摘要：
Infiltration is the process of water entering into, and routings through, the subsurface. It has a profound impact on hillslope and catchment runoff. However, because of the hidden and complex subsurface structures, our understanding of rainfall-related infiltration and how it partitions along a topographic gradient remains challenging. In this study, we used two years of field observations of volumetric soil moisture at 25 combinations of topographic positions and soil depths along a steep subtropical forested hillslope. The lateral partition patterns of infiltration and its control factors were investigated based on a new index, percentage of soil water storage increment at each site to all hillslope sites during a rainfall event (PWSI). Our results showed that the active soil layer involved in hillslope lateral flow was distributed within the depths of 10–40 cm. In deep soil depths (i.e., 40–80 cm), lateral flow was more evident under wet initial moisture conditions than under dry initial moisture conditions, whereas rainfall characteristics had a relatively weak effect on it. Unexpectedly, we found the variability of infiltration partitioning remained high in the deeper soil layers. Among the soil properties, sand, bulk density, n, KS, and SOM were conducive to infiltration, whereas clay had the opposite effect. The dominant factors controlling the lateral partition patterns of infiltration across soil depths were sand in the depths of 0–10 cm, topographic gradient in depths of 10–40 cm, and n (parameter of soil retention curve) in the depths of 40–80 cm. Findings of this study reveal the infiltration partitioning indices were useful to quantitatively describe the distribution patterns of infiltration after rainfall events at the hillslope, and provide new insights into the detection of hillslope lateral flow, which is valuable for understanding subsurface hydrological processes and improving water resource management in humid mountain ecosystems.
期刊：
Journal of Soils and Sediments,2024年24(1):1-16 ISSN：1439-0108
通讯作者：
Liu, Muxing;Yi, J
作者机构：
[Yi, Jun; Lu, Shiguo; Liu, Muxing; Zhang, Hailin; Liu, MX; Wang, Weijie] Cent China Normal Univ, Key Lab Geog Proc Anal & Simulat Hubei Prov, Wuhan 430079, Peoples R China.;[Yi, Jun; Lu, Shiguo; Liu, Muxing; Zhang, Hailin; Liu, MX; Wang, Weijie] Cent China Normal Univ, Coll Urban & Environm Sci, Wuhan 430079, Peoples R China.;[Wan, Jinhong] Inst Water Resources & Hydropower Res, Beijing 100048, Peoples R China.
通讯机构：
[Yi, J ; Liu, MX] C;Cent China Normal Univ, Key Lab Geog Proc Anal & Simulat Hubei Prov, Wuhan 430079, Peoples R China.;Cent China Normal Univ, Coll Urban & Environm Sci, Wuhan 430079, Peoples R China.
关键词：
Soil infiltration response;Forest conversion;Hillslope hydrology;Humid area
摘要：
PurposeUnderstanding the characteristics of soil infiltration response to rainfall is critical for soil water transport processes and hydrologic modeling. However, little is known about how they vary with forest conversion at different temporal stages (< 20 years) below the rooting zone. Therefore, this study aims to investigate soil infiltration response patterns in different subtropical forest conversion hillslopes, including mature original forest (thick root), young secondary forest (middle root), and very young secondary grassland (fine root), and analyzed the effects of environmental factors on the dynamics of soil infiltration.Materials and methodsSeveral metrics were evaluated to characterize and quantify the nature of these responses by estimating changes in the soil water content, the response time difference between two adjacent soil depths, and infiltration velocities for 1144 infiltration events at 6 locations on the three hillslopes.Results and discussionSoil infiltration responses were similar on both forestland hillslopes, yet significantly different from those on the grassland hillslope. The preferential flow was more evident in the profile of thick-rooted vegetation, and the velocity of the wetting front was faster in the profiles of middle- and fine-rooted vegetation. Topography and root characteristics interact to influence soil infiltration response at the hillslope scale.ConclusionsConversion from thick-rooted forests into fine-rooted grasslands altered the rainfall-related soil infiltration dynamics below the rooting zone. In particular, the occurrence of preferential flow and infiltration rates varied, which helps enhance our understanding of ecohydrological processes in the context of changing land use and hydroclimatic conditions.
