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Project Work Plan

Department of Interior USGS GE PES

Fiscal Year 2010 Study Work Plan

Study Title: Greater Everglades Hydrology Monitoring Network: Data Mining and Modeling to Separate Human and Natural Hydrologic Dynamics
Study Start Date: 10/01/2004 Study End Date: 9/30/2010
Web Sites:
Location (Subregions, Counties, Park or Refuge): Total System
Funding Source: GE PES
Other Complementary Funding Source(s): none
Funding History: FY05 was the first year of funding for this project
Principal Investigator(s): Paul Conrads
Study Personnel: Paul Conrads, Matthew Petkewich, Andy Caldwell, Stephen Benedict, Mark Lowery, Kenneth Odom, Ed Roehl, and Ruby Daamen
Supporting Organizations: USGS-South Carolina Water Science Center
Associated / Linked Studies: South Florida Surface Water Hydrologic Network for Support of MAP Projects (Higer, Telis, PIs); Water Quality Monitoring and Modeling for the A.R.M. Loxahatchee National Wildlife Refuge (Brandt, Harwell, Waldon, PIs); Estimation of Critical Parameters in Conjunction with Monitoring of the Florida Snail Kite Population (Wiley Kitchens, PI); Freshwater Inflows to Northeastern Florida Bay (Hittle, PI); TIME Model Development (Eric Swain, PI); South Florida Ecosystem History (Willard, PI); Snail Production Assessment 1985-2005; (Darby, PI).

Overview & Objective(s): New technologies in environmental monitoring have made it cost effective to acquire tremendous amounts of hydrologic and water-quality data. Although these data are a valuable resource for understanding environmental systems, often these data are underutilized and/or under interpreted. The monitoring network(s) supported by the Comprehensive Everglades Restoration Plan (CERP) records tremendous amounts of data each day and the data base incorporates millions of data points describing the environmental response of the system to changing conditions. To enhance the evaluation of the CERP data base, there is an immediate need to apply new methodologies to systematically analyze the data set to address critical issues such as detecting change in hydrologic behaviors, water depths at ungaged locations, water-depths and water-quality responses to controlled flow releases, and relative impacts of controlled freshwater releases, tidal dynamics, and meteorological forcing on streamflow, water level, and salinity. There also is a need to integrate longer-term hydrologic data with shorter-term hydrologic data collected for biological resource studies. This study is undertaken as a series of studies (tasks) to demonstrate the efficacy of data mining techniques, including artificial neural network (ANN) models, to evaluate CERP data and address hydrologic issues important to DOI's efforts in South Florida.

The objectives of the studies for FY10 include: (1) multidecadal hindcasting of EDEN stations and evaluation of EDEN and TIME for real-time assessment of change; (2) continued hydrologic support of other PIs including Krabbenhoft and mercury studies; Brandt and the application of the Loxahatchee Empirical Model, and Darby and Kitchens and Snail Kite studies; (3) completion of Coastal Gradient Network Analysis; and, (4) linking paleoecological and hydrologic time series.

Specific Relevance to Major Unanswered Questions and Information Needs Identified: (Page numbers below refer to DOI Science Plan.)

An important part of the USGS mission is to provide scientific information to manage the water resources of the Nation, including the other Agencies of the Department of Interior (DOI). The objectives for this study addresses science needs to support DOI managers in fulfilling their stewardship responsibility as identified in The Science Plan in Support of Ecosystem Restoration, Preservation, and Protection in South Florida (U.S. Department of Interior, 2004). This is consistent with primary USGS activities that include providing knowledge and expertise to assist various levels of government in understanding and solving critical water-resources problems.

The study objectives to develop hindcast hydrologic time series to generate water surface elevation and depth maps and the network analysis of the Coastal Gradient Network are part of the overall objective to support the South Florida Hydrology Monitoring Network and the Monitoring and Assessment Plan (MAP). The MAP was developed as the primary tool to assess the system-wide performance of the CERP by the REstoration, COordination and VERification (RECOVER) program (p. 17, DOI Science Plan). The MAP describes and outlines the monitoring and supporting enhancement of scientific information and technology needed to measure the responses of the South Florida ecosystem to CERP projects.

