scholarly journals Pengaruh Perubahan Iklim terhadap Hidrograf Banjir di Kanal Banjir Timur Kota Semarang

2016 ◽  
Vol 22 (2) ◽  
pp. 119 ◽  
Author(s):  
Suripin Suripin ◽  
Dwi Kurniani
Keyword(s):  
Climate Change ◽  
Water Level ◽  
Return Period ◽  
Daily Rainfall ◽  
Annual Rainfall ◽  
Water Runoff ◽  
Rainfall Characteristics ◽  
Flood Water ◽  
Flood Discharge ◽  
Flood Hydrograph

East Flood Way is one of the rivers in Semarang City that often cause flooding. Flood water level in the East Flood Way is affected by the discharge of storm water runoff and tide (rob). Facts on the ground indicate that the flood water level in the canal tends to increase from year to year. One possible reason is the increased flood discharge associated with climate change, besides the impacts of land use changes. This study aims to analyze the impacts of climate change on rainfall characteristics and their effects on flood hydrograph in the East Flood Way. The study begins with the collection and analysis of historical rainfall data to get a change of rainfall characteristics over time. The flood hydrograph was then analysed by HEC HMS. The results showed that in the period of last 30 years annual rainfall and maximum daily rainfall tended to increase of 22.64 mm / year and 2.56 mm / year consecutively, while the number of rainy days tend to decrease of 4 days / year. As a result of changes in the characteristics of the rainfall, the flood discharge of East Flood Way is expected to increase in the range between the 15.10 m3/s (31.5%) for 2-year return period up to 32.28 m3/s (25.5 %) for 200-year return period.

scholarly journals ANALISIS TINGGI MUKA AIR BANJIR DAS BELAWAN DENGAN MENGGUNAKAN SOFTWARE HECRAS

2018 ◽  
Vol 7 (1) ◽  
pp. 26-29
Author(s):  
Asril Zevri
Keyword(s):  
Water Level ◽  
Cross Section ◽  
Return Period ◽  
Industrial Development ◽  
Daily Rainfall ◽  
Flood Water ◽  
Flood Discharge ◽  
Flood Level ◽  
Maximum Daily Rainfall ◽  
River Cross Section

Abstract: Belawan River Basin is one of the watershed, which currently change the land use because of the increasing population and industrial development. Rainfall with high intensity can cause rapid runoff, causing flood around the plains of the river cross section. The purpose of this research is to determine the flood water level of Belawan Watershed and flood discharge return period. Scope of activity in this research is analyzing daily rainfall Belawan watershed with the flood-discharge return period. Scope of activity in this research is analyzing maximum daily rainfall Belawan Watershed, and simulating flood water level with HECRAS. The result of the study shows that the potency of Belawan watershed flood water level is caused by flood discharge at 25 to 100 years especially in the middle to downstream of river cross section that is between 0.7 m and 3.3 m. Keywords: Flood Discharge, Flood Level, Belawan Watershed, Software HECRAS. Abstrak: Daerah Aliran Sungai Belawan adalah salah satu DAS yang pada saat ini mengalami perubahan tata guna lahan seiring bertambahnya jumlah penduduk dan perkembangan industri. Curah hujan yang tinggi dapat mengakibatkan limpasan sehingga menimbulkan tinggi muka air banjir di sekitar dataran penampang sungai. Tujuan dari penelitian ini adalah untuk mensimulasi tinggi muka air banjir DAS Belawan dengan debit banjir periode kala ulangnya. Lingkup kegiatan dalam penelitian ini yaitu menganalisa curah hujan harian maksimum rata-rata DAS Belawan dan menganalisa debit banjir kala ulang 2 sampai dengan 100 tahun, mensimulasi tinggi muka air banjir dengan HECRAS. Hasil studi menunjukan potensi tinggi muka air banjir DAS Belawan terjadi akibat debit banjir periode kala ulang 25 sampai dengan 100 tahun khususnya  di bagian tengah sampai hilir penampang sungai yaitu berkisar antara 0.7 m sampai dengan 3.3 m. Kata kunci: Debit banjir, Tinggi Banjir, DAS Belawan, Software HECRAS.

