Studying changes around Pobitora Wildlife Sanctuary: The home to One Horned Rhinos

Article by Sabnam Kalita

Land is the most important natural resource on which all activities are based. Land Use-Land Cover changes are dynamic processes taking place on the surface of the earth and it becomes a Significant component in managing natural resources and monitoring environmental changes.

The terms land use and land cover are often used interchangeably, each having its definition. The surface layer on the earth, such as vegetation, urban infrastructure, water, bare soil, and so on, is referred to as land cover. Land cover identification provides the foundation for tasks such as thematic mapping and change detection research. When used together, the terms Land Use / Land Cover (LULC) and Land Use / Land Cover (LULC) refer to the categorization or classification of human activities and natural elements on the landscape over time using proven scientific and statistical methods of analysis of suitable source materials.

Eco Sensitive Zone and its current status

The Union Ministry of Environment, Forests and Climate Change (MoEFCC) notifies areas close to National Parks and Wildlife Sanctuaries as Eco-Sensitive Zone (ESZ), aimed at creating “shock absorbers” for protected animals and birds by regulating and managing activities there. Certain industries and operations are not carried out, or subjected to safeguards, in ESZs. The Centre accepted and notified ESZs for 289 National Parks and Wildlife Sanctuaries as of November 26, 2016, and draft notifications for 206 were ready.

In 2018, the Supreme Court directed the Centre to declare “at the earliest” 10 km area around 21 National Parks and Wildlife Sanctuaries in the country as Eco-Sensitive Zone to protect wild birds and animals. A bench comprising Justices Madan B Lokur, Deepak Gupta and Hemant Gupta was informed that there are 662 National Parks and Wildlife Sanctuaries in the country. The proposals for declaring areas around these National Parks and Wildlife Sanctuaries as Eco Sensitive Zone have been received from state governments/UT Administrations for 641 National Parks and Wildlife Sanctuaries,” Additional Solicitor General A N S Nadkarni, adding that “no proposals have been received in respect of 21 National Parks and Wildlife Sanctuaries”. Thus, the governments and Union Territories administrations have not even moved any proposal to the Centre for declaring ESZ these 21 areas.

Study conducted in Pobitora Wildlife Sanctuary

A study was conducted to assess land use land cover change in the Eco sensitive zone one of the wildlife sanctuaries of Assam during 2000-2017. The study area chosen was Pobitora Wildlife Sanctuary, which is located about 30 km east of Guwahati, Morigaon district of Assam, India.

Fieldwork at Pobitora WLS

The Pobitora Wildlife Sanctuary (WLS) falls within 260 12’— 260 15 2N lat. and 91 0 57’—920 5’E long. The sanctuary area is flat with a gentle east-to-west inclination, excluding Bura Mayong hillock. It is located in the floodplains of rivers Brahmaputra, Kolong, and Pokoria. Though the total area of the sanctuary is 38.81 sq. km, the State Government is yet to hand over an area of about 11.07 sq. km to the sanctuary authority. Hence, a total of 27.74 sq. km area is under the present management of the Assam Forest Department.

The density of rhinoceros (rhino) in Pobitora is the highest; within the current distribution range of the Indian rhino. The land is mainly covered with grass and other vegetation and during the study, many changes were not seen inside the sanctuary as it has been protected because rhinos need grassland for grazing. However, outside the sanctuary within 2km buffer area there was an increase of settlement mainly from the year 2010 as seen in the study and an increase in brick industries near and around the eco sensitive zone. The study area also has villages in the zone; these villages are present in the area since a very long time now and as said by the villagers they have never faced any rhino conflict.

Land use/Land cover changes were assessed and compared over a period of 17 years (2000-2017) by using Remote Sensing (RS) and Geographic Information Systems (GIS) technique. The data used for the study were Survey of India toposheets and satellite imageries for the years 2000, 2010 and 2010.

Of the total 140 sq. km area of the Eco Sensitive Zone, it was found that maximum changes were seen in Moist Mixed Deciduous, Degraded forest and Built up Area. Variation in the area existed for Sandy areas, decrease in the area observed in Moist Mixed Deciduous Forest, increase observed in Degraded Forest and an increase was also observed in the Built up area.

Moist Mixed Deciduous Forest has reduced from 11.08%in 2000 to 7.09% in 2017

Degraded Forest has increased from 3.41% in 2000 to 6.46% in 2017


Built up has increased from 2.66% in 2000 to 5.19% in 2017.

LULC Map 2000
LULC Map 2017

The above were the major changes observed in the last 17 years using Remote Sensing and GIS techniques whereas in other land use & land cover classes only a few decimal changes were observed. During the period 2010 to 2017, degraded forest have increased due to deforestation and smuggling of wooden logs. The study also aimed to identify industrial areas near the sanctuary. Not many industries including brick industries were observed near the sanctuary. Whatever industries were found existed few kilometers away from the protected area. According to the forest department as well, no industry is situated that nearby to the sanctuary, they are all present at a distance away. An increase in built up was observed due to increasing brick industries in the surrounding and the employees of the industries settling in the area, which have drastically impacted the sanctuary. Previously there were electric wire fencing around the zone which was eventually removed as the villagers protested against it, human interferences and poaching has also thus increased. 

Thus, Forest and land cover change detection is one of the major applications of satellite-based remote sensing. The study showed that remotely sensed data provide striking spatial detail about the earth’s surface, which serves as a better data source for environmental change studies.

After various studies and research on wildlife sanctuaries and national parks using GIS techniques, it has been observed that the eco sensitive zones can be drastically affected by human interferences. Poaching, encroachment and rise in urban growth disturb wildlife habitat and bring nature into a great devasted situation. Encroaching wildlife habitats brings animals to busy city roads and within human localities, which eventually creates human-wildlife conflicts. However, simply delimitating the ESZ does not solve the local socio-ecological problems. There is a need to reconsider the local effects of environmental policies, the types, and prospects of local engagement, and, most critically, the prospects for alternative revenue generation for effective conservation initiatives.

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