Читать книгу Pollutants and Water Management - Группа авторов - Страница 52

Many of the wetlands in India support the livelihood of thousands of people every day, however, an increasing population and their encroachment into the wetlands either directly or indirectly pose a threat of degradation. In addition, the variations in climatic conditions, especially rainfall and temperature, which are crucial for maintaining water levels, is another important reason in the degradation of wetlands (Sarthi and Singh 2013). The average monthly precipitation over this area was in the range of 92.61–128.44 mm during 2012–2016, which is less than the expected precipitation (140 mm), and clearly indicates a water shortage. This site is a declared wildlife sanctuary and bird sanctuary with an area of 6311 ha by MoEF, the Government of India, and the Government of Bihar, however, there is still no clear‐cut outer boundary demarcation, and only the core waterlogging area of 2350 ha is monitored by the agencies. This wetland is used for the water supply of irrigation and domestic purposes, fishing, netting of waterfowls, the harvesting of wild fruits like singhara (Trapa natans) and makhana (Euryale ferox), edible mollusks (Pila globosa) (Ambastha et al. 2007a, b; Kumar 2013a), and the cultivation of wild rice on open lands (Scott 1989). When this wetland was declared a protected area in 1986, all the landholders who lost their land were promised compensation under the provisions of the Land Acquisition Act (1894) by the government, however, many people are still claiming land ownership rights in the wetland area. There have been more than 15 legal petitions and approximately 1600 public objections are still pending before the local administration and court regarding these issues as per different reports. The rights for the access of different wetland resources were given to some of the local communities for fishing, vegetation biomass collection, and wild paddy cultivation in the wetland under the provisions of the Indian Wildlife (Protection) Act 1972, while land deals, bird trapping, and wild animal poaching were banned (Rakshi and Sanghi 1996; Kumar 2013b).

As per the report of the Centre for Monitoring Indian Economy (CMIE 2008), the villages surrounding the Kanwar wetland are highly populated and underdeveloped. The wetland has lost its connectivity to the main river and is now considered an oxbow and a rain‐fed wetland in some of the literature (Kumar 2013a). The reduced rainfall over this region is the reason for water scarcity and the heavy siltation is the reason for the decrease in the water logging area. The relatively elevated areas of the wetland, locally called Rahis, and the low‐lying areas, called Dove, were intensively encroached by people, which have altered the land‐use dynamics of this wetland. The water and sediment quality is mainly becoming compromised with harmful heavy metals from different sources (Figure 2.12), which are posing a severe threat not only for the resources of the wetland but also to the health of the dependent population. The heavy siltation in different stretches, the premature death of fish, the intensive growth of weed biomass like Eichhornia, and the reporting of frequent human diseases of skin allergies, indigestion, blood pressure, and kidney and nervous disorders are very common among the population (Singh et al. 2018).

Figure 2.12 Elevation map of the Kanwar watershed showing possible sources of heavy metals.

(Source: Based on Struhsaker et al. 2005.)

Even though most of the population around the wetland was highly dependent on its resources, they were still very positive and ready to cooperate with the administration in the co‐management and conservation of the wetland. Therefore, a collaborative approach needs to be initiated to address the issues of this wetland and dependent population for its effective management and conservation as suggested by Struhsaker et al. (2005).