Generic Regular Decompositions for Parametric Polynomial Systems

This paper presents a generalization of our earlier work in [19]. In this paper, the two concepts, generic regular decomposition (GRD) and regular-decomposition-unstable (RDU) variety introduced in [19] for generic zero-dimensional systems, are extended to the case where the parametric systems are not necessarily zero-dimensional. An algorithm is provided to compute GRDs and the associated RDU varieties of parametric systems simultaneously on the basis of the algorithm for generic zero-dimensional systems proposed in [19]. Then the solutions of any parametric system can be represented by the solutions of finitely many regular systems and the decomposition is stable at any parameter value in the complement of the associated RDU variety of the parameter space. The related definitions and the results presented in [19] are also generalized and a further discussion on RDU varieties is given from an experimental point of view. The new algorithm has been implemented on the basis of DISCOVERER with Maple 16 and experimented with a number of benchmarks from the literature.Comment: It is the latest version. arXiv admin note: text overlap with arXiv:1208.611

Developing a Drought Planning Evaluation System in the United States

Drought is a normal part of the climate cycle, affecting every climate regime on the planet. Drought indicates a special period in which an unusual moisture scarcity causes a serious hydrological imbalance. Drought is related to the timing and effectiveness of the rains, high temperature, high wind, and low humidity. The typical impacts of drought may include dry lands, low or empty water-supply reservoirs, low groundwater levels (dried up wells), crop damage, and ensuing environmental degradation. In the United States, drought accounts for losses in the billions of dollars. In fact, a FEMA (1995) report estimates the average annual losses due to drought at $6-8 billion, on a par with hurricanes, making these the two most costly hazards impacting our country. Drought often affects several sectors (agriculture, recreation and tourism, energy, forestry, and others) at the same time and typically impacts large areas and many people. These impacts serve as indicators of our vulnerability and risk during extended periods of rainfall deficits. Our vulnerability to drought is affected by (among other factors) population growth and shifts, urbanization and sprawl, demographic characteristics, technology, water use trends, government policy, social behavior, and environmental awareness. These factors are continually changing, and society\u27s vulnerability to drought can increase or decrease in response to these changes. Although drought is a natural hazard, society can reduce its vulnerability and therefore lessen the risks associated with drought episodes. The impacts of drought, like those of other natural hazards, can be reduced through mitigation and preparedness. Planning ahead in an attempt to mitigate drought gives decision makers the chance to relieve the most suffering at the least expense. Reacting to drought in crisis mode decreases self-reliance and increases dependence on government and donors (Wilhite and Pulwarty, 2005). As a proof of concept approach, this paper looks into the process of comparing and evaluating state drought plans within the United States. The idea of evaluating (scoring) drought plans may be new, but similar methods have been applied to other hazards and in other planning fields, such as the environmental and urban/rural planning sectors (Baer 1997; Berke 2000; Brody 2003; Tang et a\. 2008). Even so, the planning profession itself has developed relatively few criteria for evaluating the quality of plans, so plan quality is difficult to define (Baer 1997). Now, and in a changing climate with changing vulnerabilities, Brody (2003) aptly notes that planners must be flexible, adapting and planning for changing conditions by gearing their efforts more toward uncertainty and surprise. Thus, the purpose of this paper is to assess the potential transferability of evaluation techniques in other fields and hazards to the evaluation of drought plans in the United States

