scholarly journals Assessing Hydrological Impact of Forested Area Change: A Remote Sensing Case Study

Atmosphere ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 817
Author(s):  
Mugurel Raul Sidău ◽  
Csaba Horváth ◽  
Maria Cheveresan ◽  
Ionuț Șandric ◽  
Florin Stoica

The interaction between precipitation and vegetation plays a significant role in the formation of runoff, and it is still a widely discussed issue in hydrology. The difficulty lies in estimating the degree to which a forest influences runoff generation, especially flood peaks, on the one hand, due to the small amount of information regarding the evolution of the forest area and density, and, on the other hand, the correlations between these indicators and the runoff and precipitation values. The analysis focuses on a small basin in the mountain region of Romania, the upper basin of the Ruscova River located in northwestern Romania. In this river basin, there is no significant anthropic influence, other than the intense deforestation and reforestation actions. Using satellite images captured by Landsat missions 5, 7 and 8 for the period 1985–2019, the forest canopy density vegetation index was extracted. Using a gridded precipitation dataset, a hydrological model was calibrated based on three scenarios to assess the impact of forest vegetation on the runoff. Analysis of the results of these models conducted on scenarios allowed us to deduce a simple equation for estimating the influence of forest area on maximum river flows. The analysis showed that even small differences in the forest surface area exert an influence on the peak flow, varying between −5.28% and 8.09%.

2020 ◽  
Vol 4 (1) ◽  
Author(s):  
Muhammad Attorik Falensky ◽  
Anggieani Laras Sulti ◽  
Ranggas Dhuha Putra ◽  
Kuswantoro Marko

<p><em>Indonesia is one of the owners of the 9th largest forest area in the world. Forest area in Indonesia reaches 884,950 km<sup>2</sup>. Tebo Regency is a regency in Jambi Province which has a wide forest area of 628,003 Ha. However, this forest area has been reduced due to the conversion of functions of Industrial Plantation Forests (HTI), oil palm plantations, and forest clearing activities for both settlements and plantations which led to the phenomenon of forest and land fires (karhutla). This study aims to get a better knowledge of crowns of fire potential locations in forest areas using remote sensing technology. Remote sensing data used in this study is from the satellite imagery </em><em>of </em><em>Landsat 8 OLI - TIRS in 2019. Remote sensing data is used to produce a Forest Canopy Density (FCD) model that can be overlap</em><em>ped with</em><em> a hotspot location, so the crown fire potential locations will be explored in the forest area of Tebo Regency, Jambi Province. Identification of hotspot patterns in Forest Areas was analyzed using spatial analysis. The results of this study are useful for the government as the information of the hotspot area as the cause of fires in the Forest Region of Tebo Regency Jambi Province.</em></p><strong><em>Keywords</em></strong><em>: Spatial Analysis, Forest Cover Density (FCD), Hotspots, Forest Areas, Remote Sensing</em>


Author(s):  
Anggoro Cahyo Fitrianto ◽  
Doddy Mendro Yuwono ◽  
Arif Darmawan ◽  
Koji Tokimatsu

In the oil palm industry, stands age is an important parameter to monitor the sustainability of cultivation, to develop the growth yield model, to identify the disease or stressed area, and to estimate the carbon storage capacity. This research is focused to estimate and distinguish oil palm stands age based on crown/ canopy density obtained using Forest Canopy Density (FCD) model derived from four indices as follows; Advanced Vegetation Index, Bare Soil Index, Shadow Index, and Thermal Index. FCD model employs multi temporal image analysis resulting four classes of oil palm stands age categorized as seed with FCD value of 29&ndash;56% (0 years), young with FCD value of 56&ndash;63% (1&ndash;9 years), teen with FCD value of 63&ndash;80% (10&ndash;15 years), and mature with FCD value of &gt;80% (&gt;15 years). Minimum canopy density value is 29% even in the zero years old indicates incomplete land clearance or the type of seed planted in the land.


Author(s):  
K. E. Mothi Kumar ◽  
R. Kumar ◽  
P. Kumar ◽  
V. Sihag ◽  
K. Singh ◽  
...  

