Methods to depict the connectedness of rock units across fault and fracture zones, allowing us to determine the distribution of geologic units, structural features, and other controlling factors, such as porosity and permeability.
Software based on the MODFLOW modeling framework, used for studies of saltwater intrusion coastal aquifers, storage and recovery in brackish limestone aquifers, and brine migration in continental aquifers.
The USGS Surface-water quality and flow Modeling Interest Group (SMIG) is interested in surface-water quality and flow modeling activities with links to articles, model archives, data archives, clearinghouse, mailing list, classes, and meetings.
Mathematical model of the groundwater system in this area includes 13 types of data and spans multiple aquifers over more than a century. This enables us to assess the quantity of groundwater, where and how it is being used, and how pumping affects it.
Recent physical changes over time, including trends toward earlier snowmelt runoff, decreasing river ice, and increasing spring water temperatures, may affect salmon populations; we want to know how important these effects are.
Complex geographic information can be analyzed with mathematical models to show us the spatial patterns of human building, vegetation growth, and other landscape characteristics that may result from environmental changes we may expect in the future.
Provides standards and guidance for measuring, estimating, collecting, and analyzing water-use data. Includes brief descriptions of water-use activities, commonly used water-use terminology, and approaches and methods used in estimating water use.
This report presents a visual, statistical presentation of five modeled flow-management alternatives and two reference alternatives for four selected sites on the Lower Missouri to aid in decision making for flow management of the river.
Description of the development and use of models to study watersheds supporting a broad range of applications and user skills. Includes links to related memos, training, software, projects, and references
Links to published materials produced by the Watershed Processes and Modeling Project on watershed model TOPMODEL, compilation of STATSGO soils data, climate change, landscape heterogeneity in ecoregions, and other links.
Wildlife you see in a national park or other reserved area don't know about the park boundary. Bobcat, martens, mink, and moose need different types of living space and habitat. Development outside the park affects their ability to inhabit the park.
Congress asked us (in the Energy Independence and Security Act of 2007) to figure out how to assess the effects of carbon storage, sequestration, and greenhouse gas fluxes in our ecosystems. Here's how we plan to do that.
Well vulnerability results from the young age of groundwater. Karst features permit contaminants to move into the aquifer easily, leading to a well mixed aquifer; geochemical processes do not degrade contaminants quickly.
Using ground-water geochemical analyses, and mathematical models, the factors affecting the quality of public water supply were identified as pumping schedule, screened interval, past land use within the recharge area, and natural geochemical conditions.
Using ground-water geochemical analyses and mathematical models, the factors affecting the quality of public water supply were identified as mixing of very recent recharge with older water, karst features, natural geochemical processes, and pumping.
Explains the natural and human-affected factors that determine the concentration of contaminants in groundwater, especially where the concentration is different at the surface than at depth, and where pumping varies with time.