Operational Drought Monitoring and Forecasting at the USDANRCS
- Slides: 48
Operational Drought Monitoring and Forecasting at the USDA-NRCS Tom Pagano Tom. Pagano@por. usda. gov 503 414 3010
Monitoring networks Data products Seasonal forecasts Soil moisture Challenges Frontiers
Monitoring networks
1906 2005 Manual Snow Surveys Metal tube inserted into snow and weighed to measure water content. +300, 000 snow course measurements as of June 2008
Snotel (SNOw TELemetry) network Automated, remote stations Primary variables: Snow water Precipitation Temperature Also: Snow depth Soil moisture SNOTEL and Snow course records often spliced together
Number of sites Snowcourse (solid) and SNOTEL (hashed) active station installation dates Active year
Soil climate analysis network (SCAN) Soil moisture/energy balance emphasis Short period of record (some from 1990 s) Data available but few products
Manual snow-course SNOTEL SCAN
Data products
Time series charts
CSV flat files Google Earth
Forecast products
Location Forecasts are coordinated with the National Weather Service (NWS). Both agencies publish identical numbers.
Location Historical Average Time Period Forecasts are coordinated with the National Weather Service (NWS). Both agencies publish identical numbers.
Historical Average Location Time Period Error Bounds “The” Forecast Water Volume Forecasts are coordinated with the National Weather Service (NWS). Both agencies publish identical numbers.
Seasonal water supply volume forecasts (available in a variety of formats) NRCS formats:
Seasonal water supply volume forecasts (available in a variety of formats) NRCS formats:
Basic Forecasting Methods Statistical regression Apr-Jul streamflow % avg S Fork Rio Grande, Colo May 1 snowpack % avg
Basic Forecasting Methods Statistical regression Simulation modeling S Fork Rio Grande, Colo Apr-Jul streamflow % avg Snow Rainfall Heat Snow pack Soil water May 1 snowpack % avg Runoff
Principal Components Regression (Garen 1992) Prevents compensating variables. Filters “noise”.
Principal Components Regression (Garen 1992) Prevents compensating variables. Filters “noise”. Z-Score Regression (Pagano 2004) Prevents compensating variables. Aggregates like predictors, emphasizing best ones. Does not require serial completeness. Relative contribution of predictors
Daily forecast updates Existing seasonal forecasts issues once per month Why not develop 365 forecast equations/year and automate the guidance? We currently do Apr-Jul Streamflow = a * April 1 Snowpack + b Why not something like Apr-Jul Streamflow = a * April 8 Snowpack + b
Period of record range (10, 30, 70, 90 percentile) 1971 -2000 avg Period of record median
Period of record range (10, 30, 70, 90 percentile) 1971 -2000 avg Period of record median Official coordinated outlooks
Daily Update Forecasts Period of record range (10, 30, 70, 90 percentile) 1971 -2000 avg Period of record median Official coordinated outlooks
Official forecasts
Expected skill Daily forecast 50% exceedence Official forecasts
SWSI Methodology varies by state Available 8 Western states Rescaled percentile of [reservoir + streamflow] Calibrated on observed, forced with streamflow forecasts (real-time variance too low) No consistent calibration period
Soil moisture and runoff efficiency
Expansion of soil moisture to SNOTEL network (data starts ~2003)
Blue Mesa Basin, Colorado Soil Moisture 2001 -2008 (According to the Univ Washington Model- top 2 layers)
Blue Mesa Basin, Colorado Soil Moisture 2001 -2008 (According to the Univ Washington Model- top 2 layers) (According to Park Cone Snotel- ~0 -30” depth) Snotel does poorly in frozen soils, so that has been censored Model resembles snotel, but also remember we’re comparing basin average with point measurement
What influence humans? Does it matter? Blue Mesa For each site, all measurements Jan-Jun, Jul-Dec are averaged by year. Station half-year data then converted into standardized anomaly (o-avg(o))/std(o) vs period of record for the half year. Multiple stations are then averaged.
Spring precipitation, especially the sequencing with snowmelt is also important Rainfall Snowmelt Rainfall mixed with snowmelt “normal” Runoff April July
Spring precipitation, especially the sequencing with snowmelt is also important Rainfall Snowmelt Rainfall mixed with snowmelt “normal” Runoff Rainfall boosting snowmelt Larger volumes Snowmelt and rainfall separate Not enough “momentum” to produce big volumes April July All these interactions are tough to “cartoonize”; Simulation models can handle this… but still it’s tough to predict beyond 1 -2 weeks.