<p><strong>Abstract.</strong> Forest plays an important role not only in providing ecological services but also economic goods to human beings. However, with increase in population there is a wide gap between demand and supply of these goods and services. This has lead to reduction in forest cover which needs to be taken care on regular time interval. To manage the existing forest area and also to increase the forest cover Forest Canopy Density (FCD) methodology is the main factor which was given by International Tropical timber Organization (ITTO). High resolution remote sensing LISS-4 data gives us chance to assess the quality of forest in terms of FCD as Rikimaru et al (1999) stated that FCD is one important parameter to assess forest cover quality. High resolution LISS-4 data analysis for FCD was never attempted before. Authors here attempted to assess the FCD utilizing methodology adopted by Rikimaru (1999), Huang (2001), Azizia (2008). The adopted methodology is one of the most efficient and cost effective way to derive the FCD. For this study Resourcesat-2 LISS-4 post monsoon data of year 2017 for Yamunanagar district was used to assess FCD within notified forest boundary. Notified forest boundaries at cadastral level prepared previously by Haryana Space Applications Centre (HARSAC) was used. The degree of forest canopy density is expressed in percentages: i.e. &amp;lt;<span class="thinspace"></span>10% FCD (scrub land), 10–20% (Open Forest-I), 20–40% (Open Forest-II), 40–60% (Moderate Dense), 60–80% (Medium Dense) and &amp;gt;<span class="thinspace"></span>80% (Highly Dense). Forest Canopy Density was based on three indices i.e. Advanced Vegetation Index (AVI), Bare Soil Index (BSI) and Canopy Shadow Index (CSI). Accuracy assessment was done based on ground data and comparison with Coterminous Google Earth imagery and it was found that the devised methodology has achieved overall accuracy of 93% with kappa coefficient of 0.9153. The result shows that maximum forest area in Yamunanagar district is in medium dense FCD category which is approximately 23948.08 acres. This study tells us that 24.2% of the total forest area is under scrub land and open forest which should be focussed for activities in working plan to increase the forest cover. This paper highlights the utility of high resolution satellite data for monitoring and management of forest and improvement in its quality. This attempt provided large scale (1<span class="thinspace"></span>:<span class="thinspace"></span>10,000) maps to the forest managers to better equip them in planning for afforestation, reforestation and rehabilitation of water logged areas, environment management and their future aspect.</p>


2020 ◽  
pp. 177-192
Author(s):  
Iman Hegazy

Public spaces are defined as places that should be accessible to all inhabitants without restrictions. They are spaces not only for gathering, socializing and celebrating but also for initiating discussions, protesting and demonstrating. Thus, public spaces are intangible expressions of democracy—a topic that the paper tackles its viability within the context of Alexandria, case study Al-Qaed Ibrahim square. On the one hand, Al-Qaed Ibrahim square which is named after Al-Qaed Ibrahim mosque is a sacred element in the urban fabric; whereas on the other it represents a non-religious revolutionary symbol in the Alexandrian urban public sphere. This contradiction necessitates finding an approach to study the characteristic of this square/mosque within the Alexandrian context—that is to realize the impact of the socio-political events on the image of Al-Qaed Ibrahim square, and how it has transformed into a revolutionary urban symbol and yet into a no-public space. The research revolves around the hypothesis that the political events taking place in Egypt after January 25th, 2011, have directly affected the development of urban public spaces, especially in Alexandria. Therefore methodologically, the paper reviews the development of Al-Qaed Ibrahim square throughout the Egyptian socio-political changes, with a focus on the square’s urban and emotional contextual transformations. For this reason, the study adheres to two theories: the "city elements" by Kevin Lynch and "emotionalizing the urban" by Frank Eckardt. The aim is not only to study the mentioned public space but also to figure out the changes in people’s societal behaviour and emotion toward it. Through empowering public spaces, the paper calls the different Egyptian political and civic powers to recognize each other, regardless of their religious, ethnical or political affiliations. It is a step towards replacing the ongoing political conflicts, polarization, and suppression with societal reconciliation, coexistence, and democracy.


Author(s):  
M. Taefi Feijani ◽  
S. Azadnejad ◽  
S. Homayouni ◽  
M. Moradi

Abstract. Forest canopy density (FCD) of seventeen protected areas of the Caspian Hyrcanian mixed forest are studied here. A modified version of FCD mapper based on spectral band fusion and customized threshold calibration that is optimized for Hyrcanian forests is used for this purpose. In this project, the results of applying the FCD model on three time series of satellite images have been analysed. This classification is based on the FAO standard and consist of four categories such as no-forest, thin, semi-dense and dense. These images, taken with TM and ETM sensors, belong to three-time series between 1987 and 2002. The results of this study indicate that the rate of growth or destruction of forests has been investigated in the regions. Then, using tables and diagrams of variations, the rate of growth or destruction of forest lands in the corresponding period in each class is determined. The FCD model has the ability to study the canopy loading classes in the annual time series.


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