The Application of Cluster analysis and Inverse Distanceweighted Interpolation to Appraising the Water Quality of Three Forks Lake

Transcription

1 Avalable onlne at Proceda Envronmental Scences 10 (011 ) rd Internatonal Conference on Envronmental Scence and Informaton Conference Applcaton Ttle Technology (ESIAT 011) The Applcaton of Cluster analyss and Inverse Dstanceweghted Interpolaton to Apprasng the Water Qualty of Three Fors Lae Wang Ke a, He Png Cheng, Dong Yan and Chen Ln *a* Chengdu Electromechancal CollegeChengdu, Schuan, Chna Abstract. The purpose of ths paper s to realze the sustanable development of Three Fors Lae and control polluton.it analyzes the water qualty of Three Fors Lae n the followng aspects: PH, H3-, total phosphorus, total ntrogen, permanganate ndex, transparency, TDSDO, conductvty. The author dd some researches on water envronment of Three Fors Lae by means of Cluster analyss and Inverse Dstance-weghted Interpolaton. The study reveals that most water area of Three Fors Lae s polluted serously because the water here s havng a PH greater than 7 and a greater turbdty, and the water nearer to nland s harder, havng more ntrogen, hgher permanganate ndex, less dssolved oxygen. Ths paper not only theoretcally studess the water qualty of Three Fors Lae by cluster analyss, but also get a concluson of polluton wth the combnaton of the nformaton from Fgure 1,Fgure 3 and Fgure 4, whch bascally dentcal wth the authorty's data. 011 Publshed by Elsever Ltd. Open access under CC BY-C-D lcense. Selecton and/or peer-revew under responsblty of Conference ESIAT011 Organzaton Commttee. Keywords: Cluster analyss; Inverse Dstance-weghted Interpolaton; Three Fors Lae; water qualty 1. Introducton. General Plan for the Frst Stage at Three Fors Lae Cooperaton Zone ntends to develop an area wth mult-functons, such as toursm servces, busness, lesure, culture, sport, real estate[4]. Water plays a leadng role n envronment. The correct and approprate apprasal of water qualty s mportant to allocate, use, protect, manage water resources because t provdes scence foundaton for plannng water and preventng water envronment polluton. If we pay no attenton to water envronment, the whole tourst ndustry mght wal nto vcous crcle, even collapse. In order to realze the sustanable * E-mal address: a tongwang889@tom.com Publshed by Elsever Ltd. Open access under CC BY-C-D lcense. Selecton and/or peer-revew under responsblty of Conference ESIAT011 Organzaton Commttee. do: /j.proenv

2 51 Wang Ke et al. / Proceda Envronmental Scences 10 ( 011 ) development of Three Fors Lae and control polluton, we try to study the present polluton there wth the ad of Cluster analyss and Inverse Dstance-weghted Interpolaton.. atural Geographcal Stuaton Three Fors Lae s the second largest lae n Schuan Provnce, located n Sancha Town, Janyang Cty. It was lsted n Famous Laes n the World n The lae strandlne s 40 m, From north to south, the lae extends 18 m, and from east to west, 7 m. The water area s 7 sq. m. and the wdest part of the surface s about 6,000 m. Its water retenton capacty, 0.7 bllon cu m, s three tmes that of West Lae n Hangzhou. Three Fors Lae has 113 slands, more than 160 pennsulas, 3 sq m wetland. Ownng to good ecologcal condton, there are lots of brds and rch natural resources [5]. 3. Research Methods 3.1. Cluster analyss[3] Cluster analyss s manly used to study the classfcaton of varous objects or phenomena. The basc dea of ths approach s to set each sample as a class of ther own, and then defne the dstance between the samples (or a smlar factor) and the dstance between classes. Select from the smallest par, merge nto a new class, and calculate the new class and the dstance between the other classes, and then mergng the closest two. Ths wll reduce the nber of the classes, one at a tme, untl all of the samples are dstrbuted nto one same class. Accordng to the defnton of between-class dstance method, whch s dvded nto the shortest dstance, the dstance method, the mddle dstance, center of gravty method, group average method, varable group average method, Ward from the s of squares method, two-stage densty estmaton and so on. Cluster analyss of varous systems comparatve studes have shown that the majorty of cases wth good comprehensve propertes and the Ward method and squared devaton class average, whle the shortest dstance method s the worst. Therefore, the author selected Ward s of squares and the method of water polluton of Lae Sancha cluster analyss. 3.. square s of devatons Square s of devatons s the total s of squares. It s used to represent the dstance between the two samples, and gradually cluster. Assng a step class to class C K and class C L nto the next level class C M. The B KL s defned as the combned result of the ncremental square s of devatons when a step s class C K and class C L nto the next level class C M, B KL =W M -W K -W L,n whch W M s square s of devatons of class C M,W L s square s of devatons of class C L. To represent the dstance between two observaton ponts potatoes wth d(x,y) and represent D KL the dstance between class C K and C L. The Formula of Ward square s of devatons s: DKL BKL X K X L /(1/ K 1/ L ) (1) Where, L s the nber of observatons n class CL; XL s the mean vector of the class CL, when the observaton dstance s d( x, y) x y /,the recursve formula s: D JM () ( K DJK LDJL) / M LDKL / M

