[关键词]
[摘要]
为探究自然因素和人类活动对水域景观格局演变产生的影响,以水域空间演变为主线,通过空间计算、景观 指数分析和统计分析等,对梁子湖流域 2000—2020 年水域转移状况、空间自相关特征、景观格局变化以及驱动 因子进行研究。结果表明:2000—2020 年梁子湖流域水域面积减少约 21%,减少面积中约 95% 转为耕地,建筑用 地面积增长超 4 倍,约 90% 来自耕地的转入;近 10 年水域空间聚集面积减少约 23%,水域分布关联性正在减弱; 水域景观特征在流域上下游差异显著,上游水域面积和形状基本稳定,聚集性和连通性均优于下游,下游水域面 积萎缩近一半,阻隔作用明显,岸线趋于规整;降水、气温、GDP、人口以及耕地和建筑用地面积比例解释了水域 景观变化的 54.7%,城镇化进程和农业生产活动是主要影响因子,其中人口增长和耕地开发对水域面积萎缩贡献 更大,GDP 增长和城镇化进程对水域边界复杂度和连通性的影响更明显。研究结果可为梁子湖流域水域景观保 护修复提供参考。
[Key word]
[Abstract]
Landscape?pattern?and?its?changes?are?of?great?importance?to?ecological?processes?and?security?in?basin?or region.?Liangzi?Lake?is?a?typical?well?protected?grassy?shallow?lake?in?China.?It?plays?important?roles?of?flood storage,?water?supply,?gene?pool,?freshwater?products?supply?and?so?on.?However,?due?to?continuous?reclamations for?farmlands?and?urbanization,?problems?related?to?water?area?shrinkage,?ecological?functional?degeneration?and landscape?fragmentation?are?raising?continuously.?Exploring?the?dynamic?changes?of?water?landscape?and?its?driving factors?from?the?perspective?of?landscape?pattern?in?whole?basin?would?obtain?in-deep?understanding?of?landscape characteristics?and?provide?scientific?references?of?Liangzi?Lake?protection?from?basin-wide?perspective. ??????The?methods?of?spatial?analysis,?landscape?metrics?analysis?and?biostatistical?analysis?are?applied?in?this?paper. Taking?water?landscape?as?the?research?object,?transition?matrix?analysis?is?used?to?describe?transitions?between water?area?and?other?types?of?land?use?during?study?phase.?Aggregation?feature?and?outlier?distribution?of?water?area are?studied?through?spatial?autocorrelation?analysis.?Landscape?metrics?analysis?is?used?to?express?the?features?of area, ?shape, ?aggregation ?and ?connectivity ?quantitively, ?while ?redundancy ?analysis ?is ?employed ?to ?seek ?for ?the driving?forces?of?dynamics?changes. ??????From ?2000 ?to ?2020, ?farmland ?area ?remained ?unchanged ?basically, ?while ?water ?area ?showed ?21%?decrease because?of?water?coverage?being?reclaimed?for?use?as?farmlands.?Urban?area?increased?by?more?than?4?times?by means?of?farmlands?transferred?into.?Water?area?clustered?spatially?with?a?weakening?trend.?The?distribution?of?High value?aggregation?and?Low?value?aggregation?in?water?area?got?more?fragmented,?and?the?area?of?Not?Significant type?increased?by?40%?in?last?decade.?PLAND?and?LPI?of?water?area?had?trend?of?increasing?followed?by?trend?of decreasing.?PD?dropped?gradually?with?an?obvious?decline?of?LSI.?There?were?significant?differences?between?upper and?lower?basin?-?PLAND?and?LPI?of?water?area?in?upper?area?were?about?16%?and?14%?respectively,?while?PLAND and?LPI?in?lower?area?decreased?by?more?than?40%?and?60%?respectively.?Shape?of?water?area?in?lower?area?was more?complicated?than?in?upper?area,?and?LSI?of?upper?and?lower?area?declined?by?32%?and?51%?respectively. Aggregation ?and ?connectivity ?in ?upper ?area ?were ?better ?than ?those ?in ?lower ?area. ?Variation ?partitioning ?of redundancy?analysis?shows?the?54.7%?changes?of?water?landscape?are?a?result?of?natural?and?artificial?factors,?of these ?influences, ?24.2%?of ?the ?changes ?coming ?from ?precipitation ?and ?temperature, ?while ?51.6%?coming ?from contribution?of?human?activities,?the?overlapping?part?is?21.0%. ??????From ?2000 ?to ?2020, ?surface ?area ?of ?water ?in ?Liangzi ?Lake ?has ?decreased ?by ?21%?because ?of ?agricultural reclamation ?directly, ?which ?then ?being ?reclaimed ?for ?urbanized ?purposes, ?leading ?to ?4-time ?area ?increases ?of artificial ?surfaces. ?Farmland ?area ?remains ?unchanged, ?water ?area ?decreased ?attributed ?to ?urbanized ?purposes indirectly.?There?is?a?steady?water?area?aggregation?in?whole?basin,?while?the?relevance?of?water?area?in?local?region are?becoming?decreased?or?disappeared.?Micro-water?body?are?disappearing?with?the?tendency?of?decreasing?of complexity?and?irregularity.?Water?area?distribution?tends?to?be?fragmented,?however?significant?differences?present between?upper?and?lower?basin?areas.?There?are?not?much?changes?of?spatial?distribution?of?water?landscape?in?upper basin?area,?but?in?lower?basin?area,?water?area?reduced?by?nearly?half.?Shoreline?tends?to?be?normalized?and?unified with?an?obvious?obstruction?and?cut?of?water?body.?54.7%?of?the?changes?of?water?landscape?are?the?result?of precipitation,?temperature,?population,?GDP?and?area?ratio?of?farmland?and?artificial?surface.?Human?activities?are the?main?factors,?whose?explanatory?power?are?twice?of?natural?factors.?Population?and?farmland?area?rate?make more?contributions?to?the?water?landscape?area,?meanwhile?GDP?and?urbanization?process?have?more?effects?on shape?complexity?and?connectivity.
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[基金项目]