This paper aims to explore the importance of natural disaster risk management to significantly reduce the impacts of disasters in China. Lessons learnt from the Wenchuan earthquake disaster, a catastrophic disaster that rarely occurred in China’s history, have shown that earthquake forecasting or prediction is a misconception in earthquake disaster reduction because it can not greatly help reduce the impacts of disasters. Therefore, it is high time for our country to shift its conception of disaster management from hazard forecasting or prediction to risk management, an effective and efficient way to reduce the impacts of disasters, in terms of the international progresses in disaster management theory and practices. The essential ways and measures to mitigate the seriousness of earthquake disasters in China include improvement of risk analysis and assessment of earthquake disasters, reduction of exposure and vulnerability in high risk areas through structural and non-structural measures, strict implementation of the building code for seismic design to insure the quality of buildings, especially for the critical facilities, establishment of modern systems of earthquake risk transfer, and enhancement of the national and local capacities to cope with disasters.
Wildfire disasters have brought serious impacts on regional ecosystem and global climate system. The researches onf wildfire risk assessment and fire spreading have positive effect on fire prevention. In this paper, the latest research status and trends of fuel type models, approaches of mapping fuel, wildfire spreading models, computer simulation techniques about wildfire spreading, and wildfire risk assessment were reviewed. Firstly, it is concluded that better fuel models should be developed to supply effective data for the research on regional or global fire risk assessment and fire spread, based on remote sensing information and situ data. Secondly, the geo-spatial information technology and computer technology give solutions to massive data calculation of fire simulation, to establish monitoring system and network information system of real-time, dynamic simulation on fire behavior. Thirdly, wildfire risk assessment is conducted based on disaster system theory, subsequent to the evaluation of hazard factors and vulnerability of burned regions by fuel models and spreading models. Fourthly, integrated, practical, multi-dimensional and standardized wildfire spreading model and decision support system as well as a national fire danger rating system, should be developed in China, to provide a scientific basis for wildfire disaster prevention.
Wetland, considered as the natural ecosystem and landscape, has great resource potentiality and environmental function. For a long time, the change of wetland landscape pattern has been affected by human activities, which has changed the existing wetland functions, and exerted influence on wetland environment. This paper, took the capital city of Beijing as a case for the study of wetland areas, and used Markov model to analyze the dynamic change and the trend of evolution. Supported by RS and GIS technology, combining the previous researches and numerous field investigations, this paper used Landsat TM images of 1996, 2001 and 2005 as the information source to analysis the process of dynamic evolution. The results showed that Beijing wetland recources were degraded significantly. The area of wetland dropped from 62869.64 hm2 in 1996 to 31416.31 hm2 in 2005. The patches of wetlands tended to be irregular, and the degree of fragmentation was increasing. The transition probability matrices at two primary states (1996 and 2005) were established. Then, the development and the future tendency of wetland landscape patterns were simulated and forecasted with Markov process. Under the existing human effects, Beijing wetland landscape pattern may achieve a relative stable state, in which natural rivers make up 10.93% and artificial waters account for 99.17%. The findings have provided the basis for the sustainable development and the scientific management of Beijing's wetlands.
The coordination degree of economic development and environmental health (CDEE) is an important issue in the environmental protection and economic sustainable development. CDEE is usually evaluated by comparing the per capita economic index and environmental index. This evaluation method is satisfactory when applied for evaluating the urban CDEE, but it is not suitable to evaluate the rural CDEE, because the economic development is more depend on the environment in rural than that in urban. In fact, the average index reflected is not the actual CDEE, but the potential or possibility of CDEE. A coordination conception model was put forward is this paper, and an index to reflect environmental changes was applied. The CDEE was regarded as a complex of environmental background, economic base, environmental changes and economic development, and its significant representation was environmental changes due to economic development. The CDEE was divided into four levels: uncoordinated, moderate uncoordinated, moderate coordinated, and coordinated. Integrated evaluation index of spatial difference of land development and the annual change linear slope of normalized difference of vegetative index were used to quantify the model index. The CDEE of each county was analyzed in the Tibet Autonomous Region, and the coordinated counties and uncoordinated counties were distinguished.The result reflected the regional differentiation characteristics in environmental protection and economic development in Tibet Autonomous Region more actually. The CDEE is a complicated theme; furthermore, the reasons and patterns of environmental changes both are multifaceted. Thought NDVI reflects environmental change in vegetation coverage, it can not reflect the environmental changes completely. Therefore, it is still necessary to explore other indexes to reflect the environmental changes more actually in CDEE study.
