Title: Monitoring Drought in the
1Monitoring Drought in the 21st Century A
Resolution Revolution
Mark Svoboda National Drought Mitigation
Center International Drought Information
Center University of Nebraska-Lincoln
2Why Monitor Drought?
- Drought is a Normal Part of the Climatic Cycle
- Drought Impacts are Significant Widespread
- Many Economic Sectors Affected
- Drought is Expensive
- Since 1980, major droughts and heat waves within
the U.S. alone have resulted in costs exceeding
100 billion dollars (NOAA/NCDC) - Average annual losses 6-8 billion (FEMA 95)
3An integrated climate monitoring system needs to
- be comprehensive in scope (coupling climate, soil
and water data) - incorporate local and regional scale data
- use the best available (multiple) indices and
triggering tools - link index values or thresholds to impacts
- be flexible, incorporating the needs of users
4The Importance of a Drought EWS
- allows for early drought detection
- allows for proactive (mitigation) and reactive
(emergency) responses - triggers actions within a drought plan
- Bottom line?provides information for decision
support
5Components of a Drought EWS
- timely data and timely acquisition
- synthesis/analysis of data used to trigger set
actions within a plan - efficient dissemination or delivery system (WWW,
media, extension)
6Importance of Drought Indices
- Simplify complex relationships and provide a good
communication tool for diverse audiences - Quantitative assessment of anomalous climatic
conditions - Intensity
- Duration
- Spatial extent
- Historical reference (probability of recurrence)
- Planning and design applications
7Triggers thresholds determining specific, timely
actions by decision makers. Link impacts to index
or indicator values.
Triggers need to be
- appropriate
- consistent with impacts
- adaptable
8Considerations for Selecting a Specific Trigger
or Index
- Is the information readily available?
- Is the information likely to remain available
over time? - Can an index/trigger be calculated in a timely
manner? - Can the index/trigger be meaningfully correlated
to actual conditions (impacts)?
9Approaches to Drought Monitoring (assessment)
- Single index or parameter
- Multiple indices or parameters
- Composite index
10The U.S. Drought Monitor
Since 1999, NOAA (CPC and NCDC), USDA, and the
NDMC have produced a composite drought map -- the
U.S. Drought Monitor -- each week with input from
numerous federal and non-federal agencies
11U.S. Drought Monitor Map
Drought Intensity Categories
D0 Abnormally Dry
D1 Drought Moderate
D2 Drought Severe
D3 Drought Extreme
D4 Drought Exceptional
12U.S. Drought Monitor
- Several key and ancillary indicators
- Attempts to capture conditions across
widespectrum of drought conditions -
- Must Address
- No single definitionof drought
- Integrates manyindicators
- Now creating in
- ARC GIS
13http//drought.unl.edu/dm
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15Continental-Scale Indicators
- Standardizing Period 1951-2001 (for PCTPCP,
SPI, PDI) - Guidance for drought category boundaries across
international borders
16Is There a Need for a Water Resources Monitor?
