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
Gordan dana Kaplan* plan* , Zehra Yigit it Avdan an , , Serd erdar ar Goncu and d Ugur Avdan an
Introduction Aim of the study
Contents
Data and Methods Results Discussion
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
has been widely used in water quality research.
INTRODUCTION
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.
Borabey Lake which is located in Emirce Village on Bozdag slopes north
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.
Barrage Crest Length 411 m Dam Height 23 m Fill Volume 368.000 m3 Irrigation Area 248 ha Storage Volume 1.600.000 m3
Borabey Dam Technical Information
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
Red - Green Red + Green Actual Turbidity
Actual turbidity (NTU) Estimated turbidity
y =
R² = 0.8409 0.2 0.4 0.6 0.8 1.0 1.2 0.8 1 1.2 1.4 1.6 1.8 2 2.2 2.4
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 from remot
sing data with h the NDTI I statist stical al analys yses s were made. e. The resul ults s of the study show that the NDTI provide ded d strong positive e correl elation ation with h the actual al turbidi dity y in Borabey ey Lake (R2 = 0.84). ). Pearson
elatio ation n analys ysis s showed d that the correl elation n coefitien ent (r) is 0.92, 2, with high h level el of signifi nifica canc nce e (p < 0 0.05). ).
DISCUSSION
The resul sults of the study udy show w that at the e NDTI I prov
ided d strong
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
und that at blue/r e/red ed ratio io prov
ided ed strong
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
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
ing.
sence of the paper er is the use e of high-res esolut lutio ion n satell tellit ite e imag agery ery for
nitoring ing water ter turbidit bidity y in small all water er areas as. . For futur ure e stud udies ies, , we recom
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
hes for
imat atin ing g water er turbid bidity ity. .
Does anyone have any questions?
Eskisehir Technical University Earth and Space Scineces Institue kaplangorde@gmail.com