Uzaktan algılama (UA) ve coğrafi bilgi sistemi (CBS) teknikleri kullanılarak erozyon riskinin belirlenmesi
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Date
2007-11-16
Authors
Özsoy, Gökhan
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Publisher
Uludağ Üniversitesi
Abstract
Toprak erozyonu sonucu Mustafakemalpaşa Nehri ile bu nehrin boşaldığı Uluabat Gölü'ne (Ramsar Kapsamında) sediment taşınımı ciddi bir sorun oluşturmaktadır. Sorunun ortaya çıkarılması ve toprak yönetiminin planlanmasında erozyon modelleri çok kullanışlı gereçlerdir. Bu amaçla Yenileştirilmiş Evrensel Toprak Kayıpları Eşitliği (YETKE-RUSLE) erozyon tahminleme modeli Türkiye'de ve Dünya'da en yaygın kullanılan erozyon tahminleme modelidir. Bu çalışma ile CBS ortamında YETKE parametreleri ile Mustafakemalpaşa Nehri drenaj havzasında yıllık potansiyel toprak kaybı belirlenmiş, toprak erozyon riski tahmininde UA ve CBS tekniklerinin uygulanabilirliği sınanmıştır. YETKE-R faktörü yerel meteoroloji istasyonlarının aylık yağış verileri kullanılarak Modifiye Fournier İndeksi'nden (MFİ) hesaplanmıştır, topoğrafik (LS) faktörler sayısal yükseklik modelinden, toprak (K) verileri sayısallaştırılmış toprak haritalarından ve arazi kullanım/örtü (C) verileri Landsat?7 ETM uydu verilerinden üretilmiştir. Mustafakemalpaşa Havzası'nda YETKE/CBS modeli ile belirlenen toplam potansiyel toprak kaybı 11.296.061,75 ton yıl-1, ortalama toprak kaybı ise 11,18 ton ha-1 yıl-1 olarak hesaplanmıştır. Alt havzalar bazında toplam potansiyel toprak kaybı Emet alt havzası için 5.656.609,72 ton yıl-1 (ortalama 11,41 ton ha-1 yıl-1), Orhaneli alt havzasında 5.278.342,50 ton yıl-1 (ortalama 11,26 ton ha-1 yıl-1) ve Mkp alt havzası için ise 361.109,53 ton yıl-1 (ortalama 7,89 ton ha-1 yıl-1) olarak hesaplanmıştır. YETKE modeli sadece erozyon miktarını ortaya koymaktadır, havzanın sediment verimini belirleyememektedir. Bunun için SİO (sediment iletim oranı) fonksiyonları kullanılarak tahmin edilen sonuçlar Mustafakemalpaşa Çayı üzerinde kurulu bulunan Döllük Sediment Gözlem İstasyonu'nun 41 yıllık sediment taşınım miktarı ölçüm raporlarıyla karşılaştırılmıştır. Sediment iletim oranı ve YETKE toprak kaybının bir fonksiyonu olarak tahmin edilen sediment miktarı ve verimi sırasıyla, 1.640.942,7 ton yıl-1, 170,1 ton yıl-1 km-2.iken Döllük sediment gözlem istasyonunda sırasıyla 1.082.010 ton yıl-1, 127,59 ton yıl-1 km-2 olarak ölçülmüşlerdir. Sonuçlar Mustafakemalpaşa Havzası'nda, CBS ile bütünleştirilmiş YETKE modeli ile potansiyel erozyon riskinin etkin, doğru ve kolay bir biçimde tahmin edilebildiğini göstermiştir. Ayrıca, çalışılan havzaya ait daha doğru ölçülmüş veriler (R: plüviyograf okumaları, C: ölçülmüş bitki örtüsü ve yönetimi değerleri) elde edilebildiği takdirde, CBS erozyon modellemesinde başta işçilik olmak üzere, ekonomik ve zaman tasarrufu sağlayan mükemmel bir araçtır.
