Top-down approach for generating spatial database at cadastral level-A Sikkim Himalayan experience

Top-down approach for generating spatial database at cadastral level
- A Sikkim Himalayan experience

Dr. Saurabh Gupta and Syed Taha Owais
NIC, Sikkim

Abstract
The present system of preparing and maintaining land records originated from Mughal period and reached its scientific form during the British rule. With passing of time, maintenance of these records has gone through a process of evolution as required by various socio-economic compulsions. In India, the planners have been very conscious of the fact that proper maintenance of land records is basis of good administration, aimed at social justice through better implementation of rural development programs. With this end in mind, the government has initiated a number of projects specifically related to land records.In the state of Sikkim, the computerization of land record is almost complete and online mutation process currently under progress in west district. The novel technology of GIS/RS is being actively employed at watershed level for developing micro-level planning models. In continuation, cadastral map of one block is digitized and resource management analysis is performed at plot level.

Introduction
Sikkim state is situated between 27⁰04' to 28⁰07’ North latitudes and 88⁰01’to 88⁰ 55’ East longitudes. The state is almost rectangular in shape and covers an area of 7096 sq. km. Nepal bound the state in the west by the vast stretches of the Tibetan plateau, in the north, in the east by Bhutan and Chumbi valley of Tibet and Darjeeling district of West Bengal stretches along its southern boundary.

The mountainous terrain of Sikkim consists of a tangled series of interlacing ridges, rising one above the other, from south to the foot of the high peaks that mark the abode of snow in the north. The entire state is covered with steep hills and deep valleys. The trend of the mountain system viewed as a whole is in a general east west direction. The general run of the main ridges is north-south with subsidiary interlacing spurs from each ridge in a roughly east–west direction. Main ridges in Sikkim run in more or less north–south direction. Sikkim is primarily the catchment of Tista drainage system. Tista River while flowing north to south divides the state into two parts. The river rises from north district fed by snows from Kanchenjunga: its other tributaries join it from Lhonak, Zemu, Talung glacier of Kanchenjunga group in the west. The chief tributaries of Tista – the Great Rangit fed from the snow of Narsing and Kabru peaks, south of Kanchenjunga. There are two predominant zones viz. Gnessic and Daling group and also with some intermediaries. Daling group consists of predominantly phyllites. At the boundary between this and gneissic rocks they pass into silvery mica schist. Dark clay slates with thick quartzite bands prevail in certain areas: silt stones and siliceous limestone is also found in certain areas.

The climate of the state varies generally from sub- tropical to alpine depending upon the elevation of the place. Within the same catchment watershed of a stream, sub- tropical or even tropical climate is often observed at the lower end of the watershed in the valley, while temperate climate prevails at the upper reaches of the stream. Sikkim is richly endowed with natural flora and fauna. The natural vegetation consisting of evergreen trees, grasses and bushes extends upto 5000m MSL only. At elevation above 5000m MSL hardly any vegetation is found. Distribution pattern of natural vegetation in the state may be divided into 5 mixed forest zones – Lower Hill Forest (<900m), Middle hill Forest (900-1800m), Upper Hill Forest (1800-2450m), Rhododendron and Oak Forest (2450-3350m) and Conifer and Alpine pastures (>3350m).

Administratively Sikkim has been divided in four districts namely North District, South District, East District and West District. Each District has further been divided into two subdivisions. Gangtok, Pakyong and Rongli in East district, Namchi and Ravangla in South, Magan and Chungthang in North and Gyalshing and Soreng in West. There are 12 major towns namely Gangtok, Namchi, Jorethang Soreng, Ravangla, Singtam, Pakyong, Mangan and Chungthang. There are 447 villages out which 440 are inhabited. A total of 405505 population was recorded in 1991 with an average density of 57 persons per square kilometres. Lepcha, Bhutias and Nepalis three major ethnic communities. Here. Lepcha and Bhutias are Bhuddists while majority of Nepalis are Hindus. Major population resided in East district followed by South district. Sex ratio in the state is 892 females per 1000 males. Amongst districts the highest sex ratio rate had been seen in West District with 919 females per 1000 males followed by South, East, North. STs are the major population spread in almost 98% of the revenue blocks.

State literacy percentage is 54.39%. Male literacy is 63.44% and female literacy is 44.06%. East district occupies first rank in literacy. It also boasts on two-degree college, one in Gangtok and another in Namchi. In the urban areas, Jorethang has highest literacy rate of 83.50% followed by Gangtok (80.18%).Industrially, Sikkim is a backward state. However, the government has adopted the philosophy of industrial development and as a result some cheese plant, dairy farms, bottling plants have come to existence. Besides this, tourism is the biggest industry.

Location and Extent of Study Area

Name of Study Area	Rate Chhu Watershed
Spatial Information Source	78/11, 78/15, Classified RS Image and Land Survey Map.

Geographical Location	27° 20’30’’ and 27° 30’30" North
	88° 33’57" and 88° 45’50" East

Total Area Covered	87.34 sq. km. (Spans calculated)

Spatial Information	Watershed map, contour map, forest density map (1988), land use map (1963), roads, settlement, river and drains and soil maps, streams maps and cadastral map

Present situation of land record in Sikkim is that out of 4 districts, attribute information related to land is almost complete in three districts. Online mutation is under progress in one district. Besides this, Land Revenue Department has two sets of survey records pertaining to the old survey 1952 and the second pertaining to the more recent survey of 1976-82. However, for various reasons, 1952 cadastral survey maps are reference point for solving land related litigations in Sikkim. There are near 4000 cadastral maps. Each village has around 3-4 maps. The maps of rural areas are 1 mile = 16’’ scale and that of urban areas are 1 mile = 64’’ scale.

