Harmonisation of land-use class sets to facilitate compatibility and comparability of data across space and time

Harmonisation of land-use class sets should consider both space and time, as the objective should include harmonisation of land-use change in order to analyse environmental processes and problems. Existing systems make only a limited contribution to data harmonisation and data standardisation as they contain many inconsistencies in the adherence to the fundamental principles of classification and use a variety of basic units of measurement, in addition to the lack of agreement on the definition of land use. Though the meaning of land use varies among sectors, the set of key parameters used is limited. Analysis of major existing class sets reveals that two parameters suffice: function that describes land use in an economic context and activity that is defined as the combination of actions resulting in a certain type of product. An example of land-use harmonisation in Albania illustrates how the creation of a reference system based upon the principles of classification, using the synergy between classification and information technology concepts and based upon the function and activity parameters can facilitate harmonisation between landuse class sets in parallel to achieving land-use change harmonisation. Comparison with remotely sensed based land-cover related land-use data illustrates that land use contains many aspects that go beyond land cover. Land-use change operates over a range of scales in space and time and analysis at different levels of data is necessary in order to detect the patterns at the different data levels. The way forward to harmonisation of land-use class sets is adoption of a parametric approach. Further research is necessary to define quantitative measures for the harmonisation result at class level and between two class sets.