Janice Lynn Ayog

COMPARISON OF GEV AND GUMBLE’S DISTRIBUTION FOR DEVELOPMENT OF INTENSITY DURATION FREQUENCY CURVE FOR FLOOD PRONE AREA IN SABAH

Rainfall data has a significant role in hydrological design which is, it’s produce the intensity duration frequency curve. IDF curve gives critical information that needed in the design of water management infrastructure, it gives information by showing the mathematical relation of rainfall intensity, recurrence interval of the storm and duration of storm. This paper aims to compares and develop IDF curve using two frequency distribution which is generalized extreme value distribution (GEV) and Gumbel distribution (EV1). Then, the best fit distribution for flood-prone area in Sabah will be choose and determined from the two-mentioned distribution. The goodness of fit test that used to determine the best distribution is chi-square test, it works by determining the differences between observe data value from Weibull formula and the estimated values from GEV and Gumbel’s distribution method. After that the chi-square value for GEV and Gumbel is compared to the critical value from chi-square table at significant level of 5%. From the Chi-square test, it is concluded that Gumbel’s (chi square value Tandek:0.47952, patiu:1.0531, babagon: 1.026931, Ulu Moyog:0.382415) shows a better fit distribution compared to GEV distribution (chi square value Tandek:59.7598, patiu:16.5746, babagon: 3.3555347, Ulu Moyog:22.1315)

Rainwater Availability Assessment for Tourism Development: A Case Study of Turtle Islands Park, Sabah

This study mainly focused on the rainwater availability assessment in Turtle Islands Park, Sabah, Malaysia. Consisting of three small islands, this marine park is home to two endangered turtle species – Green and Hawkbills turtles. This special feature of the islands attracts tourist around the world, thus increasing the demand of freshwater supply for tourism development in the marine park. However, due to the shortage of freshwater from the ground due to salinity intrusion, rainwater is seen to be an alternative in fulfilling the freshwater demand. To evaluate the source of freshwater in these islands, information is obtained from the main users of the water source, which are the Sabah Park officers, the approved tour operator on the islands and the security forces. The rainwater tanks available on the islands are calculated to assess the storing capacity of rainwater. The water demand was estimated by multiplying the number of visitors with the average water usage per visitor. With the existing water tanks, this study found that the Turtle Islands Park has the ability to store 414 m3 of rainwater in Selingaan island, 3.2 m3 in Gulisaan island, and 102.1 m3 in Bakkungan Kechil island. However, the monthly water demand of each island exceeds the existing storage tanks, hence it is proposed that the number of rainwater tanks be increased to harvest as much rainfall as possible for the use of the islands’ inhabitants.