Evaluation of RapidEye-3 Satellite Data for Assessing Water - PowerPoint PPT Presentation

Evaluation of RapidEye-3 Satellite Data for Assessing Water Turbidity of Lake Borabey Gordan dana Kaplan* plan* , Zehra Yigit it Avdan an , , Serd erdar ar Goncu and d Ugur Avdan an

Contents Introduction Aim of the study Data and Methods Results Discussion

INTRODUCTION In water resources management, remote sensing data and techniques are essential in watershed characterization and monitoring, especially when no data are available. Water quality is usually assessed through in-situ measurements which require high cost and time. Water quality parameters help in decision making regarding the further use of water- based on its quality. Turbidity is an important water quality parameter and an indicator of water pollution. In the past few decades, remote sensing has been widely used in water quality research.

Aim of the study Several remote sensing studies have quantified the relationship between actual and estimated turbidity from satellite remote sensing data. However, the use of middle or low spatial resolution data is not useful in monitoring small lakes, dams or rivers. Thus, in this study, we use high spatial resolution satellite data for estimating the correlation between the in situ turbidity, and turbidity estimated from Rapid-Eye Eye sensor. Specific objectives were: to retrieve turbidity from RapidEye-3, and to correlate satellite retrieved turbidity with in-situ turbidity measurements.

Study Area Borabey Lake which is located in Emirce Village on Bozdag slopes north of the Eskisehir city center was chosen as the study area in this paper. The lake covers an area of approximately 166.559 m2 at an altitude of approximately 924 m. Borabey Dam was built between 1991-1992 by the Provincial Directorate of Rural Services at the time in order to support the local agriculture. The lake, which was allocated to be used as the Water Sports Center of Anadolu University in 1999, later was planned to be used in order to contribute to the drinking and utility water network of Eskisehir. Borabey Dam Technical Information Barrage Crest Length 411 m Dam Height 23 m Fill Volume 368.000 m 3 Irrigation Area 248 ha Storage Volume 1.600.000 m 3

Data Rapid Eye Table 2. Spectral bands for the RapidEye Satellite Constellation Band No Band Name Spectral Range [µm] 1 Blue 440 – 510 2 Green 520 – 590 3 Red 630 – 685 4 Red-Edge 690 – 730 5 Near Infra-red 760 – 850

Data Rapid Eye + In-situ data

Methods Actual Turbidity Red - Green NDTI = Red + Green

Results In n order r to evaluat ate e the relatio ations nships hips between en the actual al water turbi bidi dity y collec ected ed in situ and the corres espo pond nded ed turbidit dity y in reflec ectanc nce e value ues s estimat ated ed 1.2 from remot ote sensin sing data with h the NDTI I statist stical al analys yses s were made. e. 1.0 The resul ults s of the study show that the y = - 0.537x + 1.4879 R ² = 0.8409 NDTI provide ded d strong positive e correl elation ation Estimated turbidity 0.8 with h the actual al turbidi dity y in Borabey ey Lake (R2 = 0.84). ). 0.6 Pearson on correl elatio ation n analys ysis s showed d that the correl elation n coefitien ent (r) is 0.92, 2, with 0.4 high h level el of signifi nifica canc nce e (p < 0 0.05). ). 0.2 0.8 1 1.2 1.4 1.6 1.8 2 2.2 2.4 Actual turbidity (NTU)

DISCUSSION The resul sults of the study udy show w that at the e NDTI I prov ovide ided d strong ong positive itive correlation elation with h turbid bidit ity y in Borab abey ey Lake e (R2 2 = 0 0.84) 4). . The results esults are simi imilar lar to other er invest estigat igations ions where, ere, Masoch ocha et. al [4], found und that at blue/r e/red ed ratio io prov ovid ided ed strong ong posit itiv ive relat lation ion betwee ween n meas asured ured and retrieved ieved turbidity bidity in two differ erent ent lakes es (R2 2 = 0.81; R2 = 0.65). 5). Dif iffer erent ent turbid bidity ity retrieval ieval approac oach h showed wed a good correlat elation ion for two differ erent ent study udy areas as (R2 2 = 0 0.87; ; R2 = 0.66) ) [12]. ]. Howev wever, er, the use e of NDTI TI showed wed highe her correlation elation with h the actual ual turbid bidity. ity. This is study udy repres present nts another her study udy case e that at confirms irms the use e of satell ellit ite e remot mote sens nsing ing in water er quality ity mapping ping and monit nitor orin ing. g. The essence sence of the paper er is the use e of high-res esolut lutio ion n satell tellit ite e imag agery ery for or monitor nitoring ing water ter turbidit bidity y in small all water er areas as. . For futur ure e stud udies ies, , we recom ommend mend inves estigat igating ing different erent water er quali lity y param ameter eters with h high-resolut esolution ion satell ellit ite e imag ager ery, y, as well as differ erent ent approac oaches hes for or estim imat atin ing g water er turbid bidity ity. .

THANKS! Does anyone have any questions? Asst. Prof. Gordana Kaplan Eskisehir Technical University Earth and Space Scineces Institue kaplangorde@gmail.com