Analisa Kapasitas Penampang Sungai Kali Gunting Di Kabupaten Jombang

2018 ◽  
Vol 9 (2) ◽  
pp. 80-85
Author(s):  
Saiful Arfaah ◽  
Iswinarti
Keyword(s):  
Water Level ◽  
River Water ◽  
Cross Section ◽  
Return Period ◽  
Flood Mitigation ◽  
Mitigation Measures ◽  
Flood Water ◽  
Flow Parameters ◽  
Flood Discharge ◽  
Level Profile

The cause of flooding in the watershed area, one of which is caused by the inability of the river profile to accommodate the existing discharge (overflow). This research is intended to examine flood discharge and flood water level profile of Kali Gunting as a first step to determine flood mitigation solutions. Analysis of flood water level profiles using the Hec-Race 4.0 modeling program. With the help of this program, it is expected to be able to accommodate the flow parameters that are so complex. After modeling and knowing the capabilities of each part (cross section), this result will be a technical reference in determining flood mitigation measures. From the results of the study, the analysis of the potential for flooding in the scissor area was obtained as a result of the flood discharge capacity at scissors times = 301.00m3 / dt, and the emission times = 136.66m3 / dt for the 50th return period. The results of the Q50th calculation show that the condition of K. Scissors P0-P36 river water overflows / floods because the flood water level is above the eksesting embankment, while P36-P46 does not overflow / does not flood because the flood water level is below the eksesting dike. K. Panir condition P0-P48 river water overflows / floods because the flood water level is above the eksesting embankment, while P48-P60 does not overflow / does not flood because the flood water level is below the eksesting embankment

Analisa Kapasitas Penampang Sungai Kali Gunting Di Kabupaten Jombang

2018 ◽  
Vol 9 (2) ◽  
pp. 80-85
Author(s):  
Saiful Arfaah ◽  
Iswinarti Iswinarti
Keyword(s):  
Water Level ◽  
River Water ◽  
Cross Section ◽  
Return Period ◽  
Flood Mitigation ◽  
Mitigation Measures ◽  
Flood Water ◽  
Flow Parameters ◽  
Flood Discharge ◽  
Level Profile

The cause of flooding in the watershed area, one of which is caused by the inability of the river profile to accommodate the existing discharge (overflow). This research is intended to examine flood discharge and flood water level profile of Kali Gunting as a first step to determine flood mitigation solutions. Analysis of flood water level profiles using the Hec-Race 4.0 modeling program. With the help of this program, it is expected to be able to accommodate the flow parameters that are so complex. After modeling and knowing the capabilities of each part (cross-section), this result will be a technical reference in determining flood mitigation measures. From the results of the study, the analysis of the potential for flooding in the scissor area was obtained as a result of the flood discharge capacity at scissors times = 301.00m3 / dt, and the emission times = 136.66m3 / dt for the 50th return period. The results of the Q50th calculation show that the condition of K. Scissors P0-P36 river water overflows / floods because the flood water level is above the existing embankment, while P36-P46 does not overflow/does not flood because the flood water level is below the existing dike. K. Panir condition P0-P48 river water overflows / floods because the flood water level is above the existing embankment, while P48-P60 does not overflow/does not flood because the flood water level is below the existing embankment

scholarly journals The Wet and Dry Spells across India during 1951–2007

2010 ◽  
Vol 11 (1) ◽  
pp. 26-45 ◽  
Author(s):  
Nityanand Singh ◽  
Ashwini Ranade
Keyword(s):  
Climate Change ◽  
Rainfall Intensity ◽  
Total Duration ◽  
Daily Rainfall ◽  
Annual Rainfall ◽  
Change Scenario ◽  
Monsoon Period ◽  
Northwestern India ◽  
Area Of Interest ◽  
Dry Spells

