Mapping the critical level of water infiltration areas in the western of Mijen sub-district, Semarang City, Central Java

Semarang City as the capital of Central Java Province is the main destination for urbanization in the Central Java region, which causes population density in Semarang City to increase, resulting in the development of land functions that can interfere with water infiltration areas. The western sub-district of Mijen, Semarang City, which is located on the border of Semarang City with Kendal Regency, and Semarang Regency, has also become a place for land use development due to the dense urban area. From these problems, research was conducted on the criticality of water infiltration areas in the western part of Mijen Subdistrict in order to be taken into consideration by the government to make policies. This research uses primary data in the form of soil and lithology mapping, and secondary data in the form of land use and slope, which are then verified in the field. The data were analyzed using the AHP (Analytical Hierarchy Process) method by creating a pairwise comparison matrix on each parameter, and subparameter, which was then overlay. The western part of Mijen Sub-district has a good level of criticality of water infiltration areas located in parts of Wonoplumbon Village, Ngadirgo Village, Tambangan Village, and a small part of Cangkiran Village. Naturally normal conditions and starting to be critical are relatively evenly distributed throughout the research area. Slightly critical, critical, to very critical conditions are located in the center of Wonoplumbom Village, north of Ngadirgo Village, and south of Cangkiran Village, and Bubakan Village.