After analyzing the situation of international negotiation on climate change and the pressure of reducing CO2 emissions China is faced with, the paper puts forward eight countermeasures to cope with the increasing pressure, integrating national development plans with advancement of science and technology at home and abroad. Of the countermeasures, five internal ones, such as optimizing energy structure, improving energy efficiency, encouraging a nation-wide energy-saving movement, augmenting terrestrial and oceanic sink for CO2, and recognizing production transfer, will reduce a total of 50.73 billion t of CO2 emissions after national development plans are realized. It will be a substantial contribution of China to the international mitigation effort and is also an effective answer to the international pressure. Two external measures, such as participating in scientific debate and bidding for a larger emitting share, will alleviate some international pressure and obtain more time and more space for China. The last one is related to science and technology innovation.
Healthy river is a river whose social functions and natural functions can be balanced or compromised in corresponding periods. The symbols of healthy river should be favorable riverbed, acceptable water quality and favorable river ecosystem, when river's social functions and natural functions perform in a balanced way. The river health indicators should reflect the river's natural function status which includes the riverbed, water quality, river ecosystem and runoff. But, the variety and quantity would be different for different rivers because of different natural features and social background. The quantized indicators should be decided according to the requirement of maintaining river's normal natural functions and the extent whether the social functions and the natural functions could perform in the balanced way, and also the indicators should be adjusted according to the change of the natural features and social background. The key to river health is the abundant and clean flow, as the environmental flows are very important to safeguard the river health. The human activities would hurt the river health which include the over water diversion and over power generation from the river, improper regulation of flood and sediment, and over sewage discharge into the river and excessive change of the environmental flows relating to key species habitat. Taking the Yellow River as a case, this paper also explained the method to identify the river health indicators.
Currently the main assessment indicators for GHG emissions include national indicator, per capita indicator, per GDP indicator, and international trade indicator. Based on the GHG emission data from World Resource Institute (WRI), US Energy Information Administration (EIA), and Carbon Dioxide Information Analysis Center (CDIAC), the results of each indictor are calculated for the world and especially for the eight main industrialized countries of US, UK, Canada, Japan, Germany, France, Italy and Russia (G8 Nations), and the five major developing countries of China, Brazil, India, South Africa and Mexico, and their merits and demerits are analyzed. It points out that all these indicators have some limitations. The indicator of Industrialized Accumulative Emission per Capita (IAEC) is identified to evaluate the industrialized historical accumulative emission per capita of every country. IAEC indicator is an equitable indicator for GHG emission assessment, which reflects the economic achievement of GHG emission enjoyed by the current generations in every country and their commitments. The analysis of IAEC indicates that the historical accumulative emissions per capita in industrialized countries such as UK and USA were typically higher than those in the world average level and the developing countries. Emission indicator per capita per unit GDP, consumptive emission indicator and survival emission indicator are also put forward and discussed in the paper.
This study was to examine the effects of main vegetation types on soil moisture and its interannual variations. Soil moisture in 0-10 m deep profiles of six vegetation types, i.e., crop, grass, planted shrub of caragana, planted forests of arborvitae, pine and the mixture of pine and arborvitae were measured in 2001, 2005 and 2006. Soil moisture in about 0-3 m of cropland and about 0-2 m of other vegetation types varied interannually dependent on annual precipitation, but was rather stable interannually below this depth under all six vegetation types. In 0-2 m, soil moisture of cropland was significantly greater than those of all other vegetation types, but there were no significant differences among other vegetation types. In 2-10 m, there was no significant moisture difference between crop and grass, but the soil moisture of both was significantly higher than planted brush and forests. The planted caragana brush and forests had depleted soil moisture below 2 m to or near wilting point, and there were no significant soil moisture differences among different forest types.
Based on the monitoring data of soil salt content, quality of surface water and groundwater in the lower reaches of the Tarim River, the effect of hydrological processes of surface water and groundwater on soil salinization was analyzed. The results showed that there was evident positive correlation between degree of mineralization of surface water and salt content in 0-50 cm soil, but the relationship between degree of mineralization of surface water and salt content in 50-100 cm soil was not evident. Soil salt content was closely related to groundwater depth. And the salt content of 0.50 cm soil decreased with the increase of groundwater depth, especially 0-20 cm soil. The soil salt content was higher and showed a T-shaped distribution pattern when the groundwater depth was lower, but the highly aggregated salt content presented a decreasing trend with the increase of soil depth. On the contrary, the changes of soil salt content showed a diamond-shaped distribution pattern and soil salt content at intermediate layer was higher, when the groundwater depth was higher. The results also showed that the turning point of both groundwater mineralization and soil salt content distribution was 6.0 m. So 6.0 m was the critical groundwater depth to accelerate salt aggregation and stop accumulating soil salt content.
