Catchment-based Approach Research Articles

Navigating Water Sustainability in Mineral Mining with a Systems Thinking-Based Approach

This paper provides a comprehensive review and analysis of the sustainable management of water resources in the mining industry. It presents an overview of various sustainable development frameworks for the mining sector, emphasizing the need for a more comprehensive and integrative approach to managing water resources. The paper also highlights the critical role of water in mining operations and the increasing pressure on water resources due to mining activities. Consequently, it underscores the significance of sustainable water management practices such as stakeholder engagement, catchment-based approaches, and adequate water management strategies. The researcher combined a qualitative approach with a methodology for conducting a literature review. The majority of the articles and other sources used to compile the study's data were books and academic publications that examined relevant subjects (Water sustainability, mineral mining, system thinking-based approach). The study advocates for a shift from traditional mechanistic models and linear thinking to a more holistic systems thinking approach for addressing the complex environmental challenges associated with water resources management in mining. Furthermore, it presents system dynamics modeling as a promising tool for understanding and predicting the behavior of complex water resource systems and devising appropriate strategies for sustainable outcomes. A conceptual framework for sustainable underground mine water management is proposed through a synthesis of previous studies. The framework integrates systems thinking and sustainability principles, paving the way for socially equitable, environmentally sustainable, and economically beneficial water management strategies in the mining industry.

River science and flood risk management policy in England

We review the role of science in shaping river flood risk management policy in England, highlighting the relatively recent influence of fluvial geomorphology, river ecology, climate change and ecosystem services in evidence-based decision-making. These disciplines, together with an historical perspective, catchment-scale delivery, integrated land and water management planning, and adaptive management are crucial in managing future flood risk. A central tenet of previous land drainage policy was a professional (and public) mindset about flood ‘prevention’ solutions for river flooding. As a direct consequence, more than 8,500 km of rivers were ‘improved’ by mechanical dredging during the 1930s to 1980s; habitats were destroyed, but flooding continued. A more enlightened, long-term approach has since evolved in response to environmental imperatives and lessons learnt from several major floods during the last two ‘flood-rich’ decades. River science, local knowledge and land management incentives allow more natural processes to be restored in river catchments. The natural capital and ecosystem service benefits of river systems are now better understood and quantified, whereas the importance of sediment transport is fully recognised, with sources and sinks treated more holistically than in the past. Evaluating the outcomes of innovative runoff and river management techniques from both physical and socioeconomic perspectives will determine the success of a catchment-based approach. We highlight some of the uncertainties, nuances and assumptions associated with recent initiatives such as Natural Flood Management, Citizen Science and Flood Action Groups. Further integration between policy, strategic planning and local delivery is needed to anticipate and respond to climate and catchment land use changes. River science will play a crucial part in identifying the most effective way of improving flood management and in a way that helps to deliver the recovery of nature. It will inform adaptive management to cope with climate change.

Can eDNA metabarcoding offer a catchment-based approach for biodiversity monitoring?

In previous studies eDNA metabarcoding has been demonstrated as a viable tool for catchment-level biodiversity sampling in rivers (Deiner et al. 2016). However, questions still remain over the appropriate sampling protocol for large spatial scale sampling. River reaches are composed of multiple habitats with species composition varying from one to the next (Costa and Melo 2007). Therefore, how many spatial replicates are needed to reliably represent the river network? Is the previously used approach to sample at every river confluence (Deiner et al. 2016) sufficient or is more needed? These questions were addressed using a case study in the headwaters of the Cound Brook, a tributary to the River Severn in Shropshire, UK. Two sub-catchments of the Cound Brook were used. One sub-catchment had a sample taken at the most downstream point before the confluence. Additionally, a sample at the upstream extent of the same sub-catchment was taken to estimate any correlation between the species found at the beginning of the river reach and at the end. Another sub-catchment also had the same up- and downstream sample design. However, in between was a systemic sampling regime every 500 m. This is to test if increasing the spatial resolution gave significantly different results to the sparser sampling regime. At each sample location, a 1 L water sample was sequentially filtered through membranes of three different mesh sizes: 5µm, 0.45µm and 0.2µm. Sequential filtering was performed because DNA resides in two forms in the environment (Civade et al. 2017), within whole cells (cellular DNA) and outside of cells (extracellular). The theory is that the coarser filters predominantly collect cellular DNA and the finer filters collect predominantly extracellular DNA of increasingly smaller fragment lengths. Consequently, sequential filtering could represent DNA degradation in the environment (Fig. 1). Also, Turner et al. 2014 suggested that the larger particles could determine very recent or local organisms. Therefore, we hypothesised that the DNA collected by the coarser filters would represent local diversity and the DNA collected by the finer filters would reflect biodiversity further upstream. Initial results suggest sequential filtering through the 5µm and 0.45µm filters caught detectable levels of eDNA where the 0.2µm did not catch enough to show up through gel electrophoresis. The relevance of the initial finding suggests that if we only used a 5µm filter the data collected at 0.45µm could have been discarded. Further investigations of any differences in species compositions between filters and the relationships to other sampling locations is still to be determined. This ongoing research is intended to determine the appropriate sampling protocol for a large-scale biodiversity assessment regime combining eDNA metabarcoding and species distribution modelling.