The study objectives of continued support of the hydrologic and water-quality response models for the Arthur R. Marshall Loxahatchee NWR, continued hydrologic support of mercury and snail kite studies, and the linking of multidecadal hydrologic hindcasts and paleoecological studies meets a stated need in the Science Plan for the "synthesis and integration of data about historic hydrologic and ecological conditions on the refuge" and "research to understand the ecological effects of hydrology and water quality on refuge resources..."(p. 37 and 40, DOI Science Plan). The study objectives will benefit the DOI and other Federal and State Agencies in South Florida by providing data analysis needed by water-resource managers to make decisions concerning the quantity and quality of water resources in the Everglades.

Many of the objectives of the studies supports the Water Conservation Area 3 Decompartmentalization and Sheetflow Enhancement Project (DECOMP) by addressing the science needed for "...additional research to understand the effects of different hydrologic regimes and ecological processes on restoring and maintaining ecosystem function..." (p. 64, DOI Science Plan) and supports ecological studies of impacts of hydrologic change on Everglade snail kite habitat. The study also supports the Combined Structural and Operational Plan project (CSOP) by addressing the needed science for "...refinement of hydrologic targets and operating protocols (p. 63, DOI Science Plan)."

Status: There were four objectives for the first year (FY09) of the Data Mining Study:

  1. Develop application to estimate missing water-level data for EDEN,
  2. Analysis of the Coastal Gradient Network,
  3. Completion of the Loxahatchee Empirical Model, and
  4. Continued support of other Everglades studies.

The first objective has been completed and has been incorporated into the data management process of EDEN. The second objective has been partially met. The majority of the analysis of the Coastal Gradient Network has been completed and needs to be finalized and documented. The third objective has been met with the completion of the Loxahatchee Empirical Model. The most significant support for other Everglades studies of the fourth objective has been the collaboration of linking hydrologic behaviors in WCA3A and methyl mercury production.

Recent Products: Products from FY09 of the study included (1) Open-file Report 2009-1120, "Estimation of Missing Water-Level Data for the Everglades Depth Estimation Network (EDEN)," (2) Loxahatchee Empirical Model (Excel application), (3) Water Environment Federation Technical Exhibition conference proceedings paper and presentation "Maximizing Data-Collection Networks by Using Data-Mining Techniques - Case Studies in the Florida Everglades," and (4) National Conference on Ecosystem Restoration poster presentation "Dealing with Data Realities -Automation of Evaluation of Data Quality and Estimation of Missing Data for the Everglades Depth Estimation Network (EDEN)."

Planned Products: Major products include (1) Scientific Investigation Report on the development and application of the Loxahatchee Empirical Model, (2) Scientific Investigation Report on the analysis of the Coastal Gradient Network, (3) multidecadal hindcasts of WCA3A for EDEN, (4) evaluation of simulation results of EDEN and TIME, and (4) presentations at GEER 2010 on hydrologic support of Everglades studies.


Title of Task 1: EDEN technical support - EDEN and TIME model evaluation, multidecadal hindcasting.
Task Funding: USGS Priority Ecosystems Science
Task Leaders: Paul Conrads
Phone: (803) 750-6140
FAX: (803) 750-6181
Task Status: Active
Task priority: high
Time Frame for Task 1: 2010FY
Task Personnel: Paul Conrads, Stephen Benedict, Andral Caldwell, and Matthew Petkewich

Task Summary and Objectives: The Everglades Depth Estimation Network (EDEN) was established to support the South Florida Hydrology Monitoring Network module of the Comprehensive Everglades Restoration Plan (CERP) and the Monitoring and Assessment Plan (MAP) and Restoration Coordination and Verification Team (RECOVER). The goals of EDEN are to help guide large-scale field operations, integrate hydrologic and biologic responses, and to support the MAP assessments by scientists and principal investigators across disciplines. One objective of EDEN is to relate water-level data at real-time stage gages to ungaged areas using ground elevation data, so that water depths throughout the greater Everglades can be estimated (Telis, 2005: ).

There is interest among PIs and water-resource managers for EDEN to generated water-surface and water-depth maps prior to 2000. The maps would enable analysis of disparate data prior to 2000 with the hydrology of the EDEN maps, using the suite of available EDEN applications. As one moves back in time, the quantity and quality of available data diminishes. An objective of the EDEN hindcasting effort will be to identify period where long-term hydrologic time series will support hindcasting and to hindcast particular conservation areas for generating water-surface elevation maps rather than the entire freshwater EDEN domain.

