MEGASAINS Bulletin is published by Global Atmosphere Watch (GAW) Bukit Kototobang as a media to appreciate scientific papers sourced from research activities based on the meteorology, climatology, air quality, geophysics, and the environmental sciences. p-ISSN: 2086-5589 e-ISSN: 2723-2239
Stasiun Pemantau Atmosfer Global Bukit Kototabang
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STUDY OF THE RELATIONSHIP BETWEEN THE DISTRIBUTION OF THE 26 DECEMBER 2004 ACEH AFTERSHAKE AND THE DISTRIBUTION OF COULOMB STRESS CHANGE
During the last few years, scientists have been focusing on studying the interaction between the aftershocks distribution and the change of coulomb stress, as well as the interaction between one major earthquake and other earthquake events, which were closely located. The aim of this paper is to examine the distribution of aftershocks of Aceh earthquake on December 2005 from the changes of coulomb stress pattern. The main earthquake data, along with rupture parameters, were treated as the inputs for analyzing the coulomb stress change, with the help from a software package, Coulomb v3.3. The results showed that 49.8% of the aftershocks of the Aceh earthquake on 26 December 2004 is distributed on the areas where positive coulomb stress change were calculated, whereas the rest is located on the negative change
Copyright (c) 2013 Megasains https://creativecommons.org/licenses/by-nc/4.0
RATIO OF UV, PAR AND NIR COMPONENTS TO GLOBAL SOLAR RADIATION IN KOTOTABANG HILL, 2012
This study discussed about the relationship between three components of solar irradiance (Ultra Violet (UV), Near Infra-red (NIR) and Photosynthetically Active Radiation (PAR)) and global irradiance measured at Bukit Kototabang in 2012. The relationship was carried out by calculating the ratio between global irradiance and each of the solar irradiance components, as well as by determining the correlation coefficient values. The results indicated that the approximation of global solar irradiance components is 5% UV, 55% NIR and 45% PAR. Also, the ratio between UV and global solar irradiance suggested that the water vapour content in Bukit Kototabang is relatively high
THE RELATIONSHIP BETWEEN EARTHQUAKES AND VOLCANO ERUPTIONS CASE STUDY OF MOUNT SINABUNG ERUPTION IN 2010 AND 2013
Volcanic activity is inseparable from seismic activities and tectonic conditions in the surrounding area. The aim of this paper is to investigate the relationship between earthquakes and volcanic eruptions. The results indicate that after the Mw9.0 Aceh earthquake in 2004, followed by subsequent large aftershocks, has produced positive Coulomb stress changes in the region. Those changes have triggered the disruption of Mount Sinabung in 2010, which has been inactive for four centuries. The cross section that divided Mount Sinabung before the eruption in 2013 also showed positive changes in the Coulomb stress at the lower part of Mount Sinabung, up to a depth of 85 km with lobes up to 5 x 10-3 bars
DETECTION OF CLIMATE CHANGE FROM MONTHLY RAINFALL DATA IN WEST KALIMANTAN
A study to detect climate change using monthly rainfall data from 59 observation points in West Kalimantan has been carried out. Mann-Kendall statistical tests and Sens methods were used in this study. The trend values were shown in the form of spatial maps using Inverse Distance Weighted (IDW) interpolation method. The results showed that West Kalimantan has a bimodal rainfall pattern (two peaks rain), with the first peak occurs in April, followed by the second peak in December. The annual rainfall in most areas of West Kalimantan showed a significant downward trend in the range of 1-70 mm/year. Rainfall in the dry months (June and July) increased significantly by 1-10 mm/month in most areas. Contrastingly, during the wet period (March, May and November to January), rainfall has significantly decreased in most regions, especially in the south and west part
RAIN PAUSE (DRY SPELL) AND RAINFALL BASED ON PROBABILITY IN DRY LAND TYPOLOGY IN LOMBOK
