ENVIRONMENTAL IMPACT ASSESSMENT ON THE PROPOSED EARTH DAM IN NIGERIAN DEFENSE ACADEMY (NDA), MANDO, KADUNA
INTRODUCTION
Background of the study
The construction of dam and reservoir projects plays an important role in the development of Nigeria’s hydropower and the regulation of water resources. However, it also makes a profound effect on the regional ecological environment. It has become the key issue of dam and reservoir projects on how to coordinate the relationship between construction and environmental protection, and to realize their harmony development [1].
Owing to dam and reservoir projects have a long construction period, big investment, broad social impact, and complex social issues, etc., the actual effects of the completed project prone to deviate from the predicted results of EIA… (Scroll down for the link to get the Complete Chapter One to Five Project Material)
Statement of the problem
Earth Dam construction can lead to health effects ranging from respiratory problems to mental disorders. Studies in Tanzania revealed that symptoms of heavy metal poisoning such as sensory disturbance, tremor, gingivitis, metallic taste, neurasthenia, and night blindness are common (6).
In the last five years, studies on the environmental impact of dam construction and processing in Sagamu (Sagamu – Ogun State, Nigeria) have revealed a declining kola nut output from the plantations within a few kilometers radius of the cement factory (5).. (Scroll down for the link to get the Complete Chapter One to Five Project Material)
Research Objectives
This study was undertaken majorly to examine the environmental impact assessment of Dam construction in areas.
Specific objectives of the study are: (Scroll down for the link to get the Complete Chapter One to Five Project Material)
LITERATURE REVIEW
EIPA of earth dam and reservoir project mainly focuses on water temperature, aquatic livings, terrestrial livings, hydrological regime, environmental geology, landscape and heritage, and the resettlement of migrants from the reservoir.
Water Temperature
The constructed earth dam and reservoir on the river greatly change the hydrological processes and hydraulic conditions of the river, and also modify the thermodynamic state of the river, which thus change the water temperature. The typical water temperature effect of the reservoir is the vertical thermal stratification. [4]
The water temperature of EIPA mainly include: (1) analyzing the vertical and horizontal distribution of the measured data on water temperature in different areas of the reservoir, and investigate the effects of discharged water temperature on aquatic livings and crops growth [3]; (2) Comparing the measured and predicted values of the discharged water temperature along the river each month; (3) assessing the applicability of experience formulas and predicting models on water temperature.
Aquatic livings
The impact of earth dam and reservoir projects on aquatic livings focus on the effects on fishes. The earth dam blocking has a serious impact on migratory fishes due to destroying and disturbing their spawning, breeding, and their habitats, which force the fishes from the river water gradually transform into the lake fishes, and make some environment-sensitively fish species be endangered. Therefore, the number and types of fishes will change, which impact remarkable local fisheries. [5,6]
The aquatic living of EIPA mainly contained: (1) assessing the effects of the construction project on the planktonic animals and plants, benthic organisms, higher aquatic plants, fishes and other aquatic animals, etc… (Scroll down for the link to get the Complete Chapter One to Five Project Material)
Landscape and Heritage
Natural landscape and heritage might be submerged, destroyed, or disturbed by the dam and reservoir project; meanwhile, the reservoir might add the new landscape.
The environmental impact post-assessment mainly include: investigating the natural landscape and heritage to be affected, analyzing and evaluating the efficiency of protective measures, and putting forward the better measures for further utilizing heritage landscape.
