International Journal of Environment and Geoinformatics

114-131

Authors: Bhumika N. Vaghela, Mona G. Parmar, Hitesh A. Solanki, Bhagirath B Kansara, Sumit K. Prajapati , Manik H. Kalubarme

Mangroves are coastal wetland forests established in the intertidal zones of estuaries, backwaters, deltas, creeks, lagoons, marshes and mudflats of tropical and subtropical latitudes. World-wide mangroves are disappearing at an alarming rate. Mangroves form one of the most important ecosystems of coastal areas. In real sense, mangrove is the Kalpvriksh (divine tree which fulfills all the desires) for the coastal communities. It nurtures and safeguards the local ecology of the coastal areas and provides livelihood options to the fishermen and pastoral families. Amongst the maritime States of India, Gujarat has the second highest mangrove cover after West Bengal. Additionally, during last three decades Gujarat has more than doubled its mangrove cover. In Gujarat State, mangroves are well developed in Lakhpat taluka (block) situated in Kachchh district. In recent past, Gulf of Kachchh experienced both natural and anthropogenic changes which made it a distinctive site to analyze how natural processes and anthropogenic activities determine the changes in mangrove vegetation density and health of mangroves in coastal areas. Multi-temporal Landsat TM data covering Lakhpat taluka (block) of February-1995, February-2017and Sentinel-2 multi-spectral data (spatial resolution 10 m) of April-2017 was analysed. The mangrove vegetation around the coastal areas was identified and classified into dense and sparse density classes based on Normalized Difference Vegetation Index (NDVI) thresholding approach. The health assessment of mangroves in Lakhpat taluka was attempted using Multi Criteria Decision Making (MCDM) approach including various parameters like mangrove density based on NDVI, Distance of mangroves from human settlement, Distance of mangrove from Industries and Ports which have direct impact of growth and health of mangroves, Erosion/ Accretion over the period of last 22 years and availability of Saline water flow during the high tide for good mangrove growth. The buffers layers of various distances for example, 0 to 10 km, 10 to 20 km and 20 to 35 km were generated from the existing mangroves using Sentinel-2 multi-spectral image in GIS environment. The results indicate that the NDVI which is single parameter indicating the mangrove stand / vigour, growth condition and resulting health of mangroves in the area. This factor has been given highest weightage as compared to other parameters. The major anthropogenic factors like human Pressure and presence of Industries and Ports have negative impact on the mangrove health. Therefore, it was observed that presence of human settlements and Industries and Ports with the buffer region of 0 to 10 km distances from mangroves are unhealthy or prone to degradation in this region. The results of health assessment are very useful for sustainable planning and management of mangroves in the coastal areas of Lakhpat Taluka. The mangrove restoration and regeneration activity needs to be carried out as suggested by Upadhyay et al., 2015 with active participation of Community Based Organizations (CBOs) to increase the mangrove density as well as mangrove health in this region.

154-168

Authors: Fatima Hayat Shaheen Zafar, Zarrien Ayub, Aasia Karim, Mohammad Zahid, Levent Bat

The aim of the current study was to determine common physico-chemical parameters (salinity, temperature, chlorophyll-a, dissolved oxygen, and pH) of coastal water of two rocky shores from Buleiji and Paradise Point rocky shores at Karachi monthly basis, from November 2007 to April 2009. The range of air and surface water temperature of Buleji varies from 19 ºC to 30 ºC and 21ºC to 29 ºC, respectively. Almost similar air temperature and seawater temperature (19º to 29º C) were recorded at Paradise Point. Salinity ranged from 35 to 39 ‰ at Buleji while it ranged between 35 to 40 ‰ at Paradise Point. The lowest concentrations of dissolved oxygen was recorded in November’07 and November’08 at both sites, at Buleiji which were 1.6 mg/L and 1.7 mg/L while at Paradise Point it was 1.8 mg/L and 1.7 mg/L, respectively. The pH value ranged from 7.0 to 8.3 at Buleji and from 7.5 to 8.4 at Paradise Point. The concentrations of chlorophyll-a were between 1.2 and 3.7 μg cm-2 at Buleji while it ranged from 0.9 to 3.3 μg cm-2 at Paradise Point. Results showed that the obtained values of temperatures, salinity, pH and chlorophyll-a are favorable for the continued survival of marine biota but the values of dissolved oxygen were found to be below 4 mg/L which are not suitable for various species. Prolonged periods of minimal dissolved oxygen directly upset larval stages of numerous marine organisms. In Karachi coastal areas, seasonal accessibility of surface water is very responsive to the monsoon climate and physiography of coastal belt. These concerns were used to inform the common people and decision-makers about the state of the coastal environments. To protect these dynamic significant habitats, the government organizations and researchers should work with appropriate consideration.

178-188

Authors: Aliihsan Şekertekin, Aycan Murat Marangoz, Saygın Abdikan

The aim of this study is to estimate and map soil moisture distribution using C-band Synthetic Aperture Radar (SAR) data. Sentinel-1A is a new generation C-band SAR satellite, and in this study Sentinel-1A data acquired on 24 April 2016 were used to retrieve soil moisture map. An agricultural region in Bergama, a district of İzmir city, was chosen as the study area. In-situ soil moisture measurements were carried out in 20 test fields simultaneously with SAR data acquisition. The effects of soil moisture and local incidence angle on backscattering coefficient were analyzed, and then a multiple regression analysis was performed to generate an empirical model. The proposed model was evaluated using statistical metrics namely coefficient of determination (R2) and Root Mean Square Error (RMSE), and the results were 0.84 and 2.46 %, respectively. The obtained results showed that Sentinel-1A SAR data presented satisfying outcomes to estimate and map soil moisture content.

197-217

Authors: Salih Çelebioğlu

In this study, it is tried to give a system of Markov chains approach to the trend of annual mean temperatures in Turkey. For this reason, a data of annual mean temperatures between the years 1965 - 2012 of 58 meteorological stations of Turkey are used. Each scenario is given as a solution to a quadratic programming problem for which is spanned by the transition matrices of twelve groups. The steady-state distribution method given here facilitates the multiple station Markov chain applications. In the meantime, the linear regression approaches in which the averages of station groups are considered as independent variables are as well introduced. It is also given comments on some scenarios while an extreme scenario as a solution to a few problems is pointed out to which is feared in respect of climatic change

231-243

Authors: M.Tolga Esetlili, Filiz Bektas Balcik, Fusun Balık Şanlı, Mustafa Üstüner, Kaan Kalkan, Çiğdem Göksel, Cem Gazioğlu, Yusuf Kurucu

With the latest development and increasing availability of high spatial resolution sensors, earth observation technology offers a viable solution for crop identification and management. There is a strong need to produce accurate, reliable and up to date crop type maps for sustainable agriculture monitoring and management. In this study, RapidEye, the first high-resolution multi-spectral satellite system that operationally provides a Red-edge channel, was used to test the potential of the data for crop type mapping. This study was investigated at a selected region mostly covered with agricultural fields locates in the low lands of Menemen (İzmir) Plain, TURKEY. The potential of the three classification algorithms such as Maximum Likelihood Classification, Support Vector Machine and Object Based Image Analysis is tested. Accuracy assessment of land cover maps has been performed through error matrix and kappa indexes. The results highlighted that all selected classifiers as highly useful (over 90%) in mapping of crop types in the study region however the object-based approach slightly outperforming the Support Vector Machine classification by both overall accuracy and Kappa statistics. The success of selected methods also underlines the potential of RapidEye data for mapping crop types in Aegean region.