Land Degradation in the Oases on the South Side of the Taklimakan Desert

塔克拉玛干沙漠南侧绿洲土地退化

• 批准号: 10041086
• 负责人: TAKAMURA Hiroki
• 金额: $ 9.47万
• 依托单位: Rissho University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (A).
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10041086/
• 关键词: Remains; Desertification; Water quality and change of river and groundwater; Land use; Hydrological environment; change of temperature and ground soil temperature; Agriculture and stock breed; Ancient oasis communities; タクリマカン沙漠; 水文環境変化; 河川流量変動

The annual evapotranspiration varies in and around oases in the Tarim Basin. According to our calculations, the annual precipitation is about 25-100 mm, and annual evapotranspiration is about 100 mm at Khotan station. Since the potential evapotranspiration can reach above 500 mm in the oases, in some desert areas it can reach 1000 mm. The oases in the southern part of the Tarim Basin are located between 25 mm and 100 mm isohyet. Many oases in the northern part are located between 25 mm-200 mm isohyet and experienced 100 mm-200 mm isograms of annual evapotranspiration ; therefore, higher temperatures may still lead to a general increase in evapotranspiration.At present, the length of rivers in the desert changes greatly year by year due to fluctuations in the amount of discharge.For example, the annual discharge of the Keriya River (1991) is 7.0G×10^8 m^3, and 56% of that discharge (4.0×10^8 leaches m^3), is used as irrigation water for agriculture, while the remainder (3.0×10^8 m^3) in … More to the ground, recharging the groundwater annually.The Keriya River basin can be divided into the following four regions by hydrological conditions :1) In the upper part, which is located in the Kunlun Mountains, the longitudinal change in the chemical composition of river water is complicated because of the conjunctions of tributary streams.2) The middle part contains an alluvial fan, on the toe of which the Keriya Oasis is located. In this region, the downstream change in the water chemistry of the river water is very complicated.3) In the lower part, evaporation has a great in fluence on the chemical and isotopic compositions. The river water is more concentrated chemically and isotopically heavier in the lower reach.4) In the lowermost part, where the Keriya River diverges into some channels, the downstream change in the water chemistry of the river is complex and the groundwater chemistry shows a great regional variety.The irrigated agriculture practiced in the Minfeng oasis has relied on water diverted from the Niya river. Less

塔里木盆地绿洲内及绿洲周边的年蒸散量变化较大。根据我们的计算，和田站的年降水量约为25-100毫米，年蒸散量约为100毫米。由于绿洲的潜在蒸散量可以达到500毫米以上，在一些荒漠地区可以达到1000毫米。塔里木盆地南部绿洲分布在25~100 mm等水位线之间。北部许多绿洲的年蒸散量在25 mm-200 mm之间，年蒸散量在100 mm-200 mm等值线之间，因此气温升高仍可能导致蒸散量的普遍增加。目前，由于流量的波动，沙漠中的河流长度逐年变化。例如，克里亚河(1991年)的年流量为7.0g×108m^3，其中56%的流量(4.0x108m^3)用于农业灌溉，其余的(3.0x108m^3)在…根据水文条件，克里雅河流域可分为以下四个区域：1)位于昆仑山的上游，由于支流的汇合，河水化学成分的纵向变化复杂；2)中部为冲积扇，克里亚绿洲位于其脚趾上。下游河水化学变化非常复杂。3)在下部，蒸发对河水的化学组成和同位素组成有较大影响。下游河水化学成分和同位素含量较高。4)在克里雅河分流的最下游，下游河流水化学变化复杂，地下水化学具有较大的区域差异性，民丰绿洲灌溉农业主要依靠尼雅河引水。较少