Dry spells and the probability of precipitation are very essential for both rainfed and dry land agriculture. The parameters are important indicators of drought status and have relevance to crop risk in dry land areas. The research objective is to determine duration of dry spells and probability-based rainfall in the area of climate types D and E at southern Lombok. Descriptive research was conducted in 2014 by collecting daily rainfall data from 13 rainfall stations. The station are assigned as purposive sampling to represent the southern part of Lombok area. Conditional upon the nature of the incident rainy day or day without rain was analyzed using Markov chain model of level one, using daily rainfall data of 16 years. Probability of precipitation was determined using the formula of transformation in order to meet the normal curve distribution properties. Drought-level assessment carried out based on the value of the standard precipitation index (Standard Precipitation Index, SPI) using growing season rainfall data of span 30 years. The results show, that the dry spells and probability-based rainfall varies spatially and temporally as well as influenced by variations in standard precipitation index; dry sells was longer getting to the east, and rainfall decreased. Dry spell is parabolic; always longer in the early (November) and the end of the growing season (April), and relatively short in between. Dry spell on SPI-negative was longer than the SPI-positive. The nature of the growing season tends to a dry nature, with level of mild drought
Copyright (c) 2015 Megasains https://creativecommons.org/licenses/by-nc/4.0
THE IMPACT OF CLIMATE CHANGE ON METEOROLOGICAL DROUGHT AND THE AGROCLIMATIC SUITABILITY OF CORN IN WEST NUSA TENGGARA PROVINCE
Climate change was predicted will afect on drougth and food crops suitability including mays as one of priority commodities in West Nusa Tenggara (NTB). However study on this matter has not been conducted previously. This paper describes the results of the study on Climate change impact on meteorological drougth and mays agroclimate suitability in West Nusa Tenggara. The study carried out since July 2014 to January 2015; using down scalling data from regional Conformal Cubic Atmospheric Model (CCAM_CSIRO) with 14 square kilometer resolution. This data was utilised to calculate the areas affected by meteorological drugth using Standardized Precipitation Index (SPI) method and mays agroclimate suitability in the future. The results of the study indicate that there is variation in rainfal as well as temperature in two different periodes. Rainfall decrease about 30% - 40% in mid future (2040-2069) and about 10% - 20% in the future (2070-2099). Unlikely, temperature is predicted to increase about 1,1°C - 1,6°C in mid future and 2°C - 3,2°C in the future. This condition is predicted will affect the area which experience meteorological draugth in the mid future, wher about 22% - 29,4% become very drauth meanwhile very wet area decrease about -17,39%, therefore corn agroclimate suitability is also predicted wil dereasing significantly. Mays agroclimate suitability level S1 decrease 5,3%; S3 decrease 10,5%; and N (not suitable) decrease about 54,7%. Contraditory, suitability level S2 increasing significantly about 74,8% in the mid future and in the future relatif to baseline data 1971- 2000
SENSITIVITY OF CUMULUS AND RADIATION PARAMETERIZATION CONFIGURATION IN THE WRF MODEL IN THE GROWTH PROCESS OF CUMULONIMBUS CLOUDS DURING THE 2012-2013 TRANSITION SEASON AT JUANDA CLASS I METEOROLOGICAL STATION, SURABAYA
Cumulonimbus (Cb) is kind of dangerous cloud, especially for aviation. Lifting process of water vapour to be Cb is generally a characteristic of convective cells by a strong updraft due to solar insolation or moisture content. Because of cumulus and radiation parameterization is important in developing Cb, so that we need to know the most appropriate configuration scheme in WRF model at Juanda Meteorology Station when the season transition. Cumulus parameterization is used as much as 3 scheme (KF, BMJ, and GD), longwave radiation parameterization is used as much as 2 scheme ( RRTM and CAM), and shortwave radiation one is used as much as 2 scheme (Dudhia and Cam). So the total of scheme’s configuration are 12 schemes. Using uniform and stepwise method, we get that KFCAMCAM is the most appropriate scheme that its result has many similarities with observation data
CLOUD TO GROUND (CG) LIGHTNING STROKE PATTERNS RELATED TO RAINFALL IN THE REGION OF ACEH Besar DISTRICT, BANDA ACEH
