Agent-Based Model to Manage Household Water Use Through Social-Environmental Strategies of Encouragement and Peer Pressure

Municipal water managers use demand-side strategies to reduce water demand needs in order to meet the available supply. Demand-side strategies can include increasing the cost of use to drive conservation, offering rebates on upgrading inefficient appliance’s to more effective and lower use versions, and public outreach programs that educate the population on the benefits of water conservation. However, each of these strategies look at appliance retrofits, not behavioral changes. Managers could increase the effectiveness of existing strategies with more information on how, why, and when users decide to reduce their own water use. This project introduces an agent-based model (a type of computational method that uses autonomous beings for the purpose of assessing their emergent effects on the whole system) to addresses how to quantify phycological factors of the household decision making process when it comes to adopting new water conservation techniques. This was accomplished by introducing three new survey derived behavioral attributes (attitudes, peer support, opportunities) and building social-environmental management strategies (encouragement, peer pressure) that capitalize on the strengths of those behaviors. Project input data was specific to Logan, Utah and comes from several sources (iUTAH 2014 survey, the Utah Mapping Portal, local weather monitoring stations, and studies of indoor water use). Results were as follows. Validation between model water use and municipal billing data worked well for indoor use with the matching of appliances to the household occupancy size as the high-frequency data set used was a good representation of indoor water use. Outdoor use validation was complicated due to the difficulty of limiting the wide variation in plant and soil composition, landscape watering methods including secondary water use, and over- and under- watering between household users. Quantified psychological factors on water use showed that the encouragement strategy reduced water use because it could be tailored to target different levels of water users, the peer pressure strategy reduced more because it could self-regulate outliers providing the networks were small and diverse, and combining both strategies saved the most because when working in tandem they increased the number of exchanges occurring which helped overcome limitations of the strategy implemented alone. Mangers can focus policy on these users by implementing a target use based on household size and observable landscape size and by recommending opportunities to conserve water through monthly bills. Managers should provide a framework for households to share their water use stories and information on new water wise techniques households have yet to adopt.

市政水务管理者采纳需求侧策略以降低用水需求，旨在满足现有供水量。需求侧策略包括提高用水成本以促进节水、提供升级低效设备至高效低耗版本时的补贴，以及通过公众宣传项目教育民众节水之益。然而，这些策略均着眼于设备改造，而非行为改变。管理者可通过获取更多关于用户如何、为何以及何时决定减少自身用水量的信息，来增强现有策略的效果。本项目引入了一种基于智能体的模型（一种利用自主实体以评估其对整个系统涌现效应的计算方法），旨在量化家庭在采用新型节水技术时决策过程中的心理因素。这通过引入三种新的基于调查得出的行为属性（态度、同伴支持、机会）并构建利用这些行为优势的社会环境管理策略（鼓励、同伴压力）来实现。项目输入数据针对犹他州的洛根市，来源于多个渠道（iUTAH 2014 调查、犹他州地图门户、当地气象监测站和室内用水研究）。结果如下。模型用水与市政计费数据的验证对于室内用水效果良好，因为所使用的频繁数据集良好地代表了室内用水情况。室外用水的验证由于难以限制植物和土壤组成的广泛差异、景观灌溉方法包括二次用水以及家庭用户之间的过度或不足灌溉而变得复杂。量化用水心理因素表明，鼓励策略通过针对不同用水级别进行定制而降低了用水量，同伴压力策略降低得更多，因为它能够自我调节异常值，前提是网络规模小且多样化，而结合两种策略则节省最多，因为当协同作用时，它们增加了交换次数，有助于克服单独实施策略的局限性。管理者可以通过实施基于家庭规模和可观察景观规模的靶向用水政策，并推荐通过月度账单节约用水的机会，来重点关注这些用户。管理者应提供一个框架，让家庭分享他们的用水故事以及关于尚未采用的新型节水技术的信息。