| This article has been：Browse 1830Times Download 4284Times |
scan it! |
|
|
| DOI：10.13522/j.cnki.ggps.20190258 |
|
| Groundwater Dynamics in Catchment of Jiansanjiang in Sanjiang Plain |
|
LIU Weipo, SHA Na, CHENG Xuxue,LIU Weipo, SHA Na, CHENG Xuxue,LIU Weipo, SHA Na, CHENG Xuxue
|
|
Center for Hydrogeology and Environmental Geology Survey, CGS, Baoding 071051, China
|
| Abstract: |
| 【Background】Sanjiang Plain, located in northeast Heilongjiang province, refers to the flood plains of three rivers: Songhua river, Heilong river and Wusuli river. It is rich in water and land resources and is one of the main food production bases in China. Its annual grain production has reached 15 million tons, accounting for 25% of the total grain production in Heilongjiang province. Jiansanjiang is in northeast Sanjiang plain, comprising 15 state-owned farms with total cultivation area of 12400 km2. With continuous optimization and adjustment of planting structure from 1997, its rice area in 2017 was 656 600 hm2, about 3.5 times that in 1997. Jiansanjiang is rich in surface water resources with Heilongjiang and Wusulijiang rivers flowing through, but the water use efficiency still has room for improvement. Over past decades, extracting groundwater for irrigation has changed natural course of groundwater flow and the groundwater level has been in decline as a result.【Objective】The purpose of this paper is to unveil spatiotemporal groundwater dynamics in Jiansanjiang in attempts to provide baseline for improving water resources management in this region.【Method】Spatiotemporal changes in groundwater table were monitored from boreholes in the 15 farms, and we also collated data of agricultural planting structure and land usage from 1997 to 2017. The spatiotemporal changes in groundwater dynamics was analyzed using the variances of contrast coefficients, OriginPro trend and arcgis spatial interpolation.【Result】The groundwater table in the studied area had been falling at annual rates of 1.60 to 9.29 m, especially in the central-east and west region where the falling was fastest. The variance of contrast coefficient and spatial variation of the groundwater table falling were identical, with the groundwater in the central-east and west part most affected by extraction. There was a noticeably spatial variation in groundwater flow, with the gradient of groundwater table in northwest, southeast and south much steeper than in other parts. Groundwater in the proximity of the river at the confluence of the two rivers received recharge from the rivers .【Conclusion】Change in groundwater flow in the studied area was instigated by excessive groundwater extraction, which enhanced river exfiltration and accelerated groundwater flow. |
| Key words: groundwater dynamic; variance of contrast coefficients; groundwater flow; hydraulic gradient |
|
|
