The water catchment area also indirectly impacts on flood control for areas that are lower than it because rainwater does not fall to the lower areas but is absorbed as groundwater. Increased development of Padang City will be inversely proportional to the reduction in water catchment areas and become an area that is impermeable that makes rainwater stagnate on the surface and flood occurs. The development of remote sensing technology and geographic information systems has made it possible to study the spatial patterns of potential water catchment areas in a wide range, including mapping the potential of water catchment areas in Padang City. This study aims to analyze the condition of the availability of water catchment areas for controlling water management and flood disasters in Padang City based on data on spatial parameters such as rainfall data, slope, soil type maps, and land use obtained from Landsat 8 OLI imagery data. This study uses the scoring and overlay method with the Geographical Information System. The results show that the condition of the water catchment area in the western part of Padang City have been critical, reaching 18.29% of the total area of ​​Padang City, this is due to land use that has undergone a change of function. If the water infiltration condition worsens (critical), it gives more opportunities for flooding and inundation. Thus the areas with the potential for water absorption which are categorized as critical and very critical in the research location can be said to be areas that are potentially prone to flooding and inundation, because the ground surface is no longer able to absorb water. Monitoring the potential of water catchment areas is one form of flood mitigation efforts.

Padang City is the capital city of West Sumatra Province which is located on the west coast of the island of Sumatra which is generally associated with tectonic earthquakes. This condition causes the city of Padang to become a disaster-prone area, one of which is land surface changes. The earthquake that occurred caused shocks to the rock and soil layers, causing water below the earth's surface to come out and resulting in changes to the soil surface. Besides, changes in soil surface are also caused by several things, including excessive groundwater extraction and soil type factors. To reduce the bad impacts, it is necessary to monitor the ground surface and to reduce the risk of a disaster. In a broad scope, the use of SAR imagery using the DinSAR method can monitor changes in the land surface in the city of Padang. The data used were Sentinel -1A imagery based on 3 earthquakes with a strength of more than 5 magnitudes centered on the Mentawai Islands, on September 8, 19, and 21 October 2020. From this research, the results obtained from the earthquake 8 September 2020 with satellite recording data 28 August (slave) and September 9, 2020 (master), there was land subsidence with a range of 0 - 25 mm along the coast of Padang City. The 19 and 21 October 2020 earthquakes with satellite recording data of 27 October 2020 (slave) and 15 October 2020 (master) obtained almost even surface subsidence with a range of 0 - 40 mm throughout the residential area of ​​Padang City.

Bukittinggi city is in the sink segmentation "semangko" fault line, which causes Bukittinggi City to frequently experience earthquakes. From 2019 to 2020, there have been at least 9 earthquakes above 5 on the Richter scale. DInSAR is a radar imaging method that utilizes phase, amplitude, and wavelength in its processing to obtain topography and land surface changes. This study has three aims. This research shows that the earthquake from 2019 to 2020 uses 18 pairs of sentinel-1 image scans recorded in 2019-2020 and uses DEM SRTM 30, namely the earthquake that happened on February 2, 2019, in the sub-district of Guguak Panjang with a range of 1 – 45 mm. The smallest increase occurred in the sub-district of Guguak Panjang and Mandiangin Koto Selayan, with a length of 1 mm on November 11, 2019. The most significant reduction happened in the sub-district of Aur Birugo with -22 mm. In contrast, a less substantial reduction occurred in the sub-district of Guguak Panjang with -5 mm on October 8, 2019. The Modified Mercalli intensity scale for earthquakes in 2019-2020 uses the measure of Donovan's parameters demonstrated by numbers 2, 3, and 4. Number 2 indicates that resting people feel the earthquake's strength, especially hanging, shaking, and vibrating on the second floor. Number 3 represents the vibrations of passing trucks, windows, doors, and glassware clashing and making noises