This
viewer offers online access to a number of hydrologic tools for Kentucky.
This is a work in progress by the USGS
Kentucky Water Science Center and others. The tool will grow and be
modified over time. We would appreciate any feedback you have on improving
the site. Thanks in advance!
[Click Here] to e-mail us your thoughts.
Use the menus and tools provided below to access this internet mapping tool.
How to Use this Tool
1. Zoom into the area of interest (the hydrologic data show up only under a scale of 1:48,000, see scale at bottom of map).2. Check the legend on the left to make sure the data layer that you want is active. Stream Data is the default.
'Low-flow and mean annual flow' is a vector data set consisting of COLOR lines representing streams in Kentucky. We recommend viewing this layer with the 'Stream Data' layer turned off. Each line segment is attributed with the 7-day 2-year low-flow frequency values (lf7Q2), 7-day 10-year low-flow frequency values (lf7Q10), and the mean annual streamflow values (MEAN_ANNUAL_FLOW) for the downstream end of that stream segment (all in CFS). For example, the "7-day 2-year low-flow" is the flow rate, averaged over seven days, that has a 50% chance (i.e. one out of every two years) of being exceeded in any year; the 10-year value has a 10% chance of being exceeded in any year (i.e. one out of every ten years). Low-flow values were calculated using the equations in the USGS Water-Resources Investigations Report 91-4097 "Low-Flow Characteristics of Kentucky Streams" (http://pubs.usgs.gov/wri/wrir_91-4097/). Mean annual streamflow values were calculated using the equation in the USGS Water-Resources Investigations Report 02-4206 "Estimating Mean Annual Streamflow of Rural Streams in Kentucky" (http://ky.water.usgs.gov/pubs/wrir_2002_4206.pdf). Users of the data should be aware of the limitations and accuracy of the equations as explained in those reports and summarized in the metadata for the layer. Drainage area and other streamflow characteristics are available in the 'Stream Data' layer below. This tool works best at a scale less than 1:24,000. After selecting the Identify tool, click on an COLOR stream line to get data for a location of interest.
'Stream Data' contains the following data for streams with orange lines: drainage area (in SQMI), the peak flows Q2 to Q500 (in CFS), and 3 qualifier boxes. An 'X' in the SIZERANGE box means the site is outside the drainage area range of the KY peak flow equations, an 'X' in the URBANAREA box means the site has an upstream impervious area percentage greater than 10 percent and the values given are for rural conditions, and an 'X' in the LAKES box means the site is located in a lake. This tool works best at a scale less than 1:24,000. After selecting the Identify tool, click on an orange stream line to get data for a location of interest.
'Stream Reach Drainage Areas' contains selected data for larger stream reaches (between tributaries). The data reflect two levels, (1) the mean of the local reach watershed and (2) the mean including all upstream or accumulated reaches to that point for the following watershed characteristics: watershed elevation in feet (MEANELEV & ACCMEANELEV), watershed slope in percent (MEANSLOPE & ACCMEANSLOPE), watershed slope in degrees (MEANSLOPEDEG & ACCMEANSLOPEDEG), watershed area in square feet (ACCAREA), watershed area in square miles (SQMI & ACCSQMI), impervious area in percent (PCTIMPERVIOUS & ACCPCTIMPERVIOUS), and the wetness index ( MEANWETNESSINDEX & ACCMEANWETNESSINDEX). After selecting the Identify tool, click on an stream line to get data for the drainage area at a location of interest.This tool works best at a scale between 1:40,000 and 1:100,000. Also, to see the watershed boundaries better, click off the Base Map, Base Imagery, and all Watershed buttons on the legend. Make sure that the check mark is on for this layer in the legend.
'KY discontinued QW Sites' contains the following general information for stream water quality (QW) monitoring sites that have been discontinued: station number (STATION_NO), station name (NAME), drainage area in square miles (DRAIN_AREA), period of record (POR), location in degrees-minutes-seconds (LATITUDE, LONGITUDE), location in decimal degrees (LATDD, LONDD), biological data collected (BIO_ACTIVE), physical data collected (PHY_ACTIVE), sediment data collected (SED_ACTIVE), chemical data collected (CHEM_ACTIVE), and web link to the NWIS data retrieval site (LINK). After selecting the Identify tool, click on a symbol for discontinued QW site to get data for the information at a location of interest.
