Understanding of hydro-climatic changes in the world’s river basins is required to ensure future ... more Understanding of hydro-climatic changes in the world’s river basins is required to ensure future food security. Different regional basins experience different levels of hydro-climatic change depending on the endorheic or exorheic nature of a hydrological basin, along with the climatic conditions and human land and water-use practices, for instance for irrigation. This thesis has analyzed long-term hydro-climatic changes in two main irrigated regions of the world: the Mahanadi River Basin in India and the Aral region in Central Asia. Thesis applies a basin-wise, data-driven water balance-constrained approach to quantifying the hydro-climatic changes, and to distinguish their main drivers in the past century and for future. Results point at human water-use and re-distribution for irrigation within a basin as a major driver of water balance changes, which also affect surface temperature in the region.Cross-regional comparison focused on the climatically important changes of water, vapor and latent heat fluxes at the land surface, and also on the changes to water resource availability in the landscape. Results show that irrigation- driven changes in evapotranspiration, latent heat fluxes and associated temperature changes at land surface may be greater in regions with small relative irrigation impacts on water availability in the landscape than in regions with severe such impacts. This implies that one cannot from the knowledge about only one aspect of hydro-climatic change simply extrapolate the impact importance of those changes for other types of water changes in a region.Climate model projections results show lack of consistency in individual GCM performance with regard to temperature and to precipitation, implying difficulties to identify well-performing GCMs with regard to both of these variables in a region. In Aral region, the thesis shows that ensemble mean of different GCM outputs may provide robust projection of future hydro-climate changes.
Achieving universal access to basic services and safe and affordable water and sanitation to all ... more Achieving universal access to basic services and safe and affordable water and sanitation to all by 2030, as targeted in Sustainable Development Goals 1 and 6, is of utmost importance in improving people’s well-being. In Kenya, this means fulfilling a significant water services gap. This study analyzed the viability of user-owned urban water utilities there from managers’ perspectives. It found that the high performance of the few licensed private utilities, high ownership and control, small size, robust public participation, and regulatory policies favor their performance. Yet, the costliness of water services production limits their viability in the most sidelined low-income areas. The article recommends (i) diversifying service production models, (ii) establishing a revolving fund to finance major capital investments, (iii) making full cost recovery a key policy objective, (iv) mobilizing financing from local users, including low-income earners, and (v) setting pricing structures...
African Handbook of Climate Change Adaptation, 2021
Water is the medium through which society experiences the most dramatic and direct manifestations... more Water is the medium through which society experiences the most dramatic and direct manifestations of climate change. At the same time, water has a critical role to play in climate change adaptation and is central towards achieving Africa Water Vision 2025, and the targets set for the 2030 Agenda for Sustainable Development as well as the Kenya Vision 2030. There are fundamental challenges that need to be addressed in order to achieve sustainable water resources management, mainly, the inherent uncertainty associated with the changing climate, the inflexibility in infrastructure and institutions that manage water, and the poor integration of all stakeholders and sectors in water resources management. This study investigates the challenges and opportunities in implementing integrated water resources management and its critical role towards climate change adaptation. A preliminary assessment of sustainable management of water resources and its role in effective climate change adaptatio...
Water on land undergoes and participates in many biogeochemical exchanges and changes. A bits-and... more Water on land undergoes and participates in many biogeochemical exchanges and changes. A bits-and-pieces approach to these may miss essential aspects of change propagation and transformation by lan ...
The multimodel ensemble of the Coupled Model Intercomparison Project, Phase 5 (CMIP5) synthesizes... more The multimodel ensemble of the Coupled Model Intercomparison Project, Phase 5 (CMIP5) synthesizes the latest research in global climate modeling. The freshwater system on land, particularly runoff, has so far been of relatively low priority in global climate models, despite the societal and ecosystem importance of freshwater changes, and the science and policy needs for such model output on drainage basin scales. Here we investigate the implications of CMIP5 multimodel ensemble output data for the freshwater system across a set of drainage basins in the Northern Hemisphere. Results of individual models vary widely, with even ensemble mean results differing greatly from observations and implying unrealistic long‐term systematic changes in water storage and level within entire basins. The CMIP5 projections of basin‐scale freshwater fluxes differ considerably more from observations and among models for the warm temperate study basins than for the Arctic and cold temperate study basins....
