この辺りは陸地が少なく、ほとんど海だ。
There is little land around here; it's mostly sea.
陸地 refers to land area, the direct opposite of 水域, which refers to a water area.
陸地 refers to land, the opposite of 海域, which refers to an area of sea.
land area
Compound of 陸 (riku, 'land') and 地 (chi, 'ground, earth'). The reading is on'yomi for both characters.