Verification of Weather Predictions Using Voluntary Weather Observations Via WhatsApp and Google Forms During the Dry Season 2021

The weather data that can be obtained through government institutions is very limited, whereas in order to increase the accuracy of weather predictions a homogeneous and dense distribution of data is needed. Therfore it is necessary to increase the data and the purpose of this research is to create a simple and effective way to encourage the number of weather observations in Indonesia through the STMKG Weather Care program. Forms that are made as easy as for respondents to understand, simple, and don't take the time. Developed using Google Form and distributed via the most popular social media today, namely WhatsApp. The test results showed that social media has the potential to be used to support voluntary weather data. The form made is sufficient so that the respondents make relatively few mistakes in terms of the main content of the form. Moreover, the mistakes that are often made by respondents include filling in ID, and typing sub-districts that require manual correction. Based on the results of voluntary observations spread in almost all provinces of Indonesia with the most incoming data coming from the provinces of Central Java and East Java. Based on the evaluation results of 4 months of testing, weather variations and their predictions can be identified with an accurate distribution, with an average accuracy of 0.79. Differences in methods used in verification may affect accuracy

The Values of Natural Disaster Mitigation in Discourse: The True Story of the Acehnese Tsunami Victims

This article aims to investigate the values of natural disaster mitigation among Acehnese Tsunami Victims. Natural disaster mitigation is an important issue for people who live in disaster-prone country such as Indonesia. Hermeneutical approach was employed in this study to reveal the values of disaster mitigation contained in the book about true story of the survivors of the Earthquake and Tsunami that occurred on December 26, 2004. The results of this research indicate that there are eighteen values of natural disaster mitigation, with details of 9 mitigation values about what to do when a tsunami occurs, 3 mitigation values about what should be avoided, and 6 mitigation values about preventive measures to reduce tsunami risk. Finally, this research reveals that these empirical facts can corroborate the theories and concepts of mitigation of the Earthquake and Tsunami disaster and also as reference to various educational context

A Green Economy Approach to Solid Waste Management in Minna, Nigeria

This study is based on solid waste recycling activities in Minna, Nigeria. This study examines the potential for waste recycling to provide livelihood opportunities in Nigeria. The study identified two recycling centres in Minna and collected data through direct observation, measurements, questionnaire administration, and interviews. The collected data was analyzed using statistical packages for social sciences and livelihood approach to demonstrate the green value of recycling, identify impediments to green growth, and map the recycling cluster. The result shows that the recycling cluster occupies an area of 0.64 hectares that accommodates 141 recycling outlets, with about 40% of the outlets occupying below the standard shop size of 7.2m2. The recycling outlets use 18 types of recovered materials to reproduce 27 varieties of products. Each recycling outlet engages about 3.4 persons and offers training to an average of 6 persons each. The study highlights the importance and potential of informal solid waste recycling as a sub-sector that fulfils social, economic, and environmental benefits associated with sustainable development. However, the lack of commitment by governments to waste recycling undermines the contribution of the recycling business. Moving towards the zero-waste policy can save public funds that can be invested in the waste disposal and reduce the threat to public health from solid waste. Furthermore, safety measures should be ensured among the scavengers and the recyclers, and the physical environment of the recycling cluster should be upgraded to take care of poor accessibility and the use of makeshift structures by most of the recycling units. Governments should focus on policies that encourage waste sorting, collection, sales, and solid waste processing at all scales. We underscore the need for creative and reliable government support to achieve green growth and development in the solid waste recycling sector

Predisposition Factor of Safety of Landslide Dams from Typhoon Talas, Kii Peninsula, Japan

Landslide dams are less frequent than other landslides, and their very existence is often very-much short-lived, because the temporary dam tends to collapse rapidly. Because of the resulting lack of evidences, there has been less research done on this topic, although the potential catastrophe they can be at the origin of needs assessment. For this purpose, the present contribution aims at differentiating landslides that trigger dams against those that do not inside a group of valleys of the Kii peninsula in Japan, where landslides occurred af-ter the typhoon Talas in 2011. Using topographic map before the event and LiDAR data in its aftermath, the authors have calculated the factor of safety (FS) of different landslides in the same valleys, comparing the da-ta of landslides that created dams against those that did not. The results show that landslides that triggered dams seemed to have a higher FS than those that did not. The authors suggest that it is because larger land-slides are needed and thus appear more stable, but also because at the location where the slopes are stable, the riverbed can incise further instead of growing horizontally, and thus the sediments damming the channel have more chances to block it (as it is narrow) and stop the river from flowing

