Lake Kivu is a 485 m deep, Central-East African rift lake with huge amounts of carbon dioxide and methane dissolved in its stably stratified deep waters. In view of future large-scale methane extraction, one-dimensional numerical modelling is an important and computationally inexpensive tool to analyze the evolution of stratification and the content of gases in Lake Kivu. For this purpose, we coupled the physical lake model Simstrat to the biogeochemical library AED2. Compared to an earlier modelling approach, this coupled approach offers several key improvements, most importantly the dynamic evaluation of mixing processes over the whole water column, including a parameterization for double-diffusive transport, and the density-dependent stratification of groundwater inflows. The coupled model successfully reproduces today's near steady-state of Lake Kivu, and we demonstrate that a complete mixing event ∼2000 years ago is compatible with today's physical and biogeochemical state.

基伍湖是一个深 485 m 的中-东非裂谷湖，在其稳定分层的深水中溶解了大量的二氧化碳和甲烷。鉴于未来大规模提取甲烷，一维数值模拟是分析基伍湖分层演变和气体含量的重要且计算成本低的工具。为此，我们将物理湖模型 Simstrat 耦合到生物地球化学库 AED2。与早期的建模方法相比，这种耦合方法提供了几个关键的改进，最重要的是对整个水体混合过程的动态评估，包括双扩散传输的参数化，以及地下水流入的密度相关分层。耦合模型成功再现今天'