Impacts of Climate Change, Land Use and Land Cover Changes on Watersheds in the Upper East Region of Ghana (original) (raw)
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Hydro-climatic and land use/cover changes in Nasia catchment of the White Volta basin in Ghana
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Assessment of past and future land use/cover change over Tordzie watershed in Ghana
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Land use land cover (LULC) changes are highly pronounced in African countries, as they are characterized by an agriculture-based economy and a rapidly growing population. Understanding how land use/cover changes (LULCC) influence watershed hydrology will enable local governments and policymakers to formulate and implement effective and appropriate response strategies to minimize the undesirable effects of future land use/cover change or modification and sustain the local socio-economic situation. The hydrological response of the Ethiopia Fincha’a watershed to LULCC that happened during 25 years was investigated, comparing the situation in three reference years: 1994, 2004, and 2018. The information was derived from Landsat sensors, respectively Landsat 5 TM, Landsat 7 ETM, and Landsat 8 OLI/TIRS. The various LULC classes were derived via ArcGIS using a supervised classification system, and the accuracy assessment was done using confusion matrixes. For all the years investigated, the...
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Water resources are among the most sensitive sectors to climate change due to their direct relationship with climate variables. The current study used projected climate datasets under two Representative Concentration Pathways (RCPs), 4.5 and 8.5, from the Coupled Model Intercompersion Project Phase 5 (CMIP5), remote sensing and Soil and Water Assessment Tool (SWAT) to estimate the effect of projected climate change on some hydrological processes. We focus on rainfall, water yield, soil water storage and evapotranspiration in the Densu Rvier Basin (DRB) for the 2050s. After calibration and validation of the SWAT model, there was a strong correlation between the simulated and the observed stream discharge coefficient of determination (R2) of 0.84 and 0.77, and a Nash Sutcliffe Efficiency of 0.76 and 0.70 for calibration and validation, respectively. The results showed an annual mean increase of 2 oC in temperature, 61% in evapotranspiration and 20.1 mm in rainfall amount by the 2050s ...
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The study examined a comparative analysis of climate and land use change patterns of Calabar River Basin, South eastern Nigeria. The study made use of climate data of 1941-1970 and 1971-2014 obtained from the Nigerian Meteorological Agency (NIMET), Calabar. The climatic data documentation of the (NIMET), Calabar Station that span 43 years (1971–2014) of the study area was compared against NIMET’s historical meteorological data maps of Nigeria between 1941-1970 and 1971-2000, otherwise called the base period to ascertain the status of climate change. Similarly, Remote sensing and GIS were applied to ascertain the Land Use Changes / Land Covers (LULC) that have taken place in Calabar river basin overtime (1980 to 2020) respectively, using imageries from different satellites (Landsat), multi-temporal dates (MSS 1980, TM 1990, ETM 2000 and ETM+ 2010) using ArcGIS. The comparison of climatic data revealed a historical sequential rise in temperature, evidenced by late onset and early cessation of the rains. Temperature has risen by 0.14° F (0.08° C) per decade since 1941-2020, and the rate of warming is more than twice that: 0.32° F (0.18° C) per decade. The late onset and early cessation of rains has necessitated the contraction of the length of the rainy season. This has impacted negatively on farming practices in the region. Furthermore, there is also evidence of significant changes in known weather patterns in the region. For example, the little dry season, then commonly August Break has become less significant in the region. Similarly, the analysis has revealed that the environment has become warmer as temperatures have risen considerably and harmattan dust haze has also become more pronounced in recent years. The result of the analysis for LULC provided six major classifications which include urban (built-up), water bodies, forest, farm, grass and bare surfaces. The built-up area and farmland land uses have increased tremendously (3.19% - 20.73%) and (10.20% - 23.79%) respectively; reductions in forest (35.85% - 24.84%), water bodies (8.77% - 5.27%), Grassland (24.68% - 12.67%) and bare land uses (17.31% - 12.69%). Human activities such as deforestation, urbanization and the burning of fuel (in machinery and automobiles) into the atmosphere contribute to climate and land use changes in the region. A consistent and sustained rise in temperature has been recorded in the region. To ameliorate hazards associated with climate and land use changes, the study recommends among others reforestation and creation of forest reserves, improved energy efficiency, shift to renewable resources / cleaner source of energy (solar and wind), reduced deforestation. There should be absolute compliance with international organizations’ action plans that fight global warming e.g. the Montreal Protocol of 1987, the 1979 convention on long-range transboundary air pollution, the Kyoto Protocol of 1997, the clean air act (1990), UNCED (1992), USA (2008) congress etc. Keywords: Climate; Global warming; Rainfall; River basin; Land use; Tropics *Corresponding Author: I. Michael Inko-Tariah, Email: ibiso.inko-tariah@ust.edu.ng
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This study aims to evaluate the impacts of climate and land use change on the hydrology of Gilgel Abbay's watersheds using the Soil and Water Assessment Tool (SWAT). The study analyzed the hydrologic impacts of climate and land use changes in two ways. The first aspect consists of characterizing hydrological changes two historical land use maps (Land Sat_8 1985 and Land Sat_8 2015) were used to represent land use change on the watershed, and historical climate datasets (1986-2012) was used to create SWAT models for Gilgel Abbay watershed. Land use change detection was done using remote sensing techniques and the maps were processed using ERDAS Imagine 14 and Arc GIS 10.1 software. Climate and Land use are two main factors directly influencing the hydrological processes of the watershed. Gilgel Abbay watershed. RCP 4.5 scenarios were used to project the future climate of 2030's, and 2060's. An increase in precipitation from 67.01 mm to 165.03 mm in the 2030's and decr...
