Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS

Response of the Changes of Shallow Groundwater Level and Quality to LUCC Driven by Artificial Factors—A Case Study in the Sangong River Watershed in Xinjiang

Expand
  • 1. Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China;
    2. Graduate School of the Chinese Academy of Sciences, Beijing 100039, China

Received date: 2004-08-08

  Revised date: 2004-11-13

  Online published: 2005-04-25

Abstract

Taking an oasis of Sangong River watershed,located on the northern slope of Tianshan Mountains of Xinjiang as a case,we studied the impacts of land use/cover change(LUCC)on shallow groundwater level and quality in the oasis of arid area,by employing the Geographical Information System (GIS),Remote Sensing (RS) and Geostatistics.Land use/cover was classified mainly into 9 types of irrigated lands,cities,towns,thorps and industrial and mining lands,shrubby lands,desert grasslands,saline or alkaline lands,swamps,reservoirs and ponds,which were extracted from aerial images in 1978,Landsat TM image in 1987 and Landsat ETM image in 1998 by visual interpretation,and groundwater data was obtained from 20 monitoring wells spreading over the entire oasis.The result of research showed that the shallow groundwater level and quality reflected remarkable spatio-temporal changes-in alluvial-diluvial fans descended at avg 45cm per annum in past twenty-five years,the whole trend of water table in phreatic overflowing zones went into a rapid descent,especially in the 1990's,the maximal degree of decent reached 10m.The water table of irrigated land in the under part of the alluvial plain ascended at avg 7cm per annum.The groundwater quality of oasis became more and more deteriorative with an increase in mineralization during 1987 to 1998.The isogram of mineralization in oasis transformed from 200~600mg/l in 1987 to 300~1 500mg/l in 1998,and the degree of increase in mineralization reached 100%~200% at the downstream of the oasis.Anion transited from HCO3- to SO42- and CI-,and cation had a transition of Na+,K+,Mg2+ to Ca2+ in groundwater quality in south-north direction.All of these had close relations with exploitation of land resources,irrigation and drainage,surface evaporation and use of chemical fertilization.In a word,the change of land use/cover by human factor played decisive role in spatio-temporal changes in groundwater table and quality of the oasis in arid area.The sustaining increase in non-agriculture lands of cities and thorps and irrigated agriculture lands caused a remarkable descent in water table at upstream of the oasis,and produced a great effect on groundwater quality at the stream down of the oasis.

Cite this article

YAN Jin-feng, CHEN Xi, LUO Ge-ping, XU Wen-qiang . Response of the Changes of Shallow Groundwater Level and Quality to LUCC Driven by Artificial Factors—A Case Study in the Sangong River Watershed in Xinjiang[J]. JOURNAL OF NATURAL RESOURCES, 2005 , 20(2) : 172 -180 . DOI: 10.11849/zrzyxb.2005.02.003

Outlines

/