The Lombok Strait is located to the west of the island and marks the passage of the biogeographical divide between the prolific fauna of the Indomalayan ecozone and the distinctly different, but equally prolific fauna of Australasia—this distinction is known as the “Wallace Line” (or “Wallace’s Line”) and is named after Alfred Russel Wallace. Wallace was the first to make a remark on the separation of the two areas, as well as the abrupt border between the two biomes.
The Alas Strait, a thin body of water to the east of Lombok, separates the island of Lombok from the neighbouring island of Sumbawa.
The centrally positioned stratovolcanoMount Rinjani, Indonesia’s second tallest volcano, rises to 3,726 m and dominates the island’s landscape (12,224 ft). Rinjani’s most recent eruption occurred in May 2010 near Gunung Barujari. Ash was reported to be rising two kilometers into the sky from Rinjani’s caldera lake of Segara Anak’s Barujari cone. Lava spilled into the caldera lake, boosting its temperature, while ash fall devastated farms on Rinjani’s slopes. The Gunung Rinjani National Park, which was formed in 1997, protects the volcano and its crater lake, ‘Segara Anak’ (child of the sea). According to recent evidence, an old volcano, Mount Samalas, of which only a caldera remains, was the site of one of the biggest volcanic eruptions in recorded history, producing global climatic shifts.
Lombok’s highlands are primarily forested and underdeveloped. The lowlands are densely populated. Rice, soybeans, coffee, tobacco, cotton, cinnamon, cacao, cloves, cassava, maize, coconuts, copra, bananas, and vanilla are the main crops farmed on the island’s lush soils. The southern half of the island is rich yet arid, particularly along the shore.
Lombok’s water supply is strained, putting a burden on both the water supply of the provincial capital, Mataram, and the island as a whole. The southern and central regions are said to be the most severely hit. The province of West Nusa Tenggara in general is facing a water problem as a result of rising forest and water table erosion and degradation. It is estimated that 160 thousand hectares out of a total of 1960 thousand hectares were damaged. Forest West Nusa Tenggara’s Head of Built Environment and Security Forest Service On Wednesday, May 6, 2009, Andi Pramari declared in Mataram that, “If this problem is not solved, it is possible that residents in this section of NTB may find it difficult to receive water within the next five years (West Nusa Tenggara). Not only that, but agricultural output in terms of value added will decline, and inhabitants will face water scarcity in their wells “.. This situation is exacerbated by a high rate of wood theft in the NTB area.
In September 2010, several people in Central Lombok were reported to have walked for several hours to obtain a single pail of water. Nieleando, a little beach community approximately 50 kilometers from Mataram, has been plagued by dry wells for years. It has been stated that the situation periodically develops to the point that disagreements and violence amongst villages occur. The most severe difficulties have been observed in the districts of Jonggat, Janapria, Praya Timur, Praya Barat, Praya Barat Daya, and Pujut. Provincial officials labeled all six districts drought zones in 2010. Sumbawa, the province’s second principal island, also suffered severe drought in 2010, making it a province-wide problem.