Sun Guangyou

Catastrophic eco-environmental change in the Songnen Plain, northeastern China since 1900s

Although the Songnen Plain in the northeastern China was developed relatively late in the temperate zone of the world, its eco-environment has changed greatly. This paper analyzes the changes of land cover and the rates and trends of desertification during the past 100 years in the Songnen Plain. According to the macroscopic analysis, we find that the eco-environment in the plain has reached to the threshold of catastrophic change since the 1950s. The Thom Needle Catastrophic Model was used to determine and validate this conclusion. Human activities, including large-scale construction projects, such as huge dams and dikes, and excessive grazing were the primary factors contributing to regional eco-environmental catastrophe. And irrational reclamation of the wilderness also affected the eco-environmental change. The results reveal the complex human-land interactions.

IMPACT OF OIL FIELD EXPLOITATION ON ECO-ENVIRONMENT OF THE DAQING LAKES

The Daqing lakes are located in the region with sub-humid continental monsoon climate. Through historical comparison of the environment before and after oil field exploitation in the area, the paper analyses the impact of oil field exploitation on the eco-environment of the lakes, including the impact of diversion works, drainage works, exploitation and utilization of groundwater, dropped crude oil and petrochemical wastewater on the lakes water body. The analysis shows that oil field exploitation caused serious pollution to soil in the lakes area and deterioration of the eco-environment. The impact became more evident with passage of time, and the intensity varied with areas, getting more serious from west to east, which meant that the eastern part of the lakes were influenced much more seriously by the human activities. To improve the eco-environment of the Daqing lakes and make them sustainable utilization, the effective protection measures should be taken.

Concept, distribution law and formation machanism of inland saline-alkaline wetland: Taking Songliao Plain for example

The paper, taking Songliao Plain for example, studied the concept, distribution law and formation mechanism of inland saline-alkaline wetland. The inland saline-alkaline wetland is distributed over the inland region of arid or semi-arid climate; it is the wet or slightly stagnant environment, forming saline-alkaline soil and salt vegetation and making the geogra phical environment fonming complex with an ecosystem of saline-alkaline wetland. The laws of zone nature and non-zone nature control the distribution of the inland saline-alkaline wetland that extensively spreads in north part of China and other countries. The inland saline-alkaline wetland is formed jointly by atmosphere, hydrosphere, lithosphere and biosphere including intellectual sphere. Under the special condition, the artificial activity is possibly the key function. In order to improve the human environment, it is a great duty confronting the whole world to rationally transform the inland saline-alkaline wetland. Therefore, we presented an anti-inland theory to promote the environment transformation.

Content and distribution of trace elements in soils of the dam river and Tuotuo river basins

Natural contents and distribution of trace elements in soils of the Dam River and Tuotuo River basins are demonstrated in this paper. By using contrasting methods, it is found that the content of trace elements of soil in the region is at the lower limit of the world’s soil content level, that the tendency of the average trace element content in the four main types of soil is shown as: alpine mountain meadow soil>marsh soil>alpine mountain steppe soil>alpine mountain cryogenic soil, the average content of trace elements such as Cr, Co, Zn, Cu, Hg, Pb, Mo, Mn and Ni in the Dam River basin is higher than that of the Tuotuo River basin except that of the elements Ba and Sr. In addition, through correlation analysis, the relationship of intergrowth and association among soil elements are revealed.