Evaluation Of The Cross-section Capacity Of The Binjai City River On Flood Discharge Using The Hec-Ras Method

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Introduction

Flooding is a natural disaster that often occurs, especially in the rainy season, causing significant impacts on people living along riverbanks. One of the main causes of flooding is the existence of careless waste disposal, resulting in narrowing of the river flow. This article aims to evaluate the cross-section of the Binjai City River and find the right solution in controlling floods through comprehensive analysis.

Background and Significance

Flooding is a major concern for communities living along rivers, causing damage to properties, loss of life, and disruption of daily activities. The impact of flooding is exacerbated by the increasing frequency and severity of extreme weather events. In recent years, Binjai City has experienced several flooding incidents, highlighting the need for effective flood management strategies. This study aims to contribute to the development of a comprehensive flood management plan for Binjai City by evaluating the cross-section capacity of the Binjai City River using the Hec-Ras method.

Methodology

This study employed a combination of analytical and numerical methods to evaluate the cross-section capacity of the Binjai City River. The analysis includes:

  1. Analysis of Maximum Average Rainfall: Using data from three rainfall observation stations, this information is crucial in determining the potential flow of water during heavy rain.
  2. Flood Discharge Analysis: To find out how much water discharge can flow into the Binjai City River, this research uses the HSS Nakayasu method.
  3. Flood Hydrograph Unit: Produces a hydrograph curve that can help in understanding the distribution of flood discharges in a certain time.

The analysis process begins by applying the Thiessen polygon method to accurate rainfall data. Furthermore, a probability distribution test is carried out to get a more accurate estimate of flood discharge.

Analysis Results

From the analysis conducted, the results obtained that the peak of the flood discharge reached 8,285 m³/sec with peak time of 1.62 hours. In addition, the results of the analysis for the flood debit plan by the HSS Nakayasu method showed sequential values for intervals of 2 years, 5 years, 10 years, 25 years, 25 years, and 100 years each M³/sec, 525,118 m³/sec, 535,372 m³/sec, 540,268 m³/sec, and 543,670 m³/sec.

The cross-section of the Binjai City River itself, based on calculations, is 17.023 m³/sec with a flow velocity of 0.806 m/sec.

Capacity and Recommendations Analysis

Based on the analysis using Hec-Ras 6.0, it appears that the current capacity does not meet the flood discharge plan on various birthdays. This shows that the Binjai City River does not have enough capacity to accommodate flood discharge that occurs, so that it has a great potential to experience more severe floods in the future.

To overcome this problem, several steps need to be taken:

  1. River Cleaning: Eliminating garbage and other blockages that can narrow the river flow.
  2. Good Water Resource Management: Apply a better strategy for rainfall management and water flow.
  3. Infrastructure Development: Consider building reservoirs or additional sewers to collect water during the rainy season.

Conclusion

This study highlights the importance of better understanding of local environmental conditions to reduce the risk of flooding that threatens the lives of people along the Binjai City River. The results of this study demonstrate the need for effective flood management strategies, including river cleaning, good water resource management, and infrastructure development. By working together, the government and the community can maintain river cleanliness and develop a sustainable flood management plan to prevent future disasters.

Recommendations for Future Research

This study provides a comprehensive analysis of the cross-section capacity of the Binjai City River using the Hec-Ras method. However, there are several areas that require further research, including:

  1. Development of a comprehensive flood management plan: This plan should include strategies for river cleaning, good water resource management, and infrastructure development.
  2. Implementation of flood early warning systems: This system should provide timely warnings to communities living along the river to enable them to take necessary precautions.
  3. Conducting regular flood risk assessments: This assessment should be conducted to identify areas that are prone to flooding and to develop strategies for mitigating the impact of flooding.

By addressing these areas, this study can contribute to the development of effective flood management strategies that can reduce the risk of flooding and protect the lives of people living along the Binjai City River.

Q1: What is the Hec-Ras method, and how is it used in this study?

A1: The Hec-Ras method is a computer program developed by the US Army Corps of Engineers to simulate the behavior of rivers and streams. In this study, the Hec-Ras method is used to evaluate the cross-section capacity of the Binjai City River and to simulate the flood discharge that occurs during heavy rainfall events.

Q2: What are the main causes of flooding in Binjai City, and how can they be addressed?

A2: The main causes of flooding in Binjai City include careless waste disposal, which results in narrowing of the river flow, and inadequate water resource management. To address these issues, river cleaning, good water resource management, and infrastructure development are necessary.

Q3: What is the current capacity of the Binjai City River, and does it meet the flood discharge plan on various birthdays?

A3: The current capacity of the Binjai City River is 17.023 m³/sec with a flow velocity of 0.806 m/sec. However, the analysis using Hec-Ras 6.0 shows that the current capacity does not meet the flood discharge plan on various birthdays, indicating that the river does not have enough capacity to accommodate flood discharge that occurs.

Q4: What are the recommendations for overcoming the problem of insufficient capacity of the Binjai City River?

A4: The recommendations for overcoming the problem of insufficient capacity of the Binjai City River include:

  1. River cleaning: Eliminating garbage and other blockages that can narrow the river flow.
  2. Good water resource management: Apply a better strategy for rainfall management and water flow.
  3. Infrastructure development: Consider building reservoirs or additional sewers to collect water during the rainy season.

Q5: What is the importance of better understanding of local environmental conditions to reduce the risk of flooding?

A5: Better understanding of local environmental conditions is crucial in reducing the risk of flooding. This includes understanding the behavior of rivers and streams, the impact of human activities on the environment, and the potential risks associated with flooding.

Q6: What are the implications of this study for flood management in Binjai City?

A6: This study highlights the need for effective flood management strategies in Binjai City, including river cleaning, good water resource management, and infrastructure development. By working together, the government and the community can maintain river cleanliness and develop a sustainable flood management plan to prevent future disasters.

Q7: What are the limitations of this study, and what are the areas for future research?

A7: The limitations of this study include the use of a single method (Hec-Ras) to evaluate the cross-section capacity of the Binjai City River and the lack of consideration of other factors that may influence flood discharge. Future research should focus on developing a comprehensive flood management plan, implementing flood early warning systems, and conducting regular flood risk assessments.

Q8: What are the potential benefits of implementing the recommendations of this study?

A8: The potential benefits of implementing the recommendations of this study include:

  1. Reduced risk of flooding: By maintaining river cleanliness and developing a sustainable flood management plan, the risk of flooding can be reduced.
  2. Protection of lives and properties: Effective flood management strategies can protect lives and properties from the impact of flooding.
  3. Improved water quality: Good water resource management can improve water quality and reduce the risk of water-borne diseases.

Q9: What are the next steps in implementing the recommendations of this study?

A9: The next steps in implementing the recommendations of this study include:

  1. Developing a comprehensive flood management plan: This plan should include strategies for river cleaning, good water resource management, and infrastructure development.
  2. Implementing flood early warning systems: This system should provide timely warnings to communities living along the river to enable them to take necessary precautions.
  3. Conducting regular flood risk assessments: This assessment should be conducted to identify areas that are prone to flooding and to develop strategies for mitigating the impact of flooding.