3 Wang Ke et al. / Proceda Envronmental Scences 10 ( 011 ) n ths formula, D JM s the dstance between class C J and class C M, DJK s the dstance between class C J and class C K, D JL s the dstance between class C J and class C L and M s the nber of observatons for C M. Ward method maes the class lead a mnm ncrease of square s of devatons when t s used to merge class Interpolaton Interpolaton s an mportant method of dscrete functon approxmaton. It can estmate the approxmaton value n other ponts through value status of the functon n certan ponts. Common nterpolaton methods nclude Lagrange nterpolaton (lagrange nterpolaton), lnear nterpolaton, Hermte and cubc splne nterpolaton, nverse dstance weghted average nterpolaton. Inverse Dstance-weghted Interpolaton s a method of partal nterpolaton, and ts asspton s that the pont of unnown value s nfluenced more by nearer observaton ponts than by closer observaton ponts. Snce the changes n water qualty eep are contnuous, and the water qualtes are more famlar n closer observaton ponts, the weghted average of nverse dstance nterpolaton s used n ths artcle Inverse Dstance-weghted Interpolaton[1,] Calculatng a grd node, the data pont to gve a specfc weght of the specfed node from the second sde to the observaton pont s gven of the node s proportonal to nverse dstance. When calculatng a grd node, the weght s assgned to a fracton, the s of weght equal to 1.0 of ownershp. When an observaton pont wth a grd node overlap, the actual observaton pont s gven a weght of 1.0, all other observaton ponts s gven a weght of almost 0.0. In other words, the node s assgned a value consstent wth the observaton pont. The formula s f f ( x, y) 1 f r 1 r 1 r 0 r 0 (3) Where, f(x,y) s the pont for the coordnates n the nterpolated value of (x,y), f s the dstance between the observaton ponts (x,y) for the r value. 4. Apprasng the Water Qualty of Three Fors Lae 4.1. Apprasal Standard and Parameter Selecton The major polluton source comes from cage culture of fsh, household garbage, and wastes left by toursts. [4]Accordng to the relatve standards n < Qualty Standards for Surface Water Envronment> (GB ), and the water polluton of Three Fors Lae, we select 9 tems as parameters, whch are

4 514 Wang Ke et al. / Proceda Envronmental Scences 10 ( 011 ) PH, H3-, total phosphorus, total ntrogen, permanganate ndex, transparency, TDS DO, conductvty. 4.. Observaton Pont Selecton. The nber of samplng ponts s lmted due to the geographcal problem n tang samples and the cost. We have studed the local water envronment, set 16 representatve ponts as observaton ponts, and dscretze Three Fors Lae geographcally, usng 18 ponts( Fgure 1)to represent water qualty of the lae. ow that the 16 observaton ponts are nown, we can calculate the value of 18 ponts resortng to the value of 16 ponts by means of Inverse Dstance-weghted Interpolaton. Fgure 1 the dstrbuton of water flows n Three Fors Lae;Fgure Representatve Ponts 4.3. Cluster Evaluaton. There are two ways to montor water qualty, aerospace hyper-spectral remote sensng mage and montor equpment placed n tested water. We gan relatve data from the montorng results.( Table 1) Table1 Actual Data of Measurng 16 Sectons n Three Fors Lae o. Lattud e Longtu de PH H3- Phosph orus troge n Perman ganate Index transpar ency (m) TDS DO Conduc tvty

