La Mesa Watershed

GCSE Geography

Michael Diamond

February 27, 2009

Block F

Mr. Cheatle

The Current State of Water Supply to Metro Manila from La Mesa Watershed

The Physiological, Hydrological, Ecological and Management Issues at La

Mesa Watershed Reservation

Introduction

La Mesa Dam (Figure 1.0) is located in the Novaliches Watershed. The Novaliches Watershed is a drainage basin that covers land in Quezon City, Caloocan City and the Rizal Province. The drainage basin surrounding the La Mesa reservoir covers 2700 hectares, of which 2000 hectares is forest cover. It supplies around 4 billion liters of water per day. Ninety seven percent of Metro Manila’s water supply comes from this source. Therefore, careful management is needed for this area, because of its vital importance to the health and life of the 12 million people in Metro Manila. This report will showcase the physiographic features and vegetation of La Mesa. It will also explain the hydrological system of La Mesa, the water supply, the way the water is treated and made safe for drinking. Finally, it will also include ideas as well as the pros and cons for new water sources.

Figure 1.0

The Setting: Physiographic Features, Vegetation, Soils and Rocks

Figure 1.1

The main physiographic features include: a gently undulating landscape, many small narrow streams, some streams are so small that they aren’t seen since they are passing through rock. The highest elevation is 118 meters (387 feet.) The height of the reservoir (at lake level) is 78-80 meters above sea level. The main river system in La Mesa is the Calumpit River. The land surrounding the reservoir is a plantation forest with over 12,000 species of plants. As a result it is not as dense in forest cover, and thus rain and sunlight get through more easily. The advantage of this is that there is more ground cover due to exposure to sunlight. Also in addition to La Mesa having lots of plant species, it can be said that it is a healthy environment because there is Lichen growing on the trees (Figure 1.1). This indicates that there is little pollution within the watershed, because otherwise, the lichen would not be able to grow.

The layers of forest include: Figure 1.2

The dominants (Figure 1.2):

These are the tallest trees of all the layers. These trees create most of the forest cover, as they stop the rain and sunlight from reaching the surface, and take it for themselves.

Figure 1.3

The canopy (Figure 1.3):

This layer is made up of thick woody vines which are known as lianas and they can become as thick as a person. Lianas climb trees in the canopy to reach the sunlight. The canopy also prevents rain from reaching the surface of the forest floor.

The understory (Figure 1.4): Figure 1.4

This layer is right beneath the dominants and canopy layer

and is composed of trees growing to breach the canopy layer, this is so they can absorb more light. The trees in this layer are usually small with thin trunks.

The shrubs (Figure 1.5): Figure 1.5

This layer grows between the forest floor and understory layer it is mostly composed of ferns, bushes and small trees.

The forest floor (Figure 1.6): Figure 1.6

This layer is composed of decaying vegetation and other decaying material; this is because when leaves from trees fall to the ground the microorganisms, worms and insects feast on them and produce the nutrient rich soil. However in some areas of La Mesa there is very little forest cover and this results in sunlight coming through and encouraging more growth of ground ...

La Mesa Watershed

This is a preview of the whole essay

Document Details

Related Essays

The Impact Of the Global Warming On the El Niño/La Niña.

The Impact of Global Warming on the existence of El Niño/ La Ni&ntil...

Balian River

What are the local and global consequences of deforestation?