Analysis Of The Babura River Flood Puddle Area Based Hec - Ras And GIS

by ADMIN 71 views

Introduction

Floods are one of the most devastating natural disasters that often hit Indonesia, particularly in the city of Medan. The city's geography, with its numerous rivers and low-lying areas, makes it prone to flooding. In order to mitigate flood disasters, it is essential to have a map that shows vulnerable areas to standing water. This study aims to produce a map of the Babura River flood inundation that flows through the Medan City area due to the overflow of the river. To achieve this goal, a cross-section measurement data is used, the topography obtained through Light Detection and Ranging (LIDAR) technology, as well as the digital elevation model from Demnas. The process of modeling this flood inundation map involves the integration of the Hydrological Engineering Center-River Analysis System (HEC-RAS) software with QGIS.

The importance of having a flood inundation map cannot be overstated. It provides policy makers with valuable information to manage flood risk, enabling them to take proactive steps to mitigate the impact of flooding. By knowing the risk area, mitigation steps can be taken, such as better spatial planning, adequate drainage infrastructure development, and counseling to the public about the actions that must be taken when the disaster has hit.

Methodology

In this study, the Log Person III method was used to meet the distribution requirements of the rainfall frequency, which was tested through the Chi-squadrate test and the Smirnov-Oholmogorof test. In addition, to calculate water discharge in various repeat periods, the Nakayasu synthetic unit hydrograph method is applied, which includes period 1, 2, 5, 10, 20, 25, 50, and 100 years. The results of the analysis showed that there were 19 villages that had the potential to be flooded, namely Anggrung, Banyan, Land, Johor Building, Teak, Kesawan, Kwala Bekala, Mango, Merdeka, Padang Bulan, Pangkalan Mansyur, Pasar Red Barat, Petisah Hulu, Petisah Tengah, Polonia, Sarirejo, Sikambing D, Simalingkar B, and Titi Chain.

Further analysis using Lidar's topographic data shows the RMSE (Root Mean Square Error) value that reflects the accuracy of the model. The RMSE value for the field path compared to Lidar's topographic data is 2.73; for DEMNAS topographic data of 4.74; And between Lidar's path data and Demnas is 3.40. Meanwhile, the RMSE value for the inundation area obtained from Lidar's topographic data on Demnas varies, which is 0.1052; 0.1176; 0.1208; 0.1250; 0.1252; 0.1253; and 0.1210 for back discharge 1, 2, 5, 10, 20, 25, 50, and 100 years.

The Importance of a Flood Inundation Map

A flood inundation map is a crucial tool for policy makers in managing flood risk. By knowing the risk area, mitigation steps can be taken, such as better spatial planning, adequate drainage infrastructure development, and counseling to the public about the actions that must be taken when the disaster has hit. The integration of GIS and Hec-Ras technology provides advantages in making an accurate and reliable inundation map. This not only provides a visual picture of the risk of flooding, but also allows a deeper analysis of the relationship between rainfall and the impact of flooding in the area.

Conclusion

In conclusion, the analysis of the inundation area of ​​the Babura River Based on Hec-Ras and GIS is not only an academic effort, but also as a significant contribution in disaster mitigation efforts in Medan. The results of this study provide valuable information to policy makers, enabling them to take proactive steps to mitigate the impact of flooding. By understanding the potential threat of flooding, the people of Medan can take proactive steps in dealing with these conditions. Therefore, the adoption of the results of this flood inundation map will provide added value for the people of Medan to understand the potential threat of flooding.

Recommendations

Based on the results of this study, the following recommendations are made:

  1. Environmental Management: The results of this study should be followed up with programs that focus on environmental management and disaster risk reduction. This includes the development of adequate drainage infrastructure, better spatial planning, and counseling to the public about the actions that must be taken when the disaster has hit.
  2. Disaster Risk Reduction: The adoption of the results of this flood inundation map will provide added value for the people of Medan to understand the potential threat of flooding. This will enable them to take proactive steps in dealing with these conditions.
  3. Further Research: Further research is needed to improve the accuracy of the flood inundation map. This includes the use of more advanced technologies, such as satellite imaging and LiDAR, to improve the accuracy of the map.

