Outdoor water use represents over 50% of total water demand in semiarid and arid cities and presents both challenges to and opportunities for improved efficiency and water resilience. The current work adapts a remote sensing‐based methodology to estimate growing season irrigation rates at the census block group scale in Denver, Colorado. Results show that city‐wide outdoor water use does not change significantly from 1995 to 2018, while per capita water use and total water use significantly decrease from 2000 to 2018. Because total water use, but not outdoor use, is decreasing, the percent of water used outdoors significantly increases across the city from 2000 to 2018. Climate variables account for one‐quarter of interannual variation in mean irrigation rates due primarily to changes in temperature, not precipitation. Percent impervious land cover exhibits a significant inverse nonlinear relationship with irrigation rates at the census block group scale. Finally, 38% of Denver census block groups show significantly increasing irrigation rates between 1995 and 2018 driven primarily by increasing temperatures. The increasing proportion of water used for irrigation highlights the importance of outdoor demand management for urban water systems as indoor efficiencies improve. We advocate that resilient water systems necessitate integrated land use, infrastructure, and water planning in the face of urban growth and climate change. While minimizing irrigated urban areas may reduce demand, remaining green spaces should be designed to maximize multiple benefits including reductions in water demand and urban heat islands, stormwater management, and recreation to improve the sustainability of growing cities.

中文翻译：

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洒水卫星：评估气候和土地覆盖变化对城市室外用水模式的作用

在半干旱和干旱的城市中，室外用水占总需水量的50％以上，这对于提高效率和抗水能力既是挑战，又是机遇。目前的工作采用基于遥感的方法，以估算科罗拉多州丹佛市人口普查组规模的生长季灌溉率。结果表明，从1995年到2018年，城市范围内的室外用水量没有显着变化，而从2000年到2018年，人均用水量和总用水量显着下降。由于总用水量（而不是室外用水量）正在减少，因此从2000年到2018年，整个城市的室外用水量显着增加。气候变量占平均灌溉速率年际变化的四分之一，这主要是由于温度变化而不是降水变化引起的。在人口普查区组尺度上，不透水土地覆盖率与灌溉速率之间呈现出显着的逆非线性关系。最后，在1995年至2018年之间，丹佛人口普查区组中有38％的灌溉率显着增加，主要原因是温度升高。用于灌溉的水的比例不断增加，凸显了随着室内效率的提高，室外需求管理对城市供水系统的重要性。我们主张，面对城市增长和气候变化，有韧性的水系统必须综合利用土地，基础设施和水规划。虽然尽量减少灌溉用水面积可能会减少需求，但应设计剩余的绿色空间，以最大程度地提高多种效益，包括减少需水量和减少城市热岛，雨水管理，