https://cris.library.msu.ac.zw//handle/11408/153 Tue, 21 Apr 2026 09:49:07 GMT 2026-04-21T09:49:07Z https://cris.library.msu.ac.zw//handle/11408/3250 Title: The effect of resettlement induced land use changes on Mavaire river discharge in Shashe subcatchment Authors: Ndau, Blessing Abstract: Land use changes have been occurring as a result of human uses for developmental purposes. These changes will certainly have a negative influence on the hydrological characteristics of catchments, thereby inducing an increase in surface runoff, soil erosion and sediment inputs. In the year 2000, Rio Tinto discovered kimberlite diamonds in Murowa, Zvishavane. This discovery led to the relocation of 142 families to Shashe resettlement block in Masvingo Province near Mashava. The area which was once rangeland area was then converted to settlement and cultivation in 2004. The land conversion has had significant effects on runoff which results in sedimentation of the Mavaire river. To determine the effect of the resettlement induced land use changes on Mavaire river discharge firstly, the spatial and temporal land use changes that took place in Shashe were determined using landsat images with ArcGIS 10.1 and the results showed that a significant change in the spatial and temporal land uses existed. The major land use changes which took place for the 3 years of 1998, 2006 and 2014 were as follows; Water percent area was decreasing for this time period and it was 1%, 3% and 2% respectively. Mining percent area was also decreasing and was 18%, 12% and 4% respectively. A decrease in forest area was also noted. It was 29%, 22% and 3% respectively. Grassland percent area was 34%, 16% and 12%. Cultivation percent area was 13%, 17% and 32%. Rangeland was 29%, 30% and 47%. Secondly the relationship between the selected land uses and runoff was then tested using linear regression. Further statistical analysis was done with R2 value and standard error. A strong relationship between selected land uses and runoff of Mavaire river was found. A strong positive relationship was y = -0.146x+66713 for mining, the R2 value 0.970 and it had a standard error of 18% .A decrease in forest area resulted in an increase in runoff and a strong positive relationship existed between the two at a slope of y = 0.077x+66669. The R2 value was 52% and its standard error was 0.930. Cultivation area was increasing, this resulted in an increase in runoff at a slope of y = 0.125x+65790. The standard error was 32% and the R2 value of 0.930. Rangeland area was also increasing but it resulted in a decrease in runoff at a slope of y = 0.119x+65433. The R2 value was 0.786 and its standard error was 54%. The results from this research are particularly relevant for Shashe resettlement block in formulating, implementing and monitoring strategies for sustainable development such as farmer training programmes on conservation agriculture, promoting the use of biofuels to reduce deforestration, also monitoring of the cutting down of trees with the help of the Environmental Management Agency and chiefs as well as headmen with the help of the Ministry of Agriculture should designate properly managed paddocks to control overgrazing. The government and eminent domains should also ensure that negative effects of resettlements are given due consideration in the planning procedure to avoid environmental consequences. Also there is need to conduct research on future land use change effects on dam sedimentation of Mavaire river. Thu, 01 Jan 2015 00:00:00 GMT https://cris.library.msu.ac.zw//handle/11408/3250 2015-01-01T00:00:00Z Ndau, Blessing https://cris.library.msu.ac.zw//handle/11408/2610 Title: Water productivity and the relative effects of salinity on crop yields for a surface irrigation scheme – a case of Insukamini Irrigation Scheme Authors: Makwara, Nabars Abstract: Increasing water productivity is generally explained as to either produce similar yield using less water or obtaining more crop yields using the same water resources. Water is becoming scarce due increase in population as well as competition with other non- agricultural demands. At Insukamini Surface Irrigation Scheme, farmers over apply water volumes with the idea that they can increase their yield. However the Scheme has been facing challenges of yield decline from 2009 to 2014. This study was therefore designed to quantify the current levels of water productivity and the relative effects of salinity to crop yield. Questionnaire survey and laboratory experiments were done to assess the crop water productivity, irrigation water and soil quality parameters and their impact on the yield of sugar beans and maize grain. The results indicated that the soil was saline with EC ranging from 0.52dS/m-0.58dS/m. A reduction in the yield over 7 years was noted and there was a low water productivity ranging between 0,37kg/m3 to 0.68kg/m3 for maize and 0.33kg/m3 to 0.62kg/m3 for sugar beans. The conclusion was that the salinity is as a result of salt accumulation from irrigation water, decline in yield is caused by salinity levels, crops being grown are not tolerable to the salinity levels, hence low water productivity. It was recommended that the farmers should grow more salt tolerant crops, correct the salinity, practice deficit irrigation and practice good irrigation management practices. Thu, 01 Jan 2015 00:00:00 GMT https://cris.library.msu.ac.zw//handle/11408/2610 2015-01-01T00:00:00Z Makwara, Nabars https://cris.library.msu.ac.zw//handle/11408/2132 Title: Effects of land use and land cover change on sediment yield for Upper Sebakwe and Upper Nyazvidzi sub-catchments in Chikomba District Authors: Chiwera, Blessing Abstract: The study of the response of sediment yield to land use and land cover changes is quite critical for watershed management and policy formulation. This research investigated the effect of land use and land cover changes to sediment yield from upper Sebakwe and upper Nyazvidzi sub-catchments. Changes in land use and land cover were determined by the use of Landsat Thematic Mapper ™ imagery for years 1984, 1994, 2004 and 2010 using ArcMapTM 10 tool. Sediment yield resulting from the land use and land cover changes was calculated using the Regional Small Catchment Sediment Yield Prediction Model for years 1984, 1994, 2004 and 2010. The effects of changes in land use and land cover to sediment yield were evaluated based on the correlation tested between the parameters. In upper Nyazvidzi sub-catchment, 31.2% of forest area was lost while in upper Sebakwe sub-catchment, there was a loss of 31.3%. Cultivated land increased by 10.9% for upper Nyazvidzi while a slight 0.1% was increased in upper Sebakwe. Pasture land increased by 38.2% and 31% for upper Nyazvidzi and Sebakwe sub-catchments respectively. There was a significant loss of water bodies in upper Nyazvidzi with a reduction by 16.8% while Sebakwe gained by 0.1%. These changes in land use and land cover resulted in significant changes in sediment yield for both sub-catchments. This study proved that land use and land cover changes are usefully correlated to sediment yield in both sub-catchments. These findings are relevant to sub-catchments which are experiencing dynamic land use and land cover changes which often lack measurement. The resultant effects of these changes are of great concern relative to sediment yield which causes siltation of water bodies and loss of watershed integrity in many sub-catchments. Thu, 01 Jan 2015 00:00:00 GMT https://cris.library.msu.ac.zw//handle/11408/2132 2015-01-01T00:00:00Z Chiwera, Blessing