摘要：
The global trend of vegetation "greening" in the context of ecological restoration necessitates an urgent assessment of ecosystem services. As essential components of ecosystem services, the hydraulic functions of soil in infiltrating and retaining water following vegetation restoration remain unclear, especially in subtropical mountainous and hilly areas with complex topographies. From 2018 to 2021, soil moisture data collected at five-minute intervals were monitored for three restoration strategies in a hilly catchment of China's Three Gorges Reservoir area. The restoration strategies included planted forest (PF) and natural restoration (naturally regenerated forest, NF; deforested pasture, DP). The soil moisture response to rainfall under these strategies was evaluated using several metrics, including the time difference between peak rainfall intensity and peak soil moisture response (T-p2p), cumulative infiltration, and occurrence frequency of preferential flow (PRF). The results showed that the average soil moisture content (SMC) of PF was significantly (p < 0.05) lower than that of NF and DP in both dry and wet seasons, regardless of upslope or downslope location. However, the topographic position affected the difference in average SMC between DP and NF. At the downslope location, the average SMC of DP (0.39 cm(3) cm(-3)) was significantly higher than that of NF (0.33 cm(3) cm(-3)). Conversely, at the upslope location, the average SMC of DP (0.27 cm(3) cm(-3)) was lower than that of NF (0.30 cm(3) cm(-3)). These findings suggested that PF had a lower amount of soil water storage than NF and DP, which was supported by the lowest cumulative infiltration in PF during storm events. The response of soil moisture to storms in PF (T-p2p = 3.1 h) was slower than that in NF (T-p2p = 1.9 h) and DP (T-p2p = 2.5 h). This was consistent with the lower occurrence frequency of preferential flow in PF (PRF = 19.2 %) than NF (PRF = 39.2 %) and DP (PRF = 32.9 %). Therefore, longer response time and less preferential flow indicated that the PF had a relatively poor soil moisture responsiveness to storm events. Accordingly, this study highlights the insufficiency of afforestation in soil water infiltration and retention compared to natural restoration, meriting consideration when assessing soil hydraulic functions in vegetation restoration areas.
关键词：
biochar;coastal saline soils;polyacrylamide;soil microstructure;water and salt transport
摘要：
Increasing scientific knowledge on the improvement of coastal saline soils is critical for spatially expanding coastal development. Biochar and polyacrylamide (PAM) are popular soil amendments, however, it remains unclear how they affect water and salt transport by regulating soil microstructure characteristics. In this study, we conducted a five-year rice barrel trial and investigated the changes in the aggregates and microstructure of saline soils after adding biochar with three different application rates (B1 = 0%, B2 = 2%, and B3 = 5%, mass ratio) and PAM with three different application rates (P1 = 0%, P2 = 0.4 parts per thousand, and P3 = 1.0 parts per thousand, mass ratio), and simulated the water and salt transport. Results showed that at B1 and B2 treatments, soil mu-CT porosity in 2020 increased by 89.8% and 208.0%, respectively, with respect to that in 2016. The development of soil mesopore structure was promoted at B2 treatments, whereas the P2 and P3 treatments promoted the development of the soil macrostructure. Compared with those of the blank control, soil internal mean water flow rate increased by 22.2% at B2 treatments and 69.2% at P2 treatments, respectively. However, their increases were less pronounced at B3 treatments and the water flow rate decreased by 50.5% at P3 treatments. It might be reasonably attributed to the reason that porous biochar helped the formation of soil pore structure while an excessive amount of biochar blocked soil pores. Furthermore, PAM amendment helped to form soil aggregates while an excessive amount of viscous PAM might block soil pores or form a viscous layer. The time corresponding to the maximum salt concentration was negatively correlated with soil mu-CT porosity (R2 = 0.27) and pore connectivity density (R2 = 0.29). Our findings indicate that appropriate amounts of biochar and PAM can help improve saline soil structure in coastal areas, improve their hydraulic properties, and alleviate salt stress.
摘要：
Inorganic fertilizers are widely used to provide crops with significant amounts of nitrogen (N) and phosphorus (P), but can exacerbate soil carbon (C) limitation and acidification. Crop residues with distinct ecological stoichiometry from inorganic fertilizers can help balance soil ecological stoichiometry and thus increase soil organic matter accumulation. The combined use of inorganic fertilizers and crop residues is expected to alleviate the metabolic limitations of organisms and enhance soil C, N, and P sequestration, hence increasing grain yields. However, the effects of this practice on soil C, N, and P stocks and grain yield remain unclear. In this study, we conducted a meta-analysis of 806 paired data to investigate the impact of crop residue return combined with inorganic fertilizer on soil and grain yield across different land uses (paddy, upland, paddy-upland rotation) and soil profiles (0–60 cm). Our findings indicate that crop residue return significantly enhances soil C (8–13%) stocks across all soil layers, particularly in the topsoil (0–20 cm). Soil N (9%) and P (5%) stocks also increase significantly in the topsoil. In uplands, crop residue return can mitigate soil acidification and increase grain yield (by 7%). Moreover, the soil C and N stocks increase depending on the initial soil pH, C and N levels, and C:N ratio. In contrast, the soil P stock increase depends on rainfall, while the grain yield increase is closely linked to the soil texture and fertilizer rate. Our study highlights that crop residue return can increase topsoil C, N, and P stocks, which can benefit crop growth and environmental mitigation efforts. Furthermore, this practice can increase C stocks in deeper soil horizons (below 20 cm), providing a long-term solution to mitigate climate change.
