Shirley J. David
The study made use of the first-order three-state Markov chain process to characterize rainfall occurrences. Light rainfall occurs when rainfall amount ranges from 0 - 2.5 mm, moderate rainfall with amount from 2.6 - 15 mm and 15.1 mm or more as heavy rainfall. Data on daily rainfall from seven synoptic stations considered. Factors such as year, month, station and episode (El Niño and La Niña events) were considered to analyze the estimated transition probabilities. To understand and explain the variability that might be inherent to the estimated transition probabilities analysis of variance, variance component analysis and the lag-correlation analysis were used.
The analysis of variance was used for the purpose of determining the significant factors that might explain the estimated transition probabilities. Significant factors were further subjected to variance component analysis. Lag correlation analysis was used to determine if there is a significant relationship between the estimated transition probabilities and the Lagged-Southern Oscillation Index, which was lagged up to eighteen months.
Based on the results of the analysis of variance using the generalized linear models (GLM) procedure of Statistical Analysis Software (SAS), it was noted that for light-to-light and heavy-to-heavy transitions the significant factors were month, station and episode whereas for the other transitions such as light-to-moderate, light-to-heavy, moderate-to-light, moderate-to-moderate, moderate-to-heavy, heavy-to-light, and heavy-to-moderate, month and station were found to be significant.
The estimates of the variance components revealed that the variance associated with the experimental errors are cosiderably larger than the estimated variances of the significant factors considered to have influenced the estimated transition probabilities.
The relationship between the Lagged-Southern Oscillation Index (SOI) and the estimated transition probabilities were determined using the Lag-correlation analysis. The results showed a weak correlation between the estimated transition probabilities and SOI of preceding years nor same year.
Gilda C. Borja, Jocelyn B. Balacuit
The general objective of this study is to combine the salient hydrologic and meteorological variables to derive new variables that would be useful in examining surface water supplies. It also aims to develop a climatology of water variability and demand to examine these for possible critical periods, when a deficit (demand is greater than storage) is expected to occur. Specifically, this study aims to predict long-range seasonal variation of rainfall and surface water supply in the Bicol Region.
The surface water supply in the Bicol Region, particularly the Bicol River Basin was examined for 36 years, 1960-1996. A hydrologic accounting system, using rainfall and temperature as inputs was used to derive variables such as Potential Evapotranspiration (PET), soil moisture and runoff. These were combined with the basic hydrologic variables (stream discharge and lake contents).
Annual and monthly rainfall during normal wet and dry years were calculated and plotted to derive the geographical rainfall variations in the study area. It was also used to combine with other basic variables to derive additional variables such as Delta, storage and demand.
Complete time-series climatologies for all variables were presented.
Venus R. Valdemoro
Rationale: Public weather forecasts and warnings are of no use unless they reach the public. The PAGASA is mandated to "mitigate or reduce the losses to life, property and the economy of the nation occasioned by typhoons, floods, droughts and other destructive weather disturbances". Weather and climate affect people's safety, livelihood and leisure activities. Timely and up-dated weather information can protect people, dictate what they wear, how, when and where they travel and help them decide what activities to pursue. The cooperation of all media partners is fundamental to the success of the weather public information and communication activities of PAGASA. Statement of the Problem: This study analyzed the PAGASA weather information dissemination system vis-a-vis issues and problems. Specifically, it sought answers to the ff. questions: 1.) What is the status of PAGASA's warning and forecasting system in terms of objective; organizational structure; personnel and facilities? 2.) To what extent do media personnel understand and use information on weather conditions and forecasts? 3.) How do the general public perceive PAGASA's weather information dissemination system in terms of: a.) Source of information on weather forecasts and warnings; b.) Types of media used in weather information dissemination; c.) Updatedness as to the time of dissemination; d.) Frequency of updates made on weather information dissemination 4.) Are there significant differences in the perception of PAGASA weather information dissemination by the general public grouped according to regions they represent? Research Design: The descriptive method was used in this study by gathering facts through survey questionnaire with the present situation, the prevailing condition, current practices, contemporary events, the characteristics of the groups of individual, their behavioral paterns, attributes and opinions. It is means to find out qualitatively and quantitatively existing condition or relationship practices that prevail, beliefs, processes that are going on effects that are being felt, or trends that are developing. Its goal is to predict and identify relationships among and between variables. It provides information that will serve as basis for improving the warning system and messages being issued by the PAGASA. Treatment of Data: The data were analyzed and treated statistically. The statistical measures used in the study were percentage, weighted, mean, ranking and chi-square. Findings: a.) The status of weather information dissemination system of PAGASA in terms objectives are clearly defined in the stated functions to attain the mandated functions. The organizational structure of PAGASA suggest that there are specific positions and levels with defined functions and job responsibilities. On personnel, both in training and educational attainment (technical and non-technical) PAGASA could boast of a very strong man