黑河中游张掖市土地利用/覆盖变化的水文水资源效应分析

Hydrology and Water Resources Response to the Land Use and Land Cover Changes in Middle Reaches of Heihe River and Zhangye City

本文通过对张掖市1981年、1990年、1996年及2003年土地利用情况的分析,发现随着张掖市土地利用/覆盖的变化,研究区产生了一系列的水文水资源效应。首先,随着农田有效灌溉面积的增大,地表年耗水量从1980年的6.78×108m3增加到1999年的9.21×108m3,导致正义峡的下泻水量逐年减少,下游生态与环境急剧退化。其次使区内的蒸发格局发生变化,土地利用/覆盖变化强度较大的甘州区、临泽县和高台县年蒸散量呈下降趋势;而土地利用/覆盖变化强度较小的山丹县、民乐县和肃南县年蒸散量变化趋势不太明显。再次,由于城镇用地及工农业用地扩展,导致大量的地表水和地下水被超量开采,结果使地下水位降低,泉水溢出量减少;与此同时,工业、农业及人民生活造成的污染物使水质急剧恶化,给绿洲生态和经济可持续发展构成了严重威胁。

This paper show a series of Hydrology water resources response have been occurred along with the change of land use and land cover change （LUCC） in 1981,1990,1996 and 2003 of Zhangye city. Firstly accompanied by the increasing of availability irrigating area of farmland, the consumption of surface water increased from 6.78 10^8m^3 in 1980 to 9. 21 10^8m^3 in 1999. As a result, the runoff decreased year by year at Zhengyi Gorge hydrometric station and the ecological environment deteriorated in the lower reaches of Heihe River. Secondly, the evaporation pattern changed in research region. The following results were obtained t the evaporations declined dramatically in Ganzhou region, Linze country and Gaotai country, where the LUCC were intense,but the changes of evaporationin Shandan country, Minle country and Sunan country were not distinct, where LUCC were not intense comparing the former. Thirdly, a great deal of surface water and groundwater were consumed because of the expand of city and town.agriculture and industry, which made the groundwater level declined and the spring water resources decreased; and the pollutions come from agriculture, industry and people living have made the quality of water resources deteriorate speedy. All of these, threaten the sustainable developing of oasis economic and ecology sustainable development.