Remote Sensing and GIS for assessment of change and in India

Shweta Sharma

6th December 2012

India supports a population of more than one billion people. India is also the world’s 9th largest economy. It has the second largest farm output in the world. Hence it is very essential to conserve and manage the health of its natural resources like forests, land, water etc. India, being one of the leading developers of remote sensing in the world has the capability of monitoring and managing its land use and land cover areas pertinently.(Wikiperdia)

A massive farm output, a rapidly developing economy and a huge population are a few major factors that indicate the strain on India’s natural resources, precisely forests. In 2010, India’s was 68 million hectares or about 20% of the country’s area as estimated by the Food Agriculture organization of the United Nations (Wikipedia). There has been reduction in dense forest in all major states of India.

Large areas of land are acquired for agricultural practices, which results in deforestation. Deforestation is reduction of forest cover i.e. from dense forests to fragmentation of forests, open forests, scrubs or degradation of land use. Deforestation is caused by , agriculture, degradation of forests, , shifting agriculture, expansion of cities etc. Deforestation can cause many problems like of endemic species (plant and animal),loss of , flooding, soil , increase in green house gases, and global warming to name a few.(C. Sudhakar Reddy et al 2009). National economies are dependent on the consumption of their natural renewable and nonrenewable resources. Deforestation has become a global concern. In 50 years 9 million square kms of humid forest has been degraded or cleared.

India is one of the 25 biodiversity hotspots of the world because of its pockets of rich forests supporting varied life forms.(Wikipedia) It is quite essential to timely examine the effects of environmental changes like climate change, land use change, encroachment in protected areas etc. The most cost effective and accurate way of keeping a check on land use change is by remote sensing and GIS technology.

Remote sensing and GIS are used in –

 Analyses of land cover and land use changes  Estimation of deforestation rates and forest fragmentation rates  Examination of the spatial correlation of forest loss and the socioeconomic drivers of land use change  Modeling of deforestation  Analysis of the consequences of land cover and land use change in the form of climate change and change in distribution biodiversity  Biomass estimation  Gap analysis of effectiveness of the protected area network in conserving areas of importance for biodiversity conservation (Shaily menon et a 1997)

Three geographical areas are focused upon to support the study of deforestation in India and its effects. These areas are the Western Ghats; Nawarangpur, Orissa; and North Eastern states of India.

Western Ghats

These are mountain ranges which run 1600 km along the west coast peninsular of India encompassing the states of Maharashtra, Goa, Karnataka, Tamil nadu and Kerala. These mountain regions have unique climates and they sustain various species and habitats of unique animals and plants. (C. Amarnath et al 2000)

The rate of deforestation is very high here because of rapid transformations like agriculture, monoculture , hydroelectric projects, mining etc. It has also become a biodiversity hotspot.

Remote sensing data consisting of biological and physical data of multiple dates is analyzed using GIS technology to assess the concern over biodiversity conservation and deforestation.GPS technology was used for field/ground data to enhance accuracy. Spatial data obtained from thematic maps, topographic maps, aerial photographs, satellite imagery(Landsat TM, IRS -1D) and field studies was analyzed on GIS to examine patterns, processes and consequences of deforestation. Spatial data when integrated with socioeconomic data reveals the reasons behind the land use changes. Buffer analysis was performed to examine relationship of forest loss with the road network, reservoirs and population centers. Human activity with grazing animals greatly contributes to quick depletion of forests.(C.S Jha et al 2000)

For a 70 year period(1920-1990), 40% of natural vegetation was lost or converted into open/cultivated lands, Coffee/tea plantations, and hydroelectric reservoirs. Deforestation has resulted in landscape and forest fragmentation (major cause of biodiversity destruction). Also land use changes and forest degradation have impacts on emission and sequestration of green house gases which leads to global climate change.

Nawarangpur district, Orrisa

Orissa is a state located in the eastern part of India. A tropical region with Sal mixed moist deciduous and Sal mixed dry deciduous forests. Nawarangpur covers an area span of 5,921 square km.The majority of the population consists of various tribal groups. It has a dry and sub tropical humid climate and an abundant forest consisting of unique and valuable medicinal plant species.

For GIS and remote sensing, Landsat MSS (1973), Ladnsat TM(1990) and IRS P6 LISS III (2004) satellite imagery are used to survey and assess the land cover, land use change and extent of deforestation from 1973 to 2004. Images collected from various satellites are fit to standard resolution to classify the non-forest areas within forest areas to estimate forest fragmentation. Forest management maps, Survey of India topographic maps, thematic maps and GPS are used for the precision of data. Ortho-rectified photos from Landsat data are downloaded from Global land cover facility to precisely measure the change. False color composite (FCC) using multiple spectral bands combination is also included with sub pixel accuracy. (C. Sudhakar Reddy et al 2009)

Deforest assessment

Changerate = [Ln(At1) – Ln(At0)] X 100/ (t1 – t0)

Where, At1 is area of class in current year, At0 is area of class in base year, t1 is current year, t0 is base year and Ln is natural logarithm.

