How do the mountain ranges shape the east and west coasts of New Caledonia?

Rugged mountain ranges, primarily composed of metamorphic rock, divide the main island of New Caledonia into two distinct coastal environments.1

• East Coast: The mountains descend precipitously to the sea in many areas. This side of the island is subject to trade winds, resulting in high annual precipitation of approximately 120 inches (3,000 mm) and the growth of forests.12
• West Coast: The terrain slopes more gradually, characterized by broad, undulating plains and steep-sided hills. Because the mountains act as a barrier to the prevailing winds, this side is significantly drier, receiving less than 40 inches (1,000 mm) of rain annually, which supports the development of savannas.123

The central mountain chain also influences the island's drainage; numerous streams flow toward the lagoon, though they are prone to rapid flooding after rainfall and often dry out during dry weather, particularly on the west coast.1