Bali is currently facing serious environmental degradation with possible food and water supply shortage, a study reveals.

The study, jointly conducted by the University of Udayana's Environmental Study and Bali Development and Planning Agency, shows a food and water crisis is now haunting the island's rocketing population.

I Wayan Arthana, head of environmental studies, explained the conditions occurred because of limited fertile land for growing rice and food commodities.

Water supply is limited due to water pollution and unwise development projects along the island's water resources, including river beds and lake and water-catchment areas.

"The authority needs to carry out strict population control and ongoing campaigns to raise people's awareness on the current environmental issues to reduce the impact of the problem," Arthana said.

The study said that Bali needed at least 516,000 hectares of productive land to provide for its 3.3 million population.

The island has only 325,000 hectares of fertile land. Arthana said that since Bali also hosted 1.9 million visitors annually, it should have a minimum 521,000 hectares of productive land.

Its six regencies facing serious land problems include Denpasar, Badung, Gianyar, Jembrana and Buleleng. Rapid construction projects in the six regencies have transformed productive land such as rice fields and plantations into residential and business sites.

Only one regency, Bangli, still has a large amount of fertile land. Based on a decree issued by the Environment Ministry, one person needs 1,000 kilograms of rice valued at Rp 430,000 (US$48) per month.

Meanwhile, in Bali, one person may spend double than the basic living minimum set by the ministry.

In addition to limited food supplies, the island is also prone to water scarcity.

The island's water supply is only 4.7 million cubic meters per year, while 5.4 million cubic meters is used annually.

Bali also faces a crucial population problem, the study says. According to a standard set by the World Health Organization, ideally Bali should only house a 1,000,400 population.

Based on the national standard, Bali can still hold 1,000,580 people, while 1.6 million people is tolerable, compared to the present 3.32 million population.

The three densely populated areas include Badung, Denpasar and Gianyar. Arthana said the study revealed a number of recommendations for the government. "We urged the local administration to stop converting productive land to make way for construction projects."

Agung Wardana, environment activist and former chairman of Bali Friends of the Earth, urged local authorities to halt construction projects, especially those intended for tourist-related facilities.

The group identified five serious violations in regard to spatial law. The first case involved land conversion of Dasong forest and Buyan Lake in Buleleng regency. Other violations included Padang Bai and Kelating Beach in Tabanan.