Bawku West District is one of the Thirteen (13) Districts and Municipals in the Region. The District is located in the north-eastern section of the Upper East Region. Zebilla is the District Administrative capital. It is bordered to the north by the Republic of Burkina Faso, to the east by the Binduri District, to the west by Talensi District and Nabdam District respectively and to the south by East Mamprusi District.
The district experiences a unimodal rainfall regime lasting 4 to 6 months and a long dry period of 6 to 8 months in a year. The average annual rainfall, temperature and relative humidity are 956mm, 34oC and 56% respectively, with potential evapotranspiration of more than 2882mm.There is therefore excessive evapotranspiration over rainfall.
The district’s vegetation is Sudan Savannah consisting of short drought and fire resistant deciduous trees interspersed with open savannah grassland. Grass is very sparse and in most areas the land is bare and severely eroded. Common grasses include Andropogan gayanus (Northern Gamber Grass) in the less eroded areas and Hyparhenia spp, Aristida spp, and Heteropogon spp. (Spear grass) in the severely eroded areas. Common trees include Anogeissus spp, Acacia spp (Thorn tree) and Triplochiton spp. Economic trees include Parkia filicoidea (Dawadawa), Butyrospermum parkii (Sheanut), Andansonia digitata (Baobab) and Ceiba pentandra (Kapok).
In most cases the vegetation is highly degraded by land clearing for farming, fuel wood harvesting, overgrazing, annual bushfires, and harvesting of poles for construction. The activities of illegal miners also contribute to the degradation of the vegetation in some parts of the district as most of these illegal activities take place on agricultural lands, and this therefore has serious implications on soil fertility for sustainable crop production
Relief and drainage
The relief of the district is generally flat to gently undulating. These plains are broken in some places by hills or ranges formed from either outcrops of Birimian rocks (greenstones) or granite intrusions. These ranges lie along the border with Burkina-Faso, north of Zebilla, and turn south-west from the Red Volta north of Nangodi in the Talensi-Nabdam District. The granite areas are generally low to gently rolling (120 – 255m a.s.l).
The features of the hills vary from place to place but generally they have steep rocky slopes and narrow valleys subject to high rates of runoff leading to flash floods, gully erosion and stream bank erosion. The district is drained by both the White and Red Volta and their tributaries. The rivers over flow their banks during the rainy season (June to September) but dry up soon after the season with disconnected pools of water in their beds separated by dry stretches of sand and rocks. During the dry season, the sand bars make it possible for people to cross the White Volta on foot or by motor cycles at Sapelliga, the Ghana-Burkina-Faso border.
Soils & general characteristics
The total hectarage in the district suitable and unsuitable for crop production is 58,406 and 336,687 respectively. The major soils mapped in the district belong to Luvisols, Lixisols, Leptosols, Gleysols and Fluvisols. Other less extensive soils include Plinthosols, Regosols, Vertisols and Cambisols. They are developed over granites, Birimian rocks and recent and old alluvia of mixed origin. Because these parent materials are coarse textured, many of the soils have predominantly light textured surface horizons (sandy) with heavier textured soils (clayey) confined to valley bottoms. There are also extensive areas of shallow concretionary and rocky soils, which have low water holding capacities and limited suitability for agriculture.
Most of the soils, having developed over thoroughly weathered parent materials, are old and have been leached over a long period of time. Their buffering capacity as well as caution exchange capacity is also low since their predominant clay mineral is kaolinitic, consequently, most of the soils are of low inherent fertility. The two most frequently deficient nutrients are nitrogen and phosphorus. The build-up of any amount of organic matter is constrained by regular burning of crop residues and/or competitive use of these residues for fuel, animal feed or building purposes. The low vegetative cover during the dry season also renders most of the soils susceptible to erosion during the rainy season. This, in turn, exacerbates the low fertility problem. The sustainability of good crop yields is therefore closely linked with careful management of the soils with the objective of preventing and controlling erosion, increasing their organic matter content (compost, crop residues, farmyard manure, etc.) and replacing and increasing plant nutrients lost through erosion, leaching and crop uptake.
The soils and water supply conditions of the district are directly related to the underlying rocks. The major rocks fall within the Birimian and Granitic geological formations.
The Birimian rocks, often associated with granites, consist of steeply dipping metamorphosed sediments and volcanics. The argillaceous rocks of the Birimian formation consist, among others, of phyllites, biotite schists and quartzites, some of which are found north of Zebilla, south of Sapelliga and around Zongoyiri area. The volcanic group consists of greenstones, hornblende schists and phyllites. The rocks occur as hill ranges found north of Zebilla (e.g. Kubongo, Widnaba and Komaka) and in Apodabogo. Deposits of gold reportedly underlie the Birimian formation north of Zebilla and south of Sapelliga. In the Widnaba-Teshie zone, illegal mining of gold (‘galamsey’) accompanied by serious land degradation is prevalent. Therefore, if the activities of these illegal miners in the district which is on the increase are not checked, further degradation of the land would have serious consequences on agricultural production and household food security in the district as most of these mining activities take place on agricultural lands. This would further worsen the poverty situation in the District since more than 80% of the population depends on agriculture for their livelihoods of which women are the majority.
The granitic rocks consist mainly of biotite and hornblende complex with potassium feldspars and sodium feldspars dominant in the biotite granite and biotite granodiorites respectively. These granites are coloured pink, coarse grained and potassium rich. The soils formed from these rocks are light textured and rich in potassium.
Date Created : 12/4/2017 7:01:51 AM