This yr witnessed one of many hottest and driest summers in current historical past for Western Canada and the American Southwest. The ensuing droughts adversely affected meals provide and helped ship meat costs rising 3 times quicker than inflation.
Regardless of the severity of those droughts, the worst could also be but to return. Excessive climate occasions are anticipated to grow to be more and more extreme and frequent within the Prairies, with longer dry durations coupled with the danger of floods from intense rainstorms.
Whereas Canada advantages from a world-class agricultural know-how trade, classes will also be drawn from low-tech options developed by historical societies that flourished in arid climates. One such society was the Nabataean tradition, which thrived within the hyper-arid deserts of Jordan, northern Saudi Arabia and southern Israel 2,000 years in the past. For over a decade, I’ve labored on Nabataean and Roman archeological websites of this area, exploring their constructing practices and progressive methods for overcoming environmental limitations.
Masters of hydraulic engineering
Identified for his or her rock-carved monumental facades on the UNESCO World Heritage websites of Petra (their capital) and Hegra, the Nabataeans grew wealthy from buying and selling incense between southern Arabia and the Mediterranean. But it surely was one other talent that allowed them to flourish of their arid homeland.
Drawing on native methods in addition to these adopted from neighbouring cultures, the Nabataeans grew to become masters of hydraulic engineering. They constructed complicated water administration methods that included dams, catchment methods, underground cisterns and aqueducts. These methods have been designed to maximise the quantity of rainwater collected and saved through the moist winter months and to reduce the quantity of water misplaced by way of evaporation through the dry summer time months.
(AP Photograph/Sam McNeil)
At Petra, the Nabataeans constructed a community of dams to guard their capital from flash floods and coated channels to ship water to town centre. Within the surrounding hillsides, they constructed terraces to soak up runoff, mitigating flood danger and supporting agriculture. So efficient have been these catchment and supply methods that the Nabataeans constructed open-air swimming pools and monumental fountains in Petra as ostentatious shows of their wealth and energy.
South of Petra, on the archeological website of Hawara (trendy Humayma), Canadian archeologists have explored and documented the settlement’s intensive water provide system. Right here, catchment methods directed rainwater runoff to giant cisterns that saved it to be used within the dry season. These cisterns have been roofed to forestall evaporation and have been furnished with settling basins to gather sediment. A 26.5-kilometre spring-fed aqueduct additionally provided this settlement with ingesting water. A lot of this method remains to be in use at this time.
Historic methods for a contemporary drawback
Regardless of being developed and constructed two millennia in the past, efforts are presently underway to revitalize the Nabataean water administration methods round Petra to assist with flood management and help agricultural improvement. Elsewhere throughout the globe, archeology has superior our understanding of sustainable farming and holds the potential to contribute meaningfully to up to date water politics. Whereas implementation of those historic options could not by themselves resolve the complicated points we presently face, they’ll doubtless play an necessary position in serving to us adapt to a hotter and dryer local weather.
Though the local weather and hydrology of the Canadian Prairies are very totally different from the deserts of northern Arabia, some similarities exist. Simply as winter rains in northern Arabia sustained life through the summer time months, runoff from snow soften within the Prairies performs an necessary position in recharging groundwater and represents a good portion of stream movement through the spring.
(John Oleson), Creator offered
Just like the underground cisterns constructed by the Nabataeans, excavated depressions generally known as dugouts are an necessary supply of water for Prairie farmers. Whereas these human-made reservoirs will be provided by groundwater, they usually depend on spring snow soften. Through the drought situations of this previous summer time, nevertheless, many of those dugouts dried up, forcing many farmers to depend on pumped groundwater, which comes with its personal set of points.
Adopting sustainable practices much like these utilized by the Nabataeans to maximise the quantity of water collected and decrease the quantity misplaced to evaporation may help enhance the effectiveness of those reservoirs. Simply because the Nabataeans positioned their cisterns to maximise the catchment of runoff, dugouts must be strategically situated in fields to gather as a lot snow soften as attainable. The quantity of snow soften captured will be additional elevated by means of well-designed shelterbelts, which comprise rows of bushes and shrubs that act as a windbreak and may encourage the buildup of snow.
Settling tanks resembling those the Nabataeans constructed to forestall the buildup of sediment of their cisterns, is also used to forestall sedimentation in dugouts, enhancing each storage capability and water high quality.
(AP Photograph/Wealthy Pedroncelli)
The Nabataeans have been additionally cautious to keep away from evaporation, and trendy dugouts could profit from being coated to reduce water loss. World research have proven the effectiveness of bodily covers at slowing the speed of evaporation, and not too long ago California proposed masking its canals with photo voltaic panels to assist preserve its water provide whereas additionally producing inexperienced electrical energy.
A part of an built-in technique
Whereas better funding in water storage methods will enhance water safety within the Prairies and mitigate the impacts of extended droughts, these storage methods may have the additional benefit of decreasing flood danger by retaining runoff.
Though the adoption of those low-tech and sustainable options is not going to by themselves drought-proof the Prairies, when mixed with progressive cropping methods they might play an necessary position in serving to Canada’s farmers mitigate the rising impacts of local weather change.