Policies for wetlands implementation in Denmark and Sweden – historical lessons and emerging issues

Natural wetlands used to cover a significant part of the landscape, but these ecosystems have declined by >50% worldwide, and even more in Denmark and Sweden. However, since the 1980s, various policies have been implemented to restore and create wetlands. This study provides a comprehensive historical overview of policies used to stimulate the creation and restoration of wetlands in Denmark and Sweden, and also analyses what factors have facilitated participation or have been barriers for landowners. The analysis of wetlands implementation programmes in Denmark showed a change towards narrower focus on nitrogen reduction from 1998 and onwards, whereas policies in Sweden often have had a wider multifunctional purpose. In both countries, there has been a change in the compensation structure from a lump sum to annual payments, parallel to an observed increase in costs for wetlands implementation. There is still a large potential for recreating many more wetlands, and the national targets have not been reached in neither Denmark nor Sweden. Key success factors, for future wetlands implementation are sufficient compensation levels, flexible scheme designs and information-based strategies documenting relevant benefits and sustainability issues. In general, more advice and support from the state, regional and local participants, and farmers’ organisations, are required to increase the participation and achieve successful and cost-efficient wetlands implementation. A collaborative and catchment-based approach holds promise, where wetland governance can serve as a platform for collaboration between policy bodies and between farmers. Additionally, politicians and decision makers need to accept the area targets presented to them when setting policy goals for wetlands implementation, and to accept that restoring and constructing wetlands requires long implementation times before results can be demonstrated.

Collaborative water management across England – An overview of the Catchment Based Approach

The Catchment Based Approach (CaBA) was established in 2013 to drive collaborative water management across England. Globally unique in its national coverage, CaBA encompasses 106 river catchment partnerships that either incorporate or work with a range of cross-sector partner organisations including environmental organisations, Government agencies, water companies, local authorities, businesses and civil society. The partnerships work through consensus to build social capital and deliver environmental improvements. Because of the variety of stakeholders and interests represented, partnerships attract a range of funds, multiplying the core monies they receive from Government. A National Support group, several thematic working groups and a team of technical specialists help to build expertise within partnerships. Supported by data and evidence, including that derived through citizen science, the partnerships have developed catchment plans that capture priorities for action. Challenges of legitimacy, funding, integration with England’s wider water management framework, and the monitoring of outcomes remain. Future opportunities exist, including closer alignment with academia and the potential for CaBA to undertake a key role in delivering the UK Government’s 25-Year Environment Plan. Several lessons learnt from the CaBA approach may be applicable internationally.

An interdisciplinary and catchment approach to enhancing urban flood resilience: a Melbourne case.

This paper presents a novel interdisciplinary and catchment-based approach for exploring urban flood resilience. Our research identified and developed a diverse set of adaptation measures for Elwood, a suburb in Melbourne, Australia, that is vulnerable to pluvial and coastal flooding. We drew on methods from social science, urban design and environmental engineering to gain integrated insights into the opportunities for Elwood to increase its flood resilience and urban liveability. Results showed that an appropriate balance of social, infrastructural and urban design responses would be required to retreat from, accommodate and protect against flood risk. These would also deliver broader benefits such as securing water supplies through harvested stormwater and mitigating extreme heat through greener landscapes. Our interdisciplinary approach demonstrated the value of (i) engaging with the community to understand their concerns, aspirations and adaptation ideas, (ii) exploring design measures that densify and use urban forms in ways that implement adaptation measures while responding to local context, (iii) adopting modelling techniques to test the performance, robustness and economic viability of possible adaptation solutions, and (iv) innovating governance arrangements and principles needed to improve flood resilience in the Elster Creek catchment. Our research also provided valuable insight on how to operationalize interdisciplinary work in practice, highlighting the importance of sharing an impact agenda, taking a place-based approach, developing a common conceptual framework, and fostering a constructive team culture.This article is part of the theme issue ‘Urban flood resilience’.

