scholarly journals Drivers, Impacts and Mitigation of Increased Sedimentation in the Hydropower Reservoirs of East Africa

Land ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 638
Author(s):  
Aloyce Amasi ◽  
Maarten Wynants ◽  
William Blake ◽  
Kelvin Mtei
Keyword(s):  
Climate Change ◽  
Land Use ◽  
East Africa ◽  
Deep Understanding ◽  
Scientific Data ◽  
Sediment Budget ◽  
Catchment Scale ◽  
Sediment Budgets ◽  
Selection Of ◽  
Hydropower Reservoirs

Hydropower reservoirs are essential for the climate-neutral development of East Africa. Hydropower production, however, is threatened by human activities that lead to a decrease in water storage capacity of reservoirs. Land use/land cover and climatic changes are driving accelerated soil erosion in semi-arid East Africa, which ultimately increases reservoir sedimentation and decreases energy production. Sediment delivery dynamics at the catchment scale are complex, involving the interaction of multiple factors and processes on different spatial and temporal scales. A lack of understanding of these processes and their interactions may impede the efficiency of sediment mitigation and control strategies. A deep understanding of the processes of erosion and connectivity of the land to river channel, as well as storage of eroded material within hillslopes and floodplains, and sediment accumulation in the reservoirs supports selection of future dam locations and sustainable management of reservoirs. The sediment budget approach can provide such a holistic perspective by accounting for the various sediment sources, transport, sinks, and redistribution when the sediment is routed through that catchment. Constructing sediment budgets is challenging, but the potential for integrating a number of different techniques offers new opportunities to collect the required information. In East Africa, the spatial planning of dams is mainly dominated by political and financial motives, and impacts of land use and climate on the sediment transport dynamics are not adequately considered. Production of sediment budgets under different scenarios of land use and climate change should be an essential step when deciding the location and management strategies for dams. Selection of new hydroelectric reservoir sites must consider long-term scientific data on climate change, and the sediment budget components for sustainable land management planning, hydropower sustainability.

scholarly journals Drought Risk under Climate and Land Use Changes: Implication to Water Resource Availability at Catchment Scale

Water ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1790 ◽  
Author(s):  
Muhammad Afzal ◽  
Ragab Ragab
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Water Resources ◽  
Groundwater Recharge ◽  
Land Use Changes ◽  
Future Climate Change ◽  
Emission Scenarios ◽  
Catchment Scale ◽  
High Emission ◽  
The Impact

Although the climate change projections are produced by global models, studying the impact of climatic change on water resources is commonly investigated at catchment scale where the measurements are taken, and water management decisions are made. For this study, the Frome catchment in the UK was investigated as an example of midland England. The DiCaSM model was applied using the UKCP09 future climate change scenarios. The climate projections indicate that the greatest decrease in groundwater recharge and streamflow was projected under high emission scenarios in the 2080s. Under the medium and high emission scenarios, model results revealed that the frequency and severity of drought events would be the highest. The drought indices, the Reconnaissance Drought Index, RDI, Soil Moisture Deficit, SMD and Wetness Index, WI, predicted an increase in the severity of future drought events under the high emission scenarios. Increasing broadleaf forest area would decrease streamflow and groundwater recharge. Urban expansion could increase surface runoff. Decreasing winter barley and grass and increasing oil seed rape, would increase SMD and slightly decrease river flow. Findings of this study are helpful in the planning and management of the water resources considering the impact of climate and land use changes on variability in the availability of surface and groundwater resources.

scholarly journals From field to stream: Tracing streambed organic carbon origins at a catchment scale

2021 ◽  
Author(s):  
Katy Wiltshire ◽  
Miriam Glendell ◽  
Toby Waine ◽  
Robert Grabowski ◽  
Barry Thornton ◽  
...  
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Organic Carbon ◽  
Soil Loss ◽  
Sediment Fingerprinting ◽  
Catchment Scale ◽  
Erosion Modelling ◽  
River Corridor ◽  
Soil Loss Equation ◽  
Unmixing Model