With the de-compartmentalization of the Everglades, there is a need for monitoring networks for real-time assessment of alteration in flows. Simulation models, such as TIME, can extrapolate in time and space a limited number of monitoring sites to predictions at a denser number of locations. Although TIME has been used for the evaluation of a number of de-compartmentalization scenarios, the use of TIME on a real time or near real-time basis is logistically challenging due to pre- and post-processing of data and simulation runtimes. An alternative approach would be to use near real time EDEN surfaces for real time assessments. In order to use the EDEN results with confidence, an evaluation of the TIME and EDEN simulations need to be evaluated.

Work to be undertaken during the proposal year and a description of the methods and procedures:

For the multidecadal hindcasting for the EDEN network, various approaches will be explored to develope accurate hindcasts. Previously, 2- and 3-stage ANN models were used to hindcast water depths and water level (Conrads and Roehl, 2006; Conrads and Roehl, 2007). In addition, a process model using flows and rainfall will be evaluated.

For the evaluation of EDEN and TIME, stations from the Everglades National Park will be used to compare the output from the two models. Initially, 17 stations from Shark River Slough will be compared on the daily, monthly, and annual time basis. The National Hydrologic Assessment Tool (NATHAT) will be used to generate hydrological indices for the time series from each model to characterize how well each one is able to simulate the frequency, timing, magnitude of hydrologic events. After the evaluating the initial stations, additional stations will be compared.

Specific Task Product(s):

  1. Evaluation of EDEN and TIME results for stations in Shark River Slough (February 2010)
  2. Evaluate additional sites from Everglades National Park (June 2010).

Title of Task 2: Hydrologic Support of other Everglades Studies (Mercury, Snail Kite, Loxahatchee Empirical Model)
Task Funding: USGS Priority Ecosystems Science
Task Leaders: Paul Conrads
Phone: (803) 750-6140
FAX: (803) 750-6181
Task Status: Active
Task priority: High
Time Frame for Task 2: 2010FY
Task Personnel: Paul Conrads, Matthew Petkewich

Task Summary and Objectives: Hydrologic support of three Everglades studies will continue into FY 2010. In FY 2009, a systematic approach to analyzed historical data for periods of different hydrologic behaviors was applied to water level time series in WCA3A proximal to a long-term mercury sampling location. Cummulative Z-scores were computed for 35-year water-level data and plotted versus time. Changes in the slope of the cumulative Z-score indicate changes in hydrologic behaviors. Frequency distributions of water levels for 5 periods were graphed and shifts in the frequency distribution from 1992-2000 to 2001-2007 shows that there was about 0.5 feet shallower after 2000. Results of analysis help explain changes in mercury cycling in WCA3A. The analysis will be documented as a contribution to a journal article on mercury methylation and additional sites will be analyzed in 2010.

The Arthur R. Marshal Loxahatchee National Wildlife Refuge is the last of the soft-water ecological systems in the Everglades. Historically, the ecosystem was driven by precipitation inputs to the system that were low in conductance and nutrients. With controlled releases into the canal that surround the Refuge, the transport of water with higher conductance and nutrient concentration could potentially alter critical ecosystem functions. With potential alteration of flow patterns to accommodate the restoration of the Everglades, the Refuge could be affected not only by changes in the timing and frequency of hydroperiods but by the quality of the water that inundate the Refuge.

Natural resource managers and users face difficult challenges when managing the interactions between natural and man-made systems. At considerable cost, complex mechanistic models based on first principles physical equations are often developed and operated by senior scientists to evaluate options for using a resource while minimizing harm. However, varying technical abilities and financial constraints among different stakeholders effectively restrict access to relevant scientific knowledge and tools. There is a need to provide equal access to the knowledge and tools required for informed decision-making. DSS technology can help meet this need.

