Watershed Planning Research Articles

Large-Scale Multiobjective Optimization for Watershed Planning and Assessment

Large-Scale Multiobjective Optimization for Watershed Planning and Assessment

Rainfall-runoff modelling using GIS based SCS-CN method in umiam catchment region, Meghalaya, India

Rainfall-runoff is a crucial parameter and is often applied in assessing water resources. It is a significant constituent for recharging groundwater and plays an important role in understanding the hydrological characteristics of a basin for watershed management practices. In the current work, the soil conservation service-curve number (SCS–CN), coupled with GIS and remote sensing techniques, has been utilized to estimate the runoff and discharge in the Umiam Catchment area of Meghalaya for the years 2011 and 2020. This area receives heavy rainfall throughout the year, which contributes to the degradation of topsoil and the initiation of landslides. The rainfall-runoff modelling incorporates various thematic layers prepared in the GIS platform to calculate the weighted CN value. The antecedent moisture condition (AMC) was applied for CN correction. Both annual and monthly runoff and discharge were calculated for a total of four sub-watersheds. The result showed that land alteration and an increase in rainfall have been the predominant reasons for an increase in runoff in 2020 compared to 2011. Comparing both years, agricultural land, built-up, and open scrub have increased followed by shrinking open and dense forests. Sub-watersheds 2 and 4 had critical discharge changes of 75.95 and 75.82 cubic meters per second (cumec) from year 2011–2020 respectively. This study emphasizes the efficacy of SCS-CN method for simulating and estimating the runoff of a basin for better watershed planning and sustainable management at the regional level. It may also help in recognizing and examining the characteristics and volume of water resources.

Forest Disturbance Thresholds and Cumulative Hydrological Impacts

AbstractForest disturbance threshold is defined as a critical disturbance level (e.g., % of forest cover change) in forested landscapes above which significant hydrological impacts are detected. Determining disturbance thresholds is critically important for supporting forest management to ensure the sustaining of ecological and hydrological functions. However, there are very few quantitative evaluations of forest disturbance thresholds globally. In this study, we applied a well‐tested methodology (the modified double mass curve) to derive the long‐term, continuous hydrological response curves and then to quantify forest disturbance thresholds on annual streamflow in 42 forested watersheds in British Columbia, Canada. The results show that forest disturbance thresholds for significant and cumulative hydrological impacts vary from 7% to 52% of cumulative equivalent clear‐cut area with an average of 17% or from 8% to 52% of disturbed area with an average of 19%. Climate (inter‐annual and intra‐annual) and watershed properties exert critical controls on forest disturbance thresholds. Watersheds with greater snowfall proportions (more annual precipitation falling as snow), more desynchronizations (temporal mismatching) of energy demand and water supply at the intra‐annual scale, less diverse ecosystems, and larger watershed sizes have lower forest disturbance thresholds. Given the present forest disturbance levels in the central interior of British Columbia, about half (53%) of the forested watersheds have already crossed the average disturbance threshold. These results highlight that watershed planning and management using forest disturbance thresholds must carefully consider local climate and watershed properties. The methodology can be effectively and robustly extended elsewhere around the globe.

Assessment of flood risk in Söğütlü stream watershed of Trabzon province in Turkey using geographic information systems and analytic hierarchy process approach

Floods are significant natural disasters that have wide-ranging social, economic, and environmental consequences on a global scale. They lead to land degradation and increased erosion, which in turn negatively impacts water quality. In the present study, the Söğütlü stream watershed in the Eastern Black Sea Region of Turkey was chosen as the study area to create a flood risk map using Analytical Hierarchy Process and Weighted Overlay tools in the ArcGIS. The raster maps, including soil type, rainfall, landuse, slope, aspect, elevation, and distance to the stream, were utilized as the foundation for the analysis. The flood risk map generated from this analysis reveals five risk zones that is very high, high, moderate, low, and very low-risk zones. Statistical analysis was performed to evaluate the obtained data. The study results indicate that low and moderate areas encompass 95.98% of the watershed, while high-risk and very high-risk areas account for 4.02% of the watershed in the flood risk map of the Söğütlü watershed. It was observed that areas in close proximity to rivers, low slope end elevation were more susceptible to flooding. This study is great importance as it allows for the development of preventive, preparatory, and post-disaster plans before flood events occur by providing a flood risk map. Moreover, the creation of a flood risk map at the watershed scale helps planners in undertaking soil and water conservation efforts during watershed planning.

