River Management Research Articles

Acoustic Streaming and Heat Transfer in a Rectangular Channel with Differently Heated Horizontal Walls

Acoustic Streaming and Heat Transfer in a Rectangular Channel with Differently Heated Horizontal Walls

Quantification of large-spatial scale and in-stream factors affecting the structure of benthic macroinvertebrate communities in mountain streams

Habitat diversity plays a crucial role in shaping the structure and distribution of benthic macroinvertebrate communities. However, few studies have investigated the concurrent effects of such drivers operating at different spatial scales in mountain streams. Here, we assessed which environmental factors at different spatial scales, related to stream/river type and substrate, influence the diversity of benthic macroinvertebrate assemblages in mountain streams and rivers. Within the framework of the aquatic investigations of the Biodiversity Monitoring South Tyrol (BMS) – a newly-established, regional-based, long-term biodiversity monitoring program – benthic macroinvertebrates and a set of environmental factors describing water quality, stream/river hydromorphology and in-stream habitat characteristics were collected and analysed. The variation in total density, taxonomic richness, Shannon evenness and % Ephemeroptera–Plecoptera–Trichoptera taxa of stream benthic macroinvertebrates was assessed at multi-scale habitat levels, in 48 sampling sites across the mountainous region of the Autonomous Province of Bolzano/Bozen (Italy). The effects of stream/river type, substrates and different environmental factors on community composition of benthic macroinvertebrates were quantified, using a stepfoward Redundancy Analysis (RDA) and generalized additive models (GAMs). In addition, we performed an Indicator Value analysis to detect taxa that were significantly associated with a specific substrate and/or stream/river type. Overall, we observed significant differences in benthic biological metrics among both stream/river and substrate types. We also found at least one indicator taxa for each stream/river type, with environmental factors acting at reach and large-spatial scale – temperature, stream channel stability, elevation – being the key drivers in shaping macroinvertebrate distribution patterns in the analysed mountain rivers. While significant differences in macroinvertebrate community structures were found among substrates, the influence of stream/river type conditions was particularly evident. Apart from ranking environmental variables worth including in a long-term aquatic biodiversity monitoring program in mountain areas, our study provides a baseline for practical applications. For instance, depending on the desired outcome of habitat heterogeneity restoration, it can suggest the optimal scale (landscape vs. reach vs. patch) for prioritizing in-field interventions.

Impacts of Flash Flood on Ground Water Quality: Case Study of Central River Region, The Gambia

Floods rank as one of the most common natural calamities, impacting the lives of millions across the globe. With ongoing population growth and expanding water and land usage, the potential for contamination and human disturbances to negatively impact water bodies continues to rise globally. This paper aims to comprehensively analyze the repercussions of floods on the groundwater quality of a region called CRR in the Gambia, during the July 2022 flood event. The focus lies on exploring the change in water quality parameters of twelve water samples from wells and boreholes through laboratory analysis of eight parameters such as pH, turbidity, temperature, electrical conductivity, total dissolved solids, nitrate, iron, sulfate, and microbial proliferation. The laboratory analysis results of the physiochemical parameters such as turbidity, and iron exceeded the safe drinking water standards set by the World Health Organization (WHO) in about 60% of the sites and fecal coliform presence in 75 % of the samples. The other parameters varied differently across all sites. However, most of the values are observed to be more prominent at the open well than borehole. The Water Quality Index (WAWQI) score also shows that 1 site has excellent water quality, 25%, has good quality and 25% has fair quality. The rest of the sites which make up 42% of the samples, are all of poor quality and unsuitable for drinking purposes. The results provide a crucial groundwork for subsequent studies targeting the water quality in this area.

GIS-Based assessment of geological hazard susceptibility in Southeastern Tibetan region: An information entropy approach

The terrain and geological conditions in southeastern Tibetan region are complex, especially under the influence of hydraulic and hydroelectric development, and susceptibility to geological hazards has increased. This study focused on three counties in Changdu City. We aimed to assess the susceptibility to geological hazards in this region using Geographic Information System (GIS) technology and information entropy models. Historical geological hazard data from the local area, remote sensing data, and GIS were utilized to develop an information entropy model for landslide geological hazard analysis. Key triggering factors for landslide geological hazards in the southeastern Tibetan region were identified, and a comprehensive dataset was compiled. Information entropy model was applied to consider various influencing factors and calculate their impact on geological hazards, Landslide risk in the area was analyzed and generate a susceptibility map for geological hazards. Our results indicate significant correlations between factors, such as steep terrain, human engineering activities, and land types with landslide occurrences. The established evaluation model can reasonably predict potential geological hazard risk in Nujiang River region and partially reflect the distribution characteristics of geological hazards in the southeastern Tibetan region. This offers a scientific foundation for relevant authorities to formulate disaster prevention and response strategies.

