CARBON TRANSFORMATIONS IN THE TROPICAL SILICATE-DOMINATED DEDURU OYA CATCHMENT, SRI LANKA (C-TROPIC-TRANS)

斯里兰卡以硅酸盐为主的热带 Deduru Oya 流域的碳转化 (C-TROPIC-TRANS)

• 批准号: 495057577
• 负责人: Professor Johannes Barth, Ph.D.
• 金额: --
• 依托单位: Lehrstuhl für Angewandte Geologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/495057577?language=en
• 关键词: CARBON; TRANSFORMATIONS; TROPICAL; SILICATE; DOMINATED

Carbon transfer and transformations in rivers are important reflectors of land use, weathering and climate effects. Such carbon systematics equally reflect river ecosystem and catchment health in an integral manner. A global uncertainty in this context includes extensive losses of CO2 from rivers that have mostly been budgeted on large river systems. However, smaller rivers and streams have hardly been investigated in this way so far. In particular, this lack of investigations applies to rivers from small catchments that directly discharge to the oceans. Here we propose a new investigation of carbon transformations in the tropical Deduro Oya catchment (Sri Lanka). This study would offer new insights into tropical functioning with respect to carbon transformations of a silicate-dominated lithology. Moreover, the work aims to investigate typical regional agricultural practices such as rice paddy growth that likely influences carbon spiraling within the river. Other factors such as reservoirs and multiple small water retention systems along the river as well as sewage inputs are equally planned for investigation in this monsoon-driven system. Planned geochemical tools include concentration analyses of dissolved and particulate carbon (DOC, DIC and POC) together with their stable isotopes on river and groundwater samples. This will combine with field parameters, water isotopes and major- as well as trace element analyses. Expected data will offer modelling on CO2 degassing from the water phase. Similar approaches on other aquatic systems have helped to outline natural and anthropogenic influences on aquatic carbon balances between important ecological factors such as photosynthesis and respiration. When transposed to the Deduru Oya catchment, these techniques can help to define a so far hardly known endmember of a tropical medium-sized catchment that discharges directly to the ocean with respect to river functioning in the terrestrial carbon cycle.

河流中的碳转移和转化是土地利用、风化和气候效应的重要反映。这样的碳系统同样反映河流生态系统和集水区健康的整体方式。在这方面的一个全球不确定性包括大部分预算用于大型河流系统的河流造成的大量CO2损失。然而，迄今为止，较小的河流和溪流几乎没有以这种方式进行过调查。特别是，这种缺乏调查适用于直接排入海洋的小集水区的河流。在这里，我们提出了一个新的调查在热带Deduro Oya流域（斯里兰卡）的碳转化。这项研究将提供新的见解热带功能方面的碳转化的硅酸盐为主的岩性。此外，这项工作的目的是调查典型的区域农业实践，如水稻种植可能会影响河流内的碳螺旋。其他因素，如水库和多个小型蓄水系统沿着以及污水输入同样计划在这个季风驱动的系统进行调查。计划中的地球化学工具包括对河流和地下水样品中溶解碳和颗粒碳（DOC、DIC和POC）及其稳定同位素的浓度分析。这将联合收割机与现场参数、水同位素和主要及微量元素分析相结合。预期的数据将提供从水相脱气CO2的建模。针对其他水生系统的类似方法有助于概述自然和人为对光合作用和呼吸等重要生态因素之间水生碳平衡的影响。当转移到Deduru Oya集水区，这些技术可以帮助确定一个迄今为止几乎不知道的热带中型集水区，直接排放到海洋的河流功能在陆地碳循环的端元。