DESERTIFICATION MONITORING SYSTEM OVER SAHELIAN REGION OF NIGERIA
Desertification is a global environmental problem. It is defined as land degradation in arid, semi-arid, and dry sub-humid areas resulting from various factors including climatic variations and human activities (Olagunju, 2015). Desertification, land degradation and drought, whether driven by human actions, biophysical factors or a combination of these, result in loss of or damage to natural capital and social welfare. Land degradation reduces the value of soil, water, plant and animal resources to society, including the contributions of ecosystem function and processes to primary production and related industries. It also reduces the quality of ecosystem services and the levels of biodiversity in natural and transformed systems (UNCCD, 2013). It was in appreciation of the socio-economic importance of desert encroachment in the Sahelian states of Nigeria that the Director/Chief Executive constituted a research team under the leadership of the Head of the Research and Development Division of the Centre to investigate incidences of desert encroachment.
The objectives the team were mandated to achieve include:
(i) Identify, map and quantify the approximate study area
(ii) Continuously measure parameters (Pressure, temperature, humidity, wind- velocity and rain rate).
(iii) Analyse data obtained and ascertain if desertification is occurring or not.
(iv) Model possible rate, volume and direction of future encroachments
(v) Generate a hazard map for affected regions.
The research team held a series of pre-field meetings in Ile-Ife before setting out. Three (3) local government areas (Illela, Gada, and Tangaza) in Sokoto State were identified from literature, maps, and discussions to be undergoing desertification. The meetings were also to fine tune logistics arrangement in preparation for site visit. The team left Ile-Ife for Sokoto on January 23, 2017.
On arrival in Sokoto, the research team held meetings with representatives of the Usmanu Danfodiyo University (UDUS).
Ciroman Illela, Mukhtar Tukur Abdulrahman was mandated to take the team to the locations facing the menace of sand deposits. The team thereafter administered questionnaires on the people of Illela. Focus group discussions were also held to incorporate local knowledge and deduce the behaviour of sandstorms, dust storms, and sand deposition.
The team then visited Government Day Secondary School, Illela, where there were noticeable dune sites in the school. Very high wind speed lifting up sand particles were observed. The school authorities are making efforts to combat these observable desertification characteristics by planting neem trees to serve as wind breakers. Sand samples were collected from the sand dunes in the school premises.
The team was then taken to a village called Kalmano and met with the village head and some of the village elders. Although the village head in an interview admitted that sand deposition was intermittent, a major tragedy here was that Lake Kalmano which hitherto served as a source of their livelihood had dried up.
Further findings revealed that the lake was fed by River Magiya Lamido from Niger Republic. Unfortunately, the government of Niger dammed the river, thus cutting off supply to Lake Kalmano. The villagers now resort to digging boreholes for irrigation and dry season farming.
The team visited Gada local government area where it also paid a courtesy visit to the Chief of Gada, Alhaji Muhammed Kabir Kyari. The royal father expressed joy at the effort of the team and assured them that the people of Gada, who are hardworking and industrious, will render to them all necessary assistance.
The team was also received by the Vice Chairman of Gada local government area. Questionnaires were administered on the Vice Chairman and some of his councillors.
The team was then taken to Sabon Gari Gidan Kaura. Here, the team found that the old settlement called Kaddi Tudu had been submerged by rapid deposition of sand dunes leading to loss of lives and property.
It was as a result of this tragedy that the community re-settled in Sabon Gari Gidan Kaura. Enormous deposits of sand dunes with elevation of 338m were observed which contrasted sharply with the new settlement with elevation of 284m.
Questionnaires were administered on the inhabitants of the village and focus group discussions took place both on the sand dune hills and within the community. The team also took sand samples at different points and depths for further analyses.
The team was in Tangaza local government area for three days where it was joined by Mallam Umar Sani, a staff of the Agriculture Department of the local government who acted as a field guide.
In Ruwawuri, the team was received by the village head, Alhaji Usman Abubakar. The team held focus group discussions and also administered questionnaires on the locals.
The next day, the team visited Sarma Tudu, Tangaza local government area and was received by the village head, Sarkin Gabas Adamu Sarma Tudu.
During the FGD, the team was informed that deposition of sand takes place intermittently, sometimes destroying crops.
There is a seasonal lake in the village called Lake Karereyi. The team was taken to the lake site, being dry at this period of the dry season. Questionnaires were also admininstered both at the lake site and within the community.
The third point of call was Tsoni Gabas village where it was received by the representative of the village head, Mallam Jadi Ibro.
Here, the team found a fresh layer of sand deposits and upon investigation, discovered several layers of sand deposition. Deposition of sand here was found to be as a result of hills, mountains and fences acting as barriers, hence precipitating deposition.
Sand samples were taken from the different layers of deposition.
On completion of the field work in the three (3) local government areas, the team had a series of meetings at UDUS with some Professors in order to evaluate the field exercise, brief them and to get a benefit of their knowledge and experience. The meeting also enabled the team to source for baseline data relevant to its work.
The team held a meeting with Professor Sadiq A. Yelwa of the department of Geography, UDUS. The team briefed him on the field work and also sought his assistance on obtaining the vegetation and soil maps of Nigeria.
The professor lamented the lack of funds that would have facilitated the production of the vegetation map of the country. He nonetheless advised the team to put in place the modalities for a proper collaboration between ARCSSTE-E and UDUS.
The team also called on Professor Ajanaku of the department of who showed interest in the project and expressed his readiness to assist in anyway. He also informed the team that he was in the process of producing a soil map for the country and that the map production may likely be completed by June of this year (2017).
The team obtained some relevant data from him. Dr Murtala A. Gada, who was part of the field team, provided the team with relevant soil data of Sokoto State.
The field work carried out in the three local government areas confirmed that there is intermittent deposition of sand which destroys crops and is therefore a menace to agriculture which is the mainstay of all the communities visited.
This affects both the environment and socio-economic development of the people living in the areas surveyed. If left unchecked and unmonitored, this situation may lead to desert encroachment with all its attendant implications for the socio-economic life of the communities and the environment.
There is, therefore, an urgent need to move to the phase two of this project.