IDENTIFYING SUITABLE AREAS FOR SMALL FARM RESERVOIR IN AGUSAN DEL NORTE USING GEOGRAPHIC INFORMATION SYSTEM
Keywords: Geographic Information System, Small Farm Reservoir, rainfall harvesting, irrigation, suitability mapping
Abstract. The Philippines, as a part of Southeast Asia, falls into the zone categorized with agricultural areas prone to drought. Mitigating the concerns due to such vulnerability and also catering the needs of small-time farmers, rainfall harvesting with the use of agricultural structures called Small Farm Reservoirs (SFRs) used for storing water for irrigation are being used and deployed. This study aims to identify ideal locations for SFR which is essential due to the concerns of its geographical appropriateness and its vulnerability to environmental and other concerns such as seepage, sustainability, and optimizing yield. Geographic Information System through the ArcMap software is a modern tool for decision making, especially in the concerns of suitability and vulnerability assessment and was used in creating the suitability map for SFR in this study. The suitability map was created with the use of pre-processed raster data sets for precipitation, soil texture, slope, irrigation status. Weights for the weighted overlay were acquired from the standardized protocol for Small Scale Irrigation Project (SSIP) standardized protocol for site suitability identification from the Department of Agriculture - Bureau of Soil and Water Management (DA-BSWM) Philippines. Existing SFRs in the study area were validated through site visitation and were evaluated for usability and performance. The suitability map created accurately identified suitable zones for establishing SFRs with a result of 7 out of 7 existing SFRs are within the suitable zones, six (6) sites in the moderately suitable and one (1) on marginally suitable.