基于长时序遥感监测的阿克苏河流域平原水库变化研究

通过水库调配、统筹兼顾生产用水和生态用水，对干旱区社会经济发展、区域环境改善及生态系统稳定意义重大。阿克苏河作为塔里木河中下游生态输水的最大补给源，其流域内的水库在维护塔里木河下游农业和生态安全稳定方面发挥着重要作用。基于EOS/MODIS卫星遥感数据，建立了长时序的水库面积遥感监测数据库，分析了2009—2020 年阿克苏河流域内的三个主要大型平原水库水域面积的动态变化，探究水库面积的年内和年际变化规律，结合人类活动和气象数据进行分析，结果表明:阿克苏河流域3 座平原水库年内面积总体呈现“前高-中低-后高”的走势，由减少趋势向增多趋势转变的时间“拐点”出现在8 月，主要与当地农业灌溉用水密切相关；同一水库月内面积变化较大，因用水需求较大，月最小面积在3—7 月变化剧烈；上游水库面积年际间逐年减少，胜利水库面积总体逐年增加；耕地面积的扩充尤其是水浇地的增加，增大了用水需求，生产用水与生态用水的竞争性用水需求加大；蒸发对平原水库有影响作用，使得水库周边局地湿度增加，局地生态改善。     

Lower delta plain interdistributary deposits — An example from the Westphalian of the Lancashire Coalfield,northwest England

A large quarry at Billinge Beacon in Lancashire, northwest England, has provided an excellent exposure of part of the Lower Westphalian A (Upper Carboniferous) Coal Measures sequence which was deposited in a lower delta plain setting. The main horizon exposed, known as the Dyneley Knoll Flags, is interpreted as the proximal reaches of two crevasse-initiated minor delta complexes, into the lower of which has been incised a sinuous minor distributary channel. The channel, which was approximately 120 m wide, built a 160 m wide channel belt by limited lateral accretion with time; vertical accretion appears to have been the dominant infilling mechanism. This produced a stacked series of epsilon cross-strata, made up of rhythmically interbedded sandstone and silty claystone. The peculiar style of infilling of the channel is ascribed to deep incision of the channel into minor delta deposits, and possibly the influence of a seasonal climate.