北洛河上游县域土地利用时空变化及其对水沙的影响  

Spatiotemporal variation of land use in counties of the upper reaches of the Beiluo River and its impact on runoff and sediment

作　　者：樊琳 魏天兴[1,2] 张晓明 缪今典[1,2] 李亦然 Fan Lin;Wei Tianxing;Zhang Xiaoming;Miao Jindian;Li Yiran(School of Soil and Water Conservation,Beijing Forestry University,Beijing 100083,China;Jixian National Forest Ecosystem Observation and Research Station,CFERN/CNERN,Beijing 100083,China;State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin,China Institute of Water Research and Hydropower Research,Beiing 100048,China)

机构地区：[1]北京林业大学水土保持学院,北京100083 [2]山西吉县森林生态系统国家野外科学观测研究站,北京100083 [3]中国水利水电科学研究院流域水循环模拟与调控国家重点实验室,北京100048

出　　处：《北京林业大学学报》2024年第2期95-104,共10页Journal of Beijing Forestry University

基　　金：国家重点研发计划(2022YFF1300801、2022YFF1300401)。

摘　　要：【目的】探究土地利用变化有利于识别水沙变化原因,对流域水土保持及生态保护政策的实施与改进具有指导意义。【方法】以黄土高原北洛河上游为研究区,基于GEE与PIE-Engine平台获取1990—2020年土地利用、植被覆盖度数据,从地类转移、植被覆盖度(FVC)、土地利用强度(LUI)及景观格局(平均斑块面积AREA_MN、聚合度指数AI、最大斑块指数LPI、景观形状指数LSI)4方面描述北洛河上游各县域土地利用情况,并结合水沙数据探究土地利用与水沙的相关关系。【结果】(1)2000年后北洛河上游农田向草地、森林转移,其面积减幅达79.05%,其中“农田→森林”集中分布于吴起县东南部,“农田→草地”在定边县分布最为密集。(2)2000—2020年流域FVC迅速增加,吴起县整体FVC高于定边县同期水平;定边县LUI变化较吴起县存在滞后性,但二者均在2010—2020年间明显下降。(3)2000年前后年径流、输沙减少率分别为46.68%、81.83%;2000—2020年来沙系数0.42小于1990—2000年来沙系数0.80。(4)FVC与水沙量呈显著负相关,森林AREA_MN、AI分别与径流量、输沙量呈显著正相关,森林LPI、LSI与径流量、森林LSI与输沙量呈显著负相关。【结论】北洛河上游水沙与土地利用结构布局关系密切,不同县域地表覆被与用地强度差异明显,在退耕还林(草)驱动下该地区土地总体变化趋势有助于削减径流泥沙。研究结果将为流域土地利用与黄土高原径流泥沙关系研究提供参考。[Objective]The purpose of this study was to investigate the favorability of land use changes in identifying the causes of runoff and sediment variations,providing guiding significance for the implementation and improvement of watershed soil and water conservation and ecological protection policies.[Method]The research selected the upper reaches of the Beiluo River as the study area and utilized the GEE and PIE-Engine platforms to acquire land use and fraction vegetation cover(FVC)data from 1990 to 2020.Descriptions of land use in various counties in the upper reaches of the Beiluo River were conducted from four aspects:land class transitions,FVC,land use intensity(LUI),and landscape pattern(average patch area,AREA_MN;largest patch index,LPI;landscape shape index,LSI;aggregation index,AI).Additionally,the correlation between land use and runoff-sediment was explored by integrating runoff and sediment data.[Result](1)After 2000,there was a shift from farmland to grassland and forests in the upper reaches of the Beiluo River,with a reduction in area by 79.05%.The transition from“farmland to forest”was concentrated in the southeast of Wuqi County,while“farmland to grassland”was most densely distributed in Dingbian County,Shaanxi Province of northwestern China.(2)From 2000 to 2020,the FVC in the basin increased rapidly,with Wuqi County having an overall higher FVC than Dingbian County.The change in land use intensity in Dingbian County lagged behind that of Wuqi County,but both exhibited a significant decreasing trend from 2010 to 2020.(3)Around 2000,the reduction rates of annual runoff and sediment transport were 46.68%and 81.83%,respectively.Coefficient of sediment inflow from 2000 to 2020(0.42)was less than that from 1990 to 2000(0.80).(4)Under the same runoff volume,sediment transport from 2000 to 2020 was much lower than that from 1990 to 2000.FVC showed a significant negative correlation with runoff-sediment,while forest AREA_MN and AI were significantly positively correlated with runoff.Forest LPI,LSI w

关 键 词：北洛河 土地利用强度 植被覆盖度 景观格局 径流泥沙 

分 类 号：S728[农业科学—林木遗传育种] P333[农业科学—林学]