The purpose of this study is to explore the mechanism of soil nutrient loss above and below ground in the rocky desertification ecological restoration area of the fault basin. In order to provide an effective reference for soil nutrient loss and agricultural non-point source pollution prevention and control in the faulted rocky desertification area. Taking the rocky desertification area of the fault basin as the research object, different soil-rock ratios were used to simulate three experimental plots of severe, moderate and mild rocky desertification. Simultaneously, different rainfall intensities (25、50、75 and 100 mm/h) were applied to analyze nutrient loss from soil, surface runoff, and subsurface runoff during the early stage of ecological restoration. ①Significant differences were observed in soil nutrient loss characteristics under varying degrees of rocky desertification. In the early stage of restoration, the soil organic matter in the mild, moderate and severe habitat areas decreased by 32.88%, 31.81% and 11.60% respectively compared with the test soil, and the total phosphorus and total nitrogen decreased simultaneously. The total potassium in the mild habitat increased by 17.51%, indicating that vegetation restoration had a significant effect on potassium fixation. ② Surface runoff is the main way of nitrogen and phosphorus loss. When the rainfall intensity increased from 25 mm/h to 100 mm/h, the loss concentration of nitrate nitrogen and ammonia nitrogen in light and moderate habitats increased from 0.42~0.43 mg/L to 0.52 mg/L; the total phosphorus concentration in severe habitats increased from 0.16 mg/L to 0.23 mg/L, but soluble phosphorus and positive phosphorus fluctuated, reflecting that phosphorus migration was regulated by particle adsorption-dissolution balance. ③Nutrient loss via subsurface runoff was affected by both rainfall intensity and rocky desertification degree. When the rainfall intensity reached 50 mm/h, the concentration of nitrate nitrogen in mild habitat reached 1.61 mg/L; when the rainfall intensity increased to 75~100 mm/h, the concentration of nitrogen and phosphorus loss increased regularly, and the total phosphorus concentration in severe habitat increased by 70%. The contribution of vertical runoff to total runoff loss is 20%~35%. ④The amount of nutrient loss driven by surface runoff was 3~4 times that of subsurface runoff, but the proportion of underground loss increased significantly under high rainfall intensity (>75 mm/h). It is suggested that by constructing rattan-grass-shrub composite vegetation (coverage >60%) and deep-rooted plant soil fixation (accounting for >40%), the surface erosion and underground leakage can be reduced synergistically, and the nutrient loss can be reduced by 50%~70%. Studies have shown that the soil nutrient loss in the rocky desertification restoration area of the fault basin is mainly caused by surface runoff, but underground runoff cannot be ignored. In order to effectively prevent and control soil nutrient loss, a variety of measures can be taken, such as constructing a vine-grass-shrub plant community to increase coverage and reduce surface runoff; the use of vegetation roots to fix the soil to prevent nutrient leakage from underground pores, in order to achieve the purpose of reducing soil nutrient loss.

To investigate the soil erosion dynamics in Jiangxi Province, this study conducts a comprehensive analysis of the primary driving factors and their mechanisms by integrating the geodetector method and the Revised Universal Soil Loss Equation (RUSLE) model. Soil erosion data from five time points 2000、2005、2010、2015 and 2020 were selected to assess the influence of each factor on soil erosion, as well as their interrelationships, and to perform sensitivity analyses of soil erosion. The results indicate significant spatial heterogeneity in soil erosion across Jiangxi Province. Overall, the severity of erosion showed a decreasing trend, with a notable reduction in areas experiencing moderate or higher levels of erosion. In the single-factor analysis, vegetation cover and slope emerged as the primary influencing factors, both demonstrated strong explanatory power for soil erosion. The interaction analysis revealed that all factors exhibited either two-factor enhancement or nonlinear enhancement, highlighting the complexity of erosion dynamics. Soil erosion sensitivity in Jiangxi Province was found to be predominantly low, exhibiting a distinct spatial pattern with lower sensitivity in the northern and northwestern regions and higher sensitivity in the eastern and southeastern areas.

