scholarly journals Recent evolution of the Irrawaddy (Ayeyarwady) Delta and the impacts of anthropogenic activities: A review and remote sensing survey

Geomorphology ◽  
2020 ◽  
Vol 365 ◽  
pp. 107231 ◽  
Author(s):  
Dan Chen ◽  
Xing Li ◽  
Yoshiki Saito ◽  
J. Paul Liu ◽  
Yuanqiang Duan ◽  
...  
2021 ◽  
Vol 10 (6) ◽  
pp. 384
Author(s):  
Javier Martínez-López ◽  
Bastian Bertzky ◽  
Simon Willcock ◽  
Marine Robuchon ◽  
María Almagro ◽  
...  

Protected areas (PAs) are a key strategy to reverse global biodiversity declines, but they are under increasing pressure from anthropogenic activities and concomitant effects. Thus, the heterogeneous landscapes within PAs, containing a number of different habitats and ecosystem types, are in various degrees of disturbance. Characterizing habitats and ecosystems within the global protected area network requires large-scale monitoring over long time scales. This study reviews methods for the biophysical characterization of terrestrial PAs at a global scale by means of remote sensing (RS) and provides further recommendations. To this end, we first discuss the importance of taking into account the structural and functional attributes, as well as integrating a broad spectrum of variables, to account for the different ecosystem and habitat types within PAs, considering examples at local and regional scales. We then discuss potential variables, challenges and limitations of existing global environmental stratifications, as well as the biophysical characterization of PAs, and finally offer some recommendations. Computational and interoperability issues are also discussed, as well as the potential of cloud-based platforms linked to earth observations to support large-scale characterization of PAs. Using RS to characterize PAs globally is a crucial approach to help ensure sustainable development, but it requires further work before such studies are able to inform large-scale conservation actions. This study proposes 14 recommendations in order to improve existing initiatives to biophysically characterize PAs at a global scale.


2020 ◽  
Vol 62 (4) ◽  
pp. 288-305
Author(s):  
Addo Koranteng ◽  
Isaac Adu-Poku ◽  
Emmanuel Donkor ◽  
Tomasz Zawiła-Niedźwiecki

AbstractLand use and land cover (LULC) terrain in Ghana has undergone profound changes over the past years emanating mainly from anthropogenic activities, which have impacted countrywide and sub-regional environment. This study is a comprehensive analysis via integrated approach of geospatial procedures such as Remote Sensing (RS) and Geographic Information System (GIS) of past, present and future LULC from satellite imagery covering Ghana’s Ashanti regional capital (Kumasi) and surrounding districts. Multi-temporal satellite imagery data sets of four different years, 1990 (Landsat TM), 2000 (Landsat ETM+), 2010 (Alos and Disaster Monitoring Constellation-DMC) and 2020 (SENTINEL), spanning over a 30-year period were mapped. Five major LULC categories – Closed Forest, Open Forest, Agriculture, Built-up and Water – were delineated premised on the prevailing geographical settings, field study and remote sensing data. Markov Cellular Automata modelling was applied to predict the probable LULC change consequence for the next 20 years (2040). The study revealed that both Open Forest and Agriculture class categories decreased 51.98 to 38.82 and 27.48 to 20.11, respectively. Meanwhile, Built-up class increased from 4.8% to 24.8% (over 500% increment from 1990 to 2020). Rapid urbanization caused the depletion of forest cover and conversion of farmlands into human settlements. The 2040 forecast map showed an upward increment in the Built-up area up to 35.2% at the expense of other LULC class categories. This trend from the past to the forecasted future would demand that judicious LULC resolutions have to be made to keep Ghana’s forest cover, provide arable land for farming activities and alleviate the effects of climate change.