Developing a Drought Planning Evaluation System in the United States

Drought is a normal part of the climate cycle, affecting every climate regime on the planet. Drought indicates a special period in which an unusual moisture scarcity causes a serious hydrological imbalance. Drought is related to the timing and effectiveness of the rains, high temperature, high wind, and low humidity. The typical impacts of drought may include dry lands, low or empty water-supply reservoirs, low groundwater levels (dried up wells), crop damage, and ensuing environmental degradation. In the United States, drought accounts for losses in the billions of dollars. In fact, a FEMA (1995) report estimates the average annual losses due to drought at $6-8 billion, on a par with hurricanes, making these the two most costly hazards impacting our country. Drought often affects several sectors (agriculture, recreation and tourism, energy, forestry, and others) at the same time and typically impacts large areas and many people. These impacts serve as indicators of our vulnerability and risk during extended periods of rainfall deficits. Our vulnerability to drought is affected by (among other factors) population growth and shifts, urbanization and sprawl, demographic characteristics, technology, water use trends, government policy, social behavior, and environmental awareness. These factors are continually changing, and society\u27s vulnerability to drought can increase or decrease in response to these changes. Although drought is a natural hazard, society can reduce its vulnerability and therefore lessen the risks associated with drought episodes. The impacts of drought, like those of other natural hazards, can be reduced through mitigation and preparedness. Planning ahead in an attempt to mitigate drought gives decision makers the chance to relieve the most suffering at the least expense. Reacting to drought in crisis mode decreases self-reliance and increases dependence on government and donors (Wilhite and Pulwarty, 2005). As a proof of concept approach, this paper looks into the process of comparing and evaluating state drought plans within the United States. The idea of evaluating (scoring) drought plans may be new, but similar methods have been applied to other hazards and in other planning fields, such as the environmental and urban/rural planning sectors (Baer 1997; Berke 2000; Brody 2003; Tang et a\. 2008). Even so, the planning profession itself has developed relatively few criteria for evaluating the quality of plans, so plan quality is difficult to define (Baer 1997). Now, and in a changing climate with changing vulnerabilities, Brody (2003) aptly notes that planners must be flexible, adapting and planning for changing conditions by gearing their efforts more toward uncertainty and surprise. Thus, the purpose of this paper is to assess the potential transferability of evaluation techniques in other fields and hazards to the evaluation of drought plans in the United States

Integrating the principles of strategic environmental assessment into local comprehensive land use plans in California

The lack of early integration with the planning and decision-making process has been a major problem in environmental assessment. Traditional project-based environmental impact assessment has inadequate incentives and capacities to incorporate critical environmental impacts at a broader temporal or spatial scale. While many applications have been geared towards implementing project-level environmental assessments, comparatively little research has been done to determine how to incorporate strategically critical environmental impacts into local planning. Although the principles of strategic environmental assessment (SEA) are not yet required in local planning in the United States, these principles create a theoretical framework for local environmental assessment. The objective of this study is to examine the ability of local plans to integrate and implement the key SEA principles. This study focuses on increasing the understanding of how and where to integrate environmental impacts into the local planning and decision-making process by converting the principles of SEA into specific planning tools, policies, and implementation strategies. This study develops a protocol with 112 indicators to measure the strengths and weaknesses of integrating strategic environmental assessment into local comprehensive land use plans. A random sample of 40 California local comprehensive land use plans and associated planning processes is evaluated based on this plan quality evaluation protocol. Statistical analysis and multiple regression models identify the factors affecting the quality of plans with respect to their ability to assess environmental impacts. The results identify the relative strengths and weaknesses of the ability of local jurisdictions to integrate the SEA principles. The results show that many strategically important environmental issues and tools are rarely adopted by current local plans. The regression analysis results further identify the effects of planning capacity, environmental assessment capacity, public participation and contextual variables on environmental assessment plan quality. The findings extend established planning theory and practice by incorporating strategic environmental considerations into the existing framework of what constitutes a high quality local land use comprehensive plan and suggest ways to improve plan quality

Using the electromagnetic induction survey method to examine the depth to clay soil layer (Bt horizon) in playa wetlands

