《中国大百科全书·中国地理卷》西南区编撰对区域地理学研究的启示

《中国大百科全书》是中国文化遗产的宝库,地理卷作为其重要分册之一,是地理学的工具用书,更是普通大众了解地学知识的一个窗口,也是以书为鉴,明得失、知兴替的“铜镜”。基于《中国大百科全书·中国地理卷》第三版的编写,聚焦西南区,分析地理词条的构成与特征,探讨区域地理学研究的特色。梳理出西南区旅游与地理学协同发展,资源与生态保护地位凸现,地质灾害研究成效显著,地缘与经济战略优势突出等特点。并在浅析西南区地理学研究不足基础上,提出区内地理学发展的展望,即加强西南区地理学的基础性与综合性研究,提升地域系统对全球变化的动态响应研究,拓展新时期地理学的量化与应用性研究,重视地理科学知识科普的人才队伍建设等。

Analysis of Ecosystem Degradation Factors in Yuanmou Arid-Hot Valleys Based on Interpretative Structural Model

For ecological restoration and reconstruction of the degraded area, it is an important premise to correctly understand the degradation factors of the ecosystem in the arid-hot valleys. The factors including vegetation degradation, land degradation, arid climate, policy failure, forest fire, rapid population growth, excessive deforestation, overgrazing, steep slope reclamation, economic poverty, engineering construction, lithology, slope, low cultural level, geological hazards, biological disaster, soil properties etc, were selected to study the Yuanmou arid-hot valleys. Based on the interpretative structural model （ISM）, it has found out that the degradation factors of the Yuanmou arid-hot valleys were not at the same level but in a multilevel hierarchical system with internal relations, which pointed out that the degradation mode of the arid-hot valleys was ＂straight （appearance）-penetrating-background＂. Such researches have important directive significance for the restoration and reconstruction of the arid-hot valleys ecosystem.

Meanders of the Jialing River in China: Morphology and formation

As a fundamental category of river system, comparisons in diverse regions and types with quantitative parameters on meander morphology will help to distinguish different characteristics and approach formations and evolutions. It also can provide scientific basis of geomorphology for their protections and exploitation of the meander resources. Based on the images of Google Earth, meanders’ parame- ters are proposed and then measured and calculated. The result suggests that incised meanders in the Jialing River are among the most complex, irregular and sinuous channels. Special river gradient, geological structures, strata and lithology, backwater effect of landform are key factors to shape me- anders of the Jialing River. The evolution of meander in the Jialing River obeys the principle of mini- mum-maximum energy dissipation. Easy acquisitions of remote sensing data make regional and global comparisons possible, and then the differences of formations can be explored. The morphology can probably provide an evidence of antecedent river and demonstrate the channel incisions and crustal uplifts. Meander core in Chinese is named after the isolated hills in the Jialing River. The incised me- ander is a kind of resource and needs to be protected.

Scaling behavior of magnitude clusters in aftershock sequence:An example of the Wenchuan Earthquake,China

The Gutenberg-Richter and Omori Laws, which are generally used to characterize the temporal distribution of aftershock, failed to reflect the statistic properties of climatic outbreak of aftershock energy. Based on a new concept of magnitude clusters describing the fluctuation of aftershock energy release of the Wenchuan Earthquake, we discovered that the pattern of the continuous high-magnitude aftershock follows a power-law rather than a non-Poisson distribution. This suggests that the after-shocks with high magnitudes are statistically clustered. We then divided the aftershock sequences into three sections and demonstrated that though the probability of strong outbreaks decreased with time, there exists a high possibility of the occurrence of isolated high-magnitude aftershocks in the future. Based on self-organized criticality theory, the mechanisms of the power-law pattern of magnitude clusters are discussed. This discovery may be used to guide future aftershock predication and the associated post-disaster reconstruction.

Classification and detection of dominant factors in geospatial patterns of traditional settlements in China

The geospatial distribution pattern in traditional Chinese settlements(TCSs)reflects the traditional harmony between humans and nature,which has been learned over centuries.However,TCSs have experienced serious disturbances by urbanization and migration.It is crucial to explore the local wisdom of geospatial patterns and dominant factors for TCSs at the national scale in China.This study sought to determine the geospatial wisdom of traditional settlements to enrich our future settlement development with the aim of establishing Chinese settlement values for modern living.Herein,a dataset of 4000 TCSs were analyzed and clustered for environmental factors that affect their geospatial patterns by machine learning algorithms.We concluded that(1)five geospatial patterns of TCSs were clustered on a national scale,and the threshold of environmental factors of TCS groups was detected.(2)Environmental conditions and settlement concepts interacted and determined the similarities and differences among TCS groups.(3)The key boundary for TCSs and the dominant factors for each zone were determined,and topographical conditions and hydrologic resources played significant roles in all five TCS zones.This study provides a better understanding of the adaptability of the environment in relation to the TCSs and aids in planning TCS conservation and rural revitalization.