CONSOLIDATION AND DISSEMINATION OF PROSOPIS MAPPING RESULTS
Aim: To consolidate the findings of the prosopis Landsat imagery mapping programme and disseminate these to national- and district-level partners
The objective of the prosopis mapping activity was to estimate and delineate, by use of remote sensing technologies such as Geographic Information System (GIS) and Global Positioning System (GPS), the area under prosopis colonisation. The mapping team, comprising of technical staff from CSDI and Kenyatta University, used FAO’s Africover land-use/land-cover data for the exercise. The districts covered in this programme were Garissa, Tana River and Ijara.
Maps estimating the area under prosopis coverage were developed as a result.
The mapping exercise was also able to pinpoint ‘problem divisions’ in terms of degree and extent of prosopis colonisation. In Tana River district, Wenje division was found to be most affected by prosopis colonisation, with 64.8% of the division’s 847km² under invasion. Forested areas, especially along the river Tana, were found to be under greatest risk of prosopis colonisation, with 52% of the riverine forest already under prosopis invasion. Road runoff was also found to be accelerating the rate of colonisation.
Three results dissemination sessions (titled “Managing the prosopis menace: Issues, options and challenges”) were held in Nairobi, Garissa and Tana River districts on diverse dates between November and December 2005. ALRMP and other partners in the drylands, including Kenya Forestry Research Institute (KEFRI), Kenya Agricultural Research Institute (KARI), National Museums of Kenya (NMK), CAB International and the Forestry Department attended.
One emerging issue out of the various stakeholder meetings was the need to develop prosopis management options that will convince pastoralists to take a leading part in controlling the spread of the species. Stakeholders also urged CSDI to develop long-term budget scenarios for more intensive engagement with the species, and a greater focus on the use of the species for honey production.
Biomass assessment for energy production
Aim: To estimate the standing biomass in prosopis colonised areas of Garissa and Tana River districts by weight, and determine the potential of the standing biomass so estimated for sustainable energy production
This activity entailed the destructive sampling of air-dried weight of prosopis in the identified six training sites in Garissa and Tana River. These included dead trees, standing or lying on the ground, which can still be used for fuelwood. The assumption was that there is enough standing prosopis biomass in Garissa and Tana River districts available for fuelwood production to meet the energy needs of the residents of those districts for 20 years.
From the data gained, it has been estimated that the standing prosopis biomass available is enough to cover the energy needs of the current population of the Dadaab refugee complex (160,000 persons) for a period of 17 years. The biomass is also enough to take care of Kenya’s household energy needs for one year.