SOIL EROSION, CONSERVATION, AND ECO‐ENVIRONMENT CHANGES IN THE LOESS PLATEAU OF CHINA

Purpose This paper aims to build a theoretical model of the impact of farmers’ adoption behavior of soil and water conservation measures on the agricultural output to analyze the impact of farmers’ adoption behavior of soil and water conservation measures on agricultural output. Design/methodology/approach Based on the field survey data of 808 farmers households in three provinces (regions) of the Loess Plateau, this paper using the endogenous switching regression model to analyze the effect of farmers’ adoption behavior of soil and water conservation measures on agricultural output. Findings Soil erosion has a significant negative impact on agricultural output, and soil erosion has a significant positive impact on farmers’ adoption of soil and water conservation measures. Farmers adopt soil and water conservation measures such as engineering measures, biological measures and tillage measures to cope with soil erosion, which can increase agricultural output. Based on the counterfactual hypothesis, if farmers who adopt soil and water conservation measures do not adopt the corresponding soil and water conservation measures, their average output per ha output will decrease by 2.01%. Then, if farmers who do not adopt soil and water conservation measures adopt the corresponding soil and water conservation measures, their average output per ha output will increase by 12.12%. Government support and cultivated land area have a significant positive impact on farmers’ adoption behavior of soil and water conservation measures. Research limitations/implications The research limitation is the lack of panel data. Practical implications Soil erosion has a significant negative impact on agricultural output, and soil erosion has a significant positive impact on farmers’ adoption of soil and water conservation measures. Farmers adopt soil and water conservation measures such as engineering measures, biological measures and tillage measures to cope with soil erosion, which can increase agricultural output. Social implications The conclusion provides a reliable empirical basis for the government to formulate and implement relevant policies. Originality/value The contributions of this paper are as follows: the adoption behavior of soil and water conservation measures and agricultural output are included into the same analytical framework for empirical analysis, revealing the influencing factors of farmers’ adoption behavior of soil and water conservation measures and their output effects, enriching existing research. Using endogenous switching regression model and introducing instrumental variables to overcome the endogenous problem between the adoption behavior of soil and water conservation measures and agricultural output, and to analyze the influencing factors of farmers’ adoption behavior of soil and water conservation measures and its impact on agricultural output. Using the counter-factual idea to ensure that the two matched individuals have the same or similar attributes, to evaluate the average treatment effect of the behavior of soil and water conservation measures, to estimate the real impact of adaptation measures on agricultural output as accurately as possible and to avoid misleading policy recommendations.

Response of soil erosion to vegetation and terrace changes in a small watershed on the Loess Plateau over the past 85 years

A systematic review of soil erosion in citrus orchards worldwide

ABSTRACTThe Loess Plateau has one of the most serious areas of soil erosion in China; therefore, studying the effect of soil and water conservation measures on the erosion of loess soil slopes is important for land management and agricultural development. This study is based on 5 years of field runoff observations and rainfall data from 2015 to 2019. Correlation and regression analyses were used to study the runoff and sediment production of loess soil and its relationship with rainfall, slope and land use. The results show that > 80% of the erosive rainfall occurs mainly in July to August in the area. Runoff and soil loss from the plots differed substantially, depending on land use, soil conservation measures and slope degree. Bare plots experienced the highest soil loss rate of over 27 t/ha with higher runoff depth, followed by cultivated plots (4.55 t/ha), grass plots (0.43 t/ha), shrub plots (0.35 t/ha) and forest plots (0.13 t/ha). Among the four soil and water conservation measures, the runoff and sediment reduction benefits of forest and shrub plots were the highest. The runoff reduction benefit fluctuated at approximately 0.8, and the benefit of sediment reduction was ≈1. The overall performance was forest > shrubland > grassland > cultivated land > bare land, and the benefits of sediment reduction were greater than those of runoff reduction. Forests had the highest soil retention capacity on slopes from 5° to 25°, and forests on gentle slopes had the best water storage capacity. Shrub plots had the best water storage capacity when they were on steep slopes. Rainfall erosion forces were significantly and positively correlated (p < 0.01) with runoff depth and soil loss, making it the most significant rainfall indicator of sediment production. Under the same rainfall conditions, soil and water conservation measures are still required on bare slopes, land use is the main control factor for slope sediment production, and appropriate land use can greatly reduce the threat of slopes in terms of soil erosion. This study shows that soil and water conservation measures are imperative to prevent runoff and soil loss, especially for bare land without any measures; on steep slopes, a vegetation combination primarily featuring shrubs is expected to achieve greater benefits in reducing runoff and sediment. This study can provide a scientific basis for the management of vegetation measures and the implementation of soil and water conservation measures on loess soil slopes.

