Urban development and associated land cover and land use change alter the thermal, hydrological, and physical properties of the land surface. Assessments of surface urban heat island (UHI) usually focused on using remote sensing and land cover data to quantify UHI intensity and spatial distribution within a certain period. However, the mechanisms and complex interactions in landscape dynamics and land surface thermal features are still being assessed. In this study, we developed and implemented a novel approach to characterize landscape thermal conditions by focusing on UHI intensity and its spatiotemporal variation using the recently available time series of Landsat land surface temperature and land cover change products. We analyzed land surface temperature changes in urban and surrounding non-urban lands to quantify the UHI intensity and landscape thermal conditions in the Atlanta and Minneapolis metropolitan areas of the United States. Our results revealed that UHI intensities had averages of 3.4 °C and 3.3 °C in the Atlanta and Minneapolis metropolitan areas, respectively. The dominant land cover type in rural areas and urban imperviousness cover determines the UHI intensity. Increasing trends of 0.04 °C/year and 0.01 °C/year in UHI intensity between 1985 and 2018 were found in Atlanta and Minneapolis, respectively. The UHI intensity variations in 1985 and 2018 suggest that the magnitudes and temporal variations of UHI intensity averaged from all urban land cover classes are close to the UHI intensity estimated from the low intensity urban area only while the UHI intensities are more than 2 °C larger in medium to high and high intensity urban areas. The UHI intensities estimated from the maximum temperature that have statistically significant increasing trends suggest that the maximum temperature is a good element for measuring UHI effect. Urban land cover dynamics play an important role in controlling temporal variation of UHI and the UHI hotspots. Our findings support the scientific value of implementing the prototype approach as an objective framework to quantify and monitor UHI intensity at a large geographic extent.

城市发展以及相关的土地覆盖和土地利用变化会改变地表的热力、水文和物理特性。地表城市热岛（UHI）的评估通常侧重于利用遥感和土地覆盖数据来量化一定时期内的 UHI 强度和空间分布。然而，景观动力学和地表热特征的机制和复杂的相互作用仍在评估中。在这项研究中，我们开发并实施了一种新方法，通过使用最近可用的 Landsat 地表温度和土地覆盖变化产品的时间序列关注 UHI 强度及其时空变化来表征景观热条件。我们分析了城市和周围非城市土地的地表温度变化，以量化美国亚特兰大和明尼阿波利斯大都市区的 UHI 强度和景观热条件。我们的结果显示，亚特兰大和明尼阿波利斯大都市区的 UHI 强度平均分别为 3.4 °C 和 3.3 °C。农村地区占主导地位的土地覆盖类型和城市不透水覆盖决定了 UHI 强度。1985 年至 2018 年间，亚特兰大和明尼阿波利斯的 UHI 强度分别呈 0.04 °C/年和 0.01 °C/年的增加趋势。1985 年和 2018 年的 UHI 强度变化表明，所有城市土地覆盖类别的平均 UHI 强度的大小和时间变化接近于从低强度市区估计的 UHI 强度，而 UHI 强度大于 2 °C在中高强度和高强度的城市地区。从具有统计显着增加趋势的最高温度估计的 UHI 强度表明最高温度是衡量 UHI 效应的一个很好的元素。城市土地覆盖动态在控制 UHI 和 UHI 热点的时间变化方面起着重要作用。我们的研究结果支持将原型方法作为一个客观框架在大的地理范围内量化和监测 UHI 强度的科学价值。