Why does a parcel of productive land become fallow over time? How is it that a parcel of wasteland remains in that state for so long? Today, these are the kinds of issues confronting decision makers in regional development. Land management is a highly complex activity, requiring a balance between diverse aspects of the natural environment and competing human interests.

In India, a district forms an ideal administrative unit for land use planning. All the 500 districts in the country undertake an annual planning exercise which lays down the programmes to be implemented in the upcoming financial year. Many researchers and policy advocates have examined the functioning of this meso-level planning in India.

Among the several aspects which require to be addressed is the content of a district plan. Upto now, this planning has largely been financial in nature, leaving out crucial aspects of land use planning. The Environment Systems Branch of Development Alternatives undertook a comprehensive project on district level planning and has attempted to correct this serious shortfall and make district planning more effective.

One part of the project was to prepare a development strategy for Datia district in Madhya Pradesh. This exercise involved making an inventory of the natural resource base as well as profiling the socio-cultural and economic practices of the population. The resource inventory was done though digital interpretation of satellite images, backed up by ground truth verification. From this, we prepared thematic maps of present land use, soil classification, land capability classification, geohydrology and soil irritability at 1:250,00 and 1:50,000 scales.

Land use planning basically involved processing of such thematic data. The processing stage of our project required overlaying the thematic maps to prepare a potential land use map. The development strategy for Datia was based on this map.

Currently, map overlays and “scenario building” can be carried out using any of the Geographic Information System (GIS) packages available in the market. However, the paraphernalia and expertise required to use these packages are not accessible to a majority of decision-makers. For us, it was an opportunity to design and validate manual overlay techniques which are simple but reliable.

During this process, we developed an algorithm - a step-by-step means of co-relating complex data. This procedure evolved as we work with the light table and manual overlays, and enabled us to make a coherent whole of a huge mass of data. We have named this the Datia Algorithm for Land Use Planning (DALUP) and it can be effectively used for planning at a watershed or district level, with two or more thematic maps as inputs. However, this is still a first attempt, and will be undergoing further refinements.

The present land use map showed the current status of crop land, forests, watch bodies, wasteland etc. The soil classification map delineated ten different soil types in Datia - black, red, alluvial etc. The land capability classification (LCC) map showed the classification of soils as per its inherent characteristics, external land features and certain environmental factors. The geohydrology map had five classifications regarding availability of ground water.

You can begin to appreciate the number of variables: five each in geohydrology and land capability, and ten each for present land use and soil. Each map alone had over 70 polygons! Overlaying these maps would have been an enormous task for the human brain. Even hypothetically, the number of possible combinations of polygons which can be obtained by overlaying two maps is simply mind boggling. How could we crack the problem?

We started by taking the land capability classification (LCC) map as the basis for suggesting potential land uses. We soon ran into a problem-there were some polygons which were good for agriculture according to the LCC but did not have good ground water. It was evident that the ground water map had to be overlaid with the LCC. That appeared to solve the problem, but as we tried considering all polygons, we ended up suggesting agricultural crops on degraded forest land!

The present land use map had to be considered to avoid such mishaps. Thus the overlay emerging from soil and LCC maps had to be further overlaid with the present land use map. The polygons in the first set of overlays were themselves becoming difficult to handle, and the third overlay was making things impossible. The process had to be simplified, so it would not just be a one-time exercise. Otherwise next time around we would have to rediscover the whole process yet these!

This was the start of DALUP. We began with the understanding that land use planning involved moving from the current land use to an improved scenario five years later. The present land use map was analysed. It had areas which did not require a change in land use-for instance, good forest land and areas under double crop. These were called “no problem” areas. What required change were areas not being optimally utilised - degraded forests, wasteland etc. We referred to these as “problem areas”.

The map required yet another kind of classification. Within the problem areas, there were those polygons which could only have certain specified land uses, e.g. forest land cold have only forest species. Such areas were called “static areas”.

The “problem” and “static” polygons required management measures. The overlays were carried out for other “problem” polygons as described in the algorithm. The potential land use map which emerged from this exercise was based only on the status of natural resources. There are, of course, other constraints in any land use planning exercise - financial, institutional etc.

Algorithm
1.	Start	11.	Overlay with soil classification to get Ov1.
2.	Read legend items in the present land use, soil classification, land capability classification and geohydrology maps.	12.	Overlay Ov1 with land capability classification to get Ov2.
3.	Read polygons within each legend item.	13.	Overlay Ov2 with geothydrology to get Ov3.
4.	Read Truth Table 1 and Truth Table 2.	14.	Check with Management Table 2 for all combinations in Ov3.
5.	Take a legend item in present land use map.	15.	Store in potential land use map.
6.	Is it a problem area?	16.	Have all polygons in this legend item been considered?
7.	If no, go to 15.	17.	If no, take the next polygon and go to 11.
8.	Is it a static area?	18.	Have all legend items been considred?
9.	If yes, check with Management Table 1 and go to 15.	19.	If no, take the next legend item and go to 6.
10.	Take a polygon within this legend.	20.	Stop.
Explanatory Note
1.	Formulate Truth Table 1 showing the problem areas. A present land use map comprises areas which require management in order to change the existing land use. These are called problem areas.
2.	Formlate Truth Table 2 showing the static areas. A present land use map shows areas where only certain land use practices are possible. For instance, in forest land we cannot suggest agricultural crops. Similarly, for regional land use planning, existing urban areas can be assumed to remain static for a period of five years.
3.	Formulate Management Table 1 showing the options required for static areas which are also problem areas.
4.	Formulate Management Table 2 showing the potential land use options for different categories polygons in Ov3.
5.	All maps are of 1;250,000 scale.
Inputs
1.	Present Land Use Map.
2.	Soil Map.
3.	Land Capability Classification Map.
4.	Geohydrology Map.
5.	Soil Irrigability Map.
Assumptions
1.	Static land uses will remain unchanged for a period of five years.
2.	Potential land use map as obtained from the algorithm can be prioritised based on financial and other considerations to obtain a proposed land use map.
Limitations
1.	Socio-cultural and economic data has not been incorporated.
2.	Very minute polygos have ben adjusted during manual overlays iwthout any significant change in the output.
Outputs
1.	Proposed Land Use Map, 1997.
2.	Development Strategy based on the Proposed Land Use Map.

We evaluated the current financial resource availability with the district authorities. Based on that, the action programme was prioritised and a proposed land use map for 1997 was draw up.

Shown above is one of the maps in the Resource Atlas that we have prepared for Datia. The Atlas has maps on natural resource, socio-economic and infrastructure parameters. Such an Atlas can be of immense help in a district planning exercise.

The project team had an opportunity to validate some of the findings during a two-day workshop which held in Datia and had participants from government, research institutions and local NGOs.

As a follow-up to the workshop, we are now preparing the thematic maps at 1:50,000 scale. This would facilitate in the implementation process.

Through further applications, we would attempt to refine DALUP. The future versions would have to incorporate socio-cultural, economic and infrastructure parameters. This would put the planning process on a sounder and more responsive footing.