<p>Quantifying organic carbon (OC) levels and the processes altering them is key in unlocking soils potential as a mediator of climate change through sequestration of atmospheric CO<sub>2</sub>. In areas of high soil erosion increased fluxes of OC across the terrestrial-aquatic interface are likely and understanding these fluxes is crucial in integrating lateral OC fluxes within the carbon cycle. For this study of a small UK catchment, OC mapping and Revised Universal Soil Loss Equation (RUSLE) based erosion modelling provided estimates of proportional soil OC loss coming from each land use. Sediment fingerprinting using <em>n</em>-alkane biomarkers and a Bayesian unmixing model provided a comparison of streambed OC proportions by land use to assess which processes were dominating OC input to streams. Results showed that RUSLE-based soil OC loss proportions exhibited disconnect with sediment fingerprinting OC composition and the river corridor and riparian environment were key zones in regulating terrestrial to aquatic fluxes of OC.</p>

scholarly journals Land use and climate change impacts on the hydrology of the upper Mara River Basin, Kenya: results of a modeling study to support better resource management

2011 ◽  
Vol 15 (7) ◽  
pp. 2245-2258 ◽  
Author(s):  
L. M. Mango ◽  
A. M. Melesse ◽  
M. E. McClain ◽  
D. Gann ◽  
S. G. Setegn
Keyword(s):  
Climate Change ◽  
Land Use ◽  
East Africa ◽  
River Basin ◽  
Management Practices ◽  
Cultural Landscapes ◽  
Dry Season ◽  
Future Climate Change ◽  
Climate Change Scenarios ◽  
Resource Managers

Abstract. Some of the most valued natural and cultural landscapes on Earth lie in river basins that are poorly gauged and have incomplete historical climate and runoff records. The Mara River Basin of East Africa is such a basin. It hosts the internationally renowned Mara-Serengeti landscape as well as a rich mixture of indigenous cultures. The Mara River is the sole source of surface water to the landscape during the dry season and periods of drought. During recent years, the flow of the Mara River has become increasingly erratic, especially in the upper reaches, and resource managers are hampered by a lack of understanding of the relative influence of different sources of flow alteration. Uncertainties about the impacts of future climate change compound the challenges. We applied the Soil Water Assessment Tool (SWAT) to investigate the response of the headwater hydrology of the Mara River to scenarios of continued land use change and projected climate change. Under the data-scarce conditions of the basin, model performance was improved using satellite-based estimated rainfall data, which may also improve the usefulness of runoff models in other parts of East Africa. The results of the analysis indicate that any further conversion of forests to agriculture and grassland in the basin headwaters is likely to reduce dry season flows and increase peak flows, leading to greater water scarcity at critical times of the year and exacerbating erosion on hillslopes. Most climate change projections for the region call for modest and seasonally variable increases in precipitation (5–10 %) accompanied by increases in temperature (2.5–3.5 °C). Simulated runoff responses to climate change scenarios were non-linear and suggest the basin is highly vulnerable under low (−3 %) and high (+25 %) extremes of projected precipitation changes, but under median projections (+7 %) there is little impact on annual water yields or mean discharge. Modest increases in precipitation are partitioned largely to increased evapotranspiration. Overall, model results support the existing efforts of Mara water resource managers to protect headwater forests and indicate that additional emphasis should be placed on improving land management practices that enhance infiltration and aquifer recharge as part of a wider program of climate change adaptation.

Food production risks associated with land use change and climate change in East Africa

2009 ◽  
Vol 6 (34) ◽  
pp. 342003 ◽  
Author(s):  
Nathan Moore ◽  
G Alagarswamy ◽  
B Pijanowski ◽  
P Thornton ◽  
J Olson ◽  
...  
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Land Use Change ◽  
East Africa ◽  
Food Production ◽  
Production Risks

scholarly journals Climate change adaptation in arable land use, and impact on nitrogen load at catchment scale in northern agriculture

2013 ◽  
Vol 22 (3) ◽  
pp. 342-355 ◽  
Author(s):  
Katri Rankinen ◽  
Pirjo Peltonen-Sainio ◽  
Kirsti Granlund ◽  
Hannu Ojanen ◽  
Mikko Laapas ◽  
...  
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Crop Production ◽  
Nutrient Loading ◽  
Arable Land ◽  
System Level ◽  
Adaptation To Climate Change ◽  
Catchment Scale ◽  
Land Use Patterns ◽  
Arable Land Use