In this case study an attempt has been made to develop necessary spatial database at the cadastral level and investigate into the resource distribution and utilization at plot level. In this study, cadastral map of Tintek block was traced and digitized and GIS based study performed.

In this study, a top-down approach has been adopted. Here top-down approach means, that first GIS based analysis is performed at watershed level for micro-level planning model, then at one lower level a cadastral level study is done.

The usual method adopted in development of Land Information System (LIS) is bottom-up approach that is several cadastral maps are digitized, geocoded and then mosaic together to generate village or block boundary. However this approach is more tedious and prone to errors as there is a very limited possibility of cartographic adjustment. But, in top-down approach, one has the village or block map as a reference, which can help in minimizing the geographic errors, and proper overlays can be obtained and hence maps can be cartographically adjusted. Besides this database development and implementation of pure LIS system can become much easier and realistic.

The above maps are forest, land use 1963, altitude classification and slope classification.

At the watershed, various models were also generated, like landslide model, erosion intensity model, change in land use pattern and cardamom cultivation potential model.

Thus the GIS concept was effectively used to develop resource mapping at the cadastral level and various models were generated by combining different relevant layers. Then finally cadastral maps were traced, digitized and brought into the GIS. The attribute data was integrated and various thematic maps were generated like holding by social group, holding by type and various models generated at watershed level were also mapped at the cadastral level. Thus we can see the advantage of the top-down approach. The models and maps are generated for large study area and these are then base-cut to the smaller study areas i.e., at the cadastral level.

Altitude	Area(%)	Cumm Area	Area(sq mi)
1000 – 1499	76.02	76.02	0.379020
1500 – 1999	19.26	95.28	0.096027
2000 – 2499	4.72	100.00	0.023530
Total		100.00	0.498577

Social Group	Area (%)	Cumm Area	Area(sq mi)
General	39.03	39.03	0.194598
Government Land	22.19	61.22	0.110654
OBC	30.36	91.58	0.151354
ST	8.42	100.00	0.041972
Total		100.00	0.498577

Change in land use is calculated for period between 1963 and 1988

Legend	Area (%)	Cumm Area	Area (sq mi)
Very Good	3.95	3.95	0.019714
Good	96.05	100.00	0.478863
Total		100.00	0.498577

Legend	Area (%)	Cumm Area	Area (sq mi)
High Risk	0.64	0.64	0.003180
Low Risk	94.01	94.64	0.468688
Very Low Risk	5.36	100.00	0.026709
Total		100.00	0.498577

Status of Land Record Computerization in Sikkim State
Sikkim has led by example in implementing IT on different areas of activities. Land Record is such an area, where it is in the forefront with the use of latest technology. NIC, Sikkim has joined hand in doing so. All the land records of the state have already been entered into computer and an instantly updating and querying software that developed by NIC, Sikkim has been implemented with the partial data. We are on the verge of full implementation of it. The concept and activities covered under this project have been discussed below.

Land owner’s name & his caste
Owners children’s name
Area of the land
Plot no. And khatiyan no.
Crops
Class & type of land
Address
Block, etc.

When a land is transferred from one person to another, it is done by means of registration (which may fall on sale, court decree, leased, donation) or inheritance (that’s parental land). Once it is transferred, it is required to update the land record with its new owner and Parcha (proof of ownership) is to be issued. This is known as mutation. The process of mutation is like this. When a person who has acquired a plot of land recently, comes to the Revenue Officer/Sub-Divisional Magistrate with an application to transfer the land in his/her name, the concerned office issues notices to check if any objection is there from third party. On reception of No Objection Certificate from all the bodies, the concerned office completes the process by updating the land record and issuing the Parcha. If the land was acquired by means of registration it may not require to go through the process of issuing notices and receiving NOCs, because that is done already in the process of land registration. On computerized system, one can make queries for any information pertaining to the land record. More over when it is linked with the Land Registration and GIS based cadastral maps of land, it will become a valuable asset to the state. Through which one can navigate through each plot of the land, can make specific queries (like the cases of registration pending, the revenue collected so far, the plan of revenue collection, the defaulters, no. of persons holding land more than 10 hectare, the contour of a specific piece of land etc.), and the process itself will become swift.

An Ideal Land Information System
From above discussion, we can conclude that combined power of spatial analysis and powerful RDBMS can help develop a working LIS. Our aim should not only be to digitize the existing cadastral maps, but also to plan our resources like forest, water, and irrigation facilities. The real affect can only be felt if using such a system we are able to suggest our farmers to cultivate a particular type of crop, when our revenue department can properly estimate the revenue to be generated and when a common man can easily settle his land related problems.

Conclusion
Thus it can concluded that a top-down approach to develop resource management mapping can provide following benefits

Geographic correction and cartographic adjustment is possible as one has the larger study area for reference
Once the cadastral maps are brought into the system, generation of other maps is not difficult as one has to only base-cut those earlier maps to the cadastral map.
Top-down approach also provides easier integration for attribute data because cadastral is confined to one village or revenue block.
Using top-down approach, the bottom-up approach as also be implemented as these cadastral can be mosaiced together to form village or revenue block map.