Spatial Analysis of Mangrove Distribution Using Landsat 8 Oli in Badung Regency and Denpasar City, Bali Province, Indonesia

Bali is an island situated among the Indonesian archipelago with huge potential to host mangrove forests. Using remote sensing technology advances, satellite images, such as Landsat images, might be employed to analyse mangrove forest distribution and density. This paper presents an analysis of mangrove distribution in Badung Regency and Denpasar City, Bali, as a basis for the management and conservation of mangrove ecosystems. This study used Landsat 8 OLI images and a vegetation index to analyse the mangrove forest distribution and density in this area. It started by identifying mangrove forests using the RGB 564 band and continued to distinguish between mangrove and non-mangrove objects using unsupervised classification, before analysing mangrove density using the NDVI formula. The results show that the mangrove forest area in 2020 was 1,269.20 ha, with an accuracy rate of 83%. Mangroves were found on the deepest or most curved coastline of the Benoa Bay area, on enclosed waters. This distribution follows the river network in the lower reach, which has thick deposits and is uninfluenced by large currents and waves. Based on the vegetation index analysis results, the mangrove forest area observed mainly had a moderate density, with a total area of 510.85 ha (40%), followed by high density (413.15 ha/ 33%) and low density (340.51 ha/ 27%)

Participatory GIS Approach to Assessing Building Vulnerability to Tsunamis in Pangandaran Regency

Some cities in Indonesia which are located on Southern Java Island are susceptible to tsunamis. However, the application of participatory GIS for the assessment of building vulnerability to tsunamis remains rarely evaluated. The aims of this research are 1) to obtain the parameters of building vulnerability to tsunamis using the participatory approach, and 2) to evaluate the results of building vulnerability assessment using participatory GIS. A tsunami inundation map was constructed based on numerical modelling using the Hawke's Bay equation. Participatory approaches were taken to establish the parameters that affect the vulnerability of buildings to tsunamis using in-depth interviews. Respondents were selected using the purposive sampling technique. A geographic information system (GIS) was then applied to build a geodatabase and to perform analysis. The results show that six parameters were obtained from local people’s participation, namely building materials, the number of stories of the buildings , orientation, preservation condition, building row, and natural barriers. All the parameters were identified and interpreted using aerial photos. A field survey was conducted to complete the information on building characteristics. Many buildings near the beach were classified as having high and moderate vulnerability. The main benefit of participatory GIS is that the role of the community makes a significant contribution to providing vulnerability information. It also raises public awareness and improves preparedness for disaster risk management. The drawback is that parameters based on participatory approaches are dynamic and may be different in other areas

Identification of Andesite Resource Potential In Kalirejo Area, Kokap Sub-District, Kulon Progo Using Resistivity Method

In the last five years, the need for materials to build infrastructure in Kulon Progo Regency has increased with the construction of an international airport. In the construction process, strong earth or rock materials are needed to make buildings resistant to earthquakes, one of which is andesite rock. This study aims to determine andesite rocks' resources using a three-dimensional model based on the value of resistivity in Kalirejo district Kokap Kulon Progo. The research was conducted by geological and geophysical survey. Based on data on the distribution of rocks in the research area included in the intermediate igneous rocks, andesite. These rocks are intrusions that develop in research areas. Petrography analysis is used to determine the types of minerals in andesite rocks and determine which levels of rock changes have changed or not to affect the strength of rocks. These rocks are intrusions that develop in research areas. Geophysical survey is by resistivity method using configuration dipole-dipole with five lines, and each stretch is 200 m. Based on three-dimensional model resistivity, fresh andesite is at a depth of between 5-10 m. Value of andesite resistivity is more than 668 Ωm, while the value of weathered andesite resistivity ranges from 256-536 Ωm and andesite resources about 332,580 tons

Forensic Profiling Analogue Approach for the Investigation of Natural Hazards – A Case Study from Onokoba Elementary School, Unzen Volcano, Japan