Prolongation of the growing season due to a warming climate could represent new opportunities for northern agriculture. Climatic and biotic constraints may challenge future crop production. The objective of this study was to speculate how a range of arable land use patterns, resulting from various policy driven choices, could be introduced into a farming system, and how they would affect the risks associated with nutrient leaching. We found that while adaptation to climate change must include consideration of crop choices, there are conflicts associated with allocations and rotations for various market and policy situations. The expected increase in nutrient loading in the simulations caused by climate change was moderate. The increase can partly be compensated for by changes in farmland use, more in the shorter term than in the longer term to mid-century. In the future, adaptation at cropping system level is potentially an efficient way to manage nutrient load risks.

SOL40: forty years of simulations under a climate and land use change scenario 

2021 ◽  
Author(s):  
Alessandro Ceppi ◽  
Enrico Gambini ◽  
Gabriele Lombardi ◽  
Giovanni Ravazzani ◽  
Marco Mancini
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Land Use Change ◽  
Curve Number ◽  
Change Scenario ◽  
Catchment Scale ◽  
Physically Based ◽  
Anthropogenic Development ◽  
Meteoric Precipitation ◽  
The Impact

<p>Nowadays, one major issue concerns the land-use change due to urban developments that alters the basin response to meteorological events. With less storage capacity and more rapid runoff, urban river basins rise more quickly during storms and have higher peak discharge rates than rural catchments.</p><p>An exemplary case of this situation is the city of Milan and its whole territory that extends towards north that collects meteoric precipitation, through the Seveso, Olona and Lambro (SOL) rivers plus a number of minor tributaries for a total drainage surface of about 1300 km<sup>2</sup>.</p><p>In order to assess the impact of anthropogenic development on urban catchment scale hydrology, a reanalysis of 40 years of simulations has been carried out with the Curve Number (CN) map based on current land use, and compared to simulations with the CN maps derived using past land use.</p><p>A coupled hydro-meteorological system which comprises the physically based rainfall-runoff hydrological model FEST-WB, developed by the Politecnico di Milano and the ERA5-Land hourly dataset from 1981 to present, provided by ECMWF under the framework of Copernicus Climate Change Service Programme has been built.</p><p>The study (named as SOL40) exactly analyses 40-years trends of the main meteorological (air temperature, precipitation, etc.) and hydrological variables (soil moisture, evapotranspiration and runoff) over the SOL area, and try to quantify and separate the impact of land use change from the climate change scenario.</p>

scholarly journals Acid deposition, land-use change and global change: MAGIC 7 model applied to Aber, UK (NITREX project) and Risdalsheia, Norway (RAIN and CLIMEX projects)

1998 ◽  
Vol 2 (4) ◽  
pp. 385-397 ◽  
Author(s):  
R. F. Wright ◽  
B. A. Emmett ◽  
A. Jenkins
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Acid Deposition ◽  
Base Cations ◽  
Nitrogen Addition ◽  
Scale Model ◽  
N Leaching ◽  
Catchment Scale ◽  
Acid Neutralising Capacity ◽  
Potential Tool

Abstract. Nitrogen processes are now included in a new version of MAGIC (version 7), a process-oriented catchment-scale model for simulating runoff chemistry. Net retention of nitrogen (N) is assumed to be controlled by plant uptake and the carbon/nitrogen (C/N) ratio of soil organic matter, the latter as evidenced by empirical data from forest stands in Europe. The ability of this version of MAGIC 7 to simulate and predict inorganic N concentrations in runoff is evaluated by means of data from whole-ecosystem manipulation experiments at Aber, Wales, UK, (nitrogen addition as part of the NITREX project) and Risdalsheia, Norway (exclusion of acid deposition as part of the RAIN project and climate change as part of the CLIMEX project). MAGIC 7 simulated the changes in N leaching satisfactorily as well as changes in base cations and acid neutralising capacity observed at these two sites. MAGIC 7 offers a potential tool for regional assessments and scenario studies of the combined effects of acid deposition, land-use and climate change.

scholarly journals Road building, land use and climate change: prospects for environmental governance in the Amazon

