28032016 reg ndvi anomaly...
TRANSCRIPT
The Regional Food Security Analysis Network (RFSAN) is a joint initiative by FAO and iMMAP and isfunded by the United States Agency for International Development (USAID)/ Food For Peace (FFP).The boundaries, names and designations used in this map do not imply official endorsement oracceptance by FAO, iMMAP or USAID.
Explanation
The NDVI provides a measure of the amount and vigour (greenness) of vegetation at the land surface. The magnitude of NDVI is related to the level of photosynthetic activity in the observed vegetation. In general, higher values of NDVI indicate greater vigour and amounts of vegetation.Anomalies represent a subtraction of the mean Normalised Difference Vegetation Index (NDVI values) for a -10day period from current-year values for the same period, rendering an image where negative values (brown) portray less vigorous vegetation than average, and positive values (green) represent areas that are more vigorous in the current year.Mean Anomaly- The long term mean anomaly is a subtraction of the mean NDVI values (2001-2015) for a 10 day period from current-year values for the same period.Previous Year Difference –The difference image is a subtraction of the current year NDVI values from those of the previous year for the same -10day time period.Anomaly/ Difference Classi�cation: The absolute difference and anomaly images are stretched from 0.3- (brown or less vegetation activity) to 0.3 (green/more vegetation activity) NDVI.The area of relatively no difference is approximately 0.05 – 0.05.
nearinfrared Visible
30%
(0.40 - 0.30)(0.40 + 0.30)= 0.14
40%8%50%
nearinfrared Visible
(0.50 - 0.08)(0.50 + 0.08) = 0.72
Analysis
Temperature conditions have been hotter than average across the region for February and March, 2016, and medium term Forecasts by the World Meteorological Organization Lead Center for Long-Range Forecast also indicate the probability of temperatures being above normal for the season (March-April-May). Precipitation has also been below the long term average over Syria in February, 2016 and this coupled with the higher temperatures has seen vegetation growth for this time period to be below average. 2015 had a higher than expected precipitation and therefore shows a greater NDVI difference for 2016 than compared to the Long Term Average. Vegetation conditions look good over the northern areas of Iraq when compared to the long term average, while north-eastern Syria is below the conditions of the previous year and the long term average.It is still too early in the season to state whether crop production will be affected by weather conditions, and RFSAN will continue to monitor the situation. RFSAN also produces rainfall and Agricultural Stress Index products on a monthly basis, and these should be used in conjunction with these NDVI products.
11-20 March time period- 2016 2015
11-20 March time period2015 - Long term Average
NDVI Difference
REGIONAL FOOD SECURITY ANALYSIS NETWORKDate created: 29 March 2016Map No. NDVI_anomaly_20-11_2016MarchData/Projection: UTM [email protected]
Data Sources: NDVI – eMODIS 250m, USGS and FEWS NET;Administration boundaries: FAO/GAUL; Cities, Waterbodies – ESRI;Cities, Waterbodies: Environmental Systems Research Institute (ESRI)
50km
050
km
0
+ve
No difference
-0.3 +0.3
-ve
Snow/No data
11 - 20 March
Elazig
Malatya
AdiyamanKahramanmaras
SanhurfaGaziantepSeyhan
Antakya
Al Ladhiqiyah
Tartus
ZahleB'abda
Ar RaqqahIdlib
Hamah
BingolMus
Bitlis
SiirtDiyarbakir
Mardin
Al-Hasakah
Dayr azZawr
Van
Hakkari
Dahuk
Arbil
Kirkuk
Samarra
At Tafilah
As Suwayda
Ma'an
Sidon
Nabatiyet et Tahta
Al Qunaytirah
Dar'aIrbid
Al MafraqAz Zarqa'As-Salt
Al Karak
Ba qubah
Ar-Ramadi
Karbala'Al-Hillah
Ad DiwaniyahAn Najaf
Al-Kut
Al 'Amarah
As-SamawahAn-Nasiriyah
As-Sulaymaniyah
Elazig
Malatya
AdiyamanKahramanmaras
SanhurfaGaziantepSeyhan
Al Ladhiqiyah
Tartus
ZahleB'abda
Ar RaqqahIdlib
Hamah
BingolMus
Bitlis
SiirtDiyarbakir
Mardin
Al-Hasakah
Dayr azZawr
Van
Hakkari
Dahuk
Arbil
Kirkuk
Samarra
At Tafilah
As Suwayda
Ma'an
Sidon
Nabatiyet et Tahta
Al Qunaytirah
Dar'aIrbid
Al MafraqAz Zarqa'As-Salt
Al Karak
Ba qubah
Ar-Ramadi
Karbala'Al-Hillah
Ad DiwaniyahAn Najaf
Al-Kut
Al 'Amarah
As-SamawahAn-Nasiriyah
As-Sulaymaniyah
Antakya
Beirut
Damascus
Amman
Baghdad
Beirut
Damascus
Amman
Baghdad