United States Geological Survey, California Water Science Center, 4165 Spruance Rd. Suite 200, San Diego, CA 92101, United States.
United States Geological Survey, Earth Systems Processes Division, 10 Bearfoot Rd., Northborough, MA 01532, United States.
Sci Total Environ. 2019 Oct 15;687:1261-1273. doi: 10.1016/j.scitotenv.2019.06.036. Epub 2019 Jun 6.
Domestic wells provide drinking water supply for approximately 40 million people in the United States. Knowing the location of these wells, and the populations they serve, is important for identifying heavily used aquifers, locations susceptible to contamination, and populations potentially impacted by poor-quality groundwater. The 1990 census was the last nationally consistent survey of a home's source of water, and has not been surveyed since. This paper presents a method for projecting the population dependent on domestic wells for years after 1990, using information from the 1990 census along with population data from subsequent censuses. The method is based on the "domestic ratio" at the census block-group level, defined here as the number of households dependent on domestic wells divided by the total population. Analysis of 1990 data (>220,000 block-groups) indicates that the domestic ratio is a function of the household density. As household density increases, the domestic ratio decreases, once a household density threshold is met. The 1990 data were used to develop a relationship between household density and the domestic ratio. The fitted model, along with household density data from 2000 and 2010, was used to estimate domestic ratios for each decadal year. In turn, the number of households dependent on domestic wells was estimated at the block-group level for 2000 and 2010. High-resolution census-block population data were used to refine the spatial distribution of domestic-well usage and to convert the data into population numbers. The results are presented in two downloadable raster datasets for each decadal year. It is estimated that the total population using domestic-well water in the contiguous U.S. increased 1.5% from 1990 to 2000 to a total of 37.25 million people and increased slightly from 2000 to 2010 to 37.29 million people.
美国约有 4000 万人使用家庭水井作为饮用水供应。了解这些水井的位置及其服务的人口，对于确定大量使用的含水层、易受污染的地点以及可能受到劣质地下水影响的人群非常重要。1990 年的人口普查是最后一次对家庭用水来源进行的全国性一致调查，此后再未进行过调查。本文提出了一种方法，用于根据 1990 年人口普查的数据以及随后的人口普查数据，预测 1990 年以后几年依赖家庭水井的人口。该方法基于普查街区组层面的“家庭用水比例”，定义为依赖家庭水井的家庭数量与总人口的比值。对 1990 年数据（超过 220000 个街区组）的分析表明，家庭用水比例是家庭密度的函数。随着家庭密度的增加，一旦达到家庭密度阈值，家庭用水比例就会降低。利用 1990 年的数据，建立了家庭密度与家庭用水比例之间的关系。利用拟合模型以及 2000 年和 2010 年的家庭密度数据，估计了每个十年的家庭用水比例。然后，在街区组层面估计了 2000 年和 2010 年依赖家庭水井的家庭数量。利用高分辨率的人口普查街区数据，对家庭水井使用的空间分布进行了细化，并将数据转换为人口数量。结果以每个十年的两个可下载栅格数据集呈现。据估计，1990 年至 2000 年期间，美国使用家庭水井供水的总人口增加了 1.5%，达到 3725 万人，而 2000 年至 2010 年期间，这一数字略有增加，达到 3729 万人。
