新疆和田地区地下水资源及其可持续开发利用

和田地区地下水具有一定的开发潜力,但地下水的可开采资源量依地表水的开发程度不同而变化。如果地表水引水率维持现状,则地下水最大可开采量为地下水天然补给量的55.8%,截取的蒸发蒸腾量为604%,同时泉水的消减率为35.56%。若地表水的引水率达80%,渠系利用系数提高到0.55时,地下水最大可采量为天然补给量的59.7%,截取的蒸发蒸腾量为70%,而泉水的消减率为49.4%。地下水的开发必须与保护并重,首先应加强昆仑山区的冰雪资源和水源涵养林的保护,合理开发平原区地下水与地表水;其次应积极预防地下水的污染及可能产生的生态环境负效应;同时必须加强基础建设和能力建设,提高全民节水意识。

Groundwater Resources and its Sustainable Development in Hotan Region, Xingjiang

The Hotan region is situated on the north piedmont of Kunlun Mountain and in the south edge of Tarim Basin, which cuts across two structural geology units-the southwest depression (Hotan depression) and the southeast depression (Yutian-Roqan depression). In the later Tertiary, with the violently fold uplift of Tianshan geosyncline and Kunlun geosyncline, Tarim basin began to subside down quickly and developed into an integrated vast inland basin. The Quaternary aquifers with the Tertiary impermeable bed, both confined and unconfined and formed by loose diluvial and alluvial cobble gravel, gravel, sand gravel, fine sand and clay, are the main aquifers in this region. The thickness of aquifers is about 200~900 m. The depth of groundwater table varies from 50~100 m in piedmont slope plain to 1~3 m in the fine soil plain, and the water salinity is 1~3 g·L^-1 in the former, and 3~5 g·L^-1 in the later. The water quality in the ancient channels is better than that in other regions. The majority of groundwater resources is seepage transformation of surface water including runoff and irrigation water, which is accounting for more than 94% of total groundwater recharge with a value of 3.67×10⁹ m³·a^-1. There is potential to a certain degree for groundwater development in the piedmont plain of Hotan region. But the safe yield is different according the surface water utilization rate. If the surface water use keep the scale as now, the maximum safe yield of groundwater is about 2.05×10⁹ m³·a^-1 that is 55.8% of the groundwater recharge. Thus the evapotranspiration discharge will reduce 60.4%, while spring water reducing 35.6%. If the surface water use rate is up to 80% and coefficient of canal water use in the future up to 0.55, the maximum safe yield of groundwater will reduce to 1.85×10⁹ m³·a^-1 with the groundwater recharge reducing to 3.1×10⁹ m³. The quantitative aspect of resources availability for sustainable development is a basic concern for the evolution of water management. However, the quality aspect is also of critical importance and is closely linked with the quantity aspect. The protection of groundwater quality must be taken seriously. Assessing and mapping of groundwater vulnerability, and setting up groundwater quality controlling program are key measurers and plans. Besides, the legislation, administrative management and the technology construction, and ability construction are also important and necessary.