Purpose Sediment accumulation has been and continues to be a significant threat to the integrity of the playa wetland ecosystem. The purpose of this study was to determine the vertical depth to the clay soil layer (Bt horizon) and thus to calculate the thickness of sediments accumulated in playa wetlands. Materials and methods This study used the electromagnetic induction (EMI) survey method, specifically EM38-MK2 equipment, to measure the vertical depth to the clay soil layer at the publicly managed wetlands in the Rainwater Basin, Nebraska, USA. Results and discussion The results indicated that the depth to the clay soil layer ranges from 21 to 78 cm (n = 279) with a mean sediment thickness of 39 cm. The annual sediment deposition rate since human settlement in the 1860s was calculated to be 0.26 cm year−1. The results provided science-based data to support future wetland restoration planning and the development of decision support tools that prioritize conservation delivery efforts. Conclusions Our research confirmed that the EMI technique is effective and efficient at determining the depth to the Bt horizon for playa wetlands. Additionally, these results supported previous studies and continue to indicate that a large amount of sediment has accrued in these playa wetlands within the Rainwater Basin area since settlement.Wetland restoration ecologists can use this information to prioritize future wetland restoration work that intends to remove culturally accumulated sediments above the clay soil layer. These findings provided a contemporary summary of wetland soil profile information that is typically used to develop restoration plans. This research also filled the critical knowledge gap about the thickness of the upper soils and the depth to Bt in publicly managed wetlands

Using Sentinel-2 Imagery and Machine Learning Algorithms to Assess the Inundation Status of Nebraska Conservation Easements during 2018–2021

Conservation easements (CEs) play an important role in the provision of ecological services. This paper aims to use the open-access Sentinel-2 satellites to advance existing conservation management capacity to a new level of near-real-time monitoring and assessment for the conservation easements in Nebraska. This research uses machine learning and Google Earth Engine to classify inundation status using Sentinel-2 imagery during 2018–2021 for all CE sites in Nebraska, USA. The proposed machine learning approach helps monitor the CE sites at the landscape scale in an efficient and low-cost manner. The results confirmed effective inundation performance in these floodplain or wetland-related CE sites. The CE sites under the Emergency Watershed Protection- Floodplain Easement (EWPP-FPE) had the highest inundated area rate of 18.72%, indicating active hydrological inundation in the floodplain areas. The CE sites under the Wetlands Reserve Program (WRP) reached a mean annual surface water cover rate area of 8.07%, indicating the core wetland areas were inundated periodically or regularly. Other types of CEs serving upland conservation purposes had a lower level of inundation while these uplands conservation provided critical needs in soil erosion control. The mean annual surface water cover rate is 0.96% for the CE sites under the Grassland Reserve Program (GRP). The conservation of the CEs on uplands is an important component to reduce soil erosion and improve downstream wetland hydrological inundation performance. The findings support that the sites with higher inundation frequencies can be considered for future wetland-related conservation practices. The four typical wetland-based CE sites suggested that conservation performance can be improved by implementing hydrological restoration and soil erosion reduction at the watershed scale. The findings provided robust evidence to discover the surface water inundation information on conservation assessment to achieve the long-term goals of conservation easements

Recent morphodynamic evolution of the largest uninhibited island in the Yangtze (Changjiang) estuary during 1998-2014: Influence of the anthropogenic interference

Estuarine geomorphology worldwide has greatly changed in the Anthropocene due to intensive human inferences in river basin and within estuary, which has received increasing global concerns. Here, recent morphodynamic evolution of Jiuduan Shoal (JDS), the largest uninhabited island in the Yangtze (Changjiang) Estuary, and associated controlling factors were analyzed based on unique high-resolution seasonal-surveyed bathymetric data during 1998–2014. It can be indicated that JDS presents novel 12 and 48 months fluctuations though significant accretion was detected on high flats above −2 m. Meanwhile, morphodynamic evolution of JDS during 1998–2014 was divided into three stages: significant siltation on land-ward half of north JDS and expanding of Jiangya Shoal (JYS, part of JDS) tail, but less accretion at high flats from 1998 to 2002; continuous variations of JYS and reshape of seaward JDS with erosion band and heave appearance from 2002 to 2006; retentive alteration of JYS but recovery of erosion band and heave, together with redistribution of sand between high and low flats on seaward JDS after 2007. Moreover, river discharge could be likely the key factor controlling periodic characteristics of recent JDS evolution. Deep waterway project (DWP) dominates area increase of JDS by inducing accretion in north edge and south edge of Lower Shoal between 1998 and 2014