- Mark Svoboda
- National Drought Mitigation Center
With Contributions From Harry Lins, USGS Phil
Pasteris, USDA/NRCS Frank Richards, NOAA
17Water Monitor Concept
- A proposed partnership between the USGS, NOAA,
USDA and the NDMC - Idea hatched in spring 2003 as a potential answer
to the debate of 1 vs. 2 DM maps (short- and
long-term drought) and as a better tool for the
DM authors - A consolidation of indices and hydrological
indicators by basin or hydrological unit - The Water Resources Monitor portal (maintained
by USGS) would provide for a general hydro
assessment of water resources in the U.S. to
compliment the Drought Monitor
18Water Resources Monitor
19Water Resources Monitor
20BASIN WATER INDEX (BWI)
- Components precipitation (antecedent precip
index (API) used), snowpack, streamflow,
reservoir storage, well observations - Based on hydrological units
- National application potential using a modified
SWSI approach - Flexible to include any combination of collected
variables - Overall index values can aid DM authors or other
users in monitoring drought - Non-exceedance values can be computed for the
individual components or for the aggregate
variable
21Basin Water Index Provides for a
nationwide (potentially) water availability index
that minimizes the documented limitations of the
SWSI (Still under development)
Water and Climate Center
22National Agricultural Decision Support System
- Allows for weekly table/map output of the
- SPI, PDSI and Newhall values
- 1948-present (base 61-90 for distribution)
- HPRCC/ACIS SHEF formatted real-time data from
COOP and first order sites
23http//nadss.unl.edu
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28Standardized Precipitation Index (SPI) by
Climate Division (above), and by 0.25º grid
(below)
U.S. Department of the Interior U.S. Geological
Survey EROS Data Center
29Assessing and Monitoring Drought with Climate,
Satellite, and Other Geophysical Data Sets Using
Data Mining Techniques
- T. Tadesse, J. Brown, and M. Hayes
- National Drought Mitigation Center, University
of Nebraska-Lincoln - USGS/EROS Data Center, Sioux Falls, SD
30Integrating Satellite and Climate Data
- Percent of Average Seasonal Greenness highlights
areas with lower than average vegetation
condition - Can be caused by drought, flooding, late
greennup, land cover conversion, etc. - Climate-based drought indicators enable
interpretation of the satellite data anomalies
31Methodology
Model Input
VegDRI (Vegetation Drought Response Index
Avg Seasonal Greenness
32Data Mining
- Data mining is a method that brings techniques
from machine learning, pattern recognition,
statistics, databases, and visualization together
to address the issue of information extraction
from large databases (Cabena et al., 1998) - Data mining tools can answer questions that
traditionally were too time-consuming to resolve - high computing, fast data access, large storage
of data - Search databases for hidden patterns and find
predictive information that experts may miss
because it lies outside their expectations
(Thearling, 2001)
33Prototype Veg-DRI May 30, 2002
34Prototype Veg-DRI July 25, 2002
35Prototype Veg-DRI September 5, 2002
36July 11, 2002
Drought Monitor July 9, 2002
37A County Story
Hand County, South Dakota
38Hand County, SD
- Total area 3,705 km2 (9 million acres)
- Top Five Commodities (from 1997 Ag census)
- Cattle and calves
- Wheat
- Corn (for grain)
- All other grains
- Hogs and pigs
39Land Cover (from National Land Cover
Database) Pink Row Crops Burgundy Small
Grains Tan Grassland Yellow Pasture/Hay
40Hand County, SD
May 30, 2002
July 25, 2002
September 5, 2002
47 of county is normal 53 of county is in
drought
41Hand County, SD
July 25, 2002
Land Cover
168,000 acres of grassland impacted by
drought 213,000 acres of row crops impacted by
drought
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43Conclusion
- Better resolution (1 km2 pixel) drought response
maps were produced as opposed to drought maps
that were traditionally made at the county and
climate division level - Better information on vegetation stress
particularly for pasture and rangelands - Integrates both satellite and climate information
at the same time - Rule-based models can be used in predicting the
agricultural condition of drought up to six weeks
in advance with relatively higher accuracy - Gives prospects of timely information (near-real
time web-delivery) for decision makers - Caveats should be used as complementary
information until it is fully operational
44Future Work
- Progress
- Web-based delivery of near real-time data and
maps (http//gisdata.usgs.net/website/Drought_Moni
toring/viewer.asp) - Challenges
- Extending from Central Plains to conterminous
U.S. - Transitioning from research and development stage
to operational system
45General Views on Drought Forecasting
- Easiest during strong climate fluctuations (La
Nina, El Nino, etc.) - A combination of art and science, needing to
skillfully combine short-term and long-term
signals - Forecasts are slowly improving as they gain
experience in using both dynamic and statistical
forecasts as well as climatology - Much more research needed to determine how the
atmosphere, oceans, and continents talk to each
other
46CPC Was Among the First to Produce Seasonal
Drought Outlooks
(from Climate Prediction Center)
47For the CPC Seasonal Drought Outlooks.