This paper describes the relationship between CG (Cloud to Ground) lightning with the rainfall in Aceh Besar. Aceh Besar has a lightning-prone areas because it has topography that allows the growth of convective clouds around the mountain. Lightning disasters can manifest as lightning attack can be fatal whoever who comes into direct contact with it. The danger caused by a lightning strike is so great, so so people need to be aware if there is rain accompanied by lightning. This study aims to determine how the relationship of lightning to rainfall patterns based on data collected over three years. This study was conducted using lightning data obtained in Aceh Besar of Geophysics Mata Le Station and rainfall data from the Meteorological Blang Bintang Station. The data used is CG lightning occurrence data in Aceh Besar during three years period 2009-2011 and the data of rainfall over 50 mm/day in Aceh Besar. Data analysis is determine relationships CG with rainfall. It is used the Microsoft Excel 2007 software. The results of the study showed the linear relationships between CG with rainfall. Relationships of the data during 2010 to DJF (Desember-January-February) with r = 1.0, MAM ( March-April-May) with r = 1.0, JJA (June-July-Augst) with r = 1.0 and SON (September-October-Nopember) with r = 0.9609
COMPARISON OF MEASUREMENT OF PHOTOSYNTETICALLY ACTIVE RADIATION (PAR) DIRECTLY AND INDIRECTLY IN A SHORT PERIOD AT SPAG BUKIT KOTOTABANG
This study was conducted to compare the results of measurement of PAR (Photosyntetically Active Radiation) between the direct and the indirect method in the Global Atmospheric Watch (GAW) Bukit Kototabang Station. Direct measurements was performed by PAR Radiometer sensor which is one of instrumentation AAWS (Agroclimate Automatic wheather Station). Indirect measurement using empirical equations which are output of the three instruments, namely QPSP-Eppley Pyranometer (IGlo), RG58-Eppley Pyranometer (INIR) and Total UV Radiometer (ITUV). The magnitude of the intensity of PAR (IPAR) empirically defined IPAR = IGlo- (INIR + ITUV). The comparison showed that the results of the calculation (indirect measurement) higher than the results of observations (direct measurement)
MAPPING THE POTENTIAL THREAT OF LANDSLIDS IN NORTH SUMATRA PROVINCE
Initiation of potential hazard mapping of landslide movement in northern Sumatera becomes the main priority in disaster mitigation. Mitigation of landslide is expected to decrease and avoid the impact of landslide movement disaster. Concrete steps to anticipate improper land usage can be done by mapping its potential hazard. Disasters may arise as a result of human activities (anthropogenic) and natural factors. Approachment to the triggering factors is done by overlaying and scoring the parameters that trigger the landslides movement. Based on its statistical approach, we can conclude that North Sumatra province has the potential of landslide movement. The lowest potential of landslide movement is 5,94 % ; lower potential 74,23 % ; middle potential 19,52 % and the highest potential is 0,03% from the total area ofthe province of North Sumatra
ANALYSIS OF VARIABILITY AND CLIMATE CHANGE ON THE AGROCLIMATIC SUITABILITY OF SOYBEAN IN WEST NUSA TENGGARA PROVINCE
West Nusa Tenggara (NTB) established by the government as one of the national soybean production centers to pursue self-sufficiency target of producing one million tons of soybeans per year. Soybean demand nationally and locally increase from year to year. Beside (El Nino / La nina), climate change will lead to increased frequency of weather / climate extremes, droughts, extreme rainfall. Climate change in West Nusa Tenggara will certainly have an impact on agro-climatic suitability of soybean area. By utilizing the regional climate model data Conformal Cubic Atmospheric Model (CCAM) resolution of 14 km of the Climate Change Adaptation Project Collaboration UNRAM-CSIRO, the data used to create the climate projections then used to classify of soybean agro-climatic suitability based FAO standard. The decline of annual rainfall average in future periods and the increase in the temperature average of 20 to 30 ºC baseline period to 23-32 ºC in future. Analysis of agro- climatic suitability class for soybean crops in NTB projected to significant changes with less extensive suitability class S1 (Very Suitable) decrease by 3.0%, the class of S3 (Marginal Suitable) decrease 12.5% and the class N (Not Suitable) decrcrease 9.2 nevertheless occur the increase in class of S2 (Suitable) of 24.7% both in (2040-2069) and (2070-2099) relative to the baseline period (1981-2010).
