基于多源数据的黄土高原陆地水循环结构变化分析

近几十年间，黄土高原的水循环进程在人类活动与气候变化的影响下已产生了剧烈的变化。为加深对水循环结构变化的了解与认识，利用1982-2010年的降水、蒸散发、径流、土壤储水量和社会经济用水等数据，运用Mann-Kendall趋势检验和线性回归分析方法，对黄土高原的水量平衡进行评估，且细化了组成水循环的12种水文变量，并分析了水循环各分量的变化趋势及其结构的演化规律。由于网格化的社会经济用水数据（1982-2010年）对本研究产生了较大的时间限制，因此本文注重于探究这29年间黄土高原各水文变量的变化趋势及水循环结构的演化规律。结果表明：在自然系统中，蒸散发以1.97 mm/a的速率上升（P<0.01），径流、降水和土壤储水量分别以1.01 mm/a（P<0.01）、0.77 mm/a和0.46 mm/a的速率下降。在社会系统中，社会经济用水以0.50 mm/a的速率上升，其中主要由于生活、制造业、发电和采矿用水分别以0.22、0.23、0.30 mm/a和0.01 mm/a的速率增加所导致。此外，灌溉和牲畜用水分别以0.25 mm/a（P<0.05）、0.01 mm/a（P<0.01）的速率减少。就水循环结构而言，多年平均蒸散发和社会经济用水占水循环的平均比例分别为80.95%、15.27%，并以每年0.16%、0.06%的速率逐渐升高。径流、土壤储水量的变化占水循环的平均比例分别为4.00%、-0.24%，并以每年0.24%（P<0.01）、0.02%的速率逐渐下降。随着社会经济的发展和人口的增加，区域水资源供需矛盾将进一步加剧，本研究对黄土高原水资源的科学调控与可持续利用有重要参考意义。

Analysis of changes in land water cycle structure in the Loess Plateau based on multi-source data

In recent decades, the water cycle process in the Loess Plateau has changed dramatically under the influence of human activities and climate change. To better understand the changes in the water cycle structure, based on precipitation, evapotranspiration, runoff, soil water storage, and social and economic water use from 1982 to 2010, this study explored the water balance of the Loess Plateau by using the Mann-Kendall trend test and linear regression analysis method. More importantly, we detailed the composition of the water cycle 12 kinds of hydrological variables (respectively precipitation, changes in soil water storage, runoff, canopy interception, soil evaporation, transpiration, irrigation, mining, manufacturing, livestock, power generation, and domestic water use) and analyzed the changing trend of each component of the water cycle and the evolution of its structure. Unfortunately, because the gridded social and economic water use data (1982-2010) had imposed a relatively large time limit on the research, this study paid more attention to explore the changes in hydrological variables and the evolution of the water cycle structure in the Loess Plateau during the last 29 years (1982-2010). The results showed that in the natural system, evapotranspiration significantly increased at a rate of 1.97 mm/a(P<0.01). By contrast, runoff, precipitation, and soil water storage significantly decreased at a rate of 1.01 mm/a(P<0.01), 0.77 mm/a, and 0.46 mm/a, respectively. In the social system, the social and economic water use increased at a rate of 0.50 mm/a, which was mainly due to the increase of domestic (0.22 mm/a), manufacturing (0.23 mm/a), power generation (0.30 mm/a), and mining (0.01 mm/a). Moreover, irrigation and livestock water use significantly decreased at a rate of 0.25 mm/a(P<0.05) and 0.01 mm/a(P<0.01), respectively. For the water cycle structure, the multi-year average evapotranspiration and the average social and economic water use accounted for 80.95% and 15.27% of the water cycle, respectively, and gradually increased at a rate of 0.16% and 0.06% per year. The annual average runoff and soil water storage changes accounted for the average ratio of 4.00% and -0.24% in the water cycle, and gradually decreased at a rate of 0.24% (P<0.01) and 0.02% per year. With the rapid development of the social economy and the growth of the population, the competition between the supply and demand of regional water resources would be further intensified more severely. Our study has obviously important reference significance for the scientific regulation and sustainable use of water resources in the Loess Plateau.