GEOGRAPHIC INFORMATION SYSTEM (GIS) MAPPING OF SOIL INFILTRATION (USING DOUBLE RING INFILTROMETER) IN BARANGAY SAN ISIDRO, GENERAL SANTOS CITY

The study aimed to determine the soil infiltration rate in Barangay San Isidro, General Santos City. The soil samples were taken from the agricultural areas where the soils are undisturbed and unshaded. The main objective is to generate a map of the instantaneous and cumulative infiltration of the area using QGIS 3.10 software. The data gathered in this study were the latitude, longitude, elevation, up-site weather, onsite temperature, moisture content, relative humidity, depth of water, instantaneous infiltration rate, and cumulative infiltration. The infiltration rate was determined using a double ring infiltrometer for every stage of instantaneous infiltration rate and cumulative infiltration. The weather during the field experiment and data gathering was sunny/cloudy. Based on the data gathered from 15 parcels, the highest and lowest instantaneous infiltration rate were found at Parcel J located near national highway Prk. Matatag and Parcel F in Guinto St. Prk. Malakas, with an overall average instantaneous infiltration rate of 331 mm/hr and 27 mm/hr, respectively. Also based on the data gathered, the highest cumulative infiltration were located also at Point J that has a value of 142 mm total depth of water infiltrated. While the lowest cumulative infiltration was found at Point C located at Lower Agan North Phase 4 with a value of 16.6 mm total depth of water infiltrated. Point J have more vegetation and less compaction which has more pore areas for water to infiltrate. Point F soil texture result was clay loam which means it has low water holding capacity. Point C is near to a canal which will make the soil easy to reach its field capacity and gives a low cumulative infiltration result. Overall, the results and values for the instantaneous infiltration and cumulative infiltration were mapped and the highest and lowest rate of soil infiltration in Barangay San Isidro, General Santos City were determined.