scholarly journals Method for Operating Drainage Pump Stations Considering Downstream Water Level and Reduction in Urban River Flooding

Water ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 2741
Author(s):  
Yeon-Moon Choo ◽  
Jong-Gu Kim ◽  
Shang-Ho Park ◽  
Tai-Ho Choo ◽  
Yeon-Woong Choe

Korea experiences increasing annual torrential rains owing to climate change and river flooding. The government is expanding a new drainage pump station to minimize flood damage, but the river level has not been adjusted because of torrential rains. Therefore, the river level must be adjusted to operate the drainage pump station, and it can be adjusted through the reservoir of the drainage pump station. In this study, we developed a method for operating drainage pump stations to control the river level and verify the effectiveness of the proposed method. A stormwater management model (SWMM) was used to simulate the Suyeong River and Oncheon River in Busan, Korea. The rainfall data from 2011 to 2021 were investigated. The data were sorted into ten big floods that occurred in Busan. The model was calibrated with actual rainfall data. The water level of the Suyeong River and the Oncheon River was the highest in most simulations. The simulation results showed an average decrease of 3018.2 m3 in Suyeong River flooding, and the Oncheon River needed to be supplemented due to structural problems. As a result of the recombination by simply supplementing the structural problems of the Oncheon River, the average flooding of 194.5 m3 was reduced. The proposed method is economical and efficient for reducing urban stream flooding in areas susceptible to severe damage caused by climate change.

2021 ◽  
Vol 5 (1) ◽  
pp. 126-134
Author(s):  
A. B. Adegbehin ◽  
E. O. Iguisi ◽  
Y. O. Yusuf ◽  
C. K. Dauda

The focus of this empirical study is to investigate the trends of some hydro metrological parameters and Impact Vulnerability Status (IVS) of irrigation water resources on rice and tomato production in the downstream of Tiga station. Investigation was conducted using data on rainfall, temperature, evaporation and reservoir water level for 30 years in Tiga station. The data collected was used to show the trend fluctuations of each parameter for the period of study. The rainfall data was also used to analyze the Normalized Rainfall Index (NRI) in order to know periods of surplus, deficit and optimal water availability as against the required water for rice and tomato production. The rainfall pattern and water level showed increasing trend while temperature and evaporation showed a general decrease in trend. The NRI used to investigate the IVS in Tiga station downstream revealed that rice and tomato were not vulnerable to drought and flooding for 18 years while every other years were vulnerable or slightly vulnerable. However, only year 1993 appears to be very wet and highly susceptible to flooding. Findings from focus group revealed that 80% of the farmers reported floods occurrences during rainy season and deficit of water between January and March of each year. In conclusion, the IVS of farmers to climate change revealed periods of deficit, optimal and excess water availability for rice and tomato production and their vulnerability status. It was recommended that the government should strengthen laws and policies relevant in addressing climate change


Water ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 99
Author(s):  
Won Jin Lee ◽  
Eui Hoon Lee

Runoff in urban streams is the most important factor influencing urban inundation. It also affects inundation in other areas as various urban streams and rivers are connected. Current runoff predictions obtained using a multi-layer perceptron (MLP) exhibit limited accuracy. In this study, the runoff of urban streams was predicted by applying an MLP using a harmony search (MLPHS) to overcome the shortcomings of MLPs using existing optimizers and compared with the observed runoff and the runoff predicted by an MLP using a real-coded genetic algorithm (RCGA). Furthermore, the results of the MLPHS were compared with the results of the MLP with existing optimizers such as the stochastic gradient descent, adaptive gradient, and root mean squared propagation. The runoff of urban steams was predicted based on the discharge of each pump station and rainfall information. The results obtained with the MLPHS exhibited the smallest error of 39.804 m3/s when compared to the peak value of the observed runoff. The MLPHS gave more accurate runoff prediction results than the MLP using the RCGA and that using existing optimizers. The accurate prediction of the runoff in an urban stream using an MLPHS based on the discharge of each pump station is possible.