Defining the term watershed to reflect modern uses and functions as inter- and intra-connected socio-hydrologic systems

Despite the many programs focused on watershed education, the watershed concept is poorly understood, which can lead to a number of wide-ranging consequences from poor watershed planning and policy to inaccurate scientific studies. We argue that the definition of the term watershed, and the images that accompany the definition, contribute to these misunderstandings. The definition has remained very much the same since it was first documented in Europe in the mid-18th century. However, watershed uses and functions have evolved considerably in the past three centuries, notably in the many ways water moves within and across traditionally-defined watershed boundaries. In this study, content analyses of the definitions of the term watershed from textbooks and online sources, and the accompanying images, highlight that watersheds are nearly universally defined as an area of land that drains to a point on a river. More than half the images that accompany these definitions depict forested landscapes or high mountain relief. While over one half of online images depict human activities or developed landscapes, few textbook images do. These incomplete definitions and idealized images do not reflect the diversity of landscapes and watershed functions. The narrow description can contribute to an individual’s disconnection to their own watershed. Furthermore, the description of watersheds as lumped areas, rather than inter- and intra-connected socio-hydrologic systems, misses a fundamental element of the watershed concept: that activities at every point in a watershed impact all points downstream and are impacted by activities at all points upstream. Thus, we propose a revised definition of a watershed that better captures this connectivity: a watershed defines the boundaries of a system of hydrologically connected people, places, and things.

Assessment of surface water dynamics through satellite mapping with Google Earth Engine and Sentinel-2 data in Manipur, India

Abstract Accurate surface water mapping is crucial for watershed planning and safeguarding regional water resources. The study aimed to extract the extent of seasonal surface water, focusing on selected districts of Manipur, northeast India from 2016 to 2021, utilizing Sentinel-2 data in the Google Earth Engine (GEE) platform. Employing multiple indices and the Random Forest classifier, the methodology addressed challenges such as cloud and shadow interference, particularly in high-altitude regions. Results revealed Bishnupur had the maximum surface water extent (124 km2) and Tengnoupal had the minimum (0.24 km2) during the study period. A notable 6% gain in Bishnupur surface water was observed from pre- to post-monsoon in 2016, while changes in other districts were negligible. Conversely, a maximum loss of 7% occurred in Bishnupur during pre-monsoon from 2016 to 2021. Overall, post-monsoon expansion exceeded that of pre-monsoon in all districts. Discrepancies were evident in both seasons in 2021. The applied techniques proved reliable and innovative, ensuring accurate surface water extent mapping. The GEE platform facilitated enhanced access to satellite data, significantly expediting processing through machine learning algorithms. The findings of this study have the potential to inform surface water planning and management, offering valuable insights for efficient resource utilization.

Effect of Land Use on Stream Water Quality and Biological Conditions in Multi-Scale Watersheds

Understanding the relation between watershed land use and stream conditions is critical for watershed planning and management. This study investigated the effects of land use on stream water quality and biological conditions in sub-watersheds and micro-watersheds across the Han River watershed in South Korea. We developed random forest models for each water quality and biological indicator using the proportions of urban, agricultural, and forested areas. Our results indicate that water quality and biological indicators were significantly affected by forest area at both scales, and the sub-watershed models performed better than the micro-watershed models. Accumulated local effects were used to interpret the effect of each explanatory variable on the response variable. The plots for water quality and biological indicators with proportions of watershed land use demonstrated similar patterns at both scales, although the relation between land use and stream conditions was slightly more sensitive in micro-watersheds than in sub-watersheds. Urban and agricultural areas showed a lower proportion of water quality and biological condition variability in the micro-watersheds than in the sub-watersheds, while forests showed the opposite results. The findings of this study suggest that different spatial scales should be considered when developing effective watershed management strategies to maintain stream ecosystems.

