POPULATION AND ENVIRONMENT IN THE U.S. GREAT PLAINS

这是一个正在进行的项目，旨在继续对美国大平原人口、农业土地利用和环境之间关系的长期方面进行多学科研究。这一地区很重要，因为大平原的草原覆盖了美国的大部分地区，而且容易受到环境变化的影响。拟议的研究涉及对该区域的人口经验和环境变化的审查。该项目的理论基础借鉴了许多来源，并针对人口和环境递归变化的模型，其中一个因素在一个时间段内的变化会在随后的一个时间段影响另一个因素，以此类推。该项目将加强一个已经开发的数据库，该数据库包含有关人口、土地利用和环境及其社会背景的县级信息。新的分析将通过各种衡量标准，包括人口密度、社会、职业、种族、年龄和性别结构以及家庭动态，来考察环境变化和变化对人口结构的影响。其他新的分析将着眼于土地利用的结果，包括土地利用从农业向非农业的转变。这项工作将使用考虑到空间和时间影响的最先进的统计数据。这项研究将继续验证研究结果，并通过对大平原内社区的深入研究来发展假设。在最初的项目期间开展的农场家庭研究将继续提供关于农场家庭在其环境和社会背景下的行为的见解。这项研究的一个重要成果将是对大平原自1880年以来土地利用和农业技术变化的新概述。这一历史将用人口普查积累的人口和农业数据来验证。该项目的最后阶段将是在这些分析之后进行模型建立和模拟工作，首先将使用世纪土壤模型系统建立环境变化的长期模型。调查人员还将整合人口和环境变化的分析，方法是建立一个人口和社会变化部分，将其添加到世纪模型中，并将建模工作的结果与大平原的历史记录进行比较。

This is an ongoing project to continue a multidisciplinary study of long-term aspects of the relationship between population, agricultural land use, and the environment in the Great Plains of the United States. This region is important because the grasslands of the Great Plains cover a large part of the U.S., and are subject to environmental variability. The proposed research involves an examination of the demographic experience of the region and of changes in the environment. The theoretical basis of the project draws on many sources, and is directed toward a model of recursive change in population and environment, one in which changes in one of these factors in one time period influence the other in a subsequent time period, and so on. This project will enhance an already developed database that contains county-level information about population, land use, and environment, and their social context. New analyses will look at the demographic impact of environmental variation and change through a variety of measures, including population density, social, occupational, ethnic, age and sex structures, and the dynamics of families. Other new analyses will look at land use outcomes, including the transformation of land use from agricultural to non-agricultural. This work will use of state- of-the-art statistics that take into account spatial and temporal effects. The study will continue to validate findings and develop hypotheses with in-depth research about communities within the Great Plains. The Farm Family Study, mounted during the initial project period, will continue to provide insights about the behavior of farm families within their environmental and social contexts. One important outcome of the research will be a new overview of changing land use and agricultural technology in the Great Plains since 1880. This history will be validated with the accumulated data about population and agriculture from the censuses. The final stage of the project will be to follow these analyses with a model-building and simulation exercise that will first build long-term models of environmental change using the CENTURY soil model system. The investigators will also integrate the analysis of demographic and environmental change by building a demographic and social change component to add to the CENTURY model, and comparing the results of the modeling exercise with the historical record for the Great Plains.