After surveying the Kumtag Desert, the evolution of palaeo-drainage system and its relationship with the formation of desert landform in the Kumtag Desert were studied using survey data, by combining remote sensing images with 1:100,000 scale topographic map and literatures. Some preliminary conclusions were obtained, that is, after the intense uplift of the Altun Mountains in the early Quaternary, a mass of deposition were denuded and conveyed by flood and accumulated on the northern piedmont of the Altun Mountains. The process of accumulation increased not only the depth of the pluvial fan but also lifted its anterior elevation, resulting in eastward deflexion of the palaeo-drainage system, due to lower elevation in the eastern side. After stabilization of the uplift of the Altun Mountains, the flood eroded the pluvial fan, and the gullies, such as Hongliu, Xiaoquan, Suosuo and so on were formed. On the basis of fluviation, the unique desert landscape such as plumed dunes had been formed through intensive wind erosion. The widespread gravel reliefs occurring in desert were constructed by flood events in a relatively short period of time. In addition, the lacustrine sediments appeared at 840 m above sea level reveals that Lop Nur was once connected with Hala lake by Aqik valley. After lake shrinkage, the ancient Shule river and floods from the northern hills gullied the lacustrine sediments from east and north respectively, and two groups of almost vertical Yardang landforms were shaped by wind erosion.
On top of the Shigujian Peak (1477 m asl) of the Dayangshan Mountain in Jinyun County, Zhejiang Province, large amounts of granite pits with diameters ranging from several dozens of centimeters to one meter, and depth from 10 cm to 45 cm are found on the rock surface. These pits mainly appear on the NE and SE sides, and their discharge outlets are in the same direction. The identification results through micropolariscope and X-ray fluroscence spectrometer reveals that the bedrock of pits is from middle to fine-grained moyite being apt to be weathered and mudified. In Dayangshan region the annual mean temperature is 9.2 oC and the annual precipitation at over 1700 mm. On the one hand, there always experiences a period of periglaciation with temperature oscilating near 0 oC for 4 months from December to next March as a consequence, the freezing-thawing cycles may be remarkable to disintegrate the bedrock. On the other hand, the windward slope of Shigujian Peak meets typhoon of over force 10 on the Beaufort Scale in summer, therefore, the blowing makes suspending sands or pebbles grind in swirling form. Based on field investigation and periglaciological geomorphogy, the pits on top of the Shigujian Peak is attributed to frost weathering of periglaciation. Meanwhile, storm and strong wind accelerate the process. Observation shows that both the actions are still undergoing and variant directions of wind aree the main cause for making different shapes of the pits. Because the top of the Shigujian is 1500 m lower than the present snow line, some scholars consider that "glacial pothole" formed in the Quaternary is untenable, even though in the Quaternary Glacial Maximum.
Based on field and geomorphologic investigations, along with analysis of thermoluminescence (TL), magnetostratigraphy and loess-paleosol sequence on terraces, we found that at least four Yellow River terraces, whose ages are 0.86 Ma, 0.62 Ma, 0.13 Ma and 0.05 Ma, have been developed on west Henan fault-uplift system from Sanmen Gorge to Mengjin reach and but only three Yellow River terraces, whose ages are 1.24 Ma, 0.25 Ma and 0.05 Ma, have been developed on North China fault depression system from Mengjin to Kouma reach. All the terraces have similar structure that they have paleosols with a thickness of several meters developed on top of the fluvial silt. It shows that the Yellow River incised when terraces were abandoned during the transitional period from glacial to interglacial and there may be a link between the formation of terraces and glacial-interglacial climatic cycles. However, the differences in Yellow River terrace sequences between the two tectonic units, i. e., west Henan fault-uplift and North China fault depression, indicate that the land uplift has been playing an important role in the formation of these terraces.
