The relationship of human activities and rainfall-induced landslide and debris flow hazards in Central China

2021 ◽  
Author(s):  
Liying Sun ◽  
Bingjuan Ma ◽  
Liang Pei ◽  
Xiaohang Zhang ◽  
John L. Zhou
2021 ◽  
Author(s):  
Andriyani Muliana

The environment is closely related to nature and its creation. Problems faced by humans related to environmental conditions are things that have a big impact. The influence of the environment is very large on human life which makes the benchmark for good or bad human behavior. Because human life depends on the circumstances around him. Problems are often new things, but the things we often encounter in the environment are a variety of problems, such as the most common environment. According to Tung and Wihardjo (in Ramadhan et al, 2019), problems that occur in the environment caused by careless and intensive human activities in the area where he lives, this is done to improve the quality of life of each. Humans are more selfish without the environment when doing things that damage the environment. Whereas the consequences of their own actions will cause various impacts that are detrimental to themselves and others, such as floods that occur due to waste.


Author(s):  
Marianela Gastaldi ◽  
Fausto Nahuel Firstater ◽  
Pedro Daleo ◽  
Maite Andrea Narvarte

Understanding the variables (biotic or abiotic) controlling coastal communities is the main goal of ecology research and it is crucial to predict how communities will evolve under the increasing pressure on coastal systems by human activities. The general aims of this study were to assess the variables affecting the distribution of the fast-growing sponge Hymeniacidon cf. perlevis, and to evaluate if physical stressful conditions have an influence in the relationship between Hymeniacidon and the sea lettuce Ulva lactuca. Specifically, the aims were to evaluate the abundance patterns of Hymeniacidon and Ulva and to assess the relationship of Ulva and physical variables on the abundance of Hymeniacidon at both intertidal and subtidal. Hymeniacidon and Ulva showed opposite abundance patterns. Hymeniacidon was more abundant in sites without Ulva, and negatively correlated with Ulva abundance at both heights. Intertidal Hymeniacidon abundance was not correlated with physical variables, but subtidal Hymeniacidon was.


2012 ◽  
Vol 594-597 ◽  
pp. 2309-2317
Author(s):  
Yan Li Yin ◽  
Bo Xu ◽  
Mo Wen Xie ◽  
Xiang Yu Liu

Debris flow is a huge geological disaster,the prediction of the quantity of debris flow is very significant. In this paper, combined with three-dimensional (3D) remote sensing image interpretation, a quantitative method has been proposed to calculate the quantity of debris flow. In the catchment of debris flow, the topography has been divided into zero-time valleys and one-time valleys, and the quantity of debris flow is calculated by two analytical ways of the full amount of portative matter and the amount of portative matter only caused by rainfall. In addition, based on the digital elevation model (DEM) and the amount of portative matter caused by rainfall, the spatial analysis function of the geographic information system (GIS) has been used to calculate the topographic parameters of the cross sectional area and the regional plane area of the catchment of debris flow. Then the relationship of the soil-rock output and the topographic parameters can be discriminated. Furthermore, the influencing range of debris flow can be stimulated. By practices, the analytical results can be used to estimate the dangerous area of potential debris flow.


Paleobiology ◽  
1980 ◽  
Vol 6 (02) ◽  
pp. 146-160 ◽  
Author(s):  
William A. Oliver

The Mesozoic-Cenozoic coral Order Scleractinia has been suggested to have originated or evolved (1) by direct descent from the Paleozoic Order Rugosa or (2) by the development of a skeleton in members of one of the anemone groups that probably have existed throughout Phanerozoic time. In spite of much work on the subject, advocates of the direct descent hypothesis have failed to find convincing evidence of this relationship. Critical points are:(1) Rugosan septal insertion is serial; Scleractinian insertion is cyclic; no intermediate stages have been demonstrated. Apparent intermediates are Scleractinia having bilateral cyclic insertion or teratological Rugosa.(2) There is convincing evidence that the skeletons of many Rugosa were calcitic and none are known to be or to have been aragonitic. In contrast, the skeletons of all living Scleractinia are aragonitic and there is evidence that fossil Scleractinia were aragonitic also. The mineralogic difference is almost certainly due to intrinsic biologic factors.(3) No early Triassic corals of either group are known. This fact is not compelling (by itself) but is important in connection with points 1 and 2, because, given direct descent, both changes took place during this only stage in the history of the two groups in which there are no known corals.


Author(s):  
D. F. Blake ◽  
L. F. Allard ◽  
D. R. Peacor

Echinodermata is a phylum of marine invertebrates which has been extant since Cambrian time (c.a. 500 m.y. before the present). Modern examples of echinoderms include sea urchins, sea stars, and sea lilies (crinoids). The endoskeletons of echinoderms are composed of plates or ossicles (Fig. 1) which are with few exceptions, porous, single crystals of high-magnesian calcite. Despite their single crystal nature, fracture surfaces do not exhibit the near-perfect {10.4} cleavage characteristic of inorganic calcite. This paradoxical mix of biogenic and inorganic features has prompted much recent work on echinoderm skeletal crystallography. Furthermore, fossil echinoderm hard parts comprise a volumetrically significant portion of some marine limestones sequences. The ultrastructural and microchemical characterization of modern skeletal material should lend insight into: 1). The nature of the biogenic processes involved, for example, the relationship of Mg heterogeneity to morphological and structural features in modern echinoderm material, and 2). The nature of the diagenetic changes undergone by their ancient, fossilized counterparts. In this study, high resolution TEM (HRTEM), high voltage TEM (HVTEM), and STEM microanalysis are used to characterize tha ultrastructural and microchemical composition of skeletal elements of the modern crinoid Neocrinus blakei.


Author(s):  
Leon Dmochowski

Electron microscopy has proved to be an invaluable discipline in studies on the relationship of viruses to the origin of leukemia, sarcoma, and other types of tumors in animals and man. The successful cell-free transmission of leukemia and sarcoma in mice, rats, hamsters, and cats, interpreted as due to a virus or viruses, was proved to be due to a virus on the basis of electron microscope studies. These studies demonstrated that all the types of neoplasia in animals of the species examined are produced by a virus of certain characteristic morphological properties similar, if not identical, in the mode of development in all types of neoplasia in animals, as shown in Fig. 1.


Author(s):  
J.R. Pfeiffer ◽  
J.C. Seagrave ◽  
C. Wofsy ◽  
J.M. Oliver

In RBL-2H3 rat leukemic mast cells, crosslinking IgE-receptor complexes with anti-IgE antibody leads to degranulation. Receptor crosslinking also stimulates the redistribution of receptors on the cell surface, a process that can be observed by labeling the anti-IgE with 15 nm protein A-gold particles as described in Stump et al. (1989), followed by back-scattered electron imaging (BEI) in the scanning electron microscope. We report that anti-IgE binding stimulates the redistribution of IgE-receptor complexes at 37“C from a dispersed topography (singlets and doublets; S/D) to distributions dominated sequentially by short chains, small clusters and large aggregates of crosslinked receptors. These patterns can be observed (Figure 1), quantified (Figure 2) and analyzed statistically. Cells incubated with 1 μg/ml anti-IgE, a concentration that stimulates maximum net secretion, redistribute receptors as far as chains and small clusters during a 15 min incubation period. At 3 and 10 μg/ml anti-IgE, net secretion is reduced and the majority of receptors redistribute rapidly into clusters and large aggregates.


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