论文中文题名: | 黑土地侵蚀沟损毁耕地的机理与空间分异规律 |
姓名: | |
学号: | 22209226110 |
保密级别: | 公开 |
论文语种: | chi |
学科代码: | 085700 |
学科名称: | 工学 - 资源与环境 |
学生类型: | 硕士 |
学位级别: | 工程硕士 |
学位年度: | 2025 |
培养单位: | 西安科技大学 |
院系: | |
专业: | |
研究方向: | 土壤侵蚀及其环境效应 |
第一导师姓名: | |
第一导师单位: | |
论文提交日期: | 2025-06-12 |
论文答辩日期: | 2025-05-23 |
论文外文题名: | Mechanisms and spatial differentiation patterns of farmland damage caused by gully erosion in the Black Soil Region |
论文中文关键词: | |
论文外文关键词: | Songnen typical black soil region ; Gully erosion ; Grain yield ; Damaged farmland ; Prediction model |
论文中文摘要: |
东北黑土地是我国粮食生产的“稳压器”和“压舱石”,目前面临严峻的侵蚀沟损毁耕地问题,侵蚀沟发育造成耕地面积减少,阻碍机械化农业生产,成为我国黑土地保护中的关键挑战之一。对侵蚀沟损毁耕地的机理、预测模型和空间分布规律的系统认识,是应对沟毁耕地威胁的关键科学问题。本研究以松嫩典型黑土区为研究区,基于实地调查与采样、无人机遥感调查和亚米级卫星影像调查为主要方法,从坡面、小流域和区域三个尺度研究浅沟和切沟损毁耕地问题,明确了坡面尺度侵蚀沟发育对耕地面积和作物产量的影响规律,揭示了侵蚀沟损毁耕地的机理,构建了小流域浅沟和切沟损毁耕地面积预测模型,结合研究区大量抽样单元的侵蚀沟调查结果,完成松嫩典型黑土区浅沟和切沟损毁耕地面积比例的空间格局和驱动因子分析。为进一步黑土地侵蚀沟治理策略优化提供理论与方法支撑。研究主要得出以下结论: (1)通过对典型黑土区小流域浅沟和切沟各3条共计12个横断面的114个采样点的分析,得出侵蚀沟发育影响下损毁耕地的机理。大豆和玉米产量与土壤紧实度和容重呈显著负相关,与平均重量直径(MWD)、黏粒和饱和导水率显著正相关,与有机质、全氮、全磷和全钾显著正相关。浅沟发育使自沟底向外围3 m处土壤容重和紧实度增加,黏粒、饱和导水率和MWD降低,有机质、全氮、全磷和全钾显著下降。切沟发育使沟底及距沟边外围5 m处土壤物理化学性质降低。浅沟发育导致自沟底向外围3 m处的大豆和玉米植株性状和产量明显降低,坡上位置自沟底向外围3 m范围内大豆和玉米产量分别下降36.85%和14.35%,并且造成坡中和坡下位置自沟底向外围1m处大豆和玉米产量绝收,坡中和坡下位置较坡上更为严重,大豆产量下降较玉米更严重;切沟发育使沟底及距沟边外围8 m处大豆和玉米植株性状和产量下降,使沟底及距沟边外围3m范围大豆和玉米产量绝收,距沟边外围4 m至8 m范围大豆和玉米产量分别下降约45.19%和45.26%。 (2)基于对典型黑土区20个小流域无人机遥感调查和实地调查结果研究发现。典型小流域浅沟和切沟损毁耕地宽度由侵蚀沟本身宽度及周围一定范围共同构成,浅沟损毁耕地宽度是沟宽的2.21倍,切沟损毁耕地宽度为沟宽加抹牛地范围,后者通常为两侧各3-4 m;浅沟损毁耕地面积与浅沟长度存在良好线性关系,以浅沟长度(GL)为主要参数,构建的浅沟损毁耕地面积(DFA)预测模型为DFA=1.15GL,纳什系数(NSE)为0.89;切沟损毁耕地面积(DFA)与切沟长度(GL)和切沟面积(GA)的关系模型为DFA=7.64*GL+GA,模型NSE为0.96。 (3)在松嫩典型黑土区21.2万km2范围内基于亚米影像调查了853个抽样单元,明确了区域尺度浅沟和切沟损毁耕地面积比例及其空间分异规律。浅沟损毁耕地面积比例占侵蚀沟损毁耕地总面积的5.27%,切沟占94.73%;侵蚀沟损毁耕地比例较高的地区主要分布在东北部的漫川漫岗地区和东南部的(四平东北部至长春东北部一带),浅沟损毁耕地比例较大的地区在东北部的漫川漫岗地区,切沟在东北部的漫川漫岗地区和东南部的(四平东北部至长春东北部一带)。浅沟和切沟损毁耕地面积比例主要受坡度和坡长因子影响,坡度和坡长与高程、土壤可蚀性、年均降雨量和归一化植被指数因子交互明显增强对浅沟和切沟损毁耕地面积比例空间分异性解释力。 |
论文外文摘要: |
The black soil region of Northeast China serves as the "stabilizer" and "ballast" of the country's grain production. However, it is currently facing a severe challenge of farmland degradation caused by gully erosion. The development of gullies not only reduces the area of arable land but also hinders mechanized agricultural production, becoming one of the key challenges in black soil conservation efforts. A systematic understanding of the mechanisms, prediction models, and spatial distribution patterns of farmland damaged by gully erosion is a critical scientific issue for addressing this threat. This study focuses on the typical black soil region of the Songnen Plain. Utilizing field surveys and sampling, UAV-based remote sensing investigations, and sub-meter resolution satellite imagery as primary methods, the research examines the issue of farmland loss due to ephemeral and permanent gullies across three spatial scales: slope, small watershed, and regional. The study clarifies the impact patterns of gully development on arable land area and crop yield at the slope scale, the underlying mechanisms of gully-induced farmland degradation were revealed. constructs predictive models for farmland loss caused by ephemeral and permanent gullies at the small watershed scale, and, based on extensive gully survey data from numerous sampling units, analyzes the spatial patterns and driving factors of farmland loss ratios in the typical black soil region of the Songnen Plain. The results provide theoretical and methodological support for optimizing gully erosion control strategies in black soil areas. The main conclusions are as follows: (1) Based on the analysis of 114 sampling points across 12 cross-sections from three ephemeral gullies and three permanent gullies in small watersheds of the typical black soil region, the mechanisms of farmland degradation under gully development were identified. Soybean and maize yields were found to be significantly negatively correlated with soil compaction and bulk density, and significantly positively correlated with mean weight diameter (MWD), clay content, and saturated hydraulic conductivity, as well as with soil organic matter, total