For a 31 year period (1973-2004)- It is observed that there is a decrease in dense forest, increase in agricultural land, degraded areas of abandoned agricultural and unproductive scrub. The dense forest area in 1973 was 1,931.2 square km of total 5,291 sqaure km of area of study which later in 2004 was shrunk to 613 square km. An increase in open forest and in non-forest area was observed. Hence, rate of deforestation was increased from 6% (1973-1990) to 7.68% (1990-2004). Deforestation has become an increasing concern for Nawarangpur district.

North East States

The North East region of India is comprised of 7 states – Meghalaya, Arunachal Pradesh, Mizoram, Assam, Tripura, Nagaland and Manipur. Cherrapunji, Meghalaya has one of the highest average annual precipitation levels recorded (Guiness book of world records). The geographical location of these states boasts a very unique environment for many rare and endangered species of flora and fauna. These exceptional attributes of the North Eastern states of India qualify them as a global biodiversity hotspot. The region expands up to 225,083 square kms and supports 25% of the country’s entire forest cover.

The North Eastern states of India are facing the same global deforestation challenges. The lush green forests are under anthropogenic activities pressure. The economy boom has accelerated human expansion process leading to shrinking of these dense humid forests sustaining many forms of lives.

For 27 years (1972-1999), with the help of GIS and remote sensing using 6 temporal (Landsat and IRS satellite imagery) data sets based on satellite interpretation and geospatial data base, analysis of forest cover change, assessment of the extent and rate of change and identification of areas under constant or repetitive change are conducted. Maps are acquired, scanned and geo-referenced converted into digital database of ERDAS imagine 8.7 and ArcGIS 8.3. It is observed that there has been an intense land cover change because of timber collection, sifting agriculture, permanent agriculture, plantations, mining, city expansion etc. Forest fragmentation has increased ultimately leading to . (Nikhil lele et al 2009)

On the other hand, Arunachal Pradesh has shown positive signs of forest cover increase in last 10 years not only because of its almost inaccessible terrain but because of timely monitoring of land use and land cover, and by taking desirable measures in improving environmental policies and enforcing strict laws.

To summarize, increasing loss of dense green forest is a significant problem in India caused by primarily human activities. There are a very few dense forests left in the world covering up to 30% of total land area. Each year 16 million hectare of forests disappear. According to The World Resources Institute only about 22% of the world's original growth forest cover remains intact and most of this is located in the Canadian and Alaskan boreal forest, the boreal forest of Russia, and the tropical forest of the northwestern Amazon Basin and the Guyana Shield (Guyana, Suriname, Venezuela, Columbia, etc.) (http://www.globalchange.umich.edu/)

Remote sensing and GIS technology when used to its full extent can help us in guiding our future decisions for land use and land cover change. Technological advancements have made timely monitoring very fast and efficient. Easy and cost effective access of various type of the Earth related information is readily available and can be altered as per user specifications.

Information, policy and participation are essential components of any sustainable development. Information is the basis of planning and decision making which can be collected from various available sources (NASA, NOAA, IRS etc.).Policies made on International, national, or local levels should be simple and unambiguous, and should be enforced for sustainable planning and utilization of natural resources. Participation of people by raising environmental awareness at all levels should be necessary. Technology is the greatest tool in human hands that can be used for allocating protected land areas and monitoring the land use changes. Deforestation can be controlled and reduced by timely monitoring of land use around the world, A strong commitment to aforestation will reduce the environmental disturbances or mistakes made in the past for a promising future for all life forms.

Annotated Bibliography

Andrew K Skidmore, Wietske Bijker, Karin Schmidt and Lalit Kumar. “Use of remote sensing and GIS for sustainable land management.” ITC Journal (1997): 302-315 PDF

This research paper focuses mainly on GIS and remote sensing technology used for sustainable land use and management. Data collection using radar, hyperspectral remote sensing and high spatial resolution imagery is explained. Different sensors produce unique data sets for various land covers. Microwave, Infrared Radiation, UV radiation which are beyond visible light produces False Color composite images. They can provide information even when there are limitations like cloud cover, night darkness, sun spots etc. Various GIS applications and procedures can easily overlay these datasets in the form multiple layers unfolding valuable information for conservation and management of land cover and land use.

