Integrated Catchment Management Research Articles

Advances in Water in Agroscience

Worldwide, water is essential for maintaining an adequate agricultural production and fostering a sustainable ecosystem for humanity alongside diverse flora, fauna, and microbial life. However, the intensification of anthropogenic activities, the occurrence of climate variability, and the presence of environmental issues are still threatening the quantity and quality of fresh water. Therefore, integrated water management is critical for the sustainable development of a region. This Agrociencia Uruguay Special Issue on “Advances in Water in Agroscience” is designed to draw attention to new concepts, approaches, methodologies, and novel applications aiming to improve sustainable and integrated water resource management. This Special Issue contains fifteen publications sorted into the following macro fields: irrigation and water management, integrated catchment management, and water quality and environmental sustainability.

Comparative Analysis of Flood Prevention and Control at LID Facilities with Runoff and Flooding as Control Objectives Based on InfoWorks ICM

Climate change and urbanization have led to an increase in the amount of water flowing into traditional drainage systems, which results in frequent urban flooding. Low–Impact Development (LID) facilities, with their distributed feature, are one of the important means to mitigate flooding and have been widely used. In this paper, based on integrated catchment management (ICM), we compare the abatement of runoff, flooding, and ponding under two durations of rainfall and eight different return periods with runoff as the control objective (RACO) and flooding as the control objective (FACO) for the deployment of LID facilities. The waterlogged area of FACO is higher by a range of 92.462 m2 to 24,124.39 m2 compared to RACO. Both percentage reduction of overflow volume and runoff volume tend to decrease gradually with the increase in the return period. For the percentage reduction of runoff volume per unit area, sometimes RACO is greater than FACO, and sometimes vice versa, while for the percentage reduction of overflow volume per unit area, the range where FACO exceeds RACO is between 0.29 to 10.95 (%/ha). The cost of FACO has decreased by 4.94% to 46.20% compared to RACO. This shows that FACO’s LID deployment method can fully utilize the capacity of LID facilities to mitigate inundation, reducing the cost of LID facilities to a certain extent.

Advocating Integrated Catchment Management for Hong Kong Northern Metropolis

Rapid urbanisation and population growth have brought significant transformations in the built and natural environment in Southeast Asian cities. In this process, rivers are crucial components in alleviating the negative impacts of urban development, primarily in relationship with flood prevention, recreational space provision, and agricultural production. Previous research has provided ample knowledge about river management’s ecological and economic impacts; however, limited attention has been given to the impacts of channelisation on rural degradation and non-conforming land-use expansion. This longitudinal research employs quantitative analysis of the spatial-temporal dynamics of the landscape transformations associated with river management, using a case study in Yuen Long, Hong Kong. The results showed intensified degradation in the agricultural landscape with an intense increase in non-conforming land use following channelisation, revealing that the hydrological alterations play a pivotal role in rural degradation. Finally, this research underscored the significance of incorporating river management into urban planning at the catchment level for future rural and periurban development.

Macroinvertebrate conservation in river ecosystems: Challenges, restoration strategies, and integrated management approaches

AbstractRiver ecosystems face growing threats from human‐induced stressors, resulting in habitat degradation and biodiversity loss. Crucial to these ecosystems, macroinvertebrates maintain river health and functioning. In this review, we examine the challenges confronting macroinvertebrates, explore restoration strategies and management approaches, and shed light on knowledge gaps and future research directions. Habitat degradation, water pollution, climate change, and invasive species are discussed as key challenges. Various restoration strategies, such as in‐stream habitat restoration, flow regime restoration, riparian zone restoration, and connectivity restoration, are evaluated for macroinvertebrate conservation. Integrated catchment management, adaptive management, community‐based management, monitoring, and policy integration are highlighted as essential management approaches, and knowledge gaps in long‐term monitoring, innovative restoration techniques, climate change resilience, and policy incorporation are identified as areas calling for further research. Ultimately, a proactive, adaptable, and cooperative approach to river management will ensure macroinvertebrate conservation and sustainable river ecosystems.

