Abstract.A team of scientists from New Zealand and Indonesia undertook a reconnaissance mission to the South Java area affected by the tsunami of 17 July 2006. The team used GPS-based surveying equipment to measure ground profiles and inundation depths along 17 transects across affected areas near the port city of Cilacap and the resort town of Pangandaran. The purpose of the work was to acquire data for calibration of models used to estimate tsunami inundations, casualty rates and damage levels. Additional information was gathered from interviews with eyewitnesses.The degree of damage observed was diverse, being primarily dependant on water depth and the building construction type. Water depths were typically 2 to 4 m where housing was seriously damaged. Damage levels ranged from total for older brick houses, to about 50% for newer buildings with rudimentary reinforced-concrete beams and columns, to 5-20% for engineered residential houses and multi-storey hotels with heavier RC columns. "Punchout" of weak brick walls was widespread. Despite various natural warning signs very few people were alerted to the impending tsunami. Hence, the death toll was significant, with average death and injury rates both being about 10% of the people exposed, for water depths of about 3 m.

Abstract. Sari N, Patria MP, Soesilo TEB, Tejakusuma IG. 2019. The structure of mangrove communities in response to water quality in Jakarta Bay, Indonesia. Biodiversitas 20: 1873-1879. The waters of Jakarta Bay, which is a habitat for mangrove vegetation, have been polluted caused by many human activities such as development of housing, industry, tourism and facilities along the coast, and reclamation of man-made islands. The islands reclamation has caused changes in ocean current pattern and has impacts on material mobilization in the waters. The mangroves have experienced degradation as well since long time ago. The purpose of this research was to investigate the responses of mangrove vegetation to the quality of water in disturbed areas in Jakarta Bay to be used as baseline information for mangrove forest management in the area. Analysis of vegetation was used to examine mangrove community structure with the results were then related to the measurements on water quality using simulation modeling. The results show that mangrove forests in Jakarta Bay have an average Important Value Index (IVI) for all levels of life stage 95.7% with relative density of 28.85%, relative frequency of 29.21%, and closure relative of 38.62%. These results indicate that the mangrove forests in Jakarta Bay are under the criteria of damaged or disturbed according to the Minister of Environment Regulation. The mangrove forests were dominated by Avicennia marina, Avicennia lanata, Rhizophora apiculata, Sonneratia caseolaris, and Sonneratia alba. The average of ocean current velocity was 0.04-0.08 m/s. tides were single type with short waves generated by wind. The water discharge from 13 rivers were 205 ± 97 m3/s and the water discharge from power plant 224.9 m3/s. The heavy metal whereas The average pH was 7.75; Dissolved Oxygen 4.68 mg/L; turbidity 5 m; Total Suspended Solid (TSS) 50.95 mg/L; and salinity 6.6 ‰. The result of grain size analysis showed that most sediments obtained was in the form of silt with a mixture of little clay and sand. The responses showed that there was a reinforced pattern for pH, temperatures, rainfall, brightness, sediment, DO, and ocean current, with a trend of exponential growth in two years next of important value index of mangroves in response to water quality in Jakarta Bay. The heavy metals of Pb have concentrations of 65-104 ppm in sediments and 38-60 ppm in the water column; Zn has 150-258 ppm in sediment and 42-140 ppm in water column; Cu has 34-72 ppm in sediment and 13-30 ppm in water column; Ni has 33-39 ppm in sediment and 40-50 ppm in water column; Cd has 5.9-8 ppm in sediment and 8.5-15 ppm in the water column. The heavy metals, TSS, and water river discharge have balance-decay pattern. The amount of river water discharge entering Jakarta Bay, the heavy metals, and the low level of ocean currents cause coastal waters of Jakarta Bay to become muddy puddles that cannot flow properly. These conditions make the mangrove forest habitat becomes polluted and the mangrove vegetation degraded. Therefore, all of these things need to get serious attention so the mangrove forests can be restored and the function of mangroves can return to normal.

