The district sits on a total land size of 939.3 km2. Of this land, 91% is arable land, 5% is swamps and running water and a further 4% comprises forests and forest reserves.
The topography of Zombo is generally hilly steep U shaped and V shaped valleys. This is visible in all the Subcounties. The highest peak is on Agu Hill in Abanga Subcounty. The hills are characterized by undulating ranges sweeping across the Subcounties of Paidha, Abanga, Jangokoro, Zeu, Kango and recedes towards, and into, Arua District. A similar pattern is exhibited in Nyapea Subcounty running almost parallel cutting through Nebbi and Arua District. The major hills are Got Agu, Got Nyapea, Got Zeu, Got Azi, Got Ajere, Got Zamba and Got Afere.
There are stretches of flat lowland in Angol and Anyola parishes in Atyak Subcounty, the transitional landscape from hilly, highlands to flat, lowlands of Padyere and Madi-Okolo counties of Nebbi and Arua districts respectively. The transition is characterized by a steep escapement of Rift Valley origin on the eastern margins of Nyapea and Atyak Subcounties’ borders with Nebbi and Arua.
The multiple hills of Zombo district have limited land for arable agriculture forcing the population to cultivate the hillsides thereby contradicting good practices in soil management. Zombo district being a typically cultivation-agriculture-based economy, the people have to cultivate at all costs yet the available land are mostly the hill tops, slopes and valleys. In addition, in the quest for fresh grass for the few livestock, hunting and land clearing, the population have time and again been burning the vegetation along the slopes and on the top of these hill, posing further deterioration to the environment.
The common soil types are red and dark clay and loamy soils that are mature and fertile. The red soils are commonly found on the hill slopes and are muddy clay with high retention capacity for water that make the roads along the hill sides difficult to navigate by motorists. The red muddy soils are equally difficult to cultivate and thereby presents a hindrance to the local population engaged in peasant agriculture for their livelihood. On the other hand, the dark loamy soils are very fertile and are found commonly at the foot of the hills and highlands. This soil type has contributed to the steady and reliable supply of foodstuffs like Irish Potatoes, Maize, Cassava, Ground Nuts, Soya Beans, Beans, sweet Potatoes and vegetables like Tomatoes, Cabbages and Onions across the district. It is believed that the soils could have come as a result of past tectonic activities at the time of the formation of the various hills.
Other soil types in the district are the grey, skeletal and sandy soils mostly found in Paidha Sub county and parts of Abanga and Zeu Subcounties. The soils are extensively drained with very low pits and high organic matter. This soil type is also fertile and productive. However, due to numerous human activities such as poor farming methods, deforestation, bush burning, brick laying, quarrying and sand mining, the soils are being degraded at a faster rate.
Land use types
The various land use types in Zombo district include; Environmental (Agriculture approx.84%, forestry), Infrastructure (roads coverage, communication networks, electricity, water supply), Settlements, industrial, institutions (pre-primary, primary, secondary, tertiary, health centers, religious institutions, civic), recreational.
Climate and general meteorology
Zombo District experiences largely tropical climate, and in some cases bordering temperate climate due to her location within the Eastern topographical rainfall zone. Rainfall is bi-modal in nature with peaks in May and October. The fast short and usual unreliable rainfall is from late March to May, while the second and more reliable rain falls in July- October period. Dry spells are experienced in June- July and December to early March. Temperatures are generally low throughout the district, especially during the rainy period. These weather pattern however feature frequent overlaps and intersections, in some cases there are longer sunshine and dry periods, while in other cases, rainfall occur practically all the year round.
However, human activities have affected climatic condition, through deforestation, bush burning, and charcoal burning among others.
The District is mostly covered by Savannah grassland, and open grassland. The district is endowed with tree species such as eucalyptus, pines, cypress, grevellia, terminalia, combretum, to mention. However, the fairly high population density in the District has adversely effected the original vegetation. Wooded lands are being cleared for agriculture, to provide construction wood for the (semi-permanent) dwellings and wood fuel which is used by 99% of the population.
A lot of the natural vegetation has been depleted. It is not uncommon today to see bare hilltops and slopes, with scattered acacia and other tree species and shrubs, a scenario which was uncommon, unseen and unheard of in the past. These are evident in the Sub Counties of Nyapea, Atyak, Paidha and Kango among others.