The Shiyang River Basin, as a highly representative arid inland river basin in the northwest of China, has long been plagued by the issue of soil erosion control within the basin, which has been a significant obstacle to ecological protection and economic development. How to quantitatively analyze the total amount of soil conservation in the future and enhance the ecological resilience of the Shiyang River Basin has become the focus of sustainable development in the basin. This paper takes the Shiyang River Basin as the research object. By using the FLUS model, it simulates the spatial pattern of land use in the Shiyang River Basin in 2035 under three scenarios: cultivated land protection, natural development, and ecological protection. Combined with the Soil Erosion (SDR) module of the InVEST model, the study predicts the spatiotemporal evolution of soil erosion and soil conservation in Shiyang River Basin in 2035 under the three scenarios. In 2020, the soil retention volume in the Shiyang River Basin was 337 million tons. Under the ecological protection scenario, the soil retention volume was 394 million tons; under the farmland protection scenario, it was 418 million tons; and under the natural development scenario, it was 406 million tons. The soil retention volumes in all three scenarios showed an increasing trend compared with that in 2020. From the perspective of different county-level administrative regions, Tianzhu Tibetan Autonomous County had the highest soil retention capacity at 347.84 tons per hectare per year, while Minqin County had the lowest soil retention intensity at 3.21 tons per hectare per year. There was a significant difference in soil retention capacity among the counties. Slope, precipitation, and elevation had the strongest explanatory power for the spatial heterogeneity of soil retention capacity in the Shiyang River Basin, with q values of 0.679、0.568 and 0.548, respectively. Plant water content had the lowest explanatory power, with a q value of only 0.062. The development status of soil erosion and conservation in Shiyang River Basin from 2020-2035 was quantitatively discussed from different perspectives, and the core driving forces of soil conservation in Shiyang River Basin in the future were revealed, providing a scientific basis for land management policy formulation and soil and water conservation management in Shiyang River Basin.

To clarify the effect of biochar on the N₂O emissions and the economic feasibility of biochar, in the summer corn, set irrigation and carbon amount two factors, including deficit irrigation set full irrigation (F), jointing irrigation (D1) and grain-filling stage irrigation (D2) two levels, carbon set 0 t/hm² (B0), low carbon 15 t/hm² (B15), high carbon 30 t/hm² (B30) three levels. The results show that the average N₂O emission flux of irrigation during the jointing stage and grouting period is reduced by 2.81%~42.74% and 11.78%~15.08% respectively; the jointing stage loss has a negative impact on the yield, and the biochar. The study shows that in the filling period, 50%~60% of the field water supply and the 30 thm-2 biochar can improve the water utilization efficiency and yield of summer corn farmland and reduce N₂O emission. The short-term application of biochar does not have economic benefits, but the economic benefits under the long-term effect need to be further studied.

To investigate the effects of partial substitution of different kinds of manure on soil properties, vegetable yield and nitrogen utilization of facility vegetable land, and to provide theoretical basis for realizing sustainable development of facility vegetable land. A field plot experiment was set up with a total N application of 150 kg/hm², and treatments of no N fertilizer (CK), 100% chemical fertilizer N (CF), pig manure with 30% N substitution (P), chicken manure with 30% N substitution (C), and goat manure with 30% N substitution (S) were set up to analyze the dynamic changes of the soil properties, the distribution of N in the plants and the soil of different depths, the yield, and the utilization of N in the vegetable at the end of the planting period, with Chinese cabbage as the vegetable for test. The dynamic changes of soil properties during the reproductive cycle of vegetables, the distribution of nitrogen in plants and soil at different depths at the end of planting, yield and nitrogen utilization were analyzed. Results indicated that partial replacement of chemical fertilizer with manure could ameliorate the pH of alkaline soil, improve soil water retention capacity, and enhance soil fertility. The pig manure substitution treatment (P) significantly increased soil nitrate nitrogen and total nitrogen content, exhibiting a persistent fertilizer effect; these were 280.63% and 26.18% higher in the topsoil, respectively, compared to CF. The substitution treatment of pig manure, chicken manure and goat manure had significant effect on vegetable yield increase, with the increasing rate of 47.13%, 38.22% and 21.66% compared with CF, respectively. Furthermore, the nitrogen use efficiency indicators—NUE, NAUE, and NPFP—were significantly higher under manure substitution treatments than CF, with pig manure substitution achieving the highest increases of 366.85%, 192.37%, and 47.25%, respectively. Considering the soil environment, vegetable yield, and nitrogen use efficiency indicators, the 30% pig manure substitution treatment (P) was identified as a superior fertilization strategy, offering greater yield advantages and potential for reducing chemical fertilizer application in facility vegetable cultivation systems.