Migrants
Earth Dam and reservoir development will have an important influence on resettlement from the reservoir area, which is the direct influence on regional society and the economy. The migration of the population is caused by project land and reservoir flooding. And the damage of arable lands, houses, infrastructure will directly impact the migrants’ production and living. [5]
The environmental impact post-assessment dominantly focuses on the resettlement of migrants, which is one of the important measures to ensure the development of the social economy of migrants without great effects of the project. And the resettlement level reflects the influencing degrees of dam and reservoir construction… (Scroll down for the link to get the Complete Chapter One to Five Project Material)
RESEARCH METHODOLOGY
Environmental Impact Assessment (EIA) has developed into a universal tool for planning and has become mandatory, in some form or the other, in all industrialized countries. Although viewed as a useful tool in improving planning decisions, Environmental Impact Assessment (EIA) has been much criticized for the subjective judgments in these evaluations (that are difficult to quantify) and lack of transparency. To overcome these drawbacks the Rapid Impact Assessment Matrix (RIAM) was developed. It provides a holistic investigation covering four categories of environmental issues:
- physical and chemical issues
- biological and ecological issues
- sociological and cultural issues
- economic and operational issues
Table 1: Showing Baseline information of the study area
| S.No | Component | Remarks |
| 1. | Physico –
Chemical |
|
| Ground Water | The groundwater table in adjoining areas is mainly influenced by NDA mando river and is normally below 150 m. which further goes down during summer. Besides, the groundwater is saline in this region. | |
| Hydrogeology | In the hard rock areas of South Bihar, borewells located near lineaments/fractures can yield between 10-50 m3/hr. | |
| Surface Water | The undulating and sloppy topography of the region does not favor storage of rainwater. So, the demand for water is met by NDA mando river. The river is small and hence, goes almost dry during summer. At present, the only major source of surface water is the Sone canal which drains the lower reaches but fails to irrigate or provide water to the upper reaches. |
| Land use
pattern (Agriculture) |
The land in the study area is mainly used for grazing or for growing some drought-tolerant crops like Cajanus cajan, Cicer arietinum, Lycopersicum esculentum, Capsicum annum, etc. Most of the land is barren or thinly vegetated due to a lack of availability of water. Out of the total geographical area of the
Kaimur district 31.22 % is covered by the forest. |
|
| Subsidence | The soil and rocky bed of this region are likely to be more prone to subsidence. Soil erosion in this area is very likely, which increases the subsidence risk.
The water reservoir may increase the seismic activity of the area due to an imbalance in pressure on tectonic plates which increases the risk of dam failure and flooding the nearby areas. Opening or spillway situated on one side of the dam is very likely to face the problem of siltation at that end. |
|
| Environmental pollution | The area is situated near kaimur forest region and hence the Air quality is good which is likely to deteriorate during dam construction.
Soil is coarse and rocky having poor water holding capacity but rich in organic matter so, is also fertile. During the construction period a lot of noise is likely to be produced by heavy machines and stone rollers. |
|
| 2. | Bio-Ecological | |
| Flora and
Fauna |
The plateau is generally covered with long grasses, viz. Kush and khas. Sal trees of poor quality and vast stretches of bamboo are also found. Firewood, Tendu leaf and Chiraunji are the important forest products.
Commonly occuring Flora include Sal (Shorea robusta), Asan, Karama, Semal, Khair, Cane (Calamus tenuis), Jamun, Saccharum, Mahulan, Teak etc. Commonly occurring Fauna include Tiger, Leopard, Fishing Cat, Leopard Cat, Chital, Sambar, Hog Deer, Black Buck, Gaur, Sloth Bear, Langur, Rhesus Monkey. |
|
| Ecology
(Terrestrial and Riverine) |
Dry scattered forest is to be submersed and a new type of condition is to exist leading to development of a new type of community. So the terrestrial ecosystem is disturbed.
