Spatio-Temporal Changes of Water Surface Area of Lakes by Using Remote
Sensing Techniques: A Case Study of Seyfe Lake Wetland and Its Catchment
Area
Abstract
Lakes and wetlands are natural sources and have an important role for
hydrological cycle. They are also affected by climate change and
anthropogenic activities such as precipitation regime, diminishing water
bodies, uncontrolled groundwater extraction, drainage and irrigation
channels, agricultural activities and discharge of domestic and
industrial waste. For this reasons monitoring the lake surface areas are
very crucial. In this paper; the Seyfe Lake was selected as a case
study. The study area is located at the southern part of the Seyfe basin
with a catchment area of 1447 km2 in Central Anatolia. Seyfe Lake
wetland is located in a closed basin. The lake area and its surroundings
is a Ramsar site and have the status of Grade 1 Natural Site and
Protected Natural Area. This study aimed to evaluate the spatio-temporal
changes of the surface area of Seyfe Lake by using Geographical
Information Systems (GIS) and remote sensing techniques. For this
purpose Landsat (MSS, TM, ETM+, OLİ/TIRS) satellite images used for a
period between 1987 and 2020. A total of 34 images were processed and,
using unsupervised classification method, water body was extracted
according to the spectral information of the image bands and the
historical change of the lake surface area was calculated by using Image
Analysis Function of ArcGIS 10.6.1 software. In addition to these
satellite images, long-term hydrometeorological data and field
observations were analyzed to determine the changes of the Seyfe Lake
surface area and understand the effects of climate change and
antropojenic activities. According to the old and recent satellite
images of Seyfe Lake area, the persisting shrinkage of lake area and
diminishing of the water resources over the years in the Seyfe Lake
basin still continue. Maximum and minumum surface area of the lake was
calculated 43 km2 and 18 km2 respectively during 1987-2020. In August
2008; the lake area is completely dried. Nowadays the 58% of the lake
area is dried up. These variations could probably be related with the
antropogenic effects and climatic changes in the study area. As a
result, Satellite based techniques might provide a historical data to
identify changes on the lake surface area. Remote sensing techniques are
also effective to evaluate temporal and spatial changes on water
resources resulted by human activities and local climate change. In-situ
observation and hydrogeological monitoring are another important tools
to support findings of remote sensing study. Keywords: Spatio-temporal
change, Wetland, Seyfe Lake, Unsupervised Classification, Remote Sensing