Water ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 756
Author(s):  
Dong-Ho Kang ◽  
Dong-Ho Nam ◽  
Se-Jin Jeung ◽  
Byung-Sik Kim

Korea has frequent flood damage due to localized torrential rain and typhoons as a result of climate change, which causes many casualties and property damage. In particular, much damage occurs due to urban inundation caused by stream flooding as a result of climate change. Thus, this study aims to analyze the effect of climate change on flood damage targeting the Wonjucheon basin, which is an urban stream flowing the city. For future rainfall data, RCP (Representative Concentration Pathways) 8.5 climate change scenario data was used, statistical detailed using SDQDM (Spatial Disaggregation with Quantile Delta Mapping) techniques, and daily data was downscaled using Copula model. In general, the flood damage rate is calculated by using the area ratio according to the land use in the administrative district, but in this study, the flood damage rate is calculated using the flood damage rate proposed in the multi-dimensional flood damage analysis using Building Inventory. Using the created future rainfall data and current data, the runoff in the Wonjucheon basin, Wonju-si, South Korea, by rainfall frequency was calculated through the Spatial Runoff Assessment Tool (S-RAT) model, which was a distributed rainfall-runoff model. The runoff was calculated using 100-year and 200-year frequency rainfalls for a four-hour duration and the flood damage area was calculated by applying the calculated runoff to the Flo-2D model, was developed by Federal Emergency Management Agency (FEMA) in United State of America, which was a flood inundation model. As a result of calculating the amount of discharge, it was analyzed that the average amount of discharge increased by 16% over the 100-year, 200-year frequency. The calculated result of the flood damage area was analyzed and the analysis results showed that the future flood damage area increased by around 30% at the 100-year frequency and around 15% at the 200-year frequency. The estimated flood damage by rainfall frequency was calculated using the flood damage area by frequency and multi-dimensional analysis, and the analysis result exhibited that the damage increased by around 23% at the 100-year frequency and around 45% at the 200-year frequency.


CERUCUK ◽  
2021 ◽  
Vol 5 (1) ◽  
pp. 17
Author(s):  
Ahdianoor Fahraini ◽  
Achmad Rusdiansyah

According to the World Meteorological Organization that 2014 was the hottest year in which the hot weather alternated with high rainfall and floods which destroyed the people's economy. Banjarbaru, as one of the central cities of the government of South Kalimantan Province, has a topographic condition that is at an altitude of 0-500 m above sea level, causing rainfall, which is enough frequent. Banjarbaru itself is one of the cities affected by climate change in 2014. Disasters that occurred in the form of flooding at several points of residents and also crippled traffic at that time. Thus, it is important to know the pattern of maximum rainfall changes that occur. By knowing the pattern of maximum rainfall changes, the impact of the high rainfall that can occur will be minimized and can even be anticipated as early as possible.            Data processing is performed with maximum daily rainfall data of 30 years and divided into a database before and after climate change that is 25 years old data and 5 years of new data. Each database calculates the planned rainfall for the return period of 2-1000 years with the distribution obtained from the analyzed database. Next, analyze the deviation of the two data. The purpose of analyzing the deviation of old data and new data is to determine changes in the planned rainfall from both data. Deviation analysis uses the Peak-Weight Root Mean Square Error function.            The conclusion of the analysis is that based on the Statistical Parameters test, the Chi-Square test, and the Smirnov-Kolmogorov test on the old database using the Gumbel distribution and the new data using the Pearson Log Type III distribution for the calculation of the planned rain. Based on the analysis of the rain plan to get new data 5 years has the results of the rain plan is greater than the old data of 25 years and the analysis of the deviation to get the results of the new data 5 years has a greater value of deviation each time when revisiting the old data of 25 years. So it can be suggested that rainfall data with the same characteristics, can use 5 years of new data for the analysis of water building planning.


Politeia ◽  
2018 ◽  
Vol 37 (1) ◽  
Author(s):  
Mbekezeli Comfort Mkhize ◽  
Kongko Louis Makau

This article argues that the 2015 xenophobic violence was allowed to spread due to persistent inaction by state officials. While the utterances of King Goodwill Zwelithini have in part fuelled the attacks, officials tend to perceive acts of xenophobia as ordinary crimes. This perception has resulted in ill-advised responses from the authorities, allowing this kind of hate crime against foreign nationals to engulf the whole country. In comparison with similar attacks in 2008, the violent spree in 2015 is characterised by a stronger surge in criminal activities. The militancy showcased fed a sense of insecurity amongst foreigners, creating a situation inconsistent with the country’s vaunted respect for human rights and the rule of law. Investors lost confidence in the country’s outlook, owing in part to determined denialism in government circles regarding the targeting of foreigners. While drawing from existing debates, the article’s principal objective is to critically examine the structural problems that enable xenophobia to proliferate and the (in)effectiveness of responses to the militancy involved in the 2015 attacks. Of particular interest are the suggested responses that could be effective in curbing future violence. The article concludes that xenophobia is systemic in post-apartheid South Africa. Strong cooperation between the government, national and international organisations could provide the basis for successful anti-xenophobia measures. The article further argues that the country is obliged to find a sustainable solution to the predicament for humanitarian reasons firstly, and in recognition of the support South Africans received from its African counterparts during the liberation struggle.


