scholarly journals Quantifying the potential impacts of land-use and climate change on hydropower reliability of Muzizi hydropower plant, Uganda

Author(s):  
Hilary Keneth Bahati ◽  
Abraham Ogenrwoth ◽  
Jotham Ivan Sempewo

Abstract Ugandan rivers are being tapped as a resource for the generation of hydropower in addition to other uses. Studies on the reliability of these hydropower plants due to climate and land-use/land cover changes on the hydrology of these rivers are scanty. Therefore, this study aimed to model the impact of the changing climate and land use/cover on hydropower reliability to aid proper planning and management. The hydropower reliability of River Muzizi catchment was determined from its past (1998–2010) and midcentury (2042–2070) discharge at 75 and 90% exceedance probability under Representative Concentration Pathways (RCPs) of 4.5 and 8.5, respectively. The past and projected hydropower were compared to determine how future climate and land-use changes will impact the discharge and hydropower reliability of River Muzizi catchment. Six LULC scenarios (deforestation, 31–20%; grassland, 19–3%; cropland, 50–77%; water bodies, 0.02–0.01%; settlement, 0.23–0.37%, and Barren land 0.055–0.046% between 2014 and 2060) and three downscaled Regional Climate Model (REMO and RCA4 for precipitation and RACMO22T for temperature from pool of four CORDEX (Coordinated Regional Climate Downscaling Experiment) Africa RCMs) were examined. A calibrated SWAT simulation model was applied for the midcentury (2041–2060) period, and a potential change in hydropower energy in reference to mean daily flow (designflow ≥ 30% exceedance probability), firm flow (flow ≥ 95% exceedance probability), and mean annual flow was evaluated under the condition of altered runoff under RCP4.5 and RCP8.5 climate change scenarios for an average of REMO and RCA4 RCM. The future land use (2048) was projected using the MOLUSCE (Module for Land Use Change Evaluation) plugin in QGIS using CA-ANN. Three scenarios have been described in this study, including LULC change, climate change, and combined (climate and LULC change). The results suggest that there will be a significant increase in hydropower generation capacity (from 386.27 and 488.1 GWh to 867.82 and 862.53 GWh under RCP4.5 and RCP8.5, respectively, for the combined future effect of climate and land-use/cover changes. Energy utilities need to put in place mechanisms to effectively manage, operate, and maintain the hydropower plant amidst climate and land-use change impacts, to ensure reliability at all times.

2020 ◽  
Vol 51 (5) ◽  
pp. 976-993
Author(s):  
Yuhui Yan ◽  
Baolin Xue ◽  
Yinglan A ◽  
Wenchao Sun ◽  
Hanwen Zhang

Abstract Quantification of runoff change is vital for water resources management, especially in arid or semiarid areas. This study used the Soil and Water Assessment Tool (SWAT) distributed hydrological model to simulate runoff in the upper reaches of the Hailar Basin (NE China) and to analyze quantitatively the impacts of climate change and land-use change on runoff by setting different scenarios. Two periods, i.e., the reference period (before 1988) and the interference period (after 1988), were identified based on long-term runoff datasets. In comparison with the reference period, the contribution rates of both climate change and land-use change to runoff change in the Hailar Basin during the interference period were 83.58% and 16.42%, respectively. The simulation analysis of climate change scenarios with differential precipitation and temperature changes suggested that runoff changes are correlated positively with precipitation change and that the impact of precipitation change on runoff is stronger than that of temperature. Under different economic development scenarios adopted, land use was predicted to have a considerable impact on runoff. The expansion of forests within the basin might induce decreased runoff owing to enhanced evapotranspiration.


2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Xiaowei Yao ◽  
Zhanqi Wang ◽  
Hua Wang

Land-use/land cover change (LUCC) is one of the fundamental causes of global environmental change. In recent years, understanding the regional climate impact of LUCC has become a hot-discussed topic worldwide. Some studies have explored LUCC impact on regional climate in specific cities, provinces, or farming areas. However, the quick-urbanized areas, which are highly influenced by human activities, have the most severe land-use changes in developing countries, and their climatic impact cannot be ignored. This study aims to identify the impact of land-use change coupled with urbanization on regional temperature and precipitation in the metropolitan areas of middle and lower reaches of the Yangtze River in China by means of spatial analysis and numeric methods. Based on the exploration of land-use change and climate change during 1988–2008, the impact of land-use transition from non-built-up area to built-up area on temperature and precipitation was analyzed. The results indicated that the land-use conversion has affected the regional temperature with an increasing effect in the study area, while the influence on precipitation was not so significant. The results can provide useful information for spatial planning policies in consideration of regional climate change.