期刊：
Journal of Soil Science and Plant Nutrition,2023年23(4):6813-6826 ISSN：0718-9508
通讯作者：
Yi, Jun;Zhang, HL
作者机构：
[Zhang, HL; Li, Shenglong; Nan, Xin; Liu, Muxing; Yi, Jun; Yi, J; Fei, Yuanhang; Xu, Tianxiang; Nie, Hanjiang; Hu, Kang; Ren, Qian; Zhang, Hailin] Cent China Normal Univ, Hubei Prov Key Lab Geog Proc Anal & Simulat, Wuhan 430079, Peoples R China.;[Liu, Xiaoli] Chinese Acad Sci, Inst Soil Sci, Nanjing 210008, Peoples R China.
通讯机构：
[Yi, J; Zhang, HL ] C;Cent China Normal Univ, Hubei Prov Key Lab Geog Proc Anal & Simulat, Wuhan 430079, Peoples R China.
关键词：
Soil Moisture;Rainfall;Land use Types;Soil Properties;Soil Water Storage
摘要：
Purpose Studying the response of soil moisture (theta) to rainfall is highly significant for comprehending water transport and balance. Nevertheless, the response of theta to rainfall in pristine forest land and farmland after forest reclamation in the Chinese red soil region is rarely compared.Methods In this study, the theta dynamics and the response characteristics of theta to rainfall in upland field (UF), paddy field (PF), and forest land (FL) were revealed, with continuous and high-frequency theta monitoring data at 5, 10, 20, 40, and 70 cm depths, respectively.Results The results showed that the average theta in PF (0.418 cm(3) cm(-3)) was much higher than that in UF (0.317 cm(3) cm(-3)) and FL (0.291 cm(3) cm(-3)). Meanwhile, the longest lag time (16.8 h) and largest required rainfall amount (16.4 mm) for triggering theta response (RRSR) were observed in FL as compared with UF (11.3 h, 10.2 mm) and PF (12.6 h, 8.7 mm). The maximum increment of theta was significantly positively correlated with the rainfall amount (P < 0.01). The RRSR exhibited significant negative correlations with root density, saturated hydraulic conductivities, and the soil pores content with a diameter > 0.1 mm (P < 0.01). Furthermore, the cumulative increment of soil water storage in FL (190.1 mm) was larger than that in UF (160.6 mm) and PF (143.8 mm).Conclusions The land use conversion from FL to UF and PF reduced the rainfall infiltration capacity and may increase runoff potential.
作者机构：
[Liu, Ji; Liu, Muxing; Zhang, Hailin; Yi, Jun] Key Lab Geog Proc Anal & Simulat, Wuhan 430079, Hubei, Peoples R China.;[Liu, Ji; Wang, Qiuyue; Liu, Muxing; Zhang, Hailin; Yi, Jun] Cent China Normal Univ, Coll Urban & Environm Sci, Wuhan 430079, Peoples R China.;[Hu, Wei] New Zealand Inst Plant & Food Res Ltd, Private Bag 4704, Christchurch 8140, New Zealand.
