Land Complex Classification of the Mula Area, Murcia Province, Southeast Spain

Abstract

This paper which summarises part of the 1976 M.Sc. thesis of the author (Astaras 1976), describes the results of a survey carried out in the Mula area of Murcia Province, southeast Spain. It was a preliminary integrated survey for mapping and describing the main natural resources of the Mula area. The work was based upon the integrated survey concept in which the whole complex of the land was examined rather than its individual elements.The method used was “the site analysis approach of Wright” (1972a, 1973). This was a method with similar objectives to the C.S.I.R.O. surveys (1963, 65, 68) but employed different procedures. Instead of subdividing a large area (land system) to particular smaller areas (land units), Wright advocated a synthetic method whereby details are defined for site units before these are grouped together to form the equivalent land complexes. Geomorphological criteria were used in site delimitation since landform characteristics are more readily perceived and measured than other terrain features (soil, vegetation characteristics) both on the ground and from airphotos.The study area was differentiated into “land complexes” which were the basic mapping units. Data were collected within geomorphological “sites” - near planar or regurarly curved slope units - which were combined into “site types”, each comprising a number of individual sites with closely similar gradient and curvature and with distinctive soil and vegetation characteristics. Spatial assemblages of sites characterised by specific site types were then delimited as “land complexes”.The survey area has been differentiated and mapped into seventeen land complexes. Each land complex is described in tabular form and is illustrated by block diagram to show the character and spatial relationships of the constituent site types. Then, the land complexes were themselves grouped into five broader terrain classes according to major landform type, relief amplitude and characteristic gradients.From the use of fieldwork data, the block diagrams and detailed tabular form descriptions of each land complex, and airphoto interpretation, terrain, soil, geology and surface materials, and vegetation - land use maps have been produced.Finally conclusions are drawn about the land complexes and the interelationships between, relief and surface materials, soil and vegetation and land use between and within land complexes.The value of a geomorphological site analysis approach by an interdisciplinary team of specialists (integrated survey) has been pointed out as well.