Soil scientist assesses Erika's impact
As the nation struggles to come to terms with the incalculable loss of lives and property, troubling questions arise.
What factors made the effects of Tropical Storm Erika worse? Why did they occur? Can they be eliminated or mitigated to offset the impact of future natural disasters?
The Sun newspaper turned to experienced soil scientist and outspoken environmentalist Atherton Martin for answers.
His perception of the situation is crystal clear. Dominica's vulnerability to natural disasters was worsened by chronic misunderstanding of the environment.
Dominicans simply ignored the nature of the environment and changed it to suit themselves without regard for the destabilizing effects of such adjustments, Martin said.
For instance, many persons do not understand that the essential element of a river is its source. "People don't understand that a water system begins with a healthy water catchment," Martin lamented.
"As a soil scientist, you understand very quickly that the soils that you end up having to work with for agriculture on the flat have their origins in that same catchment," Martin said.
"You also understand that if you mismanage a water catchment you will have a constant movement of surface soil-- and eventually of subsoil-- from the hillsides down to the flat."
This can dramatically change the nature of the soil in the area, he warned. "It changes the fertility; it changes the drainage and ultimately changes what you can grow on it. . .
"The growth medium that you are starting with didn't start where it is…the more you know of its origins, the better you can manage that soil," he explained.
Furthermore, Martin said instability from natural soil movement and accretion issues is compounded by Dominica's mountainous topography with active volcanoes causing constant subterranean movements.
Martin put it plainly: surface instability is inevitable because Dominica is sitting on "a sea of lava".
Additionally, the Caribbean archipelago is on the Caribbean plate-- a region of intense seismic activity -- that is being subtly lifted by the Atlantic plate.
Miniscule adjustments in the plates can cause major shifts, perhaps creating new fractures or fissures or re-diverting the flow of lava or seepage of water, Martin said.
Despite this background, he noted that Dominicans built wherever they wanted for over 50 years with little regard for flooding or landslide risks or the implications for the environment.
"We were not only disregarding the natural systems like our soils, our water systems, our tree systems . . . we were distorting them. . . causing upheaval!" Martin said.
Houses were built on river beds and moving slopes; builders sunk pillars into the subsoil, mistakenly thinking they were safe on solid ground. "It's not solid ground . . . the entire hillside is moving . . . and in the way of the hillside is your house . . . there are many, many places like that," he explained.
Owners of homes on unstable slopes built huge retaining walls, Martin said, adding that photographs of rivers 50-100 years ago show no buildings close to the rivers because builders knew rivers overflowed during heavy rainfall.
Moreover, Martin claimed planning laws dating back to the 1960s weren't fully enforced because authorities were flexible and permitted construction in unsuitable locations.
Many locations were unsuitable for septic tanks and soakaways [pits into which waste water is piped so that it drains slowly out into the surrounding soil], such as Piccard.
"Piccard is a health disaster. Piccard should be shut down…the reason Piccard is a cesspool is because…the flat is a swamp . . . a lot of sewage is sitting there…." Martin declared.
The net effect of improper treatment of the environment is that manmade hazards emerged and natural hazards become more dangerous. And a decline in the flow of rivers allows invasive plants occupy land where they couldn't survive before, he said.
Martin recalled a land capability classification study of Dominica by Canadian soil scientist David Lang in 1972, which mapped the island according to crop suitability.
"Have we used that information? The answer is no. Do we have people who know how to use it? The answer is yes. Why haven't we used it? Because it means starting to tell people what they can and cannot do with their ….private land," he said.
Dominica's land was then heavily used for bananas, but Lang estimated that only 20% of the land was suitable for this; the remainder was suitable for other types of crops.
Martin pointed out that Dominica's small size makes it important to take care of every bit of land, especially in the context of climate change and more frequent storms.
As such, training more geologists, soil scientists and agronomists is essential, he said, to help Dominica adopt a more environmentally conscious approach to construction and agriculture.
He noted that discarded tyres can be recycled and used for durable road construction, and farmers can be encouraged to plant crops suitable to the environment, like deep-rooted crops that can thrive on slopes.
Zoning to specify suitability of coastal areas, river courses and mountain sides is also essential, he said, adding that many coastal communities will have to be relocated over the next 10 years, failing which they will cease to exist.
In that regard, he recommended that the site selected to relocate Petite Savanne evacuees should be used as a model village built "to fix the problem".