Santee Experimental Forest, Watershed 77 Daily Mean and Total Flow Data, 2003-2017.

Metadata:

Identification_Information
Data_Quality_Information
Entity_and_Attribute_Information
Metadata_Reference_Information

Identification_Information:

Citation:

Citation_Information:

Originator: Amatya, Devendra M. and Trettin, Carl C.
Publication_Date: 2018
Title:
Geospatial_Data_Presentation_Form: database

Description:

Abstract:: This data product contains daily mean flow rates (liters per second) and total daily flow (cubic meters) measured at the Watershed 77 weir on the Santee Experimental Forest near Cordesville, SC from 2003 to 2017. Watershed 77 is a 155 ha first-order treatment watershed that was established in 1963 and became part of a paired watershed system (Watershed 80 was established in 1968 as the control watershed). Elevation ranges from 6 to 10 meters above sea level, and average watershed slope is 3%. The main stream channel is approximately 1260 meters long, and stage is monitored at the watershed outlet using a compound v-notch weir made of metal and concrete.

The predominant forest cover types on Watershed 77 are pine and mixed hardwoods. About 11 % of the watershed is covered by wetlands, comprising bottomland hardwoods and wet pine flats. The major treatments imposed on the watershed over its history have been forest thinning and prescribed fire. Watershed 77 also suffered major damage during Hurricane Hugo in September 1989, as did the control Watershed 80.
Purpose:: The purpose of Watershed 77 when established in 1963 was to provide a site for research on understanding runoff and evapotranspiration processes and the water balance. Since then research has been conducted on the effects of management treatments such as thinning and prescribed burns (taking place since 1976) on the hydrology, water quality, carbon dynamics, soils and vegetation of low gradient, poorly drained forested watersheds in the SC Coastal Plain.

Time_Period_of_Content:

Time_Period_Information:

Range_of_Dates/Times:

Beginning_Date: 2003
Ending_Date: 2017

Currentness_Reference:

ground condition

Status:

Progress: In work
Maintenance_and_Update_Frequency: As needed

Spatial_Domain:

Description_of_Geographic_Extent:

The geographic area covered by the dataset is that defined by the boundary of Watershed 77 in the Santee Experimental Forest.

Bounding_Coordinates:

West_Bounding_Coordinate: -79.78153
East_Bounding_Coordinate: -79.76300
North_Bounding_Coordinate: 33.15007
South_Bounding_Coordinate: 33.13284

Keywords:

Theme:

Theme_Keyword_Thesaurus: None
Theme_Keyword: Forested wetlands
Theme_Keyword: Poorly drained soils
Theme_Keyword: Outflow (runoff)

Place:

Place_Keyword_Thesaurus: None
Place_Keyword: South Carolina
Place_Keyword: Coastal Plain
Place_Keyword: Santee Experimental Forest
Place_Keyword: Watershed 77

Access_Constraints: None

Use_Constraints:

These data were collected by USDA Forest Service researchers. In order to use the data in a publication, presentation or other research product you must agree to acknowledge its source. Please use the reference below when citing this work:

(Data name) courtesy of the USDA Forest Service Center for Forested Wetlands Research.

The following statement may be added after an acknowledgement or credit:

The USDA Forest Service Center for Forested Wetlands Research homepage is http://www.srs.fs.usda.gov/charleston/.

Data_Quality_Information:

Attribute_Accuracy:

Attribute_Accuracy_Report:: The Teledyne-ISCO 4210 flowmeter with ultrasonic sensor (which replaced a 3210 unit in August 2002) measured stage with an accuracy of 0.01 foot. A staff gauge was mounted on the face of the blockhouse to allow direct comparison of stage data to manual readings. SAS and Microsoft Excel software were used to calculate 10-minute and daily mean flow rates, respectively.

4210 stage data from 10/24/08 18:30 to 10/25/08 17:00 (during an extremely large flow event) were predicted using data from a GL400 backup logger/pressure transducer and the following regression equation:

ISCO 4210 = GL400*0.97 - 1.42 (R2 = 0.99)

This equation was derived by regressing 4210 stage data on GL400 stage data for the remainder of the month of October 2008.

Extreme rainfall event on October 3-4, 2015 (and also large amounts of rain on the days before and after) led to record flow levels on the Santee Experimental Forest watersheds. The ultrasonic sensor was briefly submerged during this event, but data from a backup GL400 logger and pressure transducer was available to help predict the missing stage values. Data from 10/1/15 0:00 through 10/3/15 21:00 and then 10/5/15 4:00 through 10/9/15 21:00 were used to generate the following regression equation for October 3-4:

ISCO 4210 = GL400*1.01 - 1.45 (R2 = 0.99)

Stage values around the peak of the highest flows exceeded the earlier established range of the stage-discharge equation for the WS 77 weir (0 to 4.26 feet above the v-notch), and there was also some flow escaping around the weir through an opening in one of the side weir walls. Accurate flow values during these periods were therefore not available and were assigned the "NULL" code.

Hurricane Matthew October 7-8, 2016 caused very high flow levels on the Santee Experimental Forest. The ultrasonic sensor was briefly submerged during this event, but data from a backup GL500 logger and pressure transducer was available to help predict the missing stage values. Data from 10/7/16 4:30 to 10/8/16 1:00 was used to generate the following regression equation for use in estimating stage values during the rising limb of the event:

ISCO 4210 = GL500*0.97 - 1.19 (R2 = 0.99)

Data from 10/8/16 14:30 to 10/11/16 8:00 was used to generate the following regression equation for use in estimating stage values during the falling limb:

ISCO 4210 = GL500*0.99 - 1.22 (R2 = 0.99)

Stage values around the peak of the highest flows exceeded the range of the stage-discharge equation for the WS 77 weir, and there was also some flow around the weir through an opening in one of the side weir walls.

