MODELING OF MACRO-CATCHMENT RAINWATER HARVESTING IN SEMI-ARID AREAS

This study contributes to two research themes. First, the study is directed to the theme of effective management of scarce rainwater in semi arid areas of Tanzania and elsewhere. This theme is important because of climate variability and dominance of rain-fed agriculture in semi arid areas. Smallholders who live in tropical semi-arid areas, such as those in Tanzania, have to cope with the realities of living in a dry place with unreliable rainfall, leading to negative impacts on livelihoods. The second theme is modeling of rainwater harvesting systems designed to deal with the problem of rainfall variability. The main contribution of this theme is the rigorous and biophysical modeling approach to designing water harvesting systems for crop. Among models developed PARCHED THIRST model was designed to simulate micro catchments RWH systems. However, after including component for handling runoff routing and rainfall variability in macro catchments now the model simulates macro catchments RWH systems