- CPC uses historical information (ENSO composites,
natural and constructed analogues, drought
probabilities) to assess the odds of drought
continuing or dissipating - Also incorporate forecast information for all
appropriate time periods (short, medium, and
long-range) and consider the evolution of
hemispheric circulation patterns
48Climate Indicators that Correlate with U.S.
Drought
- El Niño/La Niña
- PDO
- Solar Cycle
- Arctic Oscillation
- Pacific Warm Pool SSTs
- NH and Global Temperatures
49Simplified Forecast Procedures
- Start out with Drought Monitor D1 areas
- Forecast persist or intensify where seasonal
outlook shows below-normal precipitation - Forecast improvement where seasonal outlook shows
above-normal precipitation - Use Palmer Drought projections, analogues,
composites, and other tools where seasonal
outlook shows equal chances
50ENSO Composites
Constructed Analogue Soil Model
Palmer Drought Projections
Medium-Range Forecast
51Future Drought Monitoring Challenges
- Maintain the momentum of the current Resolution
Revolution - ACIS (Mesonets)
- NOAA/USGS gridded mapping/COOP Modernization
- Satellite/Radar
- NADSS
- USGS
- Others
- Develop a comprehensive water resources
monitoring tool (The Water Resources Monitor??) - Enhancing our nations observed soil moisture
networks (SCAN or Mesonet operated)
52Future Drought Monitoring Challenges
- Impact collection/reporting tools
- Improved drought prediction
- Robust IMS/GIS query/analysis potential for
Drought Monitor and other products - Research, research, research
53Critical Observations
1) No single parameter is used solely in
determining appropriate actions 2) Instead,
different thresholds from different combinations
of inputs is the best way to approach monitoring
and triggers 3) Decision making (or triggers)
based on quantitative values are supported
favorably and are better understood
54http//drought.unl.edu
55Questions? Email me at msvoboda2_at_unl.edu Or
call (402) 472-8238
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57Potential Monitoring System Products and Reports
- Historical analysis (climatology, impacts,
magnitude, frequency) - Operational assessment (coop network data, SPI
and other indices, automated networks, satellite
and soil moisture data) - Predictions/Projections (SPI and other indices,
soil moisture, streamflow, seasonal forecasts,
SSTs)
58Why the Recent Interest in Drought in the U.S.?
- Single and multi-year severe droughts
- intensity and duration
- western and eastern U.S.
- Spatial extent40 to 50 of U.S. in 2002-03
- Complexity of impacts ? Vulnerability
- Agriculture, energy, transportation, urban water
supply, recreation/tourism, fires, environmental,
social - Conflicts between water users
- Water restrictions (agricultural and urban)
- Trend toward drought mitigation planning
- Media coverage
59Recent Drought Losses in the U.S.
1988 39.2 billion nationwide 1993 1 billion
across the Southeast 1996 10 billion across
the Southwest 1998 6-8 billion across the
South 1999 1 billion along the East
Coast 2000 1 billion each in Nebraska,
Oklahoma, Texas, and Georgia 2002
gt20 billion nationwide?? 2003 billion ????
Average annual losses 6-8 billion (FEMA)
60Components of a Drought Plan
- monitoring, early warning, and prediction
- risk and impact assessment
- mitigation and response
61Questions addressed by monitoring
- Analyze recent eventshow did we get here?
- Place current situation in a historical
contexthow rare is this event? - What is the forecast and how reliable is it?
- What would it take to end the drought event?
- How can we communicate this information to
decision makers to encourage positive action?
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63Key Variables For Monitoring Drought
- climate data
- soil moisture
- stream flow
- ground water
- reservoir and lake levels
- snow pack
- short, medium, and long range forecasts
- vegetation health/stress and fire danger
64Indicators for The West
65Original Objectives
- Fujita-like scale
- NOT a forecast!
- Identify impacts (A, H)
- Assessment of current conditions
- Incorporate local expert input
- Be as objective as possible
66Drought Severity Classifications
Indices used primarily during the snow season
and in the West include the River Basin Snow
Water Content, River Basin Average Precipitation
and SWSI
67Objective Blends
Useful for showing situations and areas having
similar trends or opposite trends in moisture
conditions
68Objective Blends
- Short-Term Blend
- 35 Palmer Z Index
- 25 3-Month Precip.