通讯机构：
[Jun Yi] K;Key Laboratory for Geographical Process Analysis & Simulation, Hubei Province, Wuhan, 430079, China<&wdkj&>College of Urban and Environmental Sciences, Central China Normal University, Wuhan, 430079, China
关键词：
Volumetric soil water content;Wavelet analysis;Significant coherence area;Time scale;Vegetation type;Slope position
摘要：
Clarifying the mechanisms governing volumetric soil water content (VSWC) dynamics in soil profiles is essential, as it can help to elucidate soil water transport processes and improve the prediction accuracy of soil hydrological processes. Using Spearman's rank correlation and wavelet coherence analysis methods, similarity in soil profile VSWC dynamics and factors governing VSWC soil profile dynamics in upslopes and downslopes under three vegetation types (evergreen forest [EG], secondary deciduous forest mixed with shrubs [SDFS], and deforested pasture [DP]) at different time scales (hourly, daily, weekly, and monthly) and in different seasons were analyzed. The results revealed significant similarity in the VSWC of different soil depths (P < 0.01), with the similarity decreasing in accordance with the increment in soil depth. Greater VSWC similarity was found in EG than SDFS and DP sites and in upslope than downslope areas at both forest sites. The average significant coherence area (SCA) of VSWC similarity among surface and deep soil layers varied with the time scale, which was in the order of monthly (58.6%) > weekly (42.8%) > daily (21.8%). The effects of soil properties (e.g., texture, saturated hydraulic conductivity), rainfall, and potential evapotranspiration (ETp) on VSWC similarity were related to the time scale and season in which VSWC monitoring took place. Soil properties had apparent effects on VSWC similarity at longer time scales (i.e., monthly), with a high SCA. In contrast, the effects of rainfall and ETp on VSWC similarity were concentrated at weekly and daily scales, with a relatively low SCA. Rainfall and ETp dominated VSWC dynamics in the summer and fall, respectively. These results imply the use of measured VSWC at one soil depth to predict the VSWC at other soil depths was a reliable method. While the in-fluence of time scale effects and seasonal variations on prediction accuracy of VSWC should be considered. ](c) 2022 International Research and Training Center on Erosion and Sedimentation, China Water and Power Press, and China Institute of Water Resources and Hydropower Research. Publishing services by Elsevier B.V. on behalf of KeAi Communications Co. Ltd. This is an open access article under the CC BY -NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
作者机构：
[Liu, Haimeng; Li, Xiangqiang; Liu, Muxing; Liu, Jingyi] Cent China Normal Univ, Coll Urban & Environm Sci, Wuhan 430079, Peoples R China.;[Li, Xiangqiang; Liu, Muxing] Key Lab Geog Proc Anal & Simulat Hubei Prov, Wuhan 430079, Peoples R China.;[Yang, Mengqi] Guangzhou Inst Geog, Key Lab Guangdong Utilizat Remote Sensing & Geog I, Guangdong Open Lab Geospatial Informat Technol & A, Guangzhou 510070, Peoples R China.;[Long, Liangfu] Univ Elect Sci & Technol China, Zhongshan Inst, Dept Tourist Management, Zhongshan 528400, Peoples R China.
关键词：
intangible cultural heritage;spatial distribution;influencing factors;Geodetector;Three Gorges Reservoir Area
摘要：
Intangible cultural heritage (ICH) represents the outstanding crystallization of human civilization and it has received extensive attention from scholars in various countries. Studying the spatial distribution and influencing factors of ICH in the Three Gorges Reservoir Area can help to improve the protection and utilization of ICH. Using quantitative statistical analysis methods, GIS spatial analysis methods, and Geodetector, we analyzed the level structure (provincial and national levels), category structure (ten categories), and spatial distribution of 509 national and provincial ICH items in the Three Gorges Reservoir Area and then explored their influencing factors. We concluded that: (1) The structural characteristics of ICH vary significantly, and the level structure is dominated by provincial ICH items; the category structure is complete and mainly includes traditional skill and traditional music. (2) The spatial distribution of ICH in the Three Gorges Reservoir Area is dense in the west and sparse in the east, with a pattern of "one main core, three major cores, and two minor cores". There are large differences in the degree of concentration of ICH at the county level; different categories of ICH have different distribution densities and concentration areas. Yuzhong District, Shizhu County, and Wanzhou District are dense areas of distribution for different categories of ICH. (3) The influences of different factors on the spatial distribution of ICH in the Three Gorges Reservoir Area vary greatly. Socioeconomic and historical-cultural factors are more influential than natural geographic factors, among which economic development, culture, and ethnicity are the most influential, but the interaction between the two dimensions of natural geography and socioeconomic and historical culture has a more significant influence on the spatial distribution of ICH than single-dimensional factors. (4) Proposals for optimizing the spatial layout, protection, and development of ICH in the Three Gorges Reservoir Area are provided from the perspectives of culture and tourism integration and sustainable development.