nitrogen, total phosphorus, and total potassium contents. Ephemeral gully development led to increased soil bulk density and compaction, along with reductions in clay content, saturated hydraulic conductivity, and MWD within 3 meters from the gully bottom, accompanied by marked declines in soil organic matter and nutrient contents. These effects were more pronounced at middle and lower slope positions compared to the upper slope. Permanent gullies exhibited similar patterns, with increased bulk density and compaction at the gully bottom and within 5 meters from the gully edge, along with significant decreases in soil physical and chemical properties. In terms of crop traits, ephemeral gullies caused notable reductions in soybean and maize plant characteristics-such as root density, aboveground and belowground biomass, plant density, stem diameter, and height-within 3 meters from the gully bottom. Permanent gullies negatively impacted these traits within 8 meters from the gully edge. Yield reductions under ephemeral gully development were evident: at upper slope positions, soybean and maize yields dropped by 36.85% and 14.35%, respectively, within 3 meters from the gully bottom. Total crop failure occurred within 1 meter at the middle and lower slope positions. In the 1-3 meter range, yields at the middle slope position decreased by 66% (soybean) and 36.6% (maize), while at the lower slope position the reductions were 66.8% and 16%, respectively-indicating a more severe impact on soybean than on maize. Permanent gully development caused complete crop loss within 3 meters from the gully edge, and yields dropped by approximately 45.19% (soybean) and 45.26% (maize) in the 4–8 meter range. (2) Based on UAV remote sensing and field survey results from 20 small watersheds in the typical black soil region, it was found that the width of farmland damaged by ephemeral and permanent gullies consists of both the gully width itself and a certain adjacent buffer zone. The width of farmland damaged by ephemeral gullies was 2.21 times the gully width, while for permanent gullies, the damaged width comprised the gully width plus the trampling area on both sides-typically extending 3-4 meters on each side. There was a strong linear relationship between the damaged farmland area (DFA) caused by ephemeral gullies and the gully length (GL). A prediction model was developed with gully length as the main parameter: DFA = 1.15 × GL, with a Nash–Sutcliffe efficiency (NSE) of 0.89. For permanent gullies, a model incorporating both gully length (GL) and gully area (GA) was established: DFA = 7.64 × GL + GA, with an NSE of 0.96. (3) Based on sub-meter satellite imagery, a total of 853 sampling units were investigated across the 212,000 km² Songnen typical black soil region to quantify the proportion and spatial variation of farmland area damaged by ephemeral and permanent gullies at the regional scale. The area of farmland damaged by ephemeral gullies accounted for 5.27% of the total gully-induced farmland loss, while permanent gullies contributed 94.73%. Regions with higher proportions of gully-induced farmland loss were mainly concentrated in the northeastern Manchuan-Mangang area (including northwestern Harbin, central and northern Suihua, and the border between northeastern Qiqihar and Heihe) and the southeastern zone (stretching from northeastern Siping to northeastern Changchun). Areas with a higher proportion of farmland damage caused by ephemeral gullies were mainly located in the northeastern Manchuan-Mangang region, while permanent gully damage was concentrated in both the northeastern Manchuan-Mangang region and the southeastern Siping-Changchun corridor. The proportions of farmland area damaged by both ephemeral and permanent gullies were primarily influenced by slope gradient and slope length. Furthermore, interactions between slope-related factors and elevation, soil erodibility, mean annual precipitation, and the Normalized Difference Vegetation Index (NDVI) significantly enhanced the explanatory power of the spatial heterogeneity of farmland damage. |
中图分类号: | S157 |
开放日期: | 2025-06-26 |