Sediment connectivity in a hot and humidity tropical watershed: Contribution to environmental planning and management

This study aims to identify and analyze the sediment connectivity in the Duas Bocas River watershed (BHRDB), in the Metropolitan Region of Greater Vitória (RMGV/Brazil), for the year 2019 and simulate an environmental degradation scenario for the watershed. For the modeling of sediment connectivity, a land use and land cover map from 2019 was used, followed by an environmental degradation scenario where the Atlantic Forest was replaced by exposed soil. The digital elevation model has a spatial resolution of 5 × 5m. The Index of Connectivity (IC) for the year 2019 ranged from −11.32 to 0.49, with lower values in the upper portion of the watershed, which is protected by the Atlantic Forest vegetation, minimizing the possibility of sediment production and transfer to the river. Regarding the environmental degradation scenario, the IC ranged from −11.32 to 1.68, with the highest IC occurring in the area of exposed soil in the upper portion of the watershed that was previously protected by the Atlantic Forest. It was also found that the estimation of IC is sensitive to the spatial resolution of the digital elevation model, making it challenging to assess the plain area near the outlet of BHRDB. The geospatial variability of sediment connectivity highlighted the importance of maintaining forests in headwater areas in relation to soil degradation in tropical environments. The IC proved to be an important tool for developing environmental scenarios, contributing to the management and environmental planning of watershed.

Watershed prioritization of drainage basins based on geomorphometric parameters, Neyyar watershed, India

Prioritisation of sub-watersheds (SWs) is becoming increasingly important in the conservation of natural resources, particularly in watershed planning. In this study, sub-watershed for the Neyyar basin was prioritised using three methods: morphometric analysis, principal component analysis (PCA) and hypsometric analysis. Morphometric analysis and hypsometric analysis were carried out using remote sensing (RS) and geographic information system (GIS) techniques, while PCA was performed for dimensionality reduction of morphometric parameters. The watershed was divided into 11 sub-watersheds (SW1–SW11), and each sub-watershed was given priority. To rank and prioritise SWs, 15 morphometric parameters were selected from the quantitative measures of morphometric analysis, including linear, relief, and areal. PCA was used to rank and prioritise SWs based on three highly correlated morphometric parameters. The hypsometric integral (HI) values were determined using the elevation relief ratio approach, and HI values were utilised to prioritise SWs. For both methods, such as morphometric analysis and PCA, a higher priority has been given to SW1. Using hypsometric analysis, higher priorities have been assigned to SW1, SW7, SW8, SW9, SW10 and SW11. The most common SWs that belong to the same priority of SWs and have a high correlation between them among the three methods are SW1, SW2, and SW5.The results of this analysis indicate that SW1 is a common high priority area with a significant risk of soil erosion, runoff and peak discharge. Therefore, decision-makers may utilise the high-priority sub-watershed to guide planning and development, measure conservation efforts and manage the land to prevent.

Water for life in Alberta, Canada

Water is integral to Alberta’s economy, grounded in agriculture, power generation, extractive industry, tourism, and recreation. In 2003, the Government of Alberta released the Water for Life Strategy (the Strategy) amidst growing public concerns over multiple impacts on provincial water resources. The Strategy is a framework document guiding the development of watershed plans across the provincial landscape to be implemented by Watershed Protection and Advisory Committees (WPACs). This paper explores the extent to which First Nations in Alberta were included in the government’s development of the Strategy and in the implementation of the Strategy by the WPACs. Our research data was gathered through key informant interviews with WPAC personnel as well as content analysis of relevant planning documents from provincial and WPAC sources. The research results point to an absence of First Nations inclusion in both the development of the provincial water Strategy as well as the implementation of the Strategy through the WPAC policies and plans. The results also identify institutional gaps and opportunities by which the provincial government and the WPACs may engage more effectively and inclusively with Indigenous communities. From our analysis, we recommend a series of institutional arrangements to advance far greater inclusion of Indigenous voices and recognition of Indigenous peoples as rights-holders, in watershed planning in Alberta.

