Dissolved inorganic carbon export from rivers of Great Britain: Spatial distribution and potential catchment-scale controls
Dissolved inorganic carbon export from rivers of Great Britain: Spatial distribution and potential catchment-scale controls
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DOI：
10.1016/j.jhydrol.2022.128677
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发表时间：
2022-11
影响因子：
6.4
通讯作者：
A. Tye;J. Williamson;H. Jarvie;N. Dise;D. Lapworth;D. Monteith;R. Sanders;D. Mayor;Michael Bowes;Michael Bowes;A. Burden;N. Callaghan;G. Farr;S. Felgate;S. Gibb;P. Gilbert;G. Hargreaves;P. Keenan;V. Kitidis;M. Jürgens;Adrian P. Martin;I. Mounteney;P. Nightingale;M. Glória Pereira;J. Olszewska;A. Pickard;Andrew P. Rees;B. Spears;M. Stinchcombe;D. White;P. Williams;F. Worrall;C. Evans
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文献类型：
--
作者：
A. Tye;J. Williamson;H. Jarvie;N. Dise;D. Lapworth;D. Monteith;R. Sanders;D. Mayor;Michael Bowes;Michael Bowes;A. Burden;N. Callaghan;G. Farr;S. Felgate;S. Gibb;P. Gilbert;G. Hargreaves;P. Keenan;V. Kitidis;M. Jürgens;Adrian P. Martin;I. Mounteney;P. Nightingale;M. Glória Pereira;J. Olszewska;A. Pickard;Andrew P. Rees;B. Spears;M. Stinchcombe;D. White;P. Williams;F. Worrall;C. Evans
溶解无机碳（DIC）从陆地到海洋的通量已被量化的全球许多河流。然而，从内陆沃茨到大气的CO2通量是全球碳循环的重要组成部分，目前制约不佳。理解，自然和人为影响的过程中的DIC循环流域内的相对贡献，可以提供一个基础，制定改进的管理策略，以减轻河流中的游离CO2浓度和随后的逃逸到大气中。在这里，一个大型的，内部一致的数据集收集了41集水区在英国（GB），占土地面积的1.36%（1.83997平方公里）和全国土地覆盖的代表，被用来调查流域控制河流溶解无机碳（DIC），碳酸氢盐（HCO3−）和游离CO2浓度，通量到沿海海和单位面积的集水区的年产量。估计调查流域的DIC入海通量为647 kt DIC yr− 1，占这些流域总溶解碳通量的69%。一般来说，那些含有大量碳酸盐和沉积砂岩的集水区被发现向海洋输送了更多的DIC和HCO3−。计算出的调查集水区的平均游离CO2产量（即向大气中的潜在CO2排放量）为0.56 t C km−2yr−1。回归模型表明，虽然河流DIC（R2= 0.77）和HCO3−（R2= 0.77）浓度在很大程度上是由陆块的地质解释的，但沿着与年降水量呈负相关，游离CO2浓度与流域常量营养素状况密切相关。总体而言，DIC占主导地位的溶解碳输入沿海沃茨，这意味着河口碳动态是敏感的底层地质，因此可能是合理的常数。相比之下，通过溶解的CO2可能损失到大气中的碳可能构成陆地生态系统净生产的很大一部分，因此也是国家碳预算的很大一部分，可以通过改变土地使用模式进行更直接的管理。
Dissolved inorganic carbon (DIC) fluxes from the land to ocean have been quantified for many rivers globally. However, CO2fluxes to the atmosphere from inland waters are quantitatively significant components of the global carbon cycle that are currently poorly constrained. Understanding, the relative contributions of natural and human-impacted processes on the DIC cycle within catchments may provide a basis for developing improved management strategies to mitigate free CO2concentrations in rivers and subsequent evasion to the atmosphere. Here, a large, internally consistent dataset collected from 41 catchments across Great Britain (GB), accounting for ∼36% of land area (∼83,997 km2) and representative of national land cover, was used to investigate catchment controls on riverine dissolved inorganic carbon (DIC), bicarbonate (HCO3−) and free CO2concentrations, fluxes to the coastal sea and annual yields per unit area of catchment. Estimated DIC flux to sea for the survey catchments was 647 kt DIC yr−1which represented 69% of the total dissolved carbon flux from these catchments. Generally, those catchments with large proportions of carbonate and sedimentary sandstone were found to deliver greater DIC and HCO3−to the ocean. The calculated mean free CO2yield for survey catchments (i.e. potential CO2emission to the atmosphere) was 0.56 t C km−2yr−1. Regression models demonstrated that whilst river DIC (R2= 0.77) and HCO3−(R2= 0.77) concentrations are largely explained by the geology of the landmass, along with a negative correlation to annual precipitation, free CO2concentrations were strongly linked to catchment macronutrient status. Overall, DIC dominates dissolved C inputs to coastal waters, meaning that estuarine carbon dynamics are sensitive to underlying geology and therefore are likely to be reasonably constant. In contrast, potential losses of carbon to the atmosphere via dissolved CO2, which likely constitute a significant fraction of net terrestrial ecosystem production and hence the national carbon budget, may be amenable to greater direct management via altering patterns of land use.