SIMULATION OF STRONG WINDS AT LOMBOK INTERNATIONAL AIRPORT USING THE WRF MODEL ON MARCH 15 2012
On March, 15th 2012 a strong winds occured in Lombok International Airport (BIL). The wind blowing at a speed over 35 knots at 14.00 pm until 15.00 pm where it is very disturbing the airlines activities and also damaging the infrastructures in the airport. To illustrate the strong winds in BIL and to know the reliability of the model, then the simulation with methods observation and experimental by WRF-ARW version 3.1 had to do. In this study, radiation scheme was tested toward wind speed to get the best scheme. After that, running the FNL data by the best scheme and also for the GFS data prediction to get the output to be analyzed. WRF-ARW output showed indicate that strong winds that occurred on March 15, 2012 in BIL due to a low pressure area in the South Indian Ocean of Lombok Island. The result showed that the best radiation scheme is RRTM-Dudhia with correlation value is 0,5 and RMSE value is 5,4. The model can illustrated the strong wind event very well, that can be seen by the output of the model either FNL or GFS data don’t have a big difference value with the observation data.The wind speed of the model is about 40 knots that almost same as the observation data.
CHANGES IN THE STATIC COULOMB STRESS OF THE DOBLET EARTHQUAKE AND ITS INFLUENCE ON THE ERUPTION OF THE BATUR VOLCANO IN 1963
Batur Eruption in year 1963 was the interesting phenomenom due to 4 months prior the eruption there were near doublet earthquake. The aim of this paper is to investigate the relationship between earthquakes and volcanic eruptions. These results indicate that the earthquake on May 18th 1963 resulted a positive Coulomb stress changes (0.05 bar) in the direction of the Batur Volcano, and the earthquake on May 22th 1963. The cross section that divides Batur volcano and doublets earthquake showed the positive Coulomb stress changes to the lower part of Batur volcano in the depth range of 30-70 km with lobes reaching 0.05 bar. When compared with the results of tomographic imaging, the Coulomb stress changes are positive in the partial melting region of Batur volcano
EVALUATION OF AUTOMATIC CALIBRATION RESULTS ON CO ANALYZER HORIBA APMA 360 AT SPAG BUKIT KOTOTABANG PERIOD 2012-2015
Research has been conducted to evaluate the results of automatic calibration the instrument CO Analyzer HORIBA APMA 360 at GAW Bukit Kototabang Station in period 2012-2015. Automatic Calibration is done by automatic zero and automatic span check check. Automatic zero check is done by entering the dry air free of carbon monoxide (CO) into the instrument. Automatic Span check is done by mixing the standard gas carbon monoxide (CO) concentrations of 44.86 ± 0:45 ppm with dry air free of carbon monoxide (CO) using a dilution unit into the instrument. Results of automatic zero check indicates there has been a deviation value of the concentration of CO from 2013 to 2015, while the automatic span check results show that most of the CO concentration values are far below the theoretical value (443 ppb)
EARTHQUAKE RISK LEVEL IN THE NORTH SUMATRA REGION
The maximum ground acceleration is the largest ground acceleration recorded in the region due to the earthquake. The value of risk of earthquake ground acceleration is needed to be considered as part of the planning of earthquake resistance building. Risk is the product of hazard multiply by vulnerability which the result depend on both factors. Disaster potential is the ground acceleration factor, while the vulnerability is a total population factor. Using historical earthquake data from USGS in North Sumatra which located at 1ºS - 5ºN and 96.5 - 100,5ºE, period from 2005 to 2014 calculated the maximum ground acceleration with formula Boore (1997). The value is 372.5 gal. Medan and Deli Serdang have the largest population of the North Sumatra Province, it is referring that the greatest risk produced by the greatest vulnerability factor
AN ASSESSMENT OF ENSO BASED PREDICTIVE SYSTEMS IN INDONESIA