Pemetaaan Partisipatif Potensi Wisata Bantaran Sungai Sebagai Upaya Perencanaan Pembangunan Desa

The current management paradigm of the river area is no longer seen as a protected area without any exploitation activity in it. The involvement of the community around the river in the management is an effective alternative inining the sustainable functioning of the riverside area. One of the early approaches to achieving sustainable management of river transportation is by conducting participatory mapping for administrative boundaries and development of tourism activities. The objectives of this activity: 1) provide education on the functioning of the river transport area, potential threats and strategies for sustainable river management; 2) accompany the preparation of participatory maps of the administrative ducks and the development plan of tourist activities in the village of Peniti Besar. Dedication to the community is carried out by the method of community development. The stages are surveys, potential identification, base map making, participatory mapping, map finalisation, and evaluation. Through participatory mapping, the sustainable management of river basin areas based on tourist activities, has provided extensive space for the apparatus of the village, as well as the community in developing its territory independently and intelligently, as listed in the indicator of achievement of the Sustainable Development Goals (SDGs).

Impact of Fine Sediment on Benthic Macroinvertebrates Communities of Freshwater Ecosystem: A Review

The freshwater environment in Ethiopia is exposed to severe human influence because of fast population growth and other factors. Anthropogenic activities in developing countries such as river regulation and pollution have a potentially negative cumulative impact on water quantity and quality of the rivers and wetlands, hence negatively impacting benthic invertebrates and fishes. This review aims to identify the impacts of fine sediment on the community of benthic macroinvertebrates, and freshwater food webs, and to assess the response of benthic invertebrates to fine sediment pollution. Literature review was used as a methodology. Fine segment load on the freshwater ecosystem from both point and nonpoint sources may directly/indirectly alter the macroinvertebrate communities. Organic and inorganic contaminants as well as other sediment variables (sediment grain size, total organic carbon, nutrients, etc.) were affecting the community composition of benthic invertebrates. However, habitat features like the number of supplements or the silt grain measure clarify the variation in macroinvertebrate indices and metrics. The impact of metals and, to a lesser extent, organic contaminants may also be significant. Benthic macroinvertebrates are commonly used indicators of river ecological conditions that can be adversely affected by fine sediment loads. Sedimentation can change the suitability of the substrate for some taxa, increase macroinvertebrate drift, and affect respiration and feeding. To conclude, excessive fine sediment severely alters the structure and function of macroinvertebrates. At the regional and national levels, different governmental and non-governmental organizations, research institutions, and policy makers are recommended to take responsibility for reducing sediment discharge to the freshwater ecosystem by applying different conservation measures of benthic macroinvertebrates.

The Earliest Shamanic Attributes from the Northern Angara River Region

The Earliest Shamanic Attributes from the Northern Angara River Region

Appropriate Stubble Height Can Effectively Improve the Rice Quality of Ratoon Rice.

Ratoon rice, the cultivation of a second crop from the stubble after the main harvest, is recognized as an eco-friendly and resource-saving method for rice production. Here, a field experiment was carried out in the Yangtze River region to investigate the impact of varying stubble heights on the grain quality of ratoon rice, as well as to compare the grain quality between the main and ratoon season. This study, which focused on 12 commonly cultivated rice varieties, conducted a comprehensive analysis assessing milling characteristics, appearance, and cooking quality. The results show that ratoon rice crops exhibited a higher milled rice rate and head rice rate compared to the main rice crops. Conversely, chalky rice percentage, chalkiness degree, and amylose content were lower in ratoon rice crops. Principal component analysis grouped eight relevant quality indicators of rice quality which were concentrated into three categories, with amylose content identified as the key indicator of rice quality for distinguishing between different stubble heights. Random forest results reveal a robust and significant correlation between appearance quality index and amylose content. Subordinate function analysis indicated that a stubble height of 30 cm resulted in optimal rice quality, with Lingliangyou 211 exhibiting the highest quality and Xiangzao Xian 32 the lowest. Overall, our study suggests that ratoon rice crops generally outperform main rice crops in terms of quality, with the optimal measurement at a stubble height of 30 cm. This study holds substantial importance for selecting appropriate stubble heights for ratoon rice crops and enhancing overall rice quality.