Abstract Characteristics of wet spells (WSs) and intervening dry spells (DSs) are extremely useful for water-related sectors. The information takes on greater significance in the wake of global climate change and climate-change scenario projections. The features of 40 parameters of the rainfall time distribution as well as their extremes have been studied for two wet and dry spells for 19 subregions across India using gridded daily rainfall available on 1° latitude × 1° longitude spatial resolution for the period 1951–2007. In a low-frequency-mode, intra-annual rainfall variation, WS (DS) is identified as a “continuous period with daily rainfall equal to or greater than (less than) daily mean rainfall (DMR) of climatological monsoon period over the area of interest.” The DMR shows significant spatial variation from 2.6 mm day−1 over the extreme southeast peninsula (ESEP) to 20.2 mm day−1 over the southern-central west coast (SCWC). Climatologically, the number of WSs (DSs) decreases from 11 (10) over the extreme south peninsula to 4 (3) over northwestern India as a result of a decrease in tropical and oceanic influences. The total duration of WSs (DSs) decreases from 101 (173) to 45 (29) days, and the duration of individual WS (DS) from 12 (18) to 7 (11) days following similar spatial patterns. Broadly, the total rainfall of wet and dry spells, and rainfall amount and rainfall intensity of actual and extreme wet and dry spells, are high over orographic regions and low over the peninsula, Indo-Gangetic plains, and northwest dry province. The rainfall due to WSs (DSs) contributes ∼68% (∼17%) to the respective annual total. The start of the first wet spell is earlier (19 March) over ESEP and later (22 June) over northwestern India, and the end of the last wet spell occurs in reverse, that is, earlier (12 September) from northwestern India and later (16 December) from ESEP. In recent years/decades, actual and extreme WSs are slightly shorter and their rainfall intensity higher over a majority of the subregions, whereas actual and extreme DSs are slightly (not significantly) longer and their rainfall intensity weaker. There is a tendency for the first WS to start approximately six days earlier across the country and the last WS to end approximately two days earlier, giving rise to longer duration of rainfall activities by approximately four days. However, a spatially coherent, robust, long-term trend (1951–2007) is not seen in any of the 40 WS/DS parameters examined in the present study.

scholarly journals Analyses of flood peak discharge in Cimadur river basin, Banten Province, Indonesia

2021 ◽  
Vol 331 ◽  
pp. 08006
Author(s):  
Arniza Fitri ◽  
Muhammad Shubhi Nurul Hadie ◽  
Adelia Agustina ◽  
Dian Pratiwi ◽  
Susarman ◽  
...  
Keyword(s):  
River Basin ◽  
Return Period ◽  
Daily Rainfall ◽  
Annual Rainfall ◽  
Rainfall Distribution ◽  
Flood Peak ◽  
Type Iii ◽  
Pearson Type ◽  
Catchment Areas ◽  
Peak Discharges

Cimadur river basin is one of the most important catchment areas in Lebak District, Banten Province. For the past few years, the catchment has experienced floods during the rainy season. The big issue of flooding has been recorded recently in December 2019 which has caused damage and negative impacts to the local people and surrounding community. This study aims to analyze the possibility of flood peak discharges in the catchment area of the Cimadur river. The flood discharges are calculated for 2, 5, 10, 25, 50, and 100 years return period based on the daily rainfall data from the year 2011 to 2020. The rainfall and land use data are obtained from PT Saeba Consultant. In this study, the hydrological analyses are including 1) analyses of average annual rainfall using the Thiessen method; 2) analyses of rainfall distribution and estimation of design rainfall by considering three methods involving: Log-Normal, Log Pearson Type III, and Gumbel Type 1; and 3) analyses of flood discharges by adopting Nakayasu Synthetic Hydrograph Unit (SHU). The rainfall distribution analyses show that the Log Pearson Type III provided the best fit. Based on the flood peak discharges analyses, the results show that the flood discharges for the 5, 10, 25, and 50 years return period in the Cimadur river basin are 470.71 m3/s, 560.16 m3/s, 698 m3/s, and 820.4 m3/s, respectively.

scholarly journals Long term effect of climate change on rainfall in northwest Iraq

2014 ◽  
Vol 4 (3) ◽  
Author(s):  
Nadhir Al-Ansari ◽  
Mawada Abdellatif ◽  
Salahalddin Ali ◽  
Sven Knutsson
Keyword(s):  
Climate Change ◽  
Management Strategies ◽  
Daily Rainfall ◽  
Annual Rainfall ◽  
Water Shortages ◽  
Intergovernmental Panel ◽  
Continuous Decrease ◽  
Rainfall Trends ◽  
Semi Arid Region

