CHARM: A Hydrologic Model for Land Use and Climate Change Studies in China

China is a country, which is rapidly changing and developing. The population is enormous and still increasing and the economy is growing at a rate that is one of the world's fastest. These factors are placing substantial stress on China's natural resources. Already, the best agricultural land is used and cities are expanding on top of some of this fertile land. Cities are growing so fast that improving and increasing electric and water infrastructure cannot keep up with demand. Much of Northern China is already in a situation of severe water stress. In order to understand how the resource stress will affect China's development, knowledge of the currently available resource in any area is necessary. Furthermore, possible changes in the resource availability in the future must be understood. These changes could be natural or anthropogenic ranging from climate change to changing land from pasture to irrigated farmland. If good data is available, the current resource availability is already known for all areas and a model can be used to investigate the impacts of any changes to the system. However, if good data is not available, a model must be used to gain both the current state and the impacts of changes. The latter is the method employed here to assess China's water availability. In this paper, a hydrologic model is developed to assess China's water availability. CHARM, for Climate and Human Activities sensitive Runoff Model, is developed to provide the runoff produced from rainfall throughout China on a 5 km x 5 km grid-cell resolution. The model is calibrated to average annual watershed runoff values. CHARM can then not only supply currently available surface water runoff for entire regions, but can supply runoff and runoff variability inter-annually and intra-annually for any area desired. Furthermore, it can be used to assess the impacts of land use and climate change on water resources. Here, the methodology of CHARM is developed and validated on two watersheds in the Yellow River Basin in China. It is then used to assess the current water resource supply in China. Finally, the strengths and weaknesses in the model and the modeling approach are discussed to assist the modeler in interpreting the results

Scarcity and abundance of land resources: Competing uses and the shrinking land resource base

Widespread hunger and rising global food demands (FAO, 2009) require better use of the world's water, land and ecosystems. For an estimated world population of about 9 billion in 2050, agricultural production has to increase by about 70 percent globally and by 100 percent in developing countries. An enormous effort is required to achieve the implied annual growth of nearly 1.5 percent (Bruinsma, 2009; Fischer, 2009; Godfray et al., 2010). The following policy challenges are of particular concern: Agricultural water withdrawals amount to 70 percent of total anthropogenic water use, and irrigated crops account for 40 percent of the world's total production (FAO, 2003). This makes the agriculture sector of critical social importance, responsible for massive environmental impacts and vulnerable to competition for land and water resources. Land and water uses for food production regularly compete with other ecosystem services. Ignoring such conflicts over resource use and tradeoffs can lead to unsustainable exploitation, environmental degradation and avoidable long-term social costs. Overcoming this limitation requires better understanding and management of competing uses of land, water and ecosystem services. This includes robust expansion of food and bio-energy production, sustaining regulating ecosystem functions, protecting and preserving global gene pools and enhancing terrestrial carbon pools. The prospect of meeting future water demand is limited by the declining possibilities of tapping additional sources of freshwater, and by the decreasing quality of water resources caused by pollution and waste. Freshwater resources are unevenly distributed, and many countries and locations suffer severe water scarcity (MEA, 2005). Climate change is happening, and further global warming in the coming decades seems unavoidable (IPCC, 2007). Food and water provision, land management, and the protection of nature face the immediate need to develop location-specific coping strategies, to use resources differently, to reduce systemic volatility and to safeguard the full range of ecosystem services. The range of land uses for human needs is limited by environmental factors including climate, topography, and soil characteristics. Land use is primarily determined by demographic and socio-economic drivers, cultural practices and political factors, such as land tenure, markets, institutions and agricultural policies. Good quality and availability of land and water resources, together with important socio-economic and institutional factors, is essential for food security. FAO, in collaboration with IIASA, has developed a system that enables rational land-use planning based on an inventory of land resources, and evaluation of biophysical limitations and production potentials. The Agro-Ecological Zones (AEZ) approach is based on robust principles of land evaluation. The current Global AEZ (GAEZ-2009) offers a standardized framework for the characterization of climate, soil and terrain conditions relevant to agricultural production, which can be applied at global to subnational levels

