Monirul Islam Md, Kanungoe P
Coast, Port and Estuary Management Division, Institute of Water Modelling, Dhaka, Bangladesh.
Water Sci Technol. 2005;52(12):251-8.
This paper presents the results of water balance study and aquifer simulation modeling for preliminary estimation of the recharge rate and sustainable yield for the semi arid Barind Tract region of Bangladesh. The outcomes of the study are likely to be useful for planning purposes. It is found from detailed water balance study for the area that natural recharge rates in the Barind Tract vary widely year to year. It may have resulted from the method used for the calculation. If the considered time interval had been smaller than the monthly rainfall, the results could have been different. Aquifer Simulation Modeling (ASM) for the Barind aquifer is used to estimate long-term sustainable yield of the groundwater considering limiting drawdown from the standpoint of economic pumping cost. In managing a groundwater basin efficiently and effectively, evaluation of the maximum annual groundwater yield of the basin that can be withdrawn and used without producing any undesirable effect is one of the most important issues. In investigating such recharge rate, introduction of certain terms such as sustainable yield and safe yield has been accompanied. Development of this area involves proper utilization of this vast land, which is possible only through ensured irrigation for agriculture. The Government of Bangladesh has a plan to develop irrigation facilities by optimum utilization of available ground and surface water. It is believed that the groundwater table is lowering rapidly and the whole region is in an acute state of deforestation. Indiscriminate groundwater development may accelerate deforestation trend. In this context estimation of actual natural recharge rate to the aquifer and determination of sustainable yield will assist in proper management and planning of environmentally viable abstraction schemes. It is revealed from the study that the sustainable yield of ground water (204 mm/y) is somewhat higher than the long-term annual average recharge (152.7 mm) to the groundwater reservoir. The reason behind this is that the rivers within and around the Barind Tract might have played the role of influent rivers.
本文介绍了水平衡研究和含水层模拟建模的结果，用于初步估算孟加拉国半干旱巴林德地区的补给率和可持续产量。该研究结果可能对规划目的有用。通过对该地区的详细水平衡研究发现，巴林德地区的自然补给率逐年变化很大。这可能是由于所使用的计算方法导致的。如果所考虑的时间间隔小于月降雨量，结果可能会有所不同。巴林德含水层的含水层模拟建模（ASM）用于从经济抽水成本的角度考虑限制水位下降来估算地下水的长期可持续产量。在有效管理地下水盆地时，评估盆地可抽取和使用而不产生任何不良影响的最大年地下水产量是最重要的问题之一。在研究这种补给率时，引入了诸如可持续产量和安全产量等特定术语。该地区的发展涉及对这片广阔土地的合理利用，而这只有通过确保农业灌溉才能实现。孟加拉国政府计划通过优化利用可用的地表水和地下水来发展灌溉设施。人们认为地下水位正在迅速下降，整个地区处于严重的森林砍伐状态。无节制的地下水开发可能会加速森林砍伐趋势。在这种背景下，估算含水层的实际自然补给率并确定可持续产量将有助于对环境可行的取水方案进行适当的管理和规划。研究表明，地下水的可持续产量（204毫米/年）略高于地下水库的长期年平均补给量（152.7毫米）。其背后的原因是巴林德地区及其周边的河流可能起到了补给河流的作用。