AbstractMiddle East, like North Africa, is considered as arid to semi-arid region. Water shortages in this region, represents an extremely important factor in stability of the region and an integral element in its economic development and prosperity. Iraq was an exception due to presence of Tigris and Euphrates Rivers. After the 1970s the situation began to deteriorate due to continuous decrease in discharges of these rivers, are expected to dry by 2040 with the current climate change. In the present paper, long rainfall trends up to the year 2099 were studied in Sinjar area, northwest of Iraq, to give an idea about its future prospects. Two emission scenarios, used by the Intergovernmental Panel on Climate Change (A2 and B2), were employed to study the long term rainfall trends in northwestern Iraq. All seasons consistently project a drop in daily rainfall for all future periods with the summer season is expected to have more reduction compared to other seasons. Generally the average rainfall trend shows a continuous decrease. The overall average annual rainfall is slightly above 210 mm. In view of these results, prudent water management strategies have to be adopted to overcome or mitigate consequences of future severe water crisis.

scholarly journals Stochastic generation of annual, monthly and daily climate data: A review

2001 ◽  
Vol 5 (4) ◽  
pp. 653-670 ◽  
Author(s):  
R. Srikanthan ◽  
T. A. McMahon
Keyword(s):  
Climate Change ◽  
Historical Data ◽  
Southern Oscillation ◽  
Daily Rainfall ◽  
Annual Rainfall ◽  
Model Parameters ◽  
Annual Data ◽  
Climate Data ◽  
Time Step ◽  
Method Of Fragments

Abstract. The generation of rainfall and other climate data needs a range of models depending on the time and spatial scales involved. Most of the models used previously do not take into account year to year variations in the model parameters. Long periods of wet and dry years were observed in the past but were not taken into account. Recently, Thyer and Kuczera (1999) developed a hidden state Markov model to account for the wet and dry spells explicitly in annual rainfall. This review looks firstly at traditional time series models and then at the more complex models which take account of the pseudo-cycles in the data. Monthly rainfall data have been generated successfully by using the method of fragments. The main criticism of this approach is the repetitions of the same yearly pattern when only a limited number of years of historical data are available. This deficiency has been overcome by using synthetic fragments but this brings an additional problem of generating the right number of months with zero rainfall. Disaggregation schemes are effective in obtaining monthly data but the main problem is the large number of parameters to be estimated when dealing with many sites. Several simplifications have been proposed to overcome this problem. Models for generating daily rainfall are well developed. The transition probability matrix method preserves most of the characteristics of daily, monthly and annual characteristics and is shown to be the best performing model. The two-part model has been shown by many researchers to perform well across a range of climates at the daily level but has not been tested adequately at monthly or annual levels. A shortcoming of the existing models is the consistent underestimation of the variances of the simulated monthly and annual totals. As an alternative, conditioning model parameters on monthly amounts or perturbing the model parameters with the Southern Oscillation Index (SOI) result in better agreement between the variance of the simulated and observed annual rainfall and these approaches should be investigated further. As climate data are less variable than rainfall, but are correlated among themselves and with rainfall, multisite-type models have been used successfully to generate annual data. The monthly climate data can be obtained by disaggregating these annual data. On a daily time step at a site, climate data have been generated using a multisite type model conditional on the state of the present and previous days. The generation of daily climate data at a number of sites remains a challenging problem. If daily rainfall can be modelled successfully by a censored power of normal distribution then the model can be extended easily to generate daily climate data at several sites simultaneously. Most of the early work on the impacts of climate change used historical data adjusted for the climate change. In recent studies, stochastic daily weather generation models are used to compute climate data by adjusting the parameters appropriately for the future climates assumed.

scholarly journals Long-term trends of climate change and its impact on crop growing season on Montreal Island

2016 ◽  
Vol 8 (1) ◽  
pp. 78-88
Author(s):  
Erika Bouchard ◽  
Zhiming Qi
Keyword(s):  
Climate Change ◽  
Daily Rainfall ◽  
Growing Season ◽  
Annual Rainfall ◽  
Climate Trends ◽  
Growing Season Length ◽  
Mk Test ◽  
Long Term Trends ◽  
Increasing Trends

