Laoag City has a total land area of 12,747.35 hectares or 127.4735 square kilometers distributed among residential, commercial, industrial, agricultural, bodies of water, roads and bridges, open spaces and other land uses of the 80 barangays of which 30 are urban barangays and 50 rural barangays. Of the total land area, 1,476.9909 hectares is occupied by the urban core on the poblacion while 11,270.3591 is being occupied by the rural barangays.
The central part of the city is predominantly lowland with a sloping terrain of five to ten feet above sea level. From the northeastern part of the city going west to Dibua are virgin hills diminishing in height from fifty two (52) feet to ten (10) feet above sea level.
Terrain / Relief / Water Surface
At the northeastern part of the city are hills and the highest peak located at Barangay Bacsil North in 183 feet above sea level. These hills are forested areas. Some portions of the central part of the city particularly the portion of Rioeng and Camanggaan along the river and Nangalisan are flood plains, their elevation being low and their location affected by the river’s water table on rainy seasons.
Land within the poblacion and all adjacent barangays and the rural barangays south of the river except Barangay Balatong, parts of Barangay Balacad and part of Bacsil and Lagui-Sail, coastal barangays of Barangays Calayab, Gabu, La Paz, Cataban and Caaoacan are level to very gently sloping, having a slope of 0-8% with a total land area of 8,699.19 hectares. These land are suited for prime agricultural farming and settlement. Barangay Pila, Dibua and part of Balatong, Balacad, Lagui-Sail and Barit have a slope of 8-18% with a land area of 3,019.364 hectares. These land are marginal agricultural land and is also suited for settlement purpose. Barangays Vira and Bacsil have a slope of 18-30% characterized as sloping to moderately steep. Those forest land has a total land area of 1,028.749 hectares with a slope of 30% and over.
The climate of Ilocos Norte, which includes Laoag City, is generally classified as belonging to the first type of Philippine climate. Characterized by two well-pronounced seasons; dry and wet and is classified as mild and pleasant climate. Dry season usually starts in November until April and wet during the rest of the year. The city is shielded from northeast monsoon and trade winds by the mountain ranges of Cordillera and Sierra Madre but it is exposed to the southeast monsoon and cyclone storms.
The rainy seasons, which has an average monthly rainfall of more than 100 mm. is from May to September with its peak in June, July and August. Rainfall during the peak month represents 68% of the annual rainfall with an average of 200 mm.
Temperature is very warm during the summer months and very cold during the cold months. In the afternoon of May, temperature reach up to 36.22 degrees centigrade and drops down to 24.4 degrees centigrade in the early mornings of January.
The city recorded an average temperature of 27.25 degrees centigrade with a relative humidity of 75.55% in 1996.The city experiences an average of four to five typhoons every year.
As per soil survey of Ilocos Norte, the soil types found in the City of Laoag are as follows:
Bantog Sandy Loam. The surface soil is brown sandy loam; friable; 25 centimeters thick. The subsoil is dark sandy clay loam to clay loam. The texture of this layer becomes finer as its depth increases. The substratum is yellowish brown silty clay loam. This type is found east of Barangay Apaya, Laoag City. The main crop is upland rice. Sugarcane is planted in small scattered patches. Other crops grown after rice are sweet potato, corn, tomato and eggplant. “Boho” grows in profusion at the foot of the hills,
San Manuel Loam. The surface soil is very pale brown to pale brown loam; loose and friable; 30 to 35 centimeters deep. Other profile characteristics are similar to those of the San Manuel Silt Loam.
San Manuel Silt Loam. The surface soil is coarse granular; and mellow when moist. The boundary with the lower layer is diffuse. The subsoil is pale brown silt loam to fine sandy loam with yellowish brown streaks; slightly compact. The lower limit of this layer is 90 to 100 centimeters from the surface. It is underlain by yellowish brown fine sandy loam to fine sand, which is slightly compact. The boundary with the lower layer is gradual.The San Manuel Loam soil type is found in the plains of Laoag City, Dingras, Sarrat, San Nicolas, Paoay, Batac and Pagudpud along the courses of rivers, and creeks. It is the most extensive soil of the plains.Lowland rice is the main crop grown although any crop in the locality can be planted on it. Corn, tobacco, garlic and mongo are usually planted after rice.In Laoag City, this type is devoted to vegetable gardening during the rainy season. Corn and mongo are intercropped after tobacco and garlic is harvested.