component as revealed of their educational qualifications and the continuous in-house training and foreign assisted trainings. While, PAGASA is well equipped with the state-of-the-art equipment as attested by its admission for membership to the WMO, also it is continuously maintaining and upgrading its equipment. b.) The extend of understanding of media personnel reveals a "moderate" to a "Great Extent" of understanding and use of weather Information Dissemination system of PAGASA by the Media Personnel of that the Mediamen are able to carry on weather information dissemination of PAGASA. Perceptions of the General Public on PAGASA's Information Dissemination System. Three indicators of weather conditions were used namely fair weather, fine weather and stormy weather. Data show that media personnel have good grasp of information relating to weather conditions. Media personnel are not quite at home with information relating to weather systems. This is so because not all media practitioners were able to attend media seminar-workshop conducted by PAGASA where all of these weather systems affecting the country are discussed thoroughly. It appears that media personnel understand the meaning of public storm signals. Based on findings it would seem that the Media Personnel would need to further on their basic knowledge on the Weather Information Dissemination system. While their knowledge is interpreted as "great extent" from the following indicators like Public Storm Signals, Weather Conditions Stages of Tropical Cyclone, Weather Forecasts and Effects of the Typhoon and Parts of the Typhoon and Weather Systems is only moderate. As perceived by the respondents from Regions 2, 3, and 5 information about a typhoon are disseminated by PAGASA two days before the start of bad weather. On the other hand, they claimed that information is disseminated three days or more before the start of bad weather. Some said the information is disseminated only one day before the start of bad weather. Nobody claimed that they received information about a typhoon right on the day bad weather occurs. Data show that the respondents from Region 2, 3 and 5 get information about weather conditions from the radio, television, newspapers, from the local PAGASA Station, neighbors and friends and from local officials. The radio is the number one medium also because should there is power failure due to strong winds and other factors during the occurrence of strong typhoons radio could be battery-operated. Updatedness as to the time of dissemination. As to how early forecast about an approaching typhoon are disseminated to the public and how frequently updates about an on-going storm shows that the respondents from Region 2 generally receive information about an approaching tropical cyclone two days before the start of bad weather. The Differences in the Perceptions of Respondents on PAGASA's Weather Information Dissemination System When Grouped by Regions shows that statistically no significant differences were found in the perceptions of the respondents from Regions 2,3, and 5 on how early information about a typhoon is disseminated by PAGASA as revealed by the obtained chi square value 5.584. Significant differences were found among the perceptions of the respondents from the three regions with respect to the frequency of updates on the typhoon as revealed by the computed chi square value of 10.50 which exceeds the critical value of 9.488 at .05 level of significance.. Data show that people from Region 3 and 5 tend to get updates on the typhoon more frequently than those in Region 2 and this could be attributed to the distance from the main forecasting center which is located in Quezon City. Conclusions: a.) PAGASA recognized the role of media men in the realization of its stated objective and function. Through an accurate and timely weather information dissemination system, which could be interpreted in terms of efficiency and effectiveness, could create a positive image for PAGASA. Media personnel are generally well versed with information relating to weather conditions, forecasts, tropical cyclones, effects of the typhoons and public storm signals but they are less familiar with weather systems and parts of a typhoon. b.) It could be expected that PAGASA could be able to function effectively thus realizing its mandate. c.) It is within the capacity of PAGASA to attain the mandated functions since its personnel are generally equipped with the knowledge required in their jobs through their educational attainment, local and foreign trainings. d.) PAGASA is equipped with state of the art equipment and therefore PAGASA is capable of locating, tracking and forecasting any weather disturbance. e.) The general public are forewarned as revealed in this study and are familiar with the weather information dissemination system, and it is because even if the tropical cyclone is outside the Philippine Area of Responsibility, the PAGASA could properly locate the weather disturbance through the satellite receiving facilities. f.) There are no significant differences in the perceptions of the general public on the weather information dissemination system. Recommendations: a.) More up-to-date equipment for weather forecasting should be utilized by PAGASA and push for the implementation of the 6-year modernization plan of the agency. b.) Modification of PAGASA weather forecasting and warning system as to effectively counter the adverse effect of tropical cyclone and other disturbances; c.) Media people engaged in weather information dissemination must meet certain qualifications set by PAGASA itself in addition to requirements of attending in-service training and seminar done periodically. d.) Issuance/Release of updates on the development of tropical cyclone as the case may warrant giving importance to the threatened areas. e.) Observance of formal and professional coordination among agencies in weather information dissemination (both governmental and non-governmental organizations). f.) A possible evaluation of existing laws (P.D. 78 and R.A. 1190) and practices, to determine a more systematic and accurate weather information dissemination system is a must. g.) Further study on OCD and PIIAS (PAGASA) could be undertaken to clearly delineate functions and duties on weather information dissemination system of the country.