NITROGEN LOADING OF MERBOK RIVER, KEDAH

Wan Ruslan Ismail^1,2,  Mohd Nazrul Ibrahim¹, Mohd Kusyairi Mohd Zahir¹, Zullyadini A. Rahaman¹

1 HydroGeomorphology Research Group, Section of Geography, School of Humanities,

Universiti Sains Malaysia, 11800 Minden, Pulau Pinang, Malaysia

Tel: 604-6532853; Fax: 604-6563707; email: wruslan@usm.my

2 Centre for Global Sustainability Studies

Universiti Sains Malaysia, 11800 Minden, Pulau Pinang, Malaysia

Summary 

A study was conducted  from October 2011 to  February 2012  in the catchment of Gurun and Upper Merbok River with the purpose to determine nutrient loading in Merbok river catchment as aconsequences of development activities in that area. Result from our short study period in the Merbok river catchment revealed that the nutrients was in low concentrations at the upper segment but increased in concentration at the lower segment. The output of nitrite at segment 1 during sampling period was 48.8 tonnes with 96.9 %.  The output of nitrite at segment 2 was 289.4 tonnes (83.1%) and output at segment 3 which is represent the total output of  the whole catchment was 4325.6 tonnes. The amount of nitrite load removed from the catchment was 4036.2 tonnes (93.3%). For output of nitrate at segment 1 was 68.6 tonnes (88.9%) and the ouput at segment 2 was 570.7 tonnes (88%). The total output of nitrate was 7496.5 tonnes based on output of segment 3; Merbok. The output of ammonium nitrogen at segment 1 during sampling period was 23.9 tonnes with 99.7 %.  The output of ammonium nitrogen at segment 2 was 108.2 tonnes (77.9%) and output at segment 3 which is represent the total output of  the whole catchment was 2216.5 tonnes. The amount of ammonium nitrogen load removed from the catchment was 2108.3 tonnes (95.1%) (See Figure).

a) Nitrite loading

        

b) Nitrate loading

c) Ammoniacal Nitrogen loading

Figure 1. Nitrite, Nitrate and Ammonium nitrogen loading in the Merbok catchment. The black part is the downstream of Merbok river. Meanwhile, the blue is middle segment part  and the light blue part is the upper segment of Merbok River catchment.

Acknowledgement: Universiti Sains Malaysia for RU grant entitle "Land use and land cover changes in the Gurun and Upper Merbok River and the possible effect on euthrophication of Merbok Estuary, Kedah"  No: 1001/PHUMANITI/816229.