Spring precipitation, especially the sequencing with snowmelt is also important Rainfall Snowmelt Rainfall mixed with snowmelt “normal” Runoff Rainfall boosting snowmelt Larger volumes Snowmelt and rainfall separate Not enough “momentum” to produce big volumes Even then, however, high heat and no rain can lead to “pouring sunshine” April July All these complex interactions are tough to “cartoonize”; Simulation models can handle this… but still it’s tough to predict beyond 1 -2 weeks.
Challenges and frontiers
Seasonality/lag of drought in snowmelt regions Precipitation and impacts can be separated by months. Highly managed systems How to separate drought from poor planning or overbuilding? Also: Humans react to forecasts e. g. evacuating reservoirs Regional/local vulnerability Whose drought? Stickiness of drought When is the drought over? Never… (also risk of “Drought fatigue”)
Seasonality/lag of drought in snowmelt regions Precipitation and impacts can be separated by months. Highly managed systems How to separate drought from poor planning or overbuilding? Also: Humans react to forecasts e. g. evacuating reservoirs Regional/local vulnerability Whose drought? Stickiness of drought When is the drought over? Never… (also risk of “Drought fatigue”) Incomplete understanding of natural system (esp soil moist, sublim) Can we even close the water balance? Institutional and infrastructure barriers Limited agency resources, increasing restrictions Non-stationarity Could climate change be the new normal?
The future may have more and better: Products from and understanding of soil moisture data Automation and “smart” objectification of forecast process Quantification and use of anecdotal evidence Forecast transparency (i. e. access to raw guidance)
The future may have more and better: Products from and understanding of soil moisture data Automation and “smart” objectification of forecast process Quantification and use of anecdotal evidence Forecast transparency (i. e. access to raw guidance) Communication of uncertainty, especially graphically Understanding of local user vulnerabilities Consolidation of data from multiple networks: universal, uniform access and multi-agency products Understanding of the “long view”: how relevant is data from 10, 50, 100, 500 years ago?
Variable Snow “Significance” 60 -90 Fall precip Winter precip Spring precip 5 -20 30 -60 10 -25 Baseflow Soil Moisture 5 -15 5 -10 Temperature Wind Radiation Relative humidity 10 -25 5 -20 5 -15 5 -10 Source: 1972 Engineering Handbook
January 1 Daily forecast Skill: (Correlation)2 Variance Explained
April 1 Daily forecast Skill: (Correlation)2 Variance Explained
NWS formats:
NWS formats:
- Drought and desertification
- Sentence for drought
- Types of drought
- Bibliography of drought in south africa
- Aleph toolbox
- Drought presentation
- Anasazi drought
- Conclusion on drought
- Vermont drought monitor
- Utah drought map
- Drought stopper system
- World, drought monitor
- Jordan drought
- Drought present tense
- What are solutions of drought
- Hình ảnh bộ gõ cơ thể búng tay
- Bổ thể
- Tỉ lệ cơ thể trẻ em
- Voi kéo gỗ như thế nào
- Glasgow thang điểm
- Chúa yêu trần thế
- Các môn thể thao bắt đầu bằng từ đua
- Thế nào là hệ số cao nhất
- Các châu lục và đại dương trên thế giới
- Công của trọng lực
- Trời xanh đây là của chúng ta thể thơ
- Mật thư tọa độ 5x5
- Phép trừ bù
- Phản ứng thế ankan
- Các châu lục và đại dương trên thế giới
- Thơ thất ngôn tứ tuyệt đường luật
- Quá trình desamine hóa có thể tạo ra
- Một số thể thơ truyền thống
- Cái miệng nó xinh thế
- Vẽ hình chiếu vuông góc của vật thể sau
- Thế nào là sự mỏi cơ
- đặc điểm cơ thể của người tối cổ
- V. c c
- Vẽ hình chiếu đứng bằng cạnh của vật thể
- Tia chieu sa te
- Thẻ vin
- đại từ thay thế
- điện thế nghỉ
- Tư thế ngồi viết
- Diễn thế sinh thái là
- Dot
- Thế nào là số nguyên tố
- Tư thế ngồi viết