作者机构：
地理过程分析与模拟湖北省重点实验室 武汉 430079;华中师范大学城市与环境科学学院 武汉 430079;[张海林; 卢世国; 宋兴敏; 易军; 刘目兴] Key Laboratory for Geographical Process Analysis ＆ Simulation, Hubei Province, Wuhan, 430079, China, College of Urban and Environmental Sciences, Central China Normal University, Wuhan, 430079, China
通讯机构：
[Yi, J.] K;Key Laboratory for Geographical Process Analysis ＆ Simulation, Hubei Province, China
作者机构：
[Peng, Feifei; Liu, Muxing; Li, Xiran] Cent China Normal Univ, Coll Urban & Environm Sci, Key Lab Geog Proc Anal & Simulat Hubei Prov, Wuhan 430079, Peoples R China.;[Yao, Yitong] Univ Paris Saclay, CEA CNRS UVSQ, LSCE IPSL, Lab Sci Climat & Environm, F-91191 Gif Sur Yvette, France.;[Yin, Guodong] Beijing Normal Univ, Coll Water Sci, Beijing Key Lab Urban Hydrol Cycle & Sponge City, Beijing 100875, Peoples R China.
关键词：
drought;resistance;resilience;needleleaf forests;broadleaf forests;northern China
摘要：
Drought can weaken forest activity and even lead to forest mortality, and the response of different forest types to drought can be diverse. Deciduous broadleaf forest (DBF) and deciduous needleleaf forest (DNF) are two of the majority forest types in northern China. In this region, a severe drought event happened in 2002. However, due to the lack of data, the spatio-temporal characteristics of the ecosystem stability of different forest types here remain unclear. In this study, we used a machine learning approach (model tree ensemble, MTE) to drive fluxsite gross primary productivity (GPP), combined with remote sensing-based GPP and a vegetation index data (EVI), to analyze the spatial and temporal characteristics of resistance and resilience of DNF and DBF in northern China during and after the 2002 drought. The results showed that the DBFs were more acclimatized to the drought, while the resistance and resilience of DNF and DBF were diverse under different consecutive drought events. These results could be suggestive for forest conservation and vegetation modeling.
作者机构：
[Zhang, Hai-Lin; Yi, Jun; Bai, Yu-Shi; Liu, Mu-Xing] Hubei Prov Lab Geog Proc Analyzing & Modeling, Wuhan 430079, Peoples R China.;[Zhang, Hai-Lin; Yi, Jun; Bai, Yu-Shi; Liu, Mu-Xing] Cent China Normal Univ, Coll Urban & Environm Sci, Wuhan 430079, Peoples R China.;[Liu, Mu-Xing] Cent China Normal Univ, Res Inst Sustainable Dev, Wuhan 430079, Peoples R China.
通讯机构：
[Liu, Mu-Xing] H;[Liu, Mu-Xing] C;Hubei Prov Lab Geog Proc Analyzing & Modeling, Wuhan 430079, Peoples R China.;Cent China Normal Univ, Coll Urban & Environm Sci, Wuhan 430079, Peoples R China.;Cent China Normal Univ, Res Inst Sustainable Dev, Wuhan 430079, Peoples R China.
关键词：
Soil water content;Temporal stability;Representative location;Hillslope hydrology;Temporal period;Three Gorges region
摘要：
Soil water content (SWC) plays a crucial role in simulating hydrological process, guiding reforestation and controlling soil erosion in mountainous regions. Spatial-temporal variability of SWC increases the difficulty of quantifying SWC pattern in the prediction of soil moisture. Temporal stability analysis of SWC can reduce the labor consuming and simplify the costly field monitoring. This study aimed to evaluate the temporal stability of SWC at hourly, daily and monthly temporal periods and its controlling factors at a hillslope in the Three Gorges region. The SWC of five soil depths was monitored at 5 topographic locations (toe, lower, middle, upper and top slope positions) along a 170 m hillslope in the Three Gorges region (110°04′ ∼112°04′ E, 29°53′∼31°34′ N), Yichang City, Hubei Province, China from May 4th, 2018 to May 3rd, 2019. The results showed that the coefficient of variation of SWC ranged from 4% to 49%, which increased with rising soil depth within 40 cm but thereafter decreased. However, the high Spearman’s rank coefficients (P<0.05) indicated strong temporal stability at three temporal periods. The representative locations (RLs) varied in the different soil depths, which were toe, upper and middle slope positions at 0∼40, 40∼60 and 60∼80 cm depths of the investigated hillslope, respectively. Saturated hydraulic conductivity served as a dominant factor controlling the temporal stability of SWC. The result advances our thorough understanding of hydrology and soil water resource in the Three Gorges region.
