QUALITY ASSESSMENT OF SEA LEVEL DATA by the UH SEA LEVEL CENTER/NATIONAL OCEANOGRAPHIC DATA CENTER JOINT ARCHIVE FOR SEA LEVEL updated: 28 Feb 2005 Station : Hiron Point Latitude: 21 47.0N Country : Bangladesh Longitude: 089 28.0E JASL # : 134A Time Meridian: 090E (GMT + 6 hr) GLOSS # : none Originator #: 110 NODC #: 12081901 Contributor : Bangladesh Inland Water Transport Authority (BIWTA) Dept. of Hydrography 141-143, Motijheel C/A Dhaka - 1000 BANGLADESH Originator : same Original Data: analog Instrmnt Type: float and well type gauge (Munro) Digitzd Intvl: hourly Present Data : Hourly, daily, and monthly values obtained by: Hourly : original data are hourly Daily : 119-point convolution filter (Bloomfield, 1976) centered on noon applied to the hourly data with respective periods of the 95, 50, and 5% amplitude points at 124.0, 60.2, and 40.2 hours Monthly: Simple average of all daily values; calculated if 7 or fewer days are missing Span of data : 16 Jan 1977 - 31 Dec 2003 Gaps > 1 mon : none Time Refernce: GMT (hours 00-23) Space-filler Flag :-9999 Units : millimeters Missing Data Flag : 9999 Existing : Yes Operational : Yes Sat. Trans. : No Distribution : 1977-2003 Refernce Levl: The sea level heights are referred to the zero point assigned to the tide staff. Bench mark information is available upon request from BIWTA. Level shifts were identified in the series and adjusted as follows for a short time segment: value added period (hour)day/month/year to original(mm) ----------------------------- --------------- (18)31/10/1982-(16)31/12/1982 430 This adjustment is uncertain to a few cm. Comment : The daily and monthly means do not reveal any reference level shifts or trends. There are some abrupt level changes but these appear to be natural signals. The most abrupt is on 06 March 1999. This feature is suspicious. Otherwise, the data are of good quality. Numerous short gaps were interpolated during July-August 1977. Occassional minor timing drifts occurred throughout the record. CI MISSING REPLACED GAPS QUESTIONABLE YEAR (%) DATA OR BAD DATA FLUCTUATIONS ---- --- -------------------- --------------- -------------------- 1977 96 151-152 (08)156-(01)157 122-125,137-140,152- (13)178-(23)178 154 (13)179-(23)179 (13)180-(00)181 (13)181-(23)181 (13)182-(23)182 (13)183-(00)184 (12)184-(23)184 (08)185-(23)185 (13)186-(23)186 (13)187-(23)187 (13)188-(23)188 (13)189-(23)189 (13)190-(23)190 (13)191-(23)191 (13)192-(23)192 (12)193-(23)193 (13)194-(23)194 (13)195-(23)195 (13)196-(23)196 (13)197-(23)197 (13)198-(00)199 (13)199-(23)199 (13)200-(23)200 (13)201-(23)201 (13)202-(23)202 (13)203-(23)203 (12)204-(23)204 (12)205-(23)205 (12)206-(23)206 (13)207-(00)208 (13)208-(00)209 (13)209-(23)209 (12)210-(00)211 (12)211-(00)212 (13)212-(23)212 (13)213-(00)214 (13)214-(23)214 (13)215-(23)215 (13)216-(00)217 (13)217-(23)217 (13)218-(23)218 (13)219-(00)220 (13)220-(23)220 (13)221-(23)221 (13)222-(23)222 (13)223-(23)223 (13)224-(23)224 (13)225-(00)226 (12)226-(23)226 (12)227-(23)227 (15)284-(23)284 1978 100 none (15)239-(01)240 none (14)242-(03)243 (13)257-(01)258 (21)263-(09)264 (19)283-(07)284 (06)298-(22)298 1979 98 44-45,325-330, (14)105-(02)106 160-165 352-353 (03)183-(01)184 (13)201-(01)202 (05)234-(03)235 (04)239-(03)240 (05)286-(03)287 1980 96 9-11,166-175,265- (11)022-(04)023 none 267,357-360 (12)035-(00)036 (11)036-(01)037 (13)037-(01)038 (13)038-(00)039 (15)138-(22)138 (08)335-(17)335 1981 99 52-54,107-108,179- none none 181 1982 99 52-53,313-314 (09)304-(20)304 none 1983 100 none (19)155-(05)156 77-82,323 (21)156-(06)157 (21)157-(06)158 1984 99 159-160 (08)051-(16)051 none (05)285-(04)286 1985 100 none (13)137-(21)137 none (05)265-(18)265 1986 100 none none none 1987 99 321-324 (21)161-(17)162 119-120,123 1988 99 244-245 (07)265-(01)266 55 1989 99 198-199,200-201 (06)038-(17)038 93-97 (08)100-(06)101 (11)211-(18)211 (16)218-(23)218 (15)219-(23)219 1990 99 126-129 none none 1991 100 none none none 1992 100 none none none 1993 98 195-202 none none 1994 100 none none none 1995 97 104-113,323-325 none none 1996 100 none (18)104-(17)105 none 1997 100 none none none 1998 100 none (00)243-(17)243 none 1999 95 38-54 (08)036-(17)036 none (07)037-(17)037 (10)209-(17)209 2000 100 none none 321-326 2001 99 332-334 (08)183-(22)183 none 2002 99 305-307 (18)315-(02)316 none 2003 99 365 none none