Connotation of urban ecological quality and the construction of its core index system.

Urban ecological quality is a necessary attribute for a healthy urban ecological state. In the period of urban development from large-scale incremental construction to stock improvement and quality transformation and incremental structural adjustment, there are many gaps between urban ecological quality construction and the requirements of the new stage. There is an urgent need to understand and integrate multiple needs, and construct an indicator system to promote the balance between supply and demand of ecological resources and efficient use to enhance urban ecological quality.

Carbon neutral contribution and regional differences of clean energy based on life cycle assessment.

Developing clean energy is an important strategy to achieve global carbon neutrality. In the entire life cycle industrial chain of clean energy systems, fossil energy was directly or indirectly consumed during the processes from raw material production to waste disposal stages. The energy consumed by clean energy construction differed across regions, resulting in various carbon neutrality contributions of clean energy in different regions.

[Spatial distribution characteristics of carbon, nitrogen and phosphorous and pollution status evaluation of sediments in the Haihe River Basin, China.].

Studying the distribution of carbon, nitrogen and phosphorus of sediments on a whole-watershed scale is important to the research and management of water resources in the Haihe River Basin (HRB). In this study, total organic carbon (TOC), total nitrogen (TN), and total phosphorus (TP) of 163 samples were investigated in the HRB. Based on these data, the pollution le-vels of sediments were assessed by using different quantitative indices.

[Review on studies of anthropogenic heat emission.].

With the rapid development of metropolises worldwide, the urban heat island (UHI) effect is becoming a serious environmental problem in recent years. The rapidly increasing anthropogenic heat (AH) from human activities has more significant impacts on urban microclimate which aggravates the UHI effect. The characteristics of AH emissions at different scales may vary according to different natural backgrounds.

[Potential ecological risks assessment of heavy metals in the reservoir sediment of the western Haihe River basin].

The reservoirs distributed in the western part of Haihe River basin play a key role in drinking water supply in the densely populated region. The potential ecological risk of heavy metals stored in the reservoir sediments has drawn more attention during recent decades. In this study, a total of 10 reservoirs in the western Haihe River basin were sampled.

[Impacts of urban cooling effect based on landscape scale: a review].

The urban cooling island (UCI) effect is put forward in comparison with the urban heat island effect, and emphasizes on landscape planning for optimization of function and way of urban thermal environment. In this paper, we summarized current research of the UCI effects of waters, green space, and urban park from the perspective of patch area, landscape index, threshold value, landscape pattern and correlation analyses. Great controversy was found on which of the two factors patch area and shape index has a more significant impact, the quantification of UCI threshold is particularly lacking, and attention was paid too much on the UCI effect of landscape composition but little on that of landscape configuration.

[Ecological risk assessment of heavy metals in surface sediments in the southern and central Haihe River Basin].

Several heavy metals, including Cu, Zn, Cr, Ni, Pb, and Cd, were investigated at 80 sampling sites in the southern and central areas of Haihe River Basin. The spatial patterns and potential anthropogenic impacts of heavy metals were evaluated by several methods, such as the potential ecological risk index and enrichment factors (EFs). Results showed that, (1) The concentrations of heavy metals in the sediments were higher than the background values in most sites except for Cr, Ni.

[Health assessment of river ecosystem in Haihe River Basin, China].

With the development of economy, the health of river ecosystem is severely threatened because of the increasing effects of human activities on river ecosystem. In this paper, the authors assessed the river ecosystem health in aspects of chemical integrity and biological integrity, using the criterion in water quality, nutrient, and benthic macroinvertebrates of 73 samples in Haihe River Basin. The research showed that the health condition of river ecosystem in Haihe River Basin was bad overall since the health situation of 72.

[Regionalization of the freshwater eco-regions in the Haihe River Basin of China].

There is a growing concern about the ecological conditions in the Haihe River which have been profoundly impacted by the growing human population and intensifying development over the past several decades. By identifying the spatial characteristics of terrestrial and fluvial landscapes, we propose the guidelines and criterions for regionalizing the freshwater ecosystems in the Haihe River basin. The first-level and second-level zones reflect the spatial patterns of the natural backgrounds which could impact the surface water quantity and quality.

[Recreational attraction of urban park wetlands in Beijing].