'KY discontinued SW Sites' contains the following general information for streamflow (SW) monitoring sites that have been discontinued: station number (STATION_NO), station name (NAME), drainage area in square miles (DRAIN_AREA), period of record (POR), location in degrees-minutes-seconds (LATITUDE, LONGITUDE), location in decimal degrees (LATDD, LONDD), continuous record flow data available (FLOW), continuous record stage data available (STAGE), peak discharge data available (PEAK_FLOW), low flow discharge data available (LOW_FLOW), miscellaneous flow measurements available (MISC_FLOW), and web link to the NWIS data retrieval site (LINK). After selecting the Identify tool, click on a symbol for discontinued SW site to get data for the information at a location of interest.
'Nitrogen Phosphorus' contains nitrogen and phosphorus loads in Kentucky streams that have been estimated with the Kentucky SPARROW (SPAtially Referenced Regressions On Watershed Attributes) model. Information on the National SPARROW model is at http://water.usgs.gov/nawqa/sparrow/. All estimates are in kilograms per year for the downstream end of both monitored and non-monitored KY stream reaches (or watersheds). Drainage areas for these reaches are in square kilometers (DRAINAGE_AREA_KM2). Estimates are based on a KY SPARROW model calibrated with data from 40 monitored stations in Kentucky and Tennessee. Reaches for the monitored sites are indicated by the presence of a STATION_ID and STATION_NAME in the data table. Average annual total nitrogen load (AVG_TN_LOAD_KG_PER_YEAR) and average annual total phosphorus load (AVG_TP_LOAD_KG_PER_YEAR) estimates for non-monitored reaches are provided with a LOWER BOUND and UPPER BOUND of the 95% confidence interval (CI) of the model estimate. Results presented here are from an adjusted model. This means that measured data for monitored reaches were used to adjust the model at each monitored reach and thereby improve the accuracy of the estimated nutrient loads for the downstream reaches. Consequently, the model is most accurate immediately downstream of a monitored reach. Conversely, the largest accumulated error is in reaches immediately upstream of a monitored reach. The Nitrogen Phosphorus layer is only visible at resolutions coarser than 1:500,000 scale in order to maintain a statewide perspective and because the stream reach data are derived from the coarser National model. It is most clearly viewed at a resolution coarser than 1:650,000.
3. Activate the layer you desire by clicking on the name of that layer.
4. Left click on the Identify button on the toolbar (the one that is an "I" inside the black circle).
5. Left click on a point of interest, either within a watershed or at a stream location (you may have to click more than once to land on the stream line). The associated data will be displayed in a small table below the map. If more than one line of values appears, it is likely that you are too close to another stream and you may have to reclick or zoom in farther.
Additional Information & Guidance
You will notice in the legend on the left that the so called perennial streams (24K NHD) are the blue lines. The stream data lines are the thicker orange lines. The orange stream data lines start at a minimum a 0.1 square mile drainage area and increase by 0.01 square mile increments. In many cases, the orange lines extend well beyond the NHD blue lines and basically depict the intermittent and ephemeral channel systems determined from the statewide digital topography (the 30-foot DEM). In some cases, though, the NHD blue lines extend above this 0.1 square mile cut off, a result of how these streams were interpreted for conditions when the field work for the original topographic maps were made. More commonly, NHD (blue) and stream data (orange) line segments are concordant and are shown as blue lines with an orange background. Click on the KyMaps tool button to visit other KYGEONET sites.Cautionary Notes
Note that the state map on the browser shows the areas of karst in yellow. At this point in time, this current drainage area tool is based on surface topographic features only and is a very "approximate" estimator of drainage area in karst terrain. Use with caution in karst areas as there are large uncertainties in the underground basin contributions and linkage to work of KGS, KDOW, and USGS related to karst basin delineations needs to be incorporated.See other web links to better understand how you might account for drainage area inconsistantcies in karst areas:
Karst Hydrological Issues at: http://www.water.ky.gov/gw/gwtech/karst/
Karst Atlas of Kentucky & Karst Groundwater Basin Maps at: http://www.uky.edu/KGS/water/research/kaatlas.htmlAlso, use with some caution in urban, mining, and others areas where significant land surface disturbance has occurred. Improvements in karst and other area measurements will be implemented over time. Other hydrologic data will be added to this tool over time.