Ana səhifə

Environmental Management Framework (emf) coastal embankment improvement project phase-i project (ceip-i) April 29, 2013 Dhaka Bangladesh Water Development Board Ministry of Water Resources Government of the People’s Republic of Bangladesh


Yüklə 7.67 Mb.
səhifə13/35
tarix25.06.2016
ölçüsü7.67 Mb.
1   ...   9   10   11   12   13   14   15   16   ...   35

6.3Environmental Impacts due to Afforestation


  1. Afforestation without appropriate planning and management techniques destroys the undergrowth grass cover and becomes ineffective for erosion protection. In such cases, afforestation results in the weakening of the embankment without any substantial contribution to its stability.




  1. To achieve and to maintain the desired biological protection, the following conditions were identified as the main prerequisites:




        • Site Specific Planting Material Selection


Impacts- Site specific Plantation selection will be an important steps for project preparation. If the site and plantation selection are wrong, project activities will trigger adverse impacts on the local environment and cultural heritage. Distribution of planting land and species is not only affects the efficiency of mixed forests but also the habitat of wildlife and the landscape of nature reserves.
Mitigation-Planting material selection needs to be raised from seeds originating locally and match well to the local site conditions. The species mixture has to respect the individual growth characteristics and to be geared to generate synergies in the vegetation cover and improvement of soil quality. Otherwise, the plantation will not bring the expected benefits. The type of planting species should be selected according to the locations. For example, the raised foreshore land of the embankment which is subject to occasional inundation by very high tide is not suitable for mangroves. But certain terrestrial species could be tested.


  • Pesticides

Impacts- During any plant disease outbreak, the borrower may need to use pesticide. The misuse of pesticide will cause adverse environmental impacts. The application of pesticides can kill the natural predator of harmful insects, and cause biodiversity decline and the unbalance of species. The pesticide can pollute water supplies and soil, and endanger the health of the residents, livestock, crops, and wild animals, directly or indirectly. And the pesticide spraying equipment will contaminate the water and soil if not cleaned correctly.
Mitigation- A Pest Management Plan should be prepared for specific areas where needed, considering the type of pest/insects and their possible impacts. Plant diseases and insect pests control should use precaution and microbiological processes. The 1st species of first and second category of pesticides are forbidden to use. The first year of the planting farmyard manure will be applied and then the organic fertilizers will be used after. These will improve the physical and chemical properties of soil, and cause slight adverse environmental impact. Besides, the packing receptacle of the pesticides and fertilizers should be collected and treated centralized, and also the vessel must be forbidden to wash in the river or lake.


Impacts- One nursery is expected to be established for every five hectares of plantation. Due to the humid weather effect of Bangladesh, Bangladesh uses cost effective plastic (poly propylene) bag instead of biodegradable bags for seed germination. Use of polythene is banned in Bangladesh. PP bags are non degradable, If PP bags are not collected properly after plantation, non degradable PP bags may create long term water logging.

Mitigation-BFD will ensure collection of the PP bags in a borrow pit at each site. The collected bags can be handed over to private sector for recycling. Although, use of polythene bag is banned in Bangladesh, BFD received permission from MOEF to use poly propylene bags of minimum 55 n thickness only for seed germination back in 2007. A copy of the exemption letter is attached in Annex H.

Responsibility

  • The community will be trained by BFD and involved in the Afforestation Program

  • BWDB will ensure and supervise implementation of the environmental management during implementation and operation

  • BWDB can seek assistance of third party environment specialist/supervision consultant input for ensuring environmental impacts have been addressed adequately during implementation and maintenance



6.4Potential cumulative impacts in the CEIP polder area


  1. Since the coastal polders will be rehabilitated and improved in phase by phase, it is a concern that the improvement of one polder might have impacts on flooding or salinity pattern outside the polder. For instance, when considered individually, the raising and strengthening of embankments in a given polder to withstand higher storm surges will benefit the people inside the polder and has very little long term impact outside the polder. The higher embankment has an impact only during the rare occurrence of a storm surge affecting that particular polder (say once in 10 years or so), and that also for a day or two. Such events do not cause long term morphological change or salinity impacts except within polders that have been flooded. However, there is a related impact on storm surge levels outside the polder. If more and more polders are protected from storm surges by higher embankments, their cumulative effect would drive the storm surge levels even higher, and possibly further upstream along the river system. Preliminary analysing of the location and proposed design specification (including CC impacts) of first phase 17 polders shows that most of the polders will not have significant impact on storm surge level and cumulative impact on other polders, as they are located either on the bank of big river and sea or far from the coast on the northern side of the Sundarbans. Only few polders (39/2C, 41/1, 43/2C, 47/2) might have slight impact on increasing storm surge level and cumulative impact on other surrounding polders.




  1. Nevertheless, as more polders will be protected in subsequent phases the design crest level would be driven higher. Thus it is important to look into the possible cumulative effect and residual impacts of rehabilitation of coastal polders.




  1. Furthermore, due to improved drainage system and flood protection, living standard of people will be high, more agriculture practices and industrialisation are expected. Therefore, water pollution by chemical fertilizer, pesticides and industrial effluents can be foreseen to increase in the coastal area.
1   ...   9   10   11   12   13   14   15   16   ...   35

Verilənlər bazası müəlliflik hüququ ilə müdafiə olunur ©atelim.com 2016
rəhbərliyinə müraciət