页岩气开发区井场开发对土地利用和生物量的影响

在我国四川页岩气开发区井场周围受人类活动影响较大的村镇、农田,页岩气开发对土地利用变化、植被生物量影响还不清楚.本研究利用2012、2017年遥感影像解译及2017年地面样方调查数据,分析页岩气开发区的井场、缓冲区土地利用和生物量变化,分析页岩气井区的影响范围及其造成的植被生物量损失.结果表明: 2012—2017年间,页岩气开发使93.81 hm²土地转化为工矿用地,其中,近一半(48.6%)为旱地(45.61 hm²),17.2%为有林地(16.13 hm²)、11.0%为居民点(10.28 hm²)、11.1%为灌木林地(10.39 hm²);页岩气井区开发阶段影响范围在0~50 m,在进入稳产阶段后影响范围减少;页岩气开发造成研究区植被生物量损失2477.53 t,其中,71.6%由井场直接压占造成,其余(28.4%)由井场附属道路及临时占地引起.页岩气井场直接压占旱地和有林地是页岩气开发区土地利用变化和生物量损失的重要原因.本研究可为该区域的生态环境管理、页岩气开发的可持续发展提供科学依据.

Influences of shale gas well-pad development on land use and vegetation biomass in a shale gas mining area

It is not clear how shale gas mining would affect land use change and vegetation biomass in the villages and farmlands where was substantially influenced by human activities around the well-pads of the shale gas mining areas in Sichuan Province. Using remote sensing and image interpretation in 2012 and 2017 and in situ vegetation investigation data in 2017, we analyzed the changes of land use and biomass in well-drilling fields and buffer zones and further examined the extent affected by well-drilling and subsequently vegetation biomass loss. The results showed that shale gas mining had converted 93.81 hm² of land to mining land from 2012 to 2017, among which almost half (48.6%) was dry land (about 45.61 hm²), 17.2% forest land (16.13 hm²), 11.0% residential land (10.28 hm²), and 11.1% shrubland (10.39 hm²). The extent affected by well-drilling ranged from 0 to 50 m at the early stage, which decreased at the stage of stable gas production. As a result of well-drilling, over 2477.53 t of vegetation biomass was lost, of which 71.6% being accounted for by the well-drilling fields and the remaining (28.4%) being caused by road construction and temporary land use. Direct occupation of dry land and forested land by shale gas well-pads mainly caused land use changes and biomass losses in this shale gas mining area. Our results have implications for ecological environment management and shale gas sustainable mining in this area.