Impacts Of The Urbannization On Water Quality Of Cau River In Bac Ninh City

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I. INTRODUCTION

Water resource is an essential component of the living environment. It contributes to

the success of economic and social development, planning, and national security.

Nowadays, our national resource is facing the risk of pollution and depletion. The rapid

development and the high population density are causing severe pollution in many rivers.

With economic development, people often have ignored the direct or indirect adverse

impacts on the environment. The risk of lacking clean water is a major threat to the

survival of human and all living organisms. Therefore, we are in need of having

appropriate measures to protect and use water resources rationally.

Cau River (Nhu Nguyet River) is an important tributary of Thai Binh river system. The

watershed area of the Cau River is about 6,030km2

, and the river is about 290 km long. It

provides water to agricultural and industrial activities in six provinces including: Bac Kan,

Thai Nguyen, Bac Giang, Ban Ninh, Vinh Phuc, and Hai Duong.

In Bac Ninh province, Cau river is about 70 km long, flowing through Yen Phong

district, Bac Ninh city, and Que Vo district. The river through Bac Ninh city is

approximately 30 km long. The river’s water quality is affected by pollutants from Dai

Lam alcohol-making village (Tam Da- Yen Phong), Ngu Huyen Khe River – which

receives waste water from the iron and steel – producing villages in Chau Khe, Van Mon

aluminum recycled village, Phong Khe paper-making village, and many households living

on both sides of the river.

However, for a long time, the extent and level of water pollution caused by urbanization

in Bac Ninh city have been unclear. Therefore, implementing a study on the effects of

urbanization on water quanlity of Cau River in Bac Ninh city is urgent and necessary to

provide a more scientific basis for the river water protection and improvement.

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II. SCOPE, GOAL, OBJECTIVES, AND HYPOTHESIS OF THE STUDY

2.1. Scope of the study

- This study just focused on analyzing some parameters to compare water quality in

upstream and downstream of Cau River in Bac Ninh city.

- This study focused on clarifying some main sources of pollution from urban activities

for water quality of Cau River in Bac Ninh city.

2.2. Goal

This study aims to contribute to provide scientific bases for water resources protection

and improvement in order to meet the need of society in a sustainable way.

2.3. Objectives

- To assess the present water quality of Cau River in Bac Ninh city.

- To assess the impacts of the urbanization on Cau River’s water quality.

- To propose the most suitable measures to prevent impacts of the urbanization on water

resources of Cau River in Bac Ninh city.

2.4. Hypothesis

The urbanization process in Bac Ninh city has resulted in negative impacts on the water

quality of Cau river in Bac Ninh city.

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III. METHODS

3.1. Literature reviews

Urbanization is one of the most detrimental forces affecting river health and one of the

biggest challenges facing watershed managements. However, methods to determine how

large-scale changes in watersheds affect local habitats are still producing varied results

(Kearns et al. 2005). Hydrologic impacts due to urbanization are reported to cause water

quality problems such as sedimentation, habitat changes. Several of the changes wrought

by urbanization can affect the natural stream temperature regimen. The effect of reduced

shade upon maximum stream temperatures has been well documented (Brown, 1969;

Brown and Krygier, 1970; O’Dell, 1971; Ringler and Hall, 1975; and Hartley, 1975).

Urban runoff can affect water chemistry by changing levels of nutrients and heavy metals

(Porcella and Sorenson 1980, Morse et al. 2002). The impacts from urbanization can cause

changes in the biological communities of the stream ecosystems (Morse et al. 2002,

Chadwick et al 2006, Voelz et al. 2005, Walsh 2006). In addition, urban areas contain

many people in relatively small area, and the activities of these people produce pollutants

and cause pollution. Fortunately, most urban area pollutants are of a point source nature

and are controlled by discharge regulation. So urban impacts are especially concerning

because they can be seen throughout watersheds, and not just on a local level (Kearns et al.

2005). Impacts can be seen on multiple scales, and it is important to look at how watershed

impacts of increasing urban development and land use affect habitats on a local scale.

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3.2. Study area

This study will focus on the area of Bac Ninh city as shown in the following map:

3.3. Sampling

Collecting samples at 2 cross-sections in 3 times:

 Cross-section 1 of Cau river (length: 100m) where water flow enters Bac Ninh city (red

star on the left of the map).

 Cross-section 2 of Cau river (length: 150m) where water flow leaves Bac Ninh city (red

star on the right of the map).

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3.3.1. On-site

 Using a meter to measure pH and temperature at 3 points per cross-section ( points

on the surface water).

o At cross-section 1: - First time (11/07/2014): 7.45-8.00 am

- Second time (11/08/2014): 7.30-7.45 am

- Last time (20/09/2014): 7.32-7.46am

o At cross-section 2: - First time (11/07/2014): 8.55-9.10 am

- Second time (11/08/2014): 8.40-8.55 am

- Last time (20/09/2014): 8.50-9.10 am

 In each time for sampling, at each cross-section, dividing into 3 blocks crossing the

river. At each block, taking 10 grab samples (500ml/grab sample) at 10 equidistant points

(figure 3.1), then labeling and saving them in a dark cool box. Totally, we had 60 grab

samples from 2 cross-sections for a sampling time.

50cm

pH, t0

point 1

pH, t

0

point 2 pH, t

0

point 3

A grab sample

A grab sample

Surface water

Block 3

Block 1 Block 2

Figure 3.1: The way to sampling at a cross-section in Cau River

Bac Ninh city Bac Giang province