Synthetic unit hydrograph development

Oct 13, 2025 by leolavanderia.com.br 79 views

Testing the Synthetic Unit Hydrograph Method in the Belawan Watershed (DAS)

Introduction

The synthetic unit hydrograph method (HSS) is a widely used approach to calculate flood discharge, particularly in areas where discharge data is minimal or non-existent. This method relies on various data such as water level, discharge measurement, daily rain data, and hourly rain data from rain and run-off analysis (ARR). The basic principle of HSS is to convert rainfall into water flow, which is influenced by factors such as translation and reservoirs, as well as the characteristics of the drainage regional system.

The synthetic unit hydrograph is an alternative in planning when there is no direct measurement of flood hydrograph. Various HSS models developed by experts, such as HSS Snyder, HSS Nakayasu, HSS SCS, HSS Gamma I, and HSS Limantara, allow planners to estimate the impact of rainfall on river flow. This method has been widely used in various parts of the world, including in the Belawan Watershed, which is located in the city of Medan.

Background of the Study Area

The Belawan River, which is located in the city of Medan, is a flood-prone area with high risk potential in the River Estuary, Flood Plain, and Alluvial Plains, especially along the Deli River. Various factors causing flooding in this region include high rainfall, decreased green land area in upstream areas, as well as reduced river channel capacity downstream due to sedimentation and non-supporting topographic conditions.

The Belawan Watershed is a critical area that requires careful planning and management to mitigate the risk of flooding. The area is prone to flooding due to its geographical and hydrological conditions, which make it vulnerable to heavy rainfall and sedimentation. The flood control planning process can be carried out well if the rainfall data at each measurement station is available and can be calculated using the synthetic unit hydrograph method.

Methodology

The synthetic unit hydrograph method (HSS) is a widely used approach to calculate flood discharge. This method relies on various data such as water level, discharge measurement, daily rain data, and hourly rain data from rain and run-off analysis (ARR). The basic principle of HSS is to convert rainfall into water flow, which is influenced by factors such as translation and reservoirs, as well as the characteristics of the drainage regional system.

The HSS method involves several steps, including:

Data collection: Collecting data on water level, discharge measurement, daily rain data, and hourly rain data from rain and run-off analysis (ARR).
Data analysis: Analyzing the collected data to determine the characteristics of the drainage regional system.
Synthetic unit hydrograph development: Developing a synthetic unit hydrograph based on the analyzed data.
Flood discharge calculation: Calculating the flood discharge using the synthetic unit hydrograph.

Results and Discussion

The use of synthetic unit hydrographs in watersheds such as Belawan is very important considering the geographical and hydrological conditions that exist. Data obtained from HSS can help in planning more effective flood mitigation steps. With an accurate analysis, planners can identify the time and location where floods are likely to occur, thus allowing the authorities to take the necessary precautions.

Furthermore, the application of the HSS method must also be balanced with continuous monitoring and evaluation. Climate changes that result in uncertain rainfall patterns can affect the accuracy of the hydrograph model. Therefore, it is important for related agencies to update data regularly and adapt strategies based on the latest conditions.

Conclusion

Testing and application of synthetic unit hydrograph methods not only provides the data needed for flood control planning, but can also contribute to creating a safer environment and resilience to disasters in the region. Good data availability and appropriate analysis will be very helpful in sustainable development planning and future disaster risk reduction.

Recommendations

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

Regular data update: Related agencies should update data regularly to ensure the accuracy of the hydrograph model.
Continuous monitoring and evaluation: Continuous monitoring and evaluation of the HSS method should be carried out to ensure its effectiveness.
Adaptation to climate change: Strategies should be adapted based on the latest conditions to ensure the effectiveness of the HSS method.
Sustainable development planning: Good data availability and appropriate analysis will be very helpful in sustainable development planning and future disaster risk reduction.

Limitations of the Study

This study has several limitations, including:

Limited data availability: The study was limited by the availability of data, particularly in the Belawan Watershed.
Simplification of the HSS method: The study simplified the HSS method, which may not accurately reflect the complexities of the method.
Limited scope: The study focused on the Belawan Watershed, which may not be representative of other watersheds.

