Abstract Water security, a key policy objective for sustainable development, is under stress as a result of land use and climate change, especially in (semi-)arid areas like Iran. Land use change alters surface runoff and affects basin-wide hydrological processes and water consumption, while climate change modifies precipitation and temperature patterns and consequently evapotranspiration and water supply. In this study, water yield, supply and consumption are simulated in a watershed draining into the Caspian Sea in northern Iran, using the water yield model in the Integrated Valuation of Environmental Service and Tradeoffs (InVEST) tool. The novelty of this study is found in the combined modelling of the impacts of climate and land use change scenarios on water security, translating these results into a water stress indicator, and estimating the associated economic costs of reduced future water supply. The results show substantial spatial variation of the negative impacts of water supply and future water security across the watershed, further increasing the pressure on its inhabitants, their economic activities and ecological values. The estimation of the economic costs of increased water insecurity allows us to inform policy and decision-makers about future investments in climate adaptation and mitigation.

中文翻译：

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使用 InVEST 模拟气候和土地利用变化对半干旱森林流域水安全的影响

摘要 水安全是可持续发展的一个关键政策目标，由于土地使用和气候变化，特别是在伊朗等（半）干旱地区，水安全正面临压力。土地利用变化会改变地表径流并影响流域范围内的水文过程和用水量，而气候变化会改变降水和温度模式，从而改变蒸散和供水。在本研究中，使用环境服务和权衡综合评估 (InVEST) 工具中的产水量模型，模拟了流入伊朗北部里海的流域中的产水量、供应量和消耗量。这项研究的新颖之处在于气候和土地利用变化情景对水安全影响的综合建模，将这些结果转化为水资源压力指标，估计未来供水减少的相关经济成本。结果表明，整个流域的供水和未来水安全的负面影响存在显着的空间变化，进一步增加了对其居民、他们的经济活动和生态价值的压力。对水不安全加剧的经济成本的估计使我们能够向政策制定者和决策者通报未来在气候适应和减缓方面的投资。