Abstract:
Assessing potential land and water resources suitable for surface irrigation is essential for
proper planning of their utilization types. The assessment has a great role in satisfying
subsistence requirements, increasing agricultural production and hence reducing poverty.
Despite efforts made by various stakeholders to improve agricultural productivity by
increasing irrigated areas, Tanzania is still facing a daunting task of reaching the one
million hectare target of irrigated area. This indicates that land and water resources are
not presently effectively utilized. This study was initiated with the objective of assessing
the land and water resources suitable for irrigated agriculture along with the extent of
small-scale irrigation in the Wami sub-basin. Geographical Information System (GIS)
based on Multi Criteria Decision Analysis (MCDA) was used along with various spatial
tools including a model builder which was used to create geo-referenced maps of land and
water resources. Ten layers (irrigation suitability factors) were used in the analysis for
identification of potential land suitable for irrigated agriculture. Results indicate that,
based on the suitability factors about 841.39 km 2 (3.11% of the total area), is highly
suitable for surface irrigation, about 18,244.41 km 2 (67.51%), is moderately suitable and
7939.87 km 2 (29.38%), is marginally suitable for surface irrigation. Furthermore, results
shows that the extent of small-scale irrigation is about 1958.87 km 2 . Moreover, results
indicates that, approximately 1958 km 2 of land assumed to represent the extent of small-
scale irrigated areas in Morogoro region including Dakawa and Mvomero in particular.
As such, the exploration of various resources as observed in this study, including land,
soil and water was well demonstrated by the integration of GIS-Based Multi Criteria
Decision Analysis (MCDA), and the weighted overlay technique for land suitability
analysis.