Logical_Consistency_Report:

Visual inspection and comparison with flow data from other SEF flow gauging stations (as well as daily rainfall data) were used to expose anomalous data.

The measurement interval changed from 10 minutes to 15 minutes (and then back again) between 2/20/04 0:00 and 6/14/04 14:00.

Completeness_Report:

No reliable flow data is available for Watershed 77 from 12/18/00 through 2/20/03. However, South Carolina was experiencing a severe drought during much of this period (SC DNR declared that the drought had ended in Berkeley County in November 2002) and there was little or no flow at the gauging station during the drought. Since then there have been brief periods of missing data, largely as a result of equipment failures.

Lineage:

Methodology:

Methodology_Type: Field
Methodology_Description:: A Teledyne-ISCO 4210 flowmeter with ultrasonic sensor was installed on 8/5/02 (replacing a 3210 unit), but it was only programmed to record calculated flow rates (not stage) on a 10-minute interval. This programming was corrected on 2/20/03 so that the 4210 recorded 10-minute stage levels. The 10-minute stage data was downloaded directly to a computer in the field using Flowlink 4 software. The calibration of the ultrasonic sensor was checked regularly against the level of water above or below the v-notch in the weir. If the readings differed by 0.01 foot or more, the 4210 was recalibrated.

Trainum Brothers Co. installed a new wooden platform and safety railing at the site on 6/13/17.

Process_Step:

Process_Description:: Downloaded stage data were post-processed (removing spurious data, such as download artifacts) and prepared for runs with SAS software to generate 10-minute flow rates using the established stage-discharge relationship for the weir.

Daily total flow was calculated in Microsoft Excel spreadsheets by averaging flow rates over the individual recording intervals, multiplying the average rate by the appropriate time factor for the interval and then summing interval flows for each day. Values in liters were then converted to cubic meters.

4210 stage data from 10/24/08 18:30 to 10/25/08 17:00 (during an extremely large flow event) were predicted using data from a GL400 backup logger/pressure transducer and the following regression equation:

ISCO 4210 = GL400*0.97 - 1.42 (R2 = 0.99)

This equation was derived by regressing 4210 stage data on GL400 stage data for the remainder of the month of October 2008.

Extreme rainfall event on October 3-4, 2015 (and also large amounts of rain on the days before and after) led to record flow levels on the Santee Experimental Forest watersheds. The ultrasonic sensor was briefly submerged during this event, but data from a backup GL400 logger and pressure transducer was available to help predict the missing stage values. Data from 10/1/15 0:00 through 10/3/15 21:00 and then 10/5/15 4:00 through 10/9/15 21:00 were used to generate the following regression equation for October 3-4:

ISCO 4210 = GL400*1.01 - 1.45 (R2 = 0.99)

Stage values around the peak of the highest flows exceeded the earlier established range of the stage-discharge equation for the WS 77 weir (0 to 4.26 feet above the v-notch), and there was also some flow escaping around the weir through an opening in one of the side weir walls. Accurate flow values during these periods were therefore not available and were assigned the "NULL" code.

Hurricane Matthew October 7-8, 2016 caused very high flow levels on the Santee Experimental Forest. The ultrasonic sensor was briefly submerged during this event, but data from a backup GL500 logger and pressure transducer was available to help predict the missing stage values. Data from 10/7/16 4:30 to 10/8/16 1:00 was used to generate the following regression equation for use in estimating stage values during the rising limb of the event:

ISCO 4210 = GL500*0.97 - 1.19 (R2 = 0.99)

Data from 10/8/16 14:30 to 10/11/16 8:00 was used to generate the following regression equation for use in estimating stage values during the falling limb:

ISCO 4210 = GL500*0.99 - 1.22 (R2 = 0.99)

Stage values around the peak of the highest flows exceeded the range of the stage-discharge equation for the WS 77 weir, and there was also some flow around the weir through an opening in one of the side weir walls.
Process_Date: Unknown

Entity_and_Attribute_Information:

Overview_Description:

Entity_and_Attribute_Overview:: Variables included in the datasets WS77_dailyflow_2003_to_2007_rev3.xlsx, WS77_dailyflow_2008_to_2011.xlsx, WS77_dailyflow_2012.xlsx, WS77_dailyflow_2013.xlsx, WS77_dailyflow_2014.xlsx, WS77_dailyflow_2015.xlsx, WS77_dailyflow_2016.xlsx and WS77_dailyflow_2017.xlsx:

Location = watershed name (WS77 = Watershed 77);
Instr_ID = gauging station name (Weir77 = water level recorder used in conjunction with WS77 weir);
Date_ = date associated with stage data (format MM/DD/YYYY);
Avg_FlowRa = daily mean flow rate, in L/sec; and
DailyFlow_ = daily total flow, in cubic meters.

All missing data were originally assigned the value "-9999"; during database development this code was changed to "null"
Entity_and_Attribute_Detail_Citation:: None

Metadata_Reference_Information:

Metadata_Date: 20180625

Metadata_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: USDA Forest Service, Southern Research Station, Center for Forested Wetlands Research
Contact_Person: Andy Harrison

Contact_Position: Hydrology Technician

Contact_Address:

Address_Type: mailing and physical
Address: 3734 Hwy 402
City: Cordesville
State_or_Province: SC
Postal_Code: 29434
Country: USA

Contact_Voice_Telephone: 843 336-5603

Metadata_Standard_Name: FGDC Biological Data Profile of the Content Standard for Digital Geospatial Metadata

Metadata_Standard_Version: FGDC-STD-001.1-1999