WATER PROBLEM IN THE STRATEGY FOR SOCIO-ECONOMIC DEVELOPMENT OF NAM ĐỊNH PROVINCE

ĐÀO HUY QUÝ, LÊ ĐỨC NGÂN, ĐÀO MẠNH TƯỜNG

Nam Định Department of Science and Technology

Abstract: Located in the south of the Bắc Bộ Plain, the Nam Định  Province possesses an abundant water reserve, able to meet the socio-economic development requirement. However, the surface water begins to be polluted by discharge of untreated waste-water into canals and rivers, and the groundwater starts decreasing in quantity due to the uncontrolled exploitation. The paper sets forth some recomendations for a sustainable exploitation and use of the water resource in the province.

I. GENERAL VIEW

1. Location

The Nam Định Province in located in the south of the Red River delta. Its total area is 1.638.07 km², including 10 administrative divisions. The total number of communes is 226, among them there are 15 precincts and 9 townlets.

It is bordered in the east by Thái Bình province, in the west by Ninh Bình province, in the south by the Bắc Bộ gulf.

2. Socio-economic dimension

Population: 1,945,661, population growth rate: 0.96 %/year.

Economy:

- Economic growth:  period  2001 – 2003: 7.7 %/year.

- GDP in 2003: 7,481,750 million VND; among them: agriculture, forestry, aquaculture: 2,759,090 million VND; industry and construction: 1,876,645 million VND; service: 2,846,015 million VND.

- Economic structure: from  2001 to 2003, it was planned to reduce agricultural sections and to increase industrial, service sections (2003): agriculture, forestry, aquaculture: 36.88%; industry and construction: 25.08%; service: 38.04%.

Main strategies for socio-economic development till 2010:

- GDP growth rate: 8.5%;

- Agricultural, forestry, aquaculture revenue growth rate: 3.5%;

- Industrial revenue growth rate: 25%;

Service revenue growth rate: 8.2 - 8.5%.

In order to accomplish these tasks, Nam Định has carried out 6 socio-economic programs which are set forth by the Provincial Party Congress.

- Industrial and craft industrial development programs;

- Marine economy development program;

- Agricultural development and new country construction programs

- Poverty-alleviation movement

- Social evil elimination programs

- Consolidating programs for Communist Party, Provincial Fatherland Front and social organizations.

II. WATER RESOURCE IN NAM ĐỊNH PROVINCE AND SOCIO-ECONOMIC DEVELOPMENT PROGRAMS

1. Water resource for aquaculture

a. Potentiality for development

Nam Định coastal zone: Nam Định province has part of 72 km long coastline. There are 3 large estuaries (Ba Lạt estuary of the Red River, Lạch Giang estuary of the Ninh Cơ River and Đáy estuary of the Đáy River). The salt-marsh alluvial area is 22,500 ha, which is favourable for aquaculture.

Planning till 2010:

Table 1. The onshore aquaculture area (ha)

Table 2. Interior field area for aquaculture

Nam Định interior area: Nam Định Province has a dense hydrological system, including 4 large rivers: Red River, Đáy River, that are the 2 largest rivers crossing the province, as well as Đào and Ninh Cơ Rivers that are 2 tributaries of the Red River. The hydrology network occupies 3% of the total area. The river density is 1,5-2 km/km². A preliminary estimation shows that the total annual water discharge is 120 billion m³, whereas the annual water demand is about 27 billion m³. Hence this hydrological system and provincial irrigational works form good potentialities for aquaculture.

b. Disadvantage

Beside potential advantages, the province still is facing several challenges:  

- The Red and Đáy rivers receive polluted components from the upper source (Hòa Bình, Hà Nam, Hà Nội, Sơn Tây, …) before running across the province. The monitoring results from several observation stations in rainy and dry seasons have been showing that: the water quality reaches the river quality standard, because of dilution and self cleaning. However in comparing with fresh water standard (based on BOD, COD, Coliform, residues of insecticide, detergent…), the water quality fails to meet the fresh-water standard. This is the consequence of the direct discharge of untreated wastewater into the rivers.

- In the lower section of Red, Ninh, Đáy rivers the environmental indices (BOD, COD, insecticide residues...) are much higher than the permitted standard. The reason is that agricultural activities in the province utilize annually approximately 300 tons of insecticides.

2. Water resources for agricultural development

a. Agricultural development planning

According to the Nam Định land use planning till 2010, the total area for agriculture is  213,000 ha, occupying 63 - 64% of provincial natural land, among them:

- Rice field area: 155,000 ha;

- Cereal crop area: 16,000 ha;

- Vegetable cultivation area: 28,000 ha;

- Short-term industrial crop area: 14,000 ha.

b. Water resources for agricultural development

Nam Định has a dense hydrologic network, including 16 small and large rivers, occupying 3% of natural land. The river density reaches 1,5 - 2 km/km² and the area for irrigational works is 12,000 - 13,000 ha. This network is important for agricultural development as it is resource and infrastructure.

c. Challenges

At present, all untreated wastewater from industrial and living usages discharge directly into the river system. Additionally, the large Red and Đáy rivers still receive pollutants from the upper section before running across the province.

3. Water resource for industrial and craft industrial development

a. Current status and planning for industrial and craft industrial development

The main industries of the province are: garment, processing, mechanical, electric, electronic, construction material and oriented knowledge industries. The total area for industrial infrastructure is 99.4 ha (5.5 % of provincial land).

Till 2010, Nam Định plans to hasten the industrial development. In the planning side, several industrial zones will be constructed.

b. Water demand

- Industrial water demand: 45 m³/ha/day, water demand estimation: 56,500 m³/day.

- Estimated labour force for industrial zones: 150,000 people, water demand: 15,000 m³/day.

