Land Subsidence Monitoring 2016 - 2018 Analysis Using GNSS CORS UDIP and DinSAR in Semarang

Land Subsidence is phenomena likey common and occurred due to natural cause, loading, and geological setting. In the coastal area land subsidence became worse, cause influence by sea-level rise, The impact land subsidence can lead to wider expansion (flooding area called rob), damage or cracking construction/building and large of maintenance cost. Semarang is the capital city in Central Jawa have experienced in land subsidence in several decades. The north of Semarang was reported a higher rate of land subsidence compared with the south. It was believed that the land subsidence areas were affected by young alluvium, ground extraction and a load of the building. To anticipate, land subsidence should be monitored and detected in an early stage. The most effective way of monitoring land subsidence using GPS, DInSAR to evaluate the characteristic of land subsidence. The GPS observation was conducted in 2016 – 2018 using CORS UDIP as a base station and Sentinel Data was conducted to analyzed the subsidence rate in Semarang. The result showed land subsidence rate in several areas was distributed both spatially and temporally