Morphometric analysis of watershed

The analysis of drainage basins or watersheds based on morphometric parameters is highly significant for effective watershed planning. It provides valuable insights into the relationships between different characteristics within a given area. Although numerous technical papers have explored this field of study, there is currently no standardized classification system and clear interpretation for each parameter. Consequently, evaluating the significance of individual morphometric parameters can be confusing. This paper aims to address this issue by offering a comprehensive understanding of the meaning behind the values of various morphometric parameters, along with relevant contextual information. A critical review is provided for each classification, including the range of values and their implications. Emphasizing the importance of data quality, covering aspects such as data preparation, scale, and level of mapping detail is also done. This review paper is intended to provide a comprehensive explanation that will assist future researchers in their morphometric analysis studies.

Soil erosion variations along land use and land cover dynamics in Matenchose watershed, Rift Valley Basin, Southern Ethiopia

AbstractThe global community recognizes land use and land cover change (LULC) as a primary cause of ecological modification that has a considerable impact on natural resources, particularly soil and water resources. The aim of this research was to investigate land use change's influences on soil erosion in the Matenchose watershed of Ethiopia in 1991, 2003, and 2020. The maximum likelihood classification (MLC) method was used in the study for supervised image analysis. Soil erosion was estimated using the geographic information system (GIS), remote sensing, and the Revised Universal Soil Loss Equation (RUSLE) model. According to the LULC data from 1991, the watershed was mostly covered by grassland (35%), while in 2003 and 2020, it was typically enclosed by cultivated land (36%) and (52%), respectively. The watershed's mean annual soil erosion rate grew significantly from 13 t/ha in 1991 to 18 t/ha in 2003 to 21 t/ha in 2020. Based on the current soil loss rate result, the Matenchose watershed was divided into five priority groups for soil management practices. In contrast, the watershed is made up of 2052 ha (21%) of areas with high to very high erosion risk, 3304 ha (33%) of areas with moderate erosion risk, and 2866 ha (29%) of areas with severe erosion risk. Based on the average annual rate of soil erosion, several vital subwatersheds were identified for potential future land management‐related actions. Over the 29 years, the area of grassland and forest decreased while agricultural and settlement areas expanded, and they contributed to the enhanced hazards of soil erosion. Particularly vulnerable to erosion are the watershed's hilly and steeper areas. The identified subwatersheds that are most at risk of erosion should be given priority for upcoming LULC initiatives, proper participatory watershed planning and management, and measures to conserve soil and water to preserve the Matenchose watershed's soil resources.

From scenario to roadmap: Design and evaluation of a web-based participatory watershed planning system for optimizing multistage implementation plans of management practices under stepwise investment

Planning multistage implementation plans, or roadmaps, based on the spatial distribution of a best management practice (BMP) scenario is essential for achieving watershed management goals under realistic conditions, such as stepwise investment plans that involve multiple stakeholders, including investors, economic and environmental beneficiaries. The state-of-the-art BMP roadmap optimization method can address this need for optimization but is over-specialized and complex to non-expert stakeholders. This study designed a user-friendly web-based participatory watershed planning system to assist a diverse group of stakeholders in reaching a consensus on optimal roadmaps. The participatory process of stakeholders includes iteratively proposing stepwise investment constraints, submitting roadmap optimization tasks, analyzing spatiotemporal results from multiple perspectives, and selecting preferred roadmaps. The proposed system design separates the participatory process of non-expert stakeholders from the specialized modeling process of constructing simulation-optimization tools for BMP roadmaps, which is done in advance by professional modelers and encapsulated as webservices on the server side. The webservices expose a small set of essential parameters to lower barriers to use. The interactive participatory process is presented to stakeholders through web browsers with an easy-to-use interface. The system design was evaluated by implementing an agricultural watershed planning system for soil erosion reduction and conducting a role-playing experiment involving three groups of stakeholders with different standpoints in proposing investment constraints. The experimental results show that the optimal roadmap sets exhibit progressive improvements across three-round optimizations started by different stakeholders, effectively capturing the varying perspectives of stakeholders and facilitating consensus-building among them. The idea of system design and example implementation can serve as a valuable reference for developing related user-friendly environmental decision support systems.