Flood disaster is one of predominant disaster event in Indonesia. The frequency and intensity of this disaster tend to increase from year to year as well as the losses caused thereby. To reduce the risks and losses due to flood disasters, innovation in disaster mitigation is needed. Artificial intelligence and machine learning are technological innovations that have been widely applied in various fields of life and can also be used to improve flood disaster mitigation. A literature study conducted in this research shows that the use of artificial intelligence and machine learning has proven to be able, and succeed to fastly and accurately perform flood prediction, flood risk mapping, flood emergency response and, flood damage mapping. ANNs, SVM, SVR, ANFIS, WNN and DTs are popular methods used for flood mitigation in the pre-disaster phase and it is recommended to use a combination or hybrid of these methods. During the flood disaster response phase, the application of artificial intelligence and machine learning are still not much has been done and need to be developed. Examples of the application are the use of big data from social media Twitter and machine learning both supervised learning with Random Forest and unsupervised learning with CNN which have shown good results and have a good prospect to be applied. For the use of artificial intelligence in post-disaster flood phase, are still also rare, because it requires actual data from the field. However, in the future, it will become a promising program for the assessment and application of artificial intelligence in the flood disaster mitigation.

The Chilean tsunami of 22 May 1960 reamed out a breach and built up a fan as it flowed across a sparsely inhabited beach-ridge plain near Maullín, midway along the length of the tsunami source. Eyewitnesses to the flooding, interviewed mainly in 1988 and 1989, identified levels that the tsunami had reached on high ground, trees, and buildings. The maximum levels fell, from about 10 m to 2 m, between the mouth of the tidal Río Maullín and an inundation limit nearly 5 km inland across the plain. Along this profile at Caulle, where the maximum flow depth was a few meters deep, airphotos taken in 1961 show breaches across a road on a sandy beach ridge. Inland from one of these breaches is a fan with branched distributaries. Today its breach holds a pond that has been changing into a marsh. The 1960 fan deposits, as much as 60 cm thick, are traceable inland for 120 m from the breach. They rest on a pasture soil above two additional sand bodies, each atop its own buried soil. The earlier of the pre-1960 sand bodies probably dates to AD 1270-1400, in which case its age is not statistically different from that of a sand sheet previously dated elsewhere near Maullín. The breach likely originated then and has been freshened twice. Evidence that the breach was freshened in 1960 includes a near-basal interval of cobble-size clasts of sediment and soil, most of them probably derived from the organic fill of pre-1960 breach. The cobbly interval is overlain by sand with ripple-drift laminae that record landward flow. The fan of another breach near Maullín, at Chanhué, also provides stratigraphic evidence for recurrent tsunamis, though not necessarily for the repeated use of the breach. These findings were anticipated a half century ago by description of paired breaches and fans that the 1960 Chilean tsunami produced in Japan. Breaches and their fans may provide lasting evidence for tsunami inundation of beach-ridge plains. The breaches might be detectable by remote sensing, and the thickness of the fan deposits might help them outlast an ordinary tsunami sand sheet.

Coastal Vulnerability Index (CVI) was used to analyse the physical vulnerability to coastal disaster of the coastal areas of Makassar City. CVI will consider six variables namely geology, geomorphology, erosion and accretion, tidal range, average wave height and elevation. Geologically, coastal areas of Makassar comprise sand, gravel, clay and coral limestone. Geomorphologically, alluvial plain, sandy to gravelly beaches are predominant in the coastal areas. Both erosion and accretion occurred in the coastal areas in which accretion predominantly found in the southern part whereas erosion in the northern part of the city. Using Digital Elevation Model it can be observed that the elevation of the coastal areas of Makassar City is between 0 -0.5 meter which is very vulnerable to sea level rise. Average tidal range was between 1.1 to 2 meter and wave height between 0 to 2.9 meter. CVI analyses showed that the coastal areas of Makassar City is vulnerable to sea level rise and hence to the coastal disaster. In addition, according to the analyses, Wajo, Biringkanaya and Tamalanrea districts are very vulnerable to sea level rise and coastal disaster. Coastal development planning in these very vulnerable areas will need special attention and specific measures.