This physical feature defines the critical areas in terms of slope and the risk of erosion. The map below shows the slope categories suitable for urban and non-urban development. These categories are discussed as follows:
Level to Nearly Level- areas with 0 to 3 percent slope. These areas comprise the Poblacion, portions of Barangays Wawa, Lumangbayan and Papandayan, Considering slope alone, these areas are normally part of the prime agricultural lands aside from being highly suitable for urban development.
Gently Sloping to Undulating– areas with 3 to 8 percent slope. The Rosario area resembles this type of terrain. According to slope characterization, these areas are still suitable for urban development and general agricultural production.
Sloping to Undulating lands – areas with 8 to 18 percent slope. These areas are quite susceptible to erosion. They are fairly suitable for intense urban development. Agricultural production, on the other hand, should be practiced with appropriate soil conservation techniques.
The undulating to rolling (18 to 30 percent), rolling to hilly (30 to 50 percent slope) to very steep (greater than 50 percent) areas are highly susceptible to erosion. Intense urban developments are not encouraged due to the instability of slopes. Agricultural activities should also observe soil conservation measures.