Spatial Analysis of Human Activities Performed in Cheung Ek Inundated Lake, Cambodia

Abstract

Cheung Ek is an important lake for the livelihood of local communities through different functions, it acts as a wetland area to control flood waters and removes pollutants from Phnom Penh city. However, industrialization, urbanization and uncontrolled human occupation on the bank of the lake has decreased the lake’s surface and caused the lake to become incapable of the evacuation and retention of storm water under the conditions of heavy rain. Global Positioning System (GPS) mapping was undertaken to analyze the lake border, water spinach and water mimosa surfaces and other human activities while other surveys were conducted to understand the method of cultivation and yield estimation of the main aquatic vegetables. The surface area of Cheung Ek Lake in the dry season is 992 ha and more than 50% of the area is occupied by human activities: 429 ha of water spinach; 32 ha of water mimosa; 13.5 ha of dry season rice field; 10-20 ha of fishing activities and around 10 ha of duck raising. In Cheung Ek Lake, water spinach and water mimosa are grown in rows secured by strings between the poles to prevent the crop from floating away. During the dry season, a water spinach cultivator can obtain an average yield of 16-17 tons/ha for a six-month production cycle while a water mimosa producer obtains an average of 15.5-16 tons from a production area of 5000 m² during a five month production cycle. In conclusion, during the dry season, the lake provides from 6864-7293 tons of water spinach and 992-1024 tons of water mimosa for human consumption. However, aquatic vegetable production is also facing many problems particularly with insect damage and disease outbreaks during the production period.