RDE Activities
Completed - ERDB Coastal Zone and Freshwater

Project/Study TitleLandscape approach to river ecosystem assessment and water classification
Date Started
Date Completed
Place of Implementation 
Region 3, Region 4 
Funding Agency 
Study Leader: Antonio M. Daño
1. Assess the physical characteristics and water quality of selected river systems as influenced by the different land uses;

2. Determine the consumptive and non-consumptive use of the selected river systems; and

3. Identify critical parameters as inputs for the ecosystem health assessment and classification of river systems.
A research study was undertaken to assess the water quality and classify the river based on landscape approach. More specifically, the objectives were to study the water quality characteristics of the river system as affected by the various land uses in the landscape; determine the consumptive and non-consumptive use of the river system; and determine the parameters for ecosystem health assessment of the river.

Lian-Palico River, which traverses from Cavite down to Nasugbu Bay in Batangas and Tanay River were zoned into upper, middle and lower reach for assessment. Lian-Palico River and Tanay River have a drainage area of about 18,590 and 5,344 hectares, respectively. The two river systems both belong to Climatic Type 1. The forest vegetation of Lian-Palico consists mostly of secondary growth forest in steep slopes of Mt. Batulao and Mt. Talamitam. Sugarcane is the most dominant annual crop. The presence of sugar mills makes this crop a major crop in the watershed. Forest vegetation in Tanay watershed consists mostly of secondary growth forest. Open/brushland consists mostly of cogon and akleng parang. Cultivated lands are planted with coconut, mango and other fruit trees and cash crops.

The upper and middle part reaches of Lian-Palico River have high level of total and fecal coliform as well as high concentration of phosphate. The lower reach have high level of BOD, low in dissolved oxygen (DO), high in total coliform and phosphate. High coliform level was attributed to piggery farms and from livestock grazing in the watershed. Low level of dissolved oxygen in the lower reach is quite alarming. Leachates from decaying garbage and domestic/household wastes from the residents as well as industrial waste could be contributed to this high BOD and phosphate levels. The upper to lower reaches of Tanay River also showed very high level of total and fecal coliform. Walk through survey showed that the piggery farms discharging their wastes to the river is the possible cause of the high level of coliform. In lower reach, dumping of solid waste contributed to the high coliform and foul smell of the river.

Modified water quality index proved reliable in assessing the health of the river systems. The lower reach of Lian-Palico River was found to be in a very bad state while the middle reach borders in critical state indicating that serious measures have to be implemented to avoid getting into bad condition. On the other hand, the very bad state of the lower reach signals that anytime disasters like fish kill can occur along the stretch of the river. Tanay River, on the other hand, was found to be in medium state bordering from good to bad state. The high fecal coliform content and BOD contributed to its current health condition.

Aquatic macro-invertebrates are important indicators of the health of the river system. Stoneflies (Plecoptera) could hardly be found. Absence of this insect is indicative of the high concentration of nitrogen or phosphorus in the system. Decreasing dominance of mayflies from upstream to downstream portion of the river was also observed. Some Ephemeroptera and caddiesflies (Tricoptera) were found sensitive to pollution while others are highly tolerant. In the case of Ephemeroptera, the family Heptageniidae seems to be a good indicator of organic pollution. Order level classification of insect is less reliable in determining indicator species of the health of the system.

It is recommended that the condition of the river be included in the classification of our rivers. Classification should consider separately the condition of the upper, middle and lower reach of the river. Two systems can be considered - a) incorporate the health of the river and the problems in the river to the present classification system; and 2) revise the current system and use the health status of the river system. Further study on the use of aquatic macro-invertebrates particularly at the species level and the active role of LGUs in the management of water resources under the 2004 Clean Water Act were also recommended.
For more information, please feel free to contact us through the
'CONTACT US' link above, or, through the contact details given below this page.