Greenhouses in the inner districts of Đà Lạt in the Central Highlands.VNS File Photo/Zing.vn

LÂM ĐỒNG -- The rapid development of greenhouses for vegetable and flower cultivation in the last two decades has had a negative effect on the environment in the central resort city of Đà Lat. 

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 per cent 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 Lâm Đồng Province.

Lại Thế Hưng, head of the Division of Plant Protection, said the province’s Agriculture Department had asked the Lâm Đồng People’s Committee to set specific criteria on where greenhouses and nethouses could be located.

Under the proposal, greenhouses would be permitted on 80 per cent of areas (for building greenhouses) in Lâm Đồng Province and the remaining 20 per cent 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 Hưng.

To minimise the environmental impact of greenhouse expansion, the Agriculture Department should identify areas that can drain rainfall from the upper section of Đà Lạt, he added.

Dr Nguyễn Mộng Sinh, ex-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 Đà Lạt 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 Đà Lạt, he added.

Lâm Đồng Province has 4,500 ha of greenhouses and 1,222 ha of nethouses. Đà Lạt has about 2,800ha of greenhouses, including 1,244ha for growing vegetables, and 1,590ha for planting flowers, according to the Lâm Đồng Department of Agriculture and Rural Development .-- VNS.