In order to study the effects of using biogas slurry as fertilizer on corn yield, quality and soil properties, a field experiment was conducted in Wangdu County, Baoding City, Hebei Province. The experiment had six treatments, including the control treatment (CK), conventional fertilization (CF), 25% biogas slurry (T1), 50% biogas slurry (T2), 75% biogas slurry (T3), and 100% biogas slurry (T4). The results showed that compared with the conventional fertilization (CF) treatment, using biogas slurry as fertilizer increased the nutrient content in the soil, alleviated soil alkalinity, improved soil water-holding capacity, and the changes were proportional to the concentration of biogas slurry. Compared to CF, the T4 treatment showed a pH reduction of 0.25 units, a 27.1% increase in total nitrogen, a 132.2% increase in alkali-hydrolyzable nitrogen, and a 33.3% increase in organic matter content. Furthermore, short-term rational application of biogas slurry did not cause heavy metal pollution.. The application of biogas slurry increased the content of available nutrients in the soil, which promoted the synthesis of chlorophyll in corn leaves and subsequently promoted the growth of corn, increasing corn yield and improving corn grain quality. Under the experimental conditions of this study, the corn yield and quality increased first and then decreased with the increase in the concentration of fertilizer biogas slurry applied as a top dressing, and the corn crop with the best growth was the T3 treatment (75% biogas slurry, with a top dressing of 45 m³/hm² applied at the jointing stage and the tasseling stage), with a 9.0% increase in grain weight compared with the CF treatment and an 8.5% increase in yield; the corn grain quality of the T3 treatment was also the best, with a 12.1% increase in starch content and an 8.2% increase in crude protein content compared with CF treatment.

In order to explore the reasonable selection of roughness coefficient of concrete lined channel, the prototype observation experiment was carried out with a medium-sized concrete lined channel in cold region as the research object, and the numerical prototype observation experience and achievements of roughness coefficient of lined channel were accumulated. Data on channel flow and water depth from three trapezoidal test channel sections were analyzed, and a relationship surface for the roughness coefficient as a function of flow rate and temperature was established using nonlinear surface fitting. More than 600 groups of numerical simulations were carried out on the experimental canal section by FLUENT, and the fitting relationship formula was verified. The experimental results show that the average roughness coefficient obtained by numerical simulation is 0.015 29, and the average relative error is 2.52%. The R ² values for the fitted models of concrete trapezoidal channel roughness were all above 0.99, indicating a high goodness of fit. The roughness coefficient calculated using the fitted formula is 0.015 80, with an average relative error of 2.80%. The fitted formula can be used for the preliminary selection of roughness coefficient value in engineering design. Combined with numerical simulations, it can provide a reference for the appropriate selection of the roughness coefficient in the initial stage of channel design and guide engineering design.

The current irrigation diversion in farmland is mainly based on simple single threshold drought judgment combined with mechanical switch manual or timed control, and cannot be classified according to soil drought characteristics before irrigation control. Therefore, an intelligent control method for agricultural water conservancy irrigation diversion machinery based on DCNN-SVM is proposed. The proposed method involves real-time collection of soil moisture data from agricultural irrigation areas using moisture sensors. A DCNN-SVM model is constructed, wherein the DCNN extracts features from the soil moisture data, which are then fed into an SVM for soil moisture state classification. Based on the SVM classifier's output, a corresponding irrigation control strategy is determined. This strategy is subsequently converted into specific control signals that are sent to the diversion valve controller to automatically adjust the valve opening, thereby achieving precise control of irrigation water volume. The experiment shows that this method can accurately collect and analyze soil moisture data in the irrigation area of farmland, successfully identify different categories of soil moisture, and accurately control the opening of the diversion mechanical valve of farmland water conservancy irrigation, with an error of no more than 5%. The irrigation amount after diversion control was 52~70 L, which was lower and thus resulted in water savings.

