Greenhouses for vegetable and flower cultivation in Da Lat city (Photo: zing.vn)
Greenhouses have been used in the city to minimise the impact caused by inclement weather, including rainfall, storms, hailstones, hoar frost and humidity.
However, many of them have been built on urban land, which has reduced the amount of rainfall absorbed into the soil and lowered the underground water level. This has also contributed to increased flooding in many areas.
About 70 percent of the greenhouses have not met technical standards, contributing to the spread of disease and viruses, according to a spokesman from the Department of Agriculture and Rural Development’s Division of Plant Protection in Lam Dong province.
Lai The Hung, head of the Division of Plant Protection, said the provincial Department of Agriculture and Rural Development had asked the Lam Dong People’s Committee to set specific criteria on where greenhouses and nethouses could be located.
Under the proposal, greenhouses would be permitted on 80 percent of areas (for building greenhouses) in Lam Dong province and the remaining 20 percent for planting trees and building inner roads.
When building greenhouses, residents have been asked to take into account the facilities' slope and drainage networks, and estimate the volume of water that will flow out and where the water will flow, especially from glasshouses covering 5 hectares, according to Hung.
To minimise the environmental impact of greenhouse expansion, the Department of Agriculture and Rural Development should identify areas that can drain rainfall from the upper section of Da Lat, he added.
Dr Nguyen Mong Sinh, former chairman of the province's Union of Science and Engineering Technology Associations, said that areas for agricultural production and vegetable cultivation should be re-located to suitable zones.
To reduce flooding and environmental impact, Sinh said greenhouses in the central areas of Da Lat must be moved to suburban areas and replaced with trees and other greenery.
State agencies should work with the owners of these houses and create favourable conditions by offering job opportunities for residents who agree to move their facilities to the suburban areas of Da Lat, he added.
Lam Dong province has 4,500 ha of greenhouses and 1,222 ha of nethouses. Da Lat has about 2,800ha of greenhouses, including 1,244ha for growing vegetables, and 1,590ha for planting flowers, according to the Lam Dong Department of Agriculture and Rural Development.