The Economics of Climate Change Adaptation and Water Resources: An Application to Dams

Dam construction has increased rapidly since the 1950’s, especially in developing countries. Climate change is likely to impact the demand for new dams as well as future water and sediment inflow in rivers, thereby influencing the utility, management, and lifetime of dams. Proper construction of dams and sediment management can also help reduce the cost and mitigate the risks dams might be facing as a result of changing climate patterns, which will allow communities to utilize water resources more efficiently and sustainably. This dissertation develops a series of dynamic optimization models to determine how the size of different type of dams and their management strategies can help achieve the above goals. First, a single purpose dam’s optimization problem is explored to arrive at desirable results for maximization of net economics benefits with respect to initial reservoir capacity, sediment removal amount, and decommissioning time. Application of this model to Sambor dam in the lower Mekong River basin shows that allowing for optimal reservoir capacity and sediment removal choice has a significant impact on dam life and total net present value, in the absence of climate change considerations. However, both the desirable reservoir capacity and total net present value vary considerably with climate change. Second, management of multi purpose dams under climate change is discussed with respect to determination of optimal reservoir capacity and sediment removal. These two factors generally increase in magnitude as the functions of a dam and its potential benefits increase. Third, optimal reservoir design and systematic management of cascading dams under climate change are studied for coordinated and non-coordinated cases to arrive at the best policy solution. In the application considered, a coordinated strategy between two dams (Luang Prabang Dam and Xayaburi Dam) is beneficial for the entire system, though the difference between the total net present values from the two types of strategies is relatively small. Generally, coordination resulted in the upstream dam requiring a larger reservoir capacity and accumulating more of incoming sediment in order to ease the negative externality to the downstream dam. Finally, the possibility of dam failure is also incorporated in the model of a single dam based on expected annual peak flood flow trends. An innovation in this regard is the determination of an optimally sized spillway to protect against flood overtopping. Three categories of peak flood flow trends are considered to reflect alternate climate change scenarios. With the risk of dam failure involved, the optimal choice of reservoir capacity and spillway capacity are significantly impacted by water availability and the amount of incoming sediment as influenced by climate factors

Hydrolink 2017/4. Multi Reservoir Systems Operations

Topic: Multi Reservoir Systems Operation

Discharge Forecasting By Applying Artificial Neural Networks At The Jinsha River Basin, China

Flood prediction methods play an important role in providing early warnings to government offices. The ability to predict future river flows helps people anticipate and plan for upcoming flooding, preventing deaths and decreasing property destruction. Different hydrological models supporting these predictions have different characteristics, driven by available data and the research area. This study applied three different types of Artificial Neural Networks (ANN) and an autoregressive model to study the Jinsha river basin (JRB), in the upper part of the Yangtze River in China. The three ANN techniques include feedforward back propagation neural networks (FFBPNN), generalized regression neural networks (GRNN), and the radial basis function neural networks (RBFNN). Artificial Neural Networks (ANN) has shown Great deal of accuracy as compared to statistical autoregressive (AR) model because statistical model cannot able to simulate the non-linear pattern. The results varied across the cases used in the study; based on available data and the study area, FFBPNN showed the best applicability, compared to other techniques

Technological Innovations and Advances in Hydropower Engineering

It has been more than 140 years since water was used to generate electricity. Especially since the 1970s, with the advancement of science and technology, new technologies, new processes, and new materials have been widely used in hydropower construction. Engineering equipment and technology, as well as cascade development, have become increasingly mature, making possible the construction of many high dams and large reservoirs in the world. However, with the passage of time, hydropower infrastructure such as reservoirs, dams, and power stations built in large numbers in the past are aging. This, coupled with singular use of hydropower, limits the development of hydropower in the future. This book reports the achievements in hydropower construction and the efforts of sustainable hydropower development made by various countries around the globe. These existing innovative studies and applications stimulate new ideas for the renewal of hydropower infrastructure and the further improvement of hydropower development and utilization efficiency

Effects of Roughness Length Parameterizations on Regional-Scale Land Surface Modeling of Alpine Grasslands in the Yangtze River Basin

Abstract Current land surface models (LSMs) tend to largely underestimate the daytime land surface temperature for high-altitude regions. This is partly because of underestimation of heat transfer resistance, which may be resolved through adequate parameterization of roughness lengths for momentum and heat transfer. In this paper, the regional-scale effects of the roughness length parameterizations for alpine grasslands are addressed and the performance of the Noah LSM using the updated roughness lengths compared to the original ones is assessed. The simulations were verified with various satellite products and validated with ground-based observations. More specifically, four experimental setups were designed using two roughness length schemes with two different parameterizations of (original and updated). These experiments were conducted in the source region of the Yangtze River during the period 2005–10 using the Noah LSM. The results show that the updated parameterizations of roughness lengths reduce the mean biases of the simulated daytime in spring, autumn, and winter by up to 2.7 K, whereas larger warm biases are produced in summer. Moreover, model efficiency coefficients (Nash–Sutcliffe) of the monthly runoff results are improved by up to 26.3% when using the updated roughness parameterizations. In addition, the spatial effects of the roughness length parameterizations on the simulations are discussed. This study stresses the importance of proper parameterizations of and for LSMs and highlights the need for regional adaptation of the and values.</jats:p

