River Health Evaluation Based on the Fuzzy Matter-Element Extension Assessment Model

Abstract

Society benefits immeasurably from rivers [1], and more and more water conservancy projects have improved more and more people's lives -especially regarding aspects of flood control and water supply in developing and undeveloped countries [2]. But with the rapid development of the economy, increasing human activities, and climate changes, river ecosystem health degrades day by day in many regions, represent by the sharp imbalance between water resource supply and demand, natural wetland shrinkage, serious river contamination, deductions in estuary runoff, and the disappearance of endemic fish, etc., all influence the sustainable development of nature, the economy, and society [3][4][5][6][7][8][9].Pol. J. Environ. Stud. Vol. 26, No. 3 (2017) The measured values of river health indexes that are not necessarily in the same range of a certain health grade level cause the problem of how to classify the actual status of river health. To solve such incompatibility and evaluate the health condition of a river ecosystem objectively we can use the river health integrated index (RHI), which was determined by the fuzzy matter-element extension assessment model (FMEAM). FMEAM was established by combining the fuzzy matter-element extension assessment method with the proposed aggregative index system. By employing the model above, as well as data from the 1980s, 1990s, and 2000s, we evaluated the health state of the Luanhe River. The results showed that the Luanhe River was in a sub-healthy state in the 1980s and in an unhealthy state in the 1990s and 2000s. The reasons leading to the Luanhe River's health degradation have been analyzed. Among them, water conservation projects' building and operations are the major influence factors. Waste water emissions, the expansion of urban built-up areas, over exploitation of groundwater, and other unreasonable human activities also intensified the river ecosystem degradation. Finally, countermeasures for the ecological restoration and protection of the river were put forward.

Urban River Health Analysis of the Jialu River in Zhengzhou City Using the Improved Fuzzy Matter-Element Extension Model

“…where k ij is the relation degree of the index value x i in j-th year. In accordance with previous research on the fuzzy matter-element extension model [6,51], a i represents the new threshold value between "very sick" and "sick", and b i represents the new threshold value between "healthy" and "sub-healthy" in Table 2, respectively.…”

“…The decline in the natural and economic functions of urban river ecosystems poses a serious threat to the health of urban rivers. As one of the most powerful areas of interaction between humans and natural ecosystems, the health issues pertaining to urban rivers have attracted widespread attention from governments and Non-governmental organizations (NGOs) [4][5][6]. Evaluations of urban river health can provide an effective method for diagnosing urban river health problems, with urban river health assessments gradually being applied to river protection.…”

“…According to the matter-element extension theory [6,50,51], uRHI can be obtained from the entropy weight of the index and the relation degree matrix. The uRHI of the urban river health assessment in the present study was calculated by the following formula:…”

Urban Water Ecosystem Health Evaluation Based on the Improved Fuzzy Matter‐Element Extension Assessment Model: Case Study from Zhengzhou City, China

“…Wenk studied ways to achieve the stability of urban water ecosystem by controlling, using, and comprehensively managing urban stormwater [29]. Evaluating water ecosystem health has mainly involved evaluating the river basin ecological health [30][31][32], and selecting indicators has been mainly based on the indicator species method of the natural ecosystem and systematic index evaluation [33].…”

A Vegetation Selection Model for Ecological Bank Protection Works based on Improved TOPSIS Method and Its Application

“…In this index system, the weights of each index were also given in Table 1. And indexes weights were determined by expert evaluation method [9]. …”