scholarly journals Modeling rates of ecosystem recovery after fires by using landsat TM data

1997 ◽  
Vol 61 (3) ◽  
pp. 383-398 ◽  
Author(s):  
O. Viedma ◽  
J. Meliá ◽  
D. Segarra ◽  
J. Garcia-Haro
2013 ◽  
Vol 25 (1-2) ◽  
pp. 136-148
Author(s):  
I. V. Gryb

The concept of an explosion in freshwater ecosystems as a result of the release of accumulated energy, accompanied by the destruction of the steady climax successions of hydrocenoses is presented. The typification of local explosions as well as methods for assessing their risk during the development of river basins are shown. The change in atmospheric circulation, impaired phases of the hydrological regime of rivers, increasing the average temperature of the planet, including in Polesie to 0,6 ºC, deforestation leads to concentration and release of huge amounts of unmanaged terrestrial energy, which manifests itself in the form of disasters and emergencies. Hydroecological explosion is formed as a result of multifactorial external influence (natural and anthropogenic) on the water body in a certain period of time. Moreover, its level at wastewater discharge depends on the mass of recycled impurities and behaved processing capacity of the reservoir, and the mass of dumped on biocides and the possibility of the water flow to their dilution and to the utilization of non-toxic concentrations. In all these cases the preservation of "centers of life" in the tributaries of the first order – local fish reproduction areas contributed to ecosystem recovery, and the entire ecosystem has evolved from equilibrium to non-equilibrium with further restructuring after the explosion and environmental transition to a new trophic level. It means that hydroecological explosion can be researched as the logical course of development of living matter in abiotic environmental conditions, ending abruptly with the formation of new species composition cenoses and new bio-productivity. The buffer capacity of the water environment is reduced due to re-development and anthropic transformation of geobiocenoses of river basins, which leads to a weakening of life resistance. This applies particularly to the southern industrial regions of Ukraine, located in the arid zone that is even more relevant in the context of increased average temperature due to the greenhouse effect, as well as to Polesie (Western, Central and Chernihiv), had been exposed to large-scale drainage of 60-80th years, which contributed to the degradation of peatlands and fitostroma. Imposing the western trace of emissions from the Chernobyl accident to these areas had created the conditions of prolonged hydroecological explosion in an intense process of aging water bodies, especially lakes, change in species composition of fish fauna and the occurrence of neoplasms at the organismal level. Under these conditions, for the existence of man and the environment the vitaukta should be strengthened, i.e. buffer resistance and capacitance the aquatic environment, bioefficiency on the one hand and balanced using the energy deposited - on the other. This will restore the functioning of ecosystems "channel-floodplain", "riverbed-lake", reducing the energy load on the aquatic environment. Hydroecological explosions of natural origin can not be considered a pathology – it is a jump process of natural selection of species of biota. Another thing, if they are of anthropogenic origin and if the magnitude of such an impact is on the power of geological factors. Hydroecological explosions can be regarded as a manifestation of environmental wars that consciously or unconsciously, human society is waging against themselves and their kind in the river basins, so prevention of entropy increase in the aquatic environment and the prevention of hydroecological explosions is a matter of human survival. While the man - is not the final link in the development of living matter, it can develop without him, as matter is eternal, and the forms of its existence are different.


2019 ◽  
Vol 3 ◽  
pp. 405
Author(s):  
Emma Rahmawati ◽  
Anang Dwi Purwanto
Keyword(s):  

