Author(s): Golam Salem Ahmed Salem, So Kazama, Shamsuddin Shahid
Linked Author(s): Golam Saleh Ahmed Salem
Keywords: Irrigation demand, groundwater abstraction, climatic influence, support vector machine (SVM), Northwest Bangladesh
Abstract: Groundwater can balance large swings in climate and therefore, it is considered as a reliable source for irrigation to ensure food security in the context of climate change. The objective of the present study is to quantify the direct and indirect impacts of climate change on groundwater level in Bangladesh. A Support Vector Machine (SVM) model is developed to simulate groundwater level from rainfall, evapotranspiration, groundwater abstraction, and irrigation return flow for the period 1994-2010. The study reveals the significant correlation of groundwater level with rainfall, temperature and irrigation demand. The one-degree increase of temperature is found to cause a decrease in groundwater level during irrigation period by 0. 65%, and 1% increase of rainfall is found to cause an increase of groundwater table by 0. 05%. Similarly, 1% increase in groundwater abstraction is found to cause a decrease in groundwater table by 1. 14 %. On the other hand, one- degree increases of temperature cause an increase in irrigation demand by 2. 48%, which may cause a declination of groundwater level by 2. 93 %. On the other hand, 1% increase of rainfall causes a decrease in groundwater abstraction by 0. 59%, which increase of groundwater table by 0. 48%. The study reveals the indirect impact of climate change on groundwater level through the changes in irrigation demand will be higher than direct impact due to changes in groundwater recharge. The study also reveals that impact of temperature rise on groundwater level would be much higher compared to changes in rainfall. As groundwater is the major source of irrigation in many developing countries, it is expected that the finding of the study will help in climate change adaptation and mitigation planning
Year: 2017