Simulation and Comprehensive Evaluation of the Multidimensional Environmental Benefits of Sponge Cities

The implementation of grey and green infrastructure is an effective means to address urban flooding and nonpoint source pollution, but due to the complexity of the process and the diversity of benefits, there is a lack of measurement of the comprehensive benefits. Adopting a typical university in Beijing as an example, this paper simulated the multidimensional benefits of the water quantity, water quality, and ecology of grey and green facility renovation by coupling the storm water management model (SWMM) and InfoWorks Integrated Catchment Management (ICM). Monetization methods and economical means were employed to characterize the comprehensive benefits. The results showed that grey and green infrastructure retrofitting reduced the number of severe overflow nodes in the study area by 54.35%, the total overflow volume by 22.17%, and the nonpoint source pollution level by approximately 80% under the heavy rain scenario and 60% under the rainstorm scenario. The annual benefits of grey and green infrastructure renovation reached CNY764,691/year: of this amount, CNY275,726/year was from hydrological regulation, CNY270,895/year was from nonpoint source pollution reduction, and CNY218,070/year was from ecological improvement. The benefits of green facilities were higher than those of grey facilities, and the combined benefits were negatively correlated with the rainfall level, with a total benefit–cost ratio of 1.19. The results provide methodological and data support for grey and green infrastructure retrofitting within the context of sponge cities.

A novel framework for turbidity source apportionment of the urban lakeside river network

Turbidity source apportionment is essential but complex for precise environmental rehabilitation of worldwide urban lakeside river networks impaired by turbidity. A new turbidity source analysis framework including in-situ sampling, vessel monitoring, remote sensing, and hydrodynamic modelling was proposed, where the critical processes of flow reversal from the turbid lake, navigation, and urban non-point source in urban lakeside river networks were explicitly considered. The case study results showed that the turbidity problem (mean value was 211.3 nephelometricturbidityunits (NTU)) was primarily led by suspended inorganic matter (58%), followed by suspended organic matter (19%) and other matter. The Tiaoxi River and busy shipping contributed most to the annual total suspended solids load of the target river, with the same percentage of 34%. The turbid Lake Taihu provided 64,663 tonnes and 31% of the total suspended solids load, focusing on the autumn and winter months. Tiaoxi River load was highly concentrated on the storm events, which accounted for 71.4% of the annual Tiaoxi River source (209846 tonnes). The large water volume of reverse flow and the high TSS concentration of Lake Taihu in the autumn and winter months accounted for the seasonal change in Lake Taihu’s TSS load. The coronavirus disease lockdown reduced the mean monthly total suspended solids concentration of 152.4 mg/L in November and December 2019 to 49.2 mg/L in January and February 2020, by limiting the waterway transportation and the market demand for building materials. The river estuary’s vegetation interception belt, shipping restriction and rerouting, and integrated catchment management were advised to mitigate the urban river network turbidity.

Long-Term Change of Lake Water Storage and Its Response to Climate Change for Typical Lakes in Arid Xinjiang, China

Lakes play a role as the sentinel of climate change. Surrounded by vast expanses of barren land with limited infrastructure, there is also a lack of knowledge about the dynamics of dryland lakes. The change of lake area can be effectively monitored by remote sensing, and multi-source satellite altimetry datasets provide the possibility to obtain long-term lake water level data. Using the Global Surface Water Monthly Historical dataset and altimetry water level dataset (Hydroweb), we reconstructed a time series of lake water storage changes in Xinjiang, Northwestern China, by establishing the empirical models based on the statistical relationship between the surface area and water level of each lake. We further explored lake response to climate change. The results show that the storage of water at Ayakkum Lake, Aqqikkol Lake and Aksayquin Lake have been undergoing an obvious expanding trend from 2000 to 2020, at a rate of 3.59×108m3/a, 9.43×108m3/a and 0.44×108m3/a, respectively. In the plain and transition zone, Ulungur Lake showed an upward tendency (0.413×108m3/a) in water storage, while Manas Lake and Bosten Lake experienced shrinkage with descending rates of −0.1×108m3/a and −0.86×108m3/a. Temperature changes significantly affect the lake water storage on plateaus, especially those lakes supplied with a large proportion of glacial meltwater. Precipitation is a key factor for changes of lake storage in the plain and transition zones. Meanwhile, extreme weather and man-made factors also play crucial roles. To reduce the risk of flood and drought disasters, rational regulation of water resources is required, and a large-scale integrated catchment management plan can avoid inadvertent trade-offs. This research provides a new perspective for lake water storage inversion, as well as data support for water resources management in arid areas including Xinjiang.

