Integrated ecological assessment methods as a basis for sustainable catchment management

N fluxes in an agricultural catchment under monsoon climate: A budget approach at different scales

The European Water Framework Directive prescribes that the development of a river assessment system should be based on an ecological typology taking the biological reference conditions of each river type as a starting point. Aside from this assessment, water managers responsible for river restoration actions also need to know the steering environmental factors to meet these reference conditions for biological communities in each ecological river type. As such, an ecological typology based on biological communities is a necessity for efficient river management. In this study, different clustering techniques including the Sorensen similarity ratio, ordination analysis and self-organizing maps were applied to come to an ecological classification of a river. For this purpose, a series of sites within the Zwalm river basin (Flanders, Belgium) were monitored. These river sites were then characterized in terms of biotic (macroinvertebrates), physical–chemical and habitat variables. The cluster analysis resulted in a series of characteristic biotic communities that are found under certain environmental conditions, natural as well as human-influenced. The use of multiple clustering techniques can be of advantage to draw more straightforward and robust conclusions with regard to the ecological classification of river sites. The application of the clustering techniques on the Zwalm river basin, allowed for distinguishing five mutually isolated clusters, characterized by their natural typology and their pollution status. On the basis of this study, one may conclude that river management could benefit from the use of clustering methods for the interpretation of large quantities of data. Furthermore, the clustering results might enable the development of a cenotypology useful for efficiently steering river restoration and enabling river managers to meet a good ecological status in most of the rivers as set by the European Water Framework Directive.

Land use change and hydrological response in the Camel catchment, Cornwall

Hierarchical systems integration for coordinated urban-rural water quality management at a catchment scale

Land use change and hydrological response in the Camel catchment, Cornwall

ABSTRACTThis paper provides data on the changing character of river restoration within one country within a single policy and legislative framework. The information gathered was based on web searches, meetings and questionnaire responses with organizations and individuals working as environmental policy developers, stakeholders and practitioners of catchment management and river restoration. The paper utilizes this information to explore generic issues promoting and constraining a move to integrated catchment scale river restoration. Catchment scale river restoration was defined as ‘any river restoration activity that singly, or in combination, restores natural catchment processes and a naturally functioning ecosystem and brings benefit or environmental services to the whole catchment and not just to the site of restoration’.The river restoration project data compiled showed that the number of projects in Scotland is on a strong upward trajectory, but the number of catchment scale projects is still limited. The data also showed a trend towards a range of underpinning reasons for river restoration. Traditionally the reasons for river restoration in Scotland have been strongly fisheries focussed, with another key driver being biodiversity conservation. Sustainable flood management and climate change adaptation are seen as emerging drivers of river restoration. In terms of the individuals interviewed, most appreciated that river restoration can bring about multiple benefits and should be underpinned by a good understanding of catchment processes.Our overall assertion based on our study is that unless there is a fundamental paradigm shift, a change in the nature and level of funding for river restoration and a single organization is given overall authority to direct river restoration. ‘business as usual’ will continue and the benefits of catchment scale river restoration will be limited. Copyright © 2010 John Wiley & Sons, Ltd.

Integration for sustainable catchment management

Research in the combination of hydrological variation and ecological demands plays an important role in water availability assessment and sustainable management in watershed scale. An integrative frame, consisting of hydrological regime modeling, ecological water demands estimation and recoverable resources management, is presented in this paper in order to support the implementation of the sustainable water resources management. The proposed integrative frame has been used to the research of the integrated water resources management in southern Hanjiang watershed, the water source of South-to-North Water Transportation Project in China. The amounts of ecological water demands under current situation and climate changes, is also estimated in order to evaluate the available water resources for the local users and the transportation project. Thereby, a scheme by coupling multi-water resources, namely the available water resources, the recovering rate of water resources in natural water cycle, the local water use rate and the amounts of the water transported to North, was proposed, in which the Scheafer model is applied to analyze their evolution. Eventually, the sustainable water resources management measures were assembled by the comprehensive evaluation of the schemes. The results indicate the proposed methodology provides a new way for the integrative water resources management in watershed.

Domestic agricultural and forest management suffers disturbances arising from rapid economic, social and environmental changes including climate change. Sustainable management has emerged as a key to overcoming these challenges. From the domestic and international viewpoint, we have identified mainly three (i.e. indicator, accounting, and ecological) approaches to sustainable management of agricultural and forest ecosystems. Compared to persistent investment in indicator and accounting approaches, we find the paucity of the domestic efforts in ecological approach. The latter approach can be facilitated based on the long-term meteorological and flux data including the ecosystem-level energy, matter and information flows, which have been monitored and managed by Korea Meteorological Administration, Rural Development Administration and Korea Forest Service. In order to keep up with vigorous international efforts toward sustainable ecosystem management, more interdisciplinary, multidisciplinary and transdisciplinary collaborations among diverse domestic sectors and institutes are essential.