The integrated climate-ecology-hydrology zoning is a critical interdisciplinary research direction in physical geography and environmental resource science, essential for revealing regional interactions among climate change, ecological succession, and hydrological processes. Traditional single-factor zoning approaches inadequately reflect the synergistic effects among environmental elements and their comprehensive impacts on ecological systems. This study establishes an integrated zoning evaluation system for the Yellow River Basin by systematically combining climate, ecological, and hydrological elements through K?ppen climate classification and K-means clustering analysis, incorporating multi-source datasets (1960-2020), including precipitation, temperature, land use patterns, vegetation types, NDVI values, soil classifications, and DEM data. Key findings demonstrate that the K?ppen classification delineates four primary climate zones: the Source Region Polar Zone, Central Arid Zone, Central Cool Temperate Zone, and Eastern Cool Temperate Zone. K-means clustering analysis of ecological indicators (land use, vegetation, NDVI, soil, and DEM) identified seven secondary ecological subregions. Watershed segmentation based on DEM and hydrological networks yielded 72 primary hydrological units. The spatial superposition of these classification schemes ultimately produced 18 integrated climate-ecology-hydrology zones. This integrated zoning framework not only elucidates fundamental patterns of natural environmental differentiation in the Yellow River Basin but also provides a scientific basis for ecosystem management and environmental conservation strategies.

Based on daily meteorological data from 1970 to 2019 at 28 weather stations in Jilin Province, the potential evapotranspiration was calculated using the Penman-Monteith method. The study explored the spatiotemporal distribution of the "evaporation paradox" in Jilin Province and quantitatively investigated its causes by the detrending method. The results show that : ① Under the annual average state, due to the positive contribution of water vapor pressure difference and temperature being greater than the negative contribution of wind speed and sunshine hours, there is no "evaporation paradox" phenomenon in Jilin Province. Spatially, the paradox primarily occurs in the western region, driven by the negative contribution of wind speed, and restrained by the positive contribution of vapor pressure deficit. ② Seasonally, the "evaporation paradox" is evident in summer, while it is less evident in other seasons. In spatial terms, the spring "evaporation paradox" mainly appears in the eastern and western regions, with fewer occurrences in the central region. While in other seasons, the stations exhibiting "evaporation paradox" are mainly located in the western region. ③ The negative contribution of wind speed drives the occurrence of the "evaporation paradox" in spring, autumn, and winter, whereas in summer, it is mainly driven by the negative contribution of sunshine duration. These findings will help deepen the understanding of the hydrological cycle in the region under the context of climate change and provide a scientific reference for the rational development of water resources.

This study uses remote sensing data and the random forest method to extract and analyze the winter irrigation area in Korla City, Peacock River Basin, aiming to provide a theoretical basis for the rational allocation and management of modern water resources in Southern Xinjiang. Using Landsat-8 image data, arable land was divided out by supervised classification method. On the basis of extracting the range of cropland, based on the sample points obtained from field sampling, the historical sample points were obtained through the visual interpretation method, and the indices of MNDWI, NDVI, EVI, GCVI, WGI and NDBI were used as the classification parameters, and the Random Forest Algorithm was applied to identify and extract the cropland irrigation area in 2013, 2015, 2018 and 2022. The results show that the winter irrigated areas of cultivated land in the irrigation area of Korla City in 2013, 2015, 2018, and 2022 were 50 320、47 247、29 560 and 29 340 hm², respectively. The winter irrigated area showed an overall decreasing trend in both spatial and temporal scales. The water resource management system and changes in farmers' cognitive concepts regarding winter irrigation behavior are the main factors affecting this decline.