Economic loss of urban waterlogging based on an integrated drainage model and network environ analyses

In this study, an economic loss assessment framework was proposed to evaluate the economic losses of urban waterlogging based on the integrated catchment management (ICM) model and information-based network environ analysis (NEA). First, the urban waterlogging model was constructed based on the ICM model to simulate the submerged depth, inundated area and duration of waterlogging. Second, the initial waterlogging risk of different economic sectors was combined with the submerged depth-disaster loss rate curve. Last, the information-based NEA was employed to quantify the distributed control relationships among different economic sectors. The results of a case study of Beijing showed that direct economic loss can reach 16.3 billion yuan in a recurrence period of once in 50 years. Forty percent of the waterlogging risk was transferred to the downstream regions or sectors via the national supply chain. The proposed economic loss assessment framework may help promote waterlogging prevention strategies.

Mitigating floods and attenuating surface runoff with temporary storage areas in headwaters

AbstractTemporary storage areas (TSAs) represent a category of soft‐engineered nature‐based solutions that can provide dispersed, small‐scale storage throughout a catchment. TSAs store and attenuate surface runoff, providing new additional storage during flood events. The need for such additional catchment storage will become more urgent as the frequency and magnitude of extreme hydrological events increases due to climate change. Implementation of TSAs in headwater catchments is slowly gaining momentum, but practitioners still require further evidence on how such measures function during flood events. This review focuses on the role of relatively small‐scale (<10,000 m3) TSAs in headwater catchments for flood risk management. It also explores the potential wider benefits for implementing these as part of an integrated catchment management approach. TSA flood mitigation effectiveness is primarily determined by the TSA's available storage prior to the event. At the local scale, this can be represented by the relationship between TSA inputs, outputs and total storage. Factors influencing the local functioning and effectiveness of TSAs are discussed, with potential considerations for optimizing future TSA design and management. Hydrological models have suggested that TSAs could be used to effectively attenuate high magnitude events. However, future considerations should involve addressing the lack of empirical evidence showing TSA catchment scale effectiveness and how local TSA functioning might change in time. Small‐scale headwater TSAs offer a holistic and sustainable approach to catchment management that can deliver both local benefits to landowners and wider flood risk mitigation for society.This article is categorized under: Engineering Water > Sustainable Engineering of Water Science of Water > Water Extremes Science of Water > Hydrological Processes

Anthropogenic Land Use and Land Cover Change as Potential Drivers of Sediment Sources in the Upper Crocodile River, North West Province, South Africa.

In this study, we investigated the accelerating pace of anthropogenic land use and land cover change (LULCC) disturbance, which has generated enormous impacts on the Crocodile River. Spot images from 1996, 2009 and 2022 were used to generate the land use maps and quantify the changes. A supervised classification with the maximum likelihood classifier was used to classify the images. Sediment sources were classified into two sources, revealed by erosional characteristics in the catchment. A gamma spectrometry detector, high-purity germanium (HPGe) “Well” detector by Canberra and inductively coupled plasma mass spectrometry (ICP–MS) were used for the analysis of the samples. The results revealed that from 1996–2022, built-up areas, bare land and water bodies increased by 3.48%, 2.47% and 1.90%, respectively. All the LULCC classes increased annually from 1996–2022, except for grassland, which shrunk. The results of the radionuclides analysis showed that 210Pbex was found to be a more effective tracer than 137Cs. The mass balance model revealed that subsurface sources contributed 60%, while surface sources contributed 40%, of the sediment load in the river. This research provides valuable information necessary for integrated catchment management policies for future LULCC and soil erosion to be adopted.

Stakeholder perspectives of Integrated Catchment Management concept: A Case Study of Chiredzi sub catchment

Stakeholder perspectives of Integrated Catchment Management concept: A Case Study of Chiredzi sub catchment

Identification of floodwater source areas in Nepal using SCIMAP‐Flood

Identification of floodwater source areas in Nepal using SCIMAP‐Flood

Factors influencing participation in Integrated Catchment Management programmes in Lesotho: The case of Lekhobanyane catchment

Factors influencing participation in Integrated Catchment Management programmes in Lesotho: The case of Lekhobanyane catchment

Operational Use of EO Data for National Land Cover Official Statistics in Lesotho