Land ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 130
Author(s):  
Thanh Thi Nguyen ◽  
Melvin Lippe ◽  
Carsten Marohn ◽  
Tran Duc Vien ◽  
Georg Cadisch

The present study revealed how local socioecological knowledge elucidated during participatory rural appraisals and historical remote sensing data can be combined for analyzing land use change patterns from 1954 to 2007 in northwestern Vietnam. The developed approach integrated farmer decision rules on cropping preferences and location, visual and supervised classification methods, and qualitative information obtained during various forms of participatory appraisals. The integration of historical remote sensing data (aerial photo, Landsat, LISS III) with farmer decision rules showed the feasibility of the proposed method to explain crop distribution patterns for the assessment period of 53 years. Our approach is beneficial for data-limited environments, which is a prevalent situation for many developing regions. The derived land use and crop type dataset was used for understanding how anthropogenic activities altered the study area of the Chieng Khoi commune during the assessment period of five decades, and what potential impact this can have on the natural resource base. The newly developed approach offers a methodological pathway that can be easily transferred to local government authorities for a better understanding of cropping transitions and agricultural expansion trends in data-limited rural landscapes. The detected land use change patterns and upland cropping expansion of more than two hundred percent in 53 years not only revealed the consequences of the interactions and feedback between farmers and their land, but further highlighted the urgent need for implementing sustainable land management practices in the case study watershed of the Chieng Khoi commune and northwestern Vietnam in general.


2018 ◽  
Vol 7 (3.10) ◽  
pp. 155
Author(s):  
T Subramani ◽  
D Santhi

Groundwater is the main source for domestic, industrial and agricultural requirements. Hence the groundwater infected with the aid of anthropogenic activities. Due to the depletion of ground water wells natural recharge will be insufficient to fulfill the actual requirement. The usage of remote sensing and geographic information system (GIS) it's far viable to take quantity of various thematic maps of the identical region and overlay them on top of each other to form a trendy incorporated layer. The thematic layers had been first digitized from satellite imagery, bolstered by using way of auxiliary information, as an example, topo sheets and region investigation facts, at thematic layers had been integrated the using. A contextual evaluation became directed to find out the groundwater capability zones in Namakkal District. 


2021 ◽  
Vol 13 (9) ◽  
pp. 1631
Author(s):  
Gemma Kulk ◽  
Grinson George ◽  
Anas Abdulaziz ◽  
Nandini Menon ◽  
Varunan Theenathayalan ◽  
...  

The United Nation’s Sustainable Development Goal Life Below Water (SDG-14) aims to “conserve and sustainably use the oceans, seas, and marine resources for sustainable development”. Within SDG-14, targets 14.1 and 14.2 deal with marine pollution and the adverse impacts of human activities on aquatic systems. Here, we present a remote-sensing-based analysis of short-term changes in the Vembanad-Kol wetland system in the southwest of India. The region has experienced high levels of anthropogenic pressures, including from agriculture, industry, and tourism, leading to adverse ecological and socioeconomic impacts with consequences not only for achieving the targets set out in SDG-14, but also those related to water quality (SDG-6) and health (SDG-3). To move towards the sustainable management of coastal and aquatic ecosystems such as Lake Vembanad, it is important to understand how both natural and anthropogenic processes affect water quality. In 2020, a unique opportunity arose to study water quality in Lake Vembanad during a period when anthropogenic pressures were reduced due to a nationwide lockdown in response to the global pandemic caused by SARS-CoV-2 (25 March–31 May 2020). Using Sentinel-2 and Landsat-8 multi-spectral remote sensing and in situ observations to analyse changes in five different water quality indicators, we show that water quality improved in large areas of Lake Vembanad during the lockdown in 2020, especially in the more central and southern regions, as evidenced by a decrease in total suspended matter, turbidity, and the absorption by coloured dissolved organic matter, all leading to clearer waters as indicated by the Forel-Ule classification of water colour. Further analysis of longer term trends (2013–2020) showed that water quality has been improving over time in the more northern regions of Lake Vembanad independent of the lockdown. The improvement in water quality during the lockdown in April–May 2020 illustrates the importance of addressing anthropogenic activities for the sustainable management of coastal ecosystems and water resources.


