Reversing wetland death from 35,000 cuts: Opportunities to restore Louisiana’s dredged canals
Reversing wetland death from 35,000 cuts: Opportunities to restore Louisiana’s dredged canals
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扭转因 35,000 次砍伐造成的湿地死亡：恢复路易斯安那州疏浚运河的机会
作者：
R. Turner;Giovanna M. McClenachan
我们确定了1900年至2017年路易斯安那州14个沿海教区的石油和天然气活动许可证数量，将其与该海岸的土地损失进行了比较，并估计了其恢复潜力。总共有76，247口油气开采威尔斯井获得许可，其中35，163口（46%）位于陆地上（截至2010年），其中27，483口正式废弃。这些许可证的数量与土地损失之间存在直接的空间和时间关系，这是由于与运河平行的疏浚材料堤坝（弃土库）造成的地上和地下水文变化。这些水文变化对植物和土壤造成各种直接和间接的危害，导致湿地崩溃。虽然路易斯安那州南部湿地下的石油和天然气开采量自20世纪60年代初达到顶峰以来急剧下降，但它留下了总长度足以从东到西穿越路易斯安那州沿海79次的弃土场。将弃土堆中的剩余材料拖回运河是一种成功的恢复技术，在路易斯安那州很少应用，但如果政治意愿占上风，可能是一种极具成本效益和行之有效的长期战略。缺乏州或联邦恢复计划是一个巨大的错失机会：1）以相对较低的成本进行具有成本效益的恢复，2）进行系统的恢复监测和假设检验，以提高知识和提高未来尝试的有效性。运河的价格约为3.35亿美元，占该州恢复总体规划的0.67%，也是过去100年来开采石油和天然气所获得的经济价值的一小部分。
We determined the number of permits for oil and gas activities in 14 coastal Louisiana parishes from 1900 to 2017, compared them to land loss on this coast, and estimated their restoration potential. A total of 76,247 oil and gas recovery wells were permitted, of which 35,163 (46%) were on land (as of 2010) and 27,483 of which are officially abandoned. There is a direct spatial and temporal relationship between the number of these permits and land loss, attributable to the above and belowground changes in hydrology resulting from the dredged material levees placed parallel to the canal (spoil banks). These hydrologic modifications cause various direct and indirect compromises to plants and soils resulting in wetland collapse. Although oil and gas recovery beneath southern Louisiana wetlands has dramatically declined since its peak in the early 1960s, it has left behind spoil banks with a total length sufficient to cross coastal Louisiana 79 times from east to west. Dragging down the remaining material in the spoil bank back into the canal is a successful restoration technique that is rarely applied in Louisiana, but could be a dramatically cost-effective and proven long-term strategy if political will prevails. The absence of a State or Federal backfilling program is a huge missed opportunity to: 1) conduct cost-effective restoration at a relatively low cost, and, 2) conduct systematic restoration monitoring and hypothesis testing that advances knowledge and improves the efficacy of future attempts. The price of backfilling all canals is about $335 million dollars, or 0.67% of the State’s Master Plan for restoration and a pittance of the economic value gained from extracting the oil and gas beneath over the last 100 years.