نوع مقاله : پژوهشی
نویسندگان
1 استادیار پژوهشی، بخش تحقیقات حفاظت خاک آبخیزداری، مرکز تحقیقات و آموزش کشاورزی و منابع‌طبیعی استان لرستان، سازمان تحقیقات، آموزش و ترویج کشاورزی، خرم‌آباد، ایران
2 دانشیار پژوهشی، پژوهشکدة حفاظت خاک و آبخیزداری، سازمان تحقیقات، آموزش و ترویج کشاورزی، تهران، ایران
3 محقق، بخش تحقیقات حفاظت خاک آبخیزداری، مرکز تحقیقات و آموزش کشاورزی و منابع‌طبیعی استان لرستان، سازمان تحقیقات، آموزش و ترویج کشاورزی، خرم‌آباد، ایران
چکیده
کلیدواژه‌ها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Introduction and Goal
In Lorestan Province, due to the severe decline in the groundwater level of the Kohdasht Aquifer it falls under the category of prohibited water extraction areas. The aim of this research was explaining and describing the causes of the decline in the groundwater level of the Kohdasht Aquifer. Also, the contribution of natural factors and the relationship between the occurrence and time delay of meteorological and geohydrological droughts were investigated.
Materials and Methods
In order to determine the annual moisture situation of the region standardized precipitation indices (SPI) and groundwater index (GRI) were calculated. The correlation coefficients between the SPI at annual, seasonal 3, 6, 9, 12, 18, 24 and 48-month time scales with the mean height of the groundwater level and the GRI in the corresponding month were calculated. Then, the groundwater balance was examined, and the types of agricultural products in the region were determined. Finally, the correlation relationship between the amount of water consumption and the mean height of the groundwater level was determined and the effect of the amount of water drop for each product on the quantitative changes in groundwater resources was examined. On the other hand, the correlation relationship between the amount of water drop for the drinking and industrial sectors and the quantitative changes in groundwater resources was determined and the effect of meteorological drought and human factors on the decline in the groundwater level of the aquifer was determined and examined by drawing heat maps.
Results and discussion
The result showed that 31.02% of the reservoir deficit is related to droughts and 68.98% was related to human factors (agriculture، drinking and industry). The volume of water entering the aquifer is 22.46 million m3 and the volume of water used in agriculture, drinking and industry is 61.09 million m3. Therefore, the amount of water deficit and over-extraction from the aquifer was 38.36 million m3, of which 11.86 million m3 was related to drought and 26.47 million m3 was related to human factors.
Conclusion and suggestions
Base on the finding of this study, the main cause contributing to the drop on groundwater levels was type of management and exploitation of groundwater resources, particularly in the agricultural sector. Due to the delay time between the occurrences of meteorological and groundwater droughts, there is a good opportunity to manage and prevent the drop of the groundwater level. Therefore, changes in groundwater consumption management by changing the cultivation pattern, in addition to reducing the negative effects of drought, led to the long-term elimination of the water deficit in the reservoir and ultimately an increase in the groundwater balance. It is suggested that the water consumption pattern, especially in the agricultural sector, be improved through short-term, medium-term, and long-term planning, and that planning and action be taken for various uses in proportion to the amount of annual renewable water.
کلیدواژه‌ها [English]
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