Location: The state is located on the southern end of the High Plains of northern Nigeria, bounded by parallels 9°03'N and 11°32'N, and extends from the upper River Mariga on 6°05'E to 8°48'E on the footslopes of the scarp of Jos Plateau (Udo, 1970).
Emir's Palace, Zaria
Geology and Relief: The bedrock geology is predominantly metamorphic rocks of the Nigerian Basement Complex consisting of biotite gneisses and older granites. In the southeastern corner, younger granites and bathyliths are evident.
Deep chemical weathering and fluvial erosion, influenced by the bioclimatic nature of the environment, have developed the characteristic high undulating plains with subdued interfluves (Mortimore, 1970). In some places, the interfluves are capped by high grade lateritic ironstone especially in the Northwest.
However, rocky granitic residuals form inselbergs of varying sizes and shapes, and constitute the main local relief (relative relief is less than 150m) here and there with Kufena, Kagoro hills and Dutsen WaiKudaru Ring complex standing out very prominently. The valleys are shallow but wide, stretching several tens of kilometres into the headwater areas with gentle sloping valley sides; imperceptibly grad ing into flat moist to marshy alluviated bottomlands or floodplains, called "fadamas" in Hausa.
Although stream valley incisions and dissections of the high plains are evident in several areas, especially in the Zaria region, they are due more to anthropogenic influences and climatic factors than regional geologic instability.
Climate: Kaduna State experiences a typical tropical continental climate with distinct seasonal regimes, oscillating between cool to hot dry and humid to wet. These two seasons reflect the influences of tropical continental and equatorial maritime airmasses which sweep over the entire country.
Peugeot Automobile Car Plant, Kaduna
However, in Kaduna State, the seasonality is pronounced with the cool to hot dry season being longer, than the rainy season. Again, the spatial and temporal distribution of the rain varies, decreasing from an average of about 1530mm in Kafanchan-Kagoro areas in the Southeast to about 1015mm in lkaraMakarfi districts in the northeast.
High storm intensities (ranging from 60mm hr1 to 99mm hr1) plus the nature of surface run off build up the good network of medium sized river systems. High evaporation during the dry season, however, creates water shortage problems especially in Igabi, Giwa, Soba, Makarfi and tkara LGAs.
Soils And Vegetation: Generally, the soils and vegetation are typical redbrown to redyellow trop ical ferruginous soils and savannah grassland with scattered trees and woody shrubs. The soils in the upland areas are rich in red clay and sand but poor in organic matter.
However, soils within the "fadama" areas are richer in kaolinitic clay and organic matter, very heavy and poorly drained, characteristics of vertisols. Fringe forests ("Kurmi" in Hausa) in some localities, and especially in the southern LGAs of the state, are presently at the mercies of increasing demands for fuel wood in the fastgrowing towns and urban centres.