Semih Ekercin

Use of Landsat Land Surface Temperature and Vegetation Indices for Monitoring Drought in the Salt Lake Basin Area, Turkey

The main purpose of this paper is to investigate multitemporal land surface temperature (LST) changes by using satellite remote sensing data. The study included a real-time field work performed during the overpass of Landsat-5 satellite on 21/08/2011 over Salt Lake, Turkey. Normalized vegetation index (NDVI), vegetation condition index (VCI), and temperature vegetation index (TVX) were used for evaluating drought impact over the region between 1984 and 2011. In the image processing step, geometric and radiometric correction procedures were conducted to make satellite remote sensing data comparable with in situ measurements carried out using thermal infrared thermometer supported by hand-held GPS. The results showed that real-time ground and satellite remote sensing data were in good agreement with correlation coefficient (R 2) values of 0.90. The remotely sensed and treated satellite images and resulting thematic indices maps showed that dramatic land surface temperature changes occurred (about 2°C) in the Salt Lake Basin area during the 28-year period (1984–2011). Analysis of air temperature data also showed increases at a rate of 1.5–2°C during the same period. Intensification of irrigated agriculture particularly in the southern basin was also detected. The use of water supplies, especially groundwater, should be controlled considering particularly summer drought impacts on the basin.

Seasonal and spatial variability of metals concentrations in Lake Beyşehir, Turkey.

Lake Beyşehir is the largest fresh water lake and also the largest reservoir for drinking, and irrigation water in Turkey. The lake has an area of 656 km2 with an average depth of 5 m. Metal concentrations of aluminium (Al), cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), nickel (Ni), lead (Pb) and zinc (Zn) were determined in Lake Beyşehir on 9 June and 19 August 2005, and 12 June and 22 August 2006. The water samples were collected from 40 sampling stations. The aim of this research is to determine metal concentrations and their seasonal and spatial variability in the lake. Generally, metal concentrations of Lake Beyşehir were found to decrease in the sequence of Fe > Al > Zn > Cr > Ni > Pb > Cu > Cd as 92.8, 81.8, 7.4, 2.7, 2.2, 1.9, 1.7 and 0.5 µg L−1, respectively. The results showed that the mean concentrations of the metals in the lake water did not exceed WHO (World Health Organization), US EPA (Environmental Protection Agency) or TWQCR (Turkish Water Pollution and Control Regulations) drinking water guidelines. On the other hand, maximum levels of metals sporadically exceeded these standards in some sampling stations, especially for Al, Cr, Fe, and Pb.

Use of EO-1 Advanced Land Imager (ALI) multispectral image data and real-time field sampling for water quality mapping in the Hirfanlı Dam Lake, Turkey

This paper focuses on the evaluation of water quality variations in Hirfanlı Water Reservoir, which is one of the most important water resources in Turkey, through EO-1 (Earth Observing-1) Advanced Land Imager (ALI) multispectral data and real-time field sampling. The study was materialized in 20 different sampling points during the overpass of the EO-1 ALI sensor over the study area. A multi-linear regression technique was used to explore the relationships between radiometrically corrected EO-1 ALI image data and water quality parameters: chlorophyll a, turbidity, and suspended solids. The retrieved and verified results show that the measured and estimated values of water quality parameters are in good agreement (R2 > 0.93). The resulting thematic maps derived from EO-1 multispectral data for chlorophyll a, turbidity, and suspended solids show the spatial distribution of the water quality parameters. The results indicate that the reservoir has average nutrient values. Furthermore, chlorophyll a, turbidity, and suspended solids values increased at the upstream reservoir and shallow coast of the Hirfanlı Water Reservoir.

Investigating the Climate Change Impacts on the Water Resources of the Konya Closed Basin Area (Turkey) Using Satellite Remote Sensing Data

This chapter presents the pre-results from an ongoing study that mainly focuses on the use of remote sensing data to investigate the climate change effects on water resources in the Konya Closed Basin Area (KCBA), Turkey. In this study, multitemporal Landsat images along with climatic data were used to explore the dimension of drought effects on water lands and lakes located in the basin area. Image processing procedure includes both normalized difference vegetation index (NDVI) image interpretation and pre-processing stages (geometric and atmospheric correction). Our results suggest that in addition to socioeconomic profits of the use of groundwater for agricultural purposes, its effects on the ecological balance and water reserves in the KCBA should be analyzed in detail. Also, management strategies and plans should be developed to protect and/or rehabilitate current conditions in terms of drought in the KCBA. Furthermore, the region should regularly be monitored by up-to-date remote sensing data (at least annually) for better management of the water resources in the basin.

Channel Regulation Monitoring along the Lower Meric River, Turkey, Using Landsat-7 Enhanced Thematic Mapper Data

Abstract River channelization is a widespread practice including river bed regulation worldwide. A primary goal of channelization is to rehabilitate the floodplain of rivers, modifying the energy regime and sediment transport capacity. This paper presents an application of this process carried out in the floodplain of the Lower Meric River, Turkey. The application was performed by constructing a new channel in two regions along the river in the 1970s. Thus, the river was straightened, isolating its meanders to reduce the floods. These channel regulations are summarized in the paper by using satellite data and historical maps. The Landsat-7 enhanced thematic mapper (2001) image is the base data for interpretation of the present condition of the river channel, and the historical geomorphologic maps are used for the detection of the river bed prior to channelization.