Multi-decadal changes in river morphology in an urbanizing watershed: Highland Creek, Toronto, Canada

Urban land development causes significant changes to river channel form and function. Outcomes are strongly conditioned by local circumstances although responses such as channel enlargement and incision are common but are highly variable in extent and detectability. Many case studies focus on small watersheds (or short reaches) and before-after conditions, and direct causation and temporal trajectories of change are not well known but often presumed to be a single step change and response. Well-documented examples in fully-urban, larger watersheds are rare, and rarer still are cases covering the full trajectory from pre-urban to fully urban land cover with accompanying data on the direct drivers of change such as discharge and stream power. Highland Creek, Toronto, has a drainage area of 102 km2 and between the early 1950s and 2000s underwent a land cover change from agricultural to completely urban in very low relief terrain with channels in narrow valleys incised locally into glacial sediments. Streamflow monitoring, land cover data and aerial photography over this seven-decade period, along with a calibrated runoff model and digital elevation data, give a complete picture over multiple epochs of the causes and changes in fluvial hydrology and geomorphology. The complete transformation of the flow regime, along with channel straightening and steepening, resulted in increases in average stream power (total and specific) of the order of ten and six times, respectively. The channel is now exceptionally energetic with maximum total and specific stream power for 2-year flood approaching 5000 Wm−1 and 300 Wm−2, respectively. The semi-alluvial and supply-limited character of the channels is also influential. Channel response is variable along the 20–25 km of channel measured and is notably different between the sub-watersheds, related to timing of development and its intersection with engineering intervention, and changing conceptions of the channel over time. In places the channel widened by a factor of four or five and changed from high sinuosity meanders to wide, bar-chute morphology, consistent with regime expectations for gravel-bed channels. In other places the process of urbanization has involved progressive engineering of the channel to convey stormwater (channelized), protect infrastructure and mitigate erosion, so that responses in these reaches are much more restricted and fluvial functions such as bend and bar development have been eliminated. Substantial channel transformation can be seen to have occurred episodically resulting from two major flood events as well as the increases in magnitude and frequency of peak flows, which limit post-flood recovery. Urbanization effects and consequences have developed gradually over a long period, rather than in a single urbanization step change, and they do not match simple models of channel evolution. In many ways urbanization of the river is ongoing, particularly in the form of geomorphically-referenced design of the channels as a response to damage from large floods and overall institutional watershed planning. The ongoing urbanization story of Highland Creek illustrates some extreme effects of urbanization as well as the complexity and contingency of response to the physical and institutional processes influencing the trajectory of urban river evolution.

Informing Volunteer Water Quality Monitoring Program Design and Watershed Planning: Case Study of StreamSmart Data Analysis in the Upper White River Basin, Arkansas

AbstractThe watershed group H2Ozarks founded the StreamSmart Citizen Science Program to establish baseline and long‐term water quality data for the Upper White River Basin, Arkansas. StreamSmart volunteers collect water samples and conduct habitat and macroinvertebrate community assessments at >20 sites across a land use‐land cover (LULC) gradient. Since 2020, H2Ozarks has adaptively assessed the program to ensure that the investment in water quality data meets core goals, with particular interest in planning tools and aligning expectations of volunteer effort with the level of training and support. Study objectives were to use StreamSmart data to 1) facilitate understanding of water quality response to stressors in the basin using a range of methods (Spearman rank correlation, non‐parametric changepoint analysis, and categorical and regression tree analysis) and 2) explore implications for program design and watershed planning. Water chemistry‐LULC relationships were in‐line with prior regional studies, as well as global patterns. Detected thresholds and hierarchy provide potential targets for managing LULC change to protect water quality, but further analysis is warranted to refine these relationships. Macroinvertebrate stressor‐response was most detectable for sensitive and less sensitive taxa and for habitat index components, suggesting potential to streamline these programmatic elements. Study findings for StreamSmart should also be informative for other small‐scale volunteer monitoring programs with limited resources, but which actively evaluate the types of data and program activities that yield a maximum scientific return on investment.