This paper summarized and compared several methods of monitoring lake ice freezing-on and breaking up and ice thickness by multi-spectral and microwave remote sensing data. Finally, we monitored the lake ice in Nam Co by two methods during the winter half year of 2007/2008. Generally, researchers usually take threshold and index methods to monitor lake ice. According to the differences between ice and water, such as their reflectivity, temperature and backward scattering coefficients, the threshold model can distinguish ice and water directly. It has a high precision with an error of less than 5 days. While the index method recognizes ice and water indirectly by calculations based on spectral and polarization characteristics of ice and water. Additionally, researchers use empirical correlations between ice thickness and its reflectivity, polarization, temperature brightness or other properties to invert thickness. Ice thickness recognition is difficult in lake ice monitoring. Active microwave data is more suitable for ice thickness monitoring than multi-spectral data. Data with high time resolution such as thermal infrared and passive microwave data is more suitable for monitoring lake ice with large areas than the data with high spatial resolutions such as visible, near infrared and active microwave data. Based on multi-source remote sensing data, automatic inversion algorithm will be one of the development trends of lake ice monitoring by remote sensing.
Eco-environment damage has becoming one key point that restrict the development in resource-exhausted areas. And at the same time, tourism industry may become one new suitable industry type to these areas. So this paper based on existing research, advanced the idea and strategy of spatial redistribution of ecological tourism development in abandoned coal mine areas. And taking Wangping town in Mentougou District, Beijing as a case study, this paper analyzed the entire distribution and restoration engineering projects for the study area under the guidance from the idea and strategy which this paper offered.
In this paper, the climate change projections in East China made by the climate models in the IPCC-AR4 were assessed by simulation evaluation and uncertainty analysis. By comparing individual simulation of the 21 IPCC AR4 models with the observations and with each other as well, it is demonstrated that the simulation abilities of different models vary widely. Only models of NCAR-CCSM3 and MRI-CGCM2.3.2 have small root mean square errors for both temperature and precipitation simulations in East China. It has been shown that, under the scenario A1B, multi-model ensemble mean can fairly well illustrate the spatial patterns of annual mean temperature and precipitation. Nevertheless, it can hardly reflect local fine structure of the distributions because of their low spatial resolutions. Moreover, there is a significant systematic deviation in multi-model ensemble mean for temperature projection. It underestimates the annual mean temperature by more than 1.6℃, and the difference between simulation and observation exceeds the extent of the uncertainty which is defined by one-fold standard deviation of inter-models’ simulations. The standard deviation of annual precipitation is up to 26.7% of the multi-model ensemble mean. Therefore it would be quite questionable if IPCC-AR4 multi-model ensemble means of temperature and precipitation in East China are directly used as climate change projection.
The Wuyur River Basin, located in the inland semi-arid region, is sensitive to climate change. The streamflow of Wuyur River is an important recharge source of Zhalong Wetland. The study on the streamflow change associated with the future climate change scenarios has a practical significance for the local socio-economic development and eco-environmental protection of Zhalong Wetland. With the distributed hydrological model of SWAT, the streamflow in the Wuyur River Basin was simulated, and the hydrological response to climate change was analyzed. The simulated results showed that the SWAT model could effectively simulate the streamflow change in the Wuyur River Basin. Especially, at the stations with large amounts of streamflow, the efficiency of simulation was satisfactory. The influence of climate change on streamflow was significant. The streamflow in the future climate change scenarios decreased gradually over time, and different hydrological stations had different streamflow change amplitude. Considering the decrease in streamflow, we need to apply a reasonable water resources allocation for the wetlands in the watershed to alleviate the adverse effects.