Nativa ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 364 ◽  
Author(s):  
Israel Oliveira Ivo ◽  
Marcelo Sacardi Biudes ◽  
Nadja Gomes Machado ◽  
Vagner Marques Pavão

A substituição do Cerrado mato-grossense para práticas agrícolas e a dinâmica fenológica alteram os índices biofísicos da superfície como a temperatura da superfície (Tsup) e o índice de área foliar (IAF). Assim, o objetivo desse estudo foi avaliar a variação do IAF e da Tsup por sensoriamento remoto em uma área de Cerrado no interior do estado de Mato Grosso. Imagens do sensor Thematic Mapper (TM) Landsat 5 foram utilizadas para estimar o IAF e a Tsup de uma área de Cerrado (CE), cana-de-açúcar (CA), pastagem (PA) e soja (SJ) em 2011. O IAF e a Tsup apresentaram correlação inversa. O IAF diminuiu e a Tsup aumentou ao longo da estação seca. Os maiores IAF e menores Tsup foram observados no CE, enquanto que os menores IAF e maiores Tsup foram observados na SJ. Os padrões temporais e espaciais do IAF e da Tsup na área de estudo ocorreram dirigidos pela precipitação, atividades antropogênicas e pelo próprio ciclo fenológico da vegetação.Palavras-chave: superfície do solo, antropização, aquecimento da superfície, sensoriamento remoto. INFLUENCE OF DEFORESTATION ON LEAF AREA INDEX AND SURFACE TEMPERATURE IN THE CERRADO OF MATO GROSSO ABSTRACT:The substitution of the Cerrado of Mato Grosso for agricultural practices and phenological dynamics alter the biophysical indexes of the surface such as surface temperature (Tsup) and leaf area index (LAI). Thus, the objective of this study was to evaluate the variation of LAI and Tsup by remote sensing in a Cerrado area in the state of Mato Grosso. The images of the Thematic Mapper (TM) Landsat 5 sensor were used to estimate the LAI and Tsup of an area of Cerrado (CE), sugarcane (CA), pasture (PA) and soybean (SJ) in 2011. The LAI and Tsup presented an inverse correlation. LAI declined and Tsup increased throughout the dry season. The higher LAI and lower Tsup were observed in the CE, while the lower LAI and higher Tsup were observed in SJ. The temporal and spatial patterns of LAI and Tsup in the study area were driven by precipitation, anthropogenic activities and by the phenological cycle of vegetation itself.Keywords: soil surface, anthropization, surface heating, remote sensing.


2021 ◽  
Vol 49 (1) ◽  
pp. 70-79
Author(s):  
Luis Manuel Valenzuela Nuñez ◽  
Aldo Rafael Martínez Sifuentes ◽  
José Antonio Hernández Herrera ◽  
Cristina García de la Peña ◽  
Edwin Amir Briceño Contreras ◽  
...  

Abstract Degraded vegetation is the result of a process that affects structural and functional characteristics. Tree species from the Acacia genus are very important to the ecosystem in semi-arid lands due to their participation in the recovery of highly degraded areas. One of the most important species among this genus is A. schaffneri. The status of a forest stand is determined according to its structure, including height, stratum and density. Remote sensing is a valuable method for estimating volumetric stocks and associated changes in forest populations over established periods of time. The objective of this research was to estimate wood volume of A. schaffneri using remote sensing, and to complement that information with the results obtained from an estimation method based on forest measurements. The results obtained showed that the crown area was the dendrometric variable that can be used in a wood volume prediction model. In the exploratory analysis between dendrometric variables and remote sensing showed low and negative associations were observed in the four stations analyzed. There are conservation problems due to anthropogenic activities, among which stands out the intensive grazing that results in a decrease of the natural regeneration capacity of Acacia schaffneri.


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