Using NCEP/NCAR reanalysis geopotential height and winds at 500 hPa and 850 hPa, precipitation rate, sea level pressure (SLP), as well as the observed precipitation from more than 600 stations in China in June- August from 1951 to 2006 and focusing on the East Asia -West Pacific region (10o-80oN, 70o-180oE), interannual variation of East Asian summer monsoon (EASM) and the relationship with atmospheric circulation and rainfall are studied by means of statistical diagnose methods, such as 9 points high-pass filter, empirical orthogonal function (EOF) analysis, composite analysis etc. Some conclusions can be drawn as below: (1) From the EOF analysis result of SLP in the East Asia -West Pacific region, a zonal dipole oscillation mode between Mongolia cyclone and West Pacific anticyclone (APD) can be found and the APD index can act as an intensity index of EASM. (2) The EOF-1 of anomalies of geopotential height at 500 hPa show an obvious meridional East Asia remote correlation mode (EAP) and EAP index also can be seen as an intensity index of EASM. (3) The result of composite analysis to the years with high/low APD index reveals that APD index is closely correlated with EAP at 500 hPa/850 hPa. The correlation coefficient between APD index and EAP index is - 0.23, which can pass the significant test at confidence level 0.1. (4) Both APD index and EAP index are closely correlated with rainfall in the flood season in China and precipitation rate in the East Asia -West Pacific region. The significant correlation areas at confidence level 0.05 are mainly located in the scope from the land south of the Yangtze River valley to the sea south to Japan, and the former/latter is positive/negative, respectively.
In the context of haze days during the period 1961-2005 over China, the characteristics and changes of temporal and spatial distribution of haze days as well as possible reason and the relationship with the trend of global solar radiation and sunshine duration are analyzed. Result shows that the spatial pattern of annual and seasonal haze days presents more in eastern and less in western China. There are three regions with the number of haze days coinciding with the economically developed regions: the lower and middle reaches of the Yangtze River, North China and South China. Apart from Northeast China, the Qinghai-Tibet Plateau and western part of Northwest China with small annual variation and less in values, the annual variation of haze days is obvious in most of the other regions. The haze days are maximum in winter and the minimum in summer. In recent 45 years, the national mean annual haze days exhibited obvious increasing trends with the maximum in 2004. In most parts of eastern China, the number of haze days shows increasing trends, particularly in areas such as the middle and lower reaches of the Yangtze River, Pearl River Basin and west of Henan Province with obvious trends and the increments of haze days are great, where the increasing air pollution caused by human activities and climate change are the possible reasons. In western China and Northeast China, the trend is decreasing. In North China, the middle and lower reaches of the Yangtze River and South China, the trends of haze days and sunshine durations are opposite. The increasing haze days may be one of the reasons leading to the decrease of global solar radiations. In Northeast China, Northwest China, Southwest China and Tibet-Qinghai Plateau, the trends of haze days show slight decrease and are identical to the change of sunshine duration. But in these regions the haze seldom occurs and the change of it will not greatly affect the change of sunshine duration and global solar radiation.
In this paper, we selected and used 2038 flood disaster data from 84 counties of Xinjiang in 1950-2006, and adopted the gray relational evaluation model, taking county as a unit, to divide Xinjiang into heavy flood disaster subregion, secondary heavy flood disaster subregion, general flood disaster subregion, light disaster flood subregion and tiny flood subregion. We also adopted autoregression moving average model ARMA(p, q) and second order principal value function to analyze long-term trend of disaster affected area, as well as its oscillation cycle with Morlet wavelet. Results show that the flood affected area throughout the region and every subregion had a changing cycle of 12-15a, the flood frequent oscillation cycle was on interdecadal and interannual scale of climatic background after the 1980s, and the superposition of small oscillation cycle as 7-8a and 2-3a was comparatively frequent. In terms of the flood disaster variation trend of Xinjiang, the outlook is not optimistic for the general flood affected area presented a distinct increasing trend and each flood subregion was in the climatic background with frequent period of flood at present. The distributing trend of flood disaster affected area and the oscillation cycle in the north and south piedmonts of the Tianshan Mountains played a decisive role relating to the interannual long-term trend and its oscillation cycle in the flood affected area in Xinjiang. These regions were the keys in reinforcing facilities and strength for flood prevention and control. Otherwise, the general flood affected area would have a greater impact on the flooded area of entire Xinjiang, leading to an increasing trend in the future regardless of the short, medium or long period changes, hence great attention should be aroused.
