Computer automation of land evaluation procedures

This study was concerned with the computer automation of land evaluation. This is a broad subject with many issues to be resolved, so the study concentrated on three key problems: knowledge based programming; the integration of spatial information from remote sensing and other sources; and the inclusion of socio-economic information into the land evaluation analysis. Land evaluation and land use planning were considered in the context of overseas projects in the developing world. Knowledge based systems were found to provide significant advantages over conventional programming techniques for some aspects of the land evaluation process. Declarative languages, in particular Prolog, were ideally suited to integration of social information which changes with every situation. Rule-based expert system shells were also found to be suitable for this role, including knowledge acquisition at the interview stage. All the expert system shells examined suffered from very limited constraints to problem size, but new products now overcome this. Inductive expert system shells were useful as a guide to knowledge gaps and possible relationships, but the number of examples required was unrealistic for typical land use planning situations. The accuracy of classified satellite imagery was significantly enhanced by integrating spatial information on soil distribution for Thailand data. Estimates of the rice producing area were substantially improved (30% change in area) by the addition of soil information. Image processing work on Mozambique showed that satellite remote sensing was a useful tool in stratifying vegetation cover at provincial level to identify key development areas, but its full utility could not be realised on typical planning projects, without treatment as part of a complete spatial information system.

Contracts for the sale of land and personal property:the equitable interests of the purchaser

As property lawyers, we are all familiar with the general principle that a contract for the sale of land, which is capable of specific performance, operates in equity so as to confer a trust on the purchaser pending completion of the sale. Although some controversy exists as to the exact nature of the trust, it is well established that, upon exchange of contracts, equity will ‘‘treat that as done which ought to be done’’1 with the consequence that the purchaser acquires equitable ownership even though full (legal) title to the land will not pass until completion (and registration). As land is unique, specific performance is readily available in the context of sales of land where damages would, clearly, not be an adequate remedy. The same cannot be said for contracts for the purchase of personal property where invariably the subject matter is not unique and where a substitute can easily be acquired in the open market. In circumstances, however, where the property is unique or scarce (for example, a rare painting or vintage car), the maxim that ‘‘equity treats as done that which ought to be done’’ may be invoked so as to confer on the seller an equitable obligation to transfer the property to the purchaser in fulfilment of the contract. Where, therefore, the contract is specifically enforceable in this way, the seller, it is submitted, will again hold the property on trust for the purchaser where, as in a contract for the sale of land, there is an interval between the date of the contract and completion of the sale. The notion that a seller holds personal property upon trust for the purchaser pending completion of the sale is admittedly controversial, but this article seeks to argue that the same principles governing equity’s intervention in sales of land should apply in the context of sales of personalty. It is submitted that equity’s role in imposing a trust on the vendor both in relation to sales of land and personalty may be important in safeguarding the interests of the purchaser prior to, as well as after, completion of the transaction.