When is Aquatic Resource Type Conversion Appropriate: A Framework for Cleaning Sand out of the Gears and a Case Study for McInnis Marsh

Wetland and stream restoration projects may sometimes involve converting one “type” of aquatic habitat to another “type” (e.g., managed salt ponds into tidal marshes, depressional wetlands into streams, marsh into transition zone habitat). This “type conversion” may be necessary and beneficial in the context of addressing watershed plans or regional restoration goals, or in achieving resiliency to climatic changes (Goals Project 2015). Conversion can also occur through other large-scale, complex actions (e.g., mitigation banking initiatives). Whether driven by habitat restoration goals or compensatory mitigation needs or both, regulatory oversight typically governs the process. Holistically assessing such conversion through the regulatory lens is challenging for permitting programs. The challenge stems from how to accurately determine the overall value of an aquatic resource based on site-specific ecological properties and in the context of larger regional ecosystem management and goals. This is further compounded when assessing aquatic habitats that provide intrinsically different functions and services. Assessments must also account for the fact that wetlands and streams are not static ecosystems, but rather dynamically changing through time due to natural and anthropogenic factors, many of which are difficult to control or even accurately assess (e.g., sea level rise). These challenges are further exacerbated due to urbanization, conflicting human-environment goals, and the evolving state of habitat restoration science. Type conversion (i.e., replacing one aquatic type with a different aquatic habitat type) is recognized by agencies as a “sand in the gears” problem that can stymie planning and permitting because such actions typically require multiple agency authorizations (which may or may not be consistent with internal policies), habitat resource trade-offs, and consensus on ecosystem goals. The lack of consistent, defensible analysis based on transparent evaluation has been shown to impede critically needed habitat restoration (Bourgeois 2018; SFBRA 2022). To address this challenge, an interagency team of federal and state regulators and resource managers in California developed a structured and transparent approach for evaluating the appropriateness of aquatic resource type conversion. The resulting framework can support project planning and inform regulatory evaluation by helping to answer: 1) what loss or gain of function is expected from various aquatic resource type conversions, and 2) whether conversion might be ecologically (or functionally) appropriate. The framework is not intended to inherently value one type of aquatic resource over another, nor to supersede regulatory mandates. Rather, the intent is to support agencies’ technical and regulatory decisions by providing a standardized, transparent set of tools and approaches that can inform discussions between agencies and with project proponents during the project evaluation phase, with a goal of ensuring that projects are not only permittable, but environmentally beneficial. The framework consists of three modules that can be done either sequentially or in parallel. Together they can be used to assess the feasibility/suitability, functions, and regional context of a proposed type conversion project (Figure 1).

When is Aquatic Resource Type Conversion Appropriate: A Framework for Cleaning Sand out of the Gears and a Case Study for McInnis Marsh

Wetland and stream restoration projects may sometimes involve converting one “type” of aquatic habitat to another “type” (e.g., managed salt ponds into tidal marshes, depressional wetlands into streams, marsh into transition zone habitat). This “type conversion” may be necessary and beneficial in the context of addressing watershed plans or regional restoration goals, or in achieving resiliency to climatic changes (Goals Project 2015). Conversion can also occur through other large-scale, complex actions (e.g., mitigation banking initiatives). Whether driven by habitat restoration goals or compensatory mitigation needs or both, regulatory oversight typically governs the process. Holistically assessing such conversion through the regulatory lens is challenging for permitting programs. To address this challenge, an interagency team of federal and state regulators and resource managers in California developed a structured and transparent approach for evaluating the appropriateness of aquatic resource type conversion. The resulting framework can support project planning and inform regulatory evaluation by helping to answer: 1) what loss or gain of function is expected from various aquatic resource type conversions, and 2) whether conversion might be ecologically (or functionally) appropriate. The intent is to support agencies’ technical and regulatory decisions by providing a standardized, transparent set of tools and approaches that can inform discussions between agencies and with project proponents during the project evaluation phase, with a goal of ensuring that projects are not only permittable, but environmentally beneficial.

