半干旱区降水-土地利用变化与水沙响应关系
靳 峰1,2, 张 富1, 胡彦婷1, 周 蕊1, 王玲莉1, 唐 磊1

(1.甘肃农业大学 林学院, 兰州 730070; 2.甘肃省水利厅, 兰州 730000)

降水量; 土地利用; 水沙变化; 拟合关系

Effect of Change in Precipitation-Land Use on Runoff and Sediment Transport in Semi-Arid Areas
JIN Feng1,2, ZHANG Fu1, HU Yanting1, ZHOU Rui1, WANG Lingli1, TANG Lei1

(1.College of Forestry, Gansu Agricultural University, Lanzhou 730070, China; 2.Department of Water Conservancy of Gansu, Lanzhou 730000, China)

precipitation; land use; runoff and sediment change; fitting relationship

备注

为进一步研究年降水量、土地利用方式影响年径流量、输沙量的内在机制和关系,以定西市安定区为研究区,运用Mann-Kendall趋势检验与突变检测法研究区域年降水量、年径流量与年输沙量的变化趋势,检测突变发生的时间; 对年降水量、土地利用与年径流量、输沙量之间进行拟合和回归分析。结果 表明:(1)1957—2016年内年降水量稍有下降且不显著(p>0.05),年径流量、输沙量总体呈波动下降趋势且达极显著水平(p<0.01)。年降水量、径流量和输沙量之间的关联性,1957—1985年水沙对年降水量变化响应强烈,趋势协同性强; 1986—2016年水沙对年降水量变化响应减小,趋势协同异化,说明研究区水沙变化受其他因素(水土保持措施)影响越来越大。(2)未治理地中坡耕地、未利用地及其他用地逐年递减,与年径流输沙呈正相关且具有较好的指数、幂函数关系(p<0.01); 而治理地中梯田、人工造林、人工种草、封育及建设用地逐年递增,与年径流输沙呈负相关; 淤地坝呈先增后维持不变,与年径流输沙呈负相关。治理地及淤地坝与年径流量、输沙量均具有较好的指数关系(p<0.01)。该研究可为降水量、土地利用与水沙变化的内在机制研究提供一定依据。

In order to further study the internal mechanism and relationship of effects of annual precipitation and land use patterns on annual runoff and sediment transport, Anding District, Dingxi City, Gansu Province was selected as the research area, and Mann-Kendall trend test and mutation detection method were used to study the trend of regional annual precipitation, runoff and sediment transport, and to detect the time of mutation. Fitting and regression analysis on the relationship between annual precipitation, land use and annual runoff, and sediment transport were carried out. The results show that:(1)during the period from 1957 to 2016, the annual precipitation decreased slightly and was not significant (p>0.05), the annual runoff and sediment transport presented the fluctuating downward trend and reached the significant level (p<0.01); with respect to the correlation between annual precipitation, runoff and sediment transport, from 1957 to 1985, annual runoff and sediment transport had strongly responded to precipitation changes, and the trend was highly synergistic, from 1986 to 2016, annual runoff and sediment transport had less responded to precipitation changes, and the trend was synergistically divergent, indicating that the annual runoff and sediment change in the study area was increasingly affected by other factors such as soil and water conservation measures, especially after 2001, the impact of annual precipitation was smaller;(2)the sloping farmland, unused land and other land uses in non-controlled area were decreasing year by year, which was positively correlated with annual runoff and sediment transport, the non-controlled area had the good exponential and power function relationships with annual runoff and sediment transport, respectively (p<0.01); the terrace, artificial afforestation, artificial grass planting, enclosure and construction land in the controlled area were increasing year by year, and were negatively correlated with annual runoff and sediment transport; check dams increased at first and then remained unchanged in the channel engineering, and were negatively correlated with runoff and sediment transport, the controlled area and check dams had a good exponential relationship with annual runoff and sediment transport (p<0.01). This study can provide the basis for the understanding of the internal mechanism of precipitation, land use and annual runoff and sediment transport.