Environmentfocused adaptation

The previous section explored the impact of climate change and the effect of adaptation strategies on food production and food security. Similarly we have explored what can be done to enhance environmental quantity and security. Figures 10.6 and 10.7 show what the impact on the environment will be of the two most relevant adaptation measures related to water: (i) changing water diverted to agriculture; and (ii) changing the cropped area. As explained earlier, we have selected the total long-term outflow of the basin and the derivation from the defined minimum flow of 100 X 106 m3/year to express environmental quality and security.

The reference period shows that currently about 200 X 106 m3 flows out of the basin and the minimum flow requirement is not met in about 25% of the years. The graph can be used to explore what would have happened if the cropped area or the diversion to irrigation were different. However, it is more interesting to look at what will happen in the future if the irrigation depths and the cropped area remain unchanged. For the two time periods in the future, the overall impact on the environment will be positive. Total outflow will increase, and the number of years with low flow will increase somewhat for the 2010-2039 period, but decrease for 2070-2099. If this increase in low flow years is unacceptable, or if the policy is that low flows are only accepted in, for example, 10% of the years, then a decrease in the cropped area and/or a decrease in the water extracted for irrigation is unavoidable.

These environmental adaptation strategies should not be considered in isolation, but the effect on food should be included as well. In general, improving environmental quality and security by decreasing the cropped area will result in lower total production. Alternatively, decreasing the diversions to irrigation will have a minor impact on total food production, but will increase the variation in food production.

Again, it is the policy maker who should decide what the future should look like. The results presented here aim to help in making sound decisions.

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