Analysis of Intercity Transportation Network Efficiency Using Flow-Weighted Time Circuity: A Case Study of Seven Major City Clusters in China

Enhancing the efficiency of intercity transportation networks is crucial for sustainable regional transport development, significantly impacting travel behaviors and energy consumption. The transportation infrastructure within the city cluster is rapidly developing to accommodate the increasing traffic demand, necessitating substantial investments. It is imperative to investigate the effectiveness of intercity traffic within urban clusters, to evaluate the influence of transportation infrastructure enhancements on regional traffic efficiency. Circuity is a conventional metric used to assess the efficiency of transportation networks, primarily emphasizing distance, while overlooking factors such as travel time and traffic flow. In this study, the concept of circuity has been redefined in terms of travel time and has been referred to as the transportation network travel speed. Subsequently, the amalgamation of travel speed within the transportation network and traffic flow culminates in the proposition of Flow-Weighted Time Circuity (FWTC). Real-time intercity navigation data, offering accurate travel time estimations, are utilized to analyze the spatial distribution of intercity transport efficiency in the seven major city clusters of China, via both automobile and train modes of transportation. The results indicate that (1) as the travel distance extends, the speed of transportation within the network typically increases, albeit with increasing fluctuations, especially in the case of intercity train travel; (2) concerning the efficiency of intercity automobile travel, most city clusters demonstrate satisfactory performance, with the exception of the Guanzhong Plain. The Yangtze River Delta and Beijing–Tianjin–Heibei regions stand out for their superior performance. In terms of intercity train efficiency, the Yangtze River Delta, Beijing–Tianjin–Heibei, and Mid-Yangtze River regions exhibit higher levels of efficiency in intercity train transportation, while the Guanzhong Plain city cluster falls behind in this aspect. On the whole, the efficiency of intercity travel using automobiles surpasses that of train travel, indicating a pressing need for improvement in the latter.

Assessing heavy metal and physiochemical pollution load of Danro River and its management using floating bed remediation

River Danro in Garhwa (India) plays a vital role as a significant source of surface water and a crucial tributary of the North Koel River, ultimately joining the Ganga River Basin. Serving both urban-industrial and rural areas, the region faces challenges, including sand mining near Belchampa Ghat. This study aimed to assess physicochemical and heavy metals pollution at nine sampling locations, utilizing the Overall Index of Pollution (OIP), Nemerow Pollution Index (NPI), and Heavy Metal Pollution Index (HPI). OIP values indicated excellent surface water quality (0.71) in non-monsoon and slight pollution (6.28) in monsoon. NPI ranged from 0.10 to 1.74 in non-monsoon and from 0.22 (clean) to 27.15 (heavily polluted) in monsoon. HPI results suggested groundwater contamination, particularly by lead. Principal component analysis (PCA) and geospatial mapping showed similar outcomes, highlighting the influence of adjacent land use on water quality. Recognizing the significance of the Danro River in sustaining life, livelihoods, and economic growth, the study recommends implementing measures like floating bed remediation and regulatory actions for effective river management. The study acknowledges weaknesses in the current practical assessment methods for water contamination. These weaknesses make it difficult to put plans for cleaning up and controlling contamination into action. Because of this, future research on developing new in-place remediation techniques should focus on creating better ways to measure how effective the cleanup is.

CULTURAL HERITAGE AND SUSTAINABLE RIVER MANAGEMENT: INCORPORATING LOCAL WISDOM IN SUBAYANG RIVER, INDONESIA

The Lubuk Larangan is a sustainable water resource management system that consists of a water system and a river. This study aims to explore the potential of cultural heritage and indigenous knowledge in relation to sustainable river management. The study was conducted in the villages of Gema and Tanjung Belit in the Riau Province, Indonesia. The data were collected through in-depth interviews, observation, and a review of the relevant literature. The collected data were analysed using descriptive qualitative analysis, which consisted of three stages: Data reduction, data display, and conclusion drawing. The results indicate that the water system’s cultural practices have played a significant role in preserving the ecosystem, sustaining natural resources, and preserving water quality in the Subayang River. This study contributes to the growing body of literature. It provides a deeper understanding of the role of local wisdom and cultural heritage in achieving long-term ecological and social sustainability. Several factors, including geographical conditions, livelihood systems, customary law, and leadership patterns, support the ecological behaviour of a community in managing river resources.

