19 May 2016 | FL-2016-0001-SL | Ve rsion 2.2Mapping Flood Extent for Kelani Ganga River Basin and its surrounding using RISAT-1 Satellite imageryMap Pre pare d b y: Data Provid e d b y:

The d e piction and use of b ound arie s, ge ographic nam e s andre late d d ata shown in the se m aps are b ase d on the sourc e sthe y have b e e n d rawn from and q uote d . The se are ne ithe re rror-fre e nor d o the y im ply offic ial e nd orse m e nt or the positionof IW MI.

LegendDisaste r Im age : RISAT - 1 (ISRO)Date :18 May. 2016

Division Map! Citie s/Town

Road Stre am s

Fort

Bope

W aga

W e ke

Kotte

Dom pe

Ekala

Horana

Botale

Hirana

Lunawa

Angod a

Pugod aMakola

Mahara

HorapeRagam a

Y ogam a

Y agod aJa_Ela

Gam paha

GowinnaW ad d uwa

Kum b uke

Mille waKe sb e wa

Colom b o

Kottawa Pad ukka

Malwana Kosgam a

Uruwala

Ud upilaW attalaHe nd ala

Egaloya

Ere pola

W alpolaKand ana

Y akkalaUrapola

Se e d uwa

N aragala

Gonad uwa

Panad uraMunagam aGurugod a

MoratuwaMad apata Gonapola

KahawalaTalagala

Angulana

De hiwala

Diyagam a

Lab ugam aGod agam a

Panagod a

Hom agam a

ArangalaN uge god a

Base line Kad uwe la

Hanwe lla

Rad awana

Kapugod aDe katana

He ne gam a

Biyagam a

Ke laniya

Kad awata

Mahab age

De lm e lla

Id angod a

Kirie llaIngiriya

Ellawala

N apawala

De loluwa

Sitawaka

Batagam a

Make wita

Be m m ullaDaraluwa

Tihariya

W aharaka

Kotugod a

Kananwila

Mille niya

Ratm alana

Pinnawala

Talangam a Am b ulgam a

Kolonnawa

Halwatura

Te ppanawa

Kahawatta

N ugad and a

Ge tahe tta

Mald e niya

De hiowitaGurugalla

Pingom uwa

Gonaram b a

Im b ulgod a

Gane m ullaBatuwatta

Pe raland a Pad d awala

Pingom uwa

Dum b uluwa

Alub om ulla

Pokunuwita

Kahatud uwa

W e llawatta

Maharagam a

Cotta RoadN awagam uwa

Mapitigam aKaluaggala

Putupagala

W e liwe riya

HunupitiyaW anawasala

Talapitiya

Mitirigala

Ruwanwe lla

God age d ara

Pam unugam a

Ud ugam pola

W aturugam a

Be llapitiya

Paragastota

Band aragam a

Egod a UyanaKoralawe lla

Polgasowita

Piliyand ala

Mt. Lavinia

Kollupitiya

Aturugiriya

N arahe npita

Puwakpitiya

Am itirigala

Migahawatta

End e ram ulla

Sinhalagod a

Ehe liyagod a

Avissawe lla

Karawane llaY atiyantota

Anguruwe lla

Kirind iwe la

Attanagalla

Kind e lpitiya

Kahatapitiya

Hand apangod a

Slave Island

Ud awalakand a

Bulugahagod a

Kud ahakapolaKalage d ihe na

Bam b alapitiya

Borale sgam uwa

Mipe Junction

Uswe take iyawa

Gonagald e niya

W athupitiwala

Ud atuttiripitiya

Kalu Ganga

Kelani Ganga

Attanagalu Oya

Kalu Ganga

Ke lani Ganga

The re c e nt low pre ssure syste m in Ind ian Oc e an cause d he avy rainfall across Sri Lanka sinc e 14 May 2016 causingwid e spre ad flood ing and land slid e in as m any as 19 d istricts, includ ing around Colom b o. Ke lani Ganga is one of the m ainrive r b asin in Sri Lanka whic h is curre ntly e xpe rie nc ing large scale flood ing and sub se q ue nt d am age to prope rty andlive lihood s. Ke lani b asin re c e ive d 350 m m of total rainfall within thre e d ays (15 to 17 May 2016). The wate r le ve ls of Ke laniat Hanwe lla Gauge was 10 ft ye ste rd ay b ut re c e d e d to tod ay 9 ft. Most of the runoff contrib utions are from rainfall in theupstre am hilly are a of Sri Pad a m ountain range .IW MI re c e ive d sate llite im age ry from RISAT-1 d ate d 18 May 2016 through Inte rnational Disaste r Charte r (IDC) provid e b yInd ian Spac e Re se arc h Organization (ISRO). It is e stim ate d that the m axim um inund ation ob se rve d for 18 May 2016 isapproxim ate ly 2,343 sq . km . As m e ntione d e arlie r, m ost of this stand ing wate r are notic e d in ab and one d cropland s, b ananacultivations and large scale d e vastation in house hold are a as we ll as se ve ral road s have b e e n d isc onne cte d re stricting them ove m e nt of ge ne ral population.The curre nt flood ing e ve nt affe cte d 172,000 pe ople in and around Colom b o, 122,000 in Gam pha and 12,757 in Ke gallem ainly from land slid e re porte d on 18 May 2016. Six to te n fe e t of flood wate rs we re ob se rve d in som e house hold localitie scausing untold d am age to rural house hold s and gard e ns/cropland s. Are a und e r b anana cultivation and rub b e r plantations arealso curre ntly und e r stand ing wate r. The flood affe cte d Gram a N ilad hari (GN ) d ivisions inc lud e s: Kolonnawa GN D –W e llam pitiya, Ke lanim ulla, Gotatuwa, Ud um ulla N orth, and Kad uwe la_GN D – W alpola, Kad uwe la, Mahad e niya, Rangala,W e livita, Malab e W e st, Pahala Bom iriya, Ihala Bom iriya) and for the Gam paha GN d ivisions - Gam paha, Biyagam a,Dom pe , Jae la, Diulapitiya b ase d on the re ports from Disaste r Manage m e nt Ce nte r (DMC).

The analysis e xc lud e d pe rm ane ntwate r b od ie s inc lud ing re se rvoir,tanks and pond s and this re fle ctsonly the inund ation e xte nt. Ple asenote the surfac e wate r e xte ntm appe d has not ye t b e e n valid ate d

Kelani Ganga

Attanagalu Oya

Kalu Ganga

Basin