Rainfall frequency analysis in Indonesia using spatial approach (original) (raw)
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Journal of Measurements in Engineering
In a period of ten years, from 2011-2020 rainfall in Indonesia is relatively high, with annual rainfall between 460.5-4,627.4 mm. The high rainfall has implications for flooding in several provinces. During this period, almost every year several areas in Banten Province experienced floods. To predict areas of Banten Province that have the potential for flooding, forecasts of rainfall and the potential for repeated occurrences of high rainfall are carried out. In making the forecast, observations were made at the Serang Meteorological Station, the Budiarto Curug Meteorological Station, the South Tangerang Climatology Station, and the Tangerang Geophysics Station. Rainfall data from the four stations were analyzed by Fourier transform, Gumbel method and Mononobe method. Distribution analysis results obtained rainfall in Banten Province between 0.0-607.9 mm with the length of rainy days per month between 0-26 days. Then, the results of the Fourier transform analysis; Banten Province in...
Spatial pattern of rainfall events:a background study to modeling and forecasting rainfall
2014
The study of extreme rainfall events and their spatial coverage is important in identifying areas with high and low extreme events. It has been widely known that extreme rainfall is responsible for major flash flood and landslide events that have caused significant loss of life and economic losses. Unfortunately, the dynamics of extreme rainfall events still received less concern. This study scrutinized the characteristics of extreme rainfall and their spatial coverage in Peninsular Malaysia using rain gauge data. Eight indices of climate extremes based on daily precipitation data defined and adopted by the Joint Expert Team on Climate Change Detection and Indices (ETCCDI) were calculated. The selected indices captured the precipitation intensity, the frequency and length of heavy rainfall events. The geostatistical method of Ordinary Kriging (OK) is applied to the indices calculated. The results from OK method give a pictorial representation of the structure of extreme rainfall spa...
Exploratory Analysis of Rainfall Occurrence in South Sulawesi Region Using Spatial Point Process
Journal of Mathematics and Statistics, 2015
This paper study the probability of rainfall occurrence in round year in different segment in South Sulawesi region. In this research, rainfall occurrence in round year described by one line which has divided into 12 months. Each one of those months is assumed that the probability of a rainfall follow a homogeneous Poisson distribution. To modeling the rainfall occurrence in round year, a spatial point process is used. The parameter of the model is estimated by Seemingly Unrelated Regression (SUR) method and Ordinary Least Square (OLS) method with assume that two stations have a correlation in residual model. Results of case study on monthly rainfall data indicate that when the residual correlation (autocorrelation) on all models is weakly and not significant. Thus, it has not good enough to use the SUR method for increase efficiency compared with the OLS method. Moreover, results of the parameter estimation of the model for two selected stations (Paotere and Mandai) showed that the SUR method is more representative than the OLS method.
Spatial Coherence and Predictability of Indonesian Wet Season Rainfall
Journal of Climate, 2001
Rainfall from 63 stations across Indonesia is examined for the period 1950-98 to determine the spatial coherence of wet season anomalies. An example of almost unrelated anomalies at two neighboring stations is presented. Principal component analysis is used to quantify the spatial coherence across the entire region. The significant components show high loadings over only a small region, suggesting that rainfall in only this small region varies coherently on an interannual timescale. Correlation with the Southern Oscillation index (SOI) shows that rainfall over only this same region is being largely governed by the El Niño-Southern Oscillation (ENSO) phenomenon. In contrast, a similar analysis for the transition season (Sep-Nov) rainfall shows coherence across almost the entire region and a similarly large area of high correlation with the SOI. Results for all seasons are summarized with the use of an all-Indonesian rainfall index constructed from an averaged percentile ranking of seasonal rainfall from each station across the region. At the times of the year when a large (small) percentage of the variance of rainfall is described by the lowest-order principal components, there is a large (small) correlation between the SOI and the all-Indonesian rainfall index. The implication is that wet season rainfall in Indonesia is inherently unpredictable.
Rainfall Seasonality Index for South Sulawesi Province, Indonesia, 1982-2012
2015
Spatial and temporal variability of rainfall for any region in the world are very important with regards to planning for various sectors including water supply and agriculture demands. The aims of this paper are to study the spatial and temporal variability of seasonality of rainfall and its relation to rainfall regimes within the South Sulawesi Province, Indonesia. Data for the 64 rainfall stations for the 29 years (1983 – 2012) were used in order to calculate the SI for the whole of the South Sulawesi area. In general, the result showed that the dominance SI was the seasonal rainfall regime of 0.60 to 0.79 especially in the central region of the South Sulawesi. Furthermore, the rainfall regimes of rather seasonal with a short drier season (0.40 – 0.59) and markedly seasonal with a long drier season (0.80 – 0.99) were calculated for the northern part and Western part of the South Sulawesi Province, respectively. One significant finding was that the entire province did not experienc...
Spatiotemporal Characteristics of Extreme Rainfall Events over Java Island, Indonesia
Extreme rainfall event is one of natural events frequently generating serious impact to many sectors. To date, its characteristic is expected being changing due global climate change. The study was aimed to identify the spatiotemporal characteristics of extreme rainfall events over Java Island, Indonesia by focusing analysis to East Java Province.