The use of Seasonal Climate Forecasting (SCF) in risk management decisions in the developing countries such Indonesia, which are most vulnerable to the impacts of climate variability and climate change, has not been widely applied yet. The major limitations are; the limited national capacity for climate monitoring and forecasting; low levels of awareness among decision makers to the local and regional impact of climate variability (e.g. ENSO); and lack of effective policy responses to climate variability and climate change. The specific objectives of this study are, for each main climate regions of the Indonesia, analyse the relationship of seasonal rainfall with key ENSO based predictors and determine the most “robust” predictive system(s) for each these region. To use FLOWCAST software to undertake three methods of investigation. Results of regression and contingency table analyses show that the synchronous associations between SOI, NINO 3.4, SST and Indonesia rainfall are significantly stronger in all climate zones for 2 seasonal periods selected (May – October and November – April) in Monsoonal and Local Type. The strength of this relationship also corresponded to high forecasting skill (LEPS) being found especially in Monsoonal and Local Climate Type of Indonesia, with the influences effecting Monsoonal
Measurement of UVB solar radiation at Kototabang Hill period January-December 2015
Monitoring of UVB irradiance flux on the Earth’s surface is one of Global Atmosphere Watch Bukit Kototabang Station programs. The station has operated UVB radiometers for monitoring UVB irradiance flux. Result for the period of 2015 showed diurnal variation for UVB Irradiance achieved their maximum at around 12 LST noon irradiance was around 5,5 Wm- 2.Meanwhile, for daily variation of UVB irradiance, maximum occurred on February 20th, minimum on February 18th. For the monthly variation of UVB irradiance, maximum occured on February, minimum on October. UVB irradiance has positive linier correlation with Global irradiance
Copyright (c) 2016 Megasains https://creativecommons.org/licenses/by-nc/4.0
WRF-Chem model projections of air quality and atmospheric conditions in West Sumatra
WRF-Chem is a form of WRF (Weather Research and Forecasting) that combined with chemistry calculations, which could be used for emission, transportation, mixing, and transformation simulation from gases and aerosols meteorogically. This study uses two parameterization that are PBL10 (TEMF Scheme) and PBL99 (MFR Scheme), which is compared with observation data from meteorological office Tabing Padang for wind speed data and from GAW Kototabang for carbon monoxide data. The results are PBL99 produced a better prediction model data for wind speed data, although it still need further research to decide which parameterization is suited for modeling in Padang
Determining the normal rainy season in Indonesia based on the frequency of basic rainfall
Generally climatologists decide a climatological normal from a 30 years average of climate elements. BMKG also use the same method to generate climatological normal for onset of season, using the average of each decadal (10 days) rainfall cumulative in 30 years period. In this assessment climatological normal for onset of season is determined by the frequency of 50 mm rainfall for each decadal. The result is then compared to the climatological normal from decadal rainfall average. Generally the conclusions of this assessment are: with the frequencies distribution the central tendency of climatological normal for the onset of season periodically are look more clearly than climatological normal by the average, then the climatological normal generated by frequency method gives smaller deviation of actual season onset and the dry season period by frequency is longer than using the average method
Sumatra has a tectonic system be interesting, because there are subduction system which resulted in below the Sumatran mainland there are 19 fault segment that extends from Banda Aceh to the Sunda Strait. The purpose of this study is to determine the value of seismic activity (a) and the value of the fragility of the rock (b) in each segment along the Sumatran fault, using the Gutenberg-Richter earthquake database BMKG and ISC (International Seismological Center) from start till 01-01-1964 31-05-2012. Segment Aceh Barumun and has a value of a = 4809 and 4770, the highest compared to other segments below the Sumatran mainland these, a highest value of this means Barumun and Segment Aceh has the highest level of seismic activity, while Segment Sumpur and Sianok in West Sumatra have b values were low at 0237 and 0382. The low value of b clearly illustrated by the seismic zone gap in this region. The lowest b value means the value of the smallest vulnerability so as to have a fairly high elasticity and capable of storing large stress, before being released as an earthquake. So Sumpur and Sianok segment is a segment that needs to be watched, because the rocks on this segment could at any time have the potential earthquake with enormous power. Making research sites in each segment Sumatra fault because this region is megathrust and the surface has a lot of settlements, which is expected to know the location that has a high seismic activity and a low value fragility rocks, can be used as a reference for the purposes of mitigation in the region
