Accessing the Impact of Floating Houses on Water Quality in Tonle Sap Lake, Cambodia

May Phue Wai,Khy Eam Eang,Rina Heu,Rattana Chhin,Vibol Chem,Sokly Siev

doi:10.3390/su14052747

Abstract

The floating houses in Tonle Sap Lake might be one of the main factors for degradation of water quality since the people in floating houses discharge sewage and waste from their households into the lake. Therefore, the government of Cambodia has decided to move the floating houses in Chhnok Tru to the upland regions, and more than 90% of the floating houses in Chhnok Tru have already been moved in accordance with the government’s plan. However, the scientific information on water quality before and after moving the floating houses in Tonle Sap Lake is limited. Thus, this paper aimed to evaluate differences in basic water quality such as temperature, pH, dissolved oxygen (DO), oxidation–reduction potential (ORP), conductivity (Cond), and nitrate (NO3−) before and after the floating houses were moved and to reveal the relationships between the floating houses and basic water quality. The water quality parameters were measured at 18 sampling sites in Chhnok Tru using an EXO sensor and NO3− was analyzed by ion chromatography (IC). Statistical analyses such as t-tests, correlation analysis, principal component analysis (PCA), and structural equation modeling (SEM) were used. The results show that the water quality was better after moving the floating houses; however, some parts of the study area were still polluted. In addition, the percentage of floating house distribution was significantly correlated with the temperature and ORP in the study area during dry and wet seasons. The obtained results are useful for making management decisions to sustainably manage the water quality in the area.

Highlights

The ecosystems of the lakes, the health of the livelihoods of communities, and the impacts on the economy depend on the water quality of lakes [1,2]
The box plots show that the temperature trend before moving the floating houses in both the dry and the wet seasons was increasing
An increase in temperature leads to an increase in the reaction rate of chemicals in water, and dissolved oxygen decreases in water [23]

Summary

Introduction

The ecosystems of the lakes, the health of the livelihoods of communities, and the impacts on the economy depend on the water quality of lakes [1,2]. When evaluating the sustainable development of a region, water quality is one of the most important factors to consider [3]. Given the importance of water quality, the assessment of water quality in lakes has become important [4–6]. Tonle Sap Lake (TSL), the largest freshwater lake in Southeast Asia, is critical for the socioeconomic conditions of Cambodian communities [7,8]. The area of the lake is approximately 2500 km , with the depth of the lake less than 1 m during dry season. In the wet reason, the lake becomes about 15,000 km , with a depth of 7–9 m [9]

Objectives

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Conclusion