子：
3.3
通讯作者：
Wynants M
中科院分区：
文献类型：
--
作者：
Wynants M
坦桑尼亚的水体正在经历越来越多的淤积，这威胁到该地区的水质、生态系统健康和生计安全。造成这种现象的原因是上游土壤侵蚀和下游泥沙输移的速率增加。然而，由于缺乏对不同集水区、土地利用类型和主要侵蚀过程对输送沉积物的贡献的了解，从问题的根源上阻碍了土壤退化的缓解。在这方面，在坦桑尼亚的三个河流系统中采用了补充性的沉积物来源追踪技术，以进一步了解该区域土壤侵蚀和沉积物迁移的复杂动态。地球化学和生物化学指纹分析揭示了一个高度复杂和可变的土壤系统，可以分为不同的类。这些土壤类unmixed对河流沉积物指纹使用贝叶斯MixSIAR模型，每个集水区产生比例源的贡献。这种泥沙来源追踪表明，在采样时间段内，中部地区开放牧场和玉米农田的山坡侵蚀贡献了所有三个河流系统中75%以上的输沙量。通过将地球化学和生物化学指纹与沉积物来源追踪技术相结合，这项研究证明了坦桑尼亚土地利用、土壤侵蚀和下游沉积物迁移之间的联系。这一证据可以指导土地管理者设计有针对性的干预措施，以保护土壤健康和水质。
Water bodies in Tanzania are experiencing increased siltation, which is threatening water quality, ecosystem health, and livelihood security in the region. This phenomenon is caused by increasing rates of upstream soil erosion and downstream sediment transport. However, a lack of knowledge on the contributions from different catchment zones, land‐use types, and dominant erosion processes, to the transported sediment is undermining the mitigation of soil degradation at the source of the problem. In this context, complementary sediment source tracing techniques were applied in three Tanzanian river systems to further the understanding of the complex dynamics of soil erosion and sediment transport in the region. Analysis of the geochemical and biochemical fingerprints revealed a highly complex and variable soil system that could be grouped in distinct classes. These soil classes were unmixed against riverine sediment fingerprints using the Bayesian MixSIAR model, yielding proportionate source contributions for each catchment. This sediment source tracing indicated that hillslope erosion on the open rangelands and maize croplands in the mid‐zone contributed over 75% of the transported sediment load in all three river systems during the sampling time‐period. By integrating geochemical and biochemical fingerprints in sediment source tracing techniques, this study demonstrated links between land use, soil erosion and downstream sediment transport in Tanzania. This evidence can guide land managers in designing targeted interventions that safeguard both soil health and water quality.