2020 ◽  
Vol 4 (1) ◽  
pp. 129-139
Author(s):  
Naresh Bhakta Adhikari

The paper mainly analyses the environmental threats focusing on climate change to human security in Nepal. Major aspects of human security are interlinked and interconnected in our context. Among them, human security offers much to the vibrant field of environmental security in Nepal. Environmental threats are linked to the overall impact on human survival, well-being, and productivity. A great deal of human security is tied to peoples’ access to natural resources and vulnerabilities to environmental change. The major environmental threats in our context is the climate change which have widespread implications for Nepal, causing impacts to water availability, agricultural production, forestry, among many other detrimental effects. The critical threat of environmental security needs to be taken into serious consideration to save our succeeding generation. This article primarily interpreted the government action towards emerging environmental threat based on realist approach. For the study of theme of this article, descriptive and analytical research has been used to draw present major environmental threats in Nepal. With consideration to factors, this article attempted to identify the major environmentally vulnerable areas that are likely to hamper the overall status of human security in Nepal. This paper also tried to suggest the measures to enhance the environmental security considering prospects and policy focusing on Nepalese diverse aspects.


2009 ◽  
Vol 160 (7) ◽  
pp. 195-200
Author(s):  
Reto Hefti

In the mountainous canton Grisons, much visited by tourists, the forest has always had an important role to play. New challenges are now presenting themselves. The article goes more closely into two themes on the Grisons forestry agenda dominating in the next few years: the increased use of timber and climate change. With the increased demand for logs and the new sawmill in Domat/Ems new opportunities are offered to the canton for more intensive use of the raw material, wood. This depends on a reduction in production costs and a positive attitude of the population towards the greater use of wood. A series of measures from the Grisons Forestry Department should be of help here. The risk of damage to infrastructure is particularly high in a mountainous canton. The cantonal government of the Grisons has commissioned the Forestry Department to define the situation concerning the possible consequences of global warming on natural hazards and to propose measures which may be taken. The setting up of extensive measurement and information systems, the elaboration of intervention maps, the estimation of the danger potential in exposed areas outside the building zone and the maintenance of existing protective constructions through the creation of a protective constructions register, all form part of the government programme for 2009 to 2012. In the Grisons, forest owners and visitors will have to become accustomed to the fact that their forests must again produce more wood and that, on account of global warming, protective forests will become even more important than they already are today.


2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Hendri Irwandi ◽  
Mohammad Syamsu Rosid ◽  
Terry Mart

AbstractThis research quantitatively and qualitatively analyzes the factors responsible for the water level variations in Lake Toba, North Sumatra Province, Indonesia. According to several studies carried out from 1993 to 2020, changes in the water level were associated with climate variability, climate change, and human activities. Furthermore, these studies stated that reduced rainfall during the rainy season due to the El Niño Southern Oscillation (ENSO) and the continuous increase in the maximum and average temperatures were some of the effects of climate change in the Lake Toba catchment area. Additionally, human interventions such as industrial activities, population growth, and damage to the surrounding environment of the Lake Toba watershed had significant impacts in terms of decreasing the water level. However, these studies were unable to determine the factor that had the most significant effect, although studies on other lakes worldwide have shown these factors are the main causes of fluctuations or decreases in water levels. A simulation study of Lake Toba's water balance showed the possibility of having a water surplus until the mid-twenty-first century. The input discharge was predicted to be greater than the output; therefore, Lake Toba could be optimized without affecting the future water level. However, the climate projections depicted a different situation, with scenarios predicting the possibility of extreme climate anomalies, demonstrating drier climatic conditions in the future. This review concludes that it is necessary to conduct an in-depth, comprehensive, and systematic study to identify the most dominant factor among the three that is causing the decrease in the Lake Toba water level and to describe the future projected water level.


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