Increased sea water intrusion in the vicinity of Tidal Link Drain at south Sindh (Pakistan)

The Tidal Link Drain is a man made drain which delivers the drainage water across Pateji and Cholri Dhands into the Arabian Sea via Shah Samando creek. The Tidal Link is 41 Km long from its point of juncture with Kaddan Pateji Outfall Drain (KPOD) in the North-East up to Shah Samando Creek in the South-West. The vertical tidal range in the area is about 5 m. The tidal link was designed to carry about 3,118 cusecs of drainage waters. After completion of Tidal Link Drain, sea water intrusion and high erosion/sedimentation have been noticed at the tidal link and adjacent area due to changes in the hydraulic regime in the area. The devastation caused by tropical cyclone “2A” in May, 1999 in the Indus delta has also created some drastic morphological changes in the area. This physical process creates breaches in the Tidal link drain between RD-30 and RD-125. These openings allow free exchange of water between the tidal link drain, Dhands and the Rann of Kutch. The analysis of tidal behavior, tidal current measurements and water samples collected in the study area shows that a small tidal creek type system of drainage channels has now been developed in Cholri Dhand and this system of channels is now used to flush water during ebb tide from surrounding Dhands of LBOD through Tidal Link Drain. It is observed that the LBOD can now be described as a “New River” that is forming an “Estuary”, which is an integral part of the creek system of the coastal area. The tidal link now acts as a tidal stream in which tidal fluctuations are very much visible and the sea water is now approaching the land. The main problem concerning the LBOD outfall is the increased hydraulic gradient due to seawater intrusion. The LBOD run parallel to the Indus River and discharges the saline water at the same level (sea level) in an active creek area of the Shah Samando Creek. The same altered hydraulic gradient creates very strong ebb currents in the region, which are responsible for making breaches in the tidal link drain and erosion and accretion in the Dhands

Enhancing MPPT Performance in Partially Shaded PV Systems under Sensor Malfunctioning with Fuzzy Control

The shift towards sustainable energy sources is gaining momentum due to their environmental cleanliness, abundant availability, and eco-friendly characteristics. Solar energy, specifically harnessed through photovoltaic (PV) systems, emerges as a clean, abundant, and environmentally friendly alternative. However, the efficacy of PV systems is subjective depending on two critical factors: irradiance and temperature. To optimize power output, maximum power point tracking (MPPT) strategies are essential, allowing operation at the system’s optimal point. In the presence of partial shading, the power–voltage curve exhibits multiple peaks, yet only one global maximum power point (GMPP) can be identified. Existing algorithms for GMPP tracking often encounter challenges, including overshooting during transient periods and chattering during steady states. This study proposes the utilization of fuzzy sliding mode controllers (FSMC) and fuzzy proportional-integral (FPI) control to enhance global MPPT reference tracking under partial shading conditions. Additionally, the system’s performance is evaluated considering potential sensor malfunctions. The proposed techniques ensure precise tracking of the reference voltage and maximum power in partial shading scenarios, facilitating rapid convergence, improved system stability during transitions, and reduced chattering during steady states. The usefulness of the proposed scheme is confirmed through the use of performance indices. FSMC has the lowest integral absolute error (IAE) of 946.94, followed closely by FPI (947.21), in comparison to the sliding mode controller (SMC) (1241.6) and perturb and observe (P&O) (2433.1). Similarly, in integral time absolute error (ITAE), FSMC (56.84) and FPI (57.06) excel over SMC (91.03) and P&O (635.50)