APPLICATION OF WEAP MODEL IN FORECASTING WATERQUALITY FOR WATER RESOURCES PROTECTION MASTER PLAN WITH PILOT STUDY IN DAY RIVER BASIN
Thuan D. NGUYEN1, Sinh T. DO1, Hang T.TRAN1, Anh T.T. LE2, Duong D. BUI1,*
1 National Center for Water Resources Planning and Investigation
2 Centre for Environmental Fluid Dynamics, Hanoi University of Science, VNU
ABSTRACT
During the last few years, along with socio-economic development, water quality issues have also risen. Thus, water quality change trend forecasting have an important role in supporting water resource managing and planning in particular as well as socio-economic planning in general. In order to solve these issues, this study proposed WEAP model to support managers, planners in suggesting optimized scenarios for sustainable water resources management. The report includes: analyzing the advantages, disadvantages of the model, and the applicability of the model in Vietnam and then conducting a pilot study on mainstream of Day river (from Day estuary to the end of Ha Nam province) with the trend forecasting of water resource quality changes for 04 parameters (BOD, COD, DO, TSS) based on the scenarios to control discharged sources as well as the purpose of water resources exploitation. The results of this study indicated that the model is perfectly suitable in the conditions of Vietnam.
1. INTRODUCTION
Water resource master plan is the urgent mission in the current stage. The Resolution No. 24-NQ/TW dated 03/6/2013 of the 7th plenum of the Party Central Executive Board XI on actively responding to climate change, enhancing resource management and environmental protection has identified specific tasks on resource management as "rational, effective and sustainable planning, management, exploitation and use of national resources" in which "the master plan of water resources exploitation and protection, and the enhancement of water resources management” are the focal tasks.
However in recent years, along with the socio-economic development, the increase of population, the urbanization processes lead to the increase in the water demand for the population and production resulting in the negative impacts to environment and water resources. In many water basins, the pollution is getting more and more serious, affecting the production of community. Typically, there are a number example of polluted river basins such as Dong Nai river - Saigon, Cau river, Day river (National Environmental Report 2006).
Day river basin has an important role in the economic development of the country in general and the Red River Delta region in particular. Basin has an area of 7665 km2, representing 10% of the total area of the Red River basin, located in the five provinces of Hoa Binh, Hanoi, Ha Nam, Nam Dinh and Ninh Binh (report on Nhue - Day basin, Water Resources Management Department, 2007). According to statistics in December 2010, the total population of the provinces, cities located in the river basin was approximately 8.2 million people, the average population density was about 1,115 persons / km2 with 4.24 times higher compared with the national average (263 people / km2).
According to the analysis of water quality in 2009 - 2012 at some location on Day river, water was contaminated locally at some residential waste water receiving points of 2 living areas along river banks, which has not met the water quality standard of QCVN 08/2008 BTNMT type A1 (Technical Regulations on the quality of surface water for drinking water supply). Some sections were most seriously polluted stretch from the Mai Linh Bridge to Ba Tha Bridge. Due to the affects from Hanoi wastewater, the pollution levels are very high; at downstream segment, water quality has improved but still has not reached the standard of type B1. Pollution in Day river is mainly localized in some areas through residential areas, industrial parks due to the receiving of large waste sources.
WEAP is an effective tool for planning and management of water resources. It is used to simulate rainfall, basic flow, analyze water demand by sectors, protect water resources, priority allocation of water resources, operation of reservoirs, power generation, pollution and water quality monitoring. The model has been applied popular as of the moment, regarding the application model WEAP in countries around the world, there are over 30 projects evaluated water resources in most countries continents including the USA, China, Thailand, India, Mexico, Brazil, Germany, South Korea, Ghana, Kenya, South Africa, Egypt, Israel and Oman.
The model can be applied well in the condition of data availability in the basin of Day River. Thus, the application of the model to predict the variation of water quality in the basin of Day River is suitable. The result of the study is an important research serving the planning of water resources protection.
2. RESEARCH METHODOLOGY AND DATA USED
2.1 Methodology
There have been many studies to evaluate trends in water quality changes, the majority of them use statistical methods and mathematical models. In this study we present some results of forecasting on changes trend in the water quality in the mainstream of Day River under the impact of the point source waste by using mathematical models (WEAP model). The calculated diagram is shown in Figure 1.
Figure 1. Approach diagram
