1.3 Hypotheses
The main hypothesis assumed is the following: Land and water use
activities have negative influence on the water quality of small man made
reservoirs in Zimbabwe.
The following sub-hypotheses are derived from the main hypothesis
and are:
1. Reservoirs located in National Parks and communal lands
exhibit
differences in physical and chemical characteristics resulting
from land use
practices (these differences include a more turbid and nutrient
rich water
column on communal lands and a less turbid and nutrient rich
water column in National Parks).
2. Differences in the physical and chemical characteristics of
reservoirs between communal lands and National Parks result in ecological
differences in plankton communities (plankton found in reservoirs on communal
lands is expected to be more abundant but less diverse, while plankton in
reservoirs in National Parks should be more diverse).
3. There are no seasonal changes in the plankton community
structure of the small reservoirs.
1.4 Objectives
The main objective of this study is to investigate the impacts
of land and water use activities on the water quality of small man-made
reservoirs. This will be achieved by studying the plankton community structure
as an indirect assessment of the water quality. Therefore, the present study
focuses on the following specific objectives:
1. To identify the major water uses and the activities (land
uses) in the surrounding areas of small reservoirs;
2. To assess some aspects of water quality of small reservoirs
and relate them to land and water uses;
3. To identify the plankton (zooplankton and phytoplankton)
in selected small reservoirs and estimate their abundance and diversity in
relation to land and water use;
4. To make a comparison of the plankton community structure
in the selected small reservoirs located in the Matopos National Park and in
communal land areas and relate to land and water use.
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