The Food and Agriculture Organization of the United Nations (FAO) is building a land cover monitoring system in Lesotho in support of ReNOKA (‘we are a river’), the national program for integrated catchment management led by the Government of Lesotho. The aim of the system is to deliver land cover products at a national level on an annual basis that can be used for global reporting of official land cover statistics and to inform appropriate land restoration policies. This paper presents an innovative methodology that has allowed the production of five standardized annual land cover maps (2017–2021) using only a single in situ dataset gathered in the field for the reference year, 2021. A total of 10 land cover classes are represented in the maps, including specific features, such as gullies, which are under close monitoring. The mapping approach developed includes the following: (i) the automatic generation of training and validation datasets for each reporting year from a single in situ dataset; (ii) the use of a Random Forest Classifier combined with postprocessing and harmonization steps to produce the five standardized annual land cover maps; (iii) the construction of confusion matrixes to assess the classification accuracy of the estimates and their stability over time to ensure estimates’ consistency. Results show that the error-adjusted overall accuracy of the five maps ranges from 87% (2021) to 83% (2017). The aim of this work is to demonstrate a suitable solution for operational land cover mapping that can cope with the scarcity of in situ data, which is a common challenge in almost every developing country.

Exploring adaptive capacity to phosphorus challenges through two United Kingdom river catchments

Phosphorus (P) is a critical natural resource for food production, but one that is subject to global supply vulnerabilities. P is also responsible for endemic eutrophication in waterbodies due to poor stewardship in the food chain. Catchments are natural social-ecologically bounded systems for P use in agriculture and water management. Stakeholders, such as farmers, water and sewerage service companies, local authorities, and environmental organisations mediate catchment adaptive capacity to P supply risks and P pollution in waterbodies. Adaptive capacity at this level has been insufficiently explored in addressing the P challenge, yet is essential to it. We address this gap by exploring through a qualitative study of stakeholders in two United Kingdom catchments. Our results suggest that the awareness and relevance of P-supply challenges is low in catchments, but the problem of waterbody vulnerability to excess P is of greater concern. Our findings highlight the roles in adaptive capacity of entrenched practices; knowledge and training activities and organisations; stakeholder cooperation and synergy; funding, infrastructure, and technology; the governance environment; and time needed to draw down P. We find that farmers and water companies are especially important to adaptive capacity as they directly interact with P flows. We therefore suggest that catchment adaptive capacity would be significantly improved through a well-supported, and expanded package of existing efforts such as providing scientific evidence of catchment P dynamics; training; payments; more empowered local governance. This effort would support catchment stakeholders to adopt effective P-stewardship practices within a multi-decade integrated catchment management strategy.

The Role of Volunteers and Citizen Scientists in Addressing Declining Water Quality in Irish River Catchments

Integrated Catchment Management (ICM) frames water management in Ireland to account for the complex hydrological, biophysical, and environmental interactions along with the political, socio-economic and cultural influences inherent in the management of river catchments. Despite a range of European Union (EU) Directives, national laws, policies, and incentives, the quality of water and biological diversity in Irish rivers is declining. In response, there has been an increased effort to involve local communities in ICM through a bottom-up, nature-based citizen science approach to activate local cooperation and environmental stewardship. This paper assembles 157 examples of citizen science water-based projects (48 in Ireland as of 2021) to appraise the position of community-led water monitoring in ICM. Notable differences found between the Irish and international programmes found a greater emphasis on habitat internationally, while a taxonomy focus was evident in Ireland despite a lower number of skilled volunteer activity-based citizen science projects. The continuing decline in water quality in Ireland, even with appropriate regulations, commendable governance changes, and expansion of citizen science, suggests more work is necessary before there will be successful ICM and improvements to river water quality.

Determining the drivers and rates of soil erosion on the Loess Plateau since 1901

Attributing soil erosion to land management and climatic drivers is important for global policy development to protect soils. The Chinese Loess Plateau is one of the most eroded areas in the world. However, there has been limited assessment of historic spatial changes in erosion rates on the Loess Plateau and the major contributors driving these spatial changes. In this study, the Revised Universal Soil Loss Equation was empirically validated and employed to assess spatially distributed historical erosion rates on the Loess Plateau from 1901 to 2016. A double mass curve attribution technique was then used to investigate the impact of land management and climatic drivers on the Loess Plateau. Decadal average erosion rates and the total area with intensive erosion (>5000 t km−2 yr−1) experienced a sharp increase from the 1930s to 1970s, followed by a decline to an historic low between the 1980s and 2000s. Mean erosion rates for the 2000s were 54.3% less than those of the 1970s. However, a recent increase in erosion rates was observed between 2010 and 2016. Land management change was the dominant driver of historical erosion rate changes before 2010. Extensive deforestation and farming, driven by population increase, were responsible for intensifying erosion between the 1930s and 1970s, while policy-driven conservation schemes and revegetation led to reduction thereafter. However, the recent increase in erosion between 2010 and 2016 was mainly driven by extreme rainfall events, a major concern given climate change projections. Advanced erosion control strategies are therefore required as part of integrated catchment management that both maintain water supplies for human use during dry periods while reducing erosion during storm events.

