Elham Kianisalmi; Ataollah Ebrahimi
Abstract
Wetland meadows as a natural ecosystems plays an important role on sustainability of nature, although are enormously under drainage and changing in the recent years. Shahrekord meadow, which is located adjacent to the city, considered as a natural heritage due to its contribution to tourist visiting, ...
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Wetland meadows as a natural ecosystems plays an important role on sustainability of nature, although are enormously under drainage and changing in the recent years. Shahrekord meadow, which is located adjacent to the city, considered as a natural heritage due to its contribution to tourist visiting, balancing weather in addition to supplying forage for animals. However, this meadow is declining due to anthropogenic effects that this article aims at studying and evaluation of its change and prediction of future condition using Landsat TM5, ETM+7 and OLI/TIRS. To do so, first of all the images of 1987, 1994, 2001, 2010 and 2016 were gathered, then radiometric and geometrically were evaluated. After that, landuse/landcover of the study area was depicted using a maximum likelihood method in TerrSet (Ver. 18.31). Afterward, change detection of the study area was done using a cross-tabulation method and the future condition was predicted using a CA-Markov model. Results indicated that a significant change was occurred in this study area whereas in 1987 whole of the study area was covered by meadowland but land cover changes altered this valuable ecosystem to constructed area (3.33%), arable land (25.02%) and airport (19.65%) in 2016. Results of change prediction also depicted that 5.08% of the study area will be converted to other land cover in 2026. Therefore, we recommend that land use and land cover of this valuable ecosystem should be conserved due to the function and services that this meadowland offered.
sahar sabaghzade; Mohammad Zare; Mohamad Hosein Mokhtari
Abstract
Vegetation is an important component of each global ecosystem. Determining of the biomass of plant is important to assess its impact upon climate, soil erosion, and as well for management of natural resources. The aim of this study was to estimate biomass using vegetation indices based on remote sensing. ...
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Vegetation is an important component of each global ecosystem. Determining of the biomass of plant is important to assess its impact upon climate, soil erosion, and as well for management of natural resources. The aim of this study was to estimate biomass using vegetation indices based on remote sensing. The Landsat 8 data of May 2013 and field studies coinciding with field imaging in Marac (South Khorasan province) were used. Tamarix plant biomass measured in 30 random plots of 11 vegetation indices including DVI, IPVI, NDVI, PVI, RVI, SAVI, TSAVI, WDVI, and Tasselcap were used to estimate biomass of Tamarix.Then, using cluster analysis, vegetation indices were divided into three groups among which SAVI, RVI , and IPVI were chosen. The results showed that indexes which consider soil factors are more accurate than other measures. In this study, biomass map was prepared using the SAVI index.