There is a long history of collecting hydrologic and water quality data in the Refuge. Data characterizing the hydrology of the system - inflows, outflows, precipitation and water levels have been collected since the 1950's. Data characterizing the water quality of the system, including conductance and phosphorus, has been collected since the late 1970's. To enhance the understanding of the hydrology and water quality of the Refuge, the Lox Empirical Model decision support system (DSS) was developed and built around a suite of empirical hydrologic and water-quality models. Lox Empirical Model's sub models predict how rainfall, ET and flows into and out of into the Refuge impact gage heights at 6 sites, specific conductance at 25 sites, and total phosphorus at 14 sites. The model development and application will be documented in 2010 along with continued support to use the model to evaluate management alternatives for the Refuge.

Previous support of snail kite ecological studies (Kitchens) have included the development of a decision support system that hindcast short-term (less than 3 years) water depth data with long term (greater 15 years) water-level data. The DSS allowed plant ecologist to analyze hydrologic histories and vegetation data to better understand the linkage between hydrology and vegetation progression of nesting and foraging habitat of the snail kites. The apple snail is a critical aspect of the snail kite life cycle. A new study (Darby, January 2010) will document the production of the apple snail from 1985 to 2005. Many of the tools developed for the earlier studies will be of utility to explore different hydrologic behaviors and apple snail production.

Work to be undertaken during the proposal year and a description of the methods and procedures:

Specific Task Product(s):

  1. Analysis of hydrologic behaviors at additional mercury sampling sites.
  2. Documentation of shifts in hydrologic behavior at mercury sampling site. Documentation will be contribution to a journal article.
  3. Scientific Investigation Report on the development and the application of the Loxahatchee Empirical Model.

Title of Task 3: Coastal Gradient Network Analysis
Task Funding: USGS Priority Ecosystems Science
Task Leaders: Paul Conrads
Phone: (803) 750-6140
FAX: (803) 750-6181
Task Status: Active
Task priority: high
Time Frame for Task 3: 2010FY
Task Personnel: Paul Conrads, Kenneth Odom

Task Summary and Objectives: To analyze and understand the interaction of natural and societal systems, data-collection networks are needed to quantify anthropogenic influences on natural systems. The ideal data collection network would provide a spatially and temporally extensive record of the interactions between natural and societal systems. With funding and logistical challenges in maintaining gaging networks, there is a need to evaluate networks to understand the uniqueness of the information from the network.

Time series cluster techniques have been developed and used grouping hydrologic time series of similar behaviors. The technique was used to select indexing sites for hindcasting 25 EDEN sites. The water level, salinity (specific conductance), and discharge time series data for the Coastal Gradient Network was analyzed using by using a K-mean clustering routine. Cross-correlation matrix was generated for the stations with the same parameters. The Pearson coefficient in the matrix is a measure of the correlation between each station in the network. The clustering routine computes the average distance between the vector (Pearson coefficient) and the mean value of a cluster. The optimal number of clusters is determined by maximizing the reduction of the distance measure with groups (RMSE) and minimizing the number of groups.

After the initial clustering of the data by groups of similar behaviors, the technique is then repeated on each sub-group to determine and rank the uniqueness of each gage/parameter within the group. This work is being done in collaboration with Kenneth Odom, Alabama Water Science Center. Kenneth is applying principle components to a subset of the data. Results from the two approaches will be compared and contrasted.

Work to be undertaken during the proposal year and a description of the methods and procedures:

The majority of the analysis was completed in FY09 and presented to the Coastal Gradient Team (Patino, Zuckers, and Woods) in the fall of 2009. The analysis will be finalized this proposal year and documented in a Scientific Investigations Report.

Specific Task Product(s):

  1. Document analysis in Scientific Investigations Report

Title of Task 4: Paleocological and hydrological timeseries linkgage
Task Funding: USGS Priority Ecosystems Science
Task Leaders: Paul Conrads
Phone: (803) 750-6140
FAX: (803) 750-6181
Task Status: Active (first year)
Task priority: high
Time Frame for Task 4: 2010FY
Task Personnel: Paul Conrads, Stephen Benedict, Matthew Petkewich, and Ed Roehl

Task Summary and Objectives: There is an immediate need to be able to link changes in hydrology to changes in tree island and ridge and slough landscapes in Water Conservation Areas (WCA) 3A, 3B, and Shark River Slough and to be able to evaluate alternative hydraulic operations on the performance these landscape features. Landscape feature change due to hydrologic dynamics has many causes that act on different time scales and are both anthropogenic and non-anthropogenic in origin. They include non-anthropogenic forces such as hurricanes and fire that can bring rapid change, and slower acting forces that include periods of extended high temperatures and drought. Possible anthropogenic causes include the installation of structures that impede natural sheetflow and hydraulic management practices within compartments.