San Manuel Sandy Loam. The surface soil is very pale brown to brown sandy loam; loose and very friable; 25 to 30 centimeters deep. The boundary with the lower layer is diffuse. The subsoil is pale brown fine sandy loam, very friable. Its lower boundary is about 110 centimeters from the surface. This layer is undertaken by yellowish brown sandy loam to fine sand; loose and friable. The boundary with the upper layer is diffuse. This soil type was mapped as an irregular strip to land along Casili, Laoag. It was also found extending from Balacad to Cavit and Bascsil, Laoag.
San Manuel Silt Clay. The surface soil is silty clay; slightly sticky; 30 to 35 centimeters thick. It easily puddles and becomes hard when dry. The subsoil and stratum are more or less similar to those of other San Manuel Soils.This soil type is also found in Laoag and lowland rice is the main crop. Secondary crops are tobacco, garlic, corn and mongo.
Bantay Loam. The surface soil is brown to dark brown loam; friable; granular; and 15 to 20 centimeters deep. The boundary with the lower layer is granual. The upper subsoil is yellowish brown clay loam; friable; and coarse granular in structure. Beneath is a layer of highly weathered shale, which breaks into cube-like fragments under slight pressure. Lime precipitates are present. The substratum consists of highly weathered shale. This soil type occupied the rolling areas at the northern part of Laoag City.Like Bantay Clay Loam, this soil type is not agriculturally important. However, due to lack of arable land, these are cultivated and planted to sugarcane, Virginia tobacco and upland rice. Coconuts are also planted but are limited in number. Bamboo abounds in the area but a great portion is covered with brush and cogon.
Dune land. This is composed of coarse to medium, light gray to gray sand. It is characterized by an undulating to rolling topography. The greater portion of the land is unstabilized which means that strong winds induce sand movement.Although this land type has no agricultural value, this is found in the portion of the stabilized dune land in La Paz, Calayab, Apaya and Caaoacan, Laoag City. Certain portions are cultivated to sugarcane, cassava and sweet potato. These crops are stunted with native vegetation consisting of vines, grass and leguminous plants. “Kakauate”, kamachile, pandan and bamboo also abound in the stabilized sand dunes or dune land.
Rockland. This land type is composed of rocks, most of which are coralline limestone. In some places, there are very thin layers of soil materials on top of the rock unto which some plants have taken a foothold.A small area is found in La Paz, Laoag City.
San Fernando Clay. The surface soil is gray, dark gray to black massive clay; firm; sticky and plastic when wet, hard and compact when dry. The average depth is about 30 centimeters.The boundary with the lower layer is diffuse. The subsoil is dark gray to very dark clay; firm, sticky and plastic when wet. The depth of its lower boundary ranges from 50 to 70 centimeters from the surface. Beneath this layer is dark gray compact clay. The boundary with the upper layer is diffuse.This soil type is the second most extensive soil of the plains in Laoag City.This type is one of the best lowland rice fields. Although it is difficult to plow when dry, it is nevertheless utilized for Virginia tobacco after the rice crop is harvested. Wells are dug right on the farm as means for watering the tobacco plants.Also planted on a limited area are corn, garlic and sugarcane.
San Fernando Clay Loam. This type has the same profile characteristics as those of San Fernando Clay. They differ in the nature of their surface soil.San Fernando Clay loam consists of gray to very dark gray clay loam. It is slightly sticky when wet and slightly friable when moist. The San Fernando Clay is easier to till.This soil type is found in the strip of nearly level land east of the Laoag – Paoay provincial road southwest of Paoay Lake.The principal crop is rice. After which, the Virginia tobacco, garlic and onion, corn and mongo.
Flood Prone Areas
Barangays along the southern bank of the Laoag River; Barangays Nangalisan East and West, Nalbo, Zamboanga and Cavit.
Southern portion of the Barangay #29 in the urban area (poblacion) that is adjacent to the northern bank of the Laoag River;
A portion of Brgy. Rioeng (eastern part of the city) adjacent to the Laoag River along its northern bank;
Barangay #01 San Lorenzo at the southwestern part of the urban area (city proper/poblacion) and rural barangays of Santa Maria and Casili; and
Barangays along the Mangato Creek particularly Apaya and Araniw.