AN APPLICATION OF ROLL-INVARIANT POLARIMETRIC FEATURES FOR CROP CLASSIFICATION FROM MULTI-TEMPORAL RADARSAT-2 SAR DATA

Crops are dynamically changing and time-critical in the growing season and therefore multitemporal earth observation data are needed for spatio-temporal monitoring of the crops. This study evaluates the impacts of classical roll-invariant polarimetric features such as entropy (H), anisotropy (A), mean alpha angle (α) and total scattering power (SPAN) for the crop classification from multitemporal polarimetric SAR data. For this purpose, five different data set were generated as following: (1) Hα, (2) HαSpan, (3) HαA, (4) HαASpan and (5) coherency [T] matrix. A time-series of four PolSAR data (Radarsat-2) were acquired as 13 June, 01 July, 31 July and 24 August in 2016 for the test site located in Konya, Turkey. The test site is covered with crops (maize, potato, summer wheat, sunflower, and alfalfa). For the classification of the data set, three different models were used as following: Support Vector Machines (SVMs), Random Forests (RFs) and Naive Bayes (NB). The experimental results highlight that HαASpan (91.43 % for SVM, 92.25 % for RF and 90.55 % for NB) outperformed all other data sets in terms of classification performance, which explicitly proves the significant contribution of SPAN for the discrimination of crops. Highest classification accuracy was obtained as 92.25 % by RF and HαASpan while lowest classification accuracy was obtained as 66.99 % by NB and Hα. This experimental study suggests that roll-invariant polarimetric features can be considered as the powerful polarimetric components for the crop classification. In addition, the findings prove the added benefits of PolSAR data investigation by means of crop classification

Assessment of the effects of physical-chemical parameters on 210Po and 210Pb concentrations in cultivated and uncultivated soil from different areas

In this study, a total of 144 bulk soil samples were collected in cultivated and uncultivated sites in different areas for evaluation of the activity concentrations of 210Po and 210Pb. Moreover, 4 core samples were collected from four distinct reference points in the Gediz Basin in Turkey and investigated organic matter content, 210Po and 210Pb concentrations depending on the depth. The activity concentrations of 210Po and 210Pb were measured by means of alpha spectrometry. While the activity concentrations of 210Po and 210Pb in cultivated sites are in the ranges of 12±3-86±4 Bq kg-1 dw and 17±3-36±3 Bq kg-1 dw, for uncultivated sites the ranges for 210Po and 210Pb are 10±4-134±21 Bq kg-1 dw and 23±3-78±5 Bq kg-1 dw, respectively. In general, it is observed that the mean 210Po and 210Pb activity concentrations in cultivated sites are lower than the uncultivated sites. The relationships between soil properties and the activity concentrations of the radionuclides indicate that 210Po and 210Pb adsorption to soil is strongly related to organic matter content of the soil. © 2012 Elsevier B.V.Energy Research and Development Center, Missouri University of Science and Technology 2007BİL021 106Y054This work was supported by grants from The Scientific and Technical Research Council of Turkey (TÜBİTAK) contract no. 106Y054 and The Ege University Science and Technology Research Center (EBİLTEM) contract no. 2007BİL021 . Thanks are also extended to Mr. Ramazan Manav, Dr. Mutlu İçhedef and Dr. İlker Sert for assistance with fieldwork and sample processing. -

DETERMINATION OF THE ARSENIC POLLUTION DUE TO GEOTHERMAL SOURCES IN THE AGRICULTURAL LANDS OF ALANGULLU-AYDIN REGION

WOS: 000348254600005Arsenic, along with Hg, Sb, B, Li and F, is one of the important components of geothermal waters. In regions where geothermal waters are found abundantly, the arsenic content of these waters easily mixes into the watersheds and rivers. WHO reports the limit values of 10 mu g/1 for drinking waters, 19 mu g/1 for protection of aquatic life and FAO (Food and Agriculture Organisation) permissible limit for irrigation water (100 mu g/1). Arsenic, which is a natural pollutant in general, is of utmost importance due to its proven adverse impacts in particular on human health. Health problems due to high levels of arsenic are encountered in many countries such as Bangladesh, India, United States of America, Argentina, Chile, Taiwan and China. In this study, the arsenic content of the water and soil samples were evaluated to determine the impact of arsenic (As) pollution from geothermal sources on agricultural lands in Aydin-Germencik Alangullu Region which is a sub-basin of Great Menderes Basin (Western Turkey), where sodium chloride type geothermal sources are found as open systems. Water samples were taken from 4 different geothermal sources with natural flow conditions into agricultural lands of the basin. The As contents of the geothermal waters were measured between 680 and 1150 mu g/l. Soil samples taken from four different areas differed in relation to the impact level of the source and were determined to be between 14.88 and 48.50 mg kg-(1). The distribution of the impacted agricultural lands in the sub-basin was mapped using geostatistical methods