Using WaTEM/SEDEM to Configure Catchment Soil Conservation Measures for the Black Soil Region, Northeastern China

In recent years, to combat soil erosion, large-scale soil conservation measures have been implemented in the world. Evaluation of the integrated catchment management is urgently required. In the present study, soil erosion and sediment yield under 24 scenarios were predicted, based on the water and tillage erosion model and sediment delivery deposition model (WaTEM/SEDEM). The current catchment management was not ideal, with a catchment soil loss rate (SLR) of 599.88 t km−2 yr−1 and a sediment yield of 240.00 t km−2 yr−1. The catchment management with contour tillage on <3° slopes, hedgerow planting on 3–5° slopes, terracing on 5–8° slopes, and forestation on >8° slopes with trenches along the forest and dams in gullies was the best catchment management to control soil loss, with catchment SLR that was less than the tolerable value of 200 t km−2 yr−1. However, the SLR on the <3° slopes was still higher than the tolerable value. It is not enough to control soil loss by only implementing contour tillage measure on <3° slopes, and other measures should be further implemented on these slopes. In gullies, more measures should be implemented to prevent sediment flowing out of the catchments, in Northeastern China.

Combining sediment fingerprinting and hydro-sedimentary monitoring to assess suspended sediment provenance in a mid-mountainous Mediterranean catchment

Soil erosion and sediment transport are controlled by complex factors promoting variable responses in catchment's erosion rates and sediment yields. To mitigate eventual negative effects derived from altered fluxes, integrated catchment management plans should assess the sediment cascade from upstream erosive processes, sediment mobilization through hillslopes and within the channel, up to downstream sediment yields. This study links hydro-sedimentary dynamics with sediment fingerprinting source ascription in a mid-mountainous Mediterranean catchment during five hydrological years (2013–2018). Soil colour parameters and fallout radionuclides were used as tracers to predict dominant suspended sediment sources using (i) a Bayesian mixing model (MixSIAR) and (ii) an End Member Mixing Analysis (EMMA). MixSIAR suggested that crops were the dominant source in most of the collected samples. EMMA showed similar results, clustering all except one sediment samples close to the crop and channel bank signatures. In addition, a quantitative hysteresis index was calculated and floods were clustered in function of their hydro-sedimentary characteristics. Despite different patterns were associated to each of the four identified clusters (e.g. different sediment loads and maximum suspended sediment concentrations), correlation between sediment origin and hydro-sedimentary variables was not significant due to the little seasonal variation in source type ascription.

From Kontrollverlust to Kontrollgewinn: Rediscovering a Meso-Level Normative Hierarchy for Integrated Water Management in England Using On-Line Activities

This paper presents a unique study into how to identify a meso-level normative (i.e., institutional) hierarchy of procedures that aim to deliver the ecological status of waterbodies in the UK. Using traditional survey and workshop methods, the majority of recent studies concentrate on engagement practices between macro- (government bodies) and micro- (local residents) level structures, which can be potentially replicated elsewhere. Meso-level elements (middle-level structures of control) are often regarded as ‘subjective institutional change’, e.g., failures to implement programs locally or misinterpretations of reflexive dialogs with communities. Nevertheless, it is often only meso-level structures that are capable of promoting and replicating policies elsewhere. At the same time, there is increasing appeal by governmental departments for communities to ‘self-organize’ and take responsibility for prioritizing environmental tasks, which themselves might be instigated by local trusts and voluntary organizations, the existence of which remains largely unaccounted for by central offices. The recent proliferation of Twitter accounts, with the prominent themes of water, ecology and ecosystems, which include people, organizations, businesses and ‘bots’ of various types, presents new opportunities for digital methods to gain insights into structures and functions of these virtual communities. We hypothesize that our methods can produce invaluable insights into the ‘crafting’ of environmental institutions through approaches commonly ignored by traditional ‘analog’ meso-level mechanisms. We use the example of Integrated Catchment Management in the UK, and specifically the Tamar Catchment in southwest England, in order to demonstrate how well Twitter can capture this transitory meso-level environmental political system.