Soil erosion is an imperative environmental deterioration almost all over the world, which leads to reduction of crop yield. Present study investigates farmers' views of soil erosion problems and their conservation measures in the <i>Gummara-Maksegnit</i> watershed to understand inter-relationships between perception of farmers' knowledge and soil conservation practices. Data was obtained from a survey of 332 farm households and informal discussions selected by stratified random sampling from upper, middle and lower catchment at <i>Fertamit, Enkri and Dilkana</i> districts respectively. Both open ended and close ended questionnaires were employed to acquire required data. The result revealed that 81% of the local people realize the occurrence of soil erosion in their farm land. Moreover, 67% of the population recognizes the formation of rill forms of soil erosion on their farm land. 45% of the communities perceive soil erosion as primary factor for productivity reduction while 48% of them consider as second cause. Finally, there are several soil conservation measures done by the society living in the watershed. 84% of the population constructed stone bund on their farm land to control soil erosion. Other soil conservation measures like soil bund, draining ditch, tree planting and contour plowing were practiced. The varieties of conservation measures were very limited and incapable to control erosion forms like gully. Therefore it is highly recommended to teach farmers concerning different soil and water conservation measures and its relevance for tackling soil erosion.

&amp;lt;p&amp;gt;The soils are susceptible to water erosion in the hilly and ravine region of the Loess Plateau due to the readily erodible attribute of soils, erosive geomorphology, land use and land cover, and erosive rainfall. The soil and water losses induced by water erosion have the significant on-site impacts on crop growths and yields in this region because of soil nutrient depletion and adverse soil moisture condition. In addition, the crops grown in different land types frequently suffer from the seasonal draught due to climate change, which leads to the decline or failure of crop yield. Therefore, the crop yields and grain production are susceptibly stressed by soil erosion and drought in this region. Soil erosion and draught are the essential issues faced by agriculture production and eco-environment. Alternatively, effective measures of soil and water conservation can incredibly control soil and water losses induced by water erosion, alleviate the influences of draught on crop yields, and sustain grain production in this region. The check dam is one of the widely adopted engineering measures of soil and water conservation in the valleys of the hilly and ravine region on the Loess Plateau. Check dam can play multiple roles in mitigating soil erosion, trapping eroded sediments, regulating runoff and creating the lands in the valleys in the context of water erosion. The check dam can control the soil erosion to some extent because it can raise the basis level of erosion in the valley. The lost sediment and runoff can be trapped by the check dam in a watershed, which can reduce resultant loss rate of soil and water in the outlet of the watershed and mitigate sediment loads in the rive connecting to the watershed. Moreover, the check dam can make sediments or eroded soils deposit so as to develop the relatively flat lands called as the dam-trapped farmland in the valleys. The dam-trapped farmlands along with the terrace lands are regarded as the crucial farmlands due to their excellent farming conditions in this region. Some grain crops, such corn, sorghum, millet or potato, are always grown in the dam-trapped farmlands, among which corn is frequently planted in this kind of farmland. The crop yields of the dam-trapped farmlands have been increasing over the last 60 years. It is evidenced that the yield of corn increased from 2250-3000 kg/ha in 1960s to 12000-15000 kg/ha at present. The corn yield of the dam-trapped farmland is 1.5-2.0 folds of that of the terrace land. The nutrient use efficiency and water use efficiency of corn in the dam-trapped farmland are much higher than those of terrace land. It can be seen that check dam have the powerful function mitigating the losses runoff and sediment, and dam-trapped land can play the critical parts in sustaining grain production and insuring food security in the hilly and ravine region of the Loess Plateau.&amp;amp;#160;&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;&amp;lt;strong&amp;gt;Keywords:&amp;lt;/strong&amp;gt; soil erosion; check dam; dam-trapped farmland; grain production; food security; hilly and ravine region; Loess Plateau&amp;lt;/p&amp;gt;