Article Spatial-Temporal Variation and Prediction of Rainfall in
2014
In Northeastern Nigeria seasonal rainfall is critical for the availability of water for domestic use through surface and sub-surface recharge and agricultural production, which is mostly rain fed. Variability in rainfall over the last 60 years is the main cause for crop failure and water scarcity in the region, particularly, due to late onset of rainfall, short dry spells and multi-annual droughts. In this study, we analyze 27 years (1980-2006) of gridded daily rainfall data obtained from a merged dataset by the National Centre for Environmental Prediction and Climate Research Unit reanalysis data (NCEP-CRU) for spatial-temporal variability of monthly amounts and frequency in rainfall and rainfall trends. Temporal variability was assessed using the percentage coefficient of variation and temporal trends in rainfall were assessed using maps of linear regression slopes for the months of May through October. These six months cover the period of the onset and cessation of the wet season throughout the region. Monthly rainfall amount and frequency were then predicted over a 24-month period using the Auto Regressive Integrated Moving Average (ARIMA) Model. The predictions were evaluated using NCEP-CRU data for the same period. Kolmogorov Smirnov test results suggest that despite there are some months during the wet season (May-October) when there is no significant agreement (p < 0.05) between the monthly distribution of the values of the model and the corresponding 24-month NCEP-CRU data, the model did better than simply replicating the long term mean of the data used for the prediction. Overall, the model does well in areas and months
International Journal of Climatology, 2003
The characteristics of climatic rainfall variability in Indonesia are investigated using a double correlation method. The results are compared with empirical orthogonal function (EOF) and rotated EOF methods. In addition, local and remote responses to sea-surface temperature (SST) are discussed. The results suggest three climatic regions in Indonesia with their distinct characteristics. Region A is located in southern Indonesia from south Sumatera to Timor island, southern Kalimantan, Sulawesi and part of Irian Jaya. Region B is located in northwest Indonesia from northern Sumatra to northwestern Kalimantan. Region C encompasses Maluku and northern Sulawesi. All three regions show both strong annual and, except Region A, semi-annual variability. Region C shows the strongest El Niño-southern oscillation (ENSO) influence, followed by Region A. In Region B, the ENSO-related signal is suppressed. Except for Region B, there are significant correlations between SST and the rainfall variabilities, indicating a strong possibility for seasonal climate predictions. March to May is the most difficult season to predict the rainfall variability. From June to November, there are significant responses of the rainfall pattern to ENSO in Regions A and C. A strong ENSO influence during this normally dry season (June to September) is hazardous in El Niño years, because the negative response means that higher SST in the NIÑO3 of the Pacific region will lower the rainfall amount over the Indonesian region. Analyses of Indonesian rainfall variability reveal some sensitivities to SST variabilities in adjacent parts of the Indian and Pacific Oceans.
Temporal and spatial characteristics of rainfall in Kuala Lumpur, Malaysia
Atmospheric Research, 1996
Knowledge of temporal and spatial characteristics of rainfall in Kuala Lumpur, Malaysia is still lacking and they are still considered important for more efficient management of the implemented urban water resources projects. In view of this, a study was conducted to characterise the historical rainfall phenomena (from 1982 to 1992). Statistical properties of annual, monthly, and minutes rainfall were derived. Spatial correlation fields for the annual and monthly rainfalls were studied. The results showed that the temporal and spatial characteristics of rainfall in this region were pronounced, even on the basis of two groups of monthly rainfall. Thus they give the basis for further understanding of rainfall processes in Kuala Lumpur region and, in general, in humid tropics.
Spatio-temporal climatic change of rainfall in East Java Indonesia
International Journal of Climatology, 2008
Spatial and temporal rainfall analysis of the Brantas Catchment Area (DAS Brantas), East Java, from 1955 to 2005 based on 40 rainfall stations with monthly rainfall data derived from daily rainfall data has been performed. To identify the climatic trend and annual changes in the area over the last five decades, we use the empirical orthogonal function (EOF) method based on multivariate statistics, followed by the fast Fourier transform (FFT) method for the power density spectrum analysis, the non-parametric Mann-Kendall trend test and the wavelet transform method. With EOF, we found the monsoonal rainfall pattern as the most dominant in this area, which explains about 72% of all variances. Without the annual signal, the leading EOF shows significant ENSO-modulated inter-annual and seasonal variabilities, especially during the second transitional period. We found a common and significant negative trend of accumulated rainfall and a negative trend of the monsoonal strength and dominance. This finding leads to changes in the annual pattern, which are increase in the ratio of rainfall during the wet season and increase of the dry spell period or the imbalance of the annual pattern. The increased ratio of the rainfall in the wet season has led to an increased threat of drought in the dry season and extreme weather in the wet season in recent decades. The role of the orographic effect had been detected from the decadal pattern, in which the high-altitude areas have greater rainfall amount all year round. From the decadal isohyets in December/January/February (DJF) and June/July/August (JJA), the rainfall amount decreased significantly during the last five decades as shown by a persistent increase of areas with low rainfall amount. By comparing the time series of rainfall data in two locations, the mountain and coastal areas, we discovered that the dry periods have increased, mainly in the low altitude area. Copyright © 2007 Royal Meteorological Society