Draft:Hydrology Of Alappuzha

Hydrology of Alappuzha

Introduction

Alappuzha, also known as Alleppey, is a district in the southwestern state of Kerala, India. It is renowned for its intricate network of waterways, making it one of the most unique hydrological landscapes in the country. Alappuzha’s hydrology is dominated by its extensive system of rivers, lakes, canals, lagoons, and backwaters, which play a crucial role in its ecosystem, agriculture, and economy.

Geography and Water Bodies

Alappuzha is located along the Arabian Sea coast, with a flat terrain characterized by coastal plains and low-lying wetlands. The district covers an area of approximately 1,414 square kilometers and is bordered by the Vembanad Lake, the largest lake in Kerala, and a crucial part of its hydrological system.

1. Backwaters

The Alappuzha district is famous for its backwaters, a complex system of interconnected canals, lakes, rivers, and lagoons. These backwaters are integral to the district's identity, supporting its agriculture, fisheries, and tourism industries. The Vembanad Lake, which stretches across several districts, is the heart of this system in Alappuzha.

2. Rivers

Alappuzha is drained by several rivers that flow into the Vembanad Lake and the Arabian Sea. The most significant rivers in the district are:

• Achankovil River: Originating from the Western Ghats, this river flows through the district, merging with other water bodies and contributing to the backwater system.
• Pamba River: This is one of Kerala's longest rivers, flowing from the Western Ghats and forming an important water source for both agriculture and domestic use in Alappuzha.
• Manimala River: It is another river that flows into the Vembanad Lake and plays a role in the district's water transport and irrigation systems.

3. Canals

The canals in Alappuzha, often referred to as the "Venice of the East," are a vital part of the district's transportation and agricultural irrigation network. These canals link the lakes and rivers, forming an intricate hydrological system that sustains local livelihoods.

Hydrological Importance

The hydrology of Alappuzha is essential for the district’s socio-economic fabric, especially for its:

• Agriculture: The fertile land of Kuttanad, known as the "Rice Bowl of Kerala," is situated below sea level and depends heavily on the backwaters and canals for irrigation. The unique hydrological characteristics allow paddy cultivation even in areas with high water levels, utilizing a traditional practice known as "below sea-level farming."
• Fisheries: The inland fisheries in the backwaters of Alappuzha are a significant source of income and sustenance for local communities. Species like pearl spot, prawns, and crabs are commonly found in the region's waters.
• Tourism: The backwaters and houseboat tourism are a major attraction for visitors to Alappuzha, contributing to the local economy. The serene waterways and lush green surroundings make it a sought-after destination for eco-tourism.

Hydrological Challenges

Despite the advantages provided by its unique water systems, Alappuzha faces several hydrological challenges:

• Flooding: Due to its low-lying terrain and proximity to the sea, the district is prone to seasonal flooding, particularly during the monsoon season. The water levels in the rivers and backwaters often rise, causing inundation of the agricultural fields and residential areas.
• Water Pollution: Increasing pollution in the rivers and backwaters due to human activities, agricultural runoff, and waste disposal has become a growing concern. Water quality deterioration impacts both the aquatic life and the health of the local communities.
• Salinity Intrusion: The intrusion of saline water from the Arabian Sea into the backwaters during high tides can affect the freshwater resources and agriculture, particularly in the Kuttanad region.

Water Management

To address the challenges posed by the district’s hydrology, several water management practices have been implemented:

• Kuttanad Development Scheme: A government initiative focused on improving the drainage system, controlling floods, and enhancing agricultural productivity in the Kuttanad region.
• Thanneermukkom Bund: This saltwater barrier was constructed to prevent the intrusion of saline water into the freshwater lakes and rivers, particularly protecting the paddy fields of Kuttanad.
• River Basin Management: Efforts are being made to manage the river basins efficiently by controlling pollution, regulating sand mining, and maintaining the ecological balance of the region’s water bodies.

Climate and Rainfall

The district experiences a tropical monsoon climate with heavy rainfall during the southwest monsoon season (June to September) and the northeast monsoon (October to November). The annual average rainfall ranges between 2,500 to 3,000 mm, which significantly contributes to the water levels in the rivers, backwaters, and canals.

Conclusion

Alappuzha’s hydrology is a defining feature of the district, influencing its environment, economy, and way of life. While the district benefits from its abundant water resources, effective water management and conservation efforts are crucial to mitigate the challenges posed by flooding, pollution, and climate change. Sustainable practices will ensure the long-term viability of this unique hydrological system, preserving it for future generations.

References

• Kerala State Planning Board. Water Resources in Kerala.
• Central Water Commission. Hydrological Studies of Kerala.
• Local Government Reports on Flood and Water Management in Alappuzha.