Limitations

This study has several limitations, including:

  1. Data Quality: The quality of the data used in this study is a limitation. The data used was obtained from various sources, including DEMNAS and Lidar's topographic data. However, the accuracy of the data may be affected by various factors, such as the quality of the data collection process and the accuracy of the data processing.
  2. Modeling Limitations: The HEC-RAS model used in this study has limitations. The model is based on a simplified representation of the flood inundation process, which may not accurately represent the complex processes involved in flooding.
  3. Scalability: The results of this study are limited to the Babura River flood inundation area. The study did not consider the impact of flooding on other areas, such as the surrounding villages and cities.

Future Research Directions

Future research directions include:

  1. Improving the Accuracy of the Flood Inundation Map: Further research is needed to improve the accuracy of the flood inundation map. This includes the use of more advanced technologies, such as satellite imaging and LiDAR, to improve the accuracy of the map.
  2. Considering the Impact of Flooding on Other Areas: The study did not consider the impact of flooding on other areas, such as the surrounding villages and cities. Future research should consider the impact of flooding on these areas.
  3. Developing a More Comprehensive Flood Risk Management Plan: The study provides valuable information to policy makers, enabling them to take proactive steps to mitigate the impact of flooding. However, a more comprehensive flood risk management plan is needed to address the complex issues involved in flooding.

Q: What is the purpose of the study?

A: The purpose of the study is to produce a map of the Babura River flood inundation that flows through the Medan City area due to the overflow of the river. The study aims to provide a valuable tool for policy makers to manage flood risk and take proactive steps to mitigate the impact of flooding.

Q: What methods were used in the study?

A: The study used the Log Person III method to meet the distribution requirements of the rainfall frequency, which was tested through the Chi-squadrate test and the Smirnov-Oholmogorof test. Additionally, the Nakayasu synthetic unit hydrograph method was applied to calculate water discharge in various repeat periods.

Q: What are the limitations of the study?

A: The study has several limitations, including data quality, modeling limitations, and scalability. The accuracy of the data used in the study may be affected by various factors, such as the quality of the data collection process and the accuracy of the data processing. Additionally, the HEC-RAS model used in the study has limitations, and the results of the study are limited to the Babura River flood inundation area.

Q: What are the recommendations of the study?

A: The study recommends the following:

  1. Environmental Management: The results of the study should be followed up with programs that focus on environmental management and disaster risk reduction.
  2. Disaster Risk Reduction: The adoption of the results of the flood inundation map will provide added value for the people of Medan to understand the potential threat of flooding.
  3. Further Research: Further research is needed to improve the accuracy of the flood inundation map and to consider the impact of flooding on other areas.

Q: What are the future research directions?

A: The future research directions include:

  1. Improving the Accuracy of the Flood Inundation Map: Further research is needed to improve the accuracy of the flood inundation map using more advanced technologies, such as satellite imaging and LiDAR.
  2. Considering the Impact of Flooding on Other Areas: The study did not consider the impact of flooding on other areas, such as the surrounding villages and cities. Future research should consider the impact of flooding on these areas.
  3. Developing a More Comprehensive Flood Risk Management Plan: A more comprehensive flood risk management plan is needed to address the complex issues involved in flooding.

Q: What are the benefits of the study?

A: The study provides valuable information to policy makers, enabling them to take proactive steps to mitigate the impact of flooding. The adoption of the results of the flood inundation map will provide added value for the people of Medan to understand the potential threat of flooding.

Q: What are the implications of the study?

A: The study has significant implications for disaster risk reduction and management in Medan. The results of the study provide a valuable tool for policy makers to manage flood risk and take proactive steps to mitigate the impact of flooding.

Q: What are the next steps?

A: The next steps include:

  1. Implementing the Recommendations: The recommendations of the study should be implemented, including environmental management and disaster risk reduction programs.
  2. Further Research: Further research is needed to improve the accuracy of the flood inundation map and to consider the impact of flooding on other areas.
  3. Developing a More Comprehensive Flood Risk Management Plan: A more comprehensive flood risk management plan is needed to address the complex issues involved in flooding.