Internal temperature variations of pyroclastic flows and their deposits are arguably the most challenging data to acquire. As a preliminary study of the temperature variation inside pyroclastic flows, the remains of Onokoba Elementary School (Shimabara, Japan) were investigated. The elementary school is located in the close vicinity of Unzen volcano and was hit by one of the largest pyroclastic flows during the latest active period of the volcano on 15th of September 1991. This present preliminary study aims to determine the temperature exposure of various portion of the school building using field-forensic and urban geology. Natural hazard methods applied to the damaged materials exposed to high temperature have generated a temperature fingerprint the maximum temperature distribution. Charred wooden parts and plastic gutters installed on the schoolyard-side faced of the building turns out to be the most useful temperature indicators. The various deformation and alterations of the studied materials show significant differences in the temperature exposed to. Such differences on the second-floor section (between 75-110°C and 120-150°C) and on the first-floor section (above 435-557°C) of the building do not simply imply significant temperature heterogeneity in short distance (some ten to ≤100 m) inside the pyroclastic flow, but also points toward the possible effects of the building architecture on some key dynamic parameter of the pyroclastic flow. Such information may be important for planning future hazard mitigation actions

Spatial Analysis on Tsunami Predictions in Pandeglang Regency

Pandeglang Regency is an area that has the potentiel to be hit by tsunamis. The plate subduction paths of Indo-Australia and Anak Krakatau Volcano make Pandeglang Regency a region with a high tsunami potential. One step that can be taken to overcome and minimize losses is to do spatial planning to protect it against potential tsunami damage. This research aimed to evaluate the spatial area of Pandeglang Regency based on the identification of potential tsunami hazards.  The concept of modelling the tsunami inundation height developed by Berryman and based on Head Regulation No.4 of 2012 of the Indonesian National Board for Disaster Management has been used to identify potential tsunami hazards. The modelling was carried out by calculating the potential distribution of tsunami wave heights in coastal areas.  Three scenarios were used to estimate the distribution. The results showed that the first scenario predicted a maximum tsunami height   of 7.5 meters above sea level with the furthest tsunami inundation reaching 1,700.12 meters. Second scenario predicted maximum height of 15 meters, with the furthest tsunami inundation reaching 3,384.62 meters. Meanwhile, the last scenario was able to predict a height of 20 meters and showed the furthest tsunami inundation reaching 5.155,11 meters. These results proved that in all scenarios, the widest inundation would occur in Panimbang Regency. This is due to the relatively small variations in roughness and slope of the surface. The same condition also occurs in the last two scenarios, in which Sumur District was the area most ffected. Therefore, the spatial plan of Pandeglang Regency needs to be evaluated and the function of residential area changed to reduce and prevent large losses

Erosion Analysis in the Mrica Reservoir Catchment Area in Indonesia using the Soil Erosion Status Method

The reservoir catchment area (RCA) of Mrica in Banjarnegara district is a powerplant in Central Java with a capacity of 184.5 MW. Mrica Dam, also called the dam of Great Commander General Sudirman, has seen its functions gradually decrease due to sedimentation from massive erosion that has occurred in the upland regions. RCA Mrica, with the upland area in Wonosobo district, has an area of 93,546.4 hectares, consisting of six sub-watersheds, Lumajang, Serayu upstream, Begaluh, Serayu, Tulis and Merawu. In 2017, sedimentation in the dam reached 238,236,588.20 m3/year, resulting from an erosion rate of 524,948.33 tons/year. In light of this serious erosion problem in the Mrica RCA, this study aims to estimate the distribution of the erosion level, categorised as slight, moderate and severe, using the SES (soil erosion status) formula. SES was calculated by mapping the level of each influential aspect: aspect, drainage, land cover, slope and soil texture. The calculation used SRTM (Shuttle Radar Topography Mission) satellite imagery and 2017 Landsat TM7 images. The results show slight erosion (50 tons/ha/year) in 1,468.7 ha (1.6%); moderate erosion (50-100 tons/ha/yr) in 56,258.8 ha (60.1%); and severe erosion ( 100 tons/ha/year) in 35,818.9 ha (38.29%). Sampling in the field took into account the slope class of nine classes and was repeated three times, so the number of samples taken in the field was 27. From field visits to the 27 location points, there was conformity in the results of the sensing analysis is much more than 85%”.  The results of the erosion calculation using the SES method showed severe erosion of 27.9% (26,137 ha); moderate erosion of 70.2% (65,679 ha); and slight erosion =of 1.8% (1,731 ha).  Further erosion calculation using the SES method needs to be compared with calculation using other methods