Landscape modelling of the Yalong River catchment during the uplift of Southeast Tibet

Southeast Tibet is characterized by low-relief surfaces at high-elevation, showing very little exhumation during the India–Asia collision, as well as deeply incised rivers valleys. Understanding how these low-relief surfaces adjacent to the plateau's edge survived from regressive fluvial erosion is still an enigma, which is key to understanding the formation of the plateau. In the Three Rivers Region around the Eastern Himalayan Syntaxis, the squeezing of the Salween, Mekong and Yangtze rivers’ drainage basins in their middlestream, where numerous thrusts parallel to the river channels are observed, has been invoked as the key factor driving the river evolution. More to the east, in the Great Bends Region, no such squeezing of the drainage basins has been observed; the Yalong and Yangtze rivers flow perpendicularly across northeast-trending thrust belts, generating huge (>100 km) river course bends with steep channel slopes. These faults have significantly contributed to construct the high plateau margin, including the Yalong Thrust Belt (YTB), active during the Eocene (∼35–25 Ma) and reactivated in the Miocene (15–12 Ma). By applying state-of-the-art landscape modelling (FastScape) to the Yalong River catchment, with simplified rock uplift scenario deduced from fault activities, we show that strong monsoonal precipitation on the plateau (∼1 m/yr), even during only a short period such as the Mid–Miocene Climatic Optimum (17–14 Ma), produces wide rivers and destroys the plateau edge. In contrast, modelling the orographic effect with weak net precipitation (∼0.2 m/yr) above ∼2700 or 4000 m, preserves the plateau edge and reproduces the slope of the Yalong River, but with a width larger than in nature. To reproduce both the slope and narrowness of the Yalong gorge just upstream of the YTB, a combination of a rapid Miocene rock uplift leading to a regional surface uplift, which creates a significant orographic effect and preserves interfluve low-relief surfaces close to the plateau edge, and a water inflow in upstream, which deeply incises downstream river valleys, is necessary. Such an amount of upstream water is collected from the flat and expansive headwater, inherited from the inland endorheic zone of the plateau interior, on which the hillslope processes dominate the landscape evolution.

Earlier Spring-Summer Phenology and Higher Photosynthetic Peak Altered the Seasonal Patterns of Vegetation Productivity in Alpine Ecosystems

Carbon uptake of vegetation is controlled by phenology and photosynthetic carbon uptake capacity. However, our knowledge of the seasonal responses of vegetation productivity to phenological and physiological changes in alpine ecosystems is still weak. In this study, we quantified the spatio-temporal variations of vegetation phenology and gross primary productivity (GPP) across the source region of the Yellow River (SRYR) by analyzing MODIS-derived vegetation phenology and GPP from 2001 to 2019, and explored how vegetation phenology and maximum carbon uptake capacity (GPPmax) affected seasonal GPP over the region. Our results showed that the SRYR experienced significantly advanced trends (p < 0.05) for both start (SOS) and peak (POS) of the growing season from 2001 to 2019. Spring GPP (GPPspr) had a significantly increasing trend (p < 0.01), and the earlier SOS had obvious positive effects on GPPspr. Summer GPP (GPPsum) was significantly and negatively correlated to POS (p < 0.05). In addition, GPPmax had a significant and positive correlation with GPPsum and GPPann (p < 0.01), respectively. It was found that an earlier spring-summer phenology and higher photosynthetic peak enhanced the photosynthetic efficiency of vegetation in spring and summer and altered the seasonal patterns of vegetation productivity in the SRYR under warming and wetting climates. This study indicated that not only spring and autumn phenology but also summer phenology and maximum carbon uptake capacity should be regarded as crucial indicators regulating the carbon uptake process in alpine ecosystems. This research provides important information about how changes in phenology affect vegetation productivity in alpine ecosystems under global climate warming.

Promoting Education and Literacy through the Preservation of Yongning River Boatman Work Songs

Yongning River Boatman Work Songs are traditional folk music from the Yongning River region, performed by boatmen for practical purposes during laborious tasks. The study’s objective is to investigate the promotion of education and literacy through the preservation of the Yongning River Boatman Work Song. Three key informants, including an inheritor of intangible cultural heritage, an academic expert, and a cultural heritage preservationist, provide comprehensive insights into this multifaceted topic. Data was analyzed thematically using a mixed-methods approach, including in-depth interviews, document analysis, and observations. The findings highlight the transformative power of these songs as educational tools, bridging the past and present, fostering cultural identity, and enabling multifaceted learning. Additionally, community collaboration among local individuals, cultural centers, educational institutions, and government authorities plays a pivotal role in preserving and promoting these songs. Successful initiatives for engaging the younger generation ensure the intergenerational transmission of this cultural heritage. This research suggests that cultural preservation, education, and community involvement are intertwined elements that can enrich education and enhance literacy while safeguarding intangible cultural heritage.