Utilization of Landsat 5 satellite imagery to analyze the May 2008 landslide incident in Paya Ateuk Village - South Aceh
This paper discusses the use of Landsat 5 multitemporal satellite imagery to analyze land cover changes in due to landslide in Paya Ateuk sub-district Aceh Selatan province in May 2008. Satellite images data used are 2007 and 2009. Change vector analysis (CVA) and image differencing method with component analysis greenness, brightness and wetness and components vegetation index NDVI, BI and NDWI is use in this journal. It is known that land cover changes due to landslides can be detected using image differencing method and the CVA method, CVA method can be used to stratify various types of land cover changes due to landslides. Using multispectral classification NDVI component, known that the open land area due to landslides is 1,170 m2, with landslide avalanche length is 1,823 m, at the slope of 25-40% to > 40%
Rain lag (dry spell) and probability-based rainfall on dry land typology in Lombok
Dry spell and probability of precipitation are very essential for both rainfed and the dry land agriculture. The parameters are important indicators of drought status and have relevance to crop risk in dry land areas. The research objective was to determine duration of dry spells and probability-based rainfall in the area of climate types D and E at southern Lombok. Descriptive research was conducted in 2014 by collecting daily rainfall data from 13 rainfall stations. The stations were assigned as purposive sampling to represent the southern part of Lombok area. Conditional upon the nature of the incident rainy day or day without rain was analyzed using Markov chain model of first order, using daily rainfall data of 16 years. Probability of precipitation was determined using a formula of transformation in order to meet the normal curve distribution properties. Drought-level assessment was carried out based on the value of the standard precipitation index, SPI using growing season rainfall data of span 30 years. The results show, that the dry spells and probability-based rainfall varied spatially and temporally as well as they were influenced by variation in the standard precipitation index; dry spell was longer getting to the east, while rainfall decreased. Dry spell was parabolic in nature; It is always longer in the early growing season (November) and at the end of the season (April), and It was relatively short in between. Dry spell on SPI-negative was longer than that on SPI-positive. The characteristic of the growing season tends to be getting drier, with a level of mild drought over all.
The Influence of El Niño and La Niña on Rainfall in Biak for 30 Years (1981-2010)
Research on the influence of El Niño and La Niña during 30 years is focused in Biak. Rainfall data (1981-2010) is based on Biak Meteorological Station observation. ENSO activity and its teleconection to the variability of monthly rainfall has been evaluated by analyzing the response of the monthly rainfall and ENSO-related activities through the comparison of normal monthly rainfall and ENSO events composites. At the time of El Niño, Biak monthly rainfall tends to decrease until it reaches 42.55% which took place in October. While, La Niña tends to leave positive impact on Biak monthly rainfall of up to 54.27%, which occurred in September. The influence of El Niño and La Niña most to the seasonal rainfall occurs in the SON or transition period from dry to rainy season. Correlation analysis between Biak monthly rainfall and Niño 3.4 index during the period reveals that ENSO activity gives negative impact on Biak monthly rainfall with the highest correlation coefficient occurred in October, reaching -0.55. This number indicates that correlation is strong enough
DYMEX Simulation for Estimating Potential Risk of Yield Loss by Yellow Rice Stem Borer Pest in Indramayu
