Urbanization Of Middle Heihe Basin And Its Effect On Surface Water Balance Based On WRF Model

In the past few centuries, the steps of urbanization gradually accelerated all over the world, it is greatly changed global pattern of land use, which directly or indirectly influence the surface and undersurface water balance, whose influence on the terrestrial ecosystems and the global ecological environment cannot be ignored. The effect urban heat island has become a growing concern of the public over the years. An urban heat island is formed when industrial and urban areas are developed leading to a greater production and retention of heat. A large proportion of solar energy that affects rural areas is consumed evaporating water from vegetation and soil. In cities, where there is less vegetation and exposed soil, the majority of the sun’s energy is absorbed by urban structures and asphalt. Hence, during warm daylight hours, less evaporative cooling in cities results in higher surface temperatures than in rural areas. Urbanization is definitely one of the most characteristic global changes of today and of the coming few decades. Whereas the world population grows with almost one billion per decade, around four fifths of this growth is in urban areas. The challenges due to the development of urban centers, especially great urban agglomerations in developing countries in a sustainable way are huge. Water is one of the key figures in this equation. It has many roles, this paper discusses sustainable urban water infrastructure. First, solutions and experiences from the industrialized countries are summarized, and possibilities and difficulties to adapt them to large urban areas are discussed. A particular focus in the affordability issue is taken. Various development indicators and their applicability are discussed. A summary and discussion on technical, economical, financial, and institutional alternatives follows. The12th five-year plan outline clearly that we will put forward China’s urbanization rate at about61.5%, further large-scale rapid urbanization is an inevitable trend of China’s economic and social development. And impermeable layer caused by urbanization area is increased, the underlying surface change through the surface energy balance and other physical processes, which in turn, changing air thermodynamic cycle, affecting the structure and the development of the boundary layer, affectting the weather process and the regional surface water balance. The surface water balance caused by urbanization of middle reaches area of Heihe river is connected with the arid inland river basin water resources evolution, combined with the continental river basin water shortage in Heihe region, congenital shortage of water resources and the use of unreasonable water problems in the Heihe river basin are the key issues in the social and economic development and environmental protection. How to analysis surface water balance accurately in the Heihe middle reaches at different scenarios for the future development of urbanization, specifically, they are coupling law of urbanization and the surface water balance, customizing different scenarios. And do the fact that the urbanization of Heihe river basin is driven by developing situation, a comprehensive simulation prediction is needed which balanced with the surface water and the coupling between the evolution law of urbanization and eventually, it is an effective way to provide technology support for river basin water resources management decisions.This article focus on the historical development of urbanization, and tries to understand the need of the regional water resources management. By using remote sensing and GIS technology, and based on the1988,1995,2000,2005,2008five time phase of middle reaches construction land structure and pattern in the process of urbanization of Heihe river basin, we use landscape pattern index analysis of the landscape characteristics of different scale, selection of proportion type (PLAND), the number of patches(NP), average patch area, plaque area(MPS)coefficient of variation(PSCV), landscape shape index(LSI), spreading and parallel index(IJI), concentratio(AI), such as landscape index to analysis the characteristics of the spatial heterogeneity of the urbanization, and to analysis the historical urbanization characteristics of space-time evolution, strength and direction in the middle reaches of Heihe river basin. Based on the historical period in Heihe middle reaches the space-time evolution of urbanization, using Markov prediction model structure combined with the region "twelfth five-year" planning of land use structure adjustment, we have established two scenarios of Heihe middle reaches urban area from2010to2020at the pixel level to present the macroscopic land use/land cover demand structure, considering grid level of land use type distribution probability and conversion protection rules, as well as the characterization of the historical land use type stability transformation probability rules, the implementation is based on DLS model under different urbanization development situation of regional land use structure change of spatial pattern optimization. The Weather Research and Forecasting (WRF) Model is a next-generation mesoscale numerical weather prediction system designed to serve both atmospheric research and operational forecasting needs. It features two dynamical cores, a data assimilation system, and a software architecture allowing for parallel computation and system extensibility. The model serves a wide range of meteorological applications across scales ranging from meters to thousands of kilometers, WRF allows researchers the ability to produce simulations reflecting either real data (observations, analyses) or idealized atmospheric conditions. WRF provides operational forecasting a flexible and computationally efficient platform, while offering advances in physics, numeric, and data assimilation contributed by the many research community developers. WRF is currently in operational use at NCEP, AFWA, and other centers, and based on the Noah-LSM schema to clarify the WRF model of coupling city urbanization effects on surface water balance mechanism, and the future situation of surface water balance in numerical simulation, this paper analyzes the influence on the regional balance of surface water, in the view of the urbanization process may cause surface water redistribution problem, analysis of different urbanization scenarios with ground surface upward water vapor flux SH2O, surface runoff SFROFF, soil water content QFX, vegetation layer water content CANWAT, the variation of precipitation to reveal the urbanization effect on surface water balance, and in order to understand the current and future water resources decision problems, we put forward scientific and reasonable planning advice to reduce the adverse influence on the ecological environment and urban development which of great significance to the realization of river basin water resources sustainable utilization.