Key Dimension 4: Environmental Waste Security

Asia and the Pacific shows a positive trend in strengthening water security with the number of water insecure countries dropping to 29 from 38 in 2013, according to this latest edition of the Asian Water Development Outlook (AWDO). Despite this progress, enormous challenges in water security remain. Asia is home to half of the world’s poorest people. Water for agriculture continues to consume 80% of water resources. A staggering 1.7 billion people lack access to basic sanitation. With a predicted population of 5.2 billion by 2050 and 22 megacities by 2030, the region’s finite water resources will be under enormous pressure—especially with increasing climate variability. Recent estimates indicate up to 3.4 billion people could be living in water-stressed areas of Asia by 2050. With a Sustainable Development Goal dedicated to water and sanitation for all, AWDO 2016 is a tool to help assess the region’s progress in meeting this ambitious target

Ion counting efficiencies at the IGISOL facility

At the IGISOL-JYFLTRAP facility, fission mass yields can be studied at high precision. Fission fragments from a U target are passing through a Ni foil and entering a gas filled chamber. The collected fragments are guided through a mass separator to a Penning trap where their masses are identified. This simulation work focuses on how different fission fragment properties (mass, charge and energy) affect the stopping efficiency in the gas cell. In addition, different experimental parameters are varied (e. g. U and Ni thickness and He gas pressure) to study their impact on the stopping efficiency. The simulations were performed using the Geant4 package and the SRIM code. The main results suggest a small variation in the stopping efficiency as a function of mass, charge and kinetic energy. It is predicted that heavy fragments are stopped about 9% less efficiently than the light fragments. However it was found that the properties of the U, Ni and the He gas influences this behavior. Hence it could be possible to optimize the efficiency.Comment: 52 pages, 44 figure

Quasiparticle band structure of infinite hydrogen fluoride and hydrogen chloride chains

We study the quasiparticle band structure of isolated, infinite HF and HCl bent (zigzag) chains and examine the effect of the crystal field on the energy levels of the constituent monomers. The chains are one of the simplest but realistic models of the corresponding three-dimensional crystalline solids. To describe the isolated monomers and the chains, we set out from the Hartree-Fock approximation, harnessing the advanced Green's function methods "local molecular orbital algebraic diagrammatic construction" (ADC) scheme and "local crystal orbital ADC" (CO-ADC) in a strict second order approximation, ADC(2,2) and CO-ADC(2,2), respectively, to account for electron correlations. The configuration space of the periodic correlation calculations is found to converge rapidly only requiring nearest-neighbor contributions to be regarded. Although electron correlations cause a pronounced shift of the quasiparticle band structure of the chains with respect to the Hartree-Fock result, the bandwidth essentially remains unaltered in contrast to, e.g., covalently bound compounds.Comment: 11 pages, 6 figures, 6 tables, RevTeX4, corrected typoe

Accuracy assessment of ISI-MIP modelled flows in the Hidukush-Karakoram-Himalayan basins

Large Asian rivers heading in the Hindukush-Karakoram-Himalayan mountains, and whose streamflow includes significant snow-melt and glacier-melt components, may be highly susceptible to climate warming and pattern changes. Millions of people depend on these streamflows for agriculture and power generation. Reliable predictions of future water availability are therefore needed for planning under a changing climate, and depend on the quality of hydro-climatic modelling. ISI-MIP provides global hydrological modelling results, and need validation at regional scale. This study evaluates the accuracy of modelled flows from the hydrological models used in ISI-MIP, in various sub-basins of the Upper Indus Basin (UIB) and for the reference period 1985-1998. The modelled flows are based on six hydrological models, which are: i) H08, ii) VIC, iii) WaterGAP, iv) WBM, v) MPI-HM, vi) PCR-GLOBWB. Of these models, H08 and VIC are energy-based hydrological models, while the others are temperature-based hydrological models. WBM and MPI are not suitable for the UIB, due to significant under-estimation (by 70-90%) of measured flows by their modelled flows. The remaining four models provide consistent, but still significantly under-estimated flows (up to 60% of measured flows) in all sub-basins, except the Kharmong basin. Monthly differences between modelled and measured flows vary between sub-basins, but with noticeable over-estimation in winter-spring months and under-estimation during summer months. Accuracy of the bias-corrected precipitation data sets (based on five GCMs) used in the ISI-MIP hydrological models has been assessed, using a basin-wide water balance assessment method. This method shows that all precipitation data sets significantly under-estimate precipitation in the UIB, particularly in the Karakoram sub-basins. The selected ISI-MIP hydrological models have used precipitation data which are under-estimates, which may be a main reason for under-estimated flows. ISI-MIP hydrological modelling needs to use the best available precipitation data for the UIB, but other input data and calibration parameters also need revision. An important message from this study is that caution must be exercised in selecting precipitation data sets and hydrological models in alpine regions such as the Hindukush-Karakoram-Himalayas