Yellow Rice Stem Borer (YSB) is a major pest in rice plants that have a high enough intensity of attacks in area of rice production centers, especially in West Java. Climate is one of the environmental external factors which influenced the pattern of population dynamics. The purpose of this study is to develop a climate information system through simulation models DYMEX in order to reduce risk of yield loss level in rice production by YSB pest in Indramayu area, West Java. Estimation risk of yield loss can be predicted from the results of YSB pest population dynamics modeling with requires climate parameters input and YSB development under threshold of temperature (To) to describe YSB life cycle from eggs, larvae, pupae to adult (imago) phase. Calibration and validation test of models showed the coefficient of determination (R2) between model predictions results and observations in the study area is well, which can illustrate the development, mortality, transfer of individuals from one stage to the next life also fecundity and YSB reproduction. Climate information that can be provided from a data model output shows the development of imago phase will more quickly reproduce on high temperature conditions and low rainfall intensity so able to trigger the larvae development rate that can damage rice plants at various stages. Thus, the potential rice yield loss can be well predicted through YSB population dynamics modeling
Climatological Study of the Singkawang Flash Flood May 21-22 2016
Publications of several local media in West Borneo mentioned that occurred the flood event at Singkawang on May 21st-22nd, 2016 due to perforated Semelagi levee. Heavy rainfall allegedly caused the increasing of water discharge in Semelagi riverbank, it caused the perforated levee. This flood event reported that a village settlement in 1724 Ha wide submerged, it also effected the transportation access agitated. This study was conducted to comprehend the type of flood occurred, and also the causative factors. To investigate this case, conduct the climatological research by using rainfall data of 8 locations at Sambas regency (Selakau, Salatiga); Bengkayang regency (Ledo, Sanggau Ledo, Sei Duri) dan Singkawang city (West Singkawang, Centre Singkawang, East Singkawang). The data used were 3 days data (May 21st, 22nd, 23rd, 2016). This research was conduced by using case study method and qualitative approach with took topography into consideration. Known the heavy rainfall which were more than 50 mm/day occurred in almost all of locations and this condition affected to the significantly increase of water discharge in Semelagi river (considered that Semelagi has the lowest elevation). Heavy rainfall was reported as the effect the atmospheric condition (such as : the lower of OLR, SOI that near to La Nina phase, the cloudiness, and the higher of rainfall anomalies). Finally, known that Singkawang flood was categorized to Flash Flood. By conducting this research, public may consider to build the settlement far from riverbanks
Study of Spatial Variations of Seismotectonic Parameters to Determine Local Tectonic Stress Conditions and Seismic Activity Levels in West Sumatra and Surrounding Areas
Spatial variations of seismotectonic parameters. a and b values ??can describe tectonic stress conditions and the level of seismic activity in an area. a and b values ??are the level of seismic activity and seismotectonic characteristics in an area. A low a value reflects a low level of seismic activity and vice versa for a high a value, while a low b value can reflect high local tectonic stress conditions and vice versa for a high b value. In this study, using catalogs from the BMKG and NEIC/USGS, the observation period was 1 January 1973 – 31 December 2010 with coordinate boundaries of 2 North Latitude – 4 South Latitude and 94 East Longitude – 104 East Longitude covering the area of ??West Sumatra and its surroundings. To determine spatial variations in seismotectonic parameters using ZMAP software (Wiemer and Wyss, 2002). From the analysis, it was found that the spatial variation of b-value ranged from 0.6 – 2.0 and the a-value ranged from 4 – 11. High local stress conditions (low b-value) were observed around the Mentawai Islands, the southern part of Nias Island and along the hills of West Sumatra and Low local stress conditions (high b-value) were observed in the west-northwest of Nias Island and along the northern Sumatran hill range. Meanwhile, low levels of seismic activity occur in the Mentawai Islands and high levels of seismic activity occur in the west-northwest of Nias Island and along the hills of the northern part of Sumatra.
