James Rowland (Former Employee)
Science and Products
Filter Total Items: 47
Temporal analysis of floodwater volumes in New Orleans after Hurricane Katrina Temporal analysis of floodwater volumes in New Orleans after Hurricane Katrina
Satellite images from multiple sensors and dates were analyzed to measure the extent of flooding caused by Hurricane Katrina in the New Orleans, La., area. The flood polygons were combined with a high-resolution digital elevation model to estimate water depths and volumes in designated areas. The multiple satellite acquisitions enabled monitoring of the floodwater volume and extent...
Authors
Jodie Smith, James Rowland
Spatial data infrastructures in management of natural disasters Spatial data infrastructures in management of natural disasters
No abstract available.
Authors
K.O. Asante, J. P. Verdin, M.P. Crane, S.A. Tokar, James D. Rowland
Recent drought tendencies in Ethiopia and equatorial-subtropical eastern Africa Recent drought tendencies in Ethiopia and equatorial-subtropical eastern Africa
This report presents an analysis of Ethiopian rainfall from 1960 through 2004, based on 186 gauges in Ethiopia and 373 gauges from surrounding countriesi. Substantial post1997 declines in March-September rainfall have been observed in the northeast, southeast and southwestern portions of the country, a result corroborated by several independent data sourcesii. The observed rainfall...
Authors
Chris Funk, Gabriel Senay, Alemu Asfaw, James Verdin, Jim Rowland, Diriba Korecha, Gary Eilerts, Joel Michaelsen, Saud A. Amer, Richard Choularton
Drought monitoring techniques for famine early warning systems in Africa Drought monitoring techniques for famine early warning systems in Africa
No abstract available.
Authors
James D. Rowland, J. P. Verdin, A. Adoum, G.B. Senay
Assessing land cover performance in Senegal, West Africa using 1-km integrated NDVI and local variance analysis Assessing land cover performance in Senegal, West Africa using 1-km integrated NDVI and local variance analysis
The researchers calculated seasonal integrated normalized difference vegetation index (NDVI) for each of 7 years using a time-series of 1-km data from the Advanced Very High Resolution Radiometer (AVHRR) (1992-93, 1995) and SPOT Vegetation (1998-2001) sensors. We used a local variance technique to identify each pixel as normal or either positively or negatively anomalous when compared to...
Authors
M.E. Budde, G. Tappan, James Rowland, J. Lewis, L.L. Tieszen
Evaluation of land performance in Senegal using multi-temporal NDVI and rainfall series Evaluation of land performance in Senegal using multi-temporal NDVI and rainfall series
Time series of rainfall data and normalized difference vegetation index (NDVI) were used to evaluate land cover performance in Senegal, Africa, for the period 1982–1997, including analysis of woodland/forest, agriculture, savanna, and steppe land cover types. A strong relationship exists between annual rainfall and season-integrated NDVI for all of Senegal (r=0.74 to 0.90). For...
Authors
Ji Li, J. Lewis, James Rowland, G. Tappan, L.L. Tieszen
Estimating Meher crop production using rainfall in the 'Long Cycle' region of Ethiopia Estimating Meher crop production using rainfall in the 'Long Cycle' region of Ethiopia
Meher season crop production is well correlated with April-May rainfall in the Ethiopian 'long cycle' crop growing region. This relationship is used to estimate 2003 Meher small farmer gross production at 87 =B1 10 million quintals (8.7 million MT2 =B1 1 million MT) of cereals, pulses and other crops, using data from the Central Statistical Authority (CSA). Assuming recent levels of...
Authors
Chris Funk, Alemu Asfaw, Phil Steffen, Gabriel Senay, James Rowland, James Verdin
Interactive visualization of vegetation dynamics Interactive visualization of vegetation dynamics
Satellite imagery provides a mechanism for observing seasonal dynamics of the landscape that have implications for near real-time monitoring of agriculture, forest, and range resources. This study illustrates a technique for visualizing timely information on key events during the growing season (e.g., onset, peak, duration, and end of growing season), as well as the status of the current...
Authors
B. C. Reed, D. Swets, L. Bard, J. Brown, James Rowland
A weighted least-squares approach to temporal NDVI smoothing A weighted least-squares approach to temporal NDVI smoothing
Satellite imagery provides a unique vantage point for observing seasonal dynamics of the landscape that have implications for global change issues. An objective evaluation of surface conditions may be performed using the normalized difference vegetation index (NDVI) derived from National Oceanic and Atmospheric Administration advanced very high resolution radiometer data. NDVI data are...
Authors
D. Swets, Bradley C. Reed, James Rowland, S.E. Marko
Estimating maize production in Kenya using NDVI: Some statistical considerations Estimating maize production in Kenya using NDVI: Some statistical considerations
A regression model approach using a normalized difference vegetation index (NDVI) has the potential for estimating crop production in East Africa. However, before production estimation can become a reality, the underlying model assumptions and statistical nature of the sample data (NDVI and crop production) must be examined rigorously. Annual maize production statistics from 1982-90 for...
Authors
J.E. Lewis, James Rowland, A. Nadeau
Vegetative index for characterizing drought patterns Vegetative index for characterizing drought patterns
No abstract available.
