Located in the Brahmaputra Flood Plains of Assam, the Kaziranga National Park is prone to annual floods. During monsoon season rising water level of Brahmaputra river and water flowing down from Karbi Anglong and Naga Hills through various rivers and streams inundate the low lying areas of Kaziranga. The normal inundation is important for maintenance of floral and faunal diversity in the park. Flood also recharges the water bodies and improves soil fertility. But sever flood brings destruction to the park. Flood is one of the most serious problems of Kaziranga.
Causes of Flood in Kaziranga:
1. Monsoon: Flood in Kaziranga depends on the amount of rainfall in the catchment areas of the Brahmaputra River and its tributaries. During monsoon season, Assam and entire North-East India receives great amount of rainfall. As a result, the level of water in Brahmaputra and it’s tributaries rises and enters Kaziranga. Heavy rainfall may result in successive waves high flood in same year.
2. Brahmaputra and other rivers: The great earthquake of 1950 raised the river bed of Brahmaputra. As a result, the river became shallower and wider. Moreover, gradual deposition of silt is also making the river shallower. As a result, the existing channels of the river is unable to carry the runoff during monsoon season. And the result is flooding. Several rivers originating in the Karbi Anglong and Nagaland Hills flows through Kaziranga. They also contribute to the flooding.
3. Deforestation: Due to human activities deforestation is increasing in upper catchment areas of Brahmaputra river. Deforestation results in greater runoff and promotes soil erosion. As a result, rainwater comes gushing down from the hilly areas. With the water, sediments of the eroded soil also comes down. As a result, our rivers are becoming shallower and they easily overflow during rainy season.
Kaziranga Flood Features:
The drainage system of Kaziranga consist of rivers, streams, channels, beels and vast grasslands. The floodwater enters the park gradually, but drains out rather quickly. The Northern part of Kaziranga is submerged by the Brahmaputra. This area witnesses the ravages of Brahmaputra every year. The Southern part of the park is a low lying area and is easily flooded by Mori-Diffaloo river. Water enters through Diffaloo river only after Brahmaputra starts flowing above the flood level. Sometimes Dhansiri river on the Eastern side also contributes to flooding.
With increasing water level, wildlife in the park starts moving towards higher ground. They take shelter in the high areas in the park. As there are very limited high ground inside the park, animals also migrate to the foothills of Karbi Anglong. After water lever starts to drop in Brahmaputra, flood water starts to move out from Kaziranga.
Effects of Flood on Kaziranga:
Annual flood in Kaziranga National Park of Assam has both positive and negative aspects. Some important points are discussed below.
Positive effects of Kaziranga Flood:
- Maintaining ecological balance: The annual flood influence the vegetation cover in the park. It helps in maintaining the present vegetation status and arresting process of plant succession in grasslands. Flood creates different site conditions suitable for different types of vegetation. For example: swampy and marshy areas formed due to flood and they support different types of vegetation.
- Soil formation: Floodwater also affects soil formation in different areas. In some areas alluvial deposition promotes growth of many plants. While in some areas sand deposition arrests growth of many plants.
- Replenishment: There are many water bodies such as beels inside the park. During winter months many of them dries up. Flood replenishes those beels and improves water quality of other water bodies.
- Improving soil fertility: Flood water leaves behind alluvial deposits. As a result fertility of soil increases, which is essential for growth of plants and grasses.
- Breeding of fishes: When the park is flooded, fishes from nearby water bodies come out and starts to lay eggs. With the receding floodwater, many fishes go out to from the park and replenishes the rivers.
- Removal of water hyacinth: When flood waters moves out of the park, it takes away good amount of water hyacinth from the water bodies. So, flood helps in cleaning the water bodies inside the park.
Negative effects of Kaziranga flood:
- Casualties: Rapid current of flood washes away many animals, specially small ones like deer. Also, many die due to drowning or starvation. To take shelter in higher ground, animals move towards the Karbi Anglong hills by crossing the National Highway 37. Many migrating animals are killed by poachers or fast moving vehicles.
- Shortage of fodder: During flood, grazing areas are submerged. Due to prolonged submerges, glasses start to wilt or rot. So, shortage of fodder occurs among herbivorous animals. Malnutrition is common and many animals starve to death.
- Disruption in communication: During the flood, communication between the various forest camps and Range Headquarters becomes very difficult. Patrolling is limited due to submergence of roads or tracks. Guards are forced to abandon camps in low lying areas.
- Damage to infrastructure: The annual flood damages roads, bridges, camps etc. So, it badly affects regular patrolling and ant-poaching activities in the park.