- 20 1-Month Precip.
- 13 CPC Soil Model
- 7 Palmer Drought
- Index
69Objective Blends
- Long-Term Blend
- 25 Palmer Hydrological Index
- 20 24-Month Precip.
- 20 12-Month Precip.
- 15 6-Month Precip.
- 10 60-Month Precip.
- 10 CPC Soil Model
70A Possible Approach
- Start w/ streamflow data
- Supplement as best as possible w/ other data
- Base analysis on HUCs
- Use GIS/IMS as key tools
- Map depicts where impact occurs?
- Value added from experts/subjective assessment
and interpretation of the objective factors - Maintain web site and open listserver like the DM
71Next Steps
- Pitch importance/need for an integrated water
resource assessment portal - Develop prototype product/website by January 2004
- Get input from you!
72The Importance of Local Expert Input
- The National Centers can produce a variety of
input indicator products(e.g., CPC station dot
map) - These give us The Big Picture
73The Importance of Local Expert Input
- The U.S. Drought Monitor Team Relies on Field
Observation Feedback from the Local Experts for
Impacts Information Ground Truth - Listserver (140-150 Participants 2/3 Federal,
1/3 State/Univ.)
Local NWS USDA/NRCS Offices State Climate
Offices State Drought Task Forces Regional
Climate Centers
Midwest Regional Climate Center
74The Importance of Local Expert Input
High PlainsRegionalClimate Center
75The Importance of Local Expert Input
Colorado Climate Center
Western Regional Climate Center
76The Importance of Local Expert Input
Montana StateDrought Advisory Committee
Oregon State Climatologist Office
77 Questions
- Is there a need for a hydro-oriented companion to
the Drought Monitor? - Whos the audience?
- Whats needed to make it happen?
78Observed real-time data are essential
- for timely drought assessments (real-time and
historical) - for increased spatial and temporal resolution
- as input for generating many climate
products/forecasts - ground truthing of soil moisture (and other)
models - ground truthing of radar precipitation
estimates - getting information to decision makers when they
need it.i.e. yesterday! - filling in data sparse areas
-
-
79Mesonet Sites Approx. 1,000 in the U.S.
80Next Steps
- Incorporate elevation factor (SNOTEL)
- Integrate TD3206 data for pre-1948 analysis
- Incorporate projected SPI maps based on
- .80/.50/.20 for decision makers
- Implement Pearson III in the code
- Extend out to 104 weeks (2 years)
- More exposure analysis research
81Why should we integrate satellite and climate
data ?
- Percent of Average Seasonal Greenness highlights
areas with lower than average vegetation
condition - Vegetation stress can be caused by drought,
flooding, late Greenup, land cover conversion,
etc. - Climate-based drought indicators will enable
interpretation of the satellite data anomalies - Geophysical parameters such as land cover types
help identify areas with vegetation stress due to
drought - Data mining techniques used to create a model
- Better drought impact map can be produced to
monitor drought
82Experimental Results
- The total of 224 stations in Nebraska and South
Dakota were used - Cubist data mining software was used to generate
a rule-based model - Data Period 1989 to 2002 (14 years)
- Climatic variables bi-weekly SPI and PDSI
- Satellite geophysical variables
- percent of irrigated areas
- ecological type
- land cover type
- satellite-derived start of the vegetation season
- available water capacity of the soil
- satellite-derived percent of vegetation
83What We Need for Better Forecasts
- Better depiction of current drought areas through
improved monitoring capabilities - More accurate forecasts of temperature and
precipitation, especially for seasonal periods - Better ways to incorporate forecasts of
temperature and rainfall into forecasts of
drought indices (Palmer, soil moisture,
streamflows) - Greater understanding of surface-air feedback
processes through statistical and dynamic
modeling improvements - Better ways to depict the probabilities of
drought worsening or improving
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88Observational/Data Requirements
- Primary
- surface water
- reservoir
- groundwater
- Others
- snow
- soil moisture
- water supply forecasts
- PRISM to address elevation