Phytochemical Constituents of Sap, Root and Leaf Extracts of Calotropis Procera from Select Regions in the Gambia

Medicinal plants serve as potential cure for animal and human diseases as they contain phytochemicals for therapeutic values. Most of the modern drugs produced are isolated from herbal plants. This research reports on the phytochemical constituents of the methanolic and dichloromethane (DCM) extracts of the sap, root and leaf of Calotropis procera in three select regions in The Gambia namely the West Coast Region, North Bank Region, and Lower River Region. The sap was collected in an air-tight test tube; the root and leaf were dried at room temperature for three weeks and one month, respectively and further ground into powder. Soxhlet extraction of the sap was done using both DCM for 30 minutes at 40oC to 50oC and methanol for 3 h at 60oC to 70oC. The root and leaf were extracted using cold maceration for 72 h. The methanolic extracts showed the presence of alkaloids, quinones, saponins, flavonoids, terpenoids, steroids, and carbohydrates in the sap and leaf. Quinones were present in the DCM extract of the sap and root, but absent in the leaf. While flavonoids and terpenoids were present in the sap and leaf extracts, they were absent in the root. Alkaloids, saponins, and steroids were absent in the sap and root extracts, but found in the leaf. Tannins and phenols were absent in both the methanolic and DCM extracts. The results of each of the samples collected at the three different regions were similar in their phytochemical constituents for the extracting solvents; but varied with the different solvent. The findings of this research allude to the fact that the sap, root and leaf of C. procera are good sources of therapeutic compounds that are responsible for the use of this plant in herbal medicine in The Gambia.

Applying machine learning to assess emotional reactions to video game content streamed on Spanish Twitch channels

This research explores for the first time the application of machine learning to detect emotional responses in video game streaming channels, specifically on Twitch, the most widely used platform for broadcasting content. Analyzing sentiment in gaming contexts is difficult due to the brevity of messages, the lack of context, and the use of informal language, which is exacerbated in the gaming environment by slang, abbreviations, memes, and jargon. First, a novel Spanish corpus was created from chat messages on Spanish video game Twitch channels, manually labeled for polarity and emotions. It is noteworthy as the first Spanish corpus for analyzing social responses on Twitch. Secondly, machine learning algorithms were used to classify polarity and emotions offering promising evaluations. The methodology followed in this work consists of three main steps: (1) Extracting Twitch chat messages from Spanish streamers’ channels related to gaming events and gameplays; (2) Processing and selecting the messages to form the corpus and manually annotating polarity and emotions; and (3) Applying machine learning models to detect polarity and emotions in the created corpus. The results have shown that a Bidirectional Encoder Representation from Transformers (BERT) based model excels with 78% accuracy in polarity detection, while deep learning and Random Forest models reach around 70%. For emotion detection, the BERT model performs best with 68%, followed by deep learning with 55%. It is worth noting that emotion detection is more challenging due to the subjective interpretation of emotions in the complex communicative context of video gaming on platforms such as Twitch. The use of supervised learning techniques, together with the rigorous corpus labeling process and the subsequent corpus pre-processing methodology, has helped to mitigate these challenges, and the algorithms have performed well. The main limitations of the research involve category and video game representation balance. Finally, it is important to stress that the integration of machine learning in video games and on Twitch is innovative, by allowing the identification of viewers’ emotions on streamers’ channels. This innovation could bring benefits such as a better understanding of audience sentiment, improving content and audience retention, providing personalized recommendations and detecting toxic behavior in chats.

The Impact of Urban Land Use Changes on the Morphology of the New Calabar River Catchment, Port Harcourt Metropolis, Nigeria

The New Calabar River catchment has experienced significant alterations in land use and land cover patterns due to the fast population growth in Port Harcourt. This research investigated the influence of urban land use change on the morphological structure of the New Calabar River basin, which is experiencing rapid urbanization in Rivers State. The research utilized a combination of primary and secondary data sources, specifically satellite imagery and field measurements of the hydro-geomorphic channel's breadth and depth. The findings indicated a significant rise in urbanization, resulting in the encroachment upon various land uses, including water bodies, farmlands, dense forests, and wetlands. Moreover, correlation and regression analysis revealed a significant positive link between channel morphology, discharge, and urbanization index. Therefore, it can be argued that the urbanization index and discharge are crucial in determining the river channel's current channel form and size features. The study also demonstrated a positive correlation between discharge and channel dimensions, including width and depth. The stream channel has experienced an expansion in reaction to the modification of the natural soil caused by urbanization, leading to changes in the stream flow regime. Additionally, it has been observed that the segment of the New Calabar River that encompasses urbanized regions tends to have a comparatively more significant cross-sectional channel. Incorporating urbanization analysis and its impact on morphology has facilitated the implementation of diverse geospatial analyses and sustainable watershed management in the basin.

