Recent deforestation rates in Cambodia are among the world’s largest, while hydropower development has accelerated in the Mekong region. Deforestation accelerates erosion, increasing river sediments heading to reservoirs and decreasing hydropower production. Forest protection could be seen as a service to hydropower, which the FOR-POWER model quantifies. Using recent deforestation estimates, annual sediment accumulation is calculated, followed by associated power generation loss, and annualized and present monetary value associated with benefits of forest conservation to hydropower. We evaluated four proposed medium-size hydropower dams (20–24 MW; 6–145 m³/s design discharge), and found that extensive deforestation could result in annual sediment accumulation of 360–930 million tons (reservoir dependent), but only 140–750 million tons in a forest conservation scenario. Overall, these reservoirs could lose 60–100% of storage capacity over 120 years at current deforestation rates, resulting in power loss net present values for Pursat-I, Battambang I and II dams of US $2.58, $44.8 and $28.8 million, respectively. A global sensitivity analysis showed that FOR-POWER was particularly sensitive to discount rates and electricity prices. The modeling tool developed for this study is transferable to other dams globally where hydropower development is accelerating and in need for better quantifying ecosystem services from surrounding watersheds.

柬埔寨最近的森林砍伐率是世界上最高的，而湄公河地区的水力发电发展已加速。森林砍伐会加速侵蚀，增加流向水库的河流沉积物，并降低水力发电量。森林保护可以看作是对水电的一种服务，FOR-POWER模型对此进行了量化。使用最新的森林砍伐估算，可以计算出每年的沉积物积累量，然后是相关的发电量损失，以及与森林保护对水电的收益相关的年度和当前货币价值。我们评估了四个拟建的中型水电大坝（20-24 MW； 6-145 m ³/ s设计排放量），并发现大规模的森林砍伐可能导致每年沉积物积累360–9.3亿吨（取决于储层），但在森林保护方案中只有140–7.5亿吨。总体而言，按当前的森林砍伐速度，这些水库在120年内可能损失60–100％的存储容量，导致Pursat-I，Battambang I和II大坝的电力损失净现值分别为2.58美元，44.8美元和2880万美元。一项全球敏感性分析表明，FOR-POWER对折现率和电价特别敏感。为该研究开发的建模工具可移植到全球其他水坝，在这些大坝中水电开发正在加速，需要更好地量化周围流域的生态系统服务。