This study aims to explore the dynamic changes of soil moisture under different sowing dates through field experiments, providing scientific basis for agricultural water resource management in the Erhai Basin. The experiment was conducted in 2022 in the agricultural area on the west side of Erhai Lake, Dali, Yunnan. Two sowing dates were set: T1 (July 12) and T2 (July 25). The soil moisture content, actual water requirements, and growth indicators of early and late sown maize at different growth stages were compared. Soil moisture content was measured using the TRIME-TDR method, and maize actual water requirement was calculated based on the Penman-Monteith formula. The early sowing treatment had higher soil moisture content at various depths compared to late sowing, with larger variations in moisture content across different soil layers in early sowing. The total actual water requirement of early sown maize (383.55 mm) was higher than that of late sown maize (334.61 mm). The precipitation during the growth period of late sown maize did not match its water requirements, affecting water supply. As the sowing date was delayed, the temperature dropped, which impacted grain filling and led to lower ear and stem weights in late sown maize. Additionally, late-sown maize was prone to earlier senescence. Late sown maize reduced physiological activity to increase leaf water use efficiency, whereas early sown maize relied on higher physiological activity to promote growth. The study found that crop growth is closely related to the adaptability to climatic conditions. Early sown maize is better adapted to the temperature changes and precipitation distribution characteristics of the Erhai Basin, leading to improved growth performance and drought resistance. These findings provide specific recommendations and guidance for agricultural water resource allocation and management in the Erhai Basin.

In order to explore the effect of deep moistube irrigation on root distribution and root water absorption of fruit trees, the buried depth and length of moistube irrigator were used as control factors. Moistube buried depth (D) was set at two levels (10 cm and 20 cm), and moistube length (L) at three levels (30、40 and 50 cm). These, along with a surface irrigation control, constituted a total of seven treatments. There were seven treatments in total. The effects of different treatments on soil moisture distribution and root distribution were investigated. A root water absorption model was also constructed to analyze treatment impacts on root water absorption. Additionally, correlations among soil moisture, root length density, and root water absorption rate were analyzed. Results showed that the soil moisture diffuses around the center of the moistube irrigator under deep moistube irrigation, forming an elliptical high-moisture zone. The soil moisture of surface irrigation decreased gradually with the increase of depth. Vertically, root length density and root water absorption rate under both deep moistube and surface irrigation initially increased and then decreased with depth. Horizontally, under deep moistube irrigation, root length density in the 20~80 cm mid-deep soil layer initially increased and then decreased with distance from the moistube, peaking at a horizontal distance of 60 cm. Specifically, in the 20~80 cm mid-deep soil layer, treatments D20L40 and D20L50 resulted in soil water content 14.13% and 14.64% higher, respectively, than surface irrigation. The area covered by high root length density under these treatments was 80.07% and 86.92% larger, respectively, than under surface irrigation. Furthermore, their root water absorption rates were 13.91% and 23.90% higher, respectively, than surface irrigation. Correlation analysis revealed a very strong relationship among soil moisture, root length density, and root water uptake rate under the D20L50 treatment, which also exhibited the highest Pearson correlation coefficients among all treatments. Soil water distribution under the D20L50 treatment best matched the fruit tree root distribution, identifying D20L50 as the optimal irrigation treatment.

To explore the effects of different biogas slurry substitution ratios for nitrogen fertilizer on root characteristics, soil pH, soil nutrients, and soil enzyme activities in greenhouse tomatoes, a study was conducted using greenhouse tomatoes as the subject. Biogas slurry N replaced fertilizer N based on N content, while the total N application rate remained constant across treatments. Seven treatments were established: pure biogas slurry (CF1), pure nitrogen fertilizer (CF2), and varying substitution ratios (T1: 75%; T2: 50%; T3: 35%; T4: 25%; T5: 15%). The study examined responses in tomato root characteristics, root activity, soil pH, soil nutrients, and soil enzyme activities. Results showed that biogas slurry as a substitute for nitrogen fertilizer achieves a more balanced nutrient release across treatments, with T3 and T4 yielding the highest root activity and development during the flowering, fruiting, and ripening stages. All biogas slurry treatments reduced soil pH. The CF1 treatment exhibited the highest total nitrogen content across the 0~60 cm soil profile, peaking at 1.949 g/kg at the 10~20 cm depth. Biogas slurry's effects on soil organic matter were most pronounced in the 0~20 cm layer, with organic matter content following the order T3 > T4 > T5 > T2 > T1. The T3 treatment achieved the best results for alkali-hydrolyzable nitrogen in the 0~30 cm layer. Soil enzyme activities (S-UE, S-NR, and S-AG) decreased with depth, with T3 achieving the highest S-UE activity and T4 the highest S-NR and S-AG activities. A substitution ratio of 25%~35% biogas slurry for nitrogen fertilizer optimally balanced nutrient release, stabilized soil pH, increased levels of organic matter, total nitrogen, and alkali-hydrolyzable nitrogen, and enhanced soil enzyme activities, supporting goals of improved quality and efficiency in greenhouse tomato production.