PDF HTML阅读 XML下载 导出引用 引用提醒 黄土高原流域水沙变化研究进展 DOI: 10.5846/stxb201909121903 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目（41822103，41471094）；中国科学院青年促进会项目（2016040） Changes in streamflow and sediment load in the catchments of the Loess Plateau, China: a review Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:人类活动和气候变化是影响流域水文过程的两大驱动因素，径流输沙是流域水文过程的总体反映，变化环境下径流输沙的变化规律与成因分析是水文学和全球变化研究的热点问题。黄土高原是我国水土流失最严重的地区。20世纪50年代以来，黄土高原地区开展了大规模的生态环境建设和水土流失综合治理，显著改变了流域土地利用和植被覆盖。下垫面条件改变与气候变化综合作用，使得流域水沙情势发生剧变。围绕黄土高原流域水沙变化的时空尺度特征与驱动机制，总结了径流输沙和水沙关系变化特征的研究结果，归纳了径流输沙变化的归因分析方法与人类活动和气候变化影响的贡献分割结果，探讨了气候变化、植被恢复、水土保持工程措施以及流域景观格局对水沙变化的影响机制。未来应加强流域水沙演变的时空尺度特征特别是水沙关系非线性特征的定量研究，阐明极端事件对水沙动态的影响与贡献；开展水沙变化影响机制的多要素综合解析，发展耦合地表覆被动态特征和气候变化的降雨-径流-输沙模型，揭示生态恢复与水沙演变过程互馈机制；开展未来气候变化、社会经济发展和生态建设工程情景下水沙动态的趋势预测，为黄土高原生态综合治理和水资源管理与黄河水沙调控提供策略建议。 Abstract:Human activities and climate change are two critical driving forces of catchment hydrological processes, for which, streamflow and sediment load are the two main indicators. Changing trends and attribution analysis of streamflow and sediment load under changing environments are now the focus of hydrological and global change studies. The Loess Plateau (LP) of China is well known for its severe soil erosion and the heavy sediment load of the Yellow River that flows through it. To control soil erosion in the LP, large ecological restoration construction projects and several soil and water conservation measures have been implemented since the 1950s, which have resulted in extensive land use and vegetation cover changes. These extensive changes in land surface conditions in combination with climate change have dramatically altered the hydrological regime, including streamflow, sediment load, and flow-sediment relationships in the LP. The spatio-temporal variability of streamflow and sediment load, and the dominant mechanisms behind these changes are important issues in the development of strategies for sustainable land and water management in the LP. We reviewed previous studies that documented changes in streamflow, sediment load, and flow-sediment relationships to improve our understanding of these processes. The methods used to separate the impacts of human activities and climate change on streamflow and sediment load and the results obtained in these studies are summarized here. The influence of climate change, vegetation restoration, soil and water conservation measures, as well as catchment landscape patterns on driving changes in streamflow and sediment load are also discussed. Finally, the following further studies are proposed:1) Studying the spatio-temporal patterns in streamflow and sediment load evolution and quantifying the non-linear characteristics of flow-sediment relationships, 2) Demonstrating the effects and contributions of extreme events on streamflow and sediment load dynamics, 3) Conducting comprehensive analyses on the influence of multiple factors on streamflow and sediment load, 4) Developing a coupled rainfall-streamflow-sediment yield model that includes the dynamic characteristics of surface cover and climate change, with the aim of revealing feedback mechanisms between ecological restoration and the evolution of streamflow and sediment load, and 5) Predicting streamflow and sediment load dynamics under future scenarios of climate change, with the added effects of socio-economic development and ecological construction engineering; which is likely to provide suggestions for ecological treatment and water resource management in the LP, and regulation of water and sediment in the Yellow River. 参考文献 相似文献 引证文献

Soil erosion is the main threat to the stability of ecological environment and the harmonious development of society in Shendong Mining Area. The main causes of this threat include the strong interference of natural characteristics and land development. Scientific soil and water conservation measures can coordinate the contradictions among coal economic development, ecological protection, and residents’ prosperity. Based on particle swarm optimization and analytic hierarchy process, the benefit evaluation system of soil and water conservation measures in Shendong Mining Area is established. The weight ratio of three kinds of benefits in Shendong coal mine collapse area is: ecological benefit &gt; social benefit &gt; economic benefit. The conclusion shows that the implementation of the national policy and the effect of mining area management meet the expectation. Therefore, this study provides effective reference and reasonable suggestions for soil and water conservation in Shendong Mining Area. In terms of control measures, bioengineering measures, such as increased coverage of forest and grass as well as reasonable transformation of the landscape pattern of micro landform, can improve the degree of soil erosion control, optimize the land use structure, and improve the land use rate.

