Lake Bunyonyi is one of the major resources of social-economic potential in the districts of Rubanda and Kabale, South-Western Uganda. The lake’s sub-catchment faces environmental problems because of intensive agriculture, settlement, business and tourism activities, which consequently cause pollution of water in the lake’s system. This study, therefore, intended to determine the processes that govern nitrogen dynamism using a numerical model that takes into account various processes in the system using STELLA® 8.1.1 software. From the model simulation, it was found that mineralization, microbial uptake and nitrification were the major processes governing nitrogen transformation in the water phase, accounting for 47.8% (0.49 g/d m⁻²), 44.2% (0.45 g/d m⁻²), and 7.8% (0.05 g/d m⁻²), respectively. The developed model predicted reasonably well the behaviour of the lake evidenced by the validation results of observed and simulated data that showed good linear regression coefficients (R²) of organic nitrogen (0.48), ammonia–nitrogen (0.68), and nitrate–nitrogen (0.61). The model has proven suitable for application on lakes with characteristics similar to that of Lake Bunyonyi. The study recommended that a compressive investigation that puts into consideration all the possible sources of nutrient and water inflow into the lake system be done on Lake Bunyonyi.

Bunyonyi 湖是乌干达西南部鲁班达和卡巴莱地区具有社会经济潜力的主要资源之一。由于集约化的农业、居民点、商业和旅游活动，该湖子流域面临环境问题，从而导致湖系统水体污染。因此，本研究旨在使用一个数值模型确定控制氮活力的过程，该模型考虑到使用 STELLA® 8.1.1 软件的系统中的各种过程。模型模拟发现，矿化、微生物吸收和硝化作用是控制水相氮转化的主要过程，分别占47.8%（0.49 g/dm ^-2）、44.2%（0.45 g/dm ^-2） , 和 7.8% (0.05 g/dm^-2 )，分别。所开发的模型对湖泊的行为进行了合理的预测，观测和模拟数据的验证结果证明了有机氮（ 0.48 ^）、氨氮（0.68）和硝酸盐氮（ 0.61)。该模型已被证明适用于具有与布尼奥伊湖相似特征的湖泊。该研究建议对布尼奥伊湖进行压缩调查，考虑所有可能的营养物质和流入湖泊系统的水源。