SOILS:
Arua district is underlain by Pre-cambrian rocks of Basement complex, which include granitic and metamorphic rocks. The rocks are composed largely of aplitic granulites, which generally form enclaves in the gneiss complex. These cover parts of Vurra and Ayivu counties. They are part of the tectonic groups.
A wide range of Basement rock type represented includes quarzites, schists, amphibolites, charnockites, phyllites, mylonites and others.
Other rock types of Cainozoic era are part of rift valley deposits of Pleistocene age, which occur in Madi Okollo county. Red course sands, silts and subordinate amounts of clay, gravel and diatomite, represent them.
Most of the hills are of inselberg type and rise abruptly from the plains as steep, bare marsses of fresh solid rock usually with no soil cover at all. Ollier (1960) described their formation.
On hilltops grey granite and gneiss are left exposed over wide areas. These gneisses and granites are intensively metamorphosed and deformed. Soil depth is not more than 15 Cms. However, it is fairly fertile along valleys due to alluvial deposits found on the lower portions of slopes.
The predominant soils are ferralitic and sand loams covering large areas in Arua district. These soils are fine textured with loose structure erodible and easily erodible and easily leached. Most soils are acidic.
Vertisols are found in the northwestern parts of the district. These soils have poor drainage and thus easily become water logged.
There is a lateritic layer in most soils. This reduces the rooting depth and moisture conditions, where it is close to the surface, making the land difficult to cultivate. Sub-soils lack minerals for plants. They are good for building/construction purposes. Soil types in Arua include: There is a lateritic layer in most soils. This reduces the rooting depth and moisture conditions, where it is close to the surface, making the land difficult to cultivate. Sub-soils lack minerals for plants. They are good for building/construction purposes. Soil types in Arua include:
• Yellow-red sandy, clay loam latosols varying from dark grey to dark brown which are slightly acidic and mainly derived from granite, gneissic and sedimentary rocks. They occur on gently undulating-hilly topography.
• Brown-yellow clay loams with laterite horizon with a variation of dark brown to dark greyish brown, which are slightly acidic. These occur on flat ridge tops or on top of undulating topography.
• Light-grey white mottled loamy soils with laterite horizon ground (water laterite), structureless loamy sands. They are acidic-alkaline and are mainly found on the lower and bottom slopes.
WATER RESOURCES:
Arua district generally lacks adequate surface and ground water resources. In Arua district the sources of water include ground water, rivers, springs, wells, gravity flow scheme. The coverage of water resources over various counties is fairly equal. Major problems attributed to water are only experienced in Madi-Okollo County where there are fewer water bodies and water quality is rather low.
Although the Nile is a very reliable water source and has attracted significant settlement pattern along it, it is not strategically located and covers less than 0.2% of the total area of the district. It benefits only Madi-Okollo County.
The Albert Nile is fed by streams and ground water during the heavy rains and loses its water during the dry season through evaporation and also to the surrounding unconsolidated sands, silt and gravel which recharge the water content of the surrounding countryside through natural means. Part of the Albert Nile is found in the east of the district. Other important rivers are Enyau, Jurei, Ala, Ora, Kochi which all drain into the Nile in the east. There are also numerous streams in the district.
WETLANDS:
Wetlands are vegetated areas of land that are flooded permanently or seasonally and stays wet long enough for certain plants and animals to grow even when there has been no rain. Wetlands are also defined as transitional lands between terrestrial and aquatic systems covered by shallow waters (SOER 1998). The water holding capacity and buffering effect of wetlands ensure that rivers and streams continue to flow during the dry season and ground water is also sustained. Wetlands also support a number of fauna and flora.
Wetlands cover approximately 2.8% (87 Km2) of the total land area of the district. This allows water to stay in one place long enough to maximize infiltration and thus access to water supplies for plants. There has however been a lot of encroachment on the wetlands for crop cultivation and unless the trend is reversed, the district’s wetlands will be completely destroyed in future.
In Arua district, the wetlands are being used for cultivation and livestock grazing crops such as sugarcane, yams, rice, maize, beans and sweet potatoes are grown at the edge of wetlands. During the dry season, grazing and watering of livestock mainly take place in the wetlands. Papyrus, reeds and similar plants are used for everyday necessities such as thatching, mats, baskets and other handcrafts. Palms and smaller sized trees are used as structural building materials.
Wetlands provide habitat for substantial population of fish, which have been caught for both domestic and commercial purposes. The fish species caught from the wetlands in the district include catfish (claricus), lungfish and Bagrus (catfish).
Other uses of the wetlands in the district include provision of water for domestic, hunting, sand mining The pressure can lead to ecological imbalances in wetlands as products are not used sustainably. There is no sound management of the wetlands and over-exploitation in some parts of the district. The most over-exploited wetlands in the district are in counties of Vurra and Ayivu. The policy, which discourages wetland drainage and conversion to unsustainable uses, should be enforced in the district.
Drainage is one of the major threats to wetlands in the district. Wetlands are drained for cultivation of vegetables, sugarcane, yams, maize and beans. They are also drained for excavation of clay for bricks making, sand mining and reducing incidence of mosquitoes breeding.
The main pressure on wetland is due to the location of factories near wetlands. Activities in these factories end up polluting the environment. Car washing directly in the river also pollutes the river. These factors disrupt ecological balances affecting the fauna and flora in wetlands, resulting in deterioration of the environment. To address the problem, land use should be properly planned. Feasibility studies of all projects and activities targeted around wetlands should be done before they are started. People should also be properly educated on land use in order to reduce environmental degradation of wetlands due to their activities.
Vegetation
The natural vegetation used to be characterized of open lands with equatorial type of savanna grasslands, with small pockets of natural forests on hills, especially along the northern parts of the district.
The original vegetation of Arua district was composed of mixed woody savanna, which has greatly been reduced by subsistence farming that currently occupies about 80% of the total land area.
Forests are an important part of the vegetation of Arua District. This is again divided into low and high altitude forests. But in Arua district the predominant type is the high altitude forests. The former are mainly found along valleys.
The Savanna by far is the predominant vegetation in the district. The vegetation is Butyrosparmum – hyparrhemia savana. It is characterised by such trees as Isobulinia doka, Danieh cliveer and Afzeha africana.
In the central parts of Arua, the vegetation consists mainly of butyropernum-Hyparrhenia Savana with dry hyparrhemia grass savana. Post-cultivation communities of Imperata-Panicum-Hyparrhenia and Hyparrhenia-Peridium are found on the lower ground. Palm savanna is found to the northeast. Also present are dry combretum Acacia-Heteropogan an d Butyrospermum-Hyparrhenia savana.
THE PEOPLE
The Lugbara, largely inhabit Arua District. They are the dominating settlers in all parts of the district. Other tribes are Kakwa, Madi, Alur and Lendu. The Madi live in the eastern parts while the Alur and Lendu are mostly found in the western parts of the District. The Lugbara and Madi are Sudanic origin while the Kakwa are Nilo-hamites. The Alur and Lendu are of Congo origin. All the ethinicities have similarities in culture.