As ENSO (El Nino-Southern Oscillation) often leads to alteration in atmospheric circulation and further causes climatic variation, exploring the relationship between regional climate changes and ENSO is helpful for understanding the variation in regional hydrology. This study analyzed the relationship between the climate changes in the Jinghe watershed and ENSO through Mann-Kendall, correlation test and wavelet analysis. Results showed that climate tended to be warmer and drier during 1960-2005, and this trend has been more significant since the 1990s. Climate changes in the Jinghe watershed were closely correlated with ENSO. Precipitation was more sensitive to ENSO than temperature. Precipitation was more sensitive to SOI and temperature was more sensitive to SST. The impacts of ENSO warm events on climate changes in the Jinghe watershed were more significant than cold events.
Palaeoflood hydrological studies were carried out at the upper reach gorges of the Weihe River. Palaeoflood slackwater deposits were found at the DJP site in the Tianshui gorges of the mainstream of the river. Analysis of the grain-size distribution indicates that these SWD consist of silts and clayey silts, sourced from the suspended sediment load of the floodwater. The low magnetic susceptibility indicates they are fresh deposits without weathering and pedogenic alteration. Stratigraphic correlation with the SWD discovered downstream at the Guchuanzhen site of the Weihe River shows that these extreme floods occurred between 3200-3000 a BP at the end of the mid-Holocene climatic optimum. The reconstructed peak discharges of the palaeofloods range from 23,460 m3/s to 25,480 m3/s which are much larger than gauged floods. These results were further tested and proved to be reliable with reconstruction of the modern floods at the same reach. This research is of great importance for hydrological engneering and flood mitigation. And it is also very important for the establishment of the relationships between extreme flood events and global climate change.
Based on meteorological data of summer cloud shape and surface air temperature at 26 meteorological stations during 1961-2005 in the Qilian Mts Region and the surrounding areas, using linear regression analysis, correlation analysis and wavelet analysis of the Mexican Hat Function, the temporal variation and spatial distribution of summer Cb cloud arising frequency and the relationship between it and climate warming were analyzed, and the NCEP/NCAR global reanalysis data in the corresponding period were selected to analyze the circulation characteristics of the summer Cb clouds in the Qilian Mts. Region. The results show that: (1) The summer Cb cloud arising frequency in the Qilian Mts. Region is higher than the Hexi Corridor and the Qaidam Basin. (2) The summer air temperature presents an ascending tendency yearly. The tendency became more clearly since the 1990s, and the summer Cb cloud arising frequency obviously decreased, reducing 8% in the Qilian Mts. Region over the recent 45 years. (3) In the time scales of 3 years and 20 years, the summer Cb cloud arising frequency and air temperature presented an opposite changing structure in the Qilian Mts. Region. In the time scale of 10 years of temperature surge, the characteristics of variations are opposite before the early 1980s. With the rise of temperature both presented the same changing cycles. (4) The decadal and interannual variations of summer Cb cloud arising frequency and air temperature had an obvious negative correlationtains in the Qilian Mts. Region. The analysis shows that under the background of climate warming, the summer Cb cloud arising frequency decreased in the Qilian Mts. Region and the Hexi Corridor, but increased in the Qaidam Basin. (5) The Qilian Mts. Region summer Cb cloud arising frequency responded to the abnormal 500 hPa circulation of in the Eurasian areas.
Water repellency (hydrophobicity) is a property of soils which increases local overland flow and causes soil degradation and has been concerned broadly. Important advances in the researches on the temporal and spatial variation of water repellency and its effects on overland flow generation have been achieved since 2000. This review summaries the last decade work on the effects of soil water repellency on surface runoff generation on the base of reviewing the cause, measurement and temporal and spatial variation of soil water repellency. The main effects include: 1) it has the effects of increasing the infiltration rate and surface runoff significantly and changing the pattern of runoff generation; 2) the persistency and the intensity of soil water repellency are the key factors affecting surface runoff generation; 3) the influence of soil water repellency on runoff generation has scale effects. The influence is significant at point and plot scales, while not notable at a lager scale. However, the impacts of soil water repellency on overland flow generation should be further clarified and researched quantitatively. Soil water repellency, as a factor affecting runoff generation, should be considered in the future researches on runoff generation.
