2000-2014年江西东江源区水源涵养量时空变化

Spatio-Temporal Variation of Water Conservation in the Source Area of the Dongjiang River in Jiangxi Province of China from 2000 to 2014

探讨和分析区域水源涵养量的时空分异特征及其主导影响因素,是定量评估区域生态系统水源供给服务的重要内容,也是进行区域生态系统保育与管理的迫切需求。江西东江源区是一个以水源涵养为主的生态功能区域,但缺乏对该区域水源涵养量的时空变化及其影响因素的定量研究,不利于生态保育工程和生态环境补偿措施的实施。本研究应用InVEST模型,模拟分析了东江源区2000—2014年水源涵养量时空分布及其变化特征,并利用地理探测器定量识别影响其空间分异的主要因子。结果表明:(1)研究区年均水源涵养量为42.92~110.99 mm,平均为74.65 mm,总量约为1.47×10^(8)~3.80×10^(8)m^(3),其中森林和耕地多年平均水源涵养量分别占源区水源涵养总量的87.12%和10.12%;(2)总体上看,2000—2014年东江源区大多数区域水源涵养量呈略微下降趋势,但变化趋势不显著(p>0.1);(3)降雨量和蒸散发量是影响东江源区水源涵养量时间变化的主要因子,土地利用类型和降雨量是区域内水源涵养空间分布差异的主导因素。本研究可以为制定东江源区生态补偿标准和优化水源涵养林保育和管理提供重要依据。

To explore and analyze the spatio-temporal differentiation of regional water conservation and its leading influencing factors is an essential part of the quantitative evaluation of regional ecosystem water supply services,and an urgent need for regional ecosystem conservation and management.The source area of the Dongjiang River in Jiangxi province of China was allocated for building up an ecological functional area with water conservation as work emphasis,which matter to social and economic development of the basin.However,the lack of quantitative research on the pattern of water conservation and its influencing factors is not conducive to the implementation of ecological conservation projects and ecological environmental compensation measures campaigned by local governments.In this study,the calibrated Integrated Valuation of Ecosystem Services and Trade-offs(InVEST)model was used to simulate the spatial and temporal distributions of water conservation in different types of ecosystems in the source area of Dongjiang River from 2000 to 2014.The main factors affecting the spatial distribution differences of water conservation were identified quantitatively using the geographic detector method.Results show that:(1)The average annual water conservation in the study area was 42.92~110.99 mm(average of 74.65 mm),which was approximately 147~380 million m 3,of which forests and cultivated land accounted for 87.12%and 10.12%of the total water conservation,respectively.(2)Mann-Kendall trend test showed that water conservation in most regions of the Dongjiang River source area decreased slightly;in addition,this change trend was not significant(p>0.1).(3)The attribution analysis indicated that rainfall and evapotranspiration were the main natural factors that affected temporal variations in water conservation,while land use type and rainfall were the main factors that affected spatial variations in water conservation.These findings provide an important basis for establishing ecological compensation standards and for optimizing the conservation and management of water conservation forests in the source area of Dongjiang River.