基于图斑精细化管理的国家水土保持重点工程治理效果评估

Evaluation on the effect of National Key Soil and Water Conservation Project based on fine management of map spots

【目的】探讨国家水土保持重点工程实施后治理效果。【方法】以山东省蒙阴县张家村小流域为例,以水土保持基础图斑和效果图斑为单元,基于高分辨率遥感、无人机、移动终端等技术,通过调查测定和野外复核,对比分析了国家水土保持重点工程治理实施前后土地利用、林草植被覆盖、水土保持措施和水土流失状况变化。【结果】①国家水土保持重点工程实施后图斑变化数量共339个,变化面积870.60 hm2,变化方向主要为坡耕地/旱梯田转变为果园,其次为坡耕地变转为旱梯田;②基础年林草覆盖率31.13%,评估年林草覆盖率为45.69%,覆盖度均以中高覆盖(60%~75%)为主,林草覆盖提高率为14.56%;③水土保持措施保存率中,蓄水池保存率最高,为100.00%;谷坊最低,仅为55.56%,其余水土保持措施保存率均在80.00%以上;④评估年较基础年水土流失面积减少了400.39 hm2,水土流失面积消减率23.21%,水土流失治理度为76.78%。【结论】国家水土保持重点工程的实施,明显改善了蒙阴县张家村小流域的生态环境,重点体现为水土流失减少,林草植被覆盖率提高。

[Objective]This study aims to discuss the governance effect of the National Key Soil and Water Conservation Project after implementation.[Method]Taking the small watershed of Zhangjia Village in Mengyin County of Shandong Province as an example,and soil and water conservation in basic spot and effect spot as the unit,the changes of land use,forest and grass vegetation coverage,soil and water conservation measures,and soil and water loss before and after the implementation of the National Key Soil and Water Conservation Project were compared and analyzed through investigation,measurement and field review,based on high-resolution remote sensing,UAV,mobile terminal and other technologies.[Result](1)After the implementation of the project,there were 339 plot changes,covering an area of 870.60 hm2.The change direction was mainly from slope farmland/dry terrace into orchards,followed by slope farmland into dry terrace.(2)The basic annual forest and grass coverage rate was 31.13%,and the assessed annual forest and grass coverage rate was 45.69%. The coverage rate was mainly medium and high (60%–75%), and the improvementrate of forest and grass coverage was 14.56%. (3) The conservation rate of soil and water conservation measureswas the highest in reservoir (100.00%), the lowest in millet workshop (55.56%), and the conservation rate ofother soil and water conservation measures was above 80.00%. (4) The area of soil and water loss reduced by400.39 hm2 in the evaluation year compared with the base year, the reduction rate of soil and water loss was23.21%, and the degree of soil and water loss control was 76.78%. [Conclusion] Through implementation ofthe National Key Soil and Water Conservation Project, the ecological environment in the small watershed ofZhangjia Village in Mengyin County has been significantly improved, which is mainly reflected in the reductionof soil and water loss and the increase of forest and grass vegetation coverage.