We evaluate two mitigation strategies for urban heat island (UHI) in the Kansas City Metropolitan Area (KCMA). Using the Weather Research and Forecasting (WRF) model, we assess the potential benefits of reflective "cool" roofs and urban irrigation on air temperature in typical summer conditions between 2011 and 2015, and during six of the strongest historical heat waves from 2005 to 2016. Under the typical summer conditions, we simulate 2-m air temperature for 10 summer weeks, finding average daytime (07:00–19:00 local time) temperature reductions of 0.08 and 0.28 °C for cool roofs and urban irrigation, respectively. During the six heat-wave episodes, we find daytime temperature reductions of 0.02 and 0.26 °C for the two scenarios, similar to those under typical summer conditions. Our results suggest that urban irrigation can be more efficient than cool roofs in mitigating UHI in metropolitan regions where the majority of the land cover is comprised of areas with low urban (i.e., non-vegetated) fractions. Finally, we find the alteration of surface conditions due to enhanced roof albedos influences precipitation within the WRF simulation, in particular during the heat waves. Further research would be necessary to determine the robustness of this last finding.

我们评估了堪萨斯城都会区（KCMA）的城市热岛（UHI）的两种缓解策略。使用天气研究与预测（WRF）模型，我们评估了2011年至2015年之间典型夏季条件下以及2005年至2016年六次最强历史热浪期间，反射型“凉爽”屋顶和城市灌溉对气温的潜在好处。在典型的夏季条件下，我们模拟了10个夏季周的2 m气温，发现凉爽的屋顶和城市灌溉的平均白天（本地时间07：00-19：00）降温分别为0.08和0.28°C。在这六个热浪事件中，我们发现两种情况下白天的温度分别降低了0.02和0.26°C，这与夏季典型情况相似。我们的结果表明，在大面积土地覆盖率低的城市（即非植被）地区组成的大都市地区，城市灌溉在降低UHI方面要比凉爽的屋顶更为有效。最后，我们发现由于增强的屋顶反照率影响了WRF模拟（特别是在热浪期间）内的降水，从而改变了地面条件。为了确定这一最后发现的鲁棒性，有必要进行进一步的研究。