Temporal and spatial variation and prediction of water yield and water conservation in the Bosten Lake Basin based on the PLUS-InVEST model

To comprehensively evaluate the alterations in water ecosystem service functions within arid watersheds,this study focused on the Bosten Lake Basin,which is situated in the arid region of Northwest China.The research was based on land use/land cover(LULC),natural,socioeconomic,and accessibility data,utilizing the Patch-level Land Use Simulation(PLUS)and Integrated Valuation of Ecosystem Services and Tradeoffs(InVEST)models to dynamically assess LULC change and associated variations in water yield and water conservation.The analyses included the evaluation of contribution indices of various land use types and the investigation of driving factors that influence water yield and water conservation.The results showed that the change of LULC in the Bosten Lake Basin from 2000 to 2020 showed a trend of increasing in cultivated land and construction land,and decreasing in grassland,forest,and unused land.The unused land of all the three predicted scenarios of 2030(S1,a natural development scenario;S2,an ecological protection scenario;and S3,a cultivated land protection scenario)showed a decreasing trend.The scenarios S1 and S3 showed a trend of decreasing in grassland and increasing in cultivated land;while the scenario S2 showed a trend of decreasing in cultivated land and increasing in grassland.The water yield of the Bosten Lake Basin exhibited an initial decline followed by a slight increase from 2000 to 2020.The areas with higher water yield values were primarily located in the northern section of the basin,which is characterized by higher altitude.Water conservation demonstrated a pattern of initial decrease followed by stabilization,with the northeastern region demonstrating higher water conservation values.In the projected LULC scenarios of 2030,the estimated water yield under scenarios S1 and S3 was marginally greater than that under scenario S2;while the level of water conservation across all three scenarios remained rather consistent.The results showed that Hejing County is an important water conservation function zone,and the eastern part of the Xiaoyouledusi Basin is particularly important and should be protected.The findings of this study offer a scientific foundation for advancing sustainable development in arid watersheds and facilitating efficient water resource management.

基于MSPA和MCR模型的图木舒克市生态安全格局构建

文章以新疆图木舒克市为研究区,对1998-2018年土地利用结构进行分析,通过形态学空间分析(MSPA)和景观指数法,识别生态源地,结合土地利用类型、海拔、坡度、增强型植被指数构建综合阻力面,采用最小累积阻力模型(MCR)识别生态廊道构建生态网络,进而构建其生态安全格局。结果表明:在1998-2018年这时间段中,图木舒克市土地利用类型变化特点表现为"两增两减两稳定"。MSPA景观类型在西南部最为集中,核心区面积有减少趋势,从景观连通性计算结果得出,研究区内14块核心区可以作为生态源点,同时在各个源点之间存在16条重要廊道以及64条一般廊道;廊道分布多且景观结构较好,区内廊道少、重要性低且景观结构有待改善;由生态源地、生态阻力面、生态廊道和生态源点共同组成研究区生态安全格局。研究结果将为图木舒克市环境保护与建设工作提供科学依据。

基于四种水体指数的艾比湖水面提取及时空变化分析

以Landsat5/7/8系列遥感影像为数据源,利用归一化差异水体指数(Normalized difference water index,NDWI)、改进的归一化差异水体指数(Modified normalized difference water index,MNDWI)、自动水体指数(Automated water extraction index,AWEI)、改进的自动水体指数(Modified automated water extraction index,MAWEI)提取艾比湖水体,建立混淆矩阵对4种水体指数提取结果进行对比分析,利用精度最高指数提取艾比湖面积并通过动态度分析湖泊面积变化趋势,同时对艾比湖面积变化的驱动因素进行分析。结果表明:MAWEI指数精度最高,精度达到95%以上,Kappa系数>0.94。2000—2003年期间,艾比湖面积从768.93 km^(2)增加至982.27 km^(2),湖泊面积增加27.74%、动态度为9.24%;2003—2014年期间,湖泊面积减至447.08 km^(2),湖泊面积缩减54.48%、动态度为-4.95%;2014—2018年期间,湖泊面积再次增加至852.77 km^(2),湖泊面积增加90.74%、动态度为22.68%;2018-2020年湖泊面积减至593.79 km^(2),湖泊面积缩减30.36%、动态度为-15.18%,总的来说近20 a艾比湖面积变化呈现先扩张再退缩的趋势。湖泊面积变化与年均降水量呈正相关,与蒸发量呈负相关,与博尔塔拉河和精河径流量呈正相关。水资源的减少及其周围人口、灌溉面积及生产值持续增长引起经济社会总用水量的激增,对湖泊面积变化产生一定的影响。研究成果对艾比湖生态环境保护有一定参考意义。