5 Wang Ke et al. / Proceda Envronmental Scences 10 ( 011 ) We need to standardze orgnal data wth the followng formula n that the dmenson for testng s dfferent, and the data dffer greatly. Durng the process of standardzng all the data, we should untze the type of data. Therefore we utlze varous approaches to transform dfferent types of data nto the standard one.( The data process related to water qualty of Three Fors Lae s not consdered for water qualty here s havng PH greater than 7 and the data dfference s not obvous.) Table Reference Fgure for Contamnaton n Surface Water Envronment ame Type Refere nce Fgure S H3- Phosphorus trogen Perma nganate Index Transp arency (m) Mnm TDS DO Mnm Condu ctvty And the transform formula of dfferent style standard And the transformaton formula of dfferent classfcaton ndexes s as follows (whch S s a reference value of surface water pollutants, specfcally Table, for a measured pollutant concentraton): 1f the ndex s mn, then S x C f the ndex s max, then C x S Table 3 shows the standardzed results of the examnatons of pollutants. Table1 3 Actual Data of 16 Measured Sectons n Three Fors Lae o. Lattud e Longt ude PH(1) H3- () Phosp horus( 3) trog en(4) Perma nganat e Index( 5) Transp arency (6) TDS(7 ) DO(8)

6 516 Wang Ke et al. / Proceda Envronmental Scences 10 ( 011 ) Classfy the data wth the Ward method, and then use the toolbox of Classfy n SPSS to analyze the standardzed data of the 16 actual measured sectonal ones Fg. 3 fnal results of 16 sectonal cluster ;Fg. 4 cluster chart of polluton factors 1) Cluster accordng to cases From Fgure 3, Observaton ponts 10, 1 and 15 belong to the same type and the rest belong to the other type. Wth the water dstrbuton n Fgure 1 beng consdered, the concluson s drawn out that the three ponts 10,1,15 whch belong to the rver branches where the water s less and closer to the nland are more serously polluted. ) cluster through the polluton ndces The major ndexes of polluton n Three Fors Lae are Index 1, Index, Index 5 and Index 8, whch respectvely refer to ammona, total phosphorus, degree of transparency and electrcal conductvty. Transparency and electrcal conductvty are manly nfluenced by ol and mnerals. Wthout any factores nearby, Three Fors Lae s free from ndustral dscharge, therefore the major causes of polluton s from the cage breedng of fsh and household garbages. 3) Interpolaton

7 Wang Ke et al. / Proceda Envronmental Scences 10 ( 011 ) About the general stuaton of water qualty of Three Fors Lae, the author means the method of weghted nterpolaton by nverse dstance. From the observaton ponts from 16 out of 18 ponts, the general stuaton of water polluton can be fgured out as n Fgure, n whch pont "*" s used to calculate the value of pont "o". Frst, treat the lattude and longtude of pont "o" as the coordnates of the nterpolaton pont. Second, the value of feature parameters of the water qualty can be drawn out wth the help of formula (.3). Smlarly, wth the method of herarchcal cluster of the analyss 18 water qualty nformaton, t s conclude that the branches where observaton ponts 10, 1, 15 are set s more serously polluted than the other branches. In smary, the envronment n Three Fors lae has been gradually polluted, and the polluton of envronment n branches where pont 10, 1 and 15 were set has been n level [6]. owadays, the government has taen more measures to control the cage breedng n ths area. Those people s dea of protectng the envronment has been mproved and some equpments of breedng have gradually been removed. Concluson Through a analyss of the followng 9 parameters, whch are PH, H3-, total phosphorus, total ntrogen, permanganate ndex, transparency, TDSDO, and conductvty, the water qualty n Three Fors Lae has been objectvely estmated wth the combnaton of the Cluster analyss and the method of Inverse Dstance-weghted Interpolaton. Ths provdes foundatons for the future plan and the contnuous development. However, the latter method mght be nfluenced by the local geographcal stuatons and the nber of observaton ponts, and the concluson can only partally reflect the real stuaton of the lae. Many dscussons on ths ssue stll need to be carred on References [1]Wu Chang Guan etc. Spatal Interpolaton Methods and Temporal-Spatal Dstrbuton of Precptaon n the Three Gorges Reservor AreaResources and Envronment n the Yangtze Basn010, []WenRu YangApplcaton of nverse dstance weghted n terpolaton method n contam nated ste assessment,chnese Journal of Appled Ecology,Sep,007,18(9): [3]Kang aanalyss of Regonal Polluton Process and Applcaton of System Cluster MethodResearch of Envronmental Scences0ct.009,(10) [4] Envronmental Assessment on General Plan for the Frst Stage at Three Fors Lae Cooperaton Zone [5] Three Fors Lae n Janyang Cty, [6] The Qualty of Surface Water of January, 011 n Schuan Provnce,