Hydrology ◽  
2021 ◽  
Vol 8 (1) ◽  
pp. 48
Author(s):  
Paul Kiprotich ◽  
Xianhu Wei ◽  
Zongke Zhang ◽  
Thomas Ngigi ◽  
Fengting Qiu ◽  
...  

The Anthropocene period is characterised by a general demographic shift from rural communities to urban centres that transform the predominantly wild global landscape into mostly cultivated land and cities. In addition to climate change, there are increased uncertainties in the water balance and these feedbacks cannot be modelled accurately due to scarce or incomplete in situ data. In African catchments with limited current and historical climate data, precise modelling of potential runoff regimes is difficult, but a growing number of model applications indicate that useful simulations are feasible. In this study, we used the new generation of soil and water assessment tool (SWAT) dubbed SWAT+ to assess the viability of using high resolution gridded data as an alternative to station observations to investigate surface runoff response to continuous land use change and future climate change. Simultaneously, under two representative concentration pathways (RCP4.5 and RCP8.5), six regional climate models (RCMs) from the Coordinated Regional Climate Downscaling Experiment Program (CORDEX) and their ensemble were evaluated for model skill and systematic biases and the best performing model was selected. The gridded data predicted streamflow accurately with a Nash–Sutcliffe efficiency greater than 0.89 in both calibration and validation phases. The analysis results show that further conversion of grasslands and forests to agriculture and urban areas doubled the runoff depth between 1984 and 2016. Climate projections predict a decline in March–May rainfall and an increase in the October–December season. Mean temperatures are expected to rise by about 1.3–1.5 °C under RCP4.5 and about 2.6–3.5 °C under RCP8.5 by 2100. Compared to the 2010–2016 period, simulated surface runoff response to climate change showed a decline under RCP4.5 and an increase under RCP8.5. In contrast, the combine effects of land use change and climate change simulated a steady increase in surface runoff under both scenarios. This suggests that the land use influence on the surface runoff response is more significant than that of climate change. The study results highlight the reliability of gridded data as an alternative to instrumental measurements in limited or missing data cases. More weight should be given to improving land management practices to counter the imminent increase in the surface runoff to avoid an increase in non-point source pollution, erosion, and flooding in the urban watersheds.


2021 ◽  
Vol 21 (3) ◽  
Author(s):  
Susanne Rolinski ◽  
Alexander V. Prishchepov ◽  
Georg Guggenberger ◽  
Norbert Bischoff ◽  
Irina Kurganova ◽  
...  

AbstractChanges in land use and climate are the main drivers of change in soil organic matter contents. We investigated the impact of the largest policy-induced land conversion to arable land, the Virgin Lands Campaign (VLC), from 1954 to 1963, of the massive cropland abandonment after 1990 and of climate change on soil organic carbon (SOC) stocks in steppes of Russia and Kazakhstan. We simulated carbon budgets from the pre-VLC period (1900) until 2100 using a dynamic vegetation model to assess the impacts of observed land-use change as well as future climate and land-use change scenarios. The simulations suggest for the entire VLC region (266 million hectares) that the historic cropland expansion resulted in emissions of 1.6⋅ 1015 g (= 1.6 Pg) carbon between 1950 and 1965 compared to 0.6 Pg in a scenario without the expansion. From 1990 to 2100, climate change alone is projected to cause emissions of about 1.8 (± 1.1) Pg carbon. Hypothetical recultivation of the cropland that has been abandoned after the fall of the Soviet Union until 2050 may cause emissions of 3.5 (± 0.9) Pg carbon until 2100, whereas the abandonment of all cropland until 2050 would lead to sequestration of 1.8 (± 1.2) Pg carbon. For the climate scenarios based on SRES (Special Report on Emission Scenarios) emission pathways, SOC declined only moderately for constant land use but substantially with further cropland expansion. The variation of SOC in response to the climate scenarios was smaller than that in response to the land-use scenarios. This suggests that the effects of land-use change on SOC dynamics may become as relevant as those of future climate change in the Eurasian steppes.