Long-term trends in air temperature and precipitation under climate change were analyzed for two meteorological stations on the Island of Montreal: McGill (1872–1986) and Pierre-Elliott-Trudeau (P-E-T, formerly Dorval) Airport (1942–2014). A linear trendline analysis, the Mann–Kendall (MK) test and the two-sample Kolmogorov–Smirnov (KS) test were conducted to assess specific climate trends. On a 100-year basis, temperature increased 1.88°C (34%) and 1.18°C (19%) at the McGill and P-E-T Airport sites, respectively, while annual rainfall increased 23.9 mm y−1 (2.3%) and 138.8 mm y−1 (15%) over the same period. The frequency of 50% (every other year) and 95% (every year) annual maximum daily rainfall events showed decreasing trends for the McGill station, but increasing trends for the P-E-T Airport station. Growing degree-days and growing season length are prone to being influenced by climate change and are critical to managing agricultural activities in the Montreal region; both showed increasing trends. At the same time, the onset of the growing season occurred earlier as time progressed.

scholarly journals ANALISIS CURAH HUJAN UNTUK MEMBUAT KURVA INTENSITY-DURATION-FREQUENCY (IDF) PADA SUB DAS METRO

2013 ◽  
Vol 11 (1) ◽  
Author(s):  
Ir. Ernawan S, MT ◽  
Yuda Al Qadr Latief
Keyword(s):  
Return Period ◽  
Statistical Parameter ◽  
Daily Rainfall ◽  
Rainfall Characteristics ◽  
Period 2 ◽  
Important Input ◽  
Idf Curves ◽  
Intensity Duration Frequency ◽  
Rain Events ◽  
Maximum Daily Rainfall

Ernawan S.1) , Yuda Al Qadr Latief2)1,2) Jurusan Teknik Sipil Universitas Muhammadiyah MalangAlamat korespondensi : Jl. Raya Tlogomas 246 Malang 65144AbstractHydrological conditions in Indonesia and elsewhere is typical, so not all the way and all the concepts can be used to solve the problem of hydrology in Indonesia, especially in the Upstream Brantas River precisely in Sub Watershed of Metro. Rain is an important input component in the hydrological processes. Rainfall characteristics of which are the intensity, duration, depth, and frequency. Intensity related to the duration and frequency can be expressed by curves Intensity-Duration-Frequency (IDF). IDF curves can be used to calculateflood plan to use a rational method.In this study, daily rainfall calculated by frequency analysis begins by determining the mean maximum daily rainfall, then calculate statistical parameter to choose the most suitable distribution. The time is long dominant rainfall event with the greatest frequency of rain events. The intensity is calculated by using the data of observation.Based on the analysis of the frequency of the rain turns to design return period 2, 5, 10, 20, 50 and 100 years in a row is 49; 70; 86; 111; 132 and 155 mm. The results showed that the amount of time the dominant rain events between 4-8 hours. IDF curves in sub watershed of Metro based on the data observations generally showed a pattern where the rainfall is always preceded by a high intensity then progressively decreases. Besides the greater the return period tend to have higher rainfall intensity. The results of this research could bedeveloped even if it may be modified in accordance with the specific conditions subwatershed of Metro.

Study on water infiltration characteristics in Gotjawal (forest on lava flow) wetland area

2020 ◽  
Author(s):  
Jaehoon Kim ◽  
Hyungsoon Choi ◽  
Kukman Song ◽  
Yangji Kim ◽  
Byungki Choi ◽  
...  
Keyword(s):  
Water Level ◽  
Lava Flow ◽  
Soil Layer ◽  
Daily Rainfall ◽  
Water Infiltration ◽  
Annual Rainfall ◽  
Rainfall Events ◽  
Long Time ◽  
Conservation Plan ◽  
The Republic

<p>Gotjawal is forest that was formed by the lava flow along the slopes as a result of the volcanic activity of the parasite volcanoes which distributed over Jeju Island, the Republic of Korea. Since Gotjawal has very shallow soil layer and wetland in Gotjawal does not have water for a long time, infiltration characteristics are very important. Study wetland is 48m in diameter and 2.2m in depth and water level change with respect to time was measured in 2019. The results showed that annual rainfall in this area was measured to 2,748mm and 5 rainfall events with daily rainfall more than 100mm were recorded in 2019. When the wetland was full of water, the period of drainage was 12 days. Water level started to change when the rainfall was 43~70mm taking 10~15 hours and this seems to vary depending on the period of no rainfall. This result will be helpful for estimating groundwater sources in lava flows area and for developing conservation plan of Gotjawal.</p>

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