Wetland Digitization and Inventory

Wetland Digitization and Inventory

Definition (Mitsch and Gosselink 2007):

A ‘wetland Inventory’ may be defined as: “the determination of the location and extent of wetlands”

Definition (Ramsar 2005):

“ The compilation of data about a wetland’s main biophysical features namely: soil, geology, surface area, water regime and water chemistry etc as well as management features such as land use, goods and services.”

Type of Information required:

Objective/s of the inventory

Wetland definition

Classification systems used

Method/s of data collection

INTRODUCTION

Wetland Classification:

Analysis of land use map series of Mauritius

Analysis of the Ramsar Wetland Classification Scheme and Regional wetland classification systems such as that used in the Southern African Development Community (SADC)

Landscape Unit approach used by Dugan (1990)

Wetland Digitization:

Land use map series at 1: 25,000 scale (GOM-OS 1991)

Classification units

ArcGIS™ software

METHODOLOGY

Collection of wetland attributes’ data:

Wetland names

Wetland classification

Soil maps

Underlying geology

Climate

Mean elevation

Surface area

Geographic location

Methodology (Cntd)

RESULTS

Wetland Classification:

Eight (8) ecological units were defined:

Marine coasts

Estuarine

Floodplains

Marsh/Swamp

Lacustrine

Depressions

Mangroves

Reservoirs

Results (Cntd)

Wetland Digitization: 129 wetland polygons and 144 point features

Ecological units

SurfaceArea of polygons (km2)

Distribution of ecological units point features per region

N NW E SE S SW W CPL CPW

Marine coasts 1.18 2 nil nil 3 nil 1 nil nil nil

Estuarine 0.95 2 2 2 7 3 1 5 nil nil

Floodplains 1.38 3 nil 3 1 1 1 4 nil nil

Marsh/Swamp 2.03 17 nil 22 7 1 nil 1 2 2

Lacustrine 0.13 nil nil nil nil 2 nil nil nil nil

Depressions 0.24 2 1 7 1 7 3 2 2 2

Mangroves 1.17 4 nil 9 3 nil nil nil nil nil

Reservoirs 11.95 1 nil nil nil nil nil 1 4 2

Total 19.03 31 3 44 22 14 6 15 8 6

Results (cntd)

Wetland Attribute Table (129 wetland polygons)No Id Wetland name Region Mean

elevation (m)2d.p.

Surface area(km2) 3d.p.

