Urban farming and urban water management

| Prospects & Investment |

Let us take a look at research done by Mark Johnson from the University of British Columbia. Johnson and his team focused on the impact of city farming on urban water reserves. The results of this study have provided important arguments in the debate about urban farming, a trend which has been gaining popularity.

Methodology of the study

For his research, Mark Johnson created a model explaining the water consumption of urban crops in Vancouver. Using data on climate change and LIDAR (the tool is similar to a radar, but it measures air temperature and clarity; it this case it was used for measuring the amount of shade), the model specifies water evaporation level, helping to calculate the amount of water required by urban farms. The model was applied to one square kilometer of a typical residential district in Vancouver.

The results

Some of the findings appear optimistic. Water evaporation proved 10% lower in comparison with crops growing in full sunlight. Also, the model showed that urban crops used 17% less water than an average lawn, while they could help meet 37% of the local population’s demand for vegetables (provided that the growing season lasts 150 days).
However, the washing of root crops generates additional water consumption, and the total use of water might exceed the amount needed to maintain an average lawn. According to some statistics, if the scale of urban farming increased considerably, the demand for water in a city could grow by as much as 50%, which would prove especially problematic in the areas where water supply is limited.

What will the future bring?

On the other hand, the findings are by no means pessimistic. The authors of the study have suggested that the additional demand for water could be met using recycling, rain-water harvesting and drip irrigation. With the city population on the increase, we might well see the need to replace lawns with vegetable crops shortly. With this possibility in view, it is good to know that researchers have already begun to look into the pros and cons of urban farming.