Sediment transport from agricultural and forestry lands to Uluabat Lake (Ramsar Site) by Mustafakemalpaşa River is a serious problem within the basin. Predictive erosion models are useful tools for evaluating soil erosion and to establish soil erosion management plans. RUSLE is the commonly used erosion model for this purpose in Turkey as well as in the World. This research integrates the Revised Universal Soil Loss Equation (RUSLE) with a Geographic Information System (GIS) environment to investigate the spatial distribution of annual soil loss potential in Mustafakemalpaşa River Basin. Problems and capabilities in application to GIS and using Remote Sensing (RS) techniques were also discussed. The RUSLE-R factors were developed from local rainfall annual precipitation data using Modified Fournier Index (MFI), topographic (LS) factors were developed from a DEM, soil (K) data were determined from digitized soil maps and land use/cover (C) data were generated from Landsat-7 ETM images. According to the RUSLE/GIS model, the total soil loss potential due to erosion by water of the Mustafakemalpasa River basin is found as 11.296.061,75 tons year-1 that an average soil loss of 11,18 tons ha-1 year-1. According to sub basins it is found 5.656.609,72 tons year-1 for Emet sub basin (average 11,41 tons ha-1 year-1), 5.278.342,50 tons year-1 for Orhaneli sub basin (average 11,26 tons ha-1 year-1) and 361.109,53 tons year-1 (average 7,89 tons ha-1 year-1) for Mkp sub basin. Moreover RUSLE produces only local erosion amount values and cannot be used to estimate the sediment yield for a watershed. For this purpose SDR (sediment delivery ratio) equations were used and compared with the sediment monitoring reports of the Döllük stream gauging station, settled in Mustafakemalpaşa River, within 41 years collected data. While, predicted sediment amount and yield as a function of the sediment delivery ratio and soil loss amount of RUSLE were 1.640.942,7 tons year-1 and 170,1 tons year-1 km-2, these were measured as a 1.082.010 tons year-1 and 127,59 tons year-1 km-2 at the Döllük stream gauging station respectively. Comparative results showed that RUSLE integrated with GIS in the study area found to be effective in generating potential soil erosion risk rates. Furthermore, with the basin wide measured data (such as R factor: from pluviograph reading, C factor: from measured cropping and management values) GIS is powerful, accurately and easy tool mainly economic, time and manpower gaining in modeling soil erosion.
Sediment transport from agricultural and forestry lands to Uluabat Lake (Ramsar Site) by Mustafakemalpaşa River is a serious problem within the basin. Predictive erosion models are useful tools for evaluating soil erosion and to establish soil erosion management plans. RUSLE is the commonly used erosion model for this purpose in Turkey as well as in the World. This research integrates the Revised Universal Soil Loss Equation (RUSLE) with a Geographic Information System (GIS) environment to investigate the spatial distribution of annual soil loss potential in Mustafakemalpaşa River Basin. Problems and capabilities in application to GIS and using Remote Sensing (RS) techniques were also discussed. The RUSLE-R factors were developed from local rainfall annual precipitation data using Modified Fournier Index (MFI), topographic (LS) factors were developed from a DEM, soil (K) data were determined from digitized soil maps and land use/cover (C) data were generated from Landsat-7 ETM images. According to the RUSLE/GIS model, the total soil loss potential due to erosion by water of the Mustafakemalpasa River basin is found as 11.296.061,75 tons year-1 that an average soil loss of 11,18 tons ha-1 year-1. According to sub basins it is found 5.656.609,72 tons year-1 for Emet sub basin (average 11,41 tons ha-1 year-1), 5.278.342,50 tons year-1 for Orhaneli sub basin (average 11,26 tons ha-1 year-1) and 361.109,53 tons year-1 (average 7,89 tons ha-1 year-1) for Mkp sub basin. Moreover RUSLE produces only local erosion amount values and cannot be used to estimate the sediment yield for a watershed. For this purpose SDR (sediment delivery ratio) equations were used and compared with the sediment monitoring reports of the Döllük stream gauging station, settled in Mustafakemalpaşa River, within 41 years collected data. While, predicted sediment amount and yield as a function of the sediment delivery ratio and soil loss amount of RUSLE were 1.640.942,7 tons year-1 and 170,1 tons year-1 km-2, these were measured as a 1.082.010 tons year-1 and 127,59 tons year-1 km-2 at the Döllük stream gauging station respectively. Comparative results showed that RUSLE integrated with GIS in the study area found to be effective in generating potential soil erosion risk rates. Furthermore, with the basin wide measured data (such as R factor: from pluviograph reading, C factor: from measured cropping and management values) GIS is powerful, accurately and easy tool mainly economic, time and manpower gaining in modeling soil erosion.
Description
Keywords
CBS, Uzaktan algılama, YETKE, Toprak erozyon modellemesi, Mustafakemalpaşa Havzası, GIS, Remote sensing, RUSLE, Soil erosion modeling, Mustafakemalpaşa River Basin
Citation
Özsoy, G. (2007). Uzaktan algılama (UA) ve coğrafi bilgi sistemi (CBS) teknikleri kullanılarak erozyon riskinin belirlenmesi. Yayınlanmamış doktora tezi. Uludağ Üniversitesi Fen Bilimleri Enstitüsü.