秦岭水源涵养功能解析

Analysis of Water Conservation of Qinling Mountains

稳定且良好的水源涵养功能是区域发展的基础,生态系统的水源涵养功能是当下区域生态水文研究的关键领域。秦岭因其重要的生态功能与地理环境特征,掌握其水源涵养功能的变化、水源涵养功能空间格局、影响因素敏感性等信息具有科学和实践指导双重意义。选取陕西秦岭为研究区,基于InVEST产水模块和水源涵养模型,计算秦岭2000-2014年15年间水源涵养量的变化,从坡度、高程、坡向方面分析了水源涵养空间格局,选取降水、蒸散发、季节常数、根系深度、叶面积指数等因素敏感性。结果表明:(1)年均水源涵养量与年均降雨量基本同步波动,2000-2014年15年间秦岭水源涵养总量呈增加趋势,年均增加值为2×10^9 m^3,并且增加的趋势越来越明显。秦岭主要流域年平均水源涵养量为汉江流域>丹江流域>渭河流域>洛河流域>嘉陵江流域。(2)秦岭水源涵养功能与高程、坡度、植被覆盖度呈正相关,阴坡水源涵养量大于阳坡,子流域水源涵养功能以中等重要和重要为主,一般重要和极重要较少。(3)影响水源涵养功能关键因子参数敏感性为降雨>潜在蒸散发>叶面积指数>季节常数>植被根系深度。

Stable and good water conservation functions are the foundation of regional development.The water conservation functions of ecosystems are the key areas of current regional ecohydrological research.Because of Qinling’s important ecological function and geographical environment characteristics,it has the dual meaning of scientific and practical guidance to grasp the information as the changes of its water conservation function,the spatial pattern of water conservation function and the sensitivity of influencing factors.In this paper,Qinling in Shaanxi was selected as the research area.Based on the In VEST water production module and water conservation model,the changes of water conservation in Qinling from 2000 to 2014 were calculated.The spatial pattern of water conservation was analyzed from the aspects of slope and elevation,and the sensitivity of factors such as precipitation,evapotranspiration,seasonal constants,root depth,and leaf area index were selected.The results showed that:(1)The annual average water conservation and annual average rainfall basically fluctuated synchronously,and the total water conservation in the Qinling Mountains increased from 2000 to 2014 with the average annual increase of 2×10^9 m^3,and the increasing trend was becoming more and more obvious.The average annual water conservation in the main watersheds of Qinling Mountains was Hanjiang River Basin>Danjiang River Basin>Weihe River Basin>Luohe River Basin>Jialing River Basin.(2)The water conservation function of Qinling was positively correlated with elevation,slope,and vegetation coverage.The water conservation capacity of the shady slope was greater than that of the sunny slope.The water conservation function of the sub-basin was mainly of medium importance and importance,but general importance and extreme importance were unfrequent.(3)The sensitivity of the key factors affecting the water conservation function was rainfall>potential evapotranspiration>leaf area index>seasonal constant>vegetable root depth.