Underlying Geology

Soil type

Climate type

1 Id1 BBMP SE 0.36 0.847 N/A N/A SB

2 Id1 Le Bouchon SE 0.00 0.142 DL3 N/A H

3 Id1 Bassin Bernard N 0.00 0.086 N/A N/A SP

4 Id1 Le Morne SW 1.15 0.063 BTP C H

5 Id1 Mudflat SE 1.52 0.038 DL1 M H

6 Id1 Bassin Goemons N 0.00 0.004 N/A N/A H

7 Id2 RTREBS NW 0.00 0.266 N/A N/A SB

8 Id2 RChampagne1 SE 0.30 0.127 DI1 H/S H





13Id2

RChampagne6 SE 4.04 0.143 DI1 H/S H

14 Id3 St Martin S 3.25 0.161 BTP L H

15 Id3 La Prairie SW 3.95 0.316 S1 C H

16 Id3 Mare Piram N 25.56 0.121 DI2 G SB

17 Id3 Wolmar1 W 1.99 0.089 S1 C SB

18 Id3 Wolmar2 W 4.39 0.115 S1 C SB

19 Id3 Wolmar3 W 5.06 0.051 S1 C SB

20 Id3 Wolmar4 W 1.71 0.115 S1 C SB

21 Id3 Le souffleur SE 5.04 0.017 DL1 C H

22 Id3 Clemencia E 86.96 0.081 DL2 LG SP

23 Id3 Camp de Masque E 82.78 0.061 DL2 I SP

24 Id3 La Lucie E 67.93 0.035 DL2 I SP

25 Id3 Mare Grand Maree N 15.08 0.172 DI2 L SB

26 Id3 Mare Pont Malette N 18.43 0.044 DI2 L SB

27 Id4 Choisy Barachois E 2.97 0.014 DL3 T H

28 Id4 Mare Rond E 4.92 0.042 DL2 C H

29 Id4 Mare de la Montagne Gourmande E 4.94 0.040 S1 C H

30 Id4 Mare Casse Ghoon E 7.51 0.063 DL2 T H

31 Id4 Mare Blanche E 8.13 0.036 DL2 T H

32 Id4 Mare du Verger E 6.91 0.029 DL2 T H

33 Id4 Mare du Puits E 6.32 0.120 DL2 T H

34 Id4 Mare Planche E 9.94 0.018 DL2 T H

35 Id4 Mare Laurent E 2.43 0.022 DL2 C H

36 Id4 Mare Chevrette E 7.54 0.070 DL2 T H

37 Id4 Mare- aux- Anguilles E 8.27 0.055 DL2 T H

38 Id4 Solitude N 29.52 0.015 DI2 G SB

39 Id4 Mare Michaux N 2.46 0.032 DL2 T SB

40 Id4 Grande Mare Longue N 4.01 0.135 DL2 T SB

41 Id4 Mare Camp Pave N 4.32 0.060 DL2 T SB

42 Id4 Mare Millet1 SE 3.61 0.006 DL1 P H

43 Id4 Mare Millet2 SE 5.68 0.021 DL1 P H

44 Id4 Mare Dodo1 SE 9.09 0.007 DL1 P H

45 Id4 Mare Dodo2 SE 6.94 0.023 DL1 P H

46 Id4 Providence wetland E 3.70 0.114 DL2 T H

47 Id4 Mare Sottise N 7.32 0.009 DL2 T SB

48 Id4 Mare Soyfoo N 5.15 0.022 DL2 T SB

49 Id4 Mare aux Trois Ilots E 7.85 0.090 DL2 T H

50 Id4 Palmar wetland E 7.07 0.017 DL2 T H

51 Id4 Cap Malheureux wetland N 6.08 0.030 DL2 T SB

52 Id4 Pte de Roche Noir wetland E 4.87 0.056 S1 T H

53 Id4 Mare Tatos E 8.43 0.048 DL2 T H

54 Id4 Mare aux Lubines E 6.93 0.012 DL2 P H

55 Id4 Dagotiere CPL 443.82 0.182 DL1 B SP

56 Id4 Mare Samson W 4.88 0.024 S1 C SB

57 Id4 Anse Du Bain1 N 9.26 0.006 DL1 P H

58 Id4 Anse Du Bain2 N 6.18 0.008 DL1 P H

59 Id4 Pointe des Lascars N 9.64 0.024 DL1 P H

60 Id4 Pte Oscorne N 8.45 0.015 DL2 T SB

61 Id4 Grand Barachois N 5.34 0.012 DL2 I SB

62 Id4 Pte Radeau E 1.91 0.009 S1 T H

63 Id4 Beau Vallon 1 SE 7.45 0.047 DL1 I H



66 Id4 Mare Phedre1 N 5.72 0.144 DL2 T SB



69 Id4 Grand Baie 1 N 5.97 0.006 DL2 T SB

70 Id4 Grand Baie 2 N 7.11 0.004 DL2 T SB

71 Id4 Grand Baie wetland3 N 2.93 0.033 DL2 T SB

72 Id4 GBassinS

666.43 0.011 DL3 M SP

73 Id4 Mare Sarcelle1 E 3.39 0.199 DL3 T H

74 Id4 Mare Sarcelle2 E 3.54 0.032 DL3 T H