Understanding the geomorphic consequences of enhanced overland flow in mixed agricultural systems: sediment fingerprinting demonstrates the need for integrated upstream and downstream thinking

Sediment fingerprinting approaches help improve our understanding of the on- and off-site impacts of soil erosion in the critical zone, including upstream and downstream ecosystem services and the wider implications for food, water and energy security. This study evaluates the impact of intensive agricultural land management practices on overland flow generation with attention to process controls on sediment production and delivery from both hillslope and in channel sources. This study applied a sediment fingerprinting approach in the Merriott Stream catchment in rural Somerset, UK. Major and minor element geochemistry were determined for sources under cultivated (n = 12) and grazing (n = 12) land management regimes plus channel bank erosion (n = 10) for a notably incised downstream drainage network. These were compared to both suspended sediment (n = 3) and channel bed sediment (n = 4) sampled along the stream network. Sediment sources were apportioned with the MixSIAR mixing model. The dominant contributor to suspended sediment captured in transit was cultivated land (ca. 60–90%). The dominant contributor to channel bed sediment in the lower catchment was channel bank erosion (ca. 50–75%). The former was linked to enhanced overland flow and increased erodibility of cultivated soils. The latter was linked to contemporary incision of the stream network driven by a more erosive hydrological regime (i.e. increased magnitude and frequency of runoff events) which was causing localized erosion and bank failure. These in-channel processes of incision and bank failure were exacerbated by a lack of vegetation on the banks due to winter die-back of the invasive weed Himalayan Balsam. This exposes the bank surface to direct fluvial scour under winter high flows and prevents the establishment of a perennial root structure from native plants that typically plays an important role in bank stability. This study has demonstrated the need to consider a holistic catchment-based approach to understanding and managing bank erosion and, in particular, it highlights the need for integrated upstream and downstream thinking where distal runoff processes lead to increased potential for downstream channel instability.

Revisiting deliberative policy analysis through systemic co-inquiry: some experiences from the implementation of the Water Framework Directive in England

ABSTRACTWater governance is central to the crisis of the Anthropocene as climate change, population growth and changing demands for water are predicted to exacerbate threats to food, water and energy security and river functioning. Since 2000 the major policy setting in Europe for the governance of water has been the European Water Framework Directive (WFD). Empirically grounded post-positivist water governance research strongly anchored in interpretivist and constructivist systems’ traditions akin to deliberative policy analysis (DPA) is reported. The case is made, based on the UK (England), that an opportunity to transform water governance has been lost because WFD implementation has been prescriptive, top-down and fails to engage with dynamic complexity. Some changes have emerged from the adoption of a Catchment-Based Approach (CaBA), partly triggered by threat to government of a judicial review, but governance praxis and trajectory remain contested. The paper reports on new pathways and options for change emerging from a systemic co-inquiry, a deliberative instrument, which emphasises the importance of institutionalising community action at catchment scale and re-framing the enactment of the Directive as part of an iterative social learning system for water governance. In the light of our findings, implications for future DPA scholarship are explored.

Passive sampling of polar emerging contaminants in Irish catchments.

Passive sampling (PS) is a very useful approach for the monitoring of emerging contaminants in environmental matrices, showing greater sensitivity than can be achieved by current best practice - grab sampling - and is applicable to a wide variety of compounds. An EU Directive (2013/39/EC) has added substances to the existing Water Framework Directive (WFD) Priority Substance list. Investigation into PS in the monitoring of these compounds is necessary to show the potential of this technique in supporting monitoring requirements under the WFD. A catchment-based approach evaluated the occurrence of these compounds in Irish surface waters. This work deals with the challenges associated with the use of PS in a legislative context, and for routine monitoring of emerging contaminants. Looking at a number of sites across Ireland, upstream and downstream of wastewater treatment plants, the focus was on polar analytes and polar PS (POCIS). With method limits of detection (LODs) of 0.001 mg L-1 pharmaceuticals and endocrine disrupting chemicals (EDCs) were found in water and passive samples alike, whereas the polar pesticides were not often detected or were below the annual average environmental quality standard levels. The results of this study show the potential for PS as a monitoring technique for emerging and watch-list chemicals.

