东荆河水文特性变化分析研究

东荆河是汉江下游分泄汉江洪水入长江的重要分洪河道,其分流分沙的变化不仅影响东荆河流域防洪安全、水资源利用、航运等,还影响汉江、长江的防洪安全。应用大量实测水文资料,系统地分析研究了东荆河分流分沙的变化规律。研究结果表明:东荆河多年平均分泄汉江水量42.5亿m~3,占9.1%,汉江上游丹江口水库建库后,分流比变化明显;分流分沙比在丹江口建库前后变化相当,洪峰流量分流比由建库前的22.7%变化为建库后的17.9%;由于丹江口水库调蓄,东荆河断流天数有所减少,且由于受清水下泄的影响,东荆河河床冲刷作用明显,断流水位下降。研究结果对东荆河及汉江中下游河道治理、水资源利用、防洪等有一定的参考价值。

Variation analysis on hydrologic characteristics of Dongjing distributary

The Dongjing distributary is an important floodway of releasing the Hanjiang River flood in the lower Hanjiang River into the Yangtze River, its variation of flow and sediment diversion not only affects the flood control, water resource utilization and navigation of this basin, but also affects the flood control of the Hanjiang River and the Yangtze River. Based on a large quantity of measured hydrological data, the laws of runoff and sediment diverted from the Dongjing distributary were systematically analyzed. The results showed that: the average annual 4.25 billion m3 water was discharged into the Dongjing Distributary, accounting for 9.1% of the Hanjiang River, and the flow diversion ratio changed obviously since the completion of upstream Danjiangkou Reservoir; the average sediment of 5.835 million t was discharged, accounting for 13.5% of the Hanjiang River, the average sediment of 5.835 million t was discharged, accounting for 13.5% of the Hanjiang River; the flood peak flow diversion ratio was reduced from 22.7% to 17.9%. By the regulation of Danjiangkou Reservoir, the days of zero-flow were reduced. In addition, affected by clear water discharging, the river bed of the Dongjing Dstributary was obviously scoured and the dry-up water level fell. The research results have a certain reference value for the river regulation, water resource utilization and flood control of the Dongjing River and the middle and lower reaches of Hanjiang River.