|
GIS and natural resource management : prospect and problems Kanyati Communal Lands, Zimbabwe 
Figure 3. Distance grazing areas and drinking places for livestock in dry season. Availability of water is a problem for local communities. It is clear from Figure 3 that the proposed boreholes in are roughly in proper locations for livestock watering, although they could be spread a bit more. In some villages (central Makande and east Nyadara), the proposed boreholes are not useful at all for livestock watering because watering points already exist at proper locations. Several potential grazing areas will remain too far away from water after construction of the proposed boreholes. Application D. Livestock carrying capacity and current stocking densities This application shows the variation among the villages regarding amount of forage available for livestock and actual stocking densities. The numbers of livestock are expressed in Tropical Livestock Unit Equivalents (LUs1) for this purpose. By comparing the potential LU numbers (carrying capacity) of each village with the actual LU numbers, the LU balance per village was estimated. When the potential LUs are lower than the actual LUs, the village is expected to be overgrazed (Table 4). The total number of livestock (expressed in LUs) was calculated for each village based on (i) actual livestock numbers per species per village in 1992 and (ii) the conversion values shown in footnote 1. Next, the carrying capacity (potential livestock numbers LUs per village) was calculated based on field staff estimates of the carrying capacity of mapping units shown on the available vegetation maps produced by ARDA (Figure 4). Conversion values of livestock species kept in the study area: Cattle: bulls (LU = 0.75); oxen (LU = 0.94); cows (LU = 0.64); steers (LU = 0.61); heifers (LU = 0.55); calves (LU = 0.28) Other: goats (LU = 0.07); sheep (LU = 0.07); donkey (LU = 0.40). |