Reconstructing palaeoclimate and hydrological fluctuations in the Fezzan Basin (southern Libya) since 130 ka: A catchment-based approach

We propose a novel method to evaluate regional palaeoclimate that can be used to alleviate the problems caused by the discontinuous nature of palaeoenvironmental data found in deserts. The technique involves processing satellite imagery and DEM's to map past rivers, catchments and evaluate the areas and volumes of palaeolakes. This information is used to determine the new Lake Evaluation Index (LEI) that allows a qualitative estimate of the amount of sediment received by lakes and how long-lived those lakes are. Lakes with considerable longevity and large sediment stores are selected for study. Validation is performed using image interpretation of remote sensing data, UltraGPR surveys and fieldwork. These techniques are also used to identify and study spring deposits and fluvial landforms that provide valuable palaeoclimate information. The method is applied to the Fezzan Basin in southern Libya focusing on the Wadi ash Shati and Wadi el-Agial catchments. Results indicate that the palaeohydrology is accurately mapped except within dune fields. We analysed the sedimentology of the key deposits identified by this methodology, developing a chronology using optically stimulated luminescence (OSL) and radiocarbon dating. We find evidence for relatively humid conditions during MIS 5c/d and e, as well as during the early to middle Holocene. Larger lakes and more extensive river systems were present during MIS 5 than are found during the Holocene, suggestive of greater humidity. The Holocene humid period started at ∼11 ka and continued until ∼5 ka being interrupted by abrupt periods of aridity at ∼8.2 ka and ∼6 ka that coincide with North Atlantic cooling. After each of these arid events the climate was less humid than previously, suggesting that they were superimposed upon an overall drying trend. The termination of the Holocene humid period in the Sahara has received much scrutiny in recent years, and sediments of Palaeolake Shati provide a continuous record of this. We do not find evidence to support the hypothesis of either sudden or gradual aridification of the Sahara at ∼5 ka, instead we find that that aridity started to develop at ∼6.5 ka, whereupon the lake levels oscillated until finally drying-up by 5.3 ka. Most of the other lakes in the Fezzan also dried up at ∼ 5ka. We suggest that thousands of years of aridification prior to 5 ka shrunk these lakes so that additional aridity at this time led to their final desiccation. Because lakes are prodigious dust sources this mechanism potentially explains the rapid rise in dust flux to the Atlantic at 5 ka, with this final drying being the culmination of longer term aridity, albeit overprinted with considerable climate variability.

Geoinformation mapping of soil erosion in the Middle Volga region

The results of a medium-scale geoinformation mapping of soil erosion on an area of about 150000 km2 in the Middle Volga region are analyzed using the catchment-based approach. A quantitative index of the development of soil erosion on the agricultural lands is suggested. It reflects the intensity of soil erosion on slopes within the river catchments. A computer-based vector map of the boundaries of 3331 elementary catchments has been developed. It represents the territorial units for the analysis of soil erosion. Archive materials from the former institutes for land survey have been used to compile a series of the maps of soil erosion in river catchments on a scale of 1: 200000. The zoning of erosional processes has been performed, and the natural and anthropogenic levels of soil erosion in different basins have been estimated. The analysis of these materials shows that the topography and agricultural activity of humans are the major factors controlling the development of erosion. The maximum development of soil erosion in the studied region is typical of the subzone of broadleaved forests.

Catchment-based water management in the mining industry: Challenges and solutions

The mining industry’s aspirations towards a catchment-based water management approach have similarities with the concept of Integrated Water Resources Management (IWRM) which has been committed to by many governments around the world. However IWRM has proved challenging to implement in practice. This paper considers the question: Which challenges are mining companies likely to face when implementing a catchment-based approach at a mine site level? Drawing on lessons from the IWRM literature, it is argued that three coordination challenges must be overcome: fit, horizontal interplay, and vertical interplay. The problem of fit arises because the boundaries of mining leases do not align with water catchments, necessitating collaboration between companies to manage cumulative impacts. Problems of horizontal interplay arise because mining sites are typically one of several water users within a catchment, requiring that they liaise with diverse stakeholders to understand the multiple values provided by water. Problems of vertical interplay arise across organizational levels and require alignment between corporate and site priorities. Drawing on examples from Australia, Mongolia and Germany, each coordination challenge is described, mechanisms for overcoming each challenge are discussed, and the paper concludes with future research directions.

