Population and Environment in the U.S. Great Plains

项目描述（由申请人提供）：本项目将继续开展一个长期的跨学科项目，研究美国大平原人口、农业用地利用和环境之间的关系。项目早期阶段已经建立了数据库和跨学科研究团队，并发表了重要的研究成果。它也揭示了继续研究的丰富机会。在该项目的早期阶段建立的一个大型数据库的基础上，拟议的研究将基于解释的航空摄影和卫星图像，开发一个从20世纪30年代到2005年的整个地区的土地利用和土地覆盖（LULC）数据样本。这种深度时间序列的LULC数据将使我们能够制定具体的假设，并调查规模在每个假设中的作用。关键论点认为，大平原地区的很大一部分从未从草原转变为农田。尽管自20世纪40年代以来该地区的农场规模发生了巨大的调整，但LULC数据将使我们能够检验农业的空间位置是否保持固定。新的数据还将用于其他分析，包括与灌溉有关的土地利用变化、人口变化以及野生动物的丰富程度和多样性。LULC数据还将加强将家庭形成历史和人口动态与环境影响和变化规模的变化联系起来的一系列研究。这项研究还将建立在一套新创建的生物地球化学模型的基础上，用于整个地区产生区域范围和次区域的长期碳和氮预算。营养预算研究将允许研究人员通过探索由当地人口变化（如城市化和郊区化）驱动的环境变化的相对影响，来研究人类与环境相互作用的规模问题，而不是驱动市场的全球变化（例如那些刺激牲畜生产或灌溉农业增长的变化）。

DESCRIPTION (provided by applicant): This project will continue a long-term interdisciplinary project that studies the relationship between population, agricultural land use, and environment in the Great Plains of the U.S. Earlier phases of this project have led to the development of data bases and an interdisciplinary research team, and to the publication of important research findings. It has also revealed rich opportunities for continued research. Building on a large data base created in earlier phases of the project, the proposed research will develop a sample of land use and land cover (LULC) data across the region based on interpreted aerial photography and satellite imagery, for the time period from the 1930s through 2005. This deep time series of LULC data will enable us to develop specific hypotheses and to investigate the role of scale in each. The key thesis asserts that a substantial portion of the Great Plains region has never been converted from grassland to cropland. The LULC data will allow us to test whether the spatial location of agriculture has remained fixed, despite the tremendous adjustment of farm size in the region since the 1940s. The new data will also be used for other analyses, including land use change associated with irrigation, demographic change and the abundance and diversity of wildlife. The LULC data will also enhance a body of research that relates the history of family formation and population dynamics to variations in the scale of environmental impacts and change. The research will also build on a newly-created set of biogeochemical models for the entire region to produce region-wide and sub-regional long-term carbon and nitrogen budgets. The nutrient budget research will allow the investigators to study issues of scale in human-environment interactions by exploring the relative impact of changes in the environment that are driven by local population change (such as urbanization and suburbanization), as opposed to global changes that drive markets (for example those that spur the growth of livestock production or irrigated agriculture).