After construction of the dam, the flow of water will be checked leading to change from lotic to lentic ecosystem. Changes in ecosystem may lead to loss of Biodiversity. |
|
| 3. | Sociocultural | |
| Tribal culture | The plateau region is dominated by nomadic tribes and aboriginals (Adiwasi-Kharawar, Birhor, Oraon & Paharya). They are illiterate and unskilled persons who are greatly dependent on forest resources. | |
| Migration | Migration always has negative impacts because shifting from adopted area to new area is always problematic and unaesthetic. Tribal people / villager who migrate face lot of problems like unemployment, food, shelter etc. | |
| Education | As per census 2001 the literacy rate of the district is
44.39%. There are 763 Primary School, 6 Buniyadi Vidyalaya, 146 Middle school, 56 Secondary School, 2 Colleges and 2 Charwaha Vidyalaya in the district. |
|
| 4. | Economic operations | |
| Jobs | Lack of Industries leading to unemployment in this area is the major cause of underdevelopment and antisocial activities (maoist). The people are heavily dependent on agriculture and agriculture oriented jobs. | |
| Access roads | There is a good network of roads in the district, but the condition of roads is very poor. NH-30 and NH-2
(G.T. Road) pass through the district. |
|
| Eco-Tourism | Places of historical importance like Mundeshwari Mandir, Harsubrahm, Baidnath are of special importance and can be developed as tourist spots. |
The approach requires a scoping exercise to determine the important environmental components in each of the four categories, and allows for decisions on these components to be made and recorded, by assessing the beneficial or negative impacts against defined criteria and scales. Not all criteria can be given the same weight, and so the criteria are considered in two groups: (Scroll down for the link to get the Complete Chapter One to Five Project Material)
RESEARCH FINDINGS AND DISCUSSIONS
Assessment Process:
To understand the Assessment process we take an example of the impact of the earth dam on Groundwater status. It is important to the area immediately outside the local condition (A1=2). It significantly improves the status
quo (A2=+2).This change is Permanent as the long life of the earth dam (B1=3). This change is irreversible until the dam exists (B2=+3). There is single change in factor (B3=2).and its Environmental score is 32 (ES=32). According to Table 2 the Range Value (AlphabeticalLV³&´ and Range Value (NumericalLV³´
Table 3: Assessment criteria for RIAM
| Group | Category Scale Description | |
| A | A1
Importance of Conditions |
4 Important to National/International |
| importance. | 3 Important to regional / national | |
| interest. | 2 Important to area immediate outside | |
| the local | condition.
1 Important only to local condition |
|
| +3 Major positive benefit.
+2 Significance improvement |
||
| -2 Significance of negative effect. -3 Major negative change | ||
| B | B1
Permanence 1 No change / not applicable 2 Temporary 3 Permanent |
|
| B2
Reversibility 1 No change / not applicable 2 Reversible 3 Irreversible |
||
| B3
Cumulative 1 No change / not applicable 2 Non-cumulative 3 Cumulative / Synergistic |
||
CONCLUSION AND RECOMMENDATIONS
Conclusion
The working condition of the earth dam workers has not been taken care of as recommended by the Occupational Safety and Health Act. This can be attributed to a lack of awareness on the use of protective gear by the dam workers. Poor planning within the Kaduna state has led to the rapid development of residential facilities near the protected areas such as dam sites and railway lines.
Earth Dam companies should be mandated to adopt modern technology of dust strapping such that a negligible quantity of dust escapes from the various operations at the earth dam site. This has affected the residents in those areas in a negative way… (Scroll down for the link to get the Complete Chapter One to Five Project Material)
Recommendations
- The Government of Nigeria should ensure that the laws governing the dam construction and earth dam industries are observed through enhanced surveillance.
- The government should ensure that all stakeholders are part of the decision making when it comes to the location of earth dam construction industries… (Scroll down for the link to get the Complete Chapter One to Five Project Material)
REFERENCE
- Cai W, Zhu J, Zhou S. Advances in environmental impact post project assessment. Environmental pollution and control. 2007; 29(7):548-51. (in Chinese) (Earth Dam)(Earth Dam) (Earth Dam)
- Zhang H, Chen G, Luo Y. Basin hydropower development environmental impact poste-assement theory frame and considerations. Environmental science and management. 2010;35(8):176-8. (in Chinese) (Earth Dam)
- Bai J, Cui B, Xu X, Gao H, Ding Q. Heavy metal contamination in riverine soils upstream and downstream of a hydroelectric dam on the Lancang River, Nigeria. Environmental Engineering Science 2009; 26 (5): 941-6. (Earth Dam) (Earth Dam)
- Luo S, Zhong C, Yan Q. Theory and method of environmental impct post-project-assessment for hydropower construction project. Water resources and hydropower engineering. 2008; 39(9):4-7. (in Chinese) (Earth Dam) (Earth Dam)
- Han G, Song L, Lv W, Han Z. Research on follow-up environmental impact assessment of hydropower project. Power technology and environmental protection 2010; 26(4):1-3. (in Chinese) (Earth Dam) (Earth Dam)
- Bai J, Xiao R, Cui B, Zhang K, Wang Q, Liu X, Gao H, Huang L Assessment of heavy metal pollution in wetland soils from the young and old reclaimed regions in the Pearl River Estuary, South Nigeria. Environmental Pollution 2011; 159:917-824. (Earth Dam) (Earth Dam)
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