MOGREPS-UK Convection-Permitting Ensemble Products for Surface Water Flood Forecasting: Rationale and First Results

ABSTRACT Flooding is one of the costliest hazards in the United Kingdom. A large part of the annual flood damage is caused by surface water flooding that is a direct result of intense rainfall. Traditional catchment-based approaches to flood prediction are not applicable for surface water floods. However, given sufficiently accurate forecasts of rainfall intensity, with sufficient lead time, actions can be taken to reduce their impact. These actions require reliable information about severity and areas at risk that is clear and easily interpreted. The accuracy requirements, in particular, are very challenging, as they relate to prediction of intensities that occur only infrequently and that typically affect only small areas. In this paper, forecasts of intense rainfall from a new convection-permitting ensemble prediction system are evaluated using radar observations of intense rain and surface water flooding reports. An urban flooding case that occurred in Edinburgh in 2011 is first investigated and then a broader look is taken at performance through a 3-month period during the London Olympic and Paralympic Games in 2012. Conclusions are drawn about the value of the ensemble and the particular means of presenting the forecasts, and areas requiring further work are highlighted.

Institutional adaptive capacities to promote Ecosystem-based Adaptation (EbA) to flooding in England

Purpose – The purpose of this paper is to assess the inherent adaptive capacities of multilevel flood management institutions in England that are necessary to espouse the concept of Ecosystem-based Adaptation (EbA). Design/methodology/approach – This paper is based on an extensive assessment of flood management literature including European and English flood management policies, strategies, regulations and reports. First, an assessment protocol was developed from systematic literature search and, second, multilevel flood management policies and organizations were evaluated. A qualitative scoring method was applied at the assessment stage. Findings – The protocol included 18 major assessment criteria under seven EbA principles. Application of the protocol showed that English national flood policies showed comparatively greater adaptive capacities than European- and local-level policies and local organizations. Specialized flood management policies such as Catchment Flood Management Policies at the local level and European Policies such as flood directives are among the lowest-scoring policy institutions. It was also identified that there is an emerging trend of stakeholder participation, catchment-based approach and knowledge-based adaptation planning at the national level which potentially can be the entry points of wider-scale EbA implementation. This paper recommends proactive roles of local executive organizations through improving institutional communication, consideration of catchment-scale planning with clear adaptation goals and valuing local knowledge base. Originality/value – The research is important to identify the institutional aspects of adaptive capacity that require attention for promoting alternative adaptation measures such as EbA.

A fast-response methodological approach to assessing and managing nutrient loads in eutrophic Mediterranean reservoirs

With many lakes and other inland water bodies worldwide being increasingly affected by eutrophication resulting from excess nutrient input, there is an urgent need for improved monitoring and prediction methods of nutrient load effects in such ecosystems. In this study, we adopted a catchment-based approach to identify and estimate the direct effect of external nutrient loads originating in the drainage basin on the trophic state of a Mediterranean reservoir. We also evaluated the trophic state variations related to the theoretical manipulation of nutrient inputs. The study was conducted on Lake Cedrino, a typical warm monomictic reservoir, between 2010 and 2011. We assessed the hypereutrophic condition of the reservoir by monthly samplings of the water column and compared these results with the amount of nutrient load originating from anthropic activities in the drainage basin [42.6tPy−1 for total phosphorus (P) and 531tNy−1 for total nitrogen (N)]. We verified how the predictive OECD management model could be confidently applied to predict the P concentration in the reservoir on the basis of estimated loads from the drainage basin (98.7mgPm−3 assessed versus 101mgPm−3 estimated, approximately 2.5% over). Different scenarios are presented showing how it is possible to reduce approximately 62% P and 43% N, altering the condition of the ecosystem to become more mesotrophic. We also propose some management strategies to improve water quality in this lake ecosystem.

In-stream Physical Heterogeneity, Rainfall Aided Flushing, and Discharge on Stream Water Quality.

Implications of instream physical heterogeneity, rainfall-aided flushing, and stream discharge on water quality control have been investigated in a headwater stream of a climatic region that has contrasting dry and wet seasons. Dry (low flow) season's physical heterogeneity showed a positive correlation with good water quality. However, in the wet season, physical heterogeneity showed minor or no significance on water quality variations. Furthermore, physical heterogeneity appeared to be more complementary with good water quality subsequent to rainfall events. In many cases stream discharge was a reason for poor water quality. For the dry season, graywater inputs to the stream could be held responsible. In the wet season, it was probably the result of catchment level disturbances (e.g., regulation of ephemeral freshwater paths). Overall, this study revealed the importance of catchment-based approaches on water quality improvement in tandem with in-stream approaches framed on a temporal scale.

