Assessing potential land and surface water resources available and suitable for irrigated agriculture in the wami sub-basin Morogoro

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.