Understanding of hydro-climatic changes in the world’s river basins is required to ensure future ... more Understanding of hydro-climatic changes in the world’s river basins is required to ensure future food security. Different regional basins experience different levels of hydro-climatic change depending on the endorheic or exorheic nature of a hydrological basin, along with the climatic conditions and human land and water-use practices, for instance for irrigation. This thesis has analyzed long-term hydro-climatic changes in two main irrigated regions of the world: the Mahanadi River Basin in India and the Aral region in Central Asia. Thesis applies a basin-wise, data-driven water balance-constrained approach to quantifying the hydro-climatic changes, and to distinguish their main drivers in the past century and for future. Results point at human water-use and re-distribution for irrigation within a basin as a major driver of water balance changes, which also affect surface temperature in the region.Cross-regional comparison focused on the climatically important changes of water, vapor and latent heat fluxes at the land surface, and also on the changes to water resource availability in the landscape. Results show that irrigation- driven changes in evapotranspiration, latent heat fluxes and associated temperature changes at land surface may be greater in regions with small relative irrigation impacts on water availability in the landscape than in regions with severe such impacts. This implies that one cannot from the knowledge about only one aspect of hydro-climatic change simply extrapolate the impact importance of those changes for other types of water changes in a region.Climate model projections results show lack of consistency in individual GCM performance with regard to temperature and to precipitation, implying difficulties to identify well-performing GCMs with regard to both of these variables in a region. In Aral region, the thesis shows that ensemble mean of different GCM outputs may provide robust projection of future hydro-climate changes.
Achieving universal access to basic services and safe and affordable water and sanitation to all ... more Achieving universal access to basic services and safe and affordable water and sanitation to all by 2030, as targeted in Sustainable Development Goals 1 and 6, is of utmost importance in improving people’s well-being. In Kenya, this means fulfilling a significant water services gap. This study analyzed the viability of user-owned urban water utilities there from managers’ perspectives. It found that the high performance of the few licensed private utilities, high ownership and control, small size, robust public participation, and regulatory policies favor their performance. Yet, the costliness of water services production limits their viability in the most sidelined low-income areas. The article recommends (i) diversifying service production models, (ii) establishing a revolving fund to finance major capital investments, (iii) making full cost recovery a key policy objective, (iv) mobilizing financing from local users, including low-income earners, and (v) setting pricing structures...
African Handbook of Climate Change Adaptation, 2021
Water is the medium through which society experiences the most dramatic and direct manifestations... more Water is the medium through which society experiences the most dramatic and direct manifestations of climate change. At the same time, water has a critical role to play in climate change adaptation and is central towards achieving Africa Water Vision 2025, and the targets set for the 2030 Agenda for Sustainable Development as well as the Kenya Vision 2030. There are fundamental challenges that need to be addressed in order to achieve sustainable water resources management, mainly, the inherent uncertainty associated with the changing climate, the inflexibility in infrastructure and institutions that manage water, and the poor integration of all stakeholders and sectors in water resources management. This study investigates the challenges and opportunities in implementing integrated water resources management and its critical role towards climate change adaptation. A preliminary assessment of sustainable management of water resources and its role in effective climate change adaptatio...
Water on land undergoes and participates in many biogeochemical exchanges and changes. A bits-and... more Water on land undergoes and participates in many biogeochemical exchanges and changes. A bits-and-pieces approach to these may miss essential aspects of change propagation and transformation by lan ...
The multimodel ensemble of the Coupled Model Intercomparison Project, Phase 5 (CMIP5) synthesizes... more The multimodel ensemble of the Coupled Model Intercomparison Project, Phase 5 (CMIP5) synthesizes the latest research in global climate modeling. The freshwater system on land, particularly runoff, has so far been of relatively low priority in global climate models, despite the societal and ecosystem importance of freshwater changes, and the science and policy needs for such model output on drainage basin scales. Here we investigate the implications of CMIP5 multimodel ensemble output data for the freshwater system across a set of drainage basins in the Northern Hemisphere. Results of individual models vary widely, with even ensemble mean results differing greatly from observations and implying unrealistic long‐term systematic changes in water storage and level within entire basins. The CMIP5 projections of basin‐scale freshwater fluxes differ considerably more from observations and among models for the warm temperate study basins than for the Arctic and cold temperate study basins....
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