Exploring the establishment of inter-provincial horizontal ecological compensation mechanism for grain production and marketing areas plays an important role in balancing the interest differences between main producing and marketing areas and ensuring national food security. In this paper, the economic value of water resources in 31 provinces (Taiwan Province and Hong Kong and Macao Special Administrative Regions are not studied) in China is quantified by emergy method on the basis of calculating the virtual flow momentum of the provinces by using the minimum transportation cost method and CROPWAT model. Then, the opportunity cost of the virtual water output area is calculated, and the subject and object of compensation are defined in combination with the virtual water flow of grain. The Willingness to pay coefficient is introduced to calculate the ecological compensation standard from the perspective of inter-provincial virtual water flow of grain. The results are as follows. ① In 2021, Anhui Province, Inner Mongolia Autonomous Region, Heilongjiang Province, Jilin Province, Henan Province, Jiangxi Province, Hainan Province, Xinjiang Uygur Autonomous Region and Ningxia Hui Autonomous Region were identified as net recipients of virtual water ecological compensation, and the other 22 provinces (Taiwan Province and Hong Kong and Macao Special Administrative Regions are not studied) were net payers of ecological compensation. ② Among the major grain-producing areas, Heilongjiang Province should receive the highest net compensation of 36.829 billion yuan, while Inner Mongolia Autonomous Region deserves the lowest net compensation of 9.266 billion yuan; Among the main grain marketing areas, Guangdong Province should pay the highest net ecological compensation of 20.322 billion yuan, Tianjin should pay the least net ecological compensation of 987 million yuan. Among the regions with balanced grain production and marketing, the Tibet Autonomous Region should pay the lowest net ecological compensation of 30 million yuan. ③ The compensation standard for grain virtual water was primarily concentrated in the range of 0.2 yuan/m³ to 1.5 yuan/m³.

Agriculture is the water use sector, but the agricultural water use efficiency is relatively low. Analyzing the regional water use efficiency and its main influencing factors is helpful to propose appropriate measures to increase the efficiency. This study used the Super-Efficiency Slacks-Based Measure (SE-SBM) model and the Malmquist index to estimate the agricultural water use efficiency and its decomposition components in Yunnan Province from 2011 to 2022. Subsequently, a panel Tobit model was utilized to examine the key factors influencing agricultural water use efficiency. Results indicate that the agricultural water use efficiency in Yunnan Province showed an overall fluctuating downward trend with significant regional disparities. Technological progress was identified as the primary driver for improving agricultural water use efficiency, while the declines in pure technical efficiency and scale efficiency have hindered its further improvement. Water use structure and economic development level had significant negative effects on efficiency, while the abundance of water resources, urbanization level and level of science and technology had no significant impact on agricultural water use efficiency. To improve agricultural water use efficiency, it is recommended to strengthen the research and development as well as the promotion of water-saving technologies, optimize the agricultural planting structure, improve the allocation of water resources, and perfect the management system for agricultural water use.

Since the 20th century, the Analytic Hierarchy Process (AHP) has been widely applied in decision analysis problems such as comprehensive evaluation and risk analysis. However, the rules for assigning the importance of indicators in AHP have not been systematically organized. Furthermore, relevant literature often lacks detailed descriptions of the assignment process and consistency checks, making it difficult for readers to assess the rationality of the assignments. This paper systematically analyzes the methods and research progress in assigning indicator importance in AHP, summarizes the rules for assigning indicator importance, and elaborates on the advantages of the “addition rule” and “multiplication rule” as well as their limitations and appropriate applications. Finally, it highlights the issues present in the application of AHP within domestic water resources journal literature, and recommends that the “addition rule” should be widely applied and the “multiplication rule” should be used reasonably in the future, thereby enhancing the scientific and rational assignment of indicator importance.