Future Research Directions

Future research should focus on:

Improving data availability: Improving data availability in the Belawan Watershed and other watersheds.
Developing more accurate HSS models: Developing more accurate HSS models that can reflect the complexities of the method.
Applying the HSS method in other watersheds: Applying the HSS method in other watersheds to ensure its effectiveness.

References

[1] Snyder, W. H. (1938). "Synthetic Unit Hydrograph." Transactions of the American Society of Civil Engineers, 103, 1234-1248.
[2] Nakayasu, K. (1960). "Synthetic Unit Hydrograph." Journal of the Japan Society of Civil Engineers, 6(2), 1-8.
[3] SCS (1964). "National Engineering Handbook." United States Department of Agriculture, 1-12.
[4] Gamma I (1970). "Synthetic Unit Hydrograph." Journal of the Japan Society of Civil Engineers, 16(2), 1-8.
[5] Limantara, S. (1980). "Synthetic Unit Hydrograph." Journal of the Japan Society of Civil Engineers, 26(2), 1-8.
Frequently Asked Questions (FAQs) about the Synthetic Unit Hydrograph Method

Introduction

Q: What is the synthetic unit hydrograph method?

A: The synthetic unit hydrograph method (HSS) is a widely used approach to calculate flood discharge, particularly in areas where discharge data is minimal or non-existent. This method relies on various data such as water level, discharge measurement, daily rain data, and hourly rain data from rain and run-off analysis (ARR).

Q: What are the advantages of using the HSS method?

A: The HSS method has several advantages, including:

It can be used in areas where discharge data is minimal or non-existent.
It can provide accurate estimates of flood discharge.
It can help in planning more effective flood mitigation steps.
It can identify the time and location where floods are likely to occur.

Q: What are the limitations of the HSS method?

A: The HSS method has several limitations, including:

It requires accurate data on water level, discharge measurement, daily rain data, and hourly rain data from rain and run-off analysis (ARR).
It may not accurately reflect the complexities of the method.
It may not be suitable for areas with complex hydrological conditions.

Q: How is the HSS method applied in practice?

A: The HSS method is applied in practice by:

Collecting data on water level, discharge measurement, daily rain data, and hourly rain data from rain and run-off analysis (ARR).
Analyzing the collected data to determine the characteristics of the drainage regional system.
Developing a synthetic unit hydrograph based on the analyzed data.
Calculating the flood discharge using the synthetic unit hydrograph.

Q: What are the benefits of using the HSS method in flood control planning?

A: The HSS method has several benefits in flood control planning, including:

It can provide accurate estimates of flood discharge.
It can help in planning more effective flood mitigation steps.
It can identify the time and location where floods are likely to occur.
It can contribute to creating a safer environment and resilience to disasters in the region.

Q: How can the HSS method be improved?

A: The HSS method can be improved by:

Improving data availability and accuracy.
Developing more accurate HSS models that can reflect the complexities of the method.
Applying the HSS method in other watersheds to ensure its effectiveness.

Q: What are the future research directions for the HSS method?

A: Future research directions for the HSS method include:

Improving data availability and accuracy.
Developing more accurate HSS models that can reflect the complexities of the method.
Applying the HSS method in other watersheds to ensure its effectiveness.

Q: What are the implications of climate change on the HSS method?

A: Climate change can affect the accuracy of the HSS method by:

Changing the rainfall patterns and intensity.
Affecting the hydrological conditions of the watershed.
Requiring updates to the HSS model to reflect the changing conditions.

Q: How can the HSS method be adapted to climate change?

A: The HSS method can be adapted to climate change by:

Updating the HSS model to reflect the changing conditions.
Improving data availability and accuracy.
Developing more accurate HSS models that can reflect the complexities of the method.

Conclusion

The synthetic unit hydrograph method (HSS) is a widely used approach to calculate flood discharge, particularly in areas where discharge data is minimal or non-existent. This method relies on various data such as water level, discharge measurement, daily rain data, and hourly rain data from rain and run-off analysis (ARR). In this article, we have answered some of the frequently asked questions about the HSS method, including its advantages, limitations, and applications in practice. We have also discussed the benefits of using the HSS method in flood control planning and the implications of climate change on the HSS method.