As a kind of rarely-seen landform, the origin and evolution of stone forest receive wide-spread attention from international karstic research community. In China, the most typical and famous stone forest is the one called Lunan Stone Forest located in the east of the Yunnan Plateau, Southwestern China. It is believed that the development of the Lunan Stone Forest is closely related to the evlolution of the Bajiang River Catchment, where the stone forest lies. The authors have studied the structural characteristics of river system and geomorphology of Bajiang River, and the geographical feature of stone forest in the catchment and also its morphological features. It reveals that the stone forest, deeply influenced by the local lithology and stratum, mainly occurs in Permian Qixia and Maokou Formation; the spatial distribution of stone forest appears independent from landforms, and it is found in depressions, on the slope of as well as at the top of hills; however, the shape and tallness of stone pillars obviously change among the three kinds of landforms; the farther away from the Lunan Group, the shorter the stone pillars , and the bigger the distance among the pillars, from cluster-shaped to single pillar; the Tian-shengqiao Natural Bridge is actually a knickpoint for Bajing River, where exists a great difference in stone forest' s morphology and geographic feature between its upper and lower reaches. At the same time, according to the triple erosion mechanism of stone forest development, and based on the evolution history of hydrology, geology and geomorphology in Lunan area, the authors make a further analysis on the internal connection between the catchment evolution of Bajiang River and the development of stone forest, and divide the history of stone forest into three stages, that is, the ancient Lunan Lake stage, the stone forest omnipresent stage, and the catchment rejuvenation stage. The authors argue that the origin and extension of stone forest is not accidental but an evolutional product of Bajiang River Catchment.
龙宫是贵州著名的喀斯特风景点。该区在第四纪构造运动中由于地貌回春,形态逆向发育,水系频繁变迁。喀斯特地块渗漏导致地表流集中转入地下,从而使流水谷地首先盲谷化并逐步形成洼地。在这个过程中,流域地貌复杂响应基面变化,发育了龙宫坡立谷。这些坡立谷的形成与流域形态演化相联系而不同于I.Gams对划分的类型。它们在水系结构中与地下管道相串联,每逢雨季,将大量上游汇水滞蓄盆内,形成季节性喀斯特湖,对下游起到良好的天然调节作用。;Longgong is a famous scenic spot in the karst region of Guizhou Province. The landscape and rivers were rejuvenated in Longgong region by the tectonic movement in Quaternary Period, which arranged series of morphology in the catchment that consisted of fluvial valleys, blind valleys, poljes and depressions in turn from the divide to the base. Such poljes are dominated by two processes——the fluvial one from upper course which keeps the poljes possessing the form of the valley, and the karst one from downstream which made the poljes change into depressions or seasonal lakes because their drainage systems are still not fitted to the modification of the catchment. In the case the poljes perform a natural function of hydroJogic adjustment.
A review of literature published in 2014 focusing on analytical methods for pesticides in the water environment is presented here. The review includes publications on extraction methods and on analytical methods such as biochemical assays and immunoassays, electrochemical methods, chromatographic or mass spectrometric techniques, spectrophotometric techniques, fluorescence, and chemiluminescence techniques.
A review of literature published in 2010 on analytical methods for pesticides and herbicides is presented here in eight sections, including extraction methods, chromatographic or mass spectrometric techniques, electrochemical techniques, spectrophotometric techniques, chemiluminescence and fluorescence methods, sensors, biochemical assays and immunoassays, and miscellaneous techniques. Because many of the research studies in the cited publications utilized more than one analytical method, the different sections should not be thought of as being mutually exclusive.
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