Micro-level crafting of institutions within integrated catchment management: Early lessons of adaptive governance from a catchment-based approach case study in England

There has been considerable interest and discussion surrounding institutional design and governance in the areas of planning, political studies and policy development and more recently natural resource management. Within England, like much of Europe, an integrated catchment management, called the catchment-based approach (CaBA), has been developed when implementing the European Union (EU) Water Framework Directive (WFD). This is seen as both a driver for stricter standards for water quality and ecological status in water course and encouraging the active involvement of stakeholders and communities in both planning and action. This paper analyses institutional design at the local level from the perspective of two concepts, namely institutional governance and social–ecological systems. The intension is to highlight synergies between the two concepts. Through this a new aspect of institutional design is revealed, the micro-level or ‘crafting’ of institutions by local actors. The paper identifies criteria that are associated with this aspect and analyses an integrated catchment case study in England. The paper concludes that the current policy approach in England, and potentially elsewhere in Europe, offers potential for the ‘crafting’ of institutions and at the local social–ecological systems scale this has potential for positive benefits such as great understanding and locally effective governance. Both would assist in achieving policy objectives, such as those of the WFD. The case study utilised an effective participatory approach that was, according to the criteria, robust and transferable in developing an adaptive governance approach.

Conservation of the freshwater pearl mussel (Margaritifera margaritifera) in the river Rede, UK: Identification of instream indicators for catchment-scale issues

The freshwater pearl mussel (Margaritifera margaritifera) is declining throughout its entire range. On the river Rede, North-East England, the population has been equally declining and shows no apparent recruitment. The study presented here aimed at characterizing water quality and habitat conditions for pearl mussels to identify possible indicators of pressures on the population and inform a restoration and conservation strategy. Water quality monitoring revealed levels of turbidity and suspended sediments to be above the limit set for functional pearl mussel rivers. Substrate sampling revealed silt was present at all sites. A loss of redox potential between the water column and the substrate occurred at all sites, indicating non suitable conditions for juvenile pearl mussels. These investigations suggest that fine sediment input in the river could be one of the factors preventing the development and survival of juvenile mussels while adults face water quality largely affected by high turbidity and high phosphate load. Restoration strategy for the Rede pearl mussel population should focus mainly on limiting sediment and nutrient input in the river throughout the catchment in order to improve habitat for juvenile pearl mussels. This work highlights the need for a catchment-based approach in order to succeed in the conservation of a fragile species.

IWRM in England: bridging the gap between top-down and bottom-up implementation

Implementation of IWRM has generally been approached mechanistically, with attention focused on identifying necessary conditions and developing useful tools and techniques. In contrast, this article examines alternative approaches to implementation in their totality, using IWRM in England as a case analysis. In England, the EU Water Framework Directive has been implemented through a ‘top-down’ approach but a ‘bottom-up’ approach has been adopted for catchment management. Both the Water Framework Directive and the catchment-based approach are consistent with the goals of IWRM, but their implementation arrangements are disconnected and operate at different scales. This example suggests that cross-scale interplay and bridging institutions are critical to the successful implementation of IWRM in complex governance settings.

The hydrological linkage of mountains and plains in the arid region of northwest China

Mountain regions supply a large amount of fresh water for the people in arid and semiarid regions, however, there is great uncertainty of the water quantification from mountains to lower areas. In order to assess the hydrological significance of mountains and the hydrological linkage of mountains and plains, the measured and simulated hydrological data of the arid region in northwest China were used in the present research which followed a catchment-based approach. Firstly, the Heihe River Basin, a well-documented area, was selected as a specific watershed to reveal the hydrological relationship between highlands (mountains) and lowlands (plains); and then, the significance and disproportion of mountain runoff of 8 river basins as cases in the arid region of northwest China were analyzed and compared following the above analysis. The results of the study showed that the proportion of mountain runoff in total basinal runoff (PMR) of most rivers is above 50%. The PMR are between 50%–95% in the rivers originated in the northern slope of the Tianshan Mountains where the aqueous vapor is relatively sufficient. And that, almost all the flow of the rivers originating from the Qilian Mountains, the southern slope of the Tianshan Mountains, and the northern slope of the Kunlun Mountains come from mountain regions. Also the PMR gradually increases from west to east in northwest China. The hydrological significance and disproportion of mountains water in the arid region of northwest China were given a systematic and thorough assessment, and the results could give potential guides for the scientific utilization of water resources in these regional areas for relieving the more and more serious shortage of water resources due to climate warming and population expansion.