Intact soil cores from Everglades' marshes provide valuable information on historical trends in ridge and slough peat dynamics, and changes in vegetation, fire frequency, and hydrologic conditions. Willard and other have paleoecological evidence from over 60 sites throughout the region that provide the information on landscape, vegetation, and hydrologic histories. Prevailing hydrologic conditions at each core location and point in time can be estimated from the relative concentrations of hyrolologically sensitive vegetation species in the peat. While the soil core analyses will cover the period back to the mid 1800's in some instances the interval between soil core analyses will be up to a decade.

It is believed that the temporally sparse core data, and the potentially weak description of causal hydrology to be obtained from the core analyses, could be problematic for greatly improving our understanding of and modeling the relationships between hydrology changes and landscape feature change. Fortunately, much more data of many types is available.

  • Water-level and water-depth time series - from locations that date back to the early 1940's with increasing areal coverage increasing to the current day.
  • Meterological time series - from multiple locations that can provide direct indications of storms and hurricanes, and prolonged periods of heat and drought. It is certain that major meteorological events can be identified from the available data, going back decades.
  • Groundwater-levels and pumping
  • Records of compartment development and management activity
  • Compartment inflow and outflow time series
  • Fire event records - fire events would likely coincide with drought conditions.

The availability of continuous multi-decadal time series data suggests that changes in water-level variability over time could be an excellent indicator for identifying events and longer-term trends that portend landscape feature change, and that other time series will help identify the causes of change. The project proposed here will provide cause-effect information about hydrologic change on a fine temporal scale over 6 decades. This information will allow all of the researchers to test their findings more comprehensively than would otherwise be possible.

Work to be undertaken during the proposal year and a description of the methods and procedures:

In FY 2010, we will begin exploratory work linking landscape and hydrology changes in various locations in the Everglades. The vegetation and landscape of the Everglades is an expression to the hydrologic history of area. The objective of this study is to develop methodologies and approaches for linking hydrologic dynamics with changes in vegetation and landscape. Much of the study will be exploring various ways of integrating and analyzing the available data. Clustering is a way of grouping data by similar response. The challenge to this study is that the areas of interest (hydrology, vegetation, and landscape) changes on various time scales. The data representing these processes also are collected on various time scales - from hourly to annual sampling intervals.

  1. Develop historical database - that integrates hydrologic, meteorological and other time series data, with existing tree island, ridge and slough, and paleo-ecological change information for 3-5 sites.
  2. Data mining - the primary analysis methods will be signal processing, time series clustering, and non-linear, multivariate correlation functions using artificial neural networks (ANNs). Sub-tasks to be completed include:
    1. Identify periods of rapid and long-term hydrologic change
    2. Identify causes of hydrologic change - using meteorological, fire, compartment inflows and outflows, and other data.
    3. Develop timeline of hydrologic change and causes
    4. Hindcast hydrologic time series - to produce a more temporally and spatially comprehensive historical record using ANNs.
    5. Explore approaches to characterizing hydrologic periods - including measures of episodic events, long-term conditions, and lengths of hydrologic periods. Differences in water-level characteristics also can be analyzed by determining how hydroecological indices change over time. Where they exist, historical hydrologic data reflective of overland flow will be incorporated into the historical data set. Because direct historical measurements of overland flow are very limited, we will develop and evaluate the utility of indirect hydrologic indicators of overland flow/sheetlow for use in the landscape analysis.
    6. Correlate hydrologic characterization (sub-task E) with quantification of landscape change. Existing data from soil core analyses will be used to link the hindcast hydrology to existing paleo-ecological age models These data sets and hindcasts of water levels proximal to areas of changes in tree islands will be used to evaluate various approaches linking hydrology and landscape change.

Specific Task Product(s):

  1. Compiled historical database of time series and other data.
  2. Timeline of hydrologic changes and their causes.
  3. Correlation of hydrologic indices and landscape change.

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