2008 ◽  
Vol 363 (1498) ◽  
pp. 1889-1895 ◽  
Author(s):  
Stephen Perz ◽  
Silvia Brilhante ◽  
Foster Brown ◽  
Marcellus Caldas ◽  
Santos Ikeda ◽  
...  
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Natural Resources ◽  
Environmental Governance ◽  
Forest Cover ◽  
Planning Process ◽  
Hybrid Approach ◽  
Scientific Data ◽  
Amazon Forest ◽  
Road Building

Some coupled land–climate models predict a dieback of Amazon forest during the twenty-first century due to climate change, but human land use in the region has already reduced the forest cover. The causation behind land use is complex, and includes economic, institutional, political and demographic factors. Pre-eminent among these factors is road building, which facilitates human access to natural resources that beget forest fragmentation. While official government road projects have received considerable attention, unofficial road building by interest groups is expanding more rapidly, especially where official roads are being paved, yielding highly fragmented forest mosaics. Effective governance of natural resources in the Amazon requires a combination of state oversight and community participation in a ‘hybrid’ model of governance. The MAP Initiative in the southwestern Amazon provides an example of an innovative hybrid approach to environmental governance. It embodies a polycentric structure that includes government agencies, NGOs, universities and communities in a planning process that links scientific data to public deliberations in order to mitigate the effects of new infrastructure and climate change.

Climate Change and Land Use Change of Rural Households in The Red River Delta, Vietnam

2013 ◽  
pp. 79-94
Author(s):  
Ngoc Luu Bich
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Agricultural Land ◽  
Rural Households ◽  
River Delta ◽  
Red River ◽  
Red River Delta ◽  
Sea Levels ◽  
Main Production ◽  
Farming Households

Climate change (CC) and its impacts on the socio-economy and the development of communities has become an issue causing very special concern. The rise in global temperatures, in sea levels, extreme weather phenomena, and salinization have occurred more and more and have directly influenced the livelihoods of rural households in the Red River Delta – one of the two regions projected to suffer strongly from climate change in Vietnam. For farming households in this region, the major and traditional livelihoods are based on main production materials as agricultural land, or aquacultural water surface Changes in the land use of rural households in the Red River Delta during recent times was influenced strongly by the Renovation policy in agriculture as well as the process of industrialization and modernization in the country. Climate change over the past 5 years (2005-2011) has started influencing household land use with the concrete manifestations being the reduction of the area cultivated and the changing of the purpose of land use.

PETANI KUNINGAN DALAM PUSARAN KONFLIK KELAS

1970 ◽  
Vol 13 (2) ◽  
Author(s):  
Nanang Susanto
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Action Research ◽  
Participatory Action Research ◽  
Soil Nutrients ◽  
Qualitative Approach ◽  
Participatory Action ◽  
Cost Of Production ◽  
Depth Interviews ◽  
Participatory Observation

Penelitian ini menguji teori Marx yang mengatakan bahwa dalam proses kapitalisasi, petani lahan kecil akan tergusur oleh petani lahan besar. Penelitian ini menggunakan pendekatan kualitatif dengan metode Participatory Action Research (PAR). Menggunakan teknik observasi partisipasi di lapangan, studi ini melakukan wawancara mendalam terhadap petani. Analisis data yang digunakan bersifat induktif. Penelitian ini menghasilkan kesimpulan, bahwa teori Marx tidak terjadi di malar Aman. Adapun penyebab menurunnya pertanian disebabkan menurunnya unsur hara tanah, mahalnya biaya produksi, alih fungsi lahan dan perubahan cuaca. Sedangkan strategi petani lahan kecil untuk mempertahankan kehidupan yaitu melakukan pola tanam tumpang sari, melakukan pekerjaan tambahan, dan mengatur keuangan.This study examines Marx's theory which says that in the process of capitalization, small land farmers will be displaced by large land farmers. This study uses a qualitative approach with the method of Participatory Action Research (PAR). Using the techniques of participatory observation in the field, the study conducted in-depth interviews on farmers. Analysis of the data used is inductive. This study led to the conclusion that Marx's theory does not happen in Aman malar. The cause of the decline of agriculture due to declining soil nutrients, the high cost of production, land use and climate change. While the strategies of small land farmers to sustain life is to do the planting patterns of intercropping, do extra work, and manage finances.

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