Authors
James D. Rowland, A. Nadeau, J. C. Brock, R. W. Klaver, D. G. Moore, J. Lewis
Science and Products
Filter Total Items: 47
Temporal analysis of floodwater volumes in New Orleans after Hurricane Katrina Temporal analysis of floodwater volumes in New Orleans after Hurricane Katrina
Satellite images from multiple sensors and dates were analyzed to measure the extent of flooding caused by Hurricane Katrina in the New Orleans, La., area. The flood polygons were combined with a high-resolution digital elevation model to estimate water depths and volumes in designated areas. The multiple satellite acquisitions enabled monitoring of the floodwater volume and extent...
Authors
Jodie Smith, James Rowland
Spatial data infrastructures in management of natural disasters Spatial data infrastructures in management of natural disasters
No abstract available.
Authors
K.O. Asante, J. P. Verdin, M.P. Crane, S.A. Tokar, James D. Rowland
Recent drought tendencies in Ethiopia and equatorial-subtropical eastern Africa Recent drought tendencies in Ethiopia and equatorial-subtropical eastern Africa
This report presents an analysis of Ethiopian rainfall from 1960 through 2004, based on 186 gauges in Ethiopia and 373 gauges from surrounding countriesi. Substantial post1997 declines in March-September rainfall have been observed in the northeast, southeast and southwestern portions of the country, a result corroborated by several independent data sourcesii. The observed rainfall...
Authors
Chris Funk, Gabriel Senay, Alemu Asfaw, James Verdin, Jim Rowland, Diriba Korecha, Gary Eilerts, Joel Michaelsen, Saud A. Amer, Richard Choularton
Drought monitoring techniques for famine early warning systems in Africa Drought monitoring techniques for famine early warning systems in Africa
No abstract available.
Authors
James D. Rowland, J. P. Verdin, A. Adoum, G.B. Senay
Assessing land cover performance in Senegal, West Africa using 1-km integrated NDVI and local variance analysis Assessing land cover performance in Senegal, West Africa using 1-km integrated NDVI and local variance analysis
The researchers calculated seasonal integrated normalized difference vegetation index (NDVI) for each of 7 years using a time-series of 1-km data from the Advanced Very High Resolution Radiometer (AVHRR) (1992-93, 1995) and SPOT Vegetation (1998-2001) sensors. We used a local variance technique to identify each pixel as normal or either positively or negatively anomalous when compared to...
Authors
M.E. Budde, G. Tappan, James Rowland, J. Lewis, L.L. Tieszen
Evaluation of land performance in Senegal using multi-temporal NDVI and rainfall series Evaluation of land performance in Senegal using multi-temporal NDVI and rainfall series
Time series of rainfall data and normalized difference vegetation index (NDVI) were used to evaluate land cover performance in Senegal, Africa, for the period 1982–1997, including analysis of woodland/forest, agriculture, savanna, and steppe land cover types. A strong relationship exists between annual rainfall and season-integrated NDVI for all of Senegal (r=0.74 to 0.90). For...
Authors
Ji Li, J. Lewis, James Rowland, G. Tappan, L.L. Tieszen
Estimating Meher crop production using rainfall in the 'Long Cycle' region of Ethiopia Estimating Meher crop production using rainfall in the 'Long Cycle' region of Ethiopia
Meher season crop production is well correlated with April-May rainfall in the Ethiopian 'long cycle' crop growing region. This relationship is used to estimate 2003 Meher small farmer gross production at 87 =B1 10 million quintals (8.7 million MT2 =B1 1 million MT) of cereals, pulses and other crops, using data from the Central Statistical Authority (CSA). Assuming recent levels of...
Authors
Chris Funk, Alemu Asfaw, Phil Steffen, Gabriel Senay, James Rowland, James Verdin
Interactive visualization of vegetation dynamics Interactive visualization of vegetation dynamics
Satellite imagery provides a mechanism for observing seasonal dynamics of the landscape that have implications for near real-time monitoring of agriculture, forest, and range resources. This study illustrates a technique for visualizing timely information on key events during the growing season (e.g., onset, peak, duration, and end of growing season), as well as the status of the current...
Authors
B. C. Reed, D. Swets, L. Bard, J. Brown, James Rowland
A weighted least-squares approach to temporal NDVI smoothing A weighted least-squares approach to temporal NDVI smoothing
Satellite imagery provides a unique vantage point for observing seasonal dynamics of the landscape that have implications for global change issues. An objective evaluation of surface conditions may be performed using the normalized difference vegetation index (NDVI) derived from National Oceanic and Atmospheric Administration advanced very high resolution radiometer data. NDVI data are...
Authors
D. Swets, Bradley C. Reed, James Rowland, S.E. Marko
Estimating maize production in Kenya using NDVI: Some statistical considerations Estimating maize production in Kenya using NDVI: Some statistical considerations
A regression model approach using a normalized difference vegetation index (NDVI) has the potential for estimating crop production in East Africa. However, before production estimation can become a reality, the underlying model assumptions and statistical nature of the sample data (NDVI and crop production) must be examined rigorously. Annual maize production statistics from 1982-90 for...
Authors
J.E. Lewis, James Rowland, A. Nadeau
Vegetative index for characterizing drought patterns Vegetative index for characterizing drought patterns
No abstract available.
Authors
James D. Rowland, A. Nadeau, J. C. Brock, R. W. Klaver, D. G. Moore, J. Lewis