This article demonstrates a key role that geoscience and geoscientists could be playing in promoting sustainable catchment and resource management. A new geoscience-based approach supported by a landscape-genesis (LG) model was employed to provide an alternative approach for integrated catchment management and sustainable resource use and development. The Ben Chifley Catchment case study is used to explain the application of the approach and the landscape-genesis model. The study confirmed that lithological composition, tectonic and diagenetic processes, and landform were critical factors in determining the intrinsic properties and variation in soil type, land use, land capability, steepness of terrain, erosion, and resource degradation within the catchment. The landscape-genesis model, which is based on the geological and geomorphic genesis of the landscape, proved to be a powerful tool to predict the inherent carrying capacity and resilience of the various biophysical systems in the catchment. Although this approach is still in its infancy, its application has demonstrated that it has a strong potential in terms of undertaking sound integrated assessment, predicting potential resource degradation under different land uses, and developing sound management practices and solutions to advance the goal of ecological sustainability.

Evaluating the potential of qualitative reasoning models to contribute to sustainable catchment management

Розглянуто поняття сукцесії та генези лісостанів. Викладено питання лісової типології з позицій забезпечення стабільності природного відбору в популяціях деревних видів та відповідного ведення лісового господарства. Проаналізовано особливості популяційного підходу до екозбалансованого лісогосподарювання. Підхід базується на тотожності сукцесійного і популяційного процесів лісостанів у просторі й часі. Розглянуто питання сукцесійних змін лісостанів для грабово-букових та дубово-букових типів лісу Закарпаття. Рекомендуючи лісовідновлення з використанням природного поновлення, формування насаджень розглянуто з лісокультурних позицій, для яких придатнішою є еколого-лісівнича типологія. Генезисний ряд об'єднано за типами лісорослинних умов для ведення певного типу лісового господарювання (гірське лісівництво, екологічно орієнтоване чи лісоексплуатаційне), які передусім враховують лісоексплуатаційний аспект та відповідне лісовідновлення. Популяційний підхід на типологічній основі дасть змогу прив'язати ці загальні положення до певних гірських територіальних комплексів. Для вирішення питання щодо поєднання результатів біологічних та екологічних досліджень в лісознавчу парадигму на типологічних засадах запропоновано сукцесію, як стадійний процес, розглядати в контексті розвитку типу лісу, його генези відповідної класифікації за стадіями.

The changes to catchment scale flood risk following river restoration works, including the addition of large wood logjams to the channel, are poorly quantified in the literature. Key concerns following river restoration for river managers and other stakeholders are changes to flood hydrology at the reach and catchment scale and changes in the mobility of large wood pieces. The effects of accumulations of large wood (logjams) on local flood hydrology have been documented in the literature, showing logjams slow flood wave travel time and increase the duration and extent of local overbank inundation. Modelling studies conducted at a reach scale have shown that these local effects can slow flood wave travel time through a reach and delay the timing of flood peak discharge at the reach outflow. How these local and reach scale effects translate to the catchment scale remains to be illustrated in the literature. In this thesis a combination of field and modelling studies are used to; elucidate the link between logjam form and function, to quantify the mobility of pieces of large wood relative to their physical characteristics, to predict the changes in floodplain forest restoration over time and to provide predictions of changes to catchment scale flood hydrology following river restoration at a range of scales and locations. It is shown that logjams inducing a step in the water profile are most effective at creating diverse geomorphology and habitats. Logjams were found to account for 65% of flow resistance in forested river channels, rising to 75-98% of flow resistance where the logjam was inducing a step in the water profile. Large wood in small forested river channels was found to be highly mobile with 75% of pieces moving, with the longest transport length of 5.6km. Large wood mobility is governed primarily by the length of a piece of wood with wood in excess of 1.5x channel width a threshold for a lower probability of movement. Hydrological modelling using OVERFLOW shows that reach scale river restoration can lead to modest changes in catchment scale flood hydrology. It is concluded that flood risk management can incorporate river restoration, but that results are likely to be unpredictable if engineered logjams are used alone. Substantial benefits in reducing catchment outflow peak discharge (up to 5% reduction) are modelled for floodplain forest restoration at the sub-catchment scale (10-15% of catchment area), rising to up to 10% reductions as the forest matures and becomes more complex.

Erosion-induced soil organic carbon (SOC) loss substantially affects the redistribution of global organic carbon. The Chinese Loess Plateau, the most severely eroded region on Earth, has experienced notable soil erosion mitigation over the last few decades, making it a hotspot for soil erosion studies. However, the overall rate of SOC loss and spatiotemporal evolution under changing environments remain unclear. In this study, we investigated SOC loss from 1982 to 2015 in the severely eroded Hetong region of the Chinese Loess Plateau by combining the Revised Universal Soil Loss Equation (RUSLE) model and the localized enrichment ratio function derived from field observations and attributed the changes in SOC loss to climate- and human-induced vegetation changes. The results showed that SOC loss in the Hetong region was 64.73 t·km−2·yr−1, 16.79 times higher than the global average. Over the past 34 years, SOC loss decreased by 23.84%, with a total reduction of more than 105.64 Tg C since the change-point year. Moreover, our study found that vegetation changes dominated the changes in SOC loss in the Hetong region, contributing 89.67% of the total reduction in SOC loss in the Hetong region. This study can inform carbon accounting and sustainable catchment management in regions that have experienced large-scale ecological restoration.

Sustainable catchment management: a role for volcanic eruptions?