Taking the 20 urban park wetlands in Beijing as test objects, a 3-layer evaluation index system including urban park wetland landscape quality, location condition, and accessibility for the recreational attraction of urban bark wetlands was established, and, by using analytic hierarchy process (AHP) and an integrating index evaluation method, the recreational attraction of the urban park wetlands in Beijing was quantitatively assessed, and validated with questionnaire data. In Beijing, the urban park wetlands with high recreational attraction were in the order of the Summer Palace, Olympic Park, Qinglong Lake Park, Beihai Park, Yuanmingyuan Park, Yuyuantan Park, Shidu, Golden Sea Lake scenic area, Taoranting Park, and Yeyahu wetland. The Rice Fragrance Lake wetland and Zhenzhuhu scenic area had the lowest recreational attraction, and the others were fair.

[Applicability of traditional landscape metrics in evaluating urban heat island effect].

By using 24 landscape metrics, this paper evaluated the urban heat island effect in parts of Beijing downtown area. QuickBird (QB) images were used to extract the landscape type information, and the thermal bands from Landsat Enhanced Thematic Mapper Plus (ETM+) images were used to extract the land surface temperature (LST) in four seasons of the same year. The 24 landscape pattern metrics were calculated at landscape and class levels in a fixed window with 120 mx 120 m in size, with the applicability of these traditional landscape metrics in evaluating the urban heat island effect examined.

[Correlating landscape pattern with total nitrogen concentration using a location-weighted sink-source landscape index in the Haihe River Basin, China].

Understanding the effect of land cover pattern on nutrient losses is of great importance in management of water resources. The extensive application of mechanism models is limited in large-scale watersheds owing to the intensive data and calibration requirements. On the other hand, the traditional landscape indexes only take the areas and types of land cover into account, considering less about their topographic features and spatial patterns.

[Assessment of heavy metal pollution in surface sediments of rivers in northern area of Haihe River Basin, China].

Using Håkanson potential ecological risk index, the paper assesses heavy metal risk levels in northern parts of Haihe River basin based on 39 sampling sites. The results indicate that, the concentrations of Cu, Zn, Cd, and Cr in Haihe River basin are higher than the background values of heavy metals in China mainland, while the concentration of Pb is close to the background value in China mainland. Based on the potential ecological risk index for single heavy metal, the risk of Cu, Pb, Zn and Cr belongs to the "slight" level, while Cd has various risk levels at different sampling sites.

[Analysis of seasonal variations of surface water quality in the middle and upper reaches of Wenyu River].

The middle and upper reaches of Wenyu River was chosen as a case study area, and the temp-spatial difference of surface water quality was systematically studied by water sampling from June to August of 2009. It was found that distinct seasonal variations was exhibited on surface water quality in the study area. In the mountain regions, TP, TN, NO3(-)-N, NH4(+) -N and TOC concentration in the water increase from June to July, and then decline remarkably, whereas the DO and COD concentration in the water display an opposite pattern.

[Assessment of freshwater ecosystem services in Beijing based on demand and supply].

Freshwater ecosystem provides a variety of services to humanity, and in return, human activities give strong stress on the services, particularly in urban area. It is of significance to study the impact of human occupation and stress on freshwater ecosystem. In this paper, a water equivalent method was used to calculate the human occupation on the freshwater ecosystem services in Beijing from 1998 to 2007, and assessed the human stress effect on the freshwater ecosystem, based on the total amount of water resources.

[Dynamic changes of landscape pattern and eco-disturbance degree in Shuangtai estuary wetland of Liaoning Province, China].

The main objective of establishing natural reserve is to protect its natural resources from human disturbances and maintain its critical ecological service values. This paper introduced the concept of hemeroby, and by using remote sensing technology, systematically assessed the dynamic changes of landscape pattern and eco-disturbance degree in Shuangtai estuary wetland of Liaoning Province, China. Firstly, a knowledge-based expert system was used to classify the landscape into three first-level types based on eco-disturbance degree, i.

[Vertical zonation of mountain landscape: a review].

Vertical gradient of mountain landscape is about 1000 times of its horizontal gradient, and hence, only using landscape pattern index is quite difficult to reflect the landscape regularity along vertical gradient. Mountain altitudinal belt is a kind of classic geographic models representing the vertical differentiation of landscape, being of significance in geographic and ecological researches. However, the discrete expression pattern and the inaccuracy of the borderlines of mountain vertical belts limit the roles of mountain vertical belt in accurately describing landscape pattern in regional scale and in explaining ecological processes.