Water-food-energy nexus with changing agricultural scenarios in India during recent decades
Water-food-energy nexus with changing agricultural scenarios in India during recent decades
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DOI：
10.5194/hess-21-3041-2017
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发表时间：
2017-06-26
影响因子：
6.3
通讯作者：
Sekhar, Muddu
中科院分区：
文献类型：
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作者：
Barik, Beas;Ghosh, Subimal;Sekhar, Muddu
在印度这样人口稠密的国家，满足日益增长的水和粮食需求是一项重大挑战。这就需要广泛调查以消耗地下水为代价维持粮食安全以及高能源消耗沿着的制衡模式的变化。在这里，我们提出了一套全面的分析，评估水-食品-能源关系在印度的现状，沿着其不断变化的模式，在过去的几十年。我们发现，随着人口的增长和随之而来的粮食需求的增加，粮食产量也增加了，这是由于灌溉的加强。然而，在最近十年中（1996年之后），粮食生产的增长不足以满足其日益增长的需求，导致人均粮食供应量下降。根据重力恢复与气候实验（GRACE）卫星数据集，我们还发现过去十年印度地下水储量呈统计学显着下降趋势。区域研究表明，印度北方和中西部的趋势截然不同。印度西北部和恒河盆地中部的地下水储量减少，而印度中西部的地下水储量增加。与井数据的比较表明，GRACE衍生的存储数据与现有的井测量的最高一致性是在恒河盆地中部。在分析了过去20年的数据后，我们进一步表明，干旱后，地下水储量下降，但即使在良好的季风年后也无法恢复到原来的状态。地下水储量与农业用电量呈极强的负相关关系，农业用电量也可被视为一个地区抽取地下水灌溉的替代指标。农业用电量有增加的趋势，有趣的是，它与季风降雨量没有任何相关性，如用原始或去趋势变量计算的。这揭示了一个重要的发现，即无论降雨量如何，灌溉都得到了加强。这也导致粮食生产与季风降雨量之间的相关性下降，表明农业活动越来越依赖灌溉。我们的结论是，灌溉现在已经成为农业，以满足粮食需求必不可少的，但是，它应该被明智地调节和控制，从季风降雨的水的可用性的基础上，特别是在干旱年后，因为它是必不可少的，从以前遭受的赤字恢复。
Meeting the growing water and food demands in a densely populated country like India is a major challenge. It requires an extensive investigation into the changing patterns of the checks and balances behind the maintenance of food security at the expense of depleting groundwater, along with high energy consumption. Here we present a comprehensive set of analyses which assess the present status of the water-food-energy nexus in India, along with its changing pattern, in the last few decades. We find that with the growth of population and consequent increase in the food demands, the food production has also increased, and this has been made possible with the intensification of irrigation. However, during the recent decade (after 1996), the increase in food production has not been sufficient to meet its growing demands, precipitating a decline in the per-capita food availability. We also find a statistically significant declining trend of groundwater storage in India during the last decade, as derived from the Gravity Recovery and Climate Experiment (GRACE) satellite datasets. Regional studies reveal contrasting trends between northern and western-central India. North-western India and the middle Ganga basin show a decrease in the groundwater storage as opposed to an increasing storage over western-central India. Comparison with well data reveals that the highest consistency of GRACE-derived storage data with available well measurements is in the middle Ganga basin. After analysing the data for the last 2 decades, we further showcase that, after a drought, the groundwater storage drops but is unable to recover to its original condition even after good monsoon years. The groundwater storage reveals a very strong negative correlation with the electricity consumption for agricultural usage, which may also be considered as a proxy for groundwater pumped for irrigation in a region. The electricity usage for agricultural purposes has an increasing trend and, interestingly, it does not have any correlation with the monsoon rainfall as computed with the original or de-trended variables. This reveals an important finding that the irrigation has been intensified irrespective of rainfall. This also resulted in a decreasing correlation between the food production and monsoon rainfall, revealing the increasing dependency of agricultural activities on irrigation. We conclude that irrigation has now become essential for agriculture to meet the food demand; however, it should be judiciously regulated and controlled, based on the water availability from monsoon rainfall, specifically after the drought years, as it is essential to recover from the deficits suffered previously.