RAINFALL-RUNOFF SIMULATION OF A SUB-CATCHMENT USING HEC-HMS

Hydrological data in the form of stream flow is very scarce in most developing countries. This affects the planning and management of urban watersheds. Therefore, it is necessary to estimate peak discharge from rainfall using hydrologic models based on some measurable watershed characteristics. This study aims to model the rainfall-runoff process from a typical urban watershed using Hydrologic Engineering Center Hydrological Modeling System (HEC-HMS) software. The catchment basin has a total area of 21.91 km2, and a dendritic stream system. Soil Conservative Services (SCS) Curve number was used for getting excess rainfall from total rainfall, SCS dimensionless unit hydrograph for converting the excess rainfall to direct runoff and Muskingum for the channel routing. The rainfall-runoff simulation was conducted using six (6) rainfall events. Model calibration and validation were done using optimized parameters and the result shows a reasonable fit between the observed and simulated hydrograph. The model result has an RMS error of 1.5 m3/s, and a Nash-Sutcliff of 0.585. It is concluded that the model can be used to predict runoff from rainfall with reasonable accuracy. The result can be used for watershed planning and management.Keywords: HEC HMS, rainfall, runoff

Impact Assessment of Soil and Water Conservation Measures on Carbon Sequestration: A Case Study for the Tropical Watershed Using Advanced Geospatial Techniques

A sustainable method for protecting natural resources is the adoption of recommended soil and water conservation (SWC) measures. SWC measures are well recognized for their effective soil protection and water harvesting. Unfortunately, their significance in climate change mitigation has yet to receive global attention. The present study was conducted to highlight the applicability of SWC measures for carbon management in watersheds. In this study, the impact of SWC measures on land cover, soil erosion, carbon loss, and carbon sequestration were investigated using advanced techniques of remote sensing (RS) and geographic information systems (GIS). The study was conducted in the Central Mahatma Phule Krishi Vidyapeeth (MPKV) campus watershed, located in the rainfed region of Maharashtra, India. The watershed is already treated with various scientifically planned SWC measures. Following the implementation of conservation measures in the watershed, average annual soil loss was reduced from 18.68 to 9.41 t ha−1yr−1 and carbon loss was reduced from 348.71 to 205.52 kgC ha−1yr−1. It was found that deep continuous contour trenches (DCCT) constructed on barren, forest, and horticultural land have the soil carbon sequestration rates of 0.237, 0.723, and 0.594 t C ha−1yr−1, respectively, for 0–30 cm depth of soil. Similarly, compartment bunds constructed on agricultural land have a soil carbon sequestration rate of 0.612 t C ha−1yr−1. These findings can be of great importance in the planning and management of climate-resilient watersheds.

Integrating principles and tools of decision science into value-driven watershed planning for compensatory mitigation.

Several environmental policies strive to restore impaired ecosystems and could benefit from a consistent and transparent process-codeveloped with key stakeholders-to prioritize impaired ecosystems for restoration activities. The Clean Water Act, for example, establishes reallocation mechanisms to transfer ecosystem services from sites of disturbance to compensation sites to offset aquatic resource functions that are unavoidably lost through land development. However, planning for the prioritization of compensatory mitigation areas is often hampered by decision-making processes that fall into a myopic decision frame because they are not coproduced with stakeholders. In this study, we partnered with domain experts from the North Carolina Division of Mitigation Services to codevelop a real-world decision framework to prioritize catchments by potential for the development of mitigation projects following principles of a structured decision-making process and knowledge coproduction. Following an iterative decision analysis cycle, domain experts revised foundational components of the decision framework and progressively added complexity and realism as they gained additional insights or more information became available. Through the course of facilitated in-person and remote interactions, the codevelopment of a decision framework produced three main "breakthroughs" from the perspective of the stakeholder group: (a) recognition of the problem as a multiobjective decision driven by several values in addition to biogeophysical goals (e.g., functional uplift, restoring or enhancing lost functionality of ecosystems); (b) that the decision comprises a linked and sequential planning-to-implementation process; and (c) future risk associated with land-use and climate change must be considered. We also present an interactive tool for "on-the-fly" assessment of alternatives and tradeoff analysis, allowing domain experts to quickly test, react to, and revise prioritization strategies. The decision framework described in this study is not limited to the prioritization of compensatory mitigation activities across North Carolina but rather serves as a framework to prioritize a wide range of restoration, conservation, and resource allocation activities in similar environmental contexts across the nation.