Hydropower Development in China: A Leapfrog Development Secured by Technological Progress of Dam Construction

It has been over 110 years since China’s first hydropower station, Shilongba Hydropower Station, was built in 1910. With the support of advanced dam construction technology, the Chinese installed capacity keeps rising rapid growth, hitting around 356 GW nationwide by the end of 2019, and the annual electricity production exceeds 10,000 TWh. At present, China contributes to 25% of global installed hydropower capacity, ranking first in the world for 20 consecutive years since 2001 and surpassing the combined of the 4 countries ranking second to fifth. This paper reviews China’s progress in the context of global hydropower development and examines the role of technological advance in supporting China’s hydropower projects, especially dam construction technology. China is currently actively promoting the “integration of wind, solar, hydro, and coal power generation and energy storage” and building a smart grid of multi-energy complementary power generation. New technologies and new concepts are expected to continue to lead the world’s hydropower development trends

Reservoir delineation and cumulative impacts assessment in large river basins: A case study of the Yangtze River Basin

Ph.DDOCTOR OF PHILOSOPH

Comparative Study and Simulation of Soil Infiltration Performance in Open Green Space

Soil infiltration is important for urban open space to exert sponge benefits, and its permeability characteristics are influenced by physical and chemical properties. To determine the characteristics and differences of soil permeability in different open spaces, we used the cutting-ring method to measure the soil infiltration process in four types of open space. The effects of physicochemical properties on soil infiltration were analyzed through comparison. The infiltration process of the four types of green spaces was fitted on the basis of Kostiakov and Philip infiltration models, and the suitability of the models was discussed. The water infiltration process shows that the law of initial infiltration rate > average infiltration rate > stable infiltration rate. The stable infiltration rate of each green space ranges from 2.46 mm/min to 3.60 mm/min, and the ranking is as follows: park > square > block > other shared space. The determination coefficient of the Kostiakov model for the soil infiltration process of the four types of green space is higher than 0.94, which is suitable to describe the soil infiltration characteristics of green space in the study area. The soil infiltration performance of green space shows a negative correlation with soil bulk density and moisture content but a positive correlation with non-capillary porosity. This study provides a reference for the construction of sponge cities and ecological hydrological observation

Soil erosion and sediment yield in the upper Yangtze, China

Soil erosion and sedimentation are key environmental problems in the Upper Yangtze because of the ongoing Three Gorges Project (TGP), the largest hydro-power project in the world. There is growing concern about the rapid increase of soil erosion over the last few decades and its consequence for potential sedimentation in the reservoir. The study aims to examine controls on the spatial and temporal distributions of sediment transfer within the Upper Yangtze and the hydrological consequences of land use changes, using varied approaches at different catchment scales. First, soil erosion and sedimentation are examined using the radionuclide Cs-137 as a tracer within a small reservoir catchment in the Three Gorges Area. The results indicates that soil erosion on sloping arable land and the rates of reservoir sedimentation have been severe during the past 40 years, mainly due to cultivation on steep slopes. Changes in reservoir sedimentation rates are mainly attributed to land use changes. The suitability of the Cs-137 techniques for investigating soil erosion and sedimentation in intensely cultivated subtropical environments is also considered. The use of the technique for erosion investigation may have limitations due to the abundance of coarse soil textures, uncertainty about fallout deposition rates and the high incidence of human disturbance, but the technique shows promising perspectives for sedimentation investigation since a few dating horizons might be identified. Second, sediment and runoff measurement data for around 30 years from over 250 hydrological stations within the Upper Yangtze have been examined within a GIS framework. The dataset has been integrated with catchment characteristics derived from a variety of environmental datasets and manipulated with Arc/Info GIS. The analysis of the sediment load data has permitted identification of the most important locations of sediment sources, the shifting pattern of source areas in relation to land use change and sub-catchments exhibiting trending sediment yields corrected for hydrological variability. The study demonstrates the importance of scale dependency of sediment yield in both the identification of temporal change and the modelling of relationships between sediment yield and environmental variables, suggesting that the treatment of the scale problem is crucial for temporal-spatial studies of sediment yield