PHYSICAL SETTINGPost Comment PHYSICAL SETTING Nigeria
Relief and Drainage: The state may be divided into three topographic regions. West of the River Benue, covering mostly Ibi and Karim Lamido Local Government Areas, are the extensive Fadama swamps of the Muri plains. This region is very thinly settled and virtually uncultivated.
Specialist Hospital, Jalingo
A marked contrast to the floodplains is the undulating lowland of the eastern Muri plains. This is broken intermittently by high rising hills such as the Kungana, Fali and Bali hills which developed on sandstones. Standing above the 350m contour, the hills are developed on both sedimentary and crystalline rocks.
Usually, hills on sedimentary formations tend to have flat tops due most probably to lateritic capping. On the other hand, the hills which s developed on crystalline rocks consist of dome shaped inselbergs. The Mambilla Plateau is a unique topographic region with some of the largest and highest mountains in Nigeria, with peaks reaching over 1840m. The Chabbal Hendu, for example, is over 2000m above sea level.
The Plateau which developed on basement complex rocks, measures about 96km along its curved length and 40km wide, and bound ed by an escarpment which is about 900m high in some places. The Mambilla Plateau forms the watershed from which the major drainage systems in Taraba State take their source. Rivers Benue,Donga and Taraba (from which the state derives its name) are the dominant drainage systems which flow across the Muri plains to drain the entire state.
Main Roundabout, Wukari
Together with the minor ones, such as the Lamorde and Mayo Randewo, they form extensive flood plains in the central part of the state, providing suf ficiently fertile agricultural land which is presently underutilized. The undulating hilly surface of the plateau is uniquely attractive for its scenic beauty.
The bas ketofegglike surface of the plateau with its blend of evergreen lowgrowing grass vegetation, neatly demarcated into some kind of ranches/grazing reserves, and the sharply meandering road with hairpin corners across hill slopes, ravines and deep gorges, make driving to and from the plateau most astounding and interesting to a visitor.
Climate: Like most parts of northern Nigeria, Taraba State has a wet and dry climate. The wet season lasts, on the average, from April to October. Mean annual rainfall varies between 1058mm in the north around Jalingo and Zing, to over 1300mm in the South around Serti and Takum. The wettest months are August and September.
The dry season lasts from November to March. The driest months are December and January with relative humidity dropping to about 15 percent. Mean annual temperature around Jalingo is about 28°C with maximum temperatures varying between 30°C and 39.4°C. The minimum temperatures range between 15°C to 23°C. The Mambilla plateau has climatic characteristics typical of a temperate climate.
Temperatures are tow throughout the year and the rainy season lasts from February to November with a mean annual rainfall of over 1850mm. Vegetation: Rainfall distribution and topogra phy are the most important factors influencing the pattern of vegetation in Taraba State. The vegetation may be classified into three broad types: the Northern Guinea, the Southern Guinea and the Mountain Grassland and forest vegetation.
The boundary between the Northern Guinea and Southern Guinea corresponds fairly closely with the 1400mm mean annual rainfall isohyet, while the mountain forest and grassland vegetation occur mainly on the Mambilla plateau. Most of the lowland area is made up of ferruginous tropical soils which developed on crystalline acid rocks and sandy parent materials. The upland areas, especially the Mambilla Plateau, are covered by humic ferrosols and lithosols which are highly weathered and markedly lateritised, due to leaching.
Ecological Problems: Excessive deliberate bush burning, soil erosion, desertification and river blindness (onchocerciasis) are among the most adverse ecological problems in the state. From December to February (during the peak of the dry Harmattan season), a large part of the natural vegetation especially in the northern part of the state, is easily turned into an ash laden, dark looking wilderness of burnt vegetation, posing serious threat to livestock rearing activities in the state. Bush burning, fuelwood exploitation and the traditional slash and bum agriculture practised by the peasant farmers are gradually but consistently causing desertification and soil erosion especially in the northern part of the state.
River blindness is another major environmental problem in the state. Onchocerciasis is particularly a serious health hazard in the Gashaka, Bakundi and Gassol districts. It is a form of filariat disease caused by a nematode (fly) called Onchocerca volvulus. The vector (called the black fly), takes advantage of the fastflowing sections of rivers, such as rapids or rock surfaces, as breeding grounds.
Such conditions are provided by River Taraba which in fact traverses the three districts of Gashaka, Bukundi and Gassol, in the Gashaka, Bali, and Gassol LGAs. It has been speculated that the Taraba river valley may be one of the worst Onchocerciasis zones in West Africa. The socioeconomic consequences of onchocerciasis on the people of Taraba State is enormous.
The disease has affected between three to fortyeight percent of the productive age groups of the population living near the river valleys in these districts. It also reduces the economic productivity of the rural dwellers and undermines primary school enrolment and school attendance. In many cases, it results in the complete abandonment of a whole village for fear of the disease.
The Federal Ministry of Health and the state govern ment, in collaboration with AFRICARE (an interna tional nongovernmental organisation), are, however, working seriously to control the incidence and reduce the effects of onchocerciasis in Taraba State. While measures taken so far are mainly direct ed at attacking the direct causal agent of the disease, the focus of government in the new millennium should also be directed primarily at environmental education, awareness and control within the affected communities.