1. Application of Earth Observation data in Agricultural drought monitoring Farai Kuri University of Zimbabwe

2. Introduction  Drought traditionally measured using rainfall data  Rainfall indices an indirect measure of drought  Remote sensing drought indices are plant based  EO is therefore a direct measure of plant performance

3. Objectives  To test whether and to what extent EO based drought indices can predict maize yield in Zimbabwe

4. Materials and Methods

5. Study area  Study was based on the whole of Zimbabwe

6. Data  Maize yield data courtesy of Ministry of Agriculture Mechanisation and Irrigation Development (2009-2010 & 2011-2012)  SPOT VGT NDVI long-term series AMESD Station at SIRDC and UZ (1998-2012)

7. Data Analysis  Calculated Vegetation Condition Index (VCI) from SPOT NDVI series  VCI<36%, Dry dekad (1), Not Dry ( 0)  Frequency of dry dekads calculated for 2009- 2010 & 2011-2012

8. Relating Drought to Maize Yield  Regression was used to test whether and to what extent EO based dry dekads can predict maize yield.

9. In-Situ Maize Yield 2011-12

10. Frequency of Dry Dekads (2011-12 )

11. Results

12. In-Situ Maize Yield 2009-10

13. Frequency of Dry Dekads (2009-10)

14. Y=1/(0.25+0.02827*2.3038 x R²=0.91 P-Value=0.001

15. Conclusion  There is a significant relationship between frequency of RS based dry dekads and maize yield  Therefore frequency of RS based dry dekads can be used to evaluate impact of drought on yield or to estimate crop yield

16. Thank You