75 Id4 Bar le Duc CPL 469.23 0.009 DI4 I SP

76 Id4 Wetland B E 2.79 0.006 DL3 T H

77 Id5 Grand Bassin S 655.24 0.090 DL3 M SP

78 Id5 Bassin Blanc S 461.97 0.039 DL3 T SP

79 Id6 Wetland A N 8.11 0.012 DL2 P SB

80Id6

Bassin Oozeerally E 1.19 0.008 DL2 T H

81Id6

pond7 E 2.32 0.006 DL3 T H

82 Id6 pond8 E 4.16 0.004 DL3 T H

83Id6

Bassin Rivaltz E 3.09 0.016 DL2 T H

84Id6

Bassin Nozaic E 0.00 0.023 DL2 T H

85Id6

Bassin Requins E 5.68 0.018 DL2 T H

86Id6

Bassin Turmet E 3.41 0.006 DL2 T H

87Id6

Bassin Goemons N 3.27 0.003 DL2 I H

88Id6

Vallee des Pretes pond NW 23.23 0.014 BTP D SB

89Id6

La Crete pond SW 284.28 0.005 BTP M SP

90Id6

Chamarel SW 303.36 0.018 BTP M SP

91Id6

Mapou pond SE 138.39 0.007 DI1 M SP

92Id6

pond9 E 6.92 0.004 DL3 P H

93Id6

Rivulet Ruche S 254.19 0.018 BP T/S SP

94 Id6 Ruche pond S 290.41 0.006 BP T/S SP

95 Id6 Cresson pond2 S 12.40 0.004 DI3 M H

96 Id6 Cresson pond1 S 17.96 0.003 DI3 M H

97 Id6 Michel pond S 78.23 0.003 DI3 M H

98 Id6 La Dagotiere CPL 444.72 0.021 DI3 I SP

99 Id6 Alma pond CPL 450.00 0.011 DI3 LG SP

100 Id6 pond1 S 28.61 0.004 DI2 I H

101 Id6 pond2 S 106.01 0.006 DI2 M H

102 Id6 pond3 S 25.61 0.010 DI2 I H

103 Id6 pond4 S 308.56 0.005 DI3 M H

104 Id6 pond5 S 54.13 0.004 DI2 I H

105 Id6 pond6 S 84.95 0.006 DI2 I H

106 Id7 Pte Corail SE 0.73 0.049 BTP S H

107 Id7 Pte D'Esny SE 1.84 0.110 DL1 C H

108 Id7 Bras de Mer mangrove E 1.38 0.029 DL3 T H

109 Id7 Trou Mano mangrove E 0.00 0.036 DI4 I H

110 Id7 Mangrove Roches Noires E 3.56 0.018 DL2 T SB

111 Id7 Mangrove1 N 0.37 0.024 DL1 I SB

112 Id7 Mangrove2 E 0.18 0.017 DL1 M SB

113 Id7 Mangrove3 N 0.11 0.011 DL2 M SB

114 Id7 Mangrove4 N 0.00 0.016 DL1 M SB

115 Id7 Mangrove5 E 0.39 0.051 DL2 I SB

116 Id7 Mangrove6 E 0.50 0.034 DL2 I H




120 Id7 Mangrove10 E 0.56 0.007 DL2 S H

121 Id7 Mangrove11 SE 0.10 0.013 DL1 S H

122 Id8Eau Bleu CPW

348.59 0.681 DL1/BTP I SP

123 Id8Piton du Milieu CPW

428.17 0.610 DI2 M SP

124 Id8Valetta CPL

446.82 0.734 DI1/DI2/DI3 M/I/LG SP

125 Id8La Nicoliere N

243.67 1.030 BTP/DI2 M/T/S SP

126 Id8La Ferme W

142.62 2.232 DI4 I/D/T SB

127 Id8 Mare-aux-Vacoas CPL 559.11 5.106 DI4 M/I SP

128 Id8 Tamarind Falls CPL 485.18 0.567 BP M SP

129 Id8 Mare Longue CPL 565.30 0.990 BP M SP

CONCLUSIONS

Total surface area of 129 digitized wetland polygons = 18.35 km2,

S.A. of inland natural wetlands = 7.08 km2 ~ 0.38% of total S.A. of Mauritius,

Marsh/Swamp ecological unit most widely distributed (50),

Most wetlands are situated in the North, East and South- East of the Island,

GIS, primary tool in the digitization and collection of wetland attributes data,

GIS wetland database may be used as a platform for addition of more accurate data,

Proper conservation and protection measures are required to preserve the ecological integrity of wetlands and stop their destruction.

Documents

Wetland Digitization and Inventory