International Journal of Engineering Research and Technology (IJERT), 2021
https://www.ijert.org/scenario-based-impacts-of-land-use-and-climate-changes-on-the-hydrology-of-a-forested-catchment-in-ghana-west-africa https://www.ijert.org/research/scenario-based-impacts-of-land-use-and-climate-changes-on-the-hydrology-of-a-forested-catchment-in-ghana-west-africa-IJERTV10IS040140.pdf This study analysed the separate and the combined impacts of climate and land use (LU) changes on hydrology of the Bonsa catchment in Ghana, West Africa, using the Agricultural Catchments Research Unit (ACRU) hydrological model. The study used five Representative Concentration Pathway (RCP) 8.5 climate change scenarios (wet, 25th percentile, 75th percentile, dry and a multi-model median of nine GCMs) from the CMIP5 AR5 models for near (2020-2039) and far (2060-2079) future time slices. Change factors were used to downscale the GCM scenarios to the local scale, using observed climate data for the control period of 1990 to 2009. The land use of 1991 was used to define baseline hydrological conditions and 2011 land use as well as three future land use scenarios (business-as-usual: BAU, economic growth: EG, economic growth with enhanced reforestation: EGR) for two time slices (2030 and 2070) were used. The study showed that under all separate climate change scenarios, overall flows for the major peak (wet) season reduced, but increased for both the dry and the minor peak (wet) seasons, but under combined climate and LU changes, streamflows increased. Under the combined scenarios, streamflow responses due to the different future LU scenarios were not substantially different. Additionally, LU appeared to be the dominant controlling factor in streamflow changes in the Bonsa catchment under a dry climate change, but under a wet climate change, climate controls streamflow changes. The spatial variability of catchment streamflow changes under combined LU and climate changes were greater than the spatial variability of streamflow changes under climate change.
International Journal of Engineering Research and Technology (IJERT), 2013
https://www.ijert.org/landuse-changes-and-their-impacts-on-the-hydrology-of-the-sumampa-catchment-in-mampong-ashanti-ghana https://www.ijert.org/research/landuse-changes-and-their-impacts-on-the-hydrology-of-the-sumampa-catchment-in-mampong-ashanti-ghana-IJERTV2IS80327.pdf The study determined changes in landuse and cover characteristics and their impacts on the hydrology of the Sumampa catchment. Maps used in the study were prepared by the Arc View GIS dataset. Landuses identified in the area were urban, agricultural and forests. The streamflow was partitioned by means of PART and RORA software programmes. Monthly, annual and decadal streamflow data were generated from daily stage data using the stream's rating curve. Annual vigorous regrowth of the vegetation after lumbering, firewood harvesting, agricultural activities and bushfire coupled with increased mean monthly ET a were found to be major reasons for the 12.25% decrease in the annual mean streamflow. Also, 35.22% degraded forest, 110.46% increase in urban area, 139.20% increase in arable land area, 104.09% increase in the area of secondary forest and temperature rise of 1.16% were found to be responsible for the increase in daily mean ET a by 10.2%, and the mean decadal major seasonal flow by 36.32%.