C. Sudhakar Reddy, K. Ram Mohan Rao, Chiranjibi Pattanaik, P. K. Joshi. “Assessment of large- scale deforestation of Nawarangpur district, Orissa, India: a remote sensing based study.” Environ Monit Assess (2009): 325–335 PDF

This research paper focuses on the study conducted between 1973 and 2004. Forest cover changes in 31 years was depicted accurately by employing data from Landsat MSS, Landsat TM and IRS P6 LISS III satellite imagery and using GIS procedures. Deforestation happening even in protected areas by human encroachment was clearly shown. The decline in forest cover was alarming. Land use changes have taken greatly place near road networks, water bodies and near the suburbs of cities. Spatial correlation and Buffer application clearly supported the human activities causing deforestation. Deforestation rate has been increased from 6% in 1973 to 7.68% in 2004.

Nikhil Lele · P. K. Joshi. “Analyzing deforestation rates, spatial forest cover changes and identifying critical areas of forest cover changes in North-East India during 1972–1999.” Environ Monit Assess (2009):159–170 PDF

The 7 states of the North East region of India was studied for land use and land cover change. Remote sensing and GIS technology plays a pivotal role in allotment and protection of forests in these states. The main causes behind deforestation in these areas were agriculture, plantations, hydroelectric projects, and mining. This area is a biodiversity hotspot; therefore it is rich in unique plant and animal species and habitats. Deforestation has exposed these fragile environments to high risk levels of endangerment and extinction. As most of the states showed rapid reduction of forest cover, Arunachal Pradesh showed signs of hope by increase in the forest cover. This was made possible by technology and strict law enforcement.

Shaily Menon and Kamaljit S. Bawa. “ Application of geographic information systems, remote sensing and a landscape ecology approach to biodiversity conservation in the Western Ghats”. Current Science Vol.73 (1997): 134-145 PDF

This research paper focuses on the usage of remote sensing and GIS technology in assessment of deforestation and conservation of protected land. It heavily emphasizes on the benefits and easement of using latest monitoring and analyzing data technology. Data obtained from various satellite imagery sources are put together in GIS though various procedures like Spatial correlation, geo modeling, 3-d draping of vegetation and digital elevation models. Satellite imagery with improved high resolution has made mapping and monitoring of land use and land cover easy, efficient and cost effective. It was observed that deforestation occurred heavily around the human settlements.

S. Jayakumar, D. I. Arockiasamy* andS. John Britto. “Conserving forests in the Eastern Ghats through remote sensing and GIS – A case study in Kolli hills.” Current Science (2002) :1259-1267 PDF

This research paper focuses mainly on the regions covered by the Eastern Ghats of India. Landsat TM, IRS 1C LISS III were the main sources of satellite imagery datasets incorporated with GIS mapping techniques. Forest area under high risk (2%), medium risk (25%) and low risk (69%) of deforestation were calculated. It was observed that area under High risk factor was near human settlements. The easy accessibility to forest areas was directly responsible for the degradation and of the land use change. Areas which are not easily accessible showed richness in plant and animal species.

C. S. Jha,C. B. S. Dutt, and K. S. Bawa.” Deforestation and land use changes in Western Ghats, India.” Current Science (2000): 231-238 PDF

This research paper focuses on the study of causes and results of forest cover reduction between 1973 to1995 in the Western Ghats of India. 25% forest was lost within 22 years in the area of study. Datasets from Landsat MSS, IRS 1B LISS -1 satellite imagery were obtained from NRSA. Multispectral sensitive data was used to estimate the impacts of deforestation in the Western Ghats of India. Rapid reduction in endemic plant and animal species was one of the deleterious effects of non-sustainable land use change like agriculture, plantations, land encroachment in protected areas etc.

G. Amarnath, M.S.R. Murthy, S.J. Britto, G. Rajashekar, and C.B.S. Dutt. “Diagnostic analysis of conservation zones using remote sensing and GIS techniques in wet evergreen forests of the Western Ghats – An ecological hotspot,Tamil Nadu, India.” Biodiversity and conservation (2003): 2331-2359 PDF

This research paper focuses on remote sensing and GIS techniques used in conservation areas of the Western ghats, Maps were prepared and studied using IRS LISS III satellite for assessment of patch size, shape, porosity and land cover diversity. Through Spatial analysis matched with phytosociological information collected from field. Forest fragmentation effects were taken into considerations which are responsible for biodiversity loss. Impacts of deforestation were concluded for this biodiversity hotspot. Conservation of these fragile environments was strongly recommended to curtail biodiversity loss.