Modeled Streamflow Change Metrics

Overview This service presents modeled streamflow change metrics for streams across the contiguous United States. It visualizes percent change in flow conditions between historical and mid-century climate periods for a range of seasonal and hydrologic indicators. Layers The service includes multiple stream line layers and grouped flow-surface layers for a set of modeled metrics. The stream layers show National Hydrography Dataset flowlines with attributes for mean annual, monthly, seasonal, flood, drought, and low-flow metrics. The grouped image layers display percent change surfaces for: Mean annual, winter, spring, summer, and fall flow 1.5-year, 10-year, and 25-year flood conditions 1-year and 10-year minimum weekly flow Characteristics The mapped stream network contains polyline features symbolized by class breaks on the selected flow-change metric. The image layers present gridded percent change values, with each pixel representing the modeled change in flow metric class for a given location. The service supports map display, feature and image queries, and data access. Temporal summary: The service is based on historical and projected climate periods, including 1977–2006 and mid-century projections for 2030–2059. The layers summarize change over time in streamflow conditions and support visual comparison of seasonal and hydrologic change patterns. Image interpretation: The image layers represent modeled percent change in streamflow metrics across the United States, with values organized into visual classes for flow increase or decrease patterns at the displayed resolution. Geographic Coverage The service covers the contiguous United States in NAD 83 geographic coordinates, with stream and grid coverage spanning the national river network from the western to eastern conterminous states. Use Cases This service supports visualization and review of climate-driven changes in streamflow, seasonal flow regimes, flood conditions, drought indicators, and minimum flow patterns for hydrologic analysis, watershed planning, and natural resource assessment. Data source: USDA Forest Service modeled streamflow metrics for National Hydrography Dataset stream segments.