摘要
为揭示干旱区地下水补排量演变规律及其与坎儿井流量衰减的关系,通过梳理1949年以来鄯善县水资源开发利用、地下水资源调查评价资料,分析了地下水补排量的变化,划分地下水补排量演化的阶段。利用双变量相关分析法,分析了地下水主要补排量演化与坎儿井流量衰减之间的关系,并分析了其原因。结果表明:1)鄯善县地下水补排量的变化主要受人类活动影响,气候变化的影响微弱,且主要补排量变化的突变点与国家实施改革开放、西部大开发等政策的起始点相一致,政策是人为因素中的关键因素;2)坎儿井出流量与河道渗漏补给量、渠道渗漏补给量、田间入渗补给量、机井地下水开采量之间的相关系数依次为0.312、-0.327、-0.574、-0.959,说明坎儿井流量的衰减主要受机井开采地下水影响,其次为田间入渗补给量,河道和渠道(干支渠)渗漏补给影响较小;3)坎儿井出流量与地下水补排量的响应关系主要由其空间分布位置决定。该研究对坎儿井保护和超采区治理提供参考。
In Turpan Basin, groundwater recharge and discharge system have been sharply changed due to excessive diversion of surface water and overexploitation of groundwater, so a series of ecological environment problems have been caused, such as Aydingkol Lake ecosystem deterioration, Karez flow attenuation and even drying up, land desertification, frequent sandstorm. Karez is an impressive hydraulic engineering project as well as a cultural achievement for over 2000 years. In order to preserve and revitalize some Karezes, multiple measures have been implemented. Based on the data of water use and groundwater evaluation in different period, groundwater budget was calculated, the evolution of groundwater recharge and discharge was analyzed, and the evolution stage was divided according to the variation curve over time. The relationship between groundwater system evolution and Karez flow attenuation was also analyzed using correlation analysis method. The results showed that： 1） Groundwater recharge and discharge were mainly affected by human activities. Annual rainfall was small and slightly showed a trend of decrease, and rainfall infiltration was negligible. The impact of climate change on groundwater system was negligible. River runoff increased slightly. But the river leakage decreased by around 1.0×108 m3 from 1956 to 2014. Channel leakage and field infiltration showed a trend of increase before 1990, reached the peak value of 0.359×108 and 0.168×108 m3 respectively, and then declined. Groundwater exploitation by well has experienced sustained increasing, reached the maximum of 3.536×108 m3 in 2010, and declined since 2011, and well production was 2.570×108 m3 in 2014. Karez flow increased in 1960 s to the maximum value of 2.173×108 m3, and after that decreased and drying up; only a flow yield of 0.5944×108 m3 was still provided to irrigation in 2014. Spring water, as well as Karez flow, reduced from 1.063×108 m^3 in 1958 to 0.0686×108 m^3 in 2010. The evaporation discharge of phreatic water decreased from 0.938×108 m3 in 1958 to 0.056×108 m3 in 2011. 2） The correlation coefficients between Karez flow and river leakage, channel seepage, field infiltration, and well water production were 0.373,-0.327,-0.574 and-0.959 respectively. That was to say, Karez flow attenuation was mainly affected by pumping wells, followed by field infiltration, and lastly affected by river leakage and canal seepage. The response relationship between groundwater recharge and discharge system evolution and Karez flow attenuation was decided by their spatial distribution location. In north basin, Karez system was mainly located within the areas with a width of 5.0 km north of the ground water exposure belt, at a distance of 20.0-30.0 km from the river outlet. River leakage and channel seepage were distributed into vast aquifer with an area of 2 000 km^2 in the piedmont Gobi gravel, which caused a small variation of groundwater level. Its influence is limited for most of Karez flow. Although pumping wells were located in the downstream of Karez canal, exploitation made groundwater level sharply decline and had a great influence on Karez flow. In south basin, Karez system was distributed throughout irrigation area, as well as pumping wells, exploiting groundwater caused most Karezes to be dried up and abandoned; only several Karezes located in the edge of irrigation area were still flowing. Field infiltration affected Karez flow significantly due to recharge directly. 3） The abrupt change point of groundwater recharge and discharge was consistent with the implementation stage of national major policy. Policy was a key factor in human factors. Before 1949, only Karez flow and spring water were diverted for irrigation and domestic purposes. The groundwater system was basically in a natural equilibrium. In the early days after liberation, along with the construction of diversion sluice and canal, the surface water diversion began to increase. The balance of groundwater recharge and discharge was broken. After China＇s economic reform, with the social and economic rapid development, water demand increased, the diversion of surface water and exploitation of groundwater were in sustained growth. Groundwater recharge volume and process were changed obviously. With the implementation of western develop policy, the general exploitation of oasis agriculture was getting hotter than ever. Water demand had rapid growth, while surface water supply basically reached the maximum, therefore, it was an inevitable choice to exploit groundwater, resulting in groundwater discharge volume and discharge approach to change radically.
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2016年第16期102-108,共7页
Transactions of the Chinese Society of Agricultural Engineering
基金
国家自然基金项目(41272277)
关键词
干旱
水
渠道
鄯善县
地下水系统演化
坎儿井流量衰减
drought
water
canal
Shanshan county
evolution of groundwater system
Karez flow attenuation
作者简介
吴彬，男（汉族），甘肃陇西人，副教授，主要从事内陆干旱区水资源利用与环境保护教学科研工作。乌鲁木齐新疆农业大学水利与土木工程学院，830052。Email：wubinxj@163．com