Taye A, Megento TL. 2017. The role of indigenous knowledge and practice on water and soil conservation management in Albuko Woreda, Ethiopia. Bonorowo Wetlands 7: 95-107. The objectives of this study were to assess various aspects of indigenous knowledge and practice in water and soil conservation measures introduced in Albuko Woreda/district, South Wollo, Ethiopia, and investigate how farmers have adopted indigenous soil and water conservation measures. This study also aimed to examine farmers' views on land degradation and assess their adoption behavior of soil and water conservation knowledge. The data for the study originated mainly from farmers in the study area. Structured questionnaire survey and focus group discussion methods were applied to collect the necessary information from farm households. A total of 140 heads of families were questioned. The received data was analyzed using descriptive statistics and quantitative and qualitative data analysis. Even though some soil and water conservation methods were introduced to combat land degradation in Ethiopia, adopting these practices remains below expectations. Most farmers preferred soil (stone) bund, water diversion ditch and contour ploughing for soil and water conservation, crop rotation, and mixed cropping for soil fertility amendment measures instead of traditional cutoff drain and fallowing. Farmers faced several constraints in adopting soil and water conservation measures. The main problems related to conservation structures include the source of pests, inconveniency during ox ploughing, reduction of farmland, labor intensiveness, difficulty in implementation, and costliness. In contrast, farmers were knowledgeable about various indigenous soil and water conservation measures but implemented only some of them. They understand the effects of erosion on crop productivity. Finally, farmers need to be trained on the impact of soil erosion and available conservation measures. Information on the ineffectiveness of some traditional conservation measures has to be disseminated among farmers.

Soil and water erosion has long been regarded as a serious environmental problem in the world. Thus, research on reducing soil erosion has received continuous attention. Different conservation measures such as restoring low-function forests, closing hillsides for afforestation, planting trees and grass, and constructing terraces on slope land have been implemented for controlling soil erosion problems and promoting vegetation cover change. One important task is to understand the effects of different conservation measures on reducing water and soil erosion problems. However, directly conducting the evaluation of soil erosion reduction is difficult. One solution is to evaluate the patterns and magnitudes of vegetation cover change due to implementing these measures. Therefore, this research selected Changting County, Fujian Province as a case study to examine the effects of implementing conservation measures on vegetation cover change based on time series Landsat images and field survey data. Landsat images between 1986 and 2021 were used to produce time series vegetation cover data using the Google Earth Engine. Sentinel-2 images acquired in 2021 and Landsat images in 2010 were separately used to develop land cover maps using the random forest method. The spatial distribution of different conservation measures was linked to annual vegetation cover and land cover change data to examine the effects on the change in vegetation cover. The results showed a significant reduction in bare lands and increase in pine forests. The vegetation coverage increased from 42% in 1986 to 79% in 2021 in the conservation region compared with an increase from 73% to 87% in the non-conservation region during the same period. Of the different conservation measures, the change magnitude was 0.44 for restoring low-function forests and closing hillsides for afforestation and 0.65 for multiple control measures. This research provides new insights in terms of understanding the effects of taking proper measures for reducing soil and water erosion problems and provides scientific results for decisionmaking for soil erosion controls. The strategy and method used in this research are valuable for other regions in understanding the roles of different conservation measures on vegetation cover change and soil erosion reduction through employing remote sensing technologies.