2021 ◽  
Author(s):  
Morteza Akbari ◽  
Ehsan Neamatollahi ◽  
Hadi Memarian ◽  
Mohammad Alizadeh Noughani

Abstract Floods cause great damage to ecosystems and are among the main agents of soil erosion. Given the importance of soils for the functioning of ecosystems and development and improvement of bio-economic conditions, the risk and rate of soil erosion was assessed using the RUSLE model in Iran’s Lorestan province before and after a period of major floods in late 2018 and early 2019. Furthermore, soil erosion was calculated for current and future conditions based on the Global Soil Erosion Modeling Database (GloSEM). The results showed that agricultural development and land use change are the main causes of land degradation in the southern and central parts of the study area. The impact of floods was also significant since our evaluations showed that soil erosion increased from 4.12 t ha-1 yr-1 before the floods to 10.93 t ha-1 yr-1 afterwards. Field surveying using 64 ground control points determined that erodibility varies from 0.17 to 0.49% in the study area. Orchards, farms, rangelands and forests with moderate or low vegetation cover were the most vulnerable land uses to soil erosion. The GloSEM modeling results revealed that climate change is the main cause of change in the rate of soil erosion. Combined land use change-climate change simulation showed that soil erosion will increase considerably in the future under SSP1-RCP2.6, SSP2-RCP4.5, and SSP5-RCP8.5 scenarios. In the study area, both natural factors, i.e. climate change and human factors such as agricultural development, population growth, and overgrazing are the main drivers of soil erosion.


2018 ◽  
Vol 135 (3-4) ◽  
pp. 1031-1044 ◽  
Author(s):  
Thomas Gries ◽  
Margarete Redlin ◽  
Juliette Espinosa Ugarte

2019 ◽  
Vol 11 (24) ◽  
pp. 7083 ◽  
Author(s):  
Kristian Näschen ◽  
Bernd Diekkrüger ◽  
Mariele Evers ◽  
Britta Höllermann ◽  
Stefanie Steinbach ◽  
...  

Many parts of sub-Saharan Africa (SSA) are prone to land use and land cover change (LULCC). In many cases, natural systems are converted into agricultural land to feed the growing population. However, despite climate change being a major focus nowadays, the impacts of these conversions on water resources, which are essential for agricultural production, is still often neglected, jeopardizing the sustainability of the socio-ecological system. This study investigates historic land use/land cover (LULC) patterns as well as potential future LULCC and its effect on water quantities in a complex tropical catchment in Tanzania. It then compares the results using two climate change scenarios. The Land Change Modeler (LCM) is used to analyze and to project LULC patterns until 2030 and the Soil and Water Assessment Tool (SWAT) is utilized to simulate the water balance under various LULC conditions. Results show decreasing low flows by 6–8% for the LULC scenarios, whereas high flows increase by up to 84% for the combined LULC and climate change scenarios. The effect of climate change is stronger compared to the effect of LULCC, but also contains higher uncertainties. The effects of LULCC are more distinct, although crop specific effects show diverging effects on water balance components. This study develops a methodology for quantifying the impact of land use and climate change and therefore contributes to the sustainable management of the investigated catchment, as it shows the impact of environmental change on hydrological extremes (low flow and floods) and determines hot spots, which are critical for environmental development.


2020 ◽  
Author(s):  
Francesca Moschini ◽  
Iacopo Federico Ferrario ◽  
Barbara Hofmann

<p>Quantifying how land-use change affects hydrological components is a challenge in hydrological science. It is not yet clear how changes in land use relate to runoff extremes and why some catchments are more sensitive to land-use change than others. Identifying which areas are hydrologically more sensitive to land-use change can lead to better land-use planning, reduction of the impacts of extreme rainfall events and extended dry periods. In this study we aim to quantify how land-use change and climate change are affecting the hydrological response of  Vietnam’s basins. Over the past decades the country’s land use has shifted from forest to agriculture, with very high production of rice, coffee, tea, pepper and sugar cane.</p><p>We combine the historical, the Intergovernmental Panel on Climate Change’s (IPCC) Representative Concentration Pathway (RCP) RCP4.5 and RCP8.5 climate change scenarios developed for Vietnam, with two different land cover maps (from the years 1992 and 2017). The combined and separate effect of land use and climate change are assessed and the most sensitive to change areas are identified. The Variable infiltration Capacity (VIC) surface water and energy balance model applied here is a grid-based model that calculates evapotranspiration, runoff, base flow, soil moisture and other hydrological fluxes. Surface heterogeneity within VIC is represented by a tiled approach, whereby the surface of each grid-box comprises fractions of the different surface types. For each surface type of the grid-box, the energy and water balances are solved, and a weighted average is calculated from the individual surface fluxes for each grid-box. Hydrological fluxes were compared for each grid cell and basin to analyse the degree of difference between the scenarios.</p><p>Significant changes in future hydrologic fluxes arise under both climate change scenarios pointing towards a severe increase in hydrological extremes. The changes in all the examined hydrological components are greater in the combined land-use and climate change experiments.</p>


Sign in / Sign up

Export Citation Format

Share Document