REMOTE SENSING AND GEOGRAPHIC INFORMATION SYSTEM IN THE MANAGEMENT OF AGRICULTURAL RISKS RELATED TO CLIMATE CHANGE

WOS: 000456590500035Agriculture is an important national strategic sector for the nutrition, employment, and development of all countries worldwide. The world is faced with the danger of starvation, especially due to the climatic changes in the recent years and global warming. Turkey is also in a region that is influenced by climate change. To provide food for the growing world population adequately and regularly, sustainable development of the agricultural sector needs to be promoted by minimising the existing risks. In this context, it is extremely important to monitor cultivated areas in the management of agricultural risks and to determine the level of effects the climate change would cause. Losses that may occur in agricultural production can be predicted earlier by using remote sensing techniques. In addition to climatic data, information on the topography and soil and land features can be collected in a GIS database, which would facilitate the development of an effective risk management model. The objective of this study was to examine the assessment and monitoring of crop-cultivated lands in Kayseri-Bunyan Province (Turkey), which was chosen as a pilot region, and predict the probable reduction in the yields that might occur due to dry seasons, plant diseases, and various disorders.Ege University Scientific Research Projects Coordination UnitEge University [17-ZRF-034]; Agricultural Insurance Pool (TARSIM)This study was supported by Ege University Scientific Research Projects Coordination Unit (Project number 17-ZRF-034) and Agricultural Insurance Pool (TARSIM)

LAND DEGRADATION DUE TO COASTAL URBANISATION

WOS: 000381331000032Recently, rapid urbanisation has been triggered by a population increase in coastal areas caused especially by migration, commercial development and tourism. Sever damage to natural resources, particularly in the agricultural soils have resulted in a rise in rural unemployment, as well as creating economic and ecological problems. The original population, farmers working the land, have been replaced by a population which consists of those employed in tourism, and people who have retired to areas of natural beauty. The new population structure demands the improvement of urban requirements and more housing, with no particular regard nature. This study focuses on land use changes in the coastal regions of the Izmir region, which are subjected to rapid growth. Aerial photographs and satellite images from the period 1984 and 2011 have been used. A significant expansion of the urban areas, up to 552, 481 and 439% increase have been determined for the coastal districts of Cesme, Karaburun, Foca, respectively, due to tourism and secondary residences. When losses in the agricultural land of this region were investigated, results showed that 14 974 ha of land are in the I and II land use capability class (LUCC) and 10597 ha in the III and IV LUCC

AGROECOLOGICAL ASPECT OF OLIVE CULTIVATION

WOS: 000348254600032Olive cultivation is very common in the Aegean region of Turkey and the sloping lands of this region face with severe erosion due to intensive cultivation practices. Erosion rapidly leads to infertile lands owing to detritions of the most productive top layer of soil and removal of soil to low lands on the slope. The level of erosion in olive-plantation zones has reached to a level that threatens even the agriculture of this crop. In this study, soil loss which results from conversion of natural vegetation such as maquis and forests into olive plantation was determined by using remote sensing technique and GIS. Results of the study showed that lands which were converted into olive plantations have a soil lose of 12.159 t ha(-1) annually. If natural vegetation of the lands was protected, only 3.965 t ha(-1) year soil would be lost. This result states that every year 8.194 t ha(-1) of soil are lost because of land use changes into olive cultivation on sloppy lands. It is known that similar agricultural land use plans have been supported by government in the Aegean region, which results to huge amounts of soil loss. Also, this result shows ecological damage of soil practices causing accelerated erosion and olive cultivation without precautions against erosion

Land use/cover mapping using multisensor image fusion technique

28th European-Association-of-Remote-Sensing-Laboratories (EARSeL) Symposium and Workshops on Remote Sensing for a Changing Europe -- JUN 02-05, 2008 -- Istanbul Tech Univ, Remote Sensing Div, ITU Maslak Campus, Istanbul, TURKEYWOS: 000342298700022Remote Sensing is an important technique for mapping land use and land cover in the vast acreages. In this sense, the fusion of optical and radar remote sensing data offers the opportunity to combine complementary sensors with different features. In this study, beside the capability of the combined multi source imagery, the contribution of SAR images to the optical images for identifying land use/cover types was investigated. For this purpose, using the synergy between SAR and Optical data, the improvement in the classification accuracy was analyzed. The study area, covering urban and agricultural areas, lies in the Menemen Plain to the west of Gediz Basin in the Aegean Region of Turkey. The satellite data used in this study are multispectral SPOT, ENVISAT-ASAR, and ALOS-PALSAR images. The 3-2-1 band combination of a SPOT-2 image was fused with C band ASAR imagery and with the new mission L band PALSAR imagery. The land use/cover types were defined from both of the fused images. In this case, since the SAR images have different bands (C band and L band) the penetration property is the key factor to see the affects on extracting information from fused images. Before the fusion application, the speckle reducing filter techniques were used for the preprocessing of SAR images. For the filtering of SAR images, kernel windows with different size were tried. Then the SPOT image was registered to SAR images. For the registration of SAR images, image to image registration method was used with a root mean square error of less than 1 pixel. A pixel based fusion method was carried out. Both of the fused images (SPOT-ASAR and SPOT-PALSAR) were classified to determine the land use/cover map. The results were compared with a classified SPOT image, which is commonly used to define land cover types. While processing the classification, the training areas were selected covering a large portion of the individual fields and were away from the field boundaries to reduce the mixed pixels. The ground truth data were used for the accuracy assessment process.European Assoc Remote Sensing Lab