scholarly journals Monitoring the ecological state of a hypertrophic lake (Albufera of València, Spain) using multitemporal Sentinel-2 images

Limnetica ◽  
2019 ◽  
Vol 38 (1) ◽  
pp. 457-469
Author(s):  
Xavier Sòria-Perpinyà ◽  
Esther Patricia Urrego ◽  
Marcela Pereira-Sandoval ◽  
Antonio Ruiz-Verdú ◽  
Ramón Peña ◽  
...  
Limnetica ◽  
2020 ◽  
Vol 39 (1) ◽  
pp. 373-386
Author(s):  
Xavier Sòria-Perpinyà ◽  
Marcela Pereira-Sandoval ◽  
Antonio Ruiz-Verdú ◽  
Juan M. Soria ◽  
Jesús Delegido ◽  
...  

2020 ◽  
pp. 147
Author(s):  
C. Aldana ◽  
M. Revilla ◽  
J. Gonzales ◽  
Y. Saavedra ◽  
W. Moncada ◽  
...  

<p class="p1">El Niño phenomenon, droughts and the warm climate directly influence the good ecological state of the forests in the Piura Region. The objective is to relate the spectral signatures evaluated in the Sentinel-2 satellite images with the spectral signatures measured with the FieldSpec4 spectroradiometer, for the identification of dry forest in the lower basin of the Chira River, Piura región. The Sentinel-2 images corresponding to the 17MNR, 17MPR, 17MMQ, 17MNQ and 17MPQ tiles are pre-processed, mosaicked, resampled and cut with the SNAP software. Stacking of bands 2, 3, 4, 5, 6, 7, 8, 9, 11 and 12 generates a raster whose pixel reflectance values are related to their wavelengths. The classification of dry forest areas is done with the spectral signature measured with the FieldSpec4 spectroradiometer. The validation of the results is carried out by applying the non-parametric ANOVA and Mann-Whitney-Wilcoxon tests at four sampling points. The surface area of dry forest in the lower basin of the Chira River is 129 113.06 ha, which represents 3.8% of the total area of dry forest in northern Peru.</p>


2019 ◽  
Author(s):  
V.B. Kalmanova

В статье представлены результаты исследования экологогеохимического состояния снежного покрова как индикатора качества атмосферного воздуха г. Биробиджана. Выявлены основные природные и антропогенные факторы, предопределяющие экологическое состояние городской территории в зимний период (климатические, планировочная структура, стационарные и мобильные источники загрязнения). Определено, что выбросы основных загрязнителей во время отопительного сезона превышает летний в 6,5 раз. Проведены геохимические исследования снежного покрова на 60 экспериментальных площадках, заложенных в различных функциональных зонах города. Выявлено значительное превышение тяжелых металлов над фоновым уровнем: железа до 60, марганца до 50, меди до 40, цинка до 20, никеля до 12, свинца до 10, кобальта до 6 раз. С 2003 по 2018 годы содержание химических элементов в снеге увеличилось в 2 раза за счет мобильных источников загрязнения, ТЭЦ, котельных. Проведена сравнительная характеристика накопления тяжелых металлов в снеге за 2003 и 2018 годы и установлен ранжированный ряд загрязняющих токсичных веществ. Разработана шкала оценки загрязнения депонирующих сред по суммарному показателю концентрации тяжелых металлов, согласно которой в Биробиджане выявлено 5 уровней загрязнения снежного покрова. В целом экологическое состояние урбанизированной территории признано неудовлетворительным (8 площади территории относится к очень высокому, 14 к высокому, 21 к выше среднему, 27 к среднему уровням загрязнения, 30 к относительно чистым районам города). По полученным результатам разработана карта в программе ArcView GIS Экологогеохимическое районирование территории г. Биробиджана по уровню загрязнения снежного покрова с выделением наиболее загрязненных участков (70 от общей площади города является загрязненной). По результатам проведенных исследований предложены конструктивные методы планирования урбанизированной территории с целью улучшения ее экологического состояния: проведение геомониторинга (контроль загрязнения снежного покрова и своевременный его вывоз на специально оборудованные полигоны). Snow cover is taken as an indicator of air quality using Birobidzhan, a middlesize city in the Russian Far East, as a case study. The main natural and manmade determinants influencing the ecological state of the urban area in winter are identified: climate, a planning structure, and the stationary and mobile sources of pollution. During the heating season the emission of major pollutants exceeds the summer level by 6.5 times. The geochemical study of snow cover was performed at 60 experimental sites in different functional urban areas. A significant excess of heavy metals over the regional background level was revealed: iron up to 60 times, manganese up to 50, copper up to 40, zinc up to 20 , nickel up to 12, lead up to 10, cobalt up to 6 times. From 2003 to 2018 the content of chemical elements in snow increased in 2 times due to the mobile sources of pollution, thermal power plants, and boilers. The comparative characteristic of accumulation of heavy metals in snow for 2003 and 2018 is carried out, and the ranked number of polluting toxic substances is established. The scale of pollution assessment in depositing environments was developed using the cumulative indicator of heavy metal concentration. Five levels of snow cover pollution are found in Birobidzhan: low, moderate, above moderate, high and very high. As a whole, the ecological state of the urban area is considered as unsatisfactory (8 of the area with a very high level of pollution, 14 with high, 21 above moderate, 27 a moderate level of pollution, 30 a relatively clean area). According to the results, a map was developed in the ArcView GIS program Ecological and geochemical zoning of Birobidzhan, using the level of the snow cover pollution with the allocation of the most polluted areas (70 of the total area of the city is polluted). According to the results, a constructive method of planning in an urban area is proposed in order to improve its environmental condition: geomonitoring as a control of pollution in snow cover and its prompt removal to specially equipped landfills.


2016 ◽  
Vol 52 (4) ◽  
pp. 19-31 ◽  
Author(s):  
Ye. P. Belous ◽  
S. S. Barinova ◽  
P. D. Klochenko ◽  
V. A. Zhezherya ◽  
T. P. Zhezherya ◽  
...  

Author(s):  
Irina Mesenzeva ◽  
Irina Mesenzeva ◽  
Elena Sovga ◽  
Elena Sovga ◽  
Tatyana Khmara ◽  
...  

The ability of a bay and gulf ecosystems to self-purification was estimated and the current ecological state of the Sevastopol Bay in whole and the separated parts of the bay was given as an example. A zoning by type of anthropogenic impact subject to the water exchange with the open sea and an influence of the Chernaya River run-off were taken into account. A comparative analysis of assimilation capacity of the most environmentally disadvantaged part of the Sevastopol Bay (the Southern Bay) and the clean water area, bordering on the open sea, was carried out. The hydrodynamic regime of the Sevastopol Bay was described using numerical modelling. The prospect, opportunity and examples of the methodology for assessing the assimilation capacity of marine ecosystems are demonstrated.


1992 ◽  
Vol 27 (2) ◽  
pp. 301-310
Author(s):  
Agnes G. Pulvermüller ◽  
Heidulf E. Müller

Abstract The survey of the ecological condition of eight lakes within the city limits of Freiburg included hydrochemical measurements and analyses (oxygen profiles, Secchi depth, pH, biochemical oxygen demand) together with biological parameters (chlorophyll a, phytoplanktonbiomass, Escherichia coli counts), as well as parasitic examinations. Only some of the investigated parameters are presented here. Seven of the eight lakes were found to be eutrophic. The process of eutrophication appears to be still in progress. One lake can be considered to be hypertrophic. Schistosome dermatitis was observed. The water quality in general was considered to be acceptable; suggestions to maintain or improve the water quality are made.


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