Groundwater Use for Irrigation and its Productivity: Status and Opportunities for Crop Intensification for Food Security in Bangladesh
Groundwater Use for Irrigation and its Productivity: Status and Opportunities for Crop Intensification for Food Security in Bangladesh
复制标题
DOI：
10.1007/s11269-014-0560-z
复制
发表时间：
2014-03-01
影响因子：
4.3
通讯作者：
Islam, Md Masbahul
中科院分区：
文献类型：
--
作者：
Ahmad, Mobin-ud Din;Kirby, Mac;Islam, Md Masbahul
孟加拉国人口众多，而且还在不断增长，这将需要更多的食物，并给资源带来更大的压力。旱季灌溉婆罗稻生产对国家粮食安全具有重要意义。旱季灌溉主要使用地下水，但其使用程度尚不为人所知。我们利用基于遥感的能量平衡模型、作物分类和次级统计，评估了孟加拉国西北部地区的地下水利用和水生产力。能量平衡模拟表明，实际蒸散量在325~470 mm之间有较大的空间变化，旱季总的空间平均值为365 mm。ETA的估计值与野外和区域尺度水土平衡模拟结果的独立值吻合较好。根据ETA和有效降雨量的空间估计，我们计算出2009年区域地下水净使用量为2.4千米(3)。在一些地区，地下水的使用是不可持续的，孟加拉国西北部地区季风前后地下水深度变化的空间时间序列(1990年至2010年)表明，按照目前的地下水使用水平，地下水位下降可能对该区域大部分地区灌溉农业的可持续性构成长期威胁。波罗河流域的水分生产率从0.95公斤/立方米到1.35公斤/立方米不等(3)，这使得能够确定高表现的“亮点”和低表现的“热点”，并制定缩小作物产量/生产力差距和确保未来粮食安全的战略。
Bangladesh has a large and growing population that will demand more food and place greater pressure on resources. Dry season irrigated Boro rice production is important for national food security. Dry season irrigation mainly uses groundwater, but the extent of its use is not well known. We assessed groundwater use and water productivity of Boro in the northwest region of Bangladesh using remote sensing based energy balance modelling, crop classification and secondary statistics. The energy balance modelling shows a large spatial variation in the actual evapotranspiration (ETa) from about 325 to 470 mm, with an overall spatial average of 365 mm during dry season. The estimated values of ETa correspond well with independent values from field and regional scale soil and water balance modelling results. From spatial estimates of ETa and effective rainfall, we computed regional net groundwater use for Boro production in 2009 as 2.4 km(3). Groundwater is being used unsustainably in some areas, and a spatial time series (1990 to 2010) of pre- and post-monsoon groundwater depth changes in the northwest region of Bangladesh suggests that, with the current level of groundwater use, falling groundwater levels may pose a long term threat to the sustainability of irrigated agriculture in much of the region. Boro water productivity varies from 0.95 to 1.35 kg/m(3), allowing the identification of high performing "bright" and low performing "hot" spots and the development of strategies to reduce crop yield/productivity gaps and ensure future food security.