中亚热带红壤丘陵区农业流域景观格局对水文过程的影响

Effects of Landscape Pattern on Hydrological Processes in the Central Subtropical Hilly Agricultural Catchments

景观格局是影响流域水文过程和水分循环要素分配的重要因素,研究景观格局对流域水文过程的影响可以为流域水资源管理和合理利用提供科学依据。以湖南省长沙县金井流域为例,利用2010—2014年实测水文、气象资料和土地利用遥感图,基于Pearson相关分析和多元线性逐步回归模型,分析流域景观格局对水文过程(河川径流与基流)的影响。结果表明:(1)流域河川径流流量季节性波动剧烈,而基流流量的季节性变化相对较小;(2)流域景观格局显著影响水文过程,平枯水期河川基流量与香农多样性指数(SHDI)、斑块密度(PD)和边界密度(ED)呈显著正相关,与蔓延度指数(CONTAG)、最大拼块面积所占景观面积比例(LPI)、聚集指数(AI)和斑块凝聚度(COHESION)呈显著负相关(P<0.05);(3)全年和平枯水期流域河川径流系数和基流量可以用流域内土地利用方式面积比例和景观格局指数预测,对流域景观的合理规划有利于中亚带红壤丘陵区农业流域水资源的科学管理和合理利用。

Landscape is an important factor affecting catchment hydrological processes and water cycling. The study on how landscape affects hydrological processes in a catchment may provide some scientific basis for reasonable water resource management and utilization. A case study was conducted of a catchment, Jinjing catchment of Changsha County, Hunan Province, making use of the hydrological and meteorological data measured during 2010-2014 and the remote-sensing lan-duse maps of that period to analyze effects of the landscape pattern of the catchment on hydrological processes （ i. e. river runoff and base flow）, with the Pearson correlation analysis and multiple linear regression models. Results show as follows：（ 1） volume of the river runoff in the catchment fluctuated drastically and seasonally, while that of the base flow did not vary so much with the season;（ 2） landscape pattern significantly influenced hydrological processes in the catch-ment, especially during the dry and normal period, when volume of the base flow was significantly and positively related to Shannon′s diversity index, patch density, and edge density, but negatively to contag index, largest patch index, aggrega-tion index, and cohesion index（ P〈0. 05）;and （ 3） river runoff coefficient and volume of the base flow in a year or during the dry and normal periods can be predicted from proportions of land use types and landscape patterns in area. Therefore, rational landscape planning of the catchment based on the prediction will help scientific management and reasonable utili-zation of the water resources in central subtropical hilly agricultural catchments.