Kerala is endowed with a combination of distinct altitudinal variations resulting from the rise of the land mass from 5 meters below sea level in the west to the soaring heights of 2695 meters in the east within the short span of 120 km. The small expanse of land with an area of 38,863 km 2 has a base length of 560 km along the coast and width ranging from 11 km to 124 km. Physiographically, the terrain has three natural regions namely, lowlands, midland, highlands (Figure 1). Geologically, Kerala is occupied by four major rock formations namely, crystalline rocks of Precambrian age, sedimentary rocks of Tertiary confined to Neogene period , laterites capping the crystalline and sedimentary rocks and recent and sub recent sediments forming the low-lying areas and river valleys. There are sporadic Paleozoic granites and pegmatite and Meso-Cenozoic dykes intruding these rocks. The oldest rocks so far dated in Kerala are the charnockites, which yielded an age of 2930 +/- 50 Ma (Soman, 1997& 2002). The varied rock formations under different geological domains harbour different mineral deposits and the transformed rock strata stockpile copious groundwater resource. The state is gifted with ten soil types derived from the laterite base and has 12 distinct agro climatic zones. The undulating topography, vibrant climate and vivacious hydrology in the background of ever active tectonics resulted in 44 river basins, 1750 sub basins and 4452 mini watersheds providing multitudes of lively micro ecosystems. The environment of these micro watersheds are conducive to varying crop types, such as, coconut and rice in the sultry lowlands, rice, tapioca, banana, arecanut, coconut, pepper, cashew and rubber in hot humid midlands and tea, coffee and cardamom in the cool subtropic highlands. The micro ecosystems are such that the valleys with near waterlogged conditions for most part of the year are seen juxtaposed with dry hilltops decked with densely canopied trees.

Physiographic map of Kerala

Land capability

Considering the characteristics of soil, drainage/wetness, erosion, runoff etc., Kerala has 18 land capability subclass associations of five broad land capability (LC) classes (KSLUB, 1995 and 2002). The broad LC classes are Class II (Good cultivable land), Class III (Moderately good cultivable land), Class IV (Fairly good cultivable lands), Class VI (Well suited for forestry or grazing), and Class VIII (Land suited only for wildlife and recreation). The approximate area under each class is given in Figure. The soils of Kerala has limitations for sustained use under irrigation. Only about 37% of the area of Kerala is suitable for irrigation with certain limitations.

Land use

Kerala has a diverse land use and cropping pattern. The land reforms introduced in the State brought in radical and comprehensive institutional changes leading to drastic transformation in the land holding pattern. This has resulted in shift in the land use pattern. The existing pattern of land use of the State is given in Figure. Agriculture is the dominant land use type of the State. It accounts for over 55% of the geographical area followed by forest land (including degraded forest) of 28% but area under non-agricultural use is only 11% (Farm Guide, 2006). Classification of area under land utilization for the year 2006-2007.

  Mineral resources

The state is endowed with a number of occurrence/deposits of minerals such as heavy mineral sands (Ilmenite, Rutile, Zircon, Monazite, Sillimanite), Gold, Iron Ore, Bauxite, Graphite, China clay, Ball clay, Fire clay, Tile and Brick clay, Silica sand, Lignite, Limestone, Lime shell, Dimension stone (granite), Magnesite, Quartz-Steatite etc (Nair et al., 2005; KSLUB, 1995 and 2002). However, mining activities on large scale are confined mainly to a few minerals. The mineral distribution map of Kerala is given below. The reserves of various minerals and mineral production in Kerala are given in the Table below

Mineral reserves (2000-01)

Mineral map of Kerala (After Dept. of Mining and Geology, 2005)