Kegiatan penambangan timah di daratan di wilayah Kabupaten Belitung Timur sudah berlangsung sejak lama terutama di wilayah Kecamatan Kelapa Kampit. Banyak penduduknya bekerja sebagai penambang timah, namun kegiatan penambangan tersebut semakin berkurang seiring dengan adanya kebijakan terkait penambangan yang lebih ke arah pelestarian lingkungan dan adanya kegiatan reklamasi dan revegetasi yang dilakukan di lahan pasca tambang timah. Tujuan penelitian ini adalah untuk menganalisis gambaran perubahan penutup lahan dan menganalisis pola matapencaharian di Kecamatan Kelapa Kampit. Data penelitian yang digunakan terdiri dari data primer dan data sekunder. Data primer di antaranya berupa citra satelit Landsat TM akuisisi tahun 1995 dan Landsat 8 akuisisi tahun 2015 serta data hasil wawancara penduduk lokal. Data sekunder berupa data data dari pemerintah daerah setempat, dan lain-lain. Metode pemisahan obyek penutup lahan menggunakan teknik klasifikasi unsupervised (klasifikasi tak terbimbing). Setelah dilakukan proses reclass, maka dihasilkan 8 (delapan) kelas penutup lahan diantaranya: Awan (no data), Hutan, Ladang/Semak, lahan tambang, permukiman, perkebunan dan tubuh air. Analisis deskriptif kualitatif dilakukan untuk melihat hubungan perubahan penutup lahan dengan pola mata pencaharian masyarakat. Hasil penelitian menunjukkan terjadi kondisi yang kontradiktif antara lahan tambang dan hutan dengan lahan perkebunan kelapa sawit. Kondisi luasan lahan tambang dan hutan dari tahun 1994 – 2015 mengalami penurunan, sedangkan luasan lahan perkebunan kelapa sawit mengalami peningkatan yang cukup signifikan. Seiring dengan perubahan penutup lahan tersebut, terjadi penurunan jumlah buruh harian lepas dimana penambang inkonvensional termasuk didalamnya. Terjadi peralihan mata pencaharian yang awalnya mengandalkan penambangan, saat ini menjadi semakin banyak pilihan mata pencaharian yang dapat dipilih oleh masyarakat Kecamatan Kelapa Kampit.


2005 ◽  
Vol 70 (595) ◽  
pp. 91-96
Author(s):  
Minghao PIAO ◽  
Ikuo SAITO ◽  
Osamu ISHIHARA
Keyword(s):  

1998 ◽  
Vol 37 (6-7) ◽  
pp. 331-336 ◽  
Author(s):  
Stephen Garbaciak ◽  
Philip Spadaro ◽  
Todd Thornburg ◽  
Richard Fox

Sequential risk mitigation approaches the remediation of contaminated sediments in three phases designed to: (1) immediately reduce the ecological and human health risks associated with high levels of contamination, using methods such as the confinement or capping of high-risk materials; (2) reduce the risks associated with moderate levels of pollution to a minimum, on a less urgent schedule and at a lower cost; and (3) address areas of limited contamination through a combination of natural recovery and enhanced natural recovery (to aid or speed those natural processes). Natural recovery, the reduction of contaminant concentrations through natural processes, is based on the practical observation that overall ecosystem recovery appears to be largely a function of time. Sediment decomposition and the mixing of new and old sediments by bottom-dwelling organisms can both contribute to reduced contaminant concentrations. Knowledge of these processes--sediment decomposition, sediment mixing by bottom-dwelling organisms, and chemical residence time is critical in the development of appropriate ecosystem recovery and waste management strategies. Evaluations to support natural recovery predictions are designed to collect and evaluate information necessary to determine whether surface sediment chemical concentrations, with adequate source control, will reach the cleanup standards within a ten-year period.


2004 ◽  
Vol 12 (6) ◽  
pp. 563-573 ◽  
Author(s):  
Terence P. Boyle ◽  
Sandra M. Caziani ◽  
Robert G. Waltermire
Keyword(s):  

2021 ◽  
Vol 13 (10) ◽  
pp. 1973
Author(s):  
Sugang Zhou ◽  
Xiaojun Yao ◽  
Dahong Zhang ◽  
Yuan Zhang ◽  
Shiyin Liu ◽  
...  

The advancing of glaciers is a manifestation of dynamic glacial instability. Glaciers in the Tien Shan region, especially in the Central Tien Shan, show instability, and advancing glaciers have been recently detected. In this study, we used Landsat TM/ETM+/OLI remote sensing images to identify glaciers in the Tien Shan region from 1990 to 2019 and found that 48 glaciers advanced. Among them, thirty-four glaciers exhibited terminal advances, and 14 glaciers experienced advances on the tributary or trunk. Ten of the glaciers experiencing terminal advances have been identified as surging glaciers. These 48 glaciers are distributed in the western part of the Halik and Kungey Mountain Ranges in the Central Tien Shan, and Fergana Mountains in the Western Tien Shan, indicating that the Tien Shan is also one of the regions where advancing and surging glaciers are active. From 1990 to 2019, a total of 169 times advances occurred on 34 terminal advancing glaciers in the Tien Shan region; the highest number of advancing and surging of glaciers occurred in July (26 and 14 times, respectively). With reference to the existing literature and the present study, the surge cycle in the Tien Shan is longer than that in other regions at high latitudes in Asia, lasting about 35–60 years. Surging glaciers in the Tien Shan region may be affected by a combination of thermal and hydrological control. An increase in temperature and precipitation drives surging glaciers, but the change mechanism is still difficult to explain based on changes in a single climate variable, such as temperature or precipitation.


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