Georectified mosaic of historical aerial photographs of the Colorado River in Palo Verde Valley, Arizona and California, acquired in 1930

This product is a georectified and tonally balanced mosaic of aerial photographs collected in 1930 by the U.S. Bureau of Reclamation along a portion of the floodplain of the Colorado River in Palo Verde Valley, Arizona and California. This dataset is a primary resource for the development of a surficial geologic map showing the floodplain and river channel characteristics along the Colorado River in Palo Verde Valley prior to significant flow regulation by Hoover Dam, and subsequently Parker Dam and Palo Verde Dam. Mosaic generation was performed by Digital Aerial Solutions, LLC.

In addition to the mosaic, the data release also includes individual digital aerial photographs (original scans and georeferenced; see the child items) that cover the area of interest. Supplemental files include image footprints, georeferencing procedures and accuracy reports supplied by the contractor, seamlines for the mosaic, image-to-image control points, and check points. All spatial data is in the NAD 1983 UTM Zone 11N coordinate system.

本数据集为1930年由美国垦务局（U.S. Bureau of Reclamation）在亚利桑那州与加利福尼亚州帕洛弗迪谷科罗拉多河部分河漫滩区域采集的航空摄影影像，经地理校正与色调平衡处理后形成的镶嵌图。该数据集是开展地表地质填图的核心基础资料，用于绘制胡佛大坝、后续帕克大坝与帕洛弗迪大坝实施大规模径流调控前，帕洛弗迪谷地内科罗拉多河河漫滩与河道特征分布图。本镶嵌图由数字航空解决方案有限责任公司（Digital Aerial Solutions, LLC）制作完成。

除整体镶嵌图外，本次数据发布还包含覆盖研究区域的单幅数字航空摄影影像（含原始扫描件与地理配准文件，详见子项）。补充文件包括影像覆盖范围文件、承包商提供的地理配准流程与精度报告、镶嵌图拼接线、影像间控制点及检查点。所有空间数据均采用NAD 1983 UTM Zone 11N坐标系。