Land use-land cover change in the Tano basin, Ghana and the implications on sustainable development goals.

The changes in land use and land cover (LULC) contribute to carbon emissions that lead to climate change and global warming. Obtaining information on LULC change is of necessity to ensure land transformation planning, and anthropogenic and natural impact evaluation. The objective of this study is to analyze the historical changes in LULC in the Tano River Basin of Ghana, to provide scientific information for decision-making on achieving sustainable development. A supervised classification of Landsat images (1986, 2010, and 2020) using the Random Forest algorithm was performed, as well as a post-classification comparison of LULC maps in terms of area and size. A "from-to" matrix was used to identify the changes in LULC that occurred between the periods 1986-2010, 2010-2020, and 1986-2020. The results show an overall classification accuracy of 88.9, 88.5, and 88% for LULC maps for the years 1986, 2010, and 2020, respectively. Between the period 1986 and 2020, there is a conversion of the greater part of dense forest to open forest, and subsequently to settlement and cropland as a major historical LULC change pattern in the Tano basin. Cropland and Settlement increased at the rate of 24.8 km/yr and 1.5 km/yr respectively, while Dense forest and Open forest decreased at the rate of 298.4 km/yr and 173.9 km/yr over the period 1986 to 2020. The study outputs are not only useful for formulating and implementing national policies and programs but also, can contribute to assessing and monitoring progress towards attaining Sustainable Development Goal 13 (climate action).

Analyses of crop water use and environmental performance of small private irrigation along the white Volta basin of Northern Ghana.

Small private irrigation (SPI) is a farmer-initiated irrigation which has the potential to increase the contribution of the overall irrigation sector to global food security. However, there is no much information about these systems for effective policies for regulation. This study compared the resource use productivities and environmental impacts of SPI systems to those of a government-led irrigation scheme (GIS) in Northern Ghana. The results showed that land productivity was higher in the SPI than in the GIS. Productivity per unit cultivated area was 2571.00 US$/ha under SPI while that of the GIS was 676.00 US$/ha. Output per unit command area was also two times higher in the SPI than in the GIS; that is 2571.00 US$/ha and 1113.00 US$/ha for SPI and GIS respectively. For water productivity, output per unit irrigation supply was 0.33 US$/m3 and 0.08US$/m3 for SPI and GIS respectively while output per unit water consumed by ET was 0.60 US$/m3 for SPI and 0.06 US$/m3 for the GIS. The results implied that the SPI schemes performed better in land and water productivities compared with the GIS which is attributed to higher yields and the selection of high valued crops by farmers under SPI. However, both irrigation system types at the time of this study did not cause significant deterioration to the water bodies and surrounding environment as the biochemical oxygen demand (BOD) values of nearby water bodies were less than 3.0-5.0 mg/l, which is considered as acceptable levels for drinking water by World Health Organisation (WHO) while salinity levels were also within acceptable limits (<750 µS/cm). With appropriate policies to regulate and provide support systems to the SPI, these systems may increase the overall agricultural productivity and improve job creation for the teeming unemployed youth and women in the savannah agroecological zone of Ghana.