Spatial variations of seismotectonic parameters
The Influence of the Southern Surge on Rainfall in the Nusa Tenggara Region East In January 2007
The region withmonsoonal type has rainfall peak on January. However, on January 2007, monsoonal type region has negative anomaly, it means that there is a decresing rainfall. Based on research of Taryono (2012), southerly surge activity influenced to the decreasing of rainfall of monsoon break phase at Java island. Therefore, this research was conducted to understand the relation between southerly surge activity to the decreasing of rainfall in January 2007, especially at East Nusa Tenggara.Southerly surge index was conducted by calculating the variance of daily average meridional wind during January 1980-2010, therefore found the surge indices 11,5 m/s. In January 2007 occurs 2 phenomena of shouterly surge on January, 3rd and 11th 2007. The result both of those days show that the decresing of rainfall in East Nusa Tenggara caused by southerly surge activity which is replacing monsoon through Nortward, therefore causes the decreasing of rainfall in East Nusa Tenggara as the effects of the restrained of moist air from Northen hemispere and the coming of dry and cold air from Shoutern hemispere
Verification of Solar Radiation Energy Calculations Using Methods Prescott Regarding Actual Conditions
Sun radiation is the source of energy that can give effect processes in atmosphere. Different with energy drom fossil, sun radiation is profuse energy but it depend on astronomical location. Indonesia as a country in tropical area that accept so many energy of sun radiation, so Indonesia is a potential place that can be used to using sun radiation as a source of energy. But, because of the limited of information about sun radiation in Indonesia,the profit of energy of sun radiation cannot be used maximally. So we need a formula that can be used to calculate energy of sun radiation to complete the data based on another available data. Calculation of sun radiation with Prescott method is a method that can be used to calculate energy of sun radiation based on duration of sunshine and latitude data. But, we need to know how suitable calculation with Prescott method and actual condition is, so the result data can be used maximally. Based on the comparation of calculation of sun radiation with Prescott method and actual condition, both of them have the same pattern that is showed by the high value of correlation in some places that is in Kayuwatu, Kototabang, Banjarbaru, Maros and Pondok Betung, in other side Pulau Baai has different pattern that is showed with low value of correlation but it has the lws value of Root Mean Square (RMSE) so the different value is can be tolered
ACID RAIN IN CITEKO BOGOR AND KEMAYORAN JAKARTA
Using data on sulfate ions and nitrate ions collected at air quality observation stations in Citeko, Puncak Bogor and Kemayoran, Central Jakarta from 1993 – 2012, we have calculated the deposition of acid using the cation and anion analysis technique from water samples using the ion chromatography method. . The Citeko region which is in the peak region of Bogor has been exposed to acid rain. Acid deposition in Citeko averages 10.5 meq/m2/month equivalent to 5.04 kg/ha/month with a range between 6.11 – 13.03 meq/m2/month. In Kemayoran, the average monthly acid deposition is 8.5 meq/m2/month or equivalent to 4.08 kg/ha /month with a range between 5.15 - 15.2 meq/m2/month. In both locations, the type of acid deposited is a large contribution of sulfuric acid, 69.9% respectively in Kemayoran and 64.9 in Citeko. In Kemayoran, sulfuric acid is deposited more than in Citeko. Nitrate is deposited more a lot in Citeko than in Kemayoran. Based on monthly and normal annual windrose data in Citeko, it is possible that there has been transport of SO2 and NO2 pollutants from DKI Jakarta, Depok, Tangerang and surrounding areas to the peak area of ?? Bogor. Local wind vectors (sea-land breeze) also play a role in bringing pollutants to the Citeko area in Puncak Bogor
ANALYSIS OF AIR QUALITY PARAMETERS IN 2015 SMOG CONDITIONS IN WEST SUMATRA
Analysis of air quality during the period when the haze occurred in the West Sumatra region in October 2015 was carried out to determine the level of concentration of air quality parameters on public health at that time. The analysis was carried out using data measured at GAW Bukit Kototabang Station on the parameters PM10, CO and SO2, then the haze dispersion was analyzed using the Hysplit application and verified with the wind field pattern. From the results of the analysis of data parameters, it was found that the haze that occurred during this period was the worst haze in the last 5 years. Smoke haze has a direct effect on increasing concentrations of PM10 and CO gas, while on the SO2 parameter there is no indication of a significant influence. The haze that occurs in the West Sumatra region comes from hotspots in the provinces of South Sumatra and Riau which causes air quality to reach a "dangerous" level for health. This is shown in the PM10 parameters, while the CO and SO2 gas parameters are still in "good condition".