Impact of Meadow Degradations on the Probabilistic Distribution Patterns of Physical and Mechanical Indices of Rooted Soil in the Upper Regions of the Yellow River, China

The shear strength (particularly soil cohesion) of rooted soil is an important parameter that reflects the true erodibility of meadows, particularly in meadows experiencing different degrees of degradation, ranging from undegraded (UD) through to lightly degraded (LD) and from moderately degraded (MD) to heavily degraded (HD). The cohesion of rooted soil is controlled not only by the soil moisture content and its natural density, but also by roots (including not only their density, spatial distribution, and diameters, but also their tensile strength). This study aimed to improve the current understanding of the erosion resistance of rooted soil and elucidate the impact of meadow degradation on the physical–mechanical indices of rooted soil. Based on this discussion, a one-way analysis of variance was performed at significance levels of 0.05 and 0.01 to test the impact of degradation on the physical–mechanical indices of rooted soil across degradation. Furthermore, the probabilistic distributions of the physical–mechanical indices were described using normal, gamma, Weibull, and generalized extreme values (GEV). The Kolmogorov–Smirnov (KS) test was used to identify the optimal distribution based on p-values and the Pearson correlation coefficient was used to quantify the correlation between the cohesion of rooted soil and other indices. The one-way ANOVA indicated that the soil’s natural density and soil moisture content decreased firstly, followed by an increase, the root amount and cohesion decreased, the root content experienced an initial increasing and then decreasing trend, and the internal friction angle exhibited a stepwise increasing trend. The four distributions sufficiently described the actual distribution of data on the physical–mechanical indices of rooted soil, except for the internal friction angle in UD and MD soils and the soil moisture content in MD soil. Additionally, the KS tests showed that the optimal distribution depended on both the physical–mechanical indices themselves and the degree of degradation. The Pearson correlation analysis showed that the correlation between cohesion and the other physical–mechanical indices varied considerably depending on the degree of degradation.

Phosphorus fertiliser application and the subsequent cadmium input in three provinces along Yangtze River region of China

ABSTRACT This study has undertaken an analysis of phosphorus fertiliser use in three provinces from 2010 to 2020: Sichuan, Hubei and Jiangsu along the Yangtze River basin. It was revealed that phosphorus fertiliser application rate of Hubei experienced the most significant reduction, and the application rate of Sichuan was the lowest, but its yield of different crops hardly decreased. The yield for all food crops by Jiangsu was highest, indicating the importance of strong economic development on sustainable agriculture practice. Cd input for Hubei was highest. In Jiangsu, Xuzhou, Lianyungang, and Suqian are the three cities applying the most phosphorus fertiliser, which also happen to be the cities with lowest GDP. The findings of this research could provide useful insights into the current practice of phosphorus fertiliser application in the main rice planting regions of China and facilitate the optimal use of global sustainable intensification of agricultural systems.

Study on River Protection and Improvement Based on a Comprehensive Statistical Model in a Coastal Plain River Network

When considering the contradictions between river management and protection in a typical plain river network, it is always confirmed that the river area has usually been encroached upon due to the development of human society. Based on the analysis of multiple attributes of the river network, a statistical model has been proposed in this study in order to determine the river network protection indices such as river area ratio, storage capacity and flux. In this study, a numerical method is proposed to improve the structure and connectivity of the river network by calculating the occupation and supplement balance. According to the principle of water area dynamic balance, the river network structure and its connectivity are improved through water area adjustment in a typical coastal city. As the simulation results show, the water surface ratio equals 8.17%, the storage capacity equals 112.6 million m3 and the water flux equals to 656.06 m3/s in the selected study area. The flood drainage capacity is introduced as the priority function, other functions are also improved due to river management and protection. The harmonious and sustainable coexistence between human society and the river network is then promoted. This comprehensive statistical model proved to be a good tool for the coastal area to enhance the comprehensive attributes of the coastal plain river network and the sustainable development of the local area in the future.