新疆和田河流域河川径流混沌特性分析

Chaotic characteristics of annual runoff in Hotan Catchment

新疆和田河属冰川融雪及高山降水混合补给型河流,平原绿洲区降水基本不产流,其年径流主要受气温和山区降水影响,是塔里木河现今的四大源流之一。针对和田河流域和田河支流玉龙喀什河和喀拉喀什河,充分利用同古孜洛克水文站和乌鲁瓦提水文站1957-2002年共46年实测月径流时间序列所包含的丰富信息,采用自相关函数法选取延滞时间τ,重构了2条河流月径流序列的12维相空间,基于相空间重构,估算了能够表征水文系统混沌特性的定量指标即月径流序列的饱和关联维数D2和最大Lyapunov指数λ1,结果表明上述2条河流月径流序列存在相同的饱和关联维数且相关维数非整数,同时由资料所得的最大Lyapunov指数λ1也全部为正数,充分说明两条河流径流系统均存在混沌特性。

Water of the Hotan River is originated from the snow-ice thaw and precipitation in the high mountains and few runoff derives from precipitation in plain oasis, its annual runoff volume is mainly affected by the air temperature and precipitation in the mountainous area. It is one of the four headstreams of the Tarim River and the only river through the world famous Taklimakan Desert. In the paper, the chaotic characteristics of the Yulongkashen and Kalakashen River, tributaries of the Hotan River, were analyzed. In order to make full use of the abundant evolvement information contained in the monthly runoff series from wati gauge stations, the method of self-correlation function is used the phase space of 12 dimensions of the monthly runoff series of the 1957 to 2002 on both Tongguziluoke and Wuluto select the lag time τ , and by reconstructing Yulongkashen and Kalakashen River, the main quantitative indexes such as saturated correlation dimension D2 and the maximum Lyapunov exponent λ1 of the two monthly runoff series, which could be taken as the chaos features of the hydrology system, were calculated. The calculated results indicate that the monthly runoff time series of the two Rivers have same saturated correlation dimensions, which are all nonintegers. At the same time, the maximum Lyapunov exponents λ1 gained from the daturn are all positive numbers, which su^ciently shows that the runoff system Hotan River has fractal characteristics and chaotic characteristics. Identifying of east and west distributaries of the the chaotic characteristics of runoff of the Hotan catchment is helpful for understanding its evolvement laws, finding out changing characteristics of local water resources, and has reference significance for promoting economy development of Hotan Oasis, maintaining and improving the environment of the oasis, the Tarim River and Tarim basin. Here, two methods were used to i- dentify the chaotic characteristics of runoff series of river gaining water from the snow-ice thaw; and the conclusion shows that the runoff system of river gaining water from the snow-ice thaw and the system of river gaining water from precipitation are same; all of them have chaotic characteristics. At the same time, the identification of the chaotic characteristics also makes a base for non-linear forecast of river water gaining from the snow-ice thaw.