Total industrial water demand is: 56,500 + 15,000 = 71,500 m³/day.

c. Water potentiality for industry - craft industry

Nam Định has a dense hydrologic system with an annual water discharge of 120 billion m³, in addition all industrial zones are located close to traffic lines and surface water sources, and hence water for industrial/ craft industrial development is favourable.

On the other hand, groundwater (not detailed touched upon in this paper) is also abundant for exploitation. The facing problem is to build a water supply factory.

Table 3.  Land used in industrial production

d. Challenges

All provincial industrial zones still do not have any wastewater treatment station, in except of Hòa Xá (where the wastewater treatment station construction is under implementation, with a capacity of 4,500 m³/day for stage 1 and a total capacity of 9,000 m³/day). All the other industrial zones discharge directly into open channels, or let infiltrated through the ground, that causes the water pollution.

Untreated living usage wastewater of Nam Định City is directly discharged into lakes and Đào River, causing water source pollution.

4. Water demand for living usage

a. Population and orientation of urban development

Population: 1,945,661 with following distribution:

- Rural area: 1,654,312 persons

- Urban area: 291,349 persons

- Annual population growth rate is 9.62% (data in 2003). The estimated population till 2010 will be about 2,039,247 with following distribution:

- Rural area: 1,733,719 persons

- Urban area: 305,333 persons.

b. Water demand

Table 4. Estimated water demand till 2010

Table 5. Average rainfall during several years

Table 6. Maximum and minimum mean water discharge in a month

Source: Hydrometeorology Station in 1998

c. Water potentiality for residential usage

Water sources for living usage include rain water, surface water and groundwater.

- Rainfall (Table 5)

-Surface water (Table 6 shows the average water quantity in several months)

- Groundwater

According to several groundwater investigations in Nam Định province, from preliminary (1995) to detailed study (2004), there are six aquifers differing from one another in water quantity and quality, two of them are exploitable, these are:

+ The Holocene interstitial aquifer (Thái Bình Formation). This aquifer is distributed extensively in all districts of the province. Groundwater can be found in sand lenses of 2-3 m in thickness. These lenses lie mainly in the depth of 8-10 m and 12-15 m. 

Cl content in this aquifer ranges from 30-40 mg/l to 2000 mg/l (the study work divides it into several levels: less than 200 mg/l occupying 25%, 200-400 mg/l occupying 40% of total area. Local inhabitants usually exploit water in this aquifer for daily usage.

+ Middle-Upper Pleistocene interstitial aquifer (Hà Nội Formation). This aquifer is largely distributed in the province; it is the extension of the widely distributed aquifer in the Bắc Bộ Plain. Main sedimentary composition consists of quartz, gravel, sand. The distributive depth of this aquifer is relatively stable. In the Vụ Bản district it is about 3-35 m from the surface. In the center of Hải Hậu District, it is nearly 80-90 m or 100 m. The depth gets 60-70 m in the coastal zone. The aquifer average thickness is 28,4 m, its quality ranges from fresh to salt-water. Geologists have defined several fresh-water lenses distributed in Nghĩa Hưng, Hải Hậu, part of Giao Thủy, Xuân Trường, southern part of Nam Trực, Trực Ninh districts. The total area of fresh-water lenses is 975 km². Iron content in this aquifer is distributed in accordance to the rule: the fresher water contents less iron. The water with an iron content of less than 1 mg/l has been found in Hải Hậu and a part of Nghĩa Hưng with the total area of 105-110 km². It is estimated that potential exploitable reserves of fresh water in the Pleistocene aquifer are 203,445m³ per day. These reserves comprise of static elastic reserves (177,770 m³ per day, occupying 87.37%) and penetrating reserves (25,683 m³ per day, occupying 12.63%).

Table 7. Current status of exploitation and use of water supply works (data of 1998)

d. Challenges

- Surface water: Wastewater from agricultural, industrial and living activities directly discharges into rivers, but in comparing to the standard of river water quality the pollution is under the permitted limit, however in comparing to standard of living usage water it is several times higher.

- Ground water: There are some signs of water table lowering and pollution (especially with organic compounds and ammonia) in fresh-water lenses in Nam Định Province. The reasons simply are uncontrolled management of fresh-water exploitation and shortcomings in technical application. At present, the investigation has been showing that zinc content is 1-5 times higher than standard value as iron content is 2-10 times higher. Another groundwater investigation realized by the Institute of Geological Sciences and University of Mining and Geology also shows that from 1996 to present, the water level in water lens center decreased by 3,5 m.

III. CONCLUSIONS AND RECOMMENDATIONS

1. The Nam Định Province is known as a potential land for economic development (marine economy, wet rice cultivation, industry and service) in the Red River delta. Its water resource, including abundant surface water and groundwater, able to meet the socio-economic development demand. 

2. In order to sustainably exploit the water

resource of the province, in the managerial and technical point of views, following proposals can be set forth:  

a) On management side:

Urgent requirement of cooperation between the provinces located in the Red and Đáy river basin in order to minimize the pollution from waste sources, especially wastewater discharge.

Establishing an environmental monitoring system in the province, especially for fresh- water lenses in coastal districts. 

Closely controlling groundwater drilling enterprises, conforming to provincial planning and technical requirement. At present this task is out of control.

b) On the technical side:

All water exploiting wells need to be strengthened to prevent salt-water penetration and pollutant infiltration from surface. The well reinforcement and isolation can be done as follows: the space between drill wall and casing should be filled with clay. The zone of 3-5 m in depth from the surface water should be concreted by fast hardening cement. The base should be concreted.

Exploring and unusable wells must be filled with clay and covered by concrete.

Drilled and digged wells should be at least 3 m far from cattle sheds and toilets.