Urban land use structure is always one of research cores both in urban plan and urban geography.Reasonable land use structure has been one of the ways to ptomote urban function and land use benefits. This paper reviews the research results of urban land use structure according to urban land use evolution feature, driving mechanism of urban land use evolution, urban land use structure optimization and urban land use structure dynamic simulation. The conclusions show the present reasearch has its own limits in methods and contents. In the future, following works should be conducted. (1) From the view of rational arrangement of urban functional structure, the relations between urban functional structure and urban land use structure should be studied and the general rule of urban land use structure evolution in different industrial phases should be explored; (2) Static models should be changed to dynamic-quantitative models, and a supporting system for decision-making should be established; (3) A theoretical framework for regulating urban land use types and land use structures should be established to provide a theoretical support for urban planning and land use spatial distribution optimization.
Research on grain production capacity in China mostly put emphasis on rigid loss, and neglects elastic loss of grain productivity, especially that from the perspective of farm household land use behavior. At first, the paper elaborates, at different regional scales and temporal levels, the hierarchy of farm household land use and grain production capacity, and the impacts of farm household land use on the elastic loss of grain production capacity. Then, the research progresses in farm household land use, cultivated land intensive use and farmland productivity. We put forward a research framework of grain productivity on the basis of farm household land use and discuss the related study contents and methods. The study on the process, state, and mechanism of farm household land use behavior is the important basis for grain production capacity elastic loss evaluation. We need to explore the spatial and temporal changes of cultivated land intensive use of farm households and the impacts of the difference in intensity on farmland productivity, to analyze the intensity and the difference of elastic loss of grain production capacity at different spatial and temporal scales, and to set up the model of farm household land use-crop growth-the effects on grain production capacity. The researches include the following five aspects: (1) to analyze the mechanism of household land use, (2) to establish a farm household land use decision-making model, (3) to discuss the difference in household land use, (4) to probe into the impacts of farm household land use on grain productivity, (5) to study the change of arable land intensive use and its effects on grain production capacity. Moreover, we need to apply multidisciplinary methods to study on the elastic loss of grain production capacity, such as traditional study method in combination with remote sense information identification, GIS and spatial orientation, and we also need to make some advances in data collection.
Since the 1980s, the geography of manufacturing has undergone a dramatic transformation in the cities of China. Land policy reforms have played an important role in these spatial changes. This article takes Beijing as a study case, and investigates the spatial changes of manufacturing using unpublished plant-level data for 1985 and 2004. Interviews with more than 20 of the firms and with the administrative agencies in the development zones, done between April 2007 and June 2008 in Beijing, seek answers to the following two key questions. What are the main characteristics of the spatial changes of manufacturing in Beijing? How does land policy reform affect the process of the spatial changes? The result shows that Beijing has experienced the process both of industrial decentralization out of the center and of agglomeration in various types of development zones across the city. In this process, land policy reforms have the influence in three aspects: (1) the switch from rent free land-use to paid land-use promotes a more optimal spatial structure of manufacturing; (2) land supply system and land planning give direction to the development of the manufacturing industry; (3) land property reforms and the transition from agricultural land to construction land in rural areas accelerate the process of rural industrialization and the development of industrial parks.
It is argued in the literature that industrialization and the development of tertiary industry are the major driving forces of urbanization. However, little is known about the implications of institutional forces upon urbanization. Hebi city, a mining city in Henan Province, is taken as a study case to investigate a new type of urbanization in China, i.e. local government-oriented urbanization. As a mining city, Hebi is threatened by the coming exhausting of mining resources. Accordingly, a new city has been built-up beside the old area of Hebi. Through intensive interviews as well as an anthropological fieldwork in 2007, it is found that local governments endeavor intentionally to construct the new city to transfer population and sectors from the deteriorated old city. It is disclosed that a branch of institutional strategies including administrative-boundary adjustments, new-office-building constructions and infrastructure optimizations have been successfully implemented by the local governments. The local governments endeavor to re-orient the development trajectory for the accumulation of both population and sectors, i.e. urbanization. The local governments play a decisive role in the urbanization of Hebi. It is indicated that institutional forces will have important impacts upon urbanization in China.
