Early season drought in Zimbabwe and Mozambique
Figure 1: Average RE last 3 months of 2012 Figure 2: Difference relative to 2004-2009
The onset of the growing season was late in Zimbabwe and Mozambique. In large parts of the area the average relative evapo-transpiration (RE) during the period from October to November 2012 was stabbing around 50%, as shown in figure 1. The dry conditions in this area are particularly clear from figure 2, which shows the difference relative to the average of the previous 8 year. There is a considerable negative anomaly (red to black colors) showing plant water availability to be 10-20% below average. Conditions were notably better in the very south of Mozambique and southward along the coast of South Africa.
Figure 3: Avrg RE last 10 days of 2012
During the last 10 days of December, water availability in the region had considerably improved, as shown in figure 3. However in the South of Zimbabwe and just across the border in Mozambique a dry anomaly still persists. The situation in this part is well illustrated in the RE time course of a 9*9 pixel average as shown by the graph in figure 4 below.
A considerable effect on end of season crop yield may be expected. In the first place because of the proportionality between the relative evapotranspiration and crop growth. In the second place because a late onset of the season is often associated with an early end. Crop yield forecasts at national, provincial and district level are to start halfway the growing season, i.e. from February 2013 on. Updates may thereafter be prepared every 10 days.
Figure 4: Time course of dekad relative evaptranspiration during the period 2004-2013. Low RE values at the end of 2012 clearly depict te anomalous conditions at the end of 2012.