[Ecological environment quality of the Shanxi section of the Yellow River Basin under different development scenarios]. / ä¸åŒå‘å±•æƒ æ™¯ä¸‹é»„æ²³æµåŸŸå±±è¥¿æ®µç”Ÿæ€çŽ¯å¢ƒè´¨é‡.

Shanxi Province holds an important strategic position in the overall ecological pattern of the Yellow River Basin. To investigate the changes of the ecological environment in the Shanxi section of the Yellow River Basin from 2000 to 2020, we selected MODIS remote sensing image data to determine the remote sensing ecological index (RSEI) based on the principal component analysis of greenness, humidity, dryness, and heat. Then, we analyzed the spatial and temporal variations of ecological quality in this region to explore the influencing factors. We further used the CA-Markov model to simulate and predict the ecological environment under different development scenarios in the Shanxi section of the Yellow River Basin in 2030. The results showed that RSEI had good applicability in the Shanxi section of the Yellow River Basin which could be used to monitor and evaluate the spatiotemporal variations in its ecological environment. From 2000 to 2020, the Shanxi section of the Yellow River Basin was dominated by low quality habitat areas, in which the ecological environment quality continued to improve from 2000 to 2010 and decreased from 2010 to 2020. The high quality habitat areas mainly located on the mountainous areas with superior natural conditions and rich biodiversity, while the low ecological quality areas were mainly in the Taiyuan Basin and the northern part of the study area, where the mining industry developed well. Climate factors were negatively correlated with ecological environment quality in the northern and central parts of the study area, and positively correlated with that in the mountainous area. Under all three development scenarios, the area of cultivated land, forest, water and construction land increased in 2030 compared to that in 2020. Compared to the natural development scenario and the cultivated land protection scenario, the ecological constraint scenario with RSEI as the limiting factor had the highest area of new forest and the lowest expansion rate of cultivated land and construction land. The results would provide a reference for land space planning and ecological environment protection in the Shanxi section of the Yellow River Basin.

[Blind area and layout optimization of parks based on the spatial supply-demand evaluation in Taiyuan City, China]. / åŸºäºŽä¾›éœ€å‡è¡¡çš„å¤ªåŽŸå¸‚å ¬å›­æœåŠ¡ç›²åŒºåŠä¼˜åŒ–å¸ƒå±€.

It is of great practical significance to identify service blind area, scientifically select park construction areas, and clarify the priority of parks' construction based on the co-ordination of supply-demand evaluation. With the urban parks within the Taiyuan Ring Expressway as the research subjects, we estimated the accessibility range and the service pressure of each park by using the application programming interface of Gaode map route planning and point of interest data to characterize their supply and demand levels. We identified the service blind areas of parks by overlay analysis, and used the location-allocation (LA) model to purposefully supply park green space. Results showed that the accessibility coverage rates of the parks by walking and bicycling within 15 minutes were 35.6% and 71.7%, respectively, indicating insufficient supply capacity of parks. The areas with large potential demand for park green space in Taiyuan were mainly concentrated in the business district of Qinxian-Changfeng Street and the Shuangta business district within Dongzhong ring road, which existed the obviously invisible blind areas. Finally, we proposed new park green space site selection proposal based on LA model. Optimization results indicated that the coverage rates of walking and bicycling within 15 minutes increased to 46.7% and 81.0%, respectively, and that the service pressure of parks was relieved. We combined the leisure demands of urban residents and the distribution of urban parks by utilizing network big data, which could promote the scientific nature and accuracy of the optimizing site selection and provide scientific method and theory basis for urban park construction.

Characteristics and indications of hydrogen and oxygen isotopes distribution in lake ice body.

Stable isotopes have been used to identify the characteristics of precipitation, evaporation, basin hydrology, and residence times. However, lakes in the cold regions are usually covered by ice for 5-6 months. To get a better understanding of stable isotopes characteristics and indications in lake ice bodies, ice and water were sampled during the icebound season in both the ice and water bodies in Dali Lake, and deuterium, oxygen-18 total nitrogen (TN), and the major ions were analyzed. The results showed that deuterium and oxygen-18 compositions (δD-δ¹8O) compositions in the ice body were greater than in the water body beneath, scattered on a straight line, and deviating downward from the global meteoric water line in the top right. The ice profile showed that the δD-δ¹8O compositions increased from the ice surface downward and decreased near to the bottom. In contrast, the TN and the major ions in the ice decreased from the ice surface downward and increased near to the bottom, meaning that the concentrations of δ¹8O had a negative correlation with the concentrations of TN and major ions. These indicated that stable isotopes can be used for tracing the nutriment and ion transport processes in the ice body.

[Bioavailability of dissolved organic nitrogen components in the lake sediment to alage].

Samples in the sediments of Wuliangsuhai and Erhai Lake were selected, and the technologies of XAD-8 resins separation and three dimensional fluorescence excitation-emission matrix (3DEEM) spectra were applied, in order to study the bioavailability of dissolved organic nitrogen components to alage under the room cultivation. The obtained results showed that: (1) Average loss of DON and DOC from sediments was below 5% after dividing DON into different groups, which means the technology of XAD- 8 resins separation could be used in the study of DON components in the lake sediment. (2) Through 3DEEM analysis, hydrophilic and hydrophobic DON was dominated by protein-like and humic-like materials in the lake sediment, respectively. (3) Under the hydrophilic component condition, growth curves of algae tended to show an "S" shape with a straight upward trend in the sediments of Wuliangsuhai and Erhai lake,with the maximum algal density reaching 535.5 x 10(4) and 709.5 x 10(4) per milliliter, respectively. Meanwhile, the DON concentrations were significantly reduced after cultivation to 2.46 and 2.98 mg x L(-1), respectively, which suggests that hydrophilic DON in the lake sediment was the bioavailable organic nitrogen for alage. (4) Under the hydrophbic component conditions, growth curves of algae tended to show a "unimodal" shape in the sediments of Wuliangsuhai and Erhai lake,with the maximum algal density reaching 113.5 x 10(4) and 275.5 x 10(4) per milliliter,respectively. The DON concentrations were significantly reduced during the early cultivation period, and then kept stable in the late period, which suggests that the hydrophobic DON component bioavailable to alage was low in short-term, and the hydrophobic DON component had hardly any positive effect on the growth of algae.