The capacity of soil and water conservation measures, defined as the maximum quantity of suitable soil and water conservation measures contained in a region, were determined for the Loess Plateau based on zones suitable for establishing terraced fields, forestland and grassland with the support of geographic information system (GIS) software. The minimum possible soil erosion modulus and actual soil erosion modulus in 2010 were calculated using the revised universal soil loss equation (RUSLE), and the ratio of the minimum possible soil erosion modulus under the capacity of soil and water conservation measures to the actual soil erosion modulus was defined as the soil erosion control degree. The control potential of soil erosion and water loss in the Loess Plateau was studied using this concept. Results showed that the actual soil erosion modulus was 3355 t∙km–2∙a–1, the minimum possible soil erosion modulus was 1921 t∙km–2∙a–1, and the soil erosion control degree was 0.57 (medium level) in the Loess Plateau in 2010. In terms of zoning, the control degree was relatively high in the river valley-plain area, soil-rocky mountainous area, and windy-sandy area, but relatively low in the soil-rocky hilly-forested area, hilly-gully area and plateau-gully area. The rate of erosion areas with a soil erosion modulus of less than 1000 t∙km–2∙a–1 increased from 50.48% to 57.71%, forest and grass coverage rose from 56.74% to 69.15%, rate of terraced fields increased from 4.36% to 19.03%, and per capita grain available rose from 418 kg∙a–1 to 459 kg∙a–1 under the capacity of soil and water conservation measures compared with actual conditions. These research results are of some guiding significance for soil and water loss control in the Loess Plateau.

Since the 1970s, comprehensive control measures on soil erosion in the headwater region of the Loess Plateau have been carried out. Quantitative evaluation of the benefits of soil and water conservation measures during extreme rainstorms is of great significance for the comprehensive management of the catchments. In this study, a systematic modeling methodology for evaluating the effects of soil and water conservation measures on sediment reduction was developed based on a distributed soil erosion model (DSEM). Taking the Chabagou basin in the Loess Plateau as the study area, the tested DSEM was used to simulate soil erosion and sediment yield during an extreme rainstorm under two scenarios, the uncontrolled condition and the controlled condition with soil and water conservation measures implemented. The results showed that DSEM could successfully simulate soil and water losses and evaluate the effects of soil and water conservation measures during extreme storm events. The evaluated results showed that each soil and water conservation measure had the specific function of sediment reduction. And under rainstorm conditions, the effect of engineering measures on sediment reduction was greater than that of forest and grass measures.

Eco-hydrological simulation of soil and water conservation in the Jinghe River Basin in the Loess Plateau, China

The study was carried out 2020-2021 at the Gharat watershed is located in Pindwara district. To evaluate the impact of various biological and physical soil and water conservation (SWC) measures, implemented in the Gharat watershed during 2011-12 in combating minimal land resource use, land degradation caused by soil erosion, and lack of implementation of agriculture technology. Therefore, evaluation is required to determine the success or failure of conservation measures and to alter future planning appropriately. Due to the implementation of the watershed program, arable area increased by 16.56 percent, irrigated area by 53 percent, and additional farm income increased by approximately 17 lakhs, according to data collected through field observation, survey, semi-structured interviews, and field measurements. SWC measures applied in this watershed, cropping intensity and irrigated area increased from 122.12 percent to 137.08 percent, 51ha to 78ha respectively. The understanding and adaption of soil and water conservation strategies has a favorable influence on the overall development of the watershed. Existing SWC measures should be improved for continuing monitoring and extended as part of an integrated strategy to restore damaged regions to their full potential. It provides project planners and managers, programme leaders, and policymakers with details about actual project accomplishments in the format they need.

The Chinese Mollisol region is affected by soil erosion. Soil and water conservation (SWC) measures are effective in preventing these phenomena. However, few studies have systematically reviewed soil erosion and SWC measures in this region. The objectives of this paper were to analyze soil erosion and identify typical SWC measures on hillslopes in this Mollisol region. A literature review and analysis were conducted. Soil erosion is widespread in this region and is dominated by snowmelt and wind erosion in winter and spring, rainfall in summer and wind erosion in autumn. The A-horizon thicknesses and organic matter content of the Mollisol decreased with an increase in the number of years of cultivation. Therefore, controlling soil erosion is a means to protect this precious Mollisol resource. The characteristics of 39 SWC measures used on hillslopes were summarized. Among these measures, the contour ridge, large ridge, minimal tillage with residue mulching, no-tillage, straw returning, slope terrace, ridge belt, and agricultural protection forest approaches were the most typical SWC measures. Furthermore, the